Rotor assembly, permanent magnet synchronous motor, traction system, and vehicle

Abstract

Embodiments of the present application provide a rotor assembly, a permanent magnet synchronous motor, a traction system, and a vehicle. The rotor assembly comprises: a rotating shaft; a rotor core fitted over the rotating shaft and provided with a plurality of permanent magnet slots uniformly distributed in the circumferential direction; permanent magnets provided in the permanent magnet slots; and a plurality of magnetically conductive blocks arranged corresponding to the plurality of permanent magnet slots, wherein each magnetically conductive block is arranged radially on the side of the corresponding permanent magnet slot close to the rotating shaft, and the magnetically conductive blocks are configured to move between a first position close to the permanent magnet slots and a second position distant from the permanent magnet slots, so as to adjust the magnetic field distribution of the rotor assembly.

Description

Rotor assembly, permanent magnet synchronous motor, traction system and vehicle

[0001] Cross Reference to Related Applications

[0002] The present application is based on the Chinese patent application No. 202411262612.8, filed on September 10, 2024, entitled “Rotor assembly, permanent magnet synchronous motor, traction system and vehicle”, and claims priority to the Chinese patent application No. 202411262612.8, and the entire contents of the Chinese patent application No. 202411262612.8 are hereby incorporated by reference into the present application.

[0003] The present application is based on the Chinese patent application No. 202411262919.8, filed on September 10, 2024, entitled “Rotor assembly, permanent magnet synchronous motor and vehicle”, and claims priority to the Chinese patent application No. 202411262919.8, and the entire contents of the Chinese patent application No. 202411262919.8 are hereby incorporated by reference into the present application.

[0004] The present application is based on the Chinese patent application No. 202411263012.3, filed on September 10, 2024, entitled “Rotor assembly, permanent magnet synchronous motor and vehicle”, and claims priority to the Chinese patent application No. 202411263012.3, and the entire contents of the Chinese patent application No. 202411263012.3 are hereby incorporated by reference into the present application.

[0005] The present application is based on the Chinese patent application No. 202411263089.0, filed on September 10, 2024, entitled “Rotor assembly, permanent magnet synchronous motor and vehicle”, and claims priority to the Chinese patent application No. 202411263089.0, and the entire contents of the Chinese patent application No. 202411263089.0 are hereby incorporated by reference into the present application.

[0006] The present application is based on the Chinese patent application No. 202411263845.X, filed on September 10, 2024, entitled “Rotor assembly, permanent magnet synchronous motor and vehicle”, and claims priority to the Chinese patent application No. 202411263845.X, and the entire contents of the Chinese patent application No. 202411263845.X are hereby incorporated by reference into the present application. TECHNICAL FIELD

[0007] The present application relates to the technical field of electric machines, and more particularly, to a rotor assembly, a permanent magnet synchronous motor and a vehicle. BACKGROUND

[0008] With the rapid development of power electronics technology and high-performance rare earth materials, permanent magnet synchronous motor has been widely applied due to its high power density and high efficiency. The rotor of the permanent magnet synchronous motor is excited by a rare earth permanent magnet. Since the excitation magnetic field is not adjustable, and is limited by the DC bus voltage and the inverter capacity, when the system exceeds the rated power, as the rotating speed rises, the back EMF of the stator winding rises. In order to ensure the operation at a higher speed, the rotor needs to be controlled by field weakening (also known as flux regulation). The flux regulation method in the related art includes AC pulse flux regulation, DC pulse flux regulation and mechanical flux regulation.

[0009] The AC pulse flux regulation is to apply a direct-axis excitation / de-excitation pulse current to the stator armature winding to realize the excitation / de-excitation of the permanent magnet, so as to adjust the air gap flux density and expand the operating speed of the motor.

[0010] The DC pulse flux regulation is to additionally provide a DC flux regulation winding on the motor stator or rotor for excitation / de-excitation of the permanent magnet.

[0011] The mechanical flux regulation is to provide a plurality of slots in the rotor core, and provide permanent magnets with the same polarity at both ends of the slots, wherein the outer side is fixed and the inner side is linked with a magnetic guide block to slide. When the rotating speed of the motor rises, the permanent magnet linked with the magnetic guide block moves to the direction close to the air gap under the action of centrifugal force, so that the magnetic resistance of the main magnetic pole leakage path is reduced, the leakage magnetic flux is increased, and the magnetic flux through the air gap is reduced, so as to reduce the air gap flux density when the motor operates at a high speed.

[0012] In the above-mentioned various methods, the field weakening current in the DC or AC pulse flux regulation causes high copper loss, which reduces the efficiency of the permanent magnet synchronous motor at high speed. Meanwhile, this method needs to add additional components in the circuit, which increases the cost. The existing mechanical flux regulation is a passive regulation, that is, the field weakening capability cannot be actively controlled. Moreover, the field weakening capability of this method is limited and cannot achieve the expected effect.

[0013] In addition, when a motor turn short fault occurs during high-speed operation of a vehicle, the motor stator three-phase winding is cut off and the rotor idles under the action of external force. At this time, the electromagnetic coupling between the motor stator and the rotor has not been eliminated, and the winding coil will continue to cut the permanent magnet field to generate a large induced electromotive force, which causes a large circulating current in the short-circuit winding coil. On the one hand, this current will cause the winding to heat up and even catch fire, and on the other hand, the large short-circuit current will generate a pulsating magnetic field, which interacts with the rotor permanent magnet field to generate vibration, directly endangering the safe operation of the vehicle. SUMMARY

[0014] The present application mainly provides a rotor assembly, a permanent magnet synchronous motor, a traction system and a vehicle. The various aspects related to the embodiments of the present application will be introduced below.

[0015] In a first aspect, a rotor assembly is provided, comprising: a rotating shaft; a rotor core sleeved on the rotating shaft and having a plurality of permanent magnet slots uniformly distributed in a circumferential direction; a plurality of permanent magnets arranged in the permanent magnet slots; a plurality of magnetic conductive blocks corresponding to the plurality of permanent magnet slots, each of the magnetic conductive blocks being arranged on a side of the corresponding permanent magnet slot close to the rotating shaft in a radial direction; the magnetic conductive blocks are configured to move between a first position close to the permanent magnet slots and a second position away from the permanent magnet slots, so as to adjust a magnetic field distribution of the rotor assembly.

[0016] According to the above technical means, by arranging the magnetic conductive blocks corresponding to the plurality of permanent magnets in the rotor assembly, and adjusting the positions of the magnetic conductive blocks to generate different leakage magnetic fields, the adjustment of the permanent magnet magnetic field is realized, the speed regulation range of the permanent magnet synchronous motor is ensured to be wide, the power factor of the permanent magnet motor at high speed is improved, and the motor iron loss can be eliminated or reduced. When the magnetic conductive blocks are moved to one end close to the permanent magnets, the rotor permanent magnet magnetic field can be concentrated in the rotor assembly, so that a large counter electromotive force can be avoided in the conductor when the motor is counter-tracked, and the safety of the traction system when the stator winding is short-circuited is ensured.

[0017] In a second aspect, a permanent magnet synchronous motor is provided, comprising a rotor assembly and a stator assembly, the rotor assembly being the rotor assembly of the first aspect.

[0018] In a third aspect, a permanent magnet synchronous motor is provided, applied to a power system of an urban rail transit vehicle, the vehicle power system comprising a plurality of permanent magnet synchronous motors for providing power for the vehicle, the permanent magnet synchronous motor comprising a rotor assembly and a stator assembly, the rotor assembly comprising: a rotating shaft; a rotor core sleeved on the rotating shaft and having a plurality of permanent magnet slots uniformly distributed in a circumferential direction; a plurality of permanent magnets arranged in the permanent magnet slots; a plurality of magnetic conductive blocks corresponding to the plurality of permanent magnet slots, each of the magnetic conductive blocks being arranged on a side of the corresponding permanent magnet slot close to the rotating shaft in a radial direction; the magnetic conductive blocks are configured to: when the vehicle is in an idle running condition, the magnetic conductive blocks are located at a first position close to the permanent magnet slots, so as to reduce the iron loss of the permanent magnet synchronous motor in the idle running condition; when the vehicle is in a traction condition, the magnetic conductive blocks are located at a second position away from the permanent magnet slots, so as to increase the air gap magnetic field strength between the rotor assembly and the stator assembly.

[0019] In a fourth aspect, a power system is provided, applied to an urban rail transit vehicle, for providing power for the vehicle, the power system comprising the permanent magnet synchronous motor of the third aspect.

[0020] In a fifth aspect, there is provided a railway vehicle, the vehicle comprising the permanent magnet synchronous motor according to the third aspect or the power system according to the fourth aspect.

[0021] In a sixth aspect, there is provided a permanent magnet synchronous traction motor for a traction system of a locomotive, the permanent magnet synchronous traction motor comprising a rotor assembly and a stator assembly, the rotor assembly comprising: a rotor shaft; a rotor core sleeved on the rotor shaft, having a plurality of permanent magnet slots uniformly distributed along a circumferential direction; a plurality of permanent magnets arranged in the plurality of permanent magnet slots; and a plurality of magnetic conductive blocks corresponding to the plurality of permanent magnet slots, each of the plurality of magnetic conductive blocks being arranged at a side of a corresponding permanent magnet slot close to the rotor shaft along a radial direction, the plurality of magnetic conductive blocks being configured to move between a first position close to the permanent magnet slot and a second position away from the permanent magnet slot according to an operating speed of the locomotive, to adjust a magnetic field distribution of the rotor assembly, so that the permanent magnet synchronous traction motor outputs constant power when driving the locomotive to operate within a range of the operating speed.

[0022] In a seventh aspect, there is provided a traction system for a locomotive, the traction system comprising the permanent magnet synchronous traction motor according to the sixth aspect.

[0023] In an eighth aspect, there is provided a locomotive, comprising the permanent magnet synchronous traction motor according to the sixth aspect or the traction system according to the seventh aspect.

[0024] In a ninth aspect, there is provided a power system for a train, the power system comprising a plurality of permanent magnet synchronous motors for driving the train to operate, each of the plurality of permanent magnet synchronous motors comprising a rotor assembly and a stator assembly, the rotor assembly comprising: a rotor shaft; a rotor core sleeved on the rotor shaft, having a plurality of permanent magnet slots uniformly distributed along a circumferential direction; a plurality of permanent magnets arranged in the plurality of permanent magnet slots; and a plurality of magnetic conductive blocks corresponding to the plurality of permanent magnet slots, each of the plurality of magnetic conductive blocks being arranged at a side of a corresponding permanent magnet slot close to the rotor shaft along a radial direction, the plurality of magnetic conductive blocks being configured to switch between a first position close to the permanent magnet slot and a second position away from the permanent magnet slot, to adjust a magnetic field distribution of the rotor assembly; the power system being configured to, in a case where an inter-turn short circuit fault occurs in a target permanent magnet synchronous motor of the plurality of permanent magnet synchronous motors, switch the magnetic conductive blocks in the target permanent magnet synchronous motor to the first position, to short-circuit a main magnetic flux of the target permanent magnet synchronous motor, so that the target permanent magnet synchronous motor is taken out of service.

[0025] In a tenth aspect, there is provided a train, comprising the power system according to the ninth aspect.

[0026] In an eleventh aspect, a permanent magnet synchronous motor is provided for use in a mobile device, the permanent magnet synchronous motor comprising a stator assembly and a rotor assembly, the rotor assembly comprising: a rotor shaft; a rotor core sleeved on the rotor shaft and having a plurality of permanent magnet slots uniformly distributed in a circumferential direction; a plurality of permanent magnets arranged in the permanent magnet slots; and a plurality of magnetic conductive blocks corresponding to the plurality of permanent magnet slots, each of the magnetic conductive blocks being arranged on a side of the corresponding permanent magnet slot close to the rotor shaft in a radial direction, the magnetic conductive blocks being configured to move between a first position close to the permanent magnet slots and a second position away from the permanent magnet slots to adjust a magnetic field distribution of the rotor assembly, and the magnetic conductive blocks being configured to move to or close to the first position when a speed of the mobile device is greater than a first speed to improve efficiency of the permanent magnet synchronous motor in a high speed working condition.

[0027] In a twelfth aspect, a mobile device is provided, comprising the permanent magnet synchronous motor of the eleventh aspect.

[0028] In a thirteenth aspect, a permanent magnet synchronous motor is provided, comprising a stator assembly and a rotor assembly, the rotor assembly comprising: a rotor shaft; a rotor core sleeved on the rotor shaft and having a plurality of permanent magnet slots uniformly distributed in a circumferential direction; a plurality of permanent magnets arranged in the permanent magnet slots; and a plurality of magnetic conductive blocks corresponding to the plurality of permanent magnet slots, each of the magnetic conductive blocks being arranged on a side of the corresponding permanent magnet slot close to the rotor shaft in a radial direction, the magnetic conductive blocks being configured to move between a first position close to the permanent magnet slots and a second position away from the permanent magnet slots to adjust a magnetic field distribution of the rotor assembly, and the magnetic conductive blocks being further configured to move from the second position to a position close to the first position to reduce a back electromotive force of the stator assembly when the back electromotive force of the stator assembly increases.

[0029] In a fourteenth aspect, a vehicle is provided, comprising the permanent magnet synchronous motor of the thirteenth aspect. BRIEF DESCRIPTION OF DRAWINGS

[0030] FIG. 1 is a structural schematic diagram of a rotor assembly according to an embodiment of the present application;

[0031] FIG. 2 is a simulation result of a magnetic field distribution of the rotor assembly in FIG. 1;

[0032] FIG. 3 is a structural schematic diagram of a rotor assembly according to another embodiment of the present application;

[0033] FIG. 4 is a simulation result of a magnetic field distribution of the rotor assembly in FIG. 3;

[0034] FIG. 5 is a schematic diagram of a fixed magnetic bridge in a rotor core according to an embodiment of the present application;

[0035] FIG. 6 is a schematic diagram of a fixed magnetic bridge in a rotor core according to another embodiment of the present application;

[0036] FIG. 7 is a structural schematic diagram of a rotor assembly in the related art;

[0037] FIG. 8 is a magnetic field distribution simulation result of the rotor assembly in FIG. 7;

[0038] FIG. 9 is a structural schematic diagram of a rotor core provided by an embodiment of the present application;

[0039] FIG. 10 is a structural schematic diagram of a rotor assembly provided by another embodiment of the present application;

[0040] FIG. 11 is a structural schematic diagram of the rotor assembly when a pin shaft is located in a first movement section of a cam groove;

[0041] FIG. 12 is a structural schematic diagram of the rotor assembly when the pin shaft is located in a first rest section of the cam groove;

[0042] FIG. 13 is a structural schematic diagram of the rotor assembly when the pin shaft is located in a second movement section of the cam groove.

[0043] FIG. 14 is a structural schematic diagram of a rotor assembly provided by yet another embodiment of the present application;

[0044] FIG. 15 is an A-A cross-sectional view of FIG. 14;

[0045] FIG. 16 is a B-B cross-sectional view of FIG. 15;

[0046] FIG. 17 is a structural schematic diagram of a moving unit provided by another embodiment of the present application;

[0047] FIG. 18 is a C-C cross-sectional view of FIG. 17;

[0048] FIG. 19 is a structural schematic diagram of a rotor assembly provided by an embodiment of the present application;

[0049] FIG. 20 is a D-D cross-sectional view of FIG. 19;

[0050] FIG. 21 is a structural schematic diagram of a moving unit provided by another embodiment of the present application;

[0051] FIG. 22 is a transmission schematic diagram of FIG. 21;

[0052] FIG. 23 is a structural schematic diagram of a first fixing seat and a second fixing seat provided by an embodiment of the present application;

[0053] FIG. 24 is a structural schematic diagram of a first fixing seat and a second fixing seat provided by another embodiment of the present application.

[0054] FIG. 25 is a structural schematic diagram of a rotor assembly provided by yet another embodiment of the present application;

[0055] FIG. 26 is a structural schematic diagram of the rotor assembly when a magnetic conductive block is located in a second position;

[0056] Fig. 27 is an E-E sectional view of Fig. 25;

[0057] Fig. 28 is a structural schematic diagram of a retaining mechanism according to another embodiment of the application;

[0058] Fig. 29 is a structural schematic diagram of a retaining mechanism according to still another embodiment of the application. DETAILED DESCRIPTION

[0059] Embodiments of the application provide a rotor assembly, a permanent magnet synchronous motor, a traction system and a vehicle. The technical solutions of the application will be further described below in the embodiments and in conjunction with the drawings. In the description, identical or similar reference numerals indicate identical or similar components. The following description of the embodiments of the application is intended to explain the general inventive concept of the application, and should not be construed as a limitation of the application.

[0060] Before introducing the technical solutions provided by the embodiments of the application, the permanent magnet synchronous motor in the related art and problems thereof will be described in detail.

[0061] A permanent magnet synchronous motor (PMSM) mainly comprises a stator assembly, a rotor assembly and a motor shell, etc. The stator assembly comprises a stator core and a stator winding wound thereon. When three-phase current is supplied to the stator winding, a rotating magnetic field is generated, which interacts with a permanent magnetic field excited by permanent magnets in the rotor assembly to provide torque for the rotor assembly.

[0062] Permanent magnet motors have a series of advantages such as small size, low weight and high power density. They can output large torque at low speed and have excellent low-speed performance. In addition, China is rich in rare earth mineral resources, and the manufacturing cost of permanent magnet synchronous motors is relatively low. This makes the permanent magnet synchronous motor widely used in electric vehicles, high-speed railways, urban rail transit, aerospace and industrial production, etc.

[0063] However, the permanent magnet synchronous motor also faces some practical problems in engineering applications, which will be described in detail below.

[0064] The air gap magnetic field of the permanent magnet synchronous motor is difficult to adjust, resulting in a narrow constant power region. In order to solve this problem, the method of field weakening control (also known as field regulation) can be used to expand the speed.

[0065] The motor field regulation method in the related art includes AC pulse field regulation, DC pulse field regulation and mechanical field regulation.

[0066] The AC pulse magnetism adjusting mode is to apply a direct-axis magnetizing / demagnetizing pulse current through the stator armature winding to realize magnetizing / demagnetizing of the permanent magnet, so as to adjust the air gap magnetic flux density and expand the operation range of the motor.

[0067] The DC pulse magnetism adjusting mode is to realize magnetizing / demagnetizing of the permanent magnet through a DC magnetism adjusting winding specially arranged on the motor stator or rotor.

[0068] The mechanical magnetism adjusting mode is to change the magnetic field distribution of the main magnetic circuit of the motor through an additional mechanical mechanism in the stator or rotor, so as to adjust the air gap magnetic flux density. For example, a plurality of slots are arranged in the rotor core, and permanent magnets with the same polarity are arranged at both ends of the slots, wherein the outer sides are fixed and the inner sides are linked with the magnetic conductive blocks to slide. When the motor speed increases, the permanent magnets not fixed will move to the direction close to the air gap under the action of the centrifugal force, so that the magnetic resistance of the main magnetic pole leakage circuit is reduced, the leakage magnetic flux is increased, and the magnetic flux passing through the air gap is reduced, so as to reduce the air gap magnetic flux density when the motor runs at high speed.

[0069] In the above-mentioned various modes, the field weakening current in the DC or AC pulse magnetism adjusting mode will cause high copper loss, which will reduce the efficiency of the permanent magnet synchronous motor when running at high speed. At the same time, this mode also needs to add additional components in the circuit part, which will increase the cost. The existing mechanical magnetism adjusting mode is a passive adjustment, that is, the field weakening capability cannot be actively controlled, and the field weakening capability of this method is limited and cannot achieve the expected effect.

[0070] In addition, in some special scenarios, for example, for the application in high-speed railway and other rail transit vehicles, when the motor winding short circuit fault occurs when the train runs at high speed, the motor stator three-phase winding is cut off and the rotor is idling under the action of external force. In this case, the winding coil continuously cuts the permanent magnet magnetic field, generating a large induced electromotive force, which causes a large circulating current in the shorted coil. On the one hand, this current will cause the winding to heat up or even catch fire, and on the other hand, the large short-circuit current will generate a pulsating magnetic field, which will interact with the rotor permanent magnet magnetic field to cause the rotor to vibrate, directly endangering the safe operation of the vehicle. At this time, if the permanent magnet magnetic flux of the rotor can be adjusted to 0 or close to 0, there will be no induced electromotive force in the three-phase winding coil, which can ensure the safety of the train.

[0071] Therefore, how to further adjust the rotor permanent magnet magnetic field of the permanent magnet synchronous motor has become a problem to be solved.

[0072] In view of the above problems, the embodiments of the present application provide a rotor assembly, a permanent magnet synchronous motor, a traction system and a vehicle. The technical solutions of the embodiments of the present application will be described in detail below with reference to the drawings.

[0073] FIG. 1 is a schematic structural diagram of a rotor assembly 10 according to an embodiment of the present application, which includes a rotor core 11, permanent magnets 12, and magnetic conductive blocks 13.

[0074] The rotor core 11 has a plurality of permanent magnet grooves 111 distributed along a circumferential direction.

[0075] The circumferential direction in the present application refers to a circumferential direction around an axial direction of the rotor core 11, and the axial direction refers to a direction of a central axis of the rotor core 11.

[0076] The permanent magnets 12 are arranged in the permanent magnet grooves 111.

[0077] The permanent magnet in the present application refers to a magnet capable of maintaining magnetism for a long time, such as natural magnetite (ferromagnetic ore) and artificial magnetic steel (for example, iron-nickel-cobalt magnetic steel, neodymium-iron-boron magnetic steel, and samarium-cobalt magnetic steel, etc.).

[0078] The magnetic conductive blocks 13 are arranged corresponding to the permanent magnet grooves 111, and each magnetic conductive block 13 is arranged along a radial direction on a side of the corresponding permanent magnet groove 111 close to a rotating shaft.

