Rotor assembly, permanent magnet synchronous motor and vehicle

Abstract

The embodiment of the invention provides a rotor assembly, a permanent magnet synchronous motor and a vehicle. The rotor assembly comprises a rotor iron core which is provided with a plurality of permanent magnet grooves which are uniformly distributed along the circumferential direction; the permanent magnets are arranged in the permanent magnet grooves; the plurality of magnetic conductive blocks are arranged corresponding to the plurality of permanent magnet grooves; the cam mechanism comprises a plurality of pin shafts and a cam disc, the plurality of pin shafts are connected with the plurality of magnetic conductive blocks respectively, the cam disc is provided with a plurality of cam grooves corresponding to the plurality of pin shafts, the pin shafts can be movably connected to the cam grooves in a limited mode, the cam disc can rotate in the circumferential direction, and the cam disc can rotate in the circumferential direction. The motor drives the magnetic conductive block to move between a first position close to the permanent magnet groove and a second position far away from the permanent magnet groove in the radial direction so as to adjust the magnetic field distribution of the rotor assembly.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and more specifically, to a rotor assembly, a permanent magnet synchronous motor and a vehicle. Background Art

[0002] Permanent magnet synchronous motors have a series of advantages such as small size, low weight and high power density. They have been widely used in electric vehicles, high-speed railways, urban rail transit, aerospace and industrial production.

[0003] The air gap magnetic field of a permanent magnet synchronous motor is difficult to adjust, resulting in a narrow constant power region and limited width operation. It is necessary to use weak magnetic field control (also known as magnetic modulation) to increase the speed.

[0004] A feasible magnetic adjustment method is to set a magnetic conductive block in the rotor assembly, which can move radially between positions close to and far from the permanent magnet, thereby changing the magnetic field distribution of the rotor assembly. By adjusting the position of its radial movement, the rotor magnetic field can be actively and controllably adjusted. However, the internal space of the rotor assembly is limited, and how to set a mechanism for driving the movement of the magnetic conductive block in it to accurately adjust the position of the magnetic conductive block has become an urgent problem to be solved. Summary of the invention

[0005] The present application mainly provides a rotor assembly, a permanent magnet synchronous motor and a vehicle. Various aspects involved in the embodiments of the present application are introduced below.

[0006] In a first aspect, a rotor assembly is provided, comprising a rotor core having a plurality of permanent magnet slots uniformly distributed along the circumferential direction; permanent magnets arranged in the permanent magnet slots; a plurality of magnetic conductive blocks arranged corresponding to the plurality of permanent magnet slots; a cam mechanism comprising a plurality of pins and a cam plate, the plurality of pins being respectively connected to the plurality of magnetic conductive blocks, the cam plate having a plurality of cam slots arranged corresponding to the plurality of pins, the pins being movably connected to the cam slots in a limited manner, and the cam plate being capable of rotating along the circumferential direction to drive the magnetic conductive blocks to move radially 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.

[0007] According to the above technical means, a cam mechanism is set in the rotor assembly, and the cam groove determines the different positions of the pins. When the cam mechanism drives the magnetic block to move radially in the rotor core, the topological structure of the rotor magnetic field is changed, thereby achieving the purpose of adjusting the air gap magnetic field strength of the rotor assembly.

[0008] In some embodiments, the cam groove includes at least one moving segment and at least one rest segment; when the pin shaft moves in the moving segment, the magnetic block moves along the radial direction toward or away from the permanent magnet slot; when the pin shaft moves in the rest segment, the magnetic block remains stationary along the radial direction.

[0009] According to the above technical means, a rest section is provided in the cam groove. When the pin shaft is located in the rest section, the cam mechanism can maintain the external force without being subjected to the external force, thereby reducing the overall energy consumption of the rotor assembly.

[0010] In some embodiments, the generatrix of the rest segment is an arc, and the center of the arc coincides with the rotation center of the cam disc.

[0011] According to the above technical means, multiple rest segments are set in the cam groove, so that the magnetic block can have multiple transient stable positions during the movement process. At this position, the air gap magnetic field strength of the rotor assembly remains unchanged. This technical solution can facilitate segmented control of the magnetic field strength.

