CN113691040A

CN113691040A - Motor rotor and manufacturing method

Info

Publication number: CN113691040A
Application number: CN202110762140.2A
Authority: CN
Inventors: 尚前博; 侯晓军; 庞聪; 武媛; 耿涛; 齐影
Original assignee: CRRC Yongji Electric Co Ltd
Current assignee: CRRC Yongji Electric Co Ltd
Priority date: 2021-07-06
Filing date: 2021-07-06
Publication date: 2021-11-23
Anticipated expiration: 2041-07-06
Also published as: CN113691040B

Abstract

The invention relates to the field of electric appliances, and an embodiment of the invention provides a motor rotor, at least part of which is obtained by additive manufacturing, the motor rotor comprises: squirrel cage subassembly and motor shaft, wherein, motor shaft includes: the installation part extends along a first direction, a cavity is arranged in the installation part, and the squirrel cage assembly is sleeved on at least part of the installation part; the transmission part is arranged at the end part of the mounting part and extends along the first direction; in a cross section perpendicular to the first direction, the outer edge size of the mounting part is larger than that of the transmission part, and the ratio of the outer edge size of the mounting part to that of the transmission part is larger than a preset value. Such a motor rotor has a low weight.

Description

Motor rotor and manufacturing method

Technical Field

The invention relates to the field of electric appliances, in particular to a motor rotor and a manufacturing method thereof.

Background

The motor rotor is a rotating part in the motor, the squirrel-cage motor rotor generally comprises a motor rotating shaft and a squirrel-cage assembly, and the squirrel-cage assembly is sleeved outside the motor rotating shaft. The motor rotating shaft has a large weight, which results in a large overall weight of the motor rotor.

Disclosure of Invention

In view of this, the present invention provides a motor rotor, which is used to solve the technical problem of how to reduce the weight of the motor rotor, thereby reducing the overall weight of the motor.

An embodiment of the present invention provides an electric motor rotor, at least a part of which is obtained by additive manufacturing, the electric motor rotor including:

the squirrel cage component and the motor rotating shaft are arranged on the motor; wherein, the motor shaft includes: the installation part extends along a first direction, a cavity is arranged in the installation part, and the squirrel cage assembly is sleeved on at least part of the installation part; the transmission part is arranged at the end part of the mounting part and extends along the first direction; in a cross section perpendicular to the first direction, the outer edge size of the mounting part is larger than that of the transmission part, and the ratio of the outer edge size of the mounting part to that of the transmission part is larger than a preset value.

Further, the transmission part is internally provided with the cavity.

Further, at least one of the cavity in the mounting portion and the cavity in the transmission portion includes a closed cavity.

Further, the mounting portion includes: the squirrel cage assembly is sleeved on the sleeving part, and the transmission part is arranged at the end part of the sleeving part; the positioning part extends out of the circumferential outer surface of the sleeving part along a second direction and is abutted with one end of the squirrel cage assembly; wherein the second direction is substantially perpendicular to the first direction.

Further, the distance that the locating part extends out of the circumferential outer surface of the sleeving part is larger than a preset threshold value.

Further, the outer surface of the sleeving part is provided with a heat dissipation air duct, and the length direction of the heat dissipation air duct is basically parallel to the first direction.

Further, the squirrel cage assembly includes: the rotor core extends along the first direction and is sleeved on at least part of the mounting part; the guide bars are arranged at intervals along the circumferential direction of the rotor core and penetrate through the rotor core; and the two end rings are respectively arranged on two sides of the rotor core and fixedly connected with the guide bars.

Furthermore, the end face of the conducting bar, which extends out of the rotor core, is fixedly connected with the end ring, and the distance between the end ring and the end face of the rotor core is smaller than a preset value.

Further, the preset value is 5 mm.

Further, the end rings are provided with mounting grooves for accommodating the connecting parts of the guide bars and the end rings.

The embodiment of the invention also provides a manufacturing method of the motor rotor, which is characterized in that the motor rotor comprises the following components: an end ring, a motor shaft; the manufacturing method comprises the following steps: the end ring and the motor shaft are obtained by additive manufacturing.

An embodiment of the present invention provides a motor rotor, including: squirrel-cage subassembly and motor shaft, motor shaft include along the transmission portion and the installation department of first direction extension, and is provided with the cavity in the installation department, and rotor core sleeve locates at least partial installation department, wherein, in the cross-section of the first direction of perpendicular to, the outer fringe size of installation department is greater than the outer fringe size of transmission portion, and the ratio of the outer fringe size of installation department and the outer fringe size of transmission portion is greater than the default, promptly, the outer fringe size of installation department is greater than the outer fringe size of transmission portion. The outer edge size of the installation part is set to be larger, the installation part is sleeved with the rotor core, meanwhile, the cavity is arranged in the installation part, the inner structure of one part of the rotor core can be integrated in the installation part of the motor rotating shaft, the solid structure in the rotor core is replaced by the structure with the cavity, the weight of the motor rotor is reduced, and the whole weight of a motor adopting the motor rotor is reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a rotor of an electric machine according to an embodiment of the present invention;

fig. 2 is a cross-sectional view of a rotating shaft of an electric machine in a rotor of the electric machine according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a motor rotating shaft in a motor rotor according to an embodiment of the present invention;

FIG. 4 is an exploded view from a first perspective of a squirrel cage assembly in a motor rotor according to embodiments of the present invention;

FIG. 5 is an exploded view from a second perspective of a squirrel cage assembly in a motor rotor according to embodiments of the present invention;

FIG. 6 is a schematic view of an assembly of a conducting bar and an end ring in the squirrel cage assembly provided by an embodiment of the present invention;

FIG. 7 is a schematic view of the assembly of another conducting bar and end ring in the squirrel cage assembly provided by the embodiments of the invention;

FIG. 8 is an exploded view of a conducting bar and rotor core in a squirrel cage assembly according to an embodiment of the present invention;

FIG. 9 is a schematic flow chart illustrating a method of manufacturing a rotor for an electric machine according to an embodiment of the present invention;

FIG. 10 is a schematic flow chart of a method of manufacturing a squirrel cage assembly in a rotor of an electric motor according to an embodiment of the present invention;

FIG. 11 is a schematic flow chart of another method of manufacturing a squirrel cage assembly in a rotor of an electric motor according to embodiments of the present invention;

FIG. 12 is a schematic flow chart of another method of manufacturing a squirrel cage assembly in a rotor of an electric motor according to embodiments of the present invention;

fig. 13 is a schematic flow chart of a method for manufacturing a rotating shaft of an electric machine in an electric machine rotor according to an embodiment of the present invention.