[0079] The magnetic conductive blocks 13 are configured to move between a first position close to the permanent magnet grooves 111 and a second position away from the permanent magnet grooves 111, so as to adjust a magnetic field distribution of the rotor assembly 10.

[0080] According to the principle of minimum magnetic resistance, the magnetic field will be distributed along a direction with smaller magnetic resistance, and the magnetic resistance of the magnetic conductive blocks 13 is much smaller than that of air. Therefore, in the rotor assembly 10, the magnetic lines of the permanent magnet field generated by the permanent magnets 12 will preferentially pass through the magnetic conductive blocks; when the position of the magnetic conductive blocks 13 changes, the magnetic field distribution in the rotor assembly 10 changes accordingly.

[0081] More specifically, when the magnetic conductive blocks 13 are located at the first position close to the permanent magnet grooves 111, the rotor permanent magnet field will gather to the position of the magnetic conductive blocks 13; or in other words, in the case that the magnetic conductive blocks are located at the first position close to the permanent magnet grooves 111, the rotor permanent magnet field does not pass through the air gap of the rotor assembly; or in other words, in the case that the magnetic conductive blocks are located at the first position close to the permanent magnet grooves 111, the air gap magnetic field of the rotor assembly is 0.

[0082] When the magnetic conductive blocks 13 are located at the second position away from the permanent magnet grooves 111, an air gap is formed between the magnetic conductive blocks 13 and the rotor core 11, and the magnetic resistance at this position is larger. The permanent magnet field of the permanent magnets 12 will preferentially pass through the rotor core with smaller magnetic resistance, and at this time, the magnetic field strength of the air gap magnetic field of the rotor assembly 10 is larger.

[0083] In some embodiments, the magnetic conductive block 13 is made of a material with high saturation magnetic induction, for example, 1J22 alloy, which has a saturation magnetic induction of 2.4T or above, much higher than that of air and silicon steel sheet. The magnetic conductive block made of a material with high saturation magnetic induction can meet the requirement of adjusting the magnetic flux of the rotor assembly to the maximum in the minimum size.

[0084] In some embodiments, when the magnetic conductive block 13 is in the first position, the end of the magnetic conductive block 13 close to the permanent magnet slot 111 abuts against the rotor core 11 in the radial direction.

[0085] That is, in the above state, the end face of the magnetic conductive block 13 is completely coincident with the side wall of the rotor core 11, and there is no gap between the magnetic conductive block 13 and the rotor core 11; if there is a gap, it will cause the magnetic resistance here to be larger, and it cannot be ensured that the permanent magnet magnetic field of the permanent magnet can be more concentrated in the magnetic conductive block.

[0086] In some embodiments, as shown in FIGS. 1 and 3, the permanent magnet slot 111 includes a first permanent magnet slot 1111 and a second permanent magnet slot 1112. The first permanent magnet slot 1111 and the second permanent magnet slot 1112 are symmetrically arranged about the D-axis center line. The plurality of first permanent magnet slots 1111 and second permanent magnet slots 1112 in the rotor assembly 10 are alternately arranged and radially arranged.

[0087] The first permanent magnet slot 1111 and the second permanent magnet slot 1112 form a first opening at the end close to the rotation axis, and the width of the magnetic conductive block 13 in the direction perpendicular to the radial direction is not less than the width of the first opening, so that the end face of the magnetic conductive block 13 close to the end of the permanent magnet slot 111 can completely cover the first opening, so that when the magnetic conductive block 13 is in the first position, the proportion of the material with high permeability in the core is larger, which is more conducive to guiding the magnetic field into the magnetic conductive block 13.

[0088] In some embodiments, the rotor core 11 has a recess 112 recessed toward the direction close to the permanent magnet slot 111, the recess 112 is arranged corresponding to the permanent magnet slot 111 and located on the side of the permanent magnet slot 111 close to the rotation axis.

[0089] Correspondingly, the end of the magnetic conductive block 13 close to the permanent magnet slot 111 has a protrusion, which matches the shape of the recess 112, and when the magnetic conductive block 13 is in the first position, the protrusion extends into the recess 112.

[0090] By providing a protrusion on the magnetic conductive block 13 extending toward the direction of the permanent magnet slot, when the magnetic conductive block moves to the first position, the permanent magnet magnetic field of the permanent magnet can be preferentially concentrated in the magnetic conductive block with smaller magnetic resistance, thereby avoiding the core part from reaching the saturation state first.

[0091] In some embodiments, as shown in FIG. 1, the first end of the magnetic conducting block 13 has a first end surface 131 and a second end surface 132, which form an included angle, and the included angle is towards the end close to the permanent magnet slot 111. In other words, the first end surface 131 and the second end surface 132 form a protruding part of the magnetic conducting block 13. The protruding part is provided in a V shape, which is simple in structure and easy to process.

[0092] It should be noted that the distance of the first end of the magnetic conducting block 13 extending outward along the direction close to the permanent magnet slot 111 should not be too long. For example, when the included angle of the first end surface 131 and the second end surface 132 shown in FIG. 1 is small, since the recessed part 112 matches the shape of the magnetic conducting block 13, an air gap will be formed in the permanent magnet slot 111, and when the magnetic conducting block 13 is in the second position, the air gap will form a magnetic barrier, affecting the adjustment of the permanent magnet field of the rotor assembly.

[0093] Therefore, in the embodiments of the present application, the included angle between the first end surface 131 and the second end surface 132 is obtuse.

[0094] Of course, the shape of the protruding part is not limited to the form shown in FIG. 1, and can also be a circular arc, a rectangle, and a polygon (such as a trapezoid), etc.

[0095] In some embodiments, the rotor core 11 has a plurality of sliding grooves 113 corresponding to the plurality of permanent magnet slots 111. Each sliding groove 113 is arranged along the radial direction, and the first end of each sliding groove 113 along the radial direction is close to the permanent magnet slot 111, and the second end is spaced apart from the rotation shaft of the rotor assembly 10. The magnetic conducting block 13 can move in the sliding groove 113 to move between the first position and the second position.

[0096] It should be understood that the radial direction here can be understood as the direction perpendicular to the aforementioned axial direction.

[0097] The first end of the sliding groove 113 has a recessed area 1131, which matches the shape of the protruding part of the magnetic conducting block 13. In other words, the recessed area 1131 forms the recessed part 112.

[0098] Of course, the shape of the first end of the sliding groove 113 is not limited to the form shown in FIG. 1, and the first end of the sliding groove 113 can also be a circular arc, a rectangle, and a polygon (such as a trapezoid), etc. as long as the shape of the magnetic conducting block 13 can match it.

[0099] The technical solutions are further described below with reference to Figs. 1-4. In Fig. 1, the plurality of magnetic-conducting blocks 13 are all located at a second position away from the permanent magnet slot, and the magnetic field distribution at this time is shown in Fig. 2. In Fig. 3, the plurality of magnetic-conducting blocks are all located at a first position close to the permanent magnet slot, and the magnetic field distribution at this time is shown in Fig. 4.

[0100] It should be noted that, for ease of understanding, only a part of the rotor assembly 10 and the corresponding stator assembly is shown in Figs. 2 and 4. In Figs. 2 and 4, the closer the color is to orange, the higher the magnetic field strength, and the closer the color is to blue, the lower the magnetic field strength.

[0101] When the magnetic-conducting blocks 13 are located at the second position as shown in Fig. 1, it can be seen from Fig. 2 that the magnetic field strength in the air gap between the magnetic-conducting blocks 13 and the rotor core is close to 0, and the magnetic flux lines of the permanent magnet field of the permanent magnet mostly extend outward, and the point with the maximum magnetic field strength is located in the air gap of the rotor assembly, especially at the end of the core of the stator assembly.

[0102] When the magnetic-conducting blocks 13 are located at the first position as shown in Fig. 3, it can be seen from Fig. 4 that the magnetic flux lines of the permanent magnet field of the permanent magnet mostly extend to the position of the magnetic-conducting blocks 13, that is, the permanent magnet field is gathered to the side away from the air gap, and the magnetic field strength at the position of the magnetic-conducting blocks is the maximum, while the magnetic field strength in the air gap is 0.

[0103] It can be understood that Figs. 1-4 only show the magnetic field distribution when the magnetic-conducting blocks 13 are at the two extreme positions of the first position and the second position, and in actual application, the magnetic-conducting blocks 13 can be arranged at any position between the first position and the second position according to the requirements of a specific scene. When the magnetic-conducting blocks 13 are at different positions, the rotor assembly can present different air gap magnetic fields.

[0104] According to the above technical solutions provided in the embodiments of the present application, by arranging the magnetic-conducting blocks corresponding to the plurality of permanent magnets in the rotor assembly, and adjusting the positions of the magnetic-conducting blocks to generate different leakage magnetic fields, the permanent magnet field is adjusted, the permanent magnet synchronous motor has a wider speed regulation range, the power factor of the permanent magnet motor at high speed is improved, and the motor iron loss can be eliminated or reduced. When the magnetic-conducting blocks are moved to the end close to the permanent magnet, the rotor permanent magnet field can be gathered in the rotor assembly, which can avoid a large circulating current when the motor is being towed, and ensure the safety of the traction system when the stator winding is short-circuited.

[0105] When the application is applied to the permanent magnet traction system of a railway train, the magnetic field can be completely prevented from passing through the air gap by adjusting the position of the magnetic conductive block, so that no current is induced in the stator winding in the case of inter-turn short circuit fault, ensuring the fault-oriented safety of the permanent magnet traction motor. When the vehicle is inert, the generation of iron loss of the motor can also be avoided by eliminating the magnetic field. When the vehicle is running at high speed, the leakage magnetic flux at the magnetic conductive block can be adjusted by adjusting the position of the magnetic conductive block, so as to adjust the main magnetic field, increase the speed regulation range of the motor, and make the motor have higher power factor and efficiency under high-speed working condition. The technical scheme can completely solve the pain points of the permanent magnet traction system, improve the efficiency, solve the safety problem, and has great significance for the safe operation of the next generation of permanent magnet traction system.

[0106] In some embodiments, as shown in FIGS. 1 and 3, the first permanent magnet slot 1111 and the second permanent magnet slot 1112 near the end of the rotating shaft are smaller than or equal to the arc angle away from the end of the rotating shaft. In other words, the first permanent magnet slot 1111 and the second permanent magnet slot 1112 in the same permanent magnet slot 111 are arranged in a V shape.

[0107] It should be noted that the first permanent magnet slot 1111 and the second permanent magnet slot 1112 near the end of the rotating shaft are not connected to each other. The rotor structure with V-shaped permanent magnet slots has the advantages of small leakage magnetic coefficient, no need to use magnetic isolation measures on the rotating shaft, easy to control the pole arc coefficient, high mechanical strength of the rotor lamination, and the rotor is not easy to deform after installation, which can be applied in many fields such as rail transit and electric vehicles.

[0108] In some embodiments, the first position is located at the end of the first permanent magnet slot 1111 and the second permanent magnet slot 1112 near the rotating shaft. Or, the first end of the sliding groove 113 is close to the closed end of the V-shaped permanent magnet slot. In this way, not only the depth of the magnetic field can be adjusted, but also the rotational inertia of the rotor can be increased, and the mechanical strength can be maintained.

[0109] In some embodiments, as shown in FIGS. 5 and 6, the first permanent magnet slot 1111 is provided with a first magnetic isolation slot 1111a and a second magnetic isolation slot 1111b, and the second permanent magnet slot 1112 is provided with a third magnetic isolation slot 1112a and a fourth magnetic isolation slot 1112b. The purpose of the plurality of magnetic isolation slots is to avoid the leakage of the two magnetic poles of the permanent magnet arranged in the permanent magnet slot.

[0110] In some embodiments, the second magnetic isolation slot 1111b and the fourth magnetic isolation slot 1112b are in communication with the sliding groove 113, and the structure of the rotor assembly can refer to FIGS. 1 and 3.

[0111] In some embodiments, as shown in FIGS. 5 and 6, the rotor core 11 further has outer magnetic bridges 114 corresponding to the permanent magnet slots 111. More specifically, the outer magnetic bridges 114 include a first outer magnetic bridge 114a and a second outer magnetic bridge 114b. The first outer magnetic bridge 114a is arranged between the first magnetic isolation slot 1111a and the outer edge of the rotor assembly 10, and the second outer magnetic bridge 114b is arranged between the third magnetic isolation slot 1112a and the outer edge of the rotor assembly 10. It should be noted that FIGS. 5 and 6 respectively show the cases where the magnetic conductive blocks 13 are located at both ends of the sliding slot 113.

[0112] In some embodiments, continuing to refer to FIGS. 5 and 6, the rotor core 11 further has inner magnetic bridges 115 corresponding to the permanent magnet slots 111. More specifically, the inner magnetic bridges 115 include a first inner magnetic bridge 115a and a second inner magnetic bridge 115b. The first inner magnetic bridge 115a is arranged between the sliding slot 113 and the second magnetic isolation slot 1111b, and the second inner magnetic bridge 115b is arranged between the sliding slot 113 and the fourth magnetic isolation slot 1112b.

[0113] The main purpose of arranging the first outer magnetic bridge 114a and the second outer magnetic bridge 114b is to increase the structural strength of the rotor core 11. However, the existence of the outer magnetic bridges will cause the leakage of the rotor permanent magnet, which will increase the consumption of the permanent magnet.

[0114] The following will be described in conjunction with a pair of examples. FIGS. 7 and 8 show the simulation diagrams of a rotor assembly and the magnetic field distribution thereof in the related art.

[0115] As shown in FIG. 7, the rotor assembly 30 has a first permanent magnet slot 31a and a second permanent magnet slot 31b. The first permanent magnet slot 31a has a first magnetic isolation slot 32a and a second magnetic isolation slot 32b arranged at both ends thereof, and the second permanent magnet slot 31b has a third magnetic isolation slot 33a and a fourth magnetic isolation slot 33b arranged at both ends thereof. The first magnetic isolation slot 32a and the third magnetic isolation slot 33a have a first outer magnetic bridge 34a and a second outer magnetic bridge 34b arranged between the edges of the rotor assembly. The rotor assembly 30 further has a magnetic isolation hole 35, and a first inner magnetic bridge 36a and a second inner magnetic bridge 36b arranged between the magnetic isolation hole 35 and the second magnetic isolation slot 32b and the fourth magnetic isolation slot 33b, respectively.

[0116] As can be seen from the simulation result of FIG. 8, the permanent magnet first saturates the outer magnetic bridge 35 and the inner magnetic bridge 36. The magnetic field strength near the magnetic bridges is relatively large, and part of the permanent magnet does not participate in the establishment of the main magnetic flux, which is an invalid part.

[0117] In view of the above problems, in order to eliminate the adverse effects of the magnetic bridge on the magnetic field distribution, in some embodiments, the first magnetic isolation slot 1111a and the third magnetic isolation slot 1112a penetrate the rotor core 11 along the radial direction; that is, in this embodiment, there is no outer magnetic bridge on the rotor core 11, and the structure of the rotor assembly can refer to FIG. 1 and FIG. 3.

[0118] In the foregoing embodiments, since the permanent magnet slot 111 penetrates the outer edge of the rotor core 11 through the magnetic isolation slot, when the rotor assembly 10 rotates at high speed, the rotor core and the permanent magnet will both bear a large centrifugal force.

[0119] Therefore, in order to ensure the structural strength of the rotor assembly 10, in some embodiments, as shown in FIG. 1 and FIG. 3, the rotor assembly 10 is further provided with a rotor sheath 15, which is sleeved on the outside of the rotor core 11, for improving the strength of the rotor assembly.

[0120] In some embodiments, the rotor sheath 15 is made of carbon fiber or non-magnetic alloy material, which can meet the strength requirements and will not affect the magnetic field distribution of the rotor assembly. By reducing the outer magnetic bridge, the air gap width can be increased, which is also beneficial to reducing the magnetic leakage on the side of the magnetic conductive block.

[0121] In some embodiments, as shown in FIG. 9, the rotor core 11 includes a core shaft core 11a, a D-axis core 11b and a Q-axis core 11c. The core shaft core 11a is a shaft sleeve close to the axis of the rotor core 11, the D-axis core 11b is located between the first permanent magnet slot 1111 and the second permanent magnet slot 1112, and the Q-axis core 11c is located between two adjacent permanent magnet slots 111.

[0122] It should be noted that the dashed line in FIG. 9 is for the convenience of describing and understanding each part in the rotor core 11, and does not mean that the core shaft core 11a, the D-axis core 11b and the Q-axis core 11c are separated from each other.

[0123] In some embodiments, the core shaft core 11a, the D-axis core 11b and the Q-axis core 11c are integrally formed. The integrally formed manner is simple in process and can reduce the processing cost of the rotor core.

[0124] In some embodiments, the core shaft core 11a, the D-axis core 11b and the Q-axis core 11c are of a combined structure and can be made of different materials.

[0125] The D-axis core 11b is made of silicon steel material, amorphous material or nanocrystalline material, which has small iron loss and can reduce the heating of the rotor core.

[0126] The Q-axis core 11c is made of silicon steel material, amorphous material or nanocrystalline material. The orientation direction of the silicon steel material is axial and has high magnetic permeability; the nanocrystalline material also has high magnetic permeability, which can reduce the heat generation of the rotor assembly while realizing the miniaturization and light weight of the motor.

[0127] In some embodiments, the core shaft core 11a and the Q-axis core 11c are integrally formed, which can be made of the same material, thereby reducing the processing procedure.

[0128] In some embodiments, the core shaft core 11a and the Q-axis core 11c can be connected through dovetail structure; specifically, the core shaft core 11a is a sleeve structure, and the outer surface of the sleeve structure is provided with a plurality of dovetail grooves in the axial direction; the Q-axis core 11c is provided with a dovetail-shaped protrusion at one end close to the core shaft core 11a, and the protrusion is inserted into the dovetail groove of the core shaft core 11a, thereby combining the Q-axis core 11c and the core shaft core 11a. Compared with the integrated forming mode of the core shaft and the Q-axis core, the technical solution can greatly improve the utilization rate of the material and save the manufacturing cost.

[0129] In some embodiments, the rotor assembly 10 further comprises a driving mechanism to drive the magnetic block 13 to move in the sliding groove 113.

[0130] The embodiment of the present application provides a permanent magnet synchronous motor, which comprises a rotor assembly and a stator assembly, wherein the rotor assembly is the rotor assembly described in any of the foregoing embodiments.

[0131] The permanent magnet synchronous motor can be applied in various fields such as aviation, national defense, industrial and agricultural production and daily life. Specifically, the motor can be applied to industrial driving devices, automation equipment, fans, pumps, compressors, machine tools, robots, and vehicles.

[0132] The vehicle can include a road vehicle, an air vehicle, a water vehicle, an industrial device, an agricultural device, or an entertainment device, etc.

[0133] For example, the water vehicle can be a hovercraft, a motorboat, a motorboat, a fishing boat, a cruise ship, a sailboat, a yacht, etc.

[0134] The air vehicle can be an airplane, and the road vehicle can be a vehicle.

[0135] In some embodiments, the vehicle is a vehicle. For example, the vehicle is one of a commercial vehicle, a passenger vehicle, a motorcycle, a flying vehicle, and a train.

[0136] In some embodiments, the vehicle is an industrial vehicle or an engineering vehicle. For example, the vehicle is one of a forklift, a trailer, a tractor, an excavator, a bulldozer, and a crane.

[0137] In some embodiments, the vehicle can be an electric vehicle or a fuel vehicle. Exemplarily, the vehicle is one of a pure electric vehicle (PEV / BEV), a hybrid electric vehicle (HEV), a range extended electric vehicle (REEV), and a plug-in hybrid electric vehicle (PHEV).

[0138] In some embodiments, the vehicle can also be an agricultural device (such as a mower, a harvester, etc.), a recreational device, a toy vehicle, etc.

[0139] In some embodiments, the vehicle can also be a high-speed railway train, a motor train unit train, a city rail transit vehicle, etc.

[0140] The application also provides a permanent magnet synchronous motor, a power system, and a city rail transit vehicle.

[0141] The total energy consumption of the city rail transit system can be divided into station operation energy consumption and train operation energy consumption. The station operation energy consumption includes the energy consumption of station lighting, air conditioning, elevators, etc., and this part of energy consumption value is relatively fixed and accounts for a small proportion of the overall energy consumption. The vehicle energy consumption is mainly the traction energy consumption in the train operation process. As an important link in the traction system that undertakes energy conversion, the traction motor improves the efficiency in various working conditions, which is an important measure to reduce the train energy consumption.

[0142] The distance between stations of the city rail system is usually short, and the running process of the vehicle between two stations includes three intervals of acceleration, coasting, and deceleration. The vehicle starts from static state and accelerates to the highest speed when leaving the station, and then slides for a distance, and starts to brake until stopping when approaching the next station. Alternatively, when the interval distance is long, the vehicle can experience a second acceleration interval and a second coasting interval after the coasting interval, that is, the vehicle accelerates twice after coasting. That is, the power system of this type of vehicle needs to be started and stopped frequently, and the coasting working condition is more.

[0143] From the demand of the city rail vehicle for the traction electric drive system, in order to improve the operation efficiency, the city rail transit vehicle needs to have as large as possible acceleration / deceleration in the acceleration and deceleration intervals, which requires a large torque in the starting and braking stages.

[0144] Currently, asynchronous induction motor is widely used as the driving motor of urban rail transit vehicle. The asynchronous induction motor provides excitation magnetic field by rotor winding, and generates rotating magnetic field when three-phase current is applied to stator winding, the rotating magnetic field interacts with the excitation magnetic field of the rotor winding to provide torque for the rotor. In the above process, there is a large loss in the process of forming the excitation magnetic field in the rotor winding.

[0145] The permanent magnet synchronous motor uses permanent magnet for excitation, and the rotor magnetic field is completely generated by permanent magnet material, and there is no additional energy consumption in the process of generating excitation magnetic field. When it is applied to urban rail transit vehicle, the loss of motor can be greatly reduced.