[0012] In some embodiments, the cam groove includes a plurality of the rest segments, and the diameters of the arcs on which the generatrixes of the plurality of rest segments lie are different.

[0013] In some embodiments, the rotor assembly further includes a driving unit for driving the cam plate to rotate along the circumferential direction.

[0014] In some embodiments, the rotor assembly also includes a displacement sensor and a control unit; the displacement sensor is used to determine the position of the magnetic block; the control unit is connected to the displacement sensor and the drive unit, and is used to determine the air gap magnetic field strength of the rotor assembly according to the position of the magnetic block, and, according to the air gap magnetic field strength and the target strength value, control the drive unit to drive the cam plate to rotate and adjust the position of the magnetic block to adjust the air gap magnetic field strength to the target strength value.

[0015] According to the above technical means, a sensor is used to detect the radial position of the magnetic block to determine the main magnetic field strength, and then adjustment is made based on the main magnetic field strength, so that the magnetic field strength of the rotor assembly can be measured and the adjustment process can be controlled.

[0016] In some embodiments, the rotor assembly includes two cam mechanisms, which are axially arranged at both ends of the magnetic conductive block, and the two cam plates rotate synchronously to drive the magnetic conductive block to move between the first position and the second position.

[0017] According to the above technical means, two cam mechanisms are symmetrically arranged at two ends of the magnetic conductive block, and the two cam mechanisms work together to drive the magnetic conductive block to move, thereby preventing the magnetic conductive block from tilting due to uneven force.

[0018] In some embodiments, the rotor assembly further comprises a connecting shaft for connecting the two cam plates so that the two cam plates rotate synchronously.

[0019] According to the above technical means, the two cam discs are rotated synchronously by using a connecting shaft, and the cam mechanisms on both sides are driven to move synchronously by using the same driving unit, thereby preventing the magnetic conductive block from tilting when moving.

[0020] In some embodiments, the cam mechanism further includes a plurality of pull rods, the pull rods are inserted into the magnetic conductive block along the axial direction, and the pin shaft is provided at at least one end of the pull rod along the axial direction.

[0021] According to the above technical means, a pull rod is inserted into the magnetic conductive block, and a pin is set at the end of the pull rod, which can simplify the manufacturing and assembly process, reduce the amount of materials with high saturation magnetic induction intensity, and reduce costs.

[0022] In a second aspect, a permanent magnet synchronous motor is provided, comprising a stator assembly and a rotor assembly as described in the first aspect.

[0023] In a third aspect, a vehicle is provided, comprising the rotor assembly as described in the first aspect, or the permanent magnet synchronous motor as described in the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of a rotor assembly provided in an embodiment of the present application;

[0025] Figure 2 It is a structural schematic diagram of the rotor assembly when the pin shaft is located in the first motion section of the cam groove;

[0026] Figure 3 It is a structural schematic diagram of the rotor assembly when the pin shaft is located at the first resting section of the cam groove;

[0027] Figure 4 It is a schematic diagram of the structure of the rotor assembly when the pin shaft is located in the second motion section of the cam groove. DETAILED DESCRIPTION

[0028] The embodiments of the present application provide a rotor assembly, a permanent magnet synchronous motor and a vehicle. The technical solution of the present application is further specifically described below through the embodiments and in combination with the accompanying drawings. In the specification, the same or similar figure numbers indicate the same or similar parts. The following description of the implementation mode of the present application with reference to the accompanying drawings is intended to explain the overall concept of the present application and should not be construed as a limitation on the present application.

[0029] The permanent magnet synchronous motor (PMSM) is mainly composed of a stator assembly, a rotor assembly, a motor housing, etc. The stator assembly includes a stator core and a stator winding wound thereon. When a three-phase current is passed through the stator winding, a rotating magnetic field is generated. The rotating magnetic field interacts with the permanent magnetic field excited by the permanent magnet in the rotor assembly to provide torque for the rotor assembly.

[0030] Permanent magnet synchronous motors have a series of advantages such as small size, low weight, and high power density. They can output large torque at low speeds and have excellent low-speed performance. At the same time, my country is rich in rare earth mineral resources, and the manufacturing cost of permanent magnet synchronous motors is low. This makes permanent magnet synchronous motors widely used in electric vehicles, high-speed railways, urban rail transit, aerospace, and industrial production.