Description of reference numerals:

1. a squirrel cage assembly; 10. a rotor core; 2. a motor shaft; 21. an installation part; 211. a housing portion; 212. a positioning part; 213. a heat dissipation air duct; 22. a transmission section; 23. a cavity; 24. reinforcing ribs; 25. a bearing seal portion; 11. a first end face; 12. a second end face; 13. positioning a groove; 20. conducting bars; 201. a first limit structure; 30. an end ring; 301. a first end ring; 302. a second end ring; 31. mounting grooves; 311. a support groove; 312. a limiting part.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The individual features described in the embodiments can be combined in any suitable manner without departing from the scope, for example different embodiments and aspects can be formed by combining different features. In order to avoid unnecessary repetition, various possible combinations of the specific features of the invention will not be described further.

In a particular embodiment of the invention, the motor rotor may be adapted for any type of motor, for example, the motor rotor may be adapted for a synchronous motor, for an asynchronous motor, or for a stepper motor. The structure of the motor rotor is exemplified by taking the motor rotor as an example suitable for a squirrel-cage asynchronous motor, and the type of the motor does not affect the structure of the motor rotor.

In some embodiments, as shown in fig. 1, the electric machine rotor comprises: the squirrel-cage assembly 1 is connected with the motor rotating shaft 2, and the motor rotating shaft 2 is connected with the squirrel-cage assembly 1 to support the squirrel-cage assembly 1. Specifically, electric motor rotor 1 still includes the casing, and this casing surrounds to form and holds the chamber, and squirrel cage subassembly 1 and motor shaft 2 partly are located this and hold the intracavity, and motor shaft 2's both ends are rotatably connected with this casing, and motor shaft 2's outside is located to squirrel cage subassembly 1 cover, and simultaneously, motor shaft 2 still is connected with electric motor rotor's rotating part, and this casing is stretched out to some motor shaft 2 for be connected with other devices that need the drive, with output electric motor rotor's kinetic energy.

The motor shaft 2 includes a mounting portion 21 and a transmission portion 22. The mounting portion 21 extends in a first direction (the first direction is indicated by an arrow in fig. 1), and a cavity 23 is provided inside the mounting portion 21. The squirrel cage component 1 is sleeved on at least part of the mounting part 21; specifically, the cage assembly 1 is provided with mounting through holes, and at least part of the mounting portion 21 is located in the mounting through holes. The transmission part 22 is disposed at an end of the mounting part 21 and extends in the first direction, and the transmission part 22 is used for extending out of the housing of the motor rotor and connecting with other devices to be driven so as to drive other devices.

In a cross section perpendicular to the first direction, the outer edge dimension of the mounting portion 21 is greater than the outer edge dimension of the transmission portion 22, and a ratio of the outer edge dimension of the mounting portion 21 to the outer edge dimension of the transmission portion 22 is greater than a preset value, that is, in the cross section perpendicular to the first direction, the outer edge dimension of the mounting portion 21 is much greater than the outer edge dimension of the transmission portion 22, for example, the preset value is 2, and it can be understood that the outer edge dimension of the mounting portion 21 is at least 2 times the outer edge dimension of the transmission portion 22. For convenience of description, the design concept and the advantageous effects of the motor rotating shaft 2 will be exemplarily described below by taking the mounting portion 21 and the transmission portion 22 as circular shafts, and the outer edge dimension of the mounting portion 21 and the outer edge dimension of the transmission portion 22 in a cross section perpendicular to the first direction are referred to as the shaft diameter of the mounting portion 21 and the shaft diameter of the transmission portion 22, respectively.

The following explains the design concept of the motor shaft 2 according to the present embodiment. The motor rotating shaft 2 provided by the present embodiment is integrally manufactured by additive manufacturing, rather than by cutting or welding, and for the structure of the motor rotating shaft 2 provided by the present embodiment, in which the shaft diameter of one portion is much larger than that of the other portion, the method of cutting or welding is not suitable, and is very economical. Specifically, the motor rotating shaft 2 is obtained by cutting, a blank with a shaft diameter not less than the shaft diameter of the mounting portion 21 needs to be manufactured, the shaft diameter of the portion of the blank corresponding to the transmission portion 22 is cut by cutting to be slightly greater than or equal to the shaft diameter of the mounting portion 21 from the shaft diameter not less than the shaft diameter of the mounting portion 21, a large amount of metal materials are consumed in the cutting process, meanwhile, due to the fact that the cutting amount is large, in order to prevent a cutter from being overheated or the cutter from being broken in the cutting process, the transmission portion 22 needs to be obtained by cutting for multiple times, and the machining process is complex and time and labor consuming. Processing installation department 21 and transmission portion 22 respectively to install installation department 21 and transmission portion 22 as an organic whole through the welding, although can reduce cutting process's cutting output, can leave the welding seam in the welding department, also have simultaneously because the deformation that the welding arouses or the quality risk increase problem that stress concentration leads to, motor shaft 2's wholeness is not good, at the rotatory in-process of motor shaft 2, the stress that motor shaft 2 received can concentrate in welding seam department, lead to motor shaft 2's life to reduce. The possibility that the above-mentioned problem appears can be reduced through the vibration material disk, and is concrete, obtains holistic motor shaft structure according to the actual size needs of each part of motor shaft 2, can reduce the cutting volume of material, and simultaneously, the structural integrity of the motor shaft 2 who obtains is high, can alleviate the phenomenon of stress concentration when receiving stress, prolongs motor shaft 2's life. In summary, under the premise that the motor rotating shaft is manufactured by cutting or welding, and the motor rotating shaft 2 can be manufactured by additive manufacturing, a person skilled in the art will not design the motor rotating shaft as the structure of the motor rotating shaft 2 provided in the present embodiment. The specific method for obtaining the motor shaft 2 through additive manufacturing is described in other embodiments, and therefore will not be described herein.