[0146] However, there is a long coasting section during the operation of urban rail transit vehicle, and the rotor will idle under the action of vehicle inertia in the coasting section. For asynchronous motor, as long as the excitation current of the stator and the rotor is disconnected, the stator and the rotor magnetic field will disappear, thereby disconnecting the coupling between the stator and the rotor. For permanent magnet synchronous motor, during the process of rotor idling, the permanent magnet magnetic field of the rotor does not disappear, and the magnetic field will be coupled with the stator core, which will cause excessive iron loss in the stator core, thereby affecting the performance of the motor, which is not conducive to reducing the energy consumption of the whole power system.

[0147] The permanent magnet synchronous motor applied to the power system of urban rail transit vehicle provided by the embodiment of the present application is dedicated to solving the problem that the energy saving effect of urban rail transit vehicle is not good due to high iron loss under light load or no load working condition.

[0148] The urban rail transit vehicle mentioned here can include subway train, light rail train, monorail train and tramcar, etc.

[0149] The permanent magnet synchronous motor includes a rotor assembly and a stator assembly. The structure of the rotor assembly can be seen from FIG. 1. The rotor assembly 11 includes a rotor core 11, a permanent magnet 12 and a magnetic conducting block 13. The specific structure of the rotor assembly 11 has been described in detail above, and will not be repeated here.

[0150] In the embodiment of the present application, the magnetic conducting block 13 is configured to be located at a first position close to the permanent magnet slot 111 when the vehicle is in coasting working condition, so as to reduce the iron loss of the permanent magnet synchronous motor 1 under the coasting working condition.

[0151] According to the principle of minimum magnetic resistance, the magnetic field will be distributed along the direction of smaller magnetic resistance. When the magnetic conducting block 13 is located at the first position close to the permanent magnet slot 111, because its magnetic resistance is much smaller than air, the rotor permanent magnet magnetic field will preferentially pass through the magnetic conducting block 13, so that the magnetic field is gathered in the magnetic conducting block 13, which reduces the air gap magnetic field strength of the rotor assembly 10.

[0152] When the permanent magnetic field of the rotor assembly 10 is reduced, the coupling between the rotor assembly 10 and the stator assembly 20 is weakened in the condition that the motor is being dragged, thereby reducing the iron loss of the motor.

[0153] The magnetic conducting block 13 in the embodiment of the present application is further configured to be located at a second position away from the permanent magnet slot 111 when the vehicle is in the traction condition. In this case, an air gap is formed between the magnetic conducting block 13 and the rotor core 11, the magnetic resistance of the position is relatively large, the permanent magnetic field of the permanent magnet 12 will preferentially pass through the rotor core 11 with relatively small magnetic resistance, at this time, the air gap magnetic field strength of the rotor assembly 10 can be improved. The magnetic coupling between the rotor permanent magnetic field and the stator winding magnetic field is relatively strong, so that the permanent magnet synchronous motor can output a larger torque, thereby ensuring the traction performance of the motor.

[0154] When the magnetic conducting block 13 is located at the second position as shown in FIG. 1, it can be seen from FIG. 2 that the magnetic field strength in the air gap between the magnetic conducting block 13 and the rotor core 11 is close to 0, the magnetic induction lines of the permanent magnetic field of the permanent magnet 12 mostly extend outward, and the point with the maximum magnetic field strength is located in the air gap of the rotor assembly 10, especially at the end of the core of the stator assembly 20. At this time, strong coupling is generated between the three-phase winding magnetic field and the rotor permanent magnetic field, so that the rotor assembly 10 can output a larger power, at this time, the motor has better traction performance.

[0155] When the magnetic conducting block 13 is located at the first position as shown in FIG. 3, it can be seen in combination with FIG. 4 that the magnetic induction lines of the permanent magnetic field of the permanent magnet 12 mostly extend to the position of the magnetic conducting block 13, that is, the permanent magnetic field is gathered to the side away from the air gap, the magnetic field strength at the position of the magnetic conducting block 13 is the largest, and the magnetic field strength in the air gap is 0. When the motor is dragged to make the rotor assembly rotate freely, the interaction between the air gap magnetic field and the stator core 20 is weakened due to the small air gap magnetic field strength at this time, thereby reducing the iron loss of the motor.

[0156] That is, according to the above technical solution provided by the embodiment of the present application, by adjusting the position of the magnetic conducting block in the rotor assembly of the permanent magnet synchronous motor according to the running condition of the urban rail transit vehicle, the motor iron loss can be reduced in the vehicle idling condition, and energy is saved; at the same time, the traction performance of the motor can be ensured in the traction condition.

[0157] For the existing permanent magnet synchronous motor, the air gap magnetic field strength is determined by the permanent magnet in the rotor assembly, which is relatively difficult to adjust, which will lead to a narrow constant power range, especially in the case of high speed, the efficiency of the motor will be significantly reduced. When applied to urban rail transit vehicles, the traction performance will be significantly reduced at high traction speed.

[0158] Therefore, in some embodiments of the present application, the magnetic conducting block 13 is further configured to move between the first position and the second position to adjust the magnetic field distribution of the rotor assembly 10 and increase the speed range of the permanent magnet synchronous motor 1 when the speed of the vehicle is greater than the first speed threshold.

[0159] The foregoing FIGS. 1-4 only show the magnetic field distribution of the magnetic conducting block 13 at the two extreme positions of the first position and the second position, which respectively correspond to the minimum magnetic field and the maximum magnetic field. The rotor assembly 10 can present an air gap magnetic field of different intensity when the magnetic conducting block 13 is arranged at any position between the first position and the second position.

[0160] The first speed threshold can be the speed of the vehicle when the permanent magnet synchronous motor operates at rated speed, for example, can be 60km / h, 80km / h or 100km / h, etc. The embodiments of the present application do not make specific limitations thereon, and can be determined according to the specific parameters of the driving and transmission mechanism of the traction system of the vehicle.

[0161] When the speed of the vehicle exceeds the first speed threshold, the permanent magnet synchronous motor will exceed the constant power range, resulting in a decline in traction performance. In this case, the position of the magnetic conducting block 13 can be adjusted, for example, moved from the second position to the direction close to the first position, changing the magnetic field distribution of the rotor assembly 10 to achieve the purpose of field weakening and speed expansion.

[0162] In some embodiments, when the position of the magnetic conducting block is adjusted, the specific position of the magnetic conducting block can be determined according to the speed of the vehicle. For example, the difference between the current speed of the vehicle and the first speed threshold can be determined. The greater the difference, the farther the magnetic conducting block is from the second position, and vice versa. The smaller the difference, the closer the magnetic conducting block is to the second position.

[0163] According to the technical solution, the movable magnetic conducting block is used to realize field weakening and speed expansion in a high-speed scenario, which can avoid the problems of increased cost and energy consumption caused by the technical solution of applying demagnetizing current for field weakening and speed expansion in the related art.

[0164] The embodiments of the present application also provide a power system applied to a city rail transit vehicle and used for providing power for the city rail transit vehicle. The power system is also referred to as an electric drive system of the city rail transit vehicle, and the power system comprises the permanent magnet synchronous motor as described in any of the foregoing embodiments.

[0165] The embodiments of the present application also provide a city rail transit vehicle comprising the permanent magnet synchronous motor or the power system as described in any of the foregoing embodiments. The city rail transit vehicle can be a subway train, a light rail train, a monorail train, a tram, etc.

[0166] The embodiment of the present application also provides a permanent magnet synchronous traction motor, a traction system and a locomotive. The technical problems faced by the permanent magnet traction technology in the field of locomotives are solved.

[0167] The locomotive is an important tool for railway transportation, and is used for traction or pushing of railway vehicles. The traction quality of the locomotive can usually reach several or tens of times of the self weight. The technical scheme provided by the embodiment of the present application is mainly applied to the traction locomotive of a freight train. For the freight train, the first problem to be considered is heavy load, that is, the maximum traction force (continuous traction force) needs to be exerted. On this basis, the locomotive needs to be able to pass through a slope at a high speed (that is, continuous speed), and the maximum speed of the locomotive must also be ensured, which is a performance of the rapid transportation capacity of the locomotive.

[0168] According to the difference of the power device, the locomotive can be divided into a diesel locomotive and an electric locomotive.

[0169] The diesel locomotive usually takes a diesel engine or the like as a power source. The diesel engine is operated to drive a generator to operate. The electric energy generated by the generator is transmitted to an electric motor to convert the electric energy into mechanical energy. The mechanical energy is transmitted to a locomotive driving wheel through a transmission system such as a speed change gear to thereby traction the vehicle. The diesel locomotive is also called an electric transmission diesel locomotive. The maximum power of the diesel locomotive is limited by the power of the diesel engine, which limits the traction capacity of the diesel locomotive.

[0170] The electric locomotive has fast starting and accelerating and strong climbing ability, and is not affected by severe cold. The electric locomotive does not discharge exhaust gas during operation, and becomes the main force of modern railway transportation.

[0171] For the electric locomotive, the electric transmission system composed of a traction motor and a control system thereof is the most critical component, and plays a decisive role in the advantages and disadvantages of the whole vehicle performance. The development of the electric transmission system of the electric locomotive has experienced a direct current transmission system, an asynchronous transmission system and a permanent magnet synchronous transmission system.

[0172] The direct current transmission system is widely used in early locomotives. With the development of control technology, the speed regulation performance of the speed regulation system of the alternating current asynchronous motor is improved by adopting the magnetic field oriented vector control technology. In addition, the asynchronous motor itself has advantages, and is widely used in the electric transmission system of the locomotive and becomes the current mainstream.

[0173] The permanent magnet synchronous motor does not need rotor excitation current in operation, and has a series of advantages such as small size, low weight and high power density. The permanent magnet synchronous motor can output large torque at low speed, has excellent low speed performance, and the rare earth mineral resources are abundant in China. The manufacturing cost of the permanent magnet synchronous motor is low, so the application of the electric transmission system based on the permanent magnet synchronous motor in the locomotive becomes one of the research hotspots in recent years.

[0174] As described above, the locomotive has the characteristics of low speed and heavy load, and its continuous running speed is generally 20-25 km / h, and the maximum running speed is generally not more than 120 km / h, which requires the electric drive system to be able to output constant power in a wide speed range.

[0175] For the permanent magnet synchronous motor, it can provide larger torque at low speed to ensure the low speed traction performance of the locomotive; but the speed range of this type of motor is small, and in high speed working condition, the working range of the permanent magnet synchronous motor may exceed its constant power range, which will result in the inability to provide the required traction force in high speed working condition, resulting in limited traction performance.

[0176] The permanent magnet synchronous traction motor provided by the embodiments of the present application can ensure constant power output in a wide speed range and ensure the traction performance of the locomotive.

[0177] The permanent magnet synchronous motor includes a stator assembly and a rotor assembly, and the rotor assembly includes a rotating shaft, a rotor core, a permanent magnet, and a magnetic conducting block. Referring to FIG. 1 and the description above, the specific structure of the rotor assembly will not be described again here.

[0178] Referring to FIG. 1, in this embodiment, the magnetic conducting block 13 is configured to move between a first position close to the permanent magnet slot 111 and a second position away from the permanent magnet slot 111 according to the running speed of the locomotive, to adjust the magnetic field distribution of the rotor assembly 10, so that the permanent magnet synchronous traction motor 1 outputs constant power when driving the locomotive to work in its running speed range.

[0179] The saturation magnetic induction intensity of the magnetic conducting block 13 is much larger than that of air and silicon steel sheet, and its magnetic resistance is small, so the rotor permanent magnet field will preferentially pass through the magnetic conducting block 13, and the magnetic field near the magnetic conducting block 13 is concentrated. When the magnetic conducting block 13 moves between the first position and the second position, it will have different effects on the distribution of the rotor permanent magnet field. Therefore, in the technical solution of the present application, the position of the magnetic conducting block can be adjusted according to the running speed of the locomotive, so as to change the magnetic field distribution of the rotor assembly, so that the permanent magnet synchronous traction motor can output constant power.

[0180] When the magnetic conducting block 13 is located at the second position as shown in FIG. 1, it can be seen from FIG. 2 that the magnetic field intensity in the air gap between the magnetic conducting block 13 and the rotor core 11 is close to 0, and the magnetic induction lines of the permanent magnet field of the permanent magnet 12 are mostly directed outward, and the point with the maximum magnetic field intensity is located in the air gap of the rotor assembly 10, especially at the end of the core of the stator assembly 20. At this time, the stator three-phase winding magnetic field is strongly coupled with the rotor permanent magnet field, and the rotor assembly 10 can output larger torque, which is suitable for low speed working conditions such as climbing or starting.

[0181] When the magnetic conductive block 13 is located at the first position as shown in FIG. 3, it can be seen in combination with FIG. 4 that the magnetic induction lines of the permanent magnetic field of the permanent magnet 12 mostly extend to the position of the magnetic conductive block 13, that is, the permanent magnetic field is gathered to the side away from the air gap, the magnetic field strength at the position of the magnetic conductive block 13 is the largest, and the magnetic field strength in the air gap is close to 0. In this case, the magnetic conductive block 13 is used to realize the field weakening of the rotor assembly, at this time the permanent magnet synchronous traction motor 1 can keep the output power basically constant while rotating at high speed, which is suitable for the aforementioned high-speed running working condition.

[0182] It should be noted that the above only describes the case when the magnetic conductive block 13 is at the two extreme positions of the first position and the second position. When the magnetic conductive block 13 is at different positions between the first position and the second position, the rotor assembly 10 will present different magnetic field distributions; the closer to the first position, the smaller the permanent magnetic field strength of the rotor assembly 10, and the closer to the second position, the larger the permanent magnetic field strength. In actual application, the position of the magnetic conductive block 13 can be determined according to the speed of the locomotive, so that the traction motor can output constant power in the entire speed range.

[0183] According to the above technical solutions provided in the present application, by arranging a movable magnetic conductive block in the rotor assembly of the permanent magnet synchronous traction motor, during the running of the locomotive, the position of the magnetic conductive block is adjusted according to the running speed of the locomotive to change the magnetic field distribution of the rotor assembly, so that the permanent magnet synchronous traction motor can output constant power in the running speed range of the locomotive, and the traction capacity and running efficiency of the locomotive are improved.

[0184] In some embodiments, the magnetic conductive block 13 is further configured to: when the speed of the locomotive is greater than the first speed, the magnetic conductive block is located at or close to the first position, so as to reduce the air gap magnetic field strength of the rotor assembly and improve the rotating speed of the permanent magnet synchronous traction motor. The first speed is related to the rated rotating speed of the permanent magnet synchronous traction motor.

[0185] The above first speed can be the speed of the locomotive when the permanent magnet synchronous traction motor runs at the rated rotating speed, for example, it can be 100km / h or 120km / h, etc., and the present embodiment does not make specific limitation thereon, which can be determined according to the specific parameters of the driving and transmission mechanism of the traction system of the locomotive. The smaller the first speed, the narrower the demand for the constant power range of the permanent magnet synchronous traction motor. When the speed of the locomotive exceeds the first speed, the traction motor can work outside the constant power range, which can cause the traction performance of the locomotive to decrease, in this case, the magnetic conductive block can be moved to the direction close to the first position to change the magnetic field distribution of the rotor assembly, so as to achieve the purpose of field weakening and speed expansion.

[0186] In the technical solution, under high-speed working condition, the movement of the magnetic conducting block is used to realize the field weakening of the permanent magnet synchronous traction motor, so that the permanent magnet synchronous traction motor can maintain constant power output at high speed, and the problems of cost and energy consumption increase caused by the existing technical solution of applying demagnetizing current for field weakening are avoided.

[0187] The embodiment of the application further provides a traction system applied to a locomotive, which can be an electric transmission diesel locomotive or an electric locomotive, and the traction system comprises the permanent magnet synchronous traction motor as described above.

[0188] The embodiment of the application further provides a locomotive comprising the permanent magnet synchronous traction motor or the traction system as described above.

[0189] The locomotive can be, for example, an electric transmission diesel locomotive, which is driven by an internal combustion engine to drive a generator, and the generator generates electric energy to drive the synchronous traction motor or the traction system to drive the vehicle. Alternatively, the locomotive can also be an electric locomotive, which can store electric energy by means of a battery or receive electric energy from a catenary by means of a pantograph, and the permanent magnet synchronous traction motor or the traction system converts the received electric energy into mechanical energy to drive the vehicle.

[0190] The embodiment of the application further provides a power system and a train, which are dedicated to solving the safety problem of the permanent magnet synchronous motor in the power system of a railway vehicle, especially a high-speed railway vehicle, when an inter-turn short circuit fault occurs.

[0191] When an inter-turn short circuit fault occurs in part or all of the permanent magnet synchronous motors in the power system of a train, the train cannot be immediately stopped due to the huge inertia of the train. Especially for high-speed train sets and high-speed railway trains, when the running speed is 350km / h, the braking distance is about 6500m; when the speed reaches 400km / h, the braking distance will increase to 9100m.

[0192] During the above braking process, the motor in the power system of the train works in the reverse traction working condition, and the rotor in the motor is dragged to rotate at high speed. Since the rotor assembly of the permanent magnet synchronous motor is excited by a permanent magnet, the permanent magnet magnetic field of the rotor does not disappear when the motor is idling; that is, the electromagnetic coupling between the stator and the rotor assembly has not been eliminated, and the stator winding cuts the permanent magnet magnetic field to generate a large circulating current in the stator.

[0193] The circulating current in the stator winding can cause the winding to heat up, resulting in a sharp rise in temperature in the motor housing, which can cause the permanent magnet to demagnetize at high temperature. At the same time, the temperature is too high to cause the winding to catch fire, and if the fire spreads in the high-speed moving EMU train, it will cause huge loss of life and property. The huge short-circuit current in the stator winding can generate a pulsating magnetic field, which can interact with the rotor permanent magnet magnetic field, causing the motor to vibrate strongly, which can drive the car body to vibrate, which can threaten the safe operation of the high-speed EMU train. In addition, even if the vehicle can be quickly stopped when a fault occurs, it also needs to be towed back to the garage by other vehicles, and in this process, the inter-turn short circuit will still be further expanded, and there is still a risk of causing a fire.

[0194] The power system provided by the embodiments of the present application can reduce the probability of occurrence of safety accidents when the inter-turn short circuit fault of the permanent magnet synchronous motor occurs, and realize fault-oriented safety. The power system is applied to a train, which can be any one of a general-speed train, a fast train, an EMU train and a high-speed train, and the embodiments of the present application do not make specific limitation on this.

[0195] The power system includes a plurality of permanent magnet synchronous motors for driving the train to run, and the permanent magnet synchronous motor includes a stator assembly and a rotor assembly. The rotor assembly includes a rotating shaft, a rotor core, a permanent magnet and a magnetic conducting block. The structure of the rotor assembly can be referred to FIG. 1, which will not be described here.

[0196] The magnetic conducting block 13 is configured to move between a first position close to the permanent magnet slot 111 and a second position away from the permanent magnet slot 111 to adjust the magnetic field distribution of the rotor assembly 10. When the magnetic conducting block 13 is located at the first position close to the permanent magnet slot 111, the rotor permanent magnet magnetic field will gather to the position of the magnetic conducting block 13; or in other words, in the case that the magnetic conducting block is located at the first position close to the permanent magnet slot 111, the rotor permanent magnet magnetic field does not pass through the air gap of the rotor assembly; or in other words, in the case that the magnetic conducting block is located at the first position close to the permanent magnet slot 111, the air gap magnetic field of the rotor assembly is 0. When the magnetic conducting block 13 is located at the second position away from the permanent magnet slot 111, an air gap is formed between the magnetic conducting block 13 and the rotor core 11, and the position has a large magnetic resistance. The permanent magnet magnetic field of the permanent magnet 12 will preferentially pass through the rotor core with a small magnetic resistance, and at this time, the air gap magnetic field of the rotor assembly 10 has a large magnetic field strength.

[0197] The power system in the embodiments of the present application is configured to: when an inter-turn short circuit fault occurs in a target permanent magnet synchronous motor in the plurality of permanent magnet synchronous motors, switch the magnetic conducting block in the target synchronous motor to the first position to short-circuit the main magnetic flux of the target permanent magnet synchronous motor, so that the target permanent magnet synchronous motor is taken out of service.

[0198] In the power system of this application embodiment, there are multiple permanent magnet synchronous motors. The target permanent magnet synchronous motor is one of the motors that has experienced a short-turn fault. The number of such motors can be one or more, and this application embodiment does not limit the number of such motors.

[0199] The target permanent magnet synchronous motor can be determined based on the current or temperature of the stator windings of multiple permanent magnet synchronous motors in the power system. For example, during the operation of the power system, the current of the stator windings of these multiple motors is monitored. When the winding current of one or more motors increases abnormally, it can be determined that there is a risk of failure, and this motor can be identified as the target permanent magnet synchronous motor. As described above, when the magnetic block 13 is in the first position, the rotor permanent magnet magnetic field does not pass through the air gap of the rotor assembly, meaning that the air gap magnetic field strength of the rotor assembly is close to 0 under these conditions. When the rotor assembly 10 is reverse-driven and idling, due to the extremely low air gap magnetic field strength, the rotor assembly 10 will not generate magnetic coupling with the stator windings. Therefore, there are no risks such as circulating current, heating, or vibration, ensuring the safety of the target permanent magnet synchronous motor.

[0200] Based on the above technical means, in response to the requirement that the rotor magnetic field of the target motor that has malfunctioned needs to be completely eliminated during train operation, the magnetic flux of the target motor's rotor assembly is weakened by a movable magnetic guide block in the rotor assembly, so that the target motor is taken out of service, avoiding any impact on train safety, and thus achieving fault-guided safety.

[0201] This application also provides a train, including the power system as described above.

[0202] This application also provides a permanent magnet synchronous motor and mobile equipment. This technical solution is applied to the field of mobile equipment such as vehicles to solve the following technical problems in this field.