[0031] The air gap magnetic field of the permanent magnet synchronous motor is difficult to adjust, resulting in a narrow constant power area and limited width operation. In order to solve this problem, magnetic field weakening control (also known as magnetic field adjustment) can be used to increase the speed.

[0032] The motor magnetic adjustment methods in the related art include AC pulse magnetic adjustment, DC pulse magnetic adjustment and mechanical magnetic adjustment.

[0033] Among them, the AC pulse magnetization method is to apply a direct-axis charging / demagnetizing pulse current to the stator armature winding to realize the magnetization / demagnetization of the permanent magnet, thereby achieving the purpose of adjusting the air gap magnetic density and widening the operation of the motor.

[0034] The DC pulse magnetic modulation method is to set an additional DC magnetic modulation winding dedicated to magnetic modulation on the stator or rotor of the motor to realize the charging / demagnetization of the permanent magnet, or to directly use the motor armature winding to apply the magnetic modulation current.

[0035] The mechanical magnetic adjustment method is to change the magnetic field distribution of the main magnetic circuit of the motor by adding a mechanical mechanism in the stator or rotor, so as to adjust the air gap magnetic density of the motor. The mechanical structure can be, for example, a plurality of slots in the rotor core, and permanent magnets with the same polarity are arranged at both ends of the slots; when the motor speed increases, the permanent magnets that are not fixed will move closer to the air gap under the action of centrifugal force, so that the magnetic resistance of the main magnetic pole leakage magnetic circuit is reduced, the leakage magnetic flux is increased, and the magnetic flux passing through the air gap is reduced, so as to achieve the purpose of reducing the air gap magnetic density when the motor runs at high speed.

[0036] Among the various methods mentioned above, the weakening magnetic current during DC or AC pulse magnetic modulation will lead to higher copper loss, which will reduce the high-speed operation efficiency of the permanent magnet synchronous motor; at the same time, this method also requires the addition of additional components in the circuit part, resulting in increased costs. The existing mechanical magnetic modulation methods are mostly passive adjustments, that is, they cannot actively control their weak magnetic ability, and the weak magnetic ability of this method is limited, and it cannot achieve the expected effect.

[0037] In order to achieve deeper active adjustment of the permanent magnet magnetic field of the permanent magnet synchronous motor's rotor, a feasible way is to set a movable magnetic conductive block in the rotor assembly. The magnetic conductive block is made of a material with high saturation magnetic induction intensity and can move radially between positions close to and away from the permanent magnet, thereby changing the magnetic field distribution of the rotor assembly. By adjusting its radial movement position, active and controllable adjustment of the rotor magnetic field can be achieved.

[0038] However, the internal space of the rotor assembly is limited, and how to set a mechanism therein for driving the magnetic block to move so as to accurately adjust the position of the magnetic block has become an urgent problem to be solved.

[0039] In view of the above problems, the embodiments of the present application provide a rotor assembly, a permanent magnet synchronous motor and a vehicle. The technical solution of the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings.

[0040] Figure 1 is a schematic structural diagram of the rotor assembly 10 provided in an embodiment of the present application.

[0041] like Figure 1 As shown, the rotor assembly 10 in the embodiment of the present application includes a rotor core 11 , a permanent magnet 12 , a magnetic conductive block 13 and a cam mechanism 14 .

[0042] The rotor core 11 has a plurality of permanent magnet slots 111 uniformly distributed along the circumferential direction. It should be noted that the circumferential direction mentioned here refers to the circumferential direction surrounding the axial direction of the rotor core 11, and the axial direction refers to the direction where the central axis of the rotor assembly 10 is located.

[0043] The permanent magnet 12 is disposed in the permanent magnet slot 111. The permanent magnet 12 mentioned in the embodiment of the present application refers to a magnet that can maintain magnetism for a long time, such as natural magnetite (ferromagnetic ore) and artificial magnet steel (such as iron-nickel-cobalt magnet steel, neodymium-iron-boron magnet steel, etc.).

[0044] The magnetic conductive blocks 13 are arranged corresponding to the permanent magnet slots 111 , and each magnetic conductive block 13 is arranged radially on a side of the corresponding permanent magnet slot 111 close to the rotating shaft 15 .