The following describes advantageous effects of the motor rotor to which the motor shaft 2 is applied. The shaft diameter of installation department 21 is great, and the inside of installation department 21 is provided with the cavity, locates the outside of the installation department 21 that has great shaft diameter with squirrel cage subassembly 1 cover, is equivalent to replace the entity part of squirrel cage subassembly 1 for having the structure of cavity, so, has reduced the weight of squirrel cage subassembly to reduce electric motor rotor's weight, and then reduced the weight of the motor that has used this electric motor rotor. Specifically, the squirrel cage assembly 1 is provided with a mounting through hole, and at least part of the mounting part 21 is positioned in the mounting through hole, so that the squirrel cage assembly 1 is sleeved on the mounting part 21. The shaft diameter of the mounting part 21 is set to be larger, the hole diameter of the mounting through hole of the squirrel cage assembly 1 can be increased, and meanwhile, the cavity 23 is formed in the mounting part 21, so that part of the solid structure in the squirrel cage assembly 1 is integrated in the mounting part 21 of the motor rotating shaft 2, and the solid structure is replaced by a structure with the cavity, so that the weight of the motor rotor is reduced, and the whole weight of a motor adopting the motor rotor is reduced. It should be noted that only a part of the structure near the outer surface of the squirrel cage assembly 1 participates in the electromagnetic induction and is used for enhancing the strength of the electromagnetic induction, while the internal structure of the squirrel cage assembly 1 does not participate in the electromagnetic induction, the internal structure of the squirrel cage assembly 1 is integrated on the mounting part 21 of the motor rotating shaft 2, and the material of the part is replaced by a structure with a cavity from a solid structure, so that the mass of the motor rotor can be reduced on the premise of not affecting the strength of the electromagnetic induction of the motor rotor.

An embodiment of the present invention provides a motor rotor, including: squirrel-cage subassembly and the motor shaft who is connected with the squirrel-cage subassembly, motor shaft includes transmission portion and the installation department that extends along the first direction, and is provided with the cavity in the installation department, at least partial installation department is located to the rotor heart cover, wherein, in the cross-section of the first direction of perpendicular to, the outer fringe size of installation department is greater than the outer fringe size of transmission portion, and the ratio between the outer fringe size of installation department and the outer fringe size of transmission portion is greater than the default, promptly, the outer fringe size of installation department is greater than the outer fringe size of transmission portion greatly. The outer edge size of the installation part is set to be larger, the rotor core is sleeved on the installation part, meanwhile, the cavity is arranged in the installation part, the internal structure of part of the squirrel cage assembly can be integrated in the installation part of the motor rotating shaft, the solid structure in the squirrel cage assembly is replaced by the structure with the cavity, the weight of the motor rotor is reduced, and the whole weight of a motor adopting the motor rotor is reduced.

In some embodiments, as shown in fig. 1, in a cross section perpendicular to the first direction, a ratio of an outer edge dimension of the mounting portion 21 to an outer edge dimension of the transmission portion 22 is greater than a preset value and the preset value is not less than 1.5, that is, in a cross section perpendicular to the first direction, an outer edge dimension of the mounting portion 21 is at least 1.5 times an outer edge dimension of the transmission portion 22, and exemplarily, in a cross section perpendicular to the first direction, an outer edge dimension of the transmission portion 22 is 100 mm, and then an outer edge dimension of the mounting portion 21 is not less than 150 mm.

In some embodiments, as shown in fig. 2, a cavity 23 is provided in the mounting portion 21, and by providing the cavity 23 in the transmission portion 22, the weight of the motor rotating shaft 2 is further reduced, and thus the weight of the motor rotor 1 is further reduced. Optionally, the volume of the cavity 23 disposed in the transmission portion 22 is smaller than the volume of the cavity 23 disposed in the mounting portion 21, that is, so as to fully utilize the internal space of the mounting portion 21, and a cavity with a larger volume is disposed in the mounting portion 21 with a larger volume, thereby further reducing the overall weight of the motor rotor 1. It should be noted that the cavities 23 in the mounting portion 21 and the transmission portion 22 may be arranged in any form, for example, the cavities 23 in the mounting portion 21 and the transmission portion 22 may be arranged at intervals along the first direction, for example, the cavities 23 in the mounting portion 21 and the transmission portion 22 may also extend along the first direction and communicate with each other. It should be noted that the size of the cavity in the transmission part 22 also needs to be determined according to the strength of the transmission part 22, so that the transmission part 22 does not break or deform while transmitting torque.

Optionally, a cavity 23 is formed at an end of the transmission portion 22, and after the integrally formed motor shaft 2 is obtained through additive manufacturing, the motor shaft 2 may be fixed on a processing machine through the cavity 23 formed at the end of the transmission portion 22, and the motor shaft 2 may be further processed. For example, after the integrally molded motor shaft 2 is obtained through additive manufacturing, the outer surface of the mounting portion 21 needs to be further processed through grinding, so that the dimensional accuracy and the surface roughness of the outer surface of the mounting portion 21 meet design requirements, one end of the motor shaft 2 can be clamped by a clamping jaw of a grinding machine, and a mandril of the grinding machine is pushed against the cavity 23 of the end face of the transmission portion 22, so that the motor shaft 2 is fixed on the grinding machine.

In some embodiments, as shown in fig. 2, the cavities 23 in the mounting portion 21 and the transmission portion 22 both extend in a first direction (the first direction is indicated by an arrow in fig. 2), i.e. the cavities 23 extend in the same direction as the mounting portion 21 and the transmission portion 22. The extending direction of the cavity 23 is set to be the same as the length direction of the mounting part 21 and the transmission part 22, the structure of the motor rotating shaft 2 is simplified, the manufacturing difficulty of the motor rotating shaft 2 is reduced, meanwhile, the weight of each part of the mounting part 21 in the first direction is the same, the weight of each part of the transmission part 22 in the first part is the same, the dynamic unbalance of the motor rotating shaft 2 in rotation is reduced, the vibration and the noise of the motor rotor 1 in the rotation process are reduced, and the service life of the motor rotating shaft 2 is prolonged. Optionally, as shown in fig. 2, a mass center axis of the cavity 23 in the mounting portion 21 coincides with a mass center axis of the mounting portion 21, and a mass center axis of the cavity 23 in the transmission portion 22 coincides with a mass center axis of the transmission portion 22, so as to further reduce the dynamic unbalance degree of the motor rotating shaft 2 in the rotating process, thereby reducing vibration and noise generated by the motor rotor in the rotating process, and further prolonging the service life of the motor rotating shaft 2.