[0203] The rotor magnetic field of a permanent magnet synchronous motor is generated by permanent magnets in the rotor assembly. When the vehicle is operating at high speed, the stator windings cut the rotor magnetic field, generating a back electromotive force (EMF). When the back EMF increases, the motor will lose its ability to accelerate. If you want to continue to increase the speed, you need to perform field weakening control on the rotor permanent magnet magnetic field.

[0204] Currently, the most common field weakening method is to apply a direct-axis field weakening current, which reduces the back electromotive force in the stator windings and increases the motor speed. During field weakening control, the energy supplied to the permanent magnet synchronous motor is divided into two parts: one part is used to provide torque, and the other part is used for field weakening. This increases energy consumption and reduces efficiency at high speeds.

[0205] The technical solution provided in this application can reduce the loss of permanent magnet synchronous motors and improve their efficiency.

[0206] The permanent magnet synchronous motor provided by the embodiments of the present application is applied to a mobile device, and is used to provide power for the mobile device. The mobile device can be an electrically powered vehicle using the permanent magnet synchronous motor as a power source, including a land vehicle, an air vehicle, a water vehicle, an industrial device, an agricultural device, or an entertainment device, etc. For example, the water vehicle can be a hovercraft, a motorboat, a speedboat, a fishing boat, a cruise ship, a sailboat, a yacht, or the like, the air vehicle can be an airplane, and the land vehicle can be a vehicle.

[0207] In some embodiments, the vehicle is a vehicle. For example, the vehicle is one of a commercial vehicle, a passenger vehicle, a motorcycle, a flying vehicle, and a train.

[0208] In some embodiments, the vehicle is an industrial vehicle or an engineering vehicle. For example, the vehicle is one of a forklift, a trailer, a tractor, an excavator, a bulldozer, a crane, and an electric wheel mining truck.

[0209] In some embodiments, the vehicle can be an electric vehicle or a hybrid vehicle. For example, the vehicle is one of a pure electric vehicle (PEV / BEV), a hybrid electric vehicle (HEV), a range extended electric vehicle (REEV), and a plug-in hybrid electric vehicle (PHEV).

[0210] In some embodiments, the vehicle can also be an agricultural device (such as a mower, a harvester, etc.), a recreational device, a toy vehicle, etc.

[0211] The permanent magnet synchronous motor provided by the embodiments of the present application includes a stator assembly and a rotor assembly. The structure of the rotor assembly can be referred to FIG. 1 and the foregoing description, which will not be repeated here.

[0212] The magnetic conducting block 13 is configured to move to the first position or close to the first position when the speed of the mobile device is greater than the first speed, so as to improve the efficiency of the permanent magnet synchronous motor in the high speed working condition.

[0213] It should be understood that the first speed is related to the inherent parameters of the permanent magnet synchronous motor applied to the mobile device. For example, the first speed can be determined according to the maximum speed of the permanent magnet synchronous motor in the constant power region; or the first speed can also be determined according to the rated speed of the permanent magnet synchronous motor. When the speed of the vehicle is greater than the first speed, it is considered to be in a high speed working condition.

[0214] It should be further noted that the first speed is usually different for different types of mobile equipment. For example, for mine trucks, in order to ensure a large traction capacity, the reduction ratio of the transmission mechanism is usually high, the moving speed is usually slow, and the corresponding first speed is low, for example, it can be 15 km / h or 20 km / h, etc. For example, for electric vehicles, the moving speed is usually fast, and the first speed can be, for example, 100 km / h, 120 km / h or higher.

[0215] When the speed of the mobile equipment is high, as mentioned above, the way of applying demagnetizing current is less efficient. In the technical solution of the present application, the permanent magnet magnetic field of the rotor assembly can be adjusted by using the movable magnetic conductive block described above, and the purpose of field weakening can also be achieved. Since this method does not need to provide demagnetizing current, it saves part of the energy, thereby improving the energy efficiency of the permanent magnet synchronous motor.

[0216] As shown in FIG. 2, when the magnetic conductive block 13 is located at the first position, the magnetic lines of the permanent magnet magnetic field of the permanent magnet 12 mostly extend to the position of the magnetic conductive block 13, that is, the permanent magnet magnetic field is concentrated to the side away from the air gap, the magnetic field strength at the position of the magnetic conductive block 13 is the largest, and the magnetic field strength in the air gap is 0.

[0217] The structure of the permanent magnet synchronous motor when the magnetic conductive block 13 is located at the second position and the corresponding magnetic field distribution are shown in FIG. 3 and FIG. 4, respectively.

[0218] As can be seen from FIG. 3 and FIG. 4, when the magnetic conductive block 13 is located at the second position, the magnetic lines of the permanent magnet magnetic field of the permanent magnet 12 mostly extend to the outside, and the point with the largest magnetic field strength is located in the air gap of the rotor assembly 10, especially at the end of the core of the stator assembly 20. When the mobile equipment is running normally, the magnetic conductive block 13 can be kept at this position to make the permanent magnet synchronous motor exert the maximum capacity to output constant power to ensure the low-speed traction capacity and acceleration capacity of the vehicle.

[0219] It can also be understood that FIGS. 1-4 only show the magnetic field distribution when the magnetic conductive block 13 is located at the two extreme positions of the first position and the second position. In fact, the magnetic conductive block 13 can move between the two positions, and since the magnetic resistance of the magnetic conductive block 13 is much smaller than air, the rotor permanent magnet magnetic field will move in the direction of smaller magnetic resistance, so when the position of the magnetic conductive block 13 changes, the magnetic field distribution of the rotor assembly 10 changes accordingly. The closer the magnetic conductive block 13 is to the first position, the smaller the air gap magnetic field strength, and vice versa, the closer the magnetic conductive block 13 is to the second position, the larger the magnetic field strength. Therefore, in the technical solution of the embodiment of the present application, in order to improve the efficiency at high speed, the magnetic conductive block 13 can be moved to the first position or close to the first position.

[0220] The embodiment of the present application also provides a mobile equipment comprising the permanent magnet synchronous motor as described above.

[0221] The embodiment of the present application also provides a permanent magnet synchronous motor and a vehicle, which are used to solve the safety problem caused by the high back electromotive force of the permanent magnet synchronous motor in high-speed rotation.

[0222] The rare earth permanent magnet with high magnetic field strength is embedded in the rotor assembly of the permanent magnet synchronous motor. When the rotor rotates, the magnetic flux through the coil of the stator winding will change greatly. According to the law of electromagnetic induction, the stator winding coil will generate an electromotive force due to the change of the magnetic field, and the size of the electromotive force is proportional to the number of turns of the stator winding coil, the air gap magnetic field strength and the rotational speed of the rotor. For the permanent magnet synchronous motor, the number of turns of the coil and the air gap magnetic field strength are usually constant values, so the higher the motor speed, the greater the back electromotive force.

[0223] In order to ensure the performance of the permanent magnet synchronous motor at high speed, a feasible method to reduce the back electromotive force in the related art is to weaken the magnetism of the rotor by applying a d-axis demagnetizing current, so as to reduce the air gap magnetic field strength, thereby ensuring the performance of the motor at the current high speed, and also improving the speed range of the motor operation.

[0224] However, the method of increasing the demagnetizing current will cause high copper loss, which reduces the efficiency of the motor in high-speed operation. At the same time, this method also needs to add additional components in the circuit part, which increases the cost of the whole machine.

[0225] The permanent magnet synchronous motor and the vehicle provided by the embodiment of the present application can inhibit the back electromotive force of the permanent magnet synchronous motor under high-speed working condition, and expand the operation range of the permanent magnet synchronous motor. The technical scheme is described in detail as follows.

[0226] The permanent magnet synchronous motor comprises a stator assembly and a rotor assembly, and the rotor assembly comprises a rotating shaft, a rotor core, a permanent magnet and a magnetic conducting block. The structure of the rotor assembly is shown in FIG. 1 and described above, and will not be described here again.

[0227] In the embodiment of the present application, the magnetic conducting block 13 is configured to move from the second position to the direction close to the first position when the back electromotive force of the stator assembly 20 increases, so as to reduce the back electromotive force of the stator assembly 20.

[0228] When the back electromotive force increases, the magnetic conducting block 13 is moved to the direction close to the first position, which reduces the magnetic field strength of the rotor assembly 10. Under the condition that the other conditions are the same, the back electromotive force will be reduced with the reduction of the magnetic field strength.

[0229] It should be noted that in the technical solutions of the embodiments of the present application, the increase of the back EMF of the stator assembly 10 can be determined by monitoring the voltage or current of the stator winding. Specifically, during the operation of the motor, the voltage or current of the stator winding is monitored in real time, and the greater the change, the greater the back EMF. According to the above technical solutions, by arranging the movable magnetic conducting block in the rotor assembly of the permanent magnet synchronous motor, when the back EMF of the stator increases under high-speed working conditions, the magnetic field intensity of the rotor assembly is reduced by the movement of the magnetic conducting block, which can effectively suppress the back EMF of the stator assembly, so that the motor has higher power factor and efficiency under high-speed working conditions, and the operating range of the motor is increased.

[0230] In some embodiments, when the magnetic conducting block 13 is located at the first position, the back EMF of the stator assembly 20 is 0.

[0231] As mentioned above, when the magnetic conducting block 13 is at the first position, the magnetic flux of the rotor assembly 10 can be completely short-circuited, so that the magnetic intensity of the rotor assembly 10 is 0, at this time the magnetic coupling between the rotor assembly 10 and the stator assembly 20 is completely released, so that the back EMF of the stator assembly 20 is 0. Therefore, there is no risk of circulating current, heating and vibration, etc.

[0232] The embodiments of the present application also provide a vehicle comprising the permanent magnet synchronous motor as described above.

[0233] FIG. 10 is a schematic structural diagram of a rotor assembly 200 provided by another embodiment of the present application.

[0234] As shown in FIG. 10, the rotor assembly 200 in the embodiments of the present application comprises a rotor core 201, permanent magnets 202, magnetic conducting blocks 203 and a cam mechanism 204.

[0235] The rotor core 201 has a plurality of permanent magnet grooves 2011 uniformly distributed along the circumferential direction. It should be noted that the circumferential direction here refers to the circumferential direction around the axial direction of the rotor core 201, and the axial direction refers to the direction of the central axis of the rotor assembly 200.

[0236] The permanent magnets 202 are arranged in the permanent magnet grooves 2011. The permanent magnets 202 in the embodiments of the present application refer to magnets that can maintain magnetism for a long time, such as natural magnetite (ferromagnetic ore) and artificial magnetic steel (such as iron-nickel-cobalt magnetic steel, neodymium-iron-boron magnetic steel, etc.).

[0237] The magnetic conducting blocks 203 are arranged corresponding to the permanent magnet grooves 2011, and each magnetic conducting block 203 is arranged on the side of the corresponding permanent magnet groove 2011 close to the shaft 205 along the radial direction.

[0238] The cam mechanism 204 comprises a plurality of pin shafts 2041 and a cam disc 2042.

[0239] The plurality of pin shafts 2041 are respectively connected with the plurality of magnetic conductive blocks 203. The pin shafts 2041 and the magnetic conductive blocks 203 can be fixedly connected through welding, riveting, bonding or threaded connection, and the connecting mode is not limited in the embodiment.

[0240] The cam disc 2042 has a plurality of cam grooves 20421 corresponding to the plurality of pin shafts 2041. The plurality of cam grooves 20421 are equidistantly arranged along the rotation center of the cam disc 2042.

[0241] The pin shafts 2041 are movably connected in the cam grooves 20421. The side walls of the cam grooves 20421 can limit the pin shafts 2041, and limit the movement of the pin shafts 2041 to sliding in the cam grooves 2042 along the extension direction of the cam grooves 20421.

[0242] The cam disc 2042 can rotate in the circumferential direction, so that the pin shafts 2041 drive the magnetic conductive blocks 203 to move in the radial direction between a first position close to the permanent magnet slot 2011 and a second position away from the permanent magnet slot 2011, to adjust the magnetic field distribution of the rotor assembly.

[0243] According to the principle of minimum magnetic resistance, the magnetic field will be distributed along the direction of smaller magnetic resistance. The magnetic resistance of the magnetic conductive block 203 is much smaller than air. Therefore, in the rotor assembly 200, the magnetic lines of the permanent magnet magnetic field generated by the permanent magnet 202 will preferentially pass through the magnetic conductive block 203; when the magnetic conductive block 203 moves under the action of the cam mechanism 204, the magnetic field distribution in the rotor assembly 200 changes.

[0244] More specifically, when the magnetic conductive block 203 moves to the first position close to the permanent magnet slot 2011, the rotor permanent magnet magnetic field will gather to the position of the magnetic conductive block 203; or in the case that the magnetic conductive block 203 is located at the first position close to the permanent magnet slot 2011, the rotor permanent magnet magnetic field does not pass through the air gap of the rotor assembly 200; or in the case that the magnetic conductive block 203 is located at the first position close to the permanent magnet slot 2011, the air gap magnetic field of the rotor assembly 200 is 0.

[0245] When the magnetic conductive block 203 moves to the second position away from the permanent magnet slot 2011, an air gap is formed between the magnetic conductive block 203 and the rotor core, and the magnetic resistance at this position is larger. The permanent magnet magnetic field of the permanent magnet 202 will preferentially pass through the rotor core 201 with smaller magnetic resistance, and at this time the air gap magnetic field of the rotor assembly 200 has a larger magnetic field strength.

[0246] When the magnetic conducting block 203 is in different positions between the first position and the second position, the width of the air gap between the magnetic conducting block 203 and the rotor core 201 is different, thereby causing the magnetic conducting block 203 to have different influences on the air gap magnetic field of the rotor assembly 200; that is, by adjusting the position of the magnetic conducting block 203, the permanent magnetic field of the rotor assembly 200 can be adjusted.

[0247] According to the above technical means, the cam mechanism is arranged in the rotor assembly, and the cam groove determines different positions of the pin, which changes the topology of the rotor magnetic field when the magnetic conducting block is driven to move radially in the rotor core, thereby achieving the purpose of adjusting the air gap magnetic field strength of the rotor assembly.

[0248] In some embodiments, the magnetic conducting block 203 is made of a material with high saturation magnetic induction, for example, 1J22 alloy, 2J10 alloy, 1J85 alloy, etc., which has a saturation magnetic induction of 2.4T or above, much larger than the saturation magnetic induction of air and silicon steel sheet. The magnetic conducting block 203 made of a material with high saturation magnetic induction can meet the requirement of adjusting the magnetic flux of the rotor assembly 200 to the maximum in the minimum size.

[0249] In some embodiments, the cam groove 20421 includes at least one movement section and at least one rest section, when the pin shaft 2041 moves in the movement section, the magnetic conducting block 203 moves radially towards or away from the permanent magnet slot 2011; when the pin shaft 2041 moves in the rest section, the magnetic conducting block 203 remains radially static.

[0250] FIGS. 11-13 are partial structural schematic diagrams of the rotor assembly provided by the embodiments of the present application, which show the distribution of the magnetic conducting block when the pin shaft 2041 is located at different positions of the cam groove 20421. The cam groove 20421 shown in FIGS. 11-13 has a first movement section 20421A, a second movement section 20421C, and a first rest section 20421B between the first movement section 20421A and the second movement section 20421C.

[0251] FIGS. 11-13 respectively show the case that the cam disc 2042 is rotated in the counterclockwise direction (indicated by the arrow in the figure) to a position where the pin shaft 2041 is located at the first movement section 20421A, the first rest section 20421B, and the second movement section 20421C, respectively.

[0252] As shown in FIG. 11, in the initial state, the pin shaft 2041 is located at one end of the cam groove 20421 away from the rotation shaft 205 of the rotor assembly 200, or in other words, the pin shaft 2041 is located at one end of the first movement section 20421A away from the first rest section 20421B, and at this time, the magnetic block 203 is located at the first position close to the permanent magnet groove 2011, and in this case, the air gap magnetic field strength of the rotor assembly 200 is the smallest.

[0253] When the cam disc 2042 is counterclockwise rotated to the state shown in FIG. 12, the pin shaft 2041 is located at the first rest section 20421B, and at this time, the magnetic block 203 is located at the intermediate position between the first position and the second position. In this state, if the cam disc 2042 is rotated within the first angle a as shown in FIG. 12, the radial position of the pin shaft 2041 and the magnetic block 203 connected with the pin shaft 2041 will not change, which at the same time means that in this case, the air gap magnetic field strength of the rotor assembly 200 remains constant. Meanwhile, when the pin shaft 2041 is located at the first rest section 20421B, the cam disc 2042 can be kept at this position without external driving force.

[0254] When the cam disc 2042 is continuously rotated in the direction shown in the drawing to the state shown in FIG. 13, the pin shaft 2041 is located at one end of the cam groove 20421 close to the rotation shaft 205, or in other words, the pin shaft 2041 is located at one end of the second movement section 20421C away from the first rest section 20421B. In this case, the magnetic block 203 is moved to the second position away from the permanent magnet groove 2011, and at this time, the air gap magnetic field strength of the rotor assembly 200 is the largest.

[0255] According to the above technical means, the rest section is arranged in the cam groove, when the pin shaft is located at the rest section, the cam mechanism can keep the external force without external force, and the overall energy consumption of the rotor assembly can be reduced.

[0256] In some embodiments, continuing to refer to FIG. 12, in order to make the radial position of the pin shaft 2041 not change when the pin shaft 2041 is moved in the rest section, the generatrix of the rest section (for example, the first rest section 20421B in FIG. 12) is arranged as a circular arc, and the center of the circular arc coincides with the rotation center of the cam disc 2042.

[0257] In some embodiments, the cam groove 20421 can include a plurality of rest sections, and the diameters of the circular arcs where the generatrices of the plurality of rest sections are located are different. When the pin shaft 2041 is located at different rest sections, the magnetic block 203 is located at different positions, and the air gap magnetic field strength of the rotor assembly 200 is different.

[0258] The embodiments of the present application do not limit the specific positions of the above-mentioned plurality of rest sections, and the rest sections can be arranged at any position in the cam groove, and the positions of the plurality of rest sections can be determined according to the requirement of the air gap magnetic field strength.

[0259] The number of the plurality of rest segments is not limited, and can be two or more. For example, three rest segments can be arranged in the cam groove, and correspond to 25%, 50% and 75% of the maximum magnetic field strength, respectively.

[0260] According to the above technical means, the plurality of rest segments are arranged in the cam groove, so that the magnetic conducting block can have a plurality of transient stable positions during movement, and the air gap magnetic field strength of the rotor assembly is constant at the positions. The technical scheme can facilitate the segmented control of the magnetic field strength.

[0261] In some embodiments, the rotor assembly 200 includes two cam mechanisms, which are the cam mechanism 204 in any of the above embodiments. The two cam mechanisms are arranged at the two ends of the magnetic conducting block 203 in the axial direction, and the cam plates 2042 in the two cam mechanisms rotate synchronously, so that the pin shafts 2041 at the two ends of the magnetic conducting block 203 can simultaneously drive the magnetic conducting block 203 to move.

[0262] According to the above technical means, the two cam mechanisms are arranged at the two ends of the magnetic conducting block in the axial direction, and the two cam mechanisms are used to drive the magnetic conducting block to move, which can avoid the inclination of the magnetic conducting block due to uneven force.

[0263] In some embodiments, the cam mechanism further includes a plurality of pull rods, which are arranged in the magnetic conducting block in the axial direction, and the pin shaft 2041 is arranged at at least one end of the pull rod in the axial direction.

[0264] According to the above technical means, the pull rod is arranged in the magnetic conducting block, and the pin shaft is arranged at the end of the pull rod, which can simplify the manufacturing and assembly process, reduce the amount of high-saturation magnetic induction material, and reduce the cost.

[0265] In some embodiments, the rotor assembly further includes a driving unit for driving the cam plate to rotate in the circumferential direction. The driving unit can be, for example, an electric motor or a hydraulic motor.

[0266] As an implementation manner, the driving unit can be an external rotor motor, which is arranged between the rotating shaft of the rotor assembly and the cam plate. Specifically, the stator of the external rotor motor is sleeved on the rotating shaft and fixedly connected with the rotating shaft, and the cam plate is sleeved on the rotor of the external rotor motor and rotates in the circumferential direction under the driving of the rotor.

[0267] In some embodiments, the rotor assembly further includes a connecting shaft arranged in the axial direction, which is used to connect the cam plates in the two cam mechanisms at the two ends of the magnetic conducting block, so that the two cam plates can rotate synchronously. The connecting shaft can be sleeved on the rotating shaft of the rotor assembly and can rotate relative to the rotating shaft.

[0268] According to the above technical means, the two cam plates are synchronously rotated by the connecting shaft, and the two cam mechanisms are synchronously moved by the same driving unit, so that the inclination of the magnetic block during movement is avoided.

[0269] In some embodiments, the rotor assembly 200 further comprises a sensor and a control unit.

[0270] The sensor is used to determine the position of the magnetic block 203. According to the different setting positions of the sensor, there are various methods to determine the position of the magnetic block 203.

[0271] As an implementation manner, the sensor can be a distance sensor, which can be arranged on one side of the magnetic block 203 in the radial direction, for example, on the side of the magnetic block 203 close to the rotating shaft 205, for measuring the distance between the end of the sensor and the end face of the magnetic block 203 close to the rotating shaft 205, and determining the position of the magnetic block 203 according to the distance.

[0272] As another implementation manner, the sensor can also be a sensor for measuring the rotation angle, such as a Hall sensor, which can be used to measure the rotation angle of the cam plate 2042, and determine the position of the magnetic block 203 according to the change amount of the rotation angle.

[0273] The control unit is connected with the sensor and the driving unit, and is used to determine the air gap magnetic field strength of the rotor assembly 200 according to the position of the magnetic block 203, and control the driving unit to drive the cam plate 2042 to rotate, so that the pin shaft 2041 drives the magnetic block 203 to adjust the position, so as to adjust the air gap magnetic field strength of the rotor assembly 200 to the target magnetic field strength value.

