Permanent magnet electric motor, electric motor rotor system, and manufacturing method therefor

Abstract

Provided in the embodiments of the present disclosure are a permanent magnet electric motor, an electric motor rotor system, and a manufacturing method therefor, which relate to the technical field of permanent magnet electric motors. The electric motor rotor system comprises a support device and a rotor assembly, wherein the support device has a first support rotation center and a second support rotation center that are spaced apart; and the rotor assembly is rotatably connected to the support device at the first support rotation center and the second support rotation center, respectively, and rotates around the line connecting the first support rotation center and the second support rotation center, the distance between the first support rotation center and the center of gravity of the rotor assembly is a first distance, the distance between the second support rotation center and the center of gravity of the rotor assembly is a second distance, and the first distance is equal to the second distance.

Description

Permanent magnet motor, motor rotor system and manufacturing method thereof

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure is based on the Chinese patent application with application number 202311626223.4, application date November 30, 2023, and invention name “Permanent magnet motor, motor rotor system and manufacturing method thereof”, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby introduced into this disclosure as a reference. Technical Field

[0003] The present disclosure relates to the field of permanent magnet motors, and in particular to a permanent magnet motor, a motor rotor system, and a manufacturing method thereof. Background Art

[0004] With the continuous development of the motor industry, motor speeds are also increasing. High-speed permanent magnet motors are increasingly used in air compressors, energy storage flywheels, high-speed pumps, and other fields. High-speed permanent magnet motors offer many advantages, such as compact size and high power density. Due to their very high speed, the linear velocity of the rotor surface can reach 200 m / s when the motor rotates. However, the rotor structure of traditional permanent magnet motors struggles to meet the requirements of high-speed motors. The bearing capacity provided by the support devices on both sides often differs, with one side having a higher bearing capacity, which can reduce the reliability of the permanent magnet motor during high-speed operation.

[0005] Summary of the Invention

[0006] In view of this, the embodiments of the present disclosure hope to provide a permanent magnet motor, a motor rotor system and a manufacturing method thereof, which are conducive to making the bearing capacity provided by the support devices on both sides as consistent as possible when the permanent magnet motor runs at high speed.

[0007] To achieve the above objectives, the technical solution of the embodiment of the present disclosure is implemented as follows:

[0008] An embodiment of the present disclosure provides a motor rotor system, comprising:

[0009] A support device having a first support rotation center and a second support rotation center arranged at intervals;

[0010] The rotor assembly is rotatably connected to the support device at the first support rotation center and the second support rotation center, respectively. The rotor assembly rotates around the line connecting the first support rotation center and the second support rotation center. The distance between the first support rotation center and the center of gravity of the rotor assembly is a first distance, and the distance between the second support rotation center and the center of gravity of the rotor assembly is a second distance. The first distance is equal to the second distance.

[0011] In one embodiment, a midpoint of a line connecting the first support rotation center and the second support rotation center coincides with the center of gravity of the rotor assembly.

[0012] In one embodiment, the support device includes two support members arranged at an interval, the first support rotation center is formed on one of the support members, and the second support rotation center is formed on the other support member.

[0013] In one embodiment, the rotor assembly includes:

[0014] A working component having a receiving cavity;

[0015] The permanent magnet component is installed in the accommodating cavity, and the permanent magnet component is a solid structure.

[0016] In one embodiment, the permanent magnet assembly includes a plurality of stacked permanent magnets and an insulating layer disposed between two adjacent permanent magnets, and the permanent magnets are configured in a disk shape.

[0017] In one embodiment, the working component includes:

[0018] jacket;

[0019] A shaft assembly is provided at both ends of the sleeve along the axial direction, and the sleeve and the shaft assembly are surrounded by the accommodating cavity.

[0020] In one embodiment, the sheath is welded to the shaft assembly.

[0021] In one embodiment, the permanent magnet assembly is located in the sheath, and the sheath and the permanent magnet assembly are interference fit.

[0022] In one embodiment, the shaft assembly has a weight-reducing hole, and the weight-reducing hole is formed at one end of the shaft assembly close to the permanent magnet assembly.

[0023] In one embodiment, the shaft assembly comprises:

[0024] a shaft body, wherein the lightening hole is formed in the shaft body;

[0025] A sealing cover is provided between the shaft body and the permanent magnet assembly to close the weight-reducing hole.