[0045] The cam mechanism 14 includes a plurality of pins 141 and a cam plate 142 .

[0046] The plurality of pins 141 are respectively connected to the plurality of magnetic conductive blocks 13. The pins 141 and the magnetic conductive blocks 13 may be fixedly connected by welding, riveting, bonding or threaded connection, and the embodiment of the present application does not specifically limit the connection method.

[0047] The cam plate 142 has a plurality of cam grooves 1421 disposed corresponding to the plurality of pins 141. The plurality of cam grooves 1421 are arranged at equal intervals along the rotation center of the cam plate 142.

[0048] The pin shaft 141 is movably connected in a limited position in the cam groove 1421. The side wall of the cam groove 1421 can limit the pin shaft 141, and the movement of the pin shaft 141 is limited to sliding in the cam groove 142 along the extension direction of the cam groove 1421.

[0049] The cam plate 142 can rotate in the circumferential direction, so that the pin shaft 141 drives the magnetic conductive block 13 to move radially 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.

[0050] According to the principle of minimum magnetic resistance, the magnetic field will be distributed along the direction with smaller magnetic resistance, and the magnetic resistance of the magnetic conductive block 13 is much smaller than that of air. Therefore, in the rotor assembly 10, the magnetic flux lines of the permanent magnetic field generated by the permanent magnet 12 will preferentially pass through the magnetic conductive block 13; when the magnetic conductive block 13 moves under the action of the cam mechanism 14, the magnetic field distribution in the rotor assembly 10 changes accordingly.

[0051] More specifically, when the magnetic block 13 moves to the first position close to the permanent magnet slot 111, the permanent magnetic field of the rotor will gather toward the position of the magnetic block 13; in other words, when the magnetic block 13 is located at the first position close to the permanent magnet slot 111, the permanent magnetic field of the rotor does not pass through the air gap of the rotor assembly 10; in other words, when the magnetic block 13 is located at the first position close to the permanent magnet slot 111, the air gap magnetic field of the rotor assembly 10 is 0.

[0052] When the magnetic block 13 moves to the second position away from the permanent magnet slot 111, an air gap is formed between the magnetic block 13 and the rotor core, and the magnetic resistance at this position is relatively large. The permanent magnetic field of the permanent magnet 12 will preferentially pass through the rotor core 11 with a smaller magnetic resistance, and at this time, the magnetic field strength of the air gap magnetic field of the rotor assembly 10 is relatively large.

[0053] When the magnetic block 13 is at different positions between the first position and the second position, the width of the air gap between the magnetic block 13 and the rotor core 11 is different, resulting in different effects of the magnetic block 13 on the air gap magnetic field of the rotor assembly 10; that is, by adjusting the position of the magnetic block 13, the permanent magnetic field of the rotor assembly 10 can be adjusted.

[0054] According to the above technical means, a cam mechanism is set in the rotor assembly, and the cam groove determines the different positions of the pins. When the cam mechanism drives the magnetic block to move radially in the rotor core, the topological structure of the rotor magnetic field is changed, thereby achieving the purpose of adjusting the air gap magnetic field strength of the rotor assembly.

[0055] In some embodiments, the magnetic conductive block 13 is made of a material with high saturation magnetic flux density, such as 1J22 alloy, 2J10 alloy, 1J85 alloy, etc., and its saturation magnetic flux density can reach 2.4T or above, which is much greater than the saturation magnetic flux density of air and silicon steel sheets. The magnetic conductive block 13 made of a material with high saturation magnetic flux density can achieve the maximum adjustment requirement for the magnetic flux of the rotor assembly 10 at the minimum size.

[0056] In some embodiments, the cam slot 1421 includes at least one moving segment and at least one rest segment. When the pin shaft 141 moves in the moving segment, the magnetic block 13 moves radially toward or away from the permanent magnet slot 111; when the pin shaft 141 moves in the rest segment, the magnetic block 13 remains stationary radially.

[0057] Figure 2-Figure 4 1 is a schematic diagram of the partial structure of the rotor assembly provided in an embodiment of the present application, which shows the distribution of the magnetic blocks when the pin shaft 141 is located at different positions of the cam groove 1421. Figure 2-Figure 4 The cam groove 1421 shown in FIG. 1 has a first motion segment 1421A, a second motion segment 1421C, and a first rest segment 1421B between the first motion segment 1421A and the second motion segment 1421C.