[0274] It should be understood that the position of the magnetic block 203 and the air gap magnetic field strength value usually have a one-to-one corresponding relationship, and when the position of the magnetic block 203 is adjusted according to the target magnetic field strength value, the target position of the magnetic block 203 can be determined according to the mapping relationship between the position of the magnetic block 203 and the magnetic field strength which is established in advance; then the target stroke of the driving unit is determined according to the deviation between the target position and the current position of the magnetic block 203; and the control signal is sent to the driving unit according to the target stroke of the driving unit, so as to move the magnetic block 203 to the target position.

[0275] According to the above technical means, the radial position of the magnetic block is detected by the sensor, and then the main magnetic field strength is determined, and the magnetic field strength of the rotor assembly is adjusted according to the main magnetic field strength, so that the magnetic field strength of the rotor assembly is measurable and the adjustment process is controllable.

[0276] FIG. 14 is a schematic structural view of a rotor assembly 300 provided by another embodiment of the application. FIG. 15 is a partial sectional view of FIG. 14, and part of the structure of the rotor assembly 300 is omitted in FIG. 15 for ease of description.

[0277] In combination with FIG. 14 and FIG. 15, the rotor assembly 300 in the embodiment of the present application comprises a rotor core 301, permanent magnets 302, magnetic conductive blocks 303, and moving units 304.

[0278] The rotor core 301 has a plurality of permanent magnet grooves 3011 uniformly distributed along the circumferential direction. It should be noted that the circumferential direction here refers to the circumferential direction around the axial direction of the rotor core 301, and the axial direction refers to the direction of the central axis of the rotor assembly 300.

[0279] In some embodiments, the permanent magnet grooves 3011 comprise first permanent magnet grooves 30111 and second permanent magnet grooves 30112. The first permanent magnet grooves 30111 and the second permanent magnet grooves 30112 are symmetrically arranged about the D-axis center line. The plurality of first permanent magnet grooves 30111 and the plurality of second permanent magnet grooves 30112 in the rotor assembly 300 are alternately arranged and radially arranged, i.e., the first permanent magnet grooves 30111 and the second permanent magnet grooves 30112 are arranged in a V shape.

[0280] Such a rotor structure with V-shaped permanent magnet grooves has the advantages of small magnetic leakage coefficient, no need to use magnetic isolation measures on the shaft, easy control of pole arc coefficient, high mechanical strength of rotor lamination, and no easy deformation of the rotor after installation, and can be applied in many fields such as rail transit and electric vehicles.

[0281] It should be further noted that the arrangement of the permanent magnet grooves in the rotor assembly provided by the embodiment of the present application is not limited to the above-mentioned V-shaped arrangement, and the arrangement of the permanent magnet grooves can be any one of radial type, tangential type, or mixed type.

[0282] The permanent magnets 302 are arranged in the permanent magnet grooves 3011. The permanent magnets 302 referred to in the embodiment of the present application refer to magnets that can maintain magnetism for a long time, such as natural magnetite (ferromagnetic ore) and artificial magnetic steel (such as iron-nickel-cobalt magnetic steel, neodymium-iron-boron magnetic steel, etc.).

[0283] The magnetic conductive blocks 303 are arranged corresponding to the permanent magnet grooves 3011, and each magnetic conductive block 303 is arranged along the radial direction on the side of the corresponding permanent magnet groove 3011 close to the shaft 305.

[0284] The plurality of moving units 304 are respectively connected with the plurality of magnetic conductive blocks 303, and are used to drive the magnetic conductive blocks 303 to move along the radial direction between a first position close to the permanent magnet grooves 3011 and a second position away from the permanent magnet grooves 3011, so as to adjust the magnetic field distribution of the rotor assembly 300.

[0285] According to the principle of minimum magnetic reluctance, the magnetic field will be distributed along the direction of smaller magnetic reluctance, and the magnetic reluctance of the magnetic conductive block 303 is much smaller than air. Therefore, in the rotor assembly 300, the magnetic flux lines of the permanent magnetic field generated by the permanent magnet 302 will preferentially pass through the magnetic conductive block 303; when the magnetic conductive block 303 moves under the action of the moving unit 304, the magnetic field distribution in the rotor assembly 300 changes accordingly.

[0286] More specifically, when the magnetic conductive block 303 moves to the first position close to the permanent magnet slot 3011, the rotor permanent magnetic field will gather to the position of the magnetic conductive block 303; or in other words, in the case that the magnetic conductive block 303 is located at the first position close to the permanent magnet slot 3011, the rotor permanent magnetic field does not pass through the air gap of the rotor assembly 300; or in other words, in the case that the magnetic conductive block 303 is located at the first position close to the permanent magnet slot 3011, the air gap magnetic field of the rotor assembly 300 is 0.

[0287] When the magnetic conductive block 303 moves to the second position away from the permanent magnet slot 3011, an air gap is formed between the magnetic conductive block 303 and the rotor core 301, and the magnetic reluctance at this position is larger. The permanent magnetic field of the permanent magnet 302 will preferentially pass through the rotor core 301 with smaller magnetic reluctance, and at this time, the air gap magnetic field of the rotor assembly 300 has a larger magnetic field strength.

[0288] When the magnetic conductive block 303 is at different positions between the first position and the second position, the width of the air gap between the magnetic conductive block 303 and the rotor core 301 is different, thereby causing the magnetic conductive block 303 to have different influences on the air gap magnetic field of the rotor assembly 300; that is, by adjusting the position of the magnetic conductive block 303, the permanent magnetic field of the rotor assembly 300 can be adjusted.

[0289] In some embodiments, the magnetic conductive block 303 is made of a material with high saturation magnetic induction, for example, 1J22 alloy, 2J10 alloy, 1J85 alloy, etc., which has a saturation magnetic induction of 2.4T or above, much larger than the saturation magnetic induction of air and silicon steel sheet. The magnetic conductive block 303 made of a material with high saturation magnetic induction can meet the requirement of adjusting the magnetic flux of the rotor assembly 300 to the maximum in the smallest size.

[0290] As shown in FIG. 15, the moving unit 304 includes a first moving unit 304A arranged at the first end of the magnetic conductive block 303 along the axial direction, which can be any end of the magnetic conductive block 303 along the axial direction, for example, in the perspective of FIG. 15, the first moving unit 304A is located at the left side of the magnetic conductive block 303 along the axial direction.

[0291] The first moving unit 304A comprises a first connecting rod 3041A and a first wedge-shaped slide plate 3042A, and the first connecting rod 3041A is fixedly connected with the magnetic conducting block 303. The connection mode between the first connecting rod 3041A and the magnetic conducting block 303 may, for example, be welding, riveting, bonding or threaded connection, and the specific mode is not limited in the embodiments of the present application.

[0292] The first wedge-shaped slide plate 3042A has a first guide groove 30421A inclined relative to the axial direction of the rotor assembly 300, and the end of the first connecting rod 3041A away from the magnetic conducting block 303 abuts against the first guide groove 30421A.

[0293] The end of the first connecting rod 3041A away from the magnetic conducting block 303 may be a plane matching the extension direction of the first guide groove 30421A, and the first wedge-shaped slide plate 3042A is configured to be movable along the axial direction of the rotor assembly 300. During the movement, the first guide groove 30421A interacts with the end of the first connecting rod 3041A, so that the first connecting rod 3041A and the magnetic conducting block 303 are guided to move along the radial direction.

[0294] According to the above technical means, the movement of the magnetic conducting block along the radial direction is converted into the movement of the first wedge-shaped slide plate along the axial direction by matching the inclined surface of the first connecting rod with the first wedge-shaped slide plate. By adjusting the axial position of the first wedge-shaped slide plate, the stepless adjustment of the air gap magnetic field strength of the rotor assembly is realized.

[0295] In some embodiments, the first connecting rod 3041A is made of a non-magnetic conducting material, which may be a non-magnetic conducting metal material or a non-metal material, and the specific mode is not limited in the embodiments of the present application.

[0296] FIG. 16 is a B-B sectional view of FIG. 15. As shown in FIG. 16, in some embodiments, the cross section of the first guide groove 30421A is T-shaped, and the end of the first connecting rod 3041A away from the magnetic conducting block 303 has a first T-shaped end head matching the cross-sectional shape of the first guide groove 30421A, which is embedded in the first guide groove 30421A to slide in the first guide groove 30421A.

[0297] According to the above technical means, the cross section of the first guide groove is set to be T-shaped, and the movement direction of the first connecting rod is constrained by the side wall of the guide groove, so that the guidance is more accurate.

[0298] In some embodiments, referring back to FIG. 15, the rotor assembly 300 further comprises a transmission screw rod 306 extending along the axial direction of the rotor assembly 300, and the transmission screw rod 306 is rotatably connected with the rotor core 301. The end of the transmission screw rod 306 close to the first moving unit 304A has a first external thread 3061 along the axial direction.

[0299] The first wedge-shaped slide plate 3042A has a first internal thread 1422A penetrating the first wedge-shaped slide plate 3042A in the axial direction on the side close to the rotating shaft 305, and the first internal thread 1422A is in threaded cooperation with the first external thread 3061, so that the first wedge-shaped slide plate 3042A moves in the axial direction when the transmission screw rod 306 rotates. The thread forms, pitches, and rotation directions of the first internal thread 1422A and the first external thread 3061 are the same.

[0300] According to the above technical means, the movement of the magnetic block is converted into the rotation of the first screw rod by the threaded transmission between the first wedge-shaped slide plate and the transmission screw rod, so that the radial position of the magnetic block can be adjusted steplessly, thereby adjusting the air gap magnetic field strength of the rotor assembly.

[0301] In some embodiments, the transmission screw rod 306 is made of a non-magnetic material, such as a non-magnetic metal.

[0302] According to the above technical means, the transmission screw rod is made of a non-magnetic material, which can avoid the adverse effects of the transmission screw rod arranged in the rotor core on the magnetic field distribution of the rotor assembly.

[0303] In some embodiments, as shown in FIG. 17, the moving unit 304 further includes a second moving unit 304B arranged at the second end of the magnetic block 303 in the axial direction, and the second moving unit 304B includes a second connecting rod 3041B and a second wedge-shaped slide plate 3042B.

[0304] The second connecting rod 3041B is connected with the magnetic block 303. The second connecting rod 3041B can be connected with the magnetic block 303 by welding, riveting, bonding, or threaded connection, and the embodiments of the present application do not make specific limitations on this.

[0305] The second wedge-shaped slide plate 3042B has a second guide groove 30421B inclined relative to the axial direction of the rotor assembly, and the end of the second connecting rod 3041B away from the magnetic block 303 abuts against the second guide groove 30421B.

[0306] The end of the second connecting rod 3041B away from the magnetic block 303 can be a plane matching the extension direction of the second guide groove 30421B, and the second wedge-shaped block is configured to move in the axial direction of the rotor assembly 300. During the movement, the second guide groove 30421B interacts with the end of the second connecting rod 3041B, so that the second connecting rod 3041B and the magnetic block 303 are guided to move in the radial direction.

[0307] The first guide slot 30421A and the second guide slot 30421B are symmetrical along a plane perpendicular to the rotor assembly 300. When the first wedge-shaped slide 3042A and the second wedge-shaped slide 3042B move towards or away from each other along the axial direction, the first connecting rod, the second connecting rod and the magnetic block 303 are guided to be close to the permanent magnet slot in the radial direction

[0308] According to the above technical means, the first moving unit and the second moving unit are symmetrically arranged on both sides of the magnetic block in the axial direction, and the common action can avoid uneven force on the magnetic block during movement.

[0309] In some embodiments, the second connecting rod 3041B is made of a non-magnetic material, which can be a non-magnetic metal material or a non-metal material, and the embodiments of the present application are not limited thereto.

[0310] In some embodiments, the first connecting rod 3041A in the first moving unit 304A and the second connecting rod 3041B in the second moving unit 304B can be an integrated structure, that is, the first connecting rod 3041A and the second connecting rod 3041B are the same connecting rod, which can be provided in the magnetic block 303.

[0311] Figure 18 is a C-C cross-sectional view of Figure 17. As shown in Figure 18, in some embodiments, the cross section of the second guide slot 30421B is T-shaped, and the end of the second connecting rod 3041B away from the magnetic block 303 has a second T-shaped end head matching the cross-sectional shape of the second guide slot 30421B. The second T-shaped end head is embedded with the second guide slot 30421B to slide in the second guide slot 30421B.

[0312] According to the above technical means, the cross section of the second guide slot is set to T-shaped, and the side wall of the guide slot is used to constrain the moving direction of the second connecting rod, so that the guidance is more accurate.

[0313] In some embodiments, referring to Figure 17, the end of the transmission screw rod 306 close to the second moving unit 304B has a second external thread 3062. The side of the second wedge-shaped slide 3042B close to the shaft 305 is provided with a second internal thread 30422B penetrating in the radial direction. The second internal thread 30422B is threadedly matched with the second external thread 3062. When the transmission screw rod 306 rotates, the second wedge-shaped slide 3042B and the first wedge-shaped slide 3042A are both moved in the axial direction.

[0314] According to the above technical means, by setting the threaded transmission between the transmission screw rod and the second wedge-shaped slide, when the transmission screw rod rotates, the first wedge-shaped slide and the second wedge-shaped slide of the two magnetic blocks can be driven to move synchronously, thereby driving the magnetic block to move in the radial direction, avoiding the magnetic block from tilting due to uneven force.

[0315] Continuing to refer to FIG. 17, when the transmission screw rod 306 rotates, the rotation directions of the first external thread 3061 and the second external thread 3062 arranged at the two ends of the transmission screw rod 306 in the axial direction are the same. If the rotation directions of the first external thread 3061 and the second external thread 3062 are the same, the first wedge-shaped sliding plate 3042A and the second wedge-shaped sliding plate 3042B will move synchronously in the same direction. In order to enable the magnetic conductive block 303 to move radially, it is necessary to enable the first wedge-shaped sliding plate 3042A and the second wedge-shaped sliding plate 3042B to move in the direction of approaching or moving away from each other. For example, in the example of FIG. 17, when the first wedge-shaped sliding plate 3042A and the second wedge-shaped sliding plate 3042B move in the direction of approaching each other, the magnetic conductive block 303 will move in the direction of moving away from the permanent magnet slot; when the first wedge-shaped sliding plate 3042A and the second wedge-shaped sliding plate 3042B move in the direction of moving away from each other, the magnetic conductive block 303 will move in the direction of approaching the permanent magnet slot.

[0316] In order to achieve the above purpose, in some embodiments of the present application, the rotation directions of the first external thread 3061 and the second external thread 3062 can be set to be opposite. For example, the first external thread 3061 is a right-handed thread, and the second external thread 3062 is a left-handed thread; or, the first external thread 3061 is a left-handed thread, and the second external thread 3062 is a right-handed thread.

[0317] In some embodiments, the rotor core 301 includes a core support 3012 and a plurality of punching sheets 3013. The core support 3012 is sleeved on the rotating shaft 305 and fixedly connected with the rotating shaft 305. The plurality of punching sheets 3013 are arranged in a stacked manner in the axial direction and sleeved on the core support 3012. The aforementioned transmission screw rod 306 is axially arranged in the core support 3012.

[0318] According to the above technical means, the rotor core is arranged in a split structure composed of a core support and punching sheets, which can save the amount of silicon steel material and reduce the cost of the rotor assembly.

[0319] In some embodiments, the rotor assembly 300 further includes a driving unit fixedly connected with the rotor core 301, used for driving the transmission screw rod 306 to rotate. The driving unit can be a driving motor, or the driving unit can also be a hydraulic motor, etc.

[0320] In some embodiments, the rotor assembly 300 further includes a sensor and a control unit.

[0321] The sensor is used to determine the position of the magnetic conductive block 303. According to the different arrangement positions of the sensor, there are various methods for determining the position of the magnetic conductive block 303.

[0322] As an implementation manner, the sensor can be a distance sensor, which can be arranged on one side of the magnetic block 303 in a radial direction, for example, on the side of the magnetic block 303 close to the rotating shaft 305, for measuring the distance between the end of the sensor and the end surface of the magnetic block 303 close to the rotating shaft 305, and determining the position of the magnetic block 303 according to the distance.

[0323] Alternatively, the distance sensor can also be arranged on one end of the first wedge-shaped slide plate 3042A and / or the second wedge-shaped slide plate 3042B in an axial direction, for measuring the distance between the end of the sensor and the first wedge-shaped slide plate 3042A, which can also reflect the position of the magnetic block 303.

[0324] As another implementation manner, the sensor can also be a sensor for measuring the rotation angle, for example, a Hall sensor, which can be used to measure the rotation angle of the transmission screw 306, and determine the position of the magnetic block 303 according to the change amount of the rotation angle.

[0325] The control unit is connected with the sensor and the driving unit, for determining the air gap magnetic field strength of the rotor assembly 300 according to the position of the magnetic block 303, and controlling the driving unit to drive the transmission screw 306 according to the air gap magnetic field strength and the target magnetic field strength value, so as to adjust the position of the magnetic block 303, and adjust the air gap magnetic field strength of the rotor assembly 300 to the target magnetic field strength value.

[0326] It should be understood that the position of the magnetic block 303 and the air gap magnetic field strength value usually have a one-to-one corresponding relationship, when the position of the magnetic block 303 is adjusted according to the target magnetic field strength value, the target position of the magnetic block 303 can be determined according to the mapping relationship between the position of the magnetic block 303 and the magnetic field strength established in advance; and then the target stroke of the driving unit can be determined according to the deviation between the target position and the current position of the magnetic block 303; and the control signal is sent to the driving unit according to the target stroke of the driving unit, so as to move the magnetic block 303 to the target position.

[0327] According to the above technical means, the radial position of the magnetic block is detected by the sensor, and then the main magnetic field strength is determined, and the magnetic field strength of the rotor assembly is adjusted according to the main magnetic field strength, so that the magnetic field strength of the rotor assembly is measurable and the adjustment process is controllable.

[0328] FIG. 19 is a schematic structural diagram of a rotor assembly 400 provided by an embodiment of the present application, and FIG. 20 is a D-D cross-sectional view of FIG. 19. In order to facilitate the description, part of the structure in the rotor assembly 400 is hidden in FIG. 20.

[0329] In combination with FIGS. 19 and 20, the rotor assembly 400 in the embodiment of the present application includes a rotor core 401, a permanent magnet 402, a magnetic block 403, and a moving unit 404.

[0330] The rotor core 401 has a plurality of permanent magnet grooves 4011 distributed along the circumferential direction. It should be noted that the circumferential direction herein refers to the circumferential direction around the axial direction of the rotor core 401, and the axial direction refers to the direction of the central axis of the rotor assembly 400.

[0331] In some embodiments, the permanent magnet grooves 4011 include first permanent magnet grooves 40111 and second permanent magnet grooves 40112. The first permanent magnet grooves 40111 and the second permanent magnet grooves 40112 are symmetrically arranged about the D-axis center line. The plurality of first permanent magnet grooves 40111 and the plurality of second permanent magnet grooves 40112 in the rotor assembly 400 are alternately arranged and radially arranged, that is, the first permanent magnet grooves 40111 and the second permanent magnet grooves 40112 are arranged in a V shape.

[0332] Such a rotor structure with V-shaped permanent magnet grooves has the advantages of small magnetic leakage coefficient, no need to use magnetic isolation measures on the shaft, easy control of pole arc coefficient, high mechanical strength of rotor lamination, and no easy deformation of the rotor after installation, and can be applied in many fields such as rail transit and electric vehicles.

[0333] It should be further noted that the arrangement of the permanent magnet grooves in the rotor assembly provided by the embodiments of the present application is not limited to the above-mentioned V-shaped arrangement, and the arrangement of the permanent magnet grooves can be any one of radial type, tangential type or mixed type.

[0334] The permanent magnets 402 are arranged in the permanent magnet grooves 4011. The permanent magnet in the embodiments of the present application refers to a magnet that can maintain magnetism for a long time, such as natural magnetite (ferromagnetic ore) and artificial magnetic steel (for example, iron-nickel-cobalt magnetic steel, neodymium-iron-boron magnetic steel, etc.).

[0335] The magnetic conductive blocks 403 are arranged corresponding to the permanent magnet grooves 4011, and each magnetic conductive block 403 is arranged along the radial direction on the side of the corresponding permanent magnet groove 4011 close to the shaft 405.

[0336] The plurality of moving units 404 are respectively connected with the plurality of magnetic conductive blocks 403, and are used to drive the magnetic conductive blocks 403 to move along the radial direction between a first position close to the permanent magnet grooves 4011 and a second position away from the permanent magnet grooves 4011, so as to adjust the magnetic field distribution of the rotor assembly 400.

[0337] According to the principle of minimum magnetic resistance, the magnetic field will be distributed along the direction with smaller magnetic resistance. The magnetic resistance of the magnetic conductive blocks 403 is much smaller than that of air. Therefore, in the rotor assembly 400, the magnetic lines of the permanent magnet magnetic field generated by the permanent magnets 402 will preferentially pass through the magnetic conductive blocks 403; when the magnetic conductive blocks 403 move under the action of the moving units 404, the magnetic field distribution in the rotor assembly 400 changes accordingly.

[0338] More specifically, when the magnetic conducting block 403 moves to the first position close to the permanent magnet slot 4011, the rotor permanent magnet field will gather to the position of the magnetic conducting block 403; or in other words, in the case that the magnetic conducting block 403 is located at the first position close to the permanent magnet slot 4011, the rotor permanent magnet field does not pass through the air gap of the rotor assembly 400; or in other words, in the case that the magnetic conducting block 403 is located at the first position close to the permanent magnet slot 4011, the air gap magnetic field of the rotor assembly 400 is 0.