[0026] In one embodiment, the shaft assembly further has an exhaust hole connected to the outside world, so as to connect the weight-reducing hole with the outside world.

[0027] In one embodiment, there are at least two exhaust holes, and the exhaust holes are arranged in pairs along the radial direction of the shaft assembly.

[0028] In one embodiment, the exhaust hole is arranged to be inclined along the radial direction of the shaft assembly, and the inclination direction of the exhaust hole is the same as the rotation direction of the shaft assembly.

[0029] In one embodiment, the working component further includes a locking member and a displacement sensor mounted on the locking member, wherein the locking member is disposed at an end of the shaft assembly away from the permanent magnet assembly, and the displacement sensor is used to monitor the axial and radial motion trajectories of the motor rotor system.

[0030] The present disclosure also provides a permanent magnet motor, comprising:

[0031] The motor rotor system according to any one of the preceding embodiments;

[0032] stator core.

[0033] In one embodiment, the axial length of the permanent magnet assembly is greater than the axial length of the stator core.

[0034] The present disclosure also provides a method for manufacturing a motor rotor system, wherein the rotor assembly includes a working component and a permanent magnet assembly, wherein the working component includes a sleeve and a shaft assembly. The manufacturing method includes:

[0035] Using the outer circumference of the permanent magnet assembly as a radial positioning reference, the sheath is sleeved on the permanent magnet assembly;

[0036] The position of the shaft assembly relative to the sleeve along the axial direction of the sleeve is determined by taking the sleeve as an axial positioning reference.

[0037] In one embodiment, the permanent magnet assembly specifically includes:

[0038] A plurality of disc-shaped permanent magnets are bonded together to form the cylindrical permanent magnet assembly.

[0039] Effects of the Invention

[0040] In the motor rotor system provided by the embodiment of the present disclosure, the distance from the center of gravity of the rotor assembly to the first support rotation center is equal to the distance from the rotor assembly to the second support rotation center, so that the bearing capacity of the first support rotation center and the second support rotation center are as consistent as possible, which is beneficial to reducing the risk of unstable operation caused by unbalanced bearing capacity of the bearings at both ends when the rotor assembly rotates at high speed, and improving the reliability of high-speed rotation of the rotor assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIG1 is a schematic diagram of a permanent magnet motor according to an embodiment of the present disclosure;

[0042] FIG2 is a schematic diagram of a shaft body according to an embodiment of the present disclosure;

[0043] FIG3 is a radial cross-sectional view of the shaft body at the exhaust hole AA in FIG2 ;

[0044] FIG4 is a schematic diagram of a locking member in an embodiment of the present disclosure;

[0045] FIG5 is a flow chart of a method for manufacturing a motor rotor system according to an embodiment of the present disclosure.

[0046] Explanation of the accompanying symbols: 1. Rotor assembly; 1a. Center of gravity; 1b. First support rotation center; 1c. Second support rotation center; 10. Working part; 11. Permanent magnet assembly; 111. Permanent magnet; 12. Shaft assembly; 121. Shaft body; 1211. External hexagonal square head; 122. Cover; 121a. Weight reduction hole; 121b. Exhaust hole; 13. Sleeve; 15. Locking piece; 161. Low-pressure side impeller; 162. High-pressure side impeller; 17. Thrust plate; 2. Support device; 21. Support member; 3. Stator core. DETAILED DESCRIPTION

[0047] The following embodiments of the present disclosure are further described in detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present disclosure but are not intended to limit the scope of the present disclosure.

[0048] In the description of the embodiments of the present disclosure, it should be noted that the terms "circumferential," "axial," and "radial" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the embodiments of the present disclosure and to simplify the description. They are not intended to indicate or imply that the devices or elements referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the embodiments of the present disclosure. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0049] In the description of this specification, the description with reference to the term "some embodiments" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment are included in at least one embodiment of the presently disclosed embodiments. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0050] Related technologies use independent long screws for positioning or threaded assembly in rotor structures, which can lead to significant positional deviations between components on both sides. This can lead to localized bearing damage and heating during high-speed operation, excessive axial force on the rotor, and poor operational stability due to uneven force on both sides.

[0051] In view of this, referring to FIG. 1 , an embodiment of the present disclosure provides a motor rotor system, which includes a support device 2 and a rotor assembly 1 .