In some embodiments, as shown in fig. 2, in a cross section perpendicular to the first direction, an outer edge dimension of the cavity 23 in the mounting portion 21 is larger than an outer edge dimension of the cavity in the transmission portion 22, that is, the cross section of the cavity in the mounting portion 21 is set to be larger than the cross section of the cavity 23 in the transmission portion 22 on the premise that the cavity 23 extends in the first direction (the first direction is indicated by an arrow in fig. 2), so that the internal space of the mounting portion 21 having a larger size is fully utilized on the premise that the dynamic unbalance degree of the motor rotating shaft 2 is reduced, thereby further reducing the weight of the motor rotating shaft 2 and further reducing the weight of the motor rotor.

In some embodiments, as shown in fig. 2, at least one of the cavities 23 in the mounting portion 21 and the transmission portion 22 is a closed cavity, wherein the closed cavity is completely located inside the mounting portion 21 or the transmission portion 22 and is not communicated with the external space of the motor rotating shaft 2, so that while the cavity is provided in the motor rotating shaft 2, the possibility that dust or liquid in the external space of the motor rotating shaft 2 enters the closed cavity is reduced, the possibility that the inside of the motor rotating shaft 2 is corroded is reduced, and the service life of the motor rotating shaft 2 is prolonged. Optionally, the cavities 23 in the mounting portion 21 and the transmission portion 22 are closed cavities. It should be noted that, through cutting or casting process, it is impossible to provide a closed cavity in the mounting portion 21 and the transmission portion 22 of the integrally formed motor shaft 2, specifically, through cutting, a cavity communicated with the external space of the motor shaft 2 needs to be obtained in the motor shaft 2 through cutting, and then through means such as welding or splicing, an opening of the cavity is closed by using a closing element, such processing steps are complicated, and the integrally formed motor shaft 2 cannot be realized, the integrity of the motor shaft 2 is not good, stress concentration is easily formed at splicing positions such as a welding seam, and further, the service life of the motor shaft 2 is shortened, and obtaining the motor shaft 2 with a closed cavity through casting may cause that a core cannot be taken out from the motor shaft 2 after the motor shaft 2 is cast. Can overcome above-mentioned problem through vibration material disk, with motor shaft 2 integrated into one piece, when improving motor shaft 2's wholeness, can also directly process and obtain motor shaft 2 that has closed cavity, to sum up, technical personnel in the art are forming through cutting process or casting, and do not realize can not setting up closed cavity in motor shaft 2's installation department 21 and transmission 22 under the prerequisite through vibration material disk integrated into one piece motor shaft 2.

Optionally, with reference to fig. 1 and 2, a wall surface of the mounting portion 21 and/or the transmission portion 22 adjacent to the cavity 23 is provided with a reinforcing rib 24, and the reinforcing rib 24 extends from the wall surface to the inside of the cavity 23, so that on the premise of not affecting the shape of the outer surface of the motor rotating shaft 2, the structural strength of the motor rotating shaft 2 is improved, and the service life of the motor rotating shaft 2 is further prolonged. Optionally, the reinforcing rib 24 extends along the first direction, and the plurality of reinforcing ribs 24 are arranged in the cavity 23 around the first direction at intervals, so that the strength of the motor rotating shaft 2 is further increased, and the service life of the motor rotating shaft 2 is prolonged. It should be noted that the skilled person would not think of providing the reinforcing ribs 24 in the closed cavity, without the skilled person thinking of making the motor shaft 2 with the closed cavity integrally by additive manufacturing.

In some embodiments, as shown in fig. 3, the mounting portion 21 includes: a sleeve portion 211 and a positioning portion 212. The squirrel cage assembly 1 shown in fig. 1 is sleeved on the sleeved portion 211, and the transmission portion 22 is disposed at an end of the sleeved portion 211, alternatively, the transmission portion 22 may be disposed at one end of the sleeved portion 211, or disposed at two ends of the sleeved portion 211. The positioning portion 212 extends from the circumferential outer surface of the sleeving portion 211 to a second direction (the second direction is shown by a dotted arrow in fig. 3), wherein the axial outer surface of the positioning portion 212 may be the outer surface of the non-end portion of the positioning portion 212, and after the squirrel cage assembly 1 is sleeved on the sleeving portion 211, the positioning portion 212 can abut against one end surface of the squirrel cage assembly 1 in a first direction (the first direction is shown by a solid arrow in fig. 3), so that the movement of the squirrel cage assembly 1 relative to the sleeving portion 211 in the first direction is limited. The second direction is substantially perpendicular to the first direction, that is, the positioning portion 212 extends along a direction substantially perpendicular to the outer surface of the sleeving portion 211, so that the size of the positioning portion 212 perpendicular to the direction of the sleeving portion 211 is fully utilized, the contact area between the positioning portion 212 and the squirrel cage assembly 1 is increased, and the movement of the squirrel cage assembly 1 relative to the sleeving portion 211 along the first direction is more reliably limited, and the second direction is substantially perpendicular to the first direction, it can be understood that an included angle is allowed to exist between the first direction and the second direction due to manufacturing errors, and the difference between the included angle between the first direction and the second direction and 90 degrees is smaller than a preset angle, for example, the preset angle is 5 degrees, and then the included angle between the first direction and the second direction is 85 degrees to 95 degrees. It should be noted that only one positioning portion 212 is provided on the circumferential outer surface of the sleeve portion 211, that is, the mounting portion 212 is only used for abutting against one side of the squirrel cage assembly 1 along the first direction, so as to limit the movement of the squirrel cage assembly 1 along one side of the first direction, and the assembly between the squirrel cage assembly 1 and the sleeve portion 211 is not affected.