[0339] When the magnetic conducting block 403 moves to the second position away from the permanent magnet slot 4011, an air gap is formed between the magnetic conducting block 403 and the rotor core 401, and the magnetic resistance of this position is large. The permanent magnet field of the permanent magnet 402 will preferentially pass through the rotor core 401 with small magnetic resistance, and at this time, the air gap magnetic field of the rotor assembly 400 has a large magnetic field strength.

[0340] When the magnetic conducting block 403 is at different positions between the first position and the second position, the width of the air gap between the magnetic conducting block 403 and the rotor core 401 is different, thereby causing the magnetic conducting block 403 to have different influences on the air gap magnetic field of the rotor assembly 400; that is, by adjusting the position of the magnetic conducting block 403, the permanent magnet field of the rotor assembly 400 can be adjusted.

[0341] In some embodiments, the magnetic conducting block 403 is made of a material with high saturation magnetic induction, for example, 1J22 alloy, 2J10 alloy, 1J85 alloy, etc., which has a saturation magnetic induction of 2.4T or above, much larger than the saturation magnetic induction of air and silicon steel sheet. The magnetic conducting block 403 made of a material with high saturation magnetic induction can meet the adjustment requirement of the magnetic flux of the rotor assembly 400 at the minimum size.

[0342] The moving unit 404 includes a first moving unit 404A arranged at the first end of the magnetic conducting block 403 along the axial direction, which can be any end of the magnetic conducting block 403 along the axial direction, for example, in the view of FIG. 20, the first moving unit 404A is located at the left side of the magnetic conducting block 403 along the axial direction.

[0343] The first moving unit 404A includes a first lead screw 4041A and a first moving seat 4042A connected with the magnetic conducting block 403, and the first lead screw 4041A drives the first moving seat 4042A to move through the threaded transmission between the first moving seat 4042A and the first lead screw 4041A, so as to drive the magnetic conducting block 403 to move.

[0344] The first moving seat 4042A and the magnetic conducting block 403 can be connected by any one of welding, threaded connection, riveting or bonding, etc.

[0345] The extension direction of the first screw rod 4041A is the radial direction of the rotor assembly 400, and the threaded transmission between the first screw rod 4041A and the first moving seat 4042A can convert the rotation of the first screw rod 4041A into the movement of the first moving seat 4042A along the radial direction, and the first moving seat 4042A drives the magnetic conductive block 403 to move along the radial direction.

[0346] The first screw rod 4041A is provided with external threads, and the first moving seat 4042A is provided with internal threads, and the tooth type, pitch and rotation direction of the external threads and the internal threads are the same.

[0347] According to the above technical means, the movement of the magnetic conductive block is converted into the rotation of the first screw rod by the threaded transmission between the first screw rod and the first moving seat, so that the radial position of the magnetic conductive block can be adjusted steplessly, thereby adjusting the air gap magnetic field strength of the rotor assembly.

[0348] In some embodiments, the rotor assembly 400 further comprises a driving unit 406 and a transmission unit 407, and the transmission unit 407 is arranged between the driving unit 406 and the first screw rod 4041A.

[0349] The driving unit 406 can be a driving motor, which can be an inner rotor motor or an outer rotor motor.

[0350] The transmission unit 407 comprises a first gear 4071 and a plurality of second gears 4072 which are engaged with each other. The first gear 4071 is fixedly connected to the output end of the driving unit 406, and the plurality of second gears 4072 are respectively fixed to one end of the plurality of first screw rods 4041A close to the rotating shaft 405. The driving unit 406 drives the plurality of first screw rods 4041A to rotate through the engagement of the first gear 4071 and the plurality of second gears 4072.

[0351] According to the above technical means, the axial rotation of the driving unit is converted into the rotation of the first screw rod around its axis by using the gear mechanism, which has a compact structure and high reliability.

[0352] In some embodiments, as shown in FIG. 20, the driving unit 406 is an outer rotor motor 4061, the stator of the outer rotor motor 4061 is sleeved on the rotating shaft 405 of the rotor assembly 400 and is fixedly connected with the rotating shaft 405, and the rotation axis of the rotor of the outer rotor motor 4061 coincides with the axis of the rotor assembly 400.

[0353] The first gear 4071 and the second gear 4072 are bevel gears (also known as umbrella gears), the first gear 4071 is fixedly connected with the rotor of the outer rotor motor 4061, and the intersection angle between the rotation axis of the first gear 4071 and the rotation axis of the second gear 4072 is 90 degrees.

[0354] According to the above technical means, the driving unit formed by the outer rotor motor and the transmission unit formed by the mutually meshed bevel gears realize the reversing of the rotary drive by using the limited space in the rotor assembly, and the driving and transmission mode is reliable and compact in structure, which is beneficial to the miniaturization of the permanent magnet synchronous motor.

[0355] In some embodiments, as shown in FIG. 21, the moving unit 404 further comprises a second moving unit 404B arranged at the second end of the magnetic conducting block 403 along the axial direction, and the second moving unit 404B is arranged on the two sides of the magnetic conducting block 403 along the axial direction respectively with the first moving unit 404A.

[0356] The second moving unit 404B comprises a second lead screw 4041B and a second moving base 4042B connected with the magnetic conducting block 403, and the second lead screw 4041B drives the second moving base 4042B to move through the threaded transmission between the second lead screw 4041B and the second moving base 4042B, so as to drive the magnetic conducting block 403 to move.

[0357] The connection between the second moving base 4042B and the magnetic conducting block 403 can be any one of welding, threaded connection, riveting or bonding.

[0358] The extension direction of the second lead screw 4041B is the radial direction of the rotor assembly 400, and the threaded transmission between the second lead screw 4041B and the second moving base 4042B can convert the rotation of the second lead screw 4041B into the movement of the second moving base 4042B along the radial direction, and the second moving base 4042B drives the magnetic conducting block 403 to move along the radial direction.

[0359] The second lead screw 4041B is provided with external threads, and the second moving base 4042B is provided with internal threads, and the tooth type, pitch and rotation direction of the external threads and the internal threads are the same.

[0360] According to the above technical means, the second moving unit is arranged at the other end of the magnetic conducting block along the axial direction, and the second moving unit can jointly act with the first moving unit to drive the magnetic conducting block to move, so as to avoid the inclination of the magnetic conducting block during the movement.

[0361] In some embodiments, continuing to refer to FIG. 21, the transmission unit 407 further comprises a transmission shaft 4073, a third gear 4074, a fourth gear 4075 and a plurality of fifth gears 4076.

[0362] The transmission shaft 4073 is arranged along the axial direction of the rotor assembly 400 and is rotatably connected with the rotor core 401.

[0363] The third gear 4074 and the fourth gear 4075 are fixed at the two ends of the transmission shaft 4073 along the axial direction, and the third gear 4074 is meshed with the second gear 4072.

[0364] The plurality of fifth gears 4076 are respectively fixed at one end of the plurality of second lead screws 4041B close to the rotating shaft 405, and are engaged with the fourth gears 4075.

[0365] FIG. 22 is a schematic diagram of the transmission of FIG. 21, wherein the arrows in FIG. 22 represent the rotating directions of the rotating components and the moving directions of the first moving seat 4042A and the second moving seat 4042B in the moving units. It should be understood that FIG. 22 is described by taking the example that the magnetic conductive block 403 moves away from the rotating shaft 405.

[0366] As shown in FIG. 22, the second gears 4072 drive the transmission shaft 4073 and the fourth gears 4075 to rotate through the engagement between the second gears 4072 and the third gears 4074, and the fifth gears 4076 drive the second lead screws 4041B to rotate synchronously with the first lead screws 4041A under the action of the fourth gears 4075, so as to make the first moving seat 4042A and the second moving seat 4042B move synchronously.

[0367] According to the above technical means, the transmission shaft arranged between the first moving unit and the second moving unit is used to make the first moving seat and the second moving seat move synchronously through the gear engagement, so that the inclination of the magnetic conductive block during the movement can be avoided.

[0368] In some embodiments, continuing to refer to FIG. 22, the rotating directions of the first lead screws 4041A and the second lead screws 4041B are opposite under the action of the plurality of gears. In order to ensure that the moving directions of the first moving seat 4042A and the second moving seat 4042B are the same, the thread rotation directions of the first lead screws 4041A and the second lead screws 4041B can be set to be opposite. For example, the first lead screws 4041A are right-handed, and the second lead screws 4041B are left-handed; or the first lead screws 4041A are left-handed, and the second lead screws 4041B are right-handed.

[0369] According to the above technical means, the thread rotation directions of the first lead screws and the second lead screws are set to be different, so that when the first lead screws and the second lead screws rotate reversely under the action of the transmission unit, the moving directions of the first moving seat and the second moving seat are consistent.

[0370] In some embodiments, the rotor core 401 includes a core support 4012 and a plurality of laminations 4013. The core support 4012 is sleeved on the rotating shaft 405 and is fixedly connected with the rotating shaft 405. The plurality of laminations 4013 are arranged in an axial direction and are sleeved on the core support 4012. The transmission shaft 4073 is axially arranged in the core support 4012.

[0371] According to the above technical means, the rotor core is set to be a split structure composed of the core support and the laminations, so that the amount of silicon steel material can be saved, and the cost of the rotor assembly can be reduced.

[0372] It can be understood that, as a possible implementation manner, the technical solution provided by the embodiment of the present application can also not set the foregoing transmission shaft 4073 and the third gear 4074 between the first moving unit 404A and the second moving unit 404B, but a driving unit is separately set for the second moving unit 404B. For example, a separately set second outer rotor motor is used to provide power for the fourth gear 4075, and the power is transmitted to the second lead screw 4041B through the meshing of the fourth gear 4075 and the fifth gear 4076, so as to drive the second moving seat 4042B to move. In this technical solution, by controlling the driving units on both sides to synchronously output, the purpose of synchronous movement of the first moving seat 4042A and the second moving seat 4042B on both sides can also be achieved.

[0373] In some embodiments, the rotor assembly 400 further comprises a sensor and a control unit.

[0374] The sensor is used to determine the position of the magnetic conducting block 403. According to the different setting positions of the sensor, there are multiple methods to determine the position of the magnetic conducting block 403.

[0375] As an implementation manner, the sensor can be a distance sensor, which can be radially arranged on one side of the magnetic conducting block 403, for example, on the side of the magnetic conducting block 403 close to the rotating shaft 405, used to measure the distance between the end of the sensor and the end face of the magnetic conducting block 403 close to the rotating shaft 405, and determine the position of the magnetic conducting block 403 according to the distance. Alternatively, since the first moving seat 4042A or the second moving seat 4042B moves synchronously with the magnetic conducting block 403, the distance sensor can also be radially arranged on one side of the first moving seat 4042A or the second moving seat 4042B, for example, on the side of the first moving seat 4042A close to the rotating shaft 405, used to measure the distance between the end of the sensor and the end face of the first moving seat 4042A close to the rotating shaft 405, which can also reflect the position of the magnetic conducting block 403.

[0376] As another implementation manner, the sensor can also be a sensor for measuring the rotation angle, for example, a Hall sensor, which can be used to measure the rotation angle of any gear or driving motor, and determine the position of the magnetic conducting block 403 through the transmission ratio of the transmission unit 407.

[0377] The control unit is connected with the sensor and the driving unit 406, used to determine the air gap magnetic field strength of the rotor assembly 400 according to the position of the magnetic conducting block 403, control the driving unit 406 to drive the transmission unit 407 according to the air gap magnetic field strength and the target magnetic field strength value, and adjust the position of the magnetic conducting block 403, so as to adjust the air gap magnetic field strength of the rotor assembly 400 to the target magnetic field strength value.

[0378] It should be understood that the position of the magnetic conductive block 403 generally has a one-to-one correspondence with the air gap magnetic field strength value. When adjusting the position of the magnetic conductive block 403 according to the target magnetic field strength value, the target position of the magnetic conductive block 403 can be determined according to the pre-established mapping relationship between the position of the magnetic conductive block 403 and the magnetic field strength. Then, the target stroke of the driving unit 406 is determined according to the deviation between the target position and the current position of the magnetic conductive block 403 and the transmission ratio of the transmission unit 407. According to the target stroke of the driving unit 406, a control signal is sent to the driving unit 406 to move the magnetic conductive block 403 to the target position by the driving unit 406 and the transmission unit 407.

[0379] According to the above technical means, the radial position of the magnetic conductive block is detected by the sensor, and then the main magnetic field strength is determined. The magnetic field strength of the rotor assembly can be measured and the adjustment process is controllable according to the main magnetic field strength.

[0380] In some embodiments, referring to FIG. 20, the first moving unit 404A further comprises a first fixed seat 4043A fixedly connected with the rotor core 401, and the first fixed seat 4043A is provided with a first support 4044A and a second support 4045A at two ends in the radial direction, respectively. The first screw rod 4041A is movably connected with the first support 4044A and the second support 4045A.

[0381] In some embodiments, the first fixed seat 4043A can be a split structure shown in FIG. 23, which comprises a first bottom plate 40431A, a first support 4044A and a second support 4045A.

[0382] The first bottom plate 40431A is in the shape of a rectangular plate, and the first support 4044A and the second support 4045A are respectively arranged at two ends of the first bottom plate 40431A in the length direction.

[0383] The first support 4044A is arranged at one end close to the rotating shaft 405, and the second support 4045A is arranged at one end away from the rotating shaft 405. The first support 4044A is provided with a first opening 40441A, and the second support 4045A is provided with a second opening 1451A. When the first support 4044A and the second support 4045A are fixed to the first bottom plate 40431A, the first opening 40441A and the second opening 40451A are concentric, and one end of the first screw rod 4041A close to the rotating shaft 405 is arranged in the first opening 40441A.

[0384] The first support 4044A and the second support 4045A can be connected to the first bottom plate 40431A by welding, riveting, bonding or screwing. For example, in the split structure shown in FIG. 23, the first support 4044A and the second support 4045A are respectively provided with a first through hole 40442A and a second through hole 40452A, and a threaded hole is correspondingly provided on the first bottom plate 40431A. A threaded connecting member (such as a screw) can be passed through the first through hole 40442A, the second through hole 40452A and the threaded hole on the first bottom plate 40431A, so as to fix the first support 4044A and the second support 4045A on the first bottom plate 40431A.

[0385] In some embodiments, a first bearing is arranged between the first lead screw 4041A and the first opening 40441A, and a second bearing is arranged between the second opening 40451A, which can reduce the rotation resistance of the first lead screw 4041A.

[0386] The first bearing and the second bearing can be rolling bearings or sliding bearings, and the present application does not limit the same.

[0387] In some embodiments, the first fixed seat 4043A can also be an integral structure as shown in FIG. 24. It can be processed by milling, drilling and other processes from the same blank. Specifically, a rectangular groove is prepared in the middle of the cubic blank by milling, and the two ends of the rectangular groove form the first support 4044A and the second support 4045A. Circular through holes are processed on the end faces of the first support 4044A and the second support 4045A to form the first opening 40441A and the second opening 40451A.

[0388] In some embodiments, referring to FIG. 21, the second moving unit 404B further includes a second fixed seat 4043B, which is fixedly connected with the rotor core 401. The second fixed seat 4043B is provided with a third support 4044B and a fourth support 4045B at two ends in the radial direction respectively. The second lead screw 4041B is movably connected with the third support 4044B and the fourth support 4045B.

[0389] In some embodiments, the second fixed seat 4043B can be a split structure, which includes a second bottom plate 1431B, a third support 4044B and a fourth support 4045B.

[0390] The second bottom plate 40431B is in the shape of a rectangular plate, and the third support 4044B and the fourth support 4045B are respectively arranged at two ends of the second bottom plate 40431B in the length direction.

[0391] The third support 4044B is arranged at one end close to the rotating shaft 405, and the fourth support 4045B is arranged at one end away from the rotating shaft 405. The third support 4044B is provided with a third opening 40441B, and the fourth support 4045B is provided with a fourth opening 40451B. When the third support 4044B and the fourth support 4045B are fixed to the second bottom plate 40431B, the third opening 40441B and the fourth opening 40451B are concentric, and the second screw rod 4041B is arranged in the third opening 40441B at one end close to the rotating shaft 405.

[0392] The third support 4044B and the fourth support 4045B can be connected to the second bottom plate 40431B by welding, riveting, bonding or screwing. For example, in the split structure shown in FIG. 23, the third support 4044B and the fourth support 4045B are respectively provided with a third through hole 40442B and a fourth through hole 40452B, and the second bottom plate 40431B is provided with a threaded hole corresponding thereto. A threaded connecting member (such as a screw) can be arranged through the third through hole 40442B, the fourth through hole 40452B and the threaded hole of the second bottom plate 40431B, so as to fix the third support 4044B and the fourth support 4045B to the second bottom plate 40431B.

[0393] In some embodiments, the third opening 40441B and the fourth opening 40451B are respectively provided with a third bearing and a fourth bearing, which can reduce the rotation resistance of the second screw rod 4041B.

[0394] The third bearing and the fourth bearing can be rolling bearings or sliding bearings, and the present application is not limited thereto.

[0395] In some embodiments, the second fixing seat 4043B can also be an integral structure as shown in FIG. 24. It can be processed by milling, drilling and other processes from the same blank. Specifically, a rectangular groove is prepared in the middle of a cubic blank by milling, and the two ends of the rectangular groove form the third support 4044B and the fourth support 4045B. Circular through holes are processed on the end faces of the third support 4044B and the fourth support 4045B to form the third opening 40441B and the fourth opening 40451B.

[0396] FIG. 25 is a schematic structural diagram of a rotor assembly 500 according to another embodiment of the present application. The rotor assembly 500 includes a rotor core 501, a permanent magnet 502, a magnetic conducting block 503 and a rotating shaft 504.

[0397] The rotor core 501 has a plurality of permanent magnet grooves 5011 uniformly distributed in the circumferential direction. In the embodiment of the present application, the circumferential direction refers to the circumferential direction around the axial direction of the rotor core 501, and the axial direction refers to the direction of the central axis of the rotor core 501.

[0398] In some embodiments, the rotor core 501 includes a rotor support 5012 and a plurality of rotor laminations 5013. The rotor support 5012 is sleeved on the shaft 504 and fixedly connected with the shaft 504, and the plurality of rotor laminations 5013 are arranged in the axial direction and sleeved on the rotor support 5012.

[0399] The permanent magnet 502 is arranged in the permanent magnet groove 5011. The permanent magnet refers to a magnet that can maintain magnetism for a long time, such as natural magnetite (e.g., ferromagnetic ore) and artificial magnetic steel (e.g., iron-nickel-cobalt magnetic steel, neodymium-iron-boron magnetic steel, etc.).

[0400] The magnetic conducting block 503 is arranged corresponding to the permanent magnet groove 5011, and each magnetic conducting block 503 is arranged in the radial direction on the side of the corresponding permanent magnet groove 5011 close to the shaft.

[0401] The magnetic conducting block 503 is used to switch from a first position away from the permanent magnet groove 5011 to a second position close to the permanent magnet groove 5011 in the case of a fault event, to short-circuit the permanent magnet 502 and remove the electromagnetic coupling between the rotor assembly 500 and the stator assembly. The fault event in the embodiment of the present application can include at least one of the following: the stator assembly has a turn-to-turn short circuit, the temperature of the rotor assembly is greater than a first temperature threshold, the temperature of the stator assembly is greater than a second temperature threshold, and the rotational speed of the rotor assembly is greater than a first rotational speed threshold.

[0402] When the stator assembly has a turn-to-turn short circuit, the permanent magnet field of the rotor assembly interacts with the three-phase winding in the stator assembly, generating a large circulating current in the winding coil, causing the winding coil to heat up and threatening the safety of the stator assembly and the rotor assembly.

[0403] When the temperature of the rotor assembly and / or the stator assembly is high, the permanent magnet in the rotor assembly is prone to demagnetization, which has an irreversible impact on the motor.

[0404] It can be understood that the first temperature threshold and the second temperature threshold can be the same or different, and the embodiment of the present application does not make a specific limitation thereon.

[0405] When the rotational speed of the rotor is high, a large counter electromotive force is also generated in the stator winding. In this case, if the motor is to be continuously and stably output at this rotational speed, a demagnetizing current needs to be applied to the rotor assembly, which increases the power consumption of the motor.

[0406] Therefore, when any one or more of the above fault events occur, switching the position of the magnetic conducting block 503 can release the electromagnetic coupling between the rotor assembly and the stator assembly, thereby ensuring the safety of the motor.

[0407] According to the principle of minimum reluctance, the magnetic field will be distributed along the direction of smaller reluctance, that is, in the rotor assembly shown in FIG. 25, the magnetic lines of the permanent magnetic field generated by the permanent magnet 502 will preferentially pass through the magnetic conducting block 503. Therefore, when the magnetic conducting block 503 is in the first position and the second position, the magnetic field in the rotor assembly 500 presents different distributions.

[0408] More specifically, when the magnetic conducting block 503 is located at the first position away from the permanent magnet slot 5011, an air gap is formed between the magnetic conducting block 503 and the rotor core, and the position has a larger magnetic resistance. The permanent magnetic field of the permanent magnet will preferentially pass through the rotor core with smaller magnetic resistance, and at this time, the magnetic field strength of the air gap magnetic field of the rotor assembly 500 is larger. At this time, under the action of the stator magnetic field, the rotor assembly 500 can output with larger power. Therefore, the first position is also called the working position.

[0409] When the magnetic conducting block 503 is located at the second position close to the permanent magnet slot 5011 as shown in FIG. 26, the rotor permanent magnetic field will gather to the position of the magnetic conducting block 503; or in other words, when the magnetic conducting block is located at the first position close to the permanent magnet slot 5011, the rotor permanent magnetic field does not pass through the air gap of the rotor assembly; or in other words, when the magnetic conducting block is located at the first position close to the permanent magnet slot 5011, the air gap magnetic field of the rotor assembly is 0. In this case, when the rotor assembly 500 rotates under the action of an external force, the stator winding will not cut the permanent magnetic field, thereby avoiding the generation of back electromotive force. Therefore, the second position is also called the protection position.