[0052] The support device 2 has a first support rotation center 1b and a second support rotation center 1c arranged at intervals. The rotor assembly 1 is rotationally connected to the support device 2 at the first support rotation center 1b and the second support rotation center 1c, respectively, and the rotor assembly 1 rotates about the line connecting the first support rotation center 1b and the second support rotation center 1c.

[0053] Among them, the distance between the first support rotation center 1b and the center of gravity 1a of the rotor assembly 1 is a first distance, and the distance between the second support rotation center 1c and the center of gravity 1a of the rotor assembly 1 is a second distance, and the first distance is equal to the second distance.

[0054] In the embodiment of the present disclosure, since the first distance and the second distance are equal, the bearing capacities of the first support rotation center 1b and the second support rotation center 1c on the rotor assembly 1 are substantially equal in magnitude and roughly the same in direction, and the force on the rotor assembly 1 is relatively uniform, which is beneficial to improving the stability of the rotor assembly 1 during high-speed rotation and reducing local damage and heat generation of the bearings.

[0055] In one embodiment, referring to FIG. 1 , the midpoint of a line connecting the first support rotation center 1 b and the second support rotation center 1 c coincides with the center of gravity 1 a of the rotor assembly 1 .

[0056] In the disclosed embodiment, while the first distance and the second distance are equal, the center of gravity 1a of the rotor assembly 1 is on the line connecting the first support rotation center 1b and the second support rotation center 1c, so that the centrifugal force exerted on the rotor assembly 1 during rotation is smaller, which is beneficial to improving the stability and reliability of the rotor assembly 1 during high-speed rotation.

[0057] It is understandable that the position of the center of gravity 1a of the rotor assembly 1 is not limited. For example, the midpoint of the line connecting the first support rotation center 1b and the second support rotation center 1c and the center of gravity 1a of the rotor assembly 1 can be staggered.

[0058] In one embodiment, referring to FIG. 1 , the support device 2 includes two support members 21 spaced apart from each other. A first support rotation center 1 b is formed on one of the support members 21 , and a second support rotation center 1 c is formed on the other support member 21 .

[0059] In the embodiment of the present disclosure, the distance between the two support members 21 can be arranged according to actual needs. The arrangement of the two support members 21 is more flexible and more convenient for maintenance.

[0060] It is understood that the type of support member 21 is not limited herein. Exemplarily, the support member 21 is a bearing, spaced apart on both sides of the rotor assembly 1 along the axial direction. Exemplarily, the support member 21 is a supporting structure, and the rotor assembly 1 is mounted on the supporting structure.

[0061] In one embodiment, referring to FIG1 , a rotor assembly 1 includes a working component 10 and a permanent magnet assembly 11 . The working component 10 has a receiving cavity, and the permanent magnet assembly 11 is a solid structure and is installed in the receiving cavity of the working component 10 .

[0062] In the embodiment of the present disclosure, the solid structure of the permanent magnet component 11 improves the rigidity of the rotor assembly 1 and can withstand the centrifugal force caused by a higher rotation speed. Therefore, at the same rotation speed, the protective cover required for the solid structure of the permanent magnet component 11 is thinner, which reduces the difficulty of assembly. At the same time, the solid structure of the permanent magnet component 11 can avoid the generation of axial force on the rotor assembly 1 that causes axial eccentricity of the rotor assembly 1, reduces the axial bearing capacity of the bearing, reduces heat generation, and is conducive to improving the stability of high-speed rotation of the rotor and the anti-demagnetization ability of the permanent magnet component 11. In addition, the solid structure of the permanent magnet component 11 has a higher magnetic flux density. Therefore, at the same magnetic flux density, the solid cylindrical structure of the permanent magnet component 11 can reduce the length of the rotating shaft and the stator core, thereby improving the power density of the permanent magnet motor and increasing the first-order bending critical speed of the motor rotor system.

[0063] It is understood that the radial cross-sectional shape of the permanent magnet assembly 11 is not limited, and can be, for example, circular or rectangular.

[0064] In one embodiment, referring to FIG. 1 , the permanent magnet assembly 11 includes a plurality of stacked disc-shaped permanent magnets 111 and an insulating layer disposed between two adjacent permanent magnets 111 .

[0065] In the disclosed embodiment, the permanent magnet assembly 11 is formed by bonding multiple disc-shaped permanent magnets 111 with consistent magnetic field orientation in sections along the axial direction using an insulating adhesive. Since the permanent magnet assembly 11 is internally separated by insulating material, eddy current losses within the permanent magnet assembly 11 can be effectively reduced.