In some embodiments, as shown in fig. 3, the protrusion distance of the positioning portion 212 from the circumferential outer surface of the sheathing portion 211 is greater than a preset threshold, that is, in a cross section perpendicular to the first direction, the outer edge dimension of the positioning portion 212 is much greater than the outer edge dimension of the sheathing portion 211, so as to increase the contact area between the end surface of the squirrel cage assembly 1 in the first direction and the positioning portion 212 in fig. 1, and further more reliably limit the movement of the squirrel cage assembly 1 relative to the motor rotating shaft 2 in the first direction, wherein the preset threshold may be, for example, half of the outer edge dimension of the squirrel cage assembly 1, so as to limit the movement of the squirrel cage assembly 1 in the first direction. It should be noted that, through cutting or welding, it is difficult to make the outer edge dimension of the positioning portion 212 much larger than the structure of the mounting portion 21 of the outer edge dimension of the sleeve portion 211, specifically, the mounting portion 21 of the motor shaft 2 is obtained through cutting, a blank having an axis diameter not smaller than the axis diameter of the positioning portion 212 needs to be manufactured, and the axis diameter of the portion of the blank corresponding to the sleeve portion 211 is cut to be slightly larger than or equal to the axis diameter of the sleeve portion 211 through cutting, so that a large amount of metal material is consumed in the cutting process. The portion 211 and the location portion 212 are established to the cover of processing installation department 21 respectively, then establish portion 211 and location portion 212 fixed connection with the cover through the welding, can produce the welding seam between the portion 211 and the location portion 212 are established to the cover, and the wholeness of installation department 21 is not good, and the stress that the installation department 21 of motor shaft 2 received can produce stress concentration in this welding seam department to shorten motor shaft 2's life. In summary, in the premise that the person skilled in the art manufactures the mounting portion 21 of the motor rotating shaft 2 by cutting or welding and does not think that the mounting portion 21 of the motor rotating shaft 2 can be obtained by additive manufacturing and integrated molding, the person skilled in the art will not design the mounting portion of the motor rotating shaft as the structure of the mounting portion 21 provided in the present embodiment.

In some embodiments, as shown in fig. 3, the heat dissipation air duct 213 is disposed on the outer surface of the sheathing part 211, the length direction of the heat dissipation air duct 213 is substantially parallel to the first direction (the first direction is shown by a solid arrow in fig. 3), after the squirrel cage assembly 1 in fig. 1 is sheathed on the mounting part 21, the air flow flowing in the heat dissipation air duct 213 can cool the squirrel cage assembly 1, thereby reducing the possibility that the squirrel cage assembly 1 is damaged due to overheating, prolonging the service life of the squirrel cage assembly 1, and meanwhile, compared with a heat dissipation scheme in which heat dissipation holes are disposed in a related motor rotor, the weight of the motor rotating shaft 2 is further reduced by disposing the heat dissipation air duct 213. The length direction of the heat dissipation air channel 213 may be the direction of the heat dissipation air channel 213 with the largest size, and the length direction of the heat dissipation air channel 213 is substantially parallel to the first direction, which may be understood as an included angle between the length direction of the heat dissipation air channel 213 and the first direction when manufacturing errors are allowed, and the included angle between the length direction of the heat dissipation air channel 213 and the first direction is smaller than a preset angle, and the preset angle may be 5 degrees.

Optionally, as shown in fig. 3, the heat dissipation air duct 213 penetrates through two end faces of the positioning portion 212 along the first direction, so as to extend the length of the heat dissipation air duct 213, further enhance the heat dissipation effect of the heat dissipation air duct on the squirrel cage assembly 1, improve the integration degree of the positioning portion 212 and the installation portion 21, improve the overall strength of the motor rotating shaft, and further extend the service life of the squirrel cage assembly 1. It should be noted that it is difficult to implement the structure in which the heat dissipation air duct 213 penetrates through the two end faces of the positioning portion along the first direction by cutting, specifically, the heat dissipation air duct 213 penetrates through the positioning portion 212 by cutting, and a cutter passing hole penetrating through the two end faces of the positioning portion 212 along the first direction needs to be formed in the positioning portion 212, so that a cutting tool passes through the positioning portion 212, which not only increases the manufacturing difficulty of the positioning portion 212, but also reduces the structural strength of the positioning portion 212, thereby reducing the reliability of the positioning portion 212 in limiting the movement of the squirrel cage assembly 1 relative to the housing portion 211 along the first direction. And process the locating part 212 and the cover portion 211 with heat dissipation wind channel 213 separately, and fix the locating part 212 in the peripheral surface of the cover portion 211 through welding, not only reduced the wholeness of the installation department 21, can produce stress concentration in the welding seam between the cover portion 211 and the locating part 212, reduce the life of the installation department 21, meanwhile, because the cover portion 211 is provided with the heat dissipation wind channel 213, the contact area between the cover portion 211 and the locating part 212 is less, the length of the cover portion 211 and the locating part 212 has been reduced, thereby reduce the fixing force between the cover portion 211 and the locating part 212, further reduce the overall structure intensity of the installation department 21. The problem of the above-mentioned machining by cutting or welding can be overcome by integrally forming the mounting portion 21 of the motor shaft 2 with the heat dissipation duct 213 penetrating the positioning portion 212 by additive manufacturing. In summary, under the premise that the person skilled in the art manufactures the mounting portion 21 of the motor rotating shaft 2 by cutting or welding, and does not think that the mounting portion 21 of the motor rotating shaft 2 can be obtained by additive manufacturing and integral molding, the person skilled in the art will not design the mounting portion of the motor rotating shaft as the structure of the mounting portion 21 provided in the present embodiment.

In some embodiments, the heat dissipating air channel 213 is formed by heat dissipating ribs disposed at intervals around the outer surface of the sleeving part 211, so that the heat dissipating ribs drive air to flow during the high-speed rotation process of the motor shaft 2, thereby cooling the squirrel cage assembly 1. In other embodiments, the fan blades are disposed inside the heat dissipation air channel 213, and during the rotation of the motor shaft 2, the fan blades rotate together and drive the air to move along the length direction of the heat dissipation air channel 213, so that the air is driven to move along the length direction of the heat dissipation air channel 213 and cool the rotor core in fig. 1 without an additional air driving device. Optionally, the fan blade is disposed at an opposite side of the positioning portion 212 to the side where the squirrel cage assembly 1 is disposed, so that the heat dissipation effect of the squirrel cage assembly 1 is further enhanced on the premise that the length of the portion of the heat dissipation air duct 213 contacting the squirrel cage assembly 1 is not required to be reduced.