[0058] Figure 2-Figure 4 The cam plate 142 is shown to rotate in the counterclockwise direction (indicated by the arrow in the figure) until the pin shaft 141 is located in the first moving section 1421A, the first resting section 1421B and the second moving section 1421C respectively.

[0059] like Figure 2 As shown, in the initial state, the pin 141 is located at the end of the cam slot 1421 away from the rotating shaft 15 of the rotor assembly 10, or in other words, the pin 141 is located at the end of the first moving section 1421A away from the first resting section 1421B. At this time, the magnetic block 13 is located at the first position close to the permanent magnet slot 111. In this case, the air gap magnetic field strength of the rotor assembly 10 is minimum.

[0060] When the cam plate 142 rotates counterclockwise to Figure 3 In the state shown in FIG. 1 , the pin 141 is located at the first resting section 1421B, and the magnetic block 13 is located at the middle position between the first position and the second position. Figure 3When the pin 141 rotates within the range of the first angle α shown, the radial positions of the pin 141 and the magnetic conductive block 13 connected to the pin 141 will not change; this also means that, in this case, the air gap magnetic field strength of the rotor assembly 10 remains constant. At the same time, when the pin 141 is located in the first resting section 1421B, the cam plate 142 can be maintained at this position without being driven by external force.

[0061] The cam plate 142 continues to rotate in the direction shown in the figure until Figure 4 In the state shown, the pin 141 is located at the end of the cam slot 1421 close to the rotating shaft 15; or in other words, the pin 141 is located at the end of the second moving section 1421C away from the first resting section 1421B. In this case, the magnetic block 13 is moved to the second position away from the permanent magnet slot 111, and the air gap magnetic field strength of the rotor assembly 10 is the maximum.

[0062] According to the above technical means, a rest section is provided in the cam groove. When the pin shaft is located in the rest section, the cam mechanism can maintain the external force without being subjected to the external force, thereby reducing the overall energy consumption of the rotor assembly.

[0063] In some embodiments, continue to refer to Figure 3 In order to prevent the radial position of the pin 141 from changing when the rest section moves, the rest section (e.g. Figure 3 The generatrix of the first rest section 1421B) is set as an arc, and the center of the arc coincides with the rotation center of the cam plate 142.

[0064] In some embodiments, the cam slot 1421 may include multiple resting sections, and the diameters of the arcs where the generatrixes of the multiple resting sections are located are different. When the pin shaft 141 is located at different resting sections, the magnetic block 13 is at different positions, corresponding to different air gap magnetic field strengths of the rotor assembly 10.

[0065] The embodiment of the present application does not limit the specific positions of the above-mentioned multiple rest segments. The rest segments can be set at any position in the cam groove, and the positions of the multiple rest segments can be determined according to the requirements for the air gap magnetic field strength.

[0066] The embodiment of the present application does not limit the number of the plurality of rest segments, which may be two or more. For example, three rest segments may be provided in the cam groove, corresponding to magnetic field strengths of 25%, 50% and 75% of the maximum magnetic field strength, respectively.

[0067] According to the above technical means, multiple rest segments are set in the cam groove, so that the magnetic block can have multiple transient stable positions during the movement process. At this position, the air gap magnetic field strength of the rotor assembly remains unchanged. This technical solution can facilitate segmented control of the magnetic field strength.

[0068] In some embodiments, the rotor assembly 10 includes two cam mechanisms, which are the cam mechanisms 14 in any of the foregoing embodiments. The two cam mechanisms are axially arranged at both ends of the magnetic block 13, and the cam plates 142 in the two cam mechanisms rotate synchronously, so that the pin shafts 141 at both ends of the magnetic block 13 can simultaneously drive the magnetic block 13 to move.

[0069] According to the above technical means, two cam mechanisms are symmetrically arranged at two ends of the magnetic conductive block, and the two cam mechanisms work together to drive the magnetic conductive block to move, thereby preventing the magnetic conductive block from tilting due to uneven force.

[0070] In some embodiments, the cam mechanism further includes a plurality of pull rods, which are axially inserted into the magnetic conductive block, and a pin shaft 141 is provided at at least one end of the pull rod along the axial direction.