[0066] It is understandable that the material of the permanent magnet 111 is not limited, and it can be, for example, a neodymium iron boron permanent magnet, a samarium cobalt permanent magnet, or an aluminum nickel cobalt permanent magnet.

[0067] There is no limitation on the material of the insulating layer, as long as it meets the requirements of high strength, high insulation, and high temperature resistance.

[0068] Illustratively, the permanent magnet 111 is made of rare earth samarium cobalt 2:17 permanent magnet material and is bonded in sections along the axial direction. The thickness of each permanent magnet 111 is 7 to 10 mm, the thickness of the insulation layer is less than or equal to 0.1 mm, and the temperature resistance of the insulation layer is not less than 220°C.

[0069] 1 , the working component 10 includes a sheath 13 and a shaft assembly 12. The sheath 13 is provided with shaft assemblies 12 at both ends along the axial direction. The sheath 13 and the shaft assembly 12 enclose the working component 10 to form a receiving cavity for mounting the permanent magnet assembly 11.

[0070] In the embodiment of the present disclosure, the sleeve 13 is installed with the radial size of the permanent magnet assembly 11 as the positioning reference, and the shaft assembly 12 is connected with the sleeve 13 as the axial positioning reference, so that the basic structure formed by the working component 10 has a higher installation accuracy, which is beneficial to improving the reliability of the rotor assembly 1 during high-speed rotation.

[0071] In one embodiment, the sheath 13 is welded to the shaft assembly 12 .

[0072] In the embodiment of the present disclosure, the sheath 13 and the shaft assembly 12 can be independently processed and then welded into one body, which helps to reduce the difficulty of processing the sheath 13 and the shaft assembly 12.

[0073] For example, the sheath 13 and the shaft assembly 12 are laser welded into one piece, which makes the sheath 13 and the shaft assembly 12 easy to process and easy to assemble, and both the positional tolerance and the dimensional tolerance can be guaranteed.

[0074] In one embodiment, referring to FIG. 1 , the permanent magnet assembly 11 is located in the sheath 13 , and the permanent magnet assembly 11 and the sheath 13 are interference fit.

[0075] In the disclosed embodiment, the permanent magnet assembly 11 and the sleeve 13 are interference-fitted, and the outer peripheral surface of the permanent magnet assembly 11 is tightly fitted with the inner peripheral surface of the sleeve 13. Therefore, there is no gap between the mating surfaces of the permanent magnet assembly 11 and the sleeve 13. When the rotor assembly 1 rotates at high speed, the sleeve 13 can protect the permanent magnet assembly 11, preventing the high-speed rotating permanent magnet assembly 11 from disintegrating and failing due to centrifugal force, which is conducive to increasing the speed of the rotor assembly 1. In addition, the sleeve 13 can prevent the permanent magnet assembly 11 from being eccentric in the radial and axial directions during high-speed rotation, thereby reducing the maximum centrifugal force and unbalanced magnetic pull of the permanent magnet assembly 11, and improving the operating performance and stability of the permanent magnet motor.

[0076] In one embodiment, referring to FIG. 1 , the sheath 13 is welded to the shaft assembly 12 , and the permanent magnet assembly 11 is located in the sheath 13 . The permanent magnet assembly 11 and the sheath 13 are interference fit.

[0077] In the embodiment of the present disclosure, the permanent magnet assembly 11 and the sleeve 13 are interference fit, and the sleeve 13 and the shaft assembly 12 are welded into one, which is beneficial to improving the rigidity of the rotor assembly 1, and is also beneficial to improving the assembly accuracy of the permanent magnet assembly 11, the sleeve 13 and the shaft assembly 12, so as to reduce the risk of instability of the permanent magnet motor during high-speed operation due to low assembly accuracy.

[0078] It is understood that the material of the sheath 13 is not limited, and may be iron, cobalt, or nickel, for example. For example, the sheath 13 is made of GH4169 high-temperature nickel-based alloy with a hardness of HRC38-45.

[0079] In one embodiment, referring to FIG. 1 and FIG. 2 , the shaft assembly 12 has a lightening hole 121 a . The lightening hole 121 a is formed at one end of the shaft assembly 12 close to the permanent magnet assembly 11 .