In some embodiments, the motor shaft 2 further includes a balance block mounting structure for mounting a dynamic balance block at a corresponding position to reduce the dynamic unbalance of the motor shaft 2, thereby reducing the noise and vibration generated by the motor shaft 2 during the rotation process and prolonging the service life of the motor shaft 2. It should be noted that the balance weight mounting structure may be any structure capable of mounting a dynamic balance weight, for example, the balance weight mounting structure may be a threaded hole, and the dynamic balance weight is fixed to the threaded hole by a bolt, so that the dynamic balance weight is fixed to the motor shaft 2. Meanwhile, the balance weight mounting structure may be disposed at any position where the moment of inertia of the motor shaft 2 can be adjusted, for example, the dynamic balance mounting structure may be disposed on the surface of the positioning portion 212. Optionally, the motor shaft 2 is further provided with a transmission key, the transmission key is used for circumferentially fixing other accessories of the motor rotor which needs to be driven by the motor shaft 2 with the motor shaft 2, so that the motor shaft 2 can drive the accessories to rotate together, the transmission key is also used for circumferentially fixing the squirrel cage assembly 1 with the motor shaft 2, so that the rotor of the motor can drive the motor shaft 2 to rotate together, and the transmission key is integrally formed on the motor shaft 2 through material increase manufacturing, has high structural strength and can transmit larger torque.

In some embodiments, as shown in fig. 3, bearing sealing portions 25 are further disposed at both ends of the mounting portion 21, specifically, the transmission portion 22 is disposed at both ends of the mounting portion 21 along the first direction, the transmission portion 22 is rotatably connected with the housing of the motor, and a bearing is disposed between the transmission portion 22 and the housing of the motor 1. The bearings are lubricated by grease, and the two bearings are respectively abutted against the bearing sealing parts 25 at the two ends of the mounting part 21, so that the dissipation of the grease in the bearings is reduced, and the abrasion of the bearings is reduced. Optionally, the bearing sealing portion 25 is a labyrinth sealing ring, specifically, the end face of the labyrinth sealing ring for abutting against the bearing is provided with a plurality of annular sealing teeth arranged in sequence, a series of cut-off gaps and expansion cavities are formed between the teeth, and the sealed medium generates a throttling effect when passing through the gaps of the labyrinth to prevent the lubricating grease from dissipating. It should be noted that, the bearing sealing portion 25 is a portion integrated with the motor rotating shaft 2 in the process of manufacturing the motor rotating shaft 2 by additive manufacturing and integral molding, so that the integrity of the motor rotating shaft 2 is further increased, and the structural strength of the motor rotating shaft 2 is increased.

In some embodiments, in conjunction with fig. 4 and 5, the squirrel cage assembly 1 includes: rotor core 10, conducting bars 20 and end rings 30. The rotor core 10 extends along a first direction (the first direction is indicated by arrows in fig. 4 and 5) and has a first end surface 11 and a second end surface 12 opposite to each other, and the rotor core 10 is disposed on at least a portion of the mounting portion 21. The rotor core 10 is made of a metal material having a high saturation magnetic induction to increase the intensity of electromagnetic induction, and is made of a silicon steel sheet. Further, the rotor core 10 is fitted to the fitting portion 211, and the positioning portion 212 can abut against one end surface of the rotor core 10 in the first direction. The positioning portion 212 is specifically abutted with the rotor core 10, or abutted with the end ring 30 of the squirrel cage assembly 1, and can be set according to actual requirements. The plurality of conducting bars 20 are arranged at intervals along the circumferential direction of the rotor core 10, and penetrate through the rotor core 10, that is, the conducting bars 20 are arranged at intervals around the first direction, each conducting bar 20 penetrates through the rotor core 10,

the end rings 30 are provided in two numbers, and the end rings 30 are respectively disposed on both sides of the rotor core 10 and are fixedly connected to the bars 30. Specifically, the two end rings 30 are a first end ring 301 and a second end ring 302, respectively. The first end ring 301 is located outside the rotor core 10, that is, the first end ring 301 is disposed outside a space surrounded by the outer contour of the rotor core 10. The first end ring 301 is disposed close to the first end face 11 with respect to the second end face 12 in the first direction, i.e., the first end ring 301 is spaced from the first end face 11 by a smaller distance than the first end ring 301 is spaced from the second end face 12. The second end ring 302 is located outside the rotor core, i.e. the second end ring 302 is disposed outside the space enclosed by the outer contour of the rotor core 10. The second end ring 302 is disposed proximate to the second end face 12 with respect to the first end face 11 in the first direction, i.e., the second end ring 302 is spaced from the second end face 12 by a smaller distance than the second end ring 302 is spaced from the first end face 11.

Specifically, the two end rings are obtained through additive manufacturing, the end rings are fixedly connected with the guide bars, specifically, the first end ring is fixedly connected with the parts of the guide bars, which extend out of the first end face of the rotor core, and the second end ring is fixedly connected with the parts of the guide bars, which extend out of the second end face of the rotor core. In the process of additive manufacturing, materials for manufacturing the first end ring and the second end ring are melted and then solidified, so that acting force for enabling the first end ring and the guide bar to be fixedly integrated is formed between the contact surfaces of the first end ring and the guide bar and between the contact surfaces of the second end ring and the guide bar, and the first end ring and the second end ring are respectively fixed on the guide bar instead of the first end ring and the second end ring which are manufactured through additive manufacturing, and good integrity is achieved between the two end rings and the guide bar. So, avoided using welded mode to carry out fixed connection to end ring and conducting bar, simultaneously, avoided the insufficient problem of welding.

In some embodiments, the end face of the conducting bar extending out of the rotor core is fixedly connected with the end ring, and the distance between the end ring and the end face of the rotor core is smaller than a preset value. That is, one end of the bar 20 protrudes from the first end surface 11 of the rotor core 10, the other end of the bar 20 opposite to the one protruding from the first end surface 11 protrudes from the second end surface 12, and both ends of the bar 20 are fixed to the end rings 30, respectively. And the distance between the first end ring 301 and the first end face 11 is smaller than a preset value, and the distance between the second end ring 302 and the second end face 12 is smaller than a preset value. The distance between the first end face 11 and the first end ring 301 is smaller than a preset value, and the distance between the second end face 12 and the second end ring 302 is smaller than a preset value, so that the movement of the rotor core 10 relative to the first end ring 301 and the second end ring 302 along the first direction is limited within a small range through the first end ring 301 and the second end ring 302, the integrity of the squirrel cage assembly is improved, the natural frequency of the squirrel cage assembly is optimized, the squirrel cage assembly is not easy to resonate with external excitation in the running process, the vibration is reduced, and the service life of the squirrel cage assembly is prolonged.