[0410] It should be noted that the present application does not limit the specific manner in which the magnetic conducting block 503 switches the position in response to the fault event. For example, the magnetic conducting block 503 can be switched to the second position under the action of the centrifugal force generated by the rotation of the rotor assembly or the magnetic force of the permanent magnet; or the magnetic conducting block 503 can be moved to the second position under the driving of an external driving unit.

[0411] According to the technical scheme provided in the embodiments of the present application, when a fault event occurs, the magnetic conducting block in the rotor assembly can be switched from the first position (working position) to the second position (protection position), the permanent magnetic flux of the rotor assembly is short-circuited, the air gap magnetic field strength is reduced, and the electromagnetic coupling between the rotor assembly and the stator winding is released. The technical scheme can ensure the safety of the transmission system when the permanent magnet motor fails.

[0412] In some embodiments, the magnetic conductive block 503 is made of a material with high saturation magnetic induction, such as 1J22 alloy, 2J10 alloy, 1J85 alloy, etc., which has a saturation magnetic induction of 2.4T or above, much higher than that of air and silicon steel sheet. The magnetic conductive block made of the material with high saturation magnetic induction can meet the requirement of adjusting the magnetic flux of the rotor assembly to the maximum in the minimum size.

[0413] In some embodiments, referring to FIG. 25 and FIG. 26, the permanent magnet slot 5011 includes a first permanent magnet slot 50111 and a second permanent magnet slot 50112. The first permanent magnet slot 50111 and the second permanent magnet slot 50112 are symmetrically arranged about the D-axis center line. The plurality of first permanent magnet slots 50111 and second permanent magnet slots 50112 in the rotor assembly 500 are alternately arranged and radially arranged, i.e., the first permanent magnet slot 50111 and the second permanent magnet slot 50112 are arranged in a V shape.

[0414] The rotor structure with the V-shaped permanent magnet slot has the advantages of small leakage coefficient, no need to use magnetic isolation measures on the shaft, easy to control the pole arc coefficient, high mechanical strength of the rotor lamination, and the rotor is not easy to deform after installation, which can be applied in many fields such as rail transit and electric vehicles.

[0415] It should be further noted that the arrangement of the permanent magnet slot in the rotor assembly provided by the embodiments of the present application is not limited to the above-mentioned V-shaped arrangement, and the arrangement of the permanent magnet slot can be any one of the radial type, tangential type or mixed type.

[0416] In the example shown in FIG. 25 and FIG. 26, the first permanent magnet slot 50111 and the second permanent magnet slot 50112 form a first opening at one end close to the shaft, and the width of the magnetic conductive block 503 perpendicular to the radial direction is not less than the width of the first opening, so that the end face of the magnetic conductive block 503 close to the permanent magnet slot 5011 can completely cover the first opening, which makes the proportion of the material with high permeability in the core larger when the magnetic conductive block 503 is in the first position, and is more conducive to guiding the magnetic field into the magnetic conductive block 503.

[0417] The rotor core 501 has a recess 5014 recessed towards the direction close to the permanent magnet slot 5011, which is arranged corresponding to the permanent magnet slot 5011 and located on the side of the permanent magnet slot 5011 close to the shaft.

[0418] Correspondingly, the end of the magnetic conductive block 503 close to the permanent magnet slot 5011 has a protrusion 5031, which matches the shape of the recess 5014, and when the magnetic conductive block 503 is in the first position, the protrusion extends into the recess 5014.

[0419] By setting the protruding part on the magnetic block 503 extending towards the direction of the permanent magnet slot, the permanent magnet magnetic field of the permanent magnet can be gathered in the magnetic block with smaller magnetic resistance more quickly when the magnetic block moves to the second position, thereby avoiding the core part from reaching the saturation state first.

[0420] In some embodiments, the rotor core 501 has a plurality of sliding grooves 5015 corresponding to the plurality of permanent magnet slots 5011. Each sliding groove 5015 is arranged along the radial direction, and the first end of each sliding groove 5015 along the radial direction is close to the permanent magnet slot 5011, and the second end is spaced apart from the rotating shaft of the rotor assembly 500. The magnetic block 503 can move in the sliding groove 5015 to move between the first position and the second position.

[0421] It should be understood that the radial direction herein can be understood as the direction perpendicular to the aforementioned axial direction.

[0422] The first end of the sliding groove 5015 has a recessed area 50151 which matches the shape of the protruding part 5031 of the magnetic block 503. Alternatively, the recessed area 50151 forms the recessed part 5014 described above.

[0423] In some embodiments, the rotor assembly 500 further comprises at least one retaining mechanism 505 connected with the plurality of magnetic blocks 503, for retaining the magnetic block 503 in the first position in the absence of a fault event, and releasing the magnetic block 503 in the event of a fault event, so that the magnetic block 503 can move to the second position.

[0424] According to the above technical solution, by setting the retaining mechanism in the rotor assembly, the position of the magnetic block is limited, so that the magnetic block can be retained in the working position in the absence of a fault, ensuring the normal operation of the motor.

[0425] In some embodiments, referring to FIG. 27, which is a partial cross-sectional view of A-A in FIG. 25, the specific structure of the retaining mechanism 505 is shown.

[0426] The retaining mechanism 505 in FIG. 27 includes a retaining disc 5051 which is sleeved on the rotating shaft 504 of the rotor assembly 500, and the end of the retaining disc 5051 away from the rotating shaft 504 is provided with a protruding edge 5052 which extends along the axial direction towards the side close to the magnetic block 503.

[0427] The protruding edge 5052 is used to constrain the magnetic block 503 in the first position in the absence of a fault event, and to separate from the magnetic block in the event of a fault event, so that the magnetic block can move to the second position.

[0428] According to the technical scheme, the protruding edge on the retaining disc is used to limit the magnetic conducting block, and the structure is reliable and easy to process.

[0429] In some embodiments, referring to Fig. 27, the magnetic conducting block 503 is provided with a locking buckle 5032 at one end close to the retaining disc 5051. In the case where no fault event occurs, the locking buckle 5032 can abut against the surface of the protruding edge 5052 on the side close to the rotating shaft 504 to constrain the magnetic conducting block in the first position. In the case where a fault event occurs, the locking buckle 5032 is separated from the protruding edge 5052 to release the constraint on the magnetic conducting block 503.

[0430] The locking buckle 5032 can be integrally formed with the magnetic conducting block 503 or be two separate parts independent of the magnetic conducting block 503, which can be fixedly connected through welding, bonding or threaded connection, and the present application does not make a specific limitation in this regard.

[0431] According to the technical scheme, the magnetic conducting block is clamped by the locking buckle and the protruding edge of the retaining disc, so that the magnetic conducting block can be locked in the working position.

[0432] In some embodiments, the retaining mechanism further comprises a constraint unit 5053 for applying axial constraint on the retaining disc 5051. In the case where no fault event occurs, the constraint unit 5053 can ensure that the retaining disc 5051 is located close to the magnetic conducting block 503, so that the protruding edge 5052 can constrain the magnetic conducting block in the first position. In the case where a fault event occurs, the constraint unit 5053 releases the constraint on the retaining disc 5051, and the retaining disc 5051 can move in the reverse direction away from the magnetic conducting block 503 under the action of the magnetic conducting block 503 or external force, so that the constraint between the protruding edge 5052 and the magnetic conducting block 503 is released, and the magnetic conducting block 503 moves from the first position to the second position.

[0433] According to the technical scheme, the constraint unit connected with the retaining disc can ensure that the constraint on the magnetic conducting block does not fail in the case where no fault event occurs, and ensure the normal operation of the motor. In the case where a fault event occurs, the constraint on the magnetic conducting block can be released in time to switch the position of the magnetic conducting block.

[0434] In some embodiments, as shown in Fig. 27, the retaining mechanism 505 further comprises a limiting unit 5054, which is arranged in the axial direction and spaced apart from the retaining disc 5051 on the side away from the magnetic conducting block 503.

[0435] The limiting unit 5054 is used to limit the moving distance of the retaining disc 5051 in the direction away from the magnetic conducting block 503 in the case where the axial constraint on the retaining disc 5051 is released.

[0436] The limiting unit 5054 can be a limiting ring shown in FIG. 27, which is sleeved on the rotating shaft 504 and fixedly connected with the rotating shaft 504, or the limiting unit 5054 can also be a plurality of limiting blocks fixed on the rotating shaft 5042, and the specific structure thereof is not limited in the embodiments of the present application.

[0437] According to the above technical means, when the axial constraint of the retaining disc is released, the axial position of the retaining disc is limited by the limiting unit, so as to avoid collision between the retaining disc and other components in the motor.

[0438] In some embodiments, as shown in FIG. 28, the convex edge 5052 is provided with a first inclined surface 50521, which extends away from the rotating shaft 504 along a first direction (as shown by the arrow in FIG. 28) from the side away from the magnetic block 503 to the side close to the magnetic block 503.

[0439] In the case of a fault event, the magnetic block 503 moves away from the rotating shaft under the action of centrifugal force and magnetic force, the magnetic block 503 applies a force perpendicular to the first inclined surface 50521 to the first inclined surface 50521, the first inclined surface 50521 decomposes the force into a horizontal component away from the first direction and a vertical component along the radial direction outward, under the action of the horizontal component, the retaining disc 5051 is pushed to move away from the side away from the first direction, so that the convex edge 5052 can be quickly separated from the magnetic block 503.

[0440] According to the above technical means, the convex edge and the lock catch are arranged in a conical surface matching manner, the centrifugal force and the magnetic force of the magnetic block are used to quickly switch the magnetic block from the working position to the protection position, and the retaining disc is pushed to move axially to achieve quick tripping.

[0441] In some embodiments, as shown in FIG. 29, the lock catch 5032 is provided with a second inclined surface 50321, which is parallel to the first inclined surface 50521, and when the magnetic block 503 is in the first position, the second inclined surface 50321 is in contact with the first inclined surface 50521 to form a surface contact between the lock catch 5032 and the convex edge 5052.

[0442] In some embodiments, as shown in FIGS. 27-29, the constraint unit 5053 is an explosion bolt 50531, which is used to connect the retaining disc 5051 and the rotor core 501, and can be separated in response to the occurrence of a fault event, thereby releasing the constraint on the retaining disc 5051.

[0443] As mentioned above, the rotor core 501 includes a rotor support 5012 and a plurality of rotor laminations 5013, and the explosion bolt 50531 is connected between the retaining disc 5051 and the rotor support 5012.

[0444] According to the above technical means, the constraint unit is set as an explosion bolt, which can ensure that the constraint of the retaining disc is released in time when the fault event occurs, and the magnetic conducting block is quickly tripped.

[0445] In some embodiments, the explosion bolt 50531 has an explosive inside and an igniter for being triggered and igniting the explosive in response to the occurrence of a fault event, so as to shear the shear lock or break along the weakened slot of the bolt, and realize the unlocking of the two separated bodies.

[0446] The igniter can be triggered in at least one of an electric, mechanical, pressure, and hydraulic manner. For example, the igniter can be triggered by receiving an electric current or voltage signal, or the igniter can be triggered by a mechanical device such as a hammer.

[0447] In some embodiments, referring to FIGS. 27-29, the retaining mechanism 505 further includes a protective cover 5055 arranged at an end of the retaining disc 5051 away from the magnetic conducting block 503, and the projection of the protective cover 5055 in the axial direction covers the explosion bolt 50531.

[0448] According to the above technical means, by arranging the protective cover, the debris of the explosion bolt after being detonated can be prevented from splashing into the motor.

[0449] In some embodiments, the constraint unit 5053 is a self-release bolt for connecting the retaining disc 5051 and the rotor core 501. More specifically, the self-release bolt is connected between the retaining disc 5051 and the rotor support 5012. The self-release bolt can be separated in response to the occurrence of a fault event, thereby releasing the constraint of the retaining disc.

[0450] According to the above technical means, the self-release bolt has the characteristics of no explosion, self-release, and reusability, and will not produce gas release and debris during the release process.

[0451] It can also be understood that when the constraint unit 5053 is a self-release bolt, since the bolt of this type will not produce debris due to explosion during the release process, the protective cover described above can no longer be arranged.

[0452] In some embodiments, the constraint unit 5053 is a driving device connected with the holding disc 5051, which is configured to limit the axial movement of the holding disc 5051. In the case where no fault event occurs, the driving device drives the holding disc 5051 to move axially to one end close to the magnetic block 503, so as to apply axial constraint to the holding disc 5051, and the convex edge 5052 constrains the magnetic block 503 in the first position; in the case where a fault event occurs, the driving device drives the holding disc 5051 to move axially away from the magnetic block 503, so as to release the constraint of the holding disc 5051 to the magnetic block 503.

[0453] According to the above technical means, the axial position of the holding disc is adjusted by using an independently arranged driving device, and the control logic is simple; in addition, the position of the magnetic block can be moved to any position between the working position and the protection position by using the driving device, so as to realize the adjustment between the maximum magnetic field and the minimum magnetic field.

[0454] In some embodiments, the above driving device can be any one of an electromagnetic driving unit, a hydraulic driving unit and a pneumatic driving unit. The electromagnetic driving unit can be, for example, an electric actuator, the hydraulic driving unit can be, for example, a hydraulic cylinder, and the pneumatic driving unit can be, for example, an air cylinder, and the specific type of the present embodiment is not limited.

[0455] The present embodiment also provides a permanent magnet synchronous motor, comprising a rotor assembly and a stator assembly, wherein the rotor assembly is any one of the rotor assembly 200, the rotor assembly 300, the rotor assembly 400 or the rotor assembly 500 described in the foregoing embodiments.

[0456] The permanent magnet synchronous motor can be applied in various fields such as aviation, national defense, industrial and agricultural production and daily life. Specifically, the motor can be applied to industrial driving devices, automation equipment, fans, pumps, compressors, machine tools, robots, and vehicles.

[0457] The vehicle can include a road vehicle, an air vehicle, a water vehicle, an industrial device, an agricultural device, or an entertainment device, etc.

[0458] For example, the water vehicle can be a hovercraft, a motorboat, a motorboat, a fishing boat, a cruise ship, a sailboat, a yacht, etc.

[0459] The air vehicle can be an airplane, and the road vehicle can be a vehicle.

[0460] The present embodiment also provides a vehicle, which comprises the rotor assembly 200, the rotor assembly 300, the rotor assembly 400 or the rotor assembly 500 described in the foregoing embodiments.

[0461] In some embodiments, the vehicle is a transportation vehicle. Illustratively, the vehicle is one of a commercial vehicle, a passenger vehicle, a motorcycle, a flying vehicle, and a train.

[0462] In some embodiments, the vehicle is an industrial vehicle or an engineering vehicle. Illustratively, the vehicle is one of a forklift, a trailer, a tractor, an excavator, a bulldozer, and a crane.

[0463] In some embodiments, the vehicle can be an electric vehicle or a fuel vehicle. Illustratively, the vehicle is one of a pure electric vehicle (PEV) or a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), a range extended electric vehicle (REEV), and a plug-in hybrid electric vehicle (PHEV).

[0464] In some embodiments, the vehicle can also be an agricultural device (e.g., a mower, a harvester, etc.), a recreational device, a toy vehicle, etc.

[0465] In some embodiments, the vehicle can also be a high-speed railway train, a multiple-unit train, a vehicle for urban rail transit, etc.

[0466] In the description of the present application, it should be understood that the terms “center”, “longitudinal”, “transverse”, “length”, “width”, “thickness”, “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential” and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0467] In addition, the terms “first” and “second” are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with “first” and “second” can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of “a plurality of” is at least two, such as two, three, etc., unless otherwise specifically limited.

[0468] In the present application, unless specifically defined otherwise, the terms "mounting", "connected", "connecting", "fixed", "fixedly connected", and the like, should be understood broadly, for example, can be fixed connection, can be detachable connection, or integral; can be mechanical connection, can be electrical connection; can be direct connection, or indirect connection via an intermediate medium; can be internal communication between two elements, or interaction between two elements, unless specifically defined otherwise. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0469] In the present application, unless specifically defined otherwise, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact via an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0470] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in the present application and the features of different embodiments or examples without contradiction.

[0471] The above is only the preferred embodiment of the present application, and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. Industrial applicability

[0472] The embodiment of the application provides a rotor assembly, a permanent magnet synchronous motor, a traction system and a vehicle, wherein the magnetic guide blocks corresponding to the multiple groups of permanent magnets are arranged in the rotor assembly, the position of the magnetic guide blocks is adjusted, different leakage magnetic fields are generated, the adjustment of the permanent magnet magnetic field is realized, the permanent magnet synchronous motor has a wide speed adjustment range, the power factor of the permanent magnet motor at high speed is improved, and the motor iron loss can be eliminated or reduced. When the magnetic guide block is moved to one end close to the permanent magnet, the rotor permanent magnet magnetic field can be gathered in the rotor assembly, so that when the motor stator winding inter-turn short circuit fault occurs, the larger counter electromotive force in the conductor during the counter dragging can be avoided, and the safety of the traction system is ensured.

Claims

1. A rotor assembly, comprising: a rotating shaft; a rotor core sleeved on the rotating shaft, having a plurality of permanent magnet slots uniformly distributed in a circumferential direction; a plurality of permanent magnets arranged in the permanent magnet slots; a plurality of magnetic conductive blocks corresponding to the plurality of permanent magnet slots, each of the magnetic conductive blocks being arranged in a radial direction on a side of the corresponding permanent magnet slot close to the rotating shaft; the magnetic conductive blocks are configured to move between a first position close to the permanent magnet slots and a second position away from the permanent magnet slots to adjust a magnetic field distribution of the rotor assembly. 2.The rotor assembly of claim 1, when the magnetic conductive blocks are in the first position, the magnetic conductive blocks abut against the rotor core on an end of the permanent magnet slots close to the rotating shaft in the radial direction. 3.The rotor assembly of claim 2, the permanent magnet slots include a first permanent magnet slot and a second permanent magnet slot symmetrically arranged about a D-axis center line; a first opening is formed by an end of the first permanent magnet slot close to the rotating shaft and an end of the second permanent magnet slot close to the rotating shaft, a width of the magnetic conductive blocks in a direction perpendicular to the radial direction is not less than a width of the first opening, so that when the magnetic conductive blocks are in the first position, an end face of the magnetic conductive blocks on the end of the permanent magnet slots close to the rotating shaft can cover the first opening. 4.The rotor assembly of claim 3, the rotor core has a recessed portion recessed toward the direction of the permanent magnet slots, the recessed portion is arranged corresponding to the permanent magnet slots and is located on a side of the permanent magnet slots close to the rotating shaft; an end of the magnetic conductive blocks close to the permanent magnet slots has a protruding portion, the protruding portion matches a shape of the recessed portion, and when the magnetic conductive blocks are in the first position, the protruding portion extends into the recessed portion. 5.The rotor assembly of claim 4, the protruding portion is a circular arc-shaped end face. 6.The rotor assembly of claim 4, the protruding portion includes a first end face and a second end face arranged in a V shape, an included angle formed by the first end face and the second end face is toward an end of the permanent magnet slots close to the rotating shaft. 7.The rotor assembly of claim 6, the included angle formed by the first end face and the second end face is an obtuse angle. 8.The rotor assembly of any one of claims 5-7, the rotor core has a plurality of sliding grooves arranged corresponding to the plurality of permanent magnet slots, each of the sliding grooves is arranged in the radial direction, a first end of the sliding groove close to the permanent magnet slots, a second end of the sliding groove spaced apart from the rotating shaft of the rotor assembly, and the magnetic conductive blocks are slidable in the sliding grooves to move between the first position and the second position; the first end of the sliding groove has a recessed area, the recessed area matches a shape of the protruding portion. 9.The rotor assembly of claim 8, an arc angle of the first permanent magnet slot and the second permanent magnet slot close to the rotating shaft is less than or equal to an arc angle of the first permanent magnet slot and the second permanent magnet slot away from the rotating shaft.

10. The rotor assembly of claim 9, wherein the first position is located at one end of the rotor shaft close to the first and second permanent magnet slots.

11. The rotor assembly of claim 10, wherein the first permanent magnet slot is provided with a first and a second flux barrier at two ends thereof, and the second permanent magnet slot is provided with a third and a fourth flux barrier at two ends thereof.

12. The rotor assembly of claim 11, further comprising a first and a second inner magnetic bridge corresponding to the permanent magnet slots, wherein the first inner magnetic bridge is located between the slide slot and the second flux barrier, and the second inner magnetic bridge is located between the slide slot and the fourth flux barrier.

13. The rotor assembly of claim 11, further comprising a first and a second outer magnetic bridge corresponding to the permanent magnet slots, wherein the first outer magnetic bridge is located between the first flux barrier and an outer edge of the rotor assembly, and the second outer magnetic bridge is located between the third flux barrier and an outer edge of the rotor assembly.

14. The rotor assembly of claim 13, wherein the first and third flux barriers extend through the rotor core in a radial direction.

15. The rotor assembly of claim 14, further comprising a rotor sheath surrounding an outer side of the rotor core.

16. The rotor assembly of claim 15, wherein the rotor sheath is made of carbon fiber or non-magnetic alloy material.

17. The rotor assembly of claim 3, wherein the rotor core comprises a core shaft core, a D-axis core and a Q-axis core; wherein the core shaft core is a sleeve close to a shaft center of the rotor core; the D-axis core is located between the first and second permanent magnet slots; the Q-axis core is located between two adjacent permanent magnet slots.

18. The rotor assembly of claim 17, wherein the core shaft core, the D-axis core and the Q-axis core are integrally formed.

19. The rotor assembly of claim 17, the core shaft core, the D-axis core and the Q-axis core are combined structures; the D-axis core is made of silicon steel material, amorphous material or nanocrystalline material; the Q-axis core is made of silicon steel material, amorphous material or nanocrystalline material.

20. The rotor assembly of claim 19, wherein the core shaft core and the Q-axis core are integrally formed, or the Q-axis core is connected to the core shaft core through a dovetail structure.