[0080] In the embodiment of the present disclosure, the shaft assembly 12 with the weight-reducing hole 121a is lighter in weight, so the moment of inertia is smaller, the dynamic response is faster, and the load-bearing requirements for the support member 21 are lower, which is beneficial to improving the start-stop life of the shaft assembly 12.

[0081] 1 and 2 , the shaft assembly 12 includes a shaft body 121 and a cover 122 . A lightening hole 121 a is formed in the shaft body 121 ; the cover 122 is disposed between the shaft body 121 and the permanent magnet assembly 11 to seal the lightening hole 121 a .

[0082] In the disclosed embodiment, a lightening hole 121a is formed at one end of the shaft body 121 near the permanent magnet assembly 11. This hole is sealed by a cover 122, and the shaft assembly 12 is connected to the permanent magnet assembly 11 via the cover 122. If the permanent magnet assembly 11 breaks during high-speed rotation, the cover 122 can seal the broken permanent magnet assembly 11 within the accommodating cavity, preventing the broken permanent magnet assembly 11 from causing secondary damage to the permanent magnet motor.

[0083] In one embodiment, referring to FIG. 1 and FIG. 2 , the shaft body 121 is bonded to the cover 122 to close the weight-reducing hole 121 a , and the shaft assembly 12 is bonded to the permanent magnet assembly 11 through the cover 122 .

[0084] In the disclosed embodiment, cover 122 increases the bonding area between shaft assembly 12 and permanent magnet assembly 11, thereby improving bonding strength. This also prevents the risk of adhesive material leaking into lightening holes 121a due to assembly extrusion, which could cause unbalanced rotation of rotor assembly 1. This helps improve the stability of the permanent magnet motor.

[0085] It is understandable that there is no limitation on the assembly method of the shaft body 121, the cover 122 and the permanent magnet assembly 11. For example, the cover 122 is first bonded to the permanent magnet assembly 11, and then the shaft body 121 is bonded to the cover 122 to close the weight reduction hole 121a.

[0086] The material of the shaft body 121 is not limited, and may be, for example, iron, cobalt, or nickel. For example, the shaft body 121 is made of GH4169 high-temperature nickel-based alloy with a hardness of HRC38-45.

[0087] The material of the cover 122 is not limited, and may be iron, cobalt, or nickel, for example.

[0088] In one embodiment, referring to FIG. 1 to FIG. 3 , the shaft assembly 12 further has an exhaust hole 121 b communicating with the outside, so as to connect the weight-reducing hole 121 a with the outside.

[0089] In the disclosed embodiment, the exhaust hole 121b is also located on the side of the shaft body 121 close to the permanent magnet assembly 11 and is arranged radially along the shaft body 121. While further reducing the weight of the shaft body 121, when the rotor assembly 1 rotates at high speed, the gas inside the shaft body 121 that expands due to heat can be smoothly discharged to the outside.

[0090] In one embodiment, referring to FIG. 1 to FIG. 3 , there are at least two exhaust holes 121 b , and the exhaust holes 121 b are arranged in pairs along the radial direction of the shaft assembly 12 .

[0091] In the disclosed embodiment, the number of exhaust holes 121b is even. After one of the exhaust holes 121b is rotated 180° in the circumferential direction, it can coincide with the initial position of the other exhaust hole 121b, which is beneficial for the shaft body 121 to maintain dynamic balance during high-speed rotation.

[0092] In one embodiment, referring to FIG. 1 to FIG. 3 , the exhaust hole 121 b is tilted along the radial direction of the shaft assembly 12 , and the tilt direction of the exhaust hole 121 b is coaxial with the rotation direction of the shaft assembly 12 .

[0093] In the disclosed embodiment, the axial direction of the exhaust hole 121b does not coincide with the radial direction of the shaft assembly 12, but is inclined at a certain angle. The inclination direction is the same as the rotation direction of the shaft assembly 12. This makes it difficult for airflow to enter the interior of the shaft assembly 12 when the shaft assembly 12 rotates at high speed, thereby reducing the impact of the rotating airflow on the windage loss of the shaft assembly 12. As shown in Figure 3, the rotation direction indicated by the reference numeral A is the rotation direction of the shaft assembly 12.

[0094] In one embodiment, referring to Figures 1 and 4 , the working component 10 further includes a locking member 15 and a displacement sensor mounted on the locking member 15. The locking member 15 is disposed at the end of the shaft assembly 12 away from the permanent magnet assembly 11. The displacement sensor is used to monitor the axial and radial motion trajectory of the motor rotor system.