[0071] According to the above technical means, a pull rod is inserted into the magnetic conductive block, and a pin is set at the end of the pull rod, which can simplify the manufacturing and assembly process, reduce the amount of materials with high saturation magnetic induction intensity, and reduce costs.

[0072] In some embodiments, the rotor assembly further comprises a driving unit for driving the cam plate to rotate in the circumferential direction. The driving unit may be, for example, an electric motor or a hydraulic motor.

[0073] As an implementation method, the driving unit may be an outer rotor motor, which is arranged between the rotating shaft of the rotor assembly and the cam plate. Specifically, the stator of the outer rotor motor is sleeved on the rotating shaft and fixedly connected to the rotating shaft, and the cam plate is sleeved on the rotor of the outer rotor motor and rotates in the circumferential direction under the drive of the rotor.

[0074] In some embodiments, the rotor assembly further comprises a connecting shaft, which is arranged axially and is used to connect the cam plates in the two cam mechanisms at both ends of the magnetic conductive 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.

[0075] According to the above technical means, the two cam discs are rotated synchronously by using a connecting shaft, and the cam mechanisms on both sides are driven to move synchronously by using the same driving unit, thereby preventing the magnetic conductive block from tilting when moving.

[0076] In some embodiments, the rotor assembly 10 further includes a sensor and a control unit.

[0077] The sensor is used to determine the position of the magnetic conductive block 13. There are multiple methods for determining the position of the magnetic conductive block 13 according to different settings of the sensor.

[0078] As an implementation method, the sensor can be a distance sensor, which can be radially arranged on one side of the magnetic block 13, for example, on the side of the magnetic block 13 close to the rotating shaft 15, and is used to measure the distance between the end of the sensor and the end face of the magnetic block 13 close to the rotating shaft 15, and determine the position of the magnetic block 13 based on the distance.

[0079] As another implementation, the sensor may also be a sensor for measuring rotation angle, such as a Hall sensor, which may be used to measure the rotation angle of the cam plate 142 and determine the position of the magnetic block 13 according to the change in the rotation angle.

[0080] The control unit is connected to the sensor and the drive unit, and is used to determine the air gap magnetic field strength of the rotor assembly 10 according to the position of the magnetic block 13. According to the air gap magnetic field strength and the target magnetic field strength value, the drive unit is controlled to drive the cam plate 142 to rotate, so that the pin shaft 141 drives the magnetic block 13 to adjust its position, so as to adjust the air gap magnetic field strength of the rotor assembly 10 to the target magnetic field strength value.

[0081] It should be understood that the position of the magnetic block 13 and the air gap magnetic field strength value usually have a one-to-one correspondence. When the position of the magnetic block 13 is adjusted according to the target magnetic field strength value, the target position of the magnetic block 13 can be determined based on the pre-established mapping relationship between the position of the magnetic block 13 and the magnetic field strength; then, the target stroke of the drive unit is determined based on the deviation between the target position and the current position of the magnetic block 13; and based on the target stroke of the drive unit, a control signal is sent to the drive unit to move the magnetic block 13 to the target position.

[0082] According to the above technical means, a sensor is used to detect the radial position of the magnetic block to determine the main magnetic field strength, and then adjustment is made based on the main magnetic field strength, so that the magnetic field strength of the rotor assembly can be measured and the adjustment process can be controlled.

[0083] An embodiment of the present application further provides a permanent magnet synchronous motor, including a rotor assembly and a stator assembly, wherein the rotor assembly is the rotor assembly 10 described in any of the above embodiments.

[0084] 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 drive devices, automation equipment, fans, pumps, compressors, machine tools, robots, and vehicles.

[0085] The vehicles may include land vehicles, air vehicles, water vehicles, industrial equipment, agricultural equipment or recreational equipment, etc.

[0086] Exemplarily, the water transportation vehicle may be a hovercraft, a motorboat, a motorboat, a fishing boat, a cruise ship, a sailboat, a yacht or other vessel.

[0087] The air transportation means may be an airplane, and the land transportation means may be a vehicle.

[0088] An embodiment of the present application also provides a vehicle, which includes the rotor assembly 10 or the permanent magnet synchronous motor in any of the above embodiments.