Specifically, in the first direction, a distance between each end face and the corresponding end ring is smaller than a preset value, specifically, a distance between the first end face and the first end ring is smaller than the preset value, and a distance between the second end face and the second end ring is smaller than the preset value, and optionally, the preset value may be 5 mm. The distance between the end face of the rotor core and the corresponding end ring is smaller than the preset value, so that the movement of the rotor core relative to the end ring along the first direction is limited in a small range through the end ring, the integrity of the squirrel cage assembly is improved, the natural frequency of the squirrel cage assembly is optimized, the squirrel cage assembly is difficult to resonate with external excitation in the running process, the vibration is reduced, and the service life of the squirrel cage assembly is prolonged. Meanwhile, the distance between the end surface of the rotor core and the corresponding end ring is smaller than the preset value, so that the noise generated by the squirrel cage assembly in the operation process can be reduced, and the principle of reducing the noise is explained below. The distance between the end ring of the relevant squirrel cage assembly and the end surface of the rotor core is larger, the length of the conducting bars exposed in the air between the end ring and the end surface of the rotor core is longer, and the conducting bars of the relevant squirrel cage assembly continuously stir the air in the rotating process, so that larger noise is generated; the end surfaces of the end rings and the corresponding rotor cores of the squirrel cage assembly provided by the embodiment are smaller than the preset threshold value, the length of the conducting bars exposed to the air between the end rings and the end surfaces of the rotor cores is shorter, and the capability of the conducting bars of the part of the conducting bars for stirring the air is weakened during the rotation of the squirrel cage assembly, so that the noise generated by the squirrel cage assembly during the operation process is reduced. It should be noted that, in the first direction, the design of the small distance between each end face and the corresponding end ring and the preset value can only be obtained by means of additive manufacturing, and specific reasons are described in other embodiments and are not described herein.

In some embodiments, the predetermined value is 5 mm, i.e., the first end ring 301 is spaced from the first end face 11 by less than 5 mm, and the second end ring 302 is spaced from the second end face 12 by less than 5 mm. Therefore, the distance of the rotor core 10 between the first end ring 301 and the second end ring 302 moving along the first direction is limited within 10 millimeters through the first end ring 301 and the second end ring 302, the integrity of the squirrel cage assembly is improved, the natural frequency of the squirrel cage assembly is optimized, the squirrel cage assembly is not easy to resonate with external excitation in the running process, vibration is reduced, and the service life of the squirrel cage assembly is prolonged.

In some embodiments, the first end ring 301 abuts the first end face 11 and the second end ring 302 abuts the second end face 12, i.e. the first end ring 301 is spaced from the first end face 11 by zero and the second end ring 302 is spaced from the second end face 12 by zero, such that the rotor core 10 cannot move in the first direction relative to the first end ring 301 and the second end ring 302 by the first end ring 301 and the second end ring 302, thereby further reducing vibrations caused by the movement of the rotor core 10 in the first direction relative to the first end ring 301 and the second end ring during operation of the squirrel cage assembly, thereby prolonging the service life of the squirrel cage assembly. Meanwhile, the first end ring 301 is abutted to the first end face 11, and the second end face 302 is abutted to the second end face 12, so that the length of the conducting bars exposed to the air between the corresponding end faces of the end ring and the rotor core can be further reduced, and even no conducting bars exposed to the air exist between the corresponding end faces of the end ring and the rotor core, so that the capacity of the conducting bars of the part for stirring the air is further reduced, and the noise generated in the rotating process of the squirrel cage assembly is further reduced.

In some embodiments, as shown in fig. 6 and 7 in combination, the end rings 30 each have a mounting groove 31, and the mounting grooves 31 are used for accommodating the connection part of the guide bars 20 and the end rings 30. That is, the first end ring 301 and the second end ring 302 each have a mounting groove 31, and the mounting groove 31 is used to receive one end of the guide bar 20 protruding out of the first end surface 11 in fig. 4 and the other end of the guide bar 20 protruding out of the second end surface 12 in fig. 5. As shown in fig. 6, taking the first end ring and the conducting bars close to the first end ring as an example, specifically, the first end ring 301 has a mounting groove 31, and one end of the conducting bars 20 protruding out of the first end surface 11 extends into the mounting groove 31 of the first end ring 301. By providing the mounting grooves 31 at the first end ring 301 and the second end ring 302, the contact area between the first end ring 301 and the guide bars 20 and the contact area between the second end ring 302 and the guide bars 20 are increased, thereby enabling the first end ring 30 to be more firmly fixed to the guide bars 20 and enabling the second end ring 302 to be more firmly fixed to the guide bars 20. Optionally, the length of the guide bar 20 extending into the mounting groove 50 is between 5 mm and 10 mm.

In some embodiments, as shown in fig. 6, the portion of the guide bar 20 located in the installation groove 31 is provided with a first limiting structure 201, and the wall surfaces of the first end ring 301 and the second end ring 302 adjacent to the installation groove 31 are provided with limiting parts 312. Specifically, the mounting groove 31 includes a supporting groove 311 and a limiting portion 312, the limiting portion 312 and the supporting groove 311 are formed integrally, the supporting groove 311 has an open end surface, so that the supporting groove 311 is disposed near the end surface of the end ring 30, the extending direction of the supporting groove 311 and the extending direction of the limiting portion 312 form a preset included angle, that is, the extending direction of the supporting groove 311 is different from the extending direction of the limiting portion 312, or the extending direction of at least a partial structure of the limiting portion 312 is different from the extending direction of the supporting groove 311, and the preset included angle may be 30 °, 60 °, or 90 °. It should be noted that the limiting portion 312 extends to a first position, and the first position is spaced from the opening end surface of the supporting groove 311 by a preset distance. The first position may be considered as a position to which at least a part of the stopper portion 312 extends, and the part of the stopper portion 312 at this position may be one surface or one point. The first position where the limiting portion 312 extends is spaced from the opening end surface of the support groove 311 by a preset distance, that is, the position of the limiting portion 312 on the support groove 311 is determined, so that the limiting portion 312 does not have an opening end surface or does not penetrate through the opening end surface of the support groove 311, that is, in the mounting groove 31, the limiting portion 312 has a characteristic different from the shape of the support groove 311 away from the opening end surface, so as to limit the movement of the end ring 30 in the depth direction relative to the guide bar 20, so that the guide bar 20 is stably connected with the end ring 30. As shown in fig. 6, the predetermined included angle is 90 degrees, the extending direction of the supporting groove 311 is a straight line and is parallel to the depth direction of the end ring 30, and the limiting portion 312 is disposed on the side surface of the supporting groove 311. The stopper 312 abuts against the first stopper structure 201 to restrict the movement of the first end ring 301 relative to the guide bar 20 and the movement of the second end ring 302 relative to the guide bar 20.