[0095] In the disclosed embodiment, the locking members 15 are provided at both ends of the rotor assembly 1 in the axial direction, which can lock the various working components 10 on the rotor assembly 1 to prevent the working components 10 from axially moving when the rotor assembly 1 rotates at high speed.

[0096] Exemplarily, the locking member 15 may be a nut.

[0097] In one embodiment, referring to FIG. 1 and FIG. 4 , a positioning stop may be further provided on the outer side of one end of the shaft assembly 12 that engages with the locking member 15 .

[0098] In the disclosed embodiment, while locking member 15 secures working component 10 to rotor assembly 1, the precise positioning of locking member 15 enables the displacement sensor to accurately monitor the axial and radial motion trajectory of the motor rotor system, thereby visually monitoring the operating status of the motor rotor system. Based on this operating status, the cause of vibration in the motor rotor system can be further analyzed, precursors to faults can be identified, and timely measures can be taken to prevent the fault from worsening.

[0099] The material of the locking member 15 is not limited, and can be, for example, iron, cobalt or nickel. For example, the locking member 15 is made of GH4169 high-temperature nickel-based alloy.

[0100] In another aspect, an embodiment of the present disclosure provides a permanent magnet motor, comprising the motor rotor system and the stator core 3 described in any of the aforementioned embodiments.

[0101] In one embodiment, referring to FIG. 1 , the axial length of the permanent magnet assembly 11 is greater than the axial length of the stator core 3 .

[0102] In the embodiment of the present disclosure, since the axial length of the permanent magnet assembly 11 is greater than the axial length of the stator core 3, when the permanent magnet assembly 11 is assembled, the axial length of the stator core 3 will not exceed the axial length range of the permanent magnet assembly 11 due to assembly errors or processing size errors. Subsequently, when the permanent magnet assembly 11 rotates at high speed, no additional axial force will be generated to cause the permanent magnet assembly 11 to move axially, and the permanent magnet assembly 11 has a certain fault tolerance capability.

[0103] In one embodiment, referring to FIG. 1 , the permanent magnet motor may be used in an air compressor, and the working component 10 further includes a low-pressure side impeller 161 , a high-pressure side impeller 162 , and a thrust plate 17 .

[0104] In the disclosed embodiment, the low-pressure side impeller 161 and the high-pressure side impeller 162 are respectively arranged at both ends of the shaft assembly 12 and are locked by the locking member 15, and can rotate together with the shaft assembly 12; the thrust plate 17 is arranged between the support device 2 and the high-pressure side impeller 162, and can rotate together with the shaft assembly 12. When the low-pressure side impeller 161 and the high-pressure side impeller 162 rotate together with the shaft assembly 12, the air is compressed once by the low-pressure side impeller 161 and then enters the high-pressure side impeller 162 for secondary compression. Since the axial thrusts exerted on the impellers on both sides are inconsistent, the rotor assembly 1 tends to move to one side. At this time, the thrust plate 17 plays an axial bearing role to prevent the rotor assembly 1 from deviating to one side.

[0105] The material of the low-pressure side impeller 161 and the high-pressure side impeller 162 is not limited, and can be, for example, iron, cobalt, or nickel. For example, the low-pressure side impeller 161 and the high-pressure side impeller 162 are made of 2A70 aviation aluminum alloy.

[0106] The material of the thrust plate 17 is not limited, and can be, for example, iron, cobalt or nickel. For example, the thrust plate 17 is made of GH4169 high temperature nickel-based alloy.

[0107] In one embodiment, referring to FIG. 1 and FIG. 2 , the shaft assembly 12 has shaft shoulders at the low-pressure side impeller 161 , the high-pressure side impeller 162 , and the thrust plate 17 .

[0108] In the embodiment of the present disclosure, the low-pressure side impeller 161, the high-pressure side impeller 162 and the thrust plate 17 all have shaft shoulders on the shaft assembly 12 to locate the position of each component, which is beneficial to improving the positioning accuracy of the low-pressure side impeller 161, the high-pressure side impeller 162 and the thrust plate 17.

[0109] In one embodiment, the end surface of the low-pressure side impeller 161, the end surface of the high-pressure side impeller 162 and the end surface of the thrust plate 17 are all laser-marked (not shown).