[0089] In some embodiments, the vehicle is a transportation vehicle. Exemplarily, the vehicle is one of a commercial vehicle, a passenger car, a motorcycle, a flying car, and a train.

[0090] In some embodiments, the vehicle is an industrial vehicle or an engineering vehicle. Exemplarily, the vehicle is one of a forklift, a trailer, a tractor, an excavator, a bulldozer, and a crane.

[0091] In some embodiments, the vehicle may be an electric vehicle or a fuel vehicle, wherein the vehicle is exemplarily one of a pure electric vehicle / battery electric vehicle (PEV / BEV), a hybrid electric vehicle (HEV), a range extended electric vehicle (REEV) and a plug-in hybrid electric vehicle (PHEV).

[0092] In some embodiments, the vehicle may also be agricultural equipment (such as a lawn mower, a harvester, etc.), amusement equipment, a toy vehicle, etc.

[0093] In some embodiments, the vehicle may also be a high-speed railway train, an EMU train, an urban rail transit vehicle, etc.

[0094] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0095] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0096] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0097] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0098] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0099] The above is only a preferred embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A rotor assembly, characterized in that: include: A rotor core having a plurality of permanent magnet slots uniformly distributed along the circumferential direction; A permanent magnet is disposed in the permanent magnet slot; A plurality of magnetic conductive blocks are arranged corresponding to the plurality of permanent magnet slots; The cam mechanism comprises a plurality of pins and a cam plate, wherein the plurality of pins are respectively connected to the plurality of magnetic conductive blocks, the cam plate has a plurality of cam grooves corresponding to the plurality of pins, and the pins can be movably connected to the cam grooves in a limited manner; The cam plate can rotate along the circumferential direction to drive the magnetic conductive block to move radially between a first position close to the permanent magnet slot and a second position away from the permanent magnet slot to adjust the magnetic field distribution of the rotor assembly.

2. The rotor assembly according to claim 1, characterized in that: The cam groove includes at least one moving segment and at least one rest segment; When the pin moves in the motion section, the magnetic conductive block moves along the radial direction toward or away from the permanent magnet slot; When the pin shaft moves in the resting state, the magnetic conductive block remains stationary along the radial direction.

3. The rotor assembly according to claim 2, characterized in that: The generatrix of the rest section is an arc, and the center of the arc coincides with the rotation center of the cam disc.

4. The rotor assembly according to claim 3, characterized in that: The cam groove includes a plurality of rest segments, and the diameters of the arcs where the generatrixes of the plurality of rest segments are located are different.

5. The rotor assembly according to claim 1, characterized in that: It also includes a driving unit for driving the cam plate to rotate along the circumferential direction.

6. The rotor assembly according to claim 5, characterized in that Also includes a displacement sensor and a control unit; The displacement sensor is used to determine the position of the magnetic block; The control unit is connected to the displacement sensor and the driving unit, and is used to determine the air gap magnetic field strength of the rotor assembly according to the position of the magnetic block, and, according to the air gap magnetic field strength and the target strength value, control the driving unit to drive the cam plate to rotate and adjust the position of the magnetic block to adjust the air gap magnetic field strength to the target strength value.

7. The rotor assembly according to any one of claims 1 to 6, characterized in that: The rotor assembly includes two cam mechanisms, which are arranged at two ends of the magnetic conductive block along the axial direction of the rotor assembly. The two cam plates rotate synchronously to drive the magnetic conductive block to move between the first position and the second position.

8. The rotor assembly according to claim 7, characterized in that It also includes a connecting shaft for connecting the two cam plates so that the two cam plates rotate synchronously.

9. The rotor assembly according to any one of claims 1 to 6, characterized in that: The cam mechanism further comprises a plurality of pull rods, wherein the pull rods are inserted into the magnetic conductive block along the axial direction of the rotor assembly, and the pin shaft is disposed at at least one end of the pull rods along the axial direction.

10. A permanent magnet synchronous motor, characterized in that: The invention comprises a stator assembly and a rotor assembly according to any one of claims 1 to 9.

11. A vehicle, characterized in that: The vehicle comprises: a rotor assembly as claimed in any one of claims 1 to 9, or a permanent magnet synchronous motor as claimed in claim 10.

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