21. A permanent magnet synchronous motor comprising a rotor assembly and a stator assembly, wherein the rotor assembly is any one of claims 1-20.

22. A permanent magnet synchronous motor applied to a power system of an urban rail vehicle, wherein the vehicle power system comprises a plurality of permanent magnet synchronous motors for providing power to the vehicle, and the permanent magnet synchronous motor comprises a rotor assembly and a stator assembly, wherein the rotor assembly comprises: a rotor shaft; a rotor core having a plurality of permanent magnet slots uniformly distributed in a circumferential direction; permanent magnets sleeved on the rotor shaft and arranged in the permanent magnet slots. a plurality of magnetic-conducting blocks corresponding to the plurality of permanent-magnet grooves, each of the magnetic-conducting blocks being disposed along a radial direction on a side of a corresponding one of the permanent-magnet grooves close to the rotating shaft; the magnetic-conducting blocks are configured to: when the vehicle is in an idling operating condition, the magnetic-conducting blocks are located at a first position close to the permanent-magnet grooves to reduce iron loss of the permanent-magnet synchronous motor in the idling operating condition; when the vehicle is in a traction operating condition, the magnetic-conducting blocks are located at a second position away from the permanent-magnet grooves to increase air-gap magnetic field strength between the rotor assembly and the stator assembly.

23. The permanent-magnet synchronous motor of claim 22, the magnetic-conducting blocks are further configured to, when a speed of the vehicle is greater than a first speed threshold, move the magnetic-conducting blocks between the first position and the second position to adjust magnetic field distribution of the rotor assembly and increase a speed regulating range of the permanent-magnet synchronous motor; wherein the first speed threshold is related to a rated rotating speed of the permanent-magnet synchronous motor.

24. A power system applied to an urban rail transit vehicle for providing power for the vehicle, the power system comprising the permanent-magnet synchronous motor of claim 22 or 23.

25. An urban rail vehicle, the vehicle comprising: the permanent-magnet synchronous motor of claim 22 or 23, or the power system of claim 24.

26. A permanent-magnet synchronous traction motor applied to a traction system of a locomotive, the permanent-magnet synchronous traction motor comprising a rotor assembly and a stator assembly, the rotor assembly comprising: a rotating shaft; a rotor core sleeved on the rotating shaft and having a plurality of permanent-magnet grooves uniformly distributed along a circumferential direction; permanent magnets disposed in the permanent-magnet grooves; a plurality of magnetic-conducting blocks corresponding to the plurality of permanent-magnet grooves, each of the magnetic-conducting blocks being disposed along a radial direction on a side of a corresponding one of the permanent-magnet grooves close to the rotating shaft; the magnetic-conducting blocks are configured to, according to a running speed of the locomotive, move between a first position close to the permanent-magnet grooves and a second position away from the permanent-magnet grooves to adjust magnetic field distribution of the rotor assembly so that the permanent-magnet synchronous traction motor outputs constant power when driving the locomotive to work within a range of the running speed.

27. The permanent-magnet synchronous traction motor of claim 26, the magnetic-conducting blocks are further configured to: when a speed of the locomotive is greater than a first speed, the magnetic-conducting blocks are located at or close to the first position to reduce air-gap magnetic field strength of the rotor assembly and increase rotating speed of the permanent-magnet synchronous traction motor, the first speed being related to a rated rotating speed of the permanent-magnet synchronous traction motor.

28. A traction system applied to a locomotive, the traction system comprising the permanent-magnet synchronous traction motor of claim 26 or 27.

29. A locomotive comprising: the permanent-magnet synchronous traction motor of claim 26 or 27, or the traction system of claim 28.

30. A power system applied to a train, the power system comprising a plurality of permanent-magnet synchronous motors for driving the train to run, each of the permanent-magnet synchronous motors comprising a rotor assembly and a stator assembly; the rotor assembly comprising: a rotating shaft; a rotor core sleeved on the rotating shaft and having a plurality of permanent-magnet grooves uniformly distributed along a circumferential direction; permanent magnets disposed in the permanent-magnet grooves; permanent magnets, disposed in the permanent magnet slots; a plurality of magnetic conductive blocks, disposed corresponding to the plurality of permanent magnet slots, each of the magnetic conductive blocks is disposed on a side of a corresponding permanent magnet slot close to the rotating shaft in a radial direction, the magnetic conductive blocks are used to switch between a first position close to the permanent magnet slots and a second position away from the permanent magnet slots, so as to adjust the magnetic field distribution of the rotor assembly; the power system is configured to: in the case of an inter-turn short circuit fault of a target permanent magnet synchronous motor in the plurality of permanent magnet synchronous motors, switch the magnetic conductive blocks in the target permanent magnet synchronous motor to the first position, so as to short-circuit the main magnetic flux of the target permanent magnet synchronous motor, and make the target permanent magnet synchronous motor exit service.

31. A train comprising the power system of claim 30.

32. A permanent magnet synchronous motor applied to mobile equipment, the permanent magnet synchronous motor comprising a stator assembly and a rotor assembly, the rotor assembly comprising: a rotating shaft; a rotor core sleeved on the rotating shaft, having a plurality of permanent magnet slots uniformly distributed in a circumferential direction; permanent magnets disposed in the permanent magnet slots; a plurality of magnetic conductive blocks, disposed corresponding to the plurality of permanent magnet slots, each of the magnetic conductive blocks is disposed on a side of a corresponding permanent magnet slot close to the rotating shaft in a radial direction, the magnetic conductive blocks are used to switch between a first position close to the permanent magnet slots and a second position away from the permanent magnet slots, so as to adjust the magnetic field distribution of the rotor assembly; the magnetic conductive blocks are configured to: when the speed of the mobile equipment is greater than a first speed, move to the first position or close to the first position, so as to improve the efficiency of the permanent magnet synchronous motor in a high-speed working condition.

33. Mobile equipment comprising the permanent magnet synchronous motor of claim 32.

34. A permanent magnet synchronous motor comprising a stator assembly and a rotor assembly, the rotor assembly comprising: a rotating shaft; a rotor core sleeved on the rotating shaft, having a plurality of permanent magnet slots uniformly distributed in a circumferential direction; permanent magnets disposed in the permanent magnet slots; a plurality of magnetic conductive blocks, disposed corresponding to the plurality of permanent magnet slots, each of the magnetic conductive blocks is disposed on a side of a corresponding permanent magnet slot close to the rotating shaft in a radial direction, the magnetic conductive blocks are used to switch between a first position close to the permanent magnet slots and a second position away from the permanent magnet slots, so as to adjust the magnetic field distribution of the rotor assembly; the magnetic conductive blocks are further configured to: when the back electromotive force of the stator assembly increases, move from the second position to the direction close to the first position, so as to reduce the back electromotive force of the stator assembly.

35. A vehicle comprising the permanent magnet synchronous motor of claim 34.

36. The rotor assembly of claim 1, further comprising: a cam mechanism comprising a plurality of pin shafts and a cam disc, the plurality of pin shafts are respectively connected with the plurality of magnetic conductive blocks, the cam disc has a plurality of cam grooves corresponding to the plurality of pin shafts, the pin shafts are movably connected in the cam grooves in a limited manner. The cam disc is capable of rotating along the circumferential direction to drive the magnetic block to move along the radial direction between a first position close to the permanent magnet slot and a second position away from the permanent magnet slot, so as to adjust the magnetic field distribution of the rotor assembly.

37. The rotor assembly of claim 36, wherein the cam groove comprises at least one movement section and at least one rest section. When the pin shaft moves in the movement section, the magnetic block moves along the radial direction towards or away from the permanent magnet slot. When the pin shaft moves in the rest section, the magnetic block remains static along the radial direction.

38. The rotor assembly of claim 37, wherein the generatrix of the rest section is an arc, and the center of the arc coincides with the center of rotation of the cam disc.

39. The rotor assembly of claim 38, wherein the cam groove comprises a plurality of rest sections, and the diameters of the arcs of the generatrix of the plurality of rest sections are different.

40. The rotor assembly of claim 36, further comprising a driving unit configured to drive the cam disc to rotate along the circumferential direction.

41. The rotor assembly of claim 40, further comprising a displacement sensor and a control unit; the displacement sensor is configured to determine the position of the magnetic block; the control unit is connected with the displacement sensor and the driving unit, and is configured to determine the air gap magnetic field strength of the rotor assembly according to the position of the magnetic block, and to control the driving unit to drive the cam disc to rotate according to the air gap magnetic field strength and a target strength value, so as to adjust the position of the magnetic block to adjust the air gap magnetic field strength to the target strength value.

42. The rotor assembly of any one of claims 36-41, wherein the rotor assembly comprises two cam mechanisms, and the two cam mechanisms are arranged at two ends of the magnetic block along the axial direction of the rotor assembly, and the two cam discs are synchronously rotated to drive the magnetic block to move between the first position and the second position.

43. The rotor assembly of claim 42, further comprising a connecting shaft configured to connect the two cam discs to synchronously rotate the two cam discs.

44. The rotor assembly of any one of claims 36-41, wherein the cam mechanism further comprises a plurality of pull rods, and the pull rods are arranged in the magnetic block along the axial direction of the rotor assembly, and at least one end of the pull rods along the axial direction is provided with the pin shaft.

45. The rotor assembly of claim 1, further comprising: a plurality of moving units respectively connected with the plurality of magnetic blocks, and configured to drive the magnetic blocks to move along the radial direction between a first position close to the permanent magnet slot and a second position away from the permanent magnet slot, so as to adjust the magnetic field distribution of the rotor assembly. The moving unit comprises a first moving unit arranged at a first end of the magnetic block along the axial direction, the first moving unit comprises a first connecting rod and a first wedge-shaped slide plate, the first connecting rod is fixedly connected with the magnetic block, the first wedge-shaped slide plate is provided with a first guide groove which is inclined relative to the axial direction, and one end of the first connecting rod away from the magnetic block is in abutment with the first guide groove; when the first wedge-shaped slide plate moves along the axial direction, the first connecting rod and the magnetic block are guided to move along the radial direction.

46. The rotor assembly of claim 45, wherein a cross section of the first guide groove is T-shaped, one end of the first connecting rod away from the magnetic block is provided with a first T-shaped end head which is matched with the cross section shape of the first guide groove, and the first T-shaped end head is embedded in the first guide groove to slide in the first guide groove.

47. The rotor assembly of claim 46, further comprising a transmission screw rod which extends along the axial direction and is rotatably connected with the rotor core, and one end of the transmission screw rod close to the first moving unit is provided with a first external thread. The first wedge-shaped slide plate is provided with a first internal thread which penetrates through along the axial direction at a side close to the rotating shaft, the first internal thread is matched with the first external thread, and when the transmission screw rod rotates, the first wedge-shaped slide plate moves along the axial direction.

48. The rotor assembly of claim 47, The moving unit further comprises a second moving unit arranged at a second end of the magnetic block along the axial direction, the second moving unit comprises a second connecting rod and a second wedge-shaped slide plate, the second connecting rod is fixedly connected with the magnetic block, and the second wedge-shaped slide plate is provided with a second guide groove which is inclined relative to the axial direction, and one end of the second connecting rod away from the magnetic block is in abutment with the second guide groove. The first wedge-shaped slide plate and the second wedge-shaped slide plate move along the axial direction to approach or move away from each other, and the first connecting rod, the second connecting rod and the magnetic block are guided to approach or move away from the permanent magnet slot along the radial direction.

49. The rotor assembly of claim 48, The second guide groove is T-shaped in cross section, one end of the second connecting rod away from the magnetic block is provided with a second T-shaped end head which is matched with the cross section shape of the second guide groove, and the second T-shaped end head is embedded in the second guide groove to slide in the second guide groove.

50. The rotor assembly of claim 49, One end of the transmission screw rod close to the second moving unit is provided with a second external thread, the second wedge-shaped slide plate is provided with a second internal thread which penetrates through along the axial direction at a side close to the rotating shaft, the second internal thread is matched with the second external thread when the transmission screw rod rotates, and when the transmission screw rod rotates, the second wedge-shaped slide plate and the first wedge-shaped slide plate both move along the axial direction.

51. The rotor assembly of claim 50, wherein the first external thread and the second external thread are opposite in rotation direction.

52. The rotor assembly of any of claims 47-51, the rotor core comprising: The core support and a plurality of punching sheets The iron core support is sleeved on the rotating shaft and fixedly connected with the rotating shaft. The plurality of punching sheets are arranged in the axial direction and sleeved on the iron core support. The transmission screw rod is arranged in the iron core support in the axial direction.

53. The rotor assembly according to any one of claims 47-51, further comprising a driving unit fixedly connected with the rotor core and configured to drive the transmission screw rod to rotate.

54. The rotor assembly according to claim 53, further comprising a displacement sensor and a control unit. The displacement sensor is configured to determine the position of the magnetic conductive block. The control unit is connected with the displacement sensor and the driving unit and configured to determine the air gap magnetic field strength of the rotor assembly according to the position of the magnetic conductive block, and control the driving unit to drive the transmission screw rod to rotate according to the air gap magnetic field strength and a target strength value, so as to adjust the position of the magnetic conductive block and adjust the air gap magnetic field strength to the target strength value.

55. The rotor assembly according to any one of claims 47-51, wherein the transmission screw rod is made of a non-magnetic conductive material.

56. The rotor assembly according to claim 1, further comprising: a plurality of moving units respectively connected with the plurality of magnetic conductive blocks and configured to drive the magnetic conductive blocks to move along the radial direction between a first position close to the permanent magnet slot and a second position away from the permanent magnet slot, so as to adjust the magnetic field distribution of the rotor assembly. The moving unit comprises a first moving unit arranged at a first end of the magnetic conductive block in the axial direction, the first moving unit comprises a first screw rod and a first moving seat, the first moving seat is connected with the magnetic conductive block, and the first screw rod drives the first moving seat to move through threaded transmission between the first moving seat, so as to drive the magnetic conductive block to move.

57. The rotor assembly according to claim 56, further comprising a driving unit and a transmission unit. The transmission unit comprises a first gear and a plurality of second gears which are engaged with each other, the first gear is fixedly connected with the output end of the driving unit, the plurality of second gears are respectively fixed at one end of the plurality of first screw rods close to the rotating shaft of the rotor assembly, and the driving unit drives the plurality of first screw rods to rotate through the first gear and the plurality of second gears.

58. The rotor assembly according to claim 57, wherein the driving unit is an external rotor motor, the stator of the external rotor motor is sleeved on the rotating shaft and fixedly connected with the rotating shaft. The first gear and the second gear are bevel gears, the first gear is fixedly connected with the rotor of the external rotor motor, and the intersection angle between the rotation axis of the first gear and the rotation axis of the second gear is 90 degrees. 59.The rotor assembly of claim 58, wherein the moving unit further comprises a second moving unit arranged at a second end of the magnetic block along the axial direction, the second moving unit comprising a second screw rod and a second moving base, the second moving base being connected with the magnetic block, and the second screw rod driving the second moving base to move through threaded transmission between the second moving base and the second screw rod, so as to drive the magnetic block to move. 60.The rotor assembly of claim 59, wherein the transmission unit further comprises a transmission shaft, a third gear, a fourth gear, and a plurality of fifth gears; wherein the transmission shaft being arranged along the axial direction and rotatably connected with the rotor core; the third gear and the fourth gear being fixed at two ends of the transmission shaft along the axial direction, and the third gear being engaged with the second gear; the plurality of fifth gears being respectively fixed at one end of the plurality of second screw rods close to the rotating shaft, and engaged with the fourth gear; the second gear driving the transmission shaft and the fourth gear to rotate through engagement between the second gear and the third gear, and the fifth gears driving the second screw rods and the first screw rod to rotate synchronously under the action of the fourth gear, so as to drive the first moving base and the second moving base to move synchronously. 61.The rotor assembly of claim 60, wherein the first screw rod and the second screw rod are opposite in screw rotation direction. 62.The rotor assembly of claim 60, wherein the rotor core comprises a core support and a plurality of laminations; the core support being sleeved on the rotating shaft and fixedly connected with the rotating shaft; the plurality of laminations being arranged in layers along the axial direction and sleeved on the core support; the transmission shaft being arranged in the core support along the axial direction. 63.The rotor assembly of any one of claims 57-62, further comprising a sensor and a control unit; the sensor being configured to determine the position of the magnetic block; the control unit being connected with the sensor and the driving unit, and configured to determine the air gap magnetic field strength of the rotor assembly according to the position of the magnetic block, and control the driving unit to drive the transmission unit to adjust the position of the magnetic block according to the air gap magnetic field strength and a target magnetic field strength value, so as to adjust the air gap magnetic field strength to the target magnetic field strength value. 64.The rotor assembly of any one of claims 56-62, wherein the first moving unit further comprises a first fixed base fixedly connected with the rotor core, the first fixed base being provided with a first support and a second support at two ends along the radial direction, and the first screw rod being movably connected with the first support and the second support. 65.The rotor assembly of any one of claims 60-61, wherein the second moving unit further comprises a second fixed base fixedly connected with the rotor core, the second fixed base being provided with a third support and a fourth support at two ends along the radial direction, and the second screw rod being movably connected with the third support and the fourth support. 66.The rotor assembly of claim 1, The magnetic conducting block is further configured to switch from a first position away from the permanent magnet slot to a second position close to the permanent magnet slot in the event of a fault event, so as to short-circuit the permanent magnet by the magnetic conducting block, and to release the electromagnetic coupling between the rotor assembly and the corresponding stator assembly.

67. The rotor assembly of claim 66, further comprising at least one retaining mechanism; the retaining mechanism is connected with the plurality of magnetic conducting blocks, and is configured to retain the magnetic conducting blocks in the second position in the absence of the fault event; and in the event of the fault event, the magnetic conducting blocks are released to move to the second position.

68. The rotor assembly of claim 67, the retaining mechanism comprises: a retaining disc sleeved on a rotating shaft of the rotor assembly; an end of the retaining disc away from the rotating shaft is provided with a protrusion extending towards a side of the rotor assembly close to the magnetic conducting blocks along an axial direction of the rotor assembly, the protrusion is configured to constrain the magnetic conducting blocks in the first position in the absence of the fault event, and to separate from the magnetic conducting blocks in the event of the fault event, so as to move the magnetic conducting blocks to the second position.

69. The rotor assembly of claim 68, an end of the magnetic conducting blocks close to the retaining disc is provided with a lock catch configured to: abut against a surface of the protrusion close to the rotating shaft in the absence of the fault event, so as to constrain the magnetic conducting blocks in the first position; and separate from the protrusion in the event of the fault event, so as to release the constraint on the magnetic conducting blocks.

70. The rotor assembly of claim 69, the retaining mechanism further comprises a constraining unit configured to: exert a constraint on the retaining disc along the axial direction in the absence of the fault event, so as to constrain the magnetic conducting blocks in the first position by the protrusion; and release the constraint on the retaining disc along the axial direction in the event of the fault event, so as to separate the constraint between the protrusion and the magnetic conducting blocks, and move the magnetic conducting blocks to the second position.

71. The rotor assembly of claim 70, the retaining mechanism further comprises: a limiting unit spaced apart from the retaining disc along the axial direction and located on a side of the retaining disc away from the magnetic conducting blocks, the limiting unit is configured to limit a moving distance of the retaining disc away from the magnetic conducting blocks in the absence of the constraint on the retaining disc along the axial direction.

72. The rotor assembly of claim 71, a first inclined surface is provided on the protrusion and extends away from the rotating shaft along a first direction from a side of the protrusion away from the magnetic conducting blocks to a side of the protrusion close to the magnetic conducting blocks; in the event of the fault event, the magnetic conducting blocks move away from the rotating shaft under the action of centrifugal force and magnetic force, and push the retaining disc to move along the axial direction away from the magnetic conducting blocks.

73. The rotor assembly of claim 70, The constraint unit comprises an explosive bolt for connecting the retaining disc and the rotor core, the explosive bolt being capable of explosive separation in response to occurrence of the failure event to release the constraint on the retaining disc.

74. The rotor assembly of claim 70, The constraint unit comprises a self-releasing bolt for connecting the retaining disc and the rotor core, the self-releasing bolt being capable of separation in response to occurrence of the failure event to release the constraint on the retaining disc.

75. The rotor assembly of claim 73, the retaining mechanism further comprising a shield, the shield being disposed at an end of the retaining disc distal to the flux guide block, and a projection of the shield along the axial direction covering the explosive bolt.

76. The rotor assembly of claim 70, the constraint unit being a driving device connected to the retaining disc, the driving device being configured to: in the absence of the failure event, drive the retaining disc to move along the axial direction to an end proximal to the flux guide block to apply a constraint on the retaining disc along the axial direction such that the flange constrains the flux guide block at the first position; and in the presence of the failure event, drive the retaining disc to move along the axial direction away from the flux guide block to release the constraint of the retaining disc on the flux guide block.

77. The rotor assembly of claim 76, the driving unit being one of: an electromagnetic driving unit, a hydraulic driving unit, and a pneumatic driving unit.

78. The rotor assembly of claim 73, the explosive bolt having an explosive and an igniter inside, the igniter being configured to be triggered and ignite the explosive in response to occurrence of the failure event to cause the explosive bolt to explode and separate; the triggering of the igniter comprises at least one of: electrical triggering, mechanical triggering, pressure triggering, and hydraulic triggering.

79. The rotor assembly of any one of claims 66-78, the failure event comprising at least one of: an inter-turn short circuit of the stator assembly; a temperature of the rotor assembly being greater than a first temperature threshold; a temperature of the stator assembly being greater than a second temperature threshold; a rotational speed of the rotor assembly being greater than a first rotational speed threshold.

80. A permanent magnet synchronous motor comprising a stator assembly and a rotor assembly as claimed in any one of claims 36-79.

81. A vehicle comprising: the rotor assembly as claimed in any one of claims 36-79, or the permanent magnet synchronous motor as claimed in claim 80.

Images