[0110] In the embodiment of the present disclosure, laser markings are performed on the end faces of the low-pressure side impeller 161, the high-pressure side impeller 162 and the thrust plate 17 to locate the installation angles of the low-pressure side impeller 161, the high-pressure side impeller 162 and the thrust plate 17 after the rotor assembly 1 is assembled and balanced. This allows for rapid repeating of radial positioning when the rotor assembly 1 is disassembled for maintenance or other reasons and then reinstalled, thereby ensuring consistency before and after reinstallation of the rotor assembly 1 and avoiding changes in the imbalance amount when the rotor assembly 1 is reinstalled, which may affect the stability of the rotor assembly 1.

[0111] In one embodiment, referring to FIG. 1 and FIG. 2 , outer hexagonal square heads 1211 may be further provided at both ends of the shaft body 121 along the axial direction to facilitate installation of the locking member 15 .

[0112] In the disclosed embodiment, by providing external hexagonal square heads 1211 on both axial sides of the shaft body 121, when the locking member 15 is installed at one axial end of the shaft body 12, the external hexagonal square head 1211 at the other end can be used to secure the rotor assembly 1, ensuring that the locking member 15 achieves a predetermined locking force. Furthermore, since a puller is not required to install the locking member 15, the shaft body 121 can be thinned at both axial ends, which not only reduces the weight of the rotor assembly 1 but also facilitates flexible impeller design.

[0113] For example, referring to Figures 1 and 2 , when installing the locking member 15 on the left side of the shaft body 121, a wrench is used to tighten the outer hexagonal square head 1211 on the right side of the shaft body 121. This prevents the rotor assembly 1 from rotating until the locking member 15 reaches a predetermined locking force. Similarly, when installing the locking member 15 on the right side of the shaft body 121, a wrench is used to tighten the outer hexagonal square head 1211 on the left side of the shaft body 121. This prevents the rotor assembly 1 from rotating until the locking member 15 reaches a predetermined locking force.

[0114] Referring to FIG5 , a third aspect of the present disclosure provides a method for manufacturing a motor rotor system. The rotor assembly 1 includes a working component 10 and a permanent magnet assembly 11 . The working component 10 includes a sheath 13 and a shaft assembly 12 . The manufacturing method includes:

[0115] Step S1, using the outer circumference of the permanent magnet assembly 11 as a radial positioning reference, and sleeve the sheath 13 on the permanent magnet assembly 11;

[0116] Step S2 , using the sheath 13 as an axial positioning reference, determining the position of the shaft assembly 12 relative to the sheath 13 along the axial direction of the sheath 13 .

[0117] The manufacturing method of the motor rotor system provided in the embodiment of the present disclosure is suitable for high-speed permanent magnet motors. The outer peripheral surface of the permanent magnet component 11 is used as the radial positioning reference, and the sleeve 13 is used as the axial positioning reference to assemble and fine-process the rotor assembly 1 to ensure the dimensional tolerance and positional tolerance of the rotor assembly 1. The distance between the center of gravity 1a of the rotor assembly 1 and the first support rotation center 1b and the second support rotation center 1c are equal, thereby improving the stability of the rotor assembly 1 during high-speed rotation.

[0118] The control method of the embodiment of the present disclosure is described in detail below with reference to specific embodiments.

[0119] Illustratively, before step S1 , the manufacturing method includes: polishing the outer peripheral surface of the permanent magnet assembly 11 to improve the processing accuracy of the permanent magnet assembly 11 .

[0120] Illustratively, in step S1 , the permanent magnet assembly 11 is interference fitted into the sheath 13 with the outer circumferential surface of the permanent magnet assembly 11 as a reference, so that no gap exists between the mating surfaces of the permanent magnet assembly 11 and the sheath 13 .

[0121] For example, the interference fit between the permanent magnet assembly 11 and the sheath 13 is 0.01 to 0.014 mm.

[0122] Illustratively, before step S2 , the manufacturing method includes: further grinding the shaft assembly to improve the machining accuracy of the shaft assembly.

[0123] Exemplarily, in step S2, the relative position of the shaft assembly 12 and the sleeve 13 in the axial direction is determined with the sleeve 13 as the axial positioning reference to ensure the assembly accuracy of the shaft assembly 12 and the sleeve 13 so that the shaft assembly 12 and the sleeve 13 are as coaxial as possible.

[0124] Illustratively, after step S2 , the shaft assembly 12 and the sheath 13 are laser welded to form an integral whole.

[0125] Exemplarily, the laser welding depth of the shaft assembly 12 and the sheath 13 is 3 mm.

[0126] In one embodiment, the permanent magnet assembly 11 specifically includes:

[0127] In step S11 , a plurality of disc-shaped permanent magnets 111 are bonded together to form the cylindrical permanent magnet assembly 11 .

[0128] Specifically, the permanent magnet assembly 11 is composed of multiple disc-shaped permanent magnets 111 with consistent magnetic field orientations bonded together, which is firm and reliable.

[0129] The foregoing description is merely a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present disclosure shall be included within the scope of protection of the present disclosure.

Claims

1. A motor rotor system, comprising: A support device having a first support rotation center and a second support rotation center arranged at intervals; A rotor assembly rotatably connected to the support device at the first support rotation center and the second support rotation center respectively. The rotor assembly rotates around the connection line between the first support rotation center and the second support rotation center. The distance between the first support rotation center and the center of gravity of the rotor assembly is a first distance, and the distance between the second support rotation center and the center of gravity of the rotor assembly is a second distance, and the first distance is equal to the second distance.

2. The motor rotor system according to claim 1, wherein, The midpoint of the connection line between the first support rotation center and the second support rotation center coincides with the center of gravity of the rotor assembly.

3. The motor rotor system according to claim 1 or 2, wherein, The support device includes two support members arranged at intervals. The first support rotation center is formed on one of the support members, and the second support rotation center is formed on the other support member.

4. The motor rotor system according to any one of claims 1 to 3, wherein, The rotor assembly includes: A working component having a receiving cavity; A permanent magnet assembly installed in the receiving cavity, and the permanent magnet assembly is a solid structure.

5. The motor rotor system according to claim 4, wherein, The permanent magnet assembly includes a plurality of stacked permanent magnets and an insulating layer disposed between adjacent two permanent magnets, and the permanent magnets are configured as disk-shaped.

6. The motor rotor system according to claim 4 or 5, wherein, The working component includes: A sheath; A shaft assembly. The sheath is respectively provided with the shaft assembly at both axial ends, and the sheath and the shaft assembly enclose the receiving cavity.

7. The motor rotor system according to claim 6, wherein, The sheath is welded to the shaft assembly; and / or, the permanent magnet assembly is located inside the sheath, and the sheath and the permanent magnet assembly are in interference fit.

8. The motor rotor system according to claim 6 or 7, wherein, The shaft assembly has a weight reduction hole formed at one end of the shaft assembly close to the permanent magnet assembly.

9. The motor rotor system according to claim 8, wherein, The shaft assembly includes: A shaft body, and the weight reduction hole is formed inside the shaft body; A cover disposed between the shaft body and the permanent magnet assembly to close the weight reduction hole.

10. The motor rotor system according to claim 8 or 9, wherein, The shaft assembly also has an exhaust hole communicating with the outside to communicate the weight reduction hole with the outside.

11. The motor rotor system according to claim 10, wherein, There are at least two exhaust holes, and the exhaust holes are arranged in pairs along the radial direction of the shaft assembly; and / or, The exhaust holes are arranged obliquely along the radial direction of the shaft assembly, and the inclination direction of the exhaust holes is the same as the rotation direction of the shaft assembly.

12. The motor rotor system according to any one of claims 6 to 11, wherein, The working component further includes a locking member and a displacement sensor installed on the locking member. The locking member is disposed at one end of the shaft assembly away from the permanent magnet assembly, and the displacement sensor is used to monitor the movement trajectories of the motor rotor system along the axial and radial directions.

13. A permanent magnet motor, comprising: The motor rotor system according to any one of claims 1 to 12; A stator core.

14. The permanent magnet motor according to claim 13, wherein, The length of the permanent magnet assembly along the axial direction is greater than the length of the stator core along the axial direction.

15. A manufacturing method of a motor rotor system. The rotor assembly includes a working component and a permanent magnet assembly. The working component includes a sheath and a shaft assembly. The manufacturing method includes: Taking the outer peripheral surface of the permanent magnet assembly as the radial positioning reference, sleeving the sheath on the permanent magnet assembly; Taking the sheath as the axial positioning reference, determining the position of the shaft assembly along the axial direction of the sheath relative to the sheath.

16. The manufacturing method according to claim 15, wherein, The permanent magnet assembly specifically includes: A plurality of disk-shaped permanent magnets are bonded to form the permanent magnet assembly in a cylindrical shape.

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