The design concept of the supporting groove and the limiting part provided in the present embodiment will be explained below. The installation groove has an irregular shape through the limitation of the positions and the structures of the limiting part and the supporting part, and the installation groove has poor economy or cannot be formed by adopting a cutting processing or pouring method, so that the installation groove is not suitable for use. Specifically, make the shape of mounting groove with the cutter into, carry out drilling processing to the end ring, because the drilling of cutter is backed out and is leaded to the drilling shape that finally obtains different with the cutter shape, can not obtain the mounting groove of this application through the cutter promptly. Or, the end ring of the present application is obtained by casting, and a core that is the same as the installation groove needs to be manufactured first, and then placed in the end ring model and cast, so that the end ring after cast cannot be taken out of the core, and the end ring with the installation groove of the present application cannot be obtained. The possibility of the problems can be reduced through additive manufacturing, specifically, the end ring is directly and fixedly connected with the guide bars in the additive manufacturing process, the end ring is not fixed on the guide bars after the end ring is obtained through additive manufacturing, and therefore the limiting structure of the end ring is matched with and abutted to the structure of the end parts of the guide bars. According to the structural shape of the end of the conducting bar, the end ring with the installation groove is formed by gradually increasing materials on the surface of the end of the conducting bar, so that the supporting groove and the limiting part can be obtained to limit the movement of the end ring relative to the conducting bar. In summary, based on the manufacturing method of cutting or casting the end ring in the prior art, a person skilled in the art cannot think that the limit structure of the present application is provided in the end ring by an additive manufacturing method, and further cannot think that the limit of the end ring is realized by providing the support portion and the limit portion.

The advantageous effects of the squirrel cage assembly to which the end ring of the embodiment of the present application is applied will be described below. The fixed connection between the conducting bars and the end rings may be insufficient, for example, insufficient welding in the related art, or insufficient force for fixedly connecting the end rings and the conducting bars due to insufficient melting and the like in the process of obtaining the end rings fixed with the conducting bars through additive manufacturing, so that the end rings may be separated from the conducting bars under the action of external load during the operation of the squirrel cage assembly, and at the moment, other parts of the squirrel cage assembly may be damaged by being thrown out of the conducting bars during high-speed rotation and colliding with other parts of the squirrel cage assembly, and even may be thrown out of the outside of the motor shell, thereby threatening the personal safety of people around the motor. Through setting up spacing portion for the conducting bar can prevent that end ring and conducting bar from taking place relative motion under the effort with the mutual butt of spacing portion, from the conducting bar departure, sets up the security that spacing portion has improved the squirrel cage subassembly, thereby has improved the steadiness of being connected of conducting bar and end ring. Through set up supporting groove and spacing portion on the end ring for the gib block can stretch into limit structure in and with spacing portion butt, with the motion of the relative gib block of restriction end ring, increased the connected stability of gib block and end ring. Meanwhile, by providing the first position-limiting structure 201 and the position-limiting portion 312, the contact area between the end ring and the guide bar can be further increased, so that the end ring can be more stably fixed to the guide bar.

In some embodiments, as shown in fig. 6, the first position-limiting structure 201 is a position-limiting groove, the position-limiting portion 312 is a position-limiting boss, and at least a portion of the position-limiting boss is located in the first position-limiting structure 201 (position-limiting groove), so that the end ring 30 is prevented from being ejected from the conducting bar 20 by the abutting force between the first position-limiting structure 201 (position-limiting groove) and the position-limiting portion 312 (position-limiting boss), and the safety of the squirrel cage assembly is improved.

In some embodiments, as shown in fig. 7, the first position-limiting structure 201 is a position-limiting boss, and the position-limiting portion 312 is a position-limiting groove, that is, on the basis of the supporting groove 311, the groove area of the position-limiting structure 31 is increased, and the position-limiting groove extends from the side surface of the supporting groove 311 to a first position, which is a position outside the supporting groove 311. The stopper groove shown in fig. 7 is provided in a direction perpendicular to the extending direction of the support groove 311, and the end of the bar 20 has an abutting portion 21 having the same structure as the stopper groove. Thus, the end of the conducting bar 20 can be effectively abutted against the limiting groove, and the abutting force of the limiting groove and the conducting bar 20 can effectively limit the movement of the end ring 30 relative to the conducting bar 20, so that the connection stability of the conducting bar 20 and the end ring 30 is enhanced. The contact area between the end ring 30 and the lead bar 20 is further increased by the provision of the stopper groove as compared with the case where only the support groove 311 is provided to abut against the lead bar 20.

In some embodiments, as shown in fig. 8, the rotor core 10 is provided with a positioning slot 13, and the positioning slot 13 extends from the first end face 11 to the second end face 12 in fig. 5. A portion of the bar 20 is positioned in the positioning groove 13, thereby facilitating assembly of the bar 20 with the rotor core 10. Alternatively, the outer contour of the positioning slot 13 in a cross section perpendicular to the first direction coincides with the outer contour of the bar 20 in a cross section perpendicular to the first direction, thereby further facilitating the assembly between the bar 20 and the rotor core 10. Optionally, the number of the positioning slots 13 is equal to the number of the conducting bars 20, and the positioning slots 13 are arranged on the rotor core 10 at intervals around the first direction.

An embodiment of the present invention further provides a method for manufacturing a motor rotor, as shown in fig. 9, including:

s1: processing to obtain the squirrel cage assembly, wherein the processing comprises additive manufacturing and material reduction manufacturing, and the material reduction manufacturing can be any one or more of a plurality of processing modes such as turning, milling, planing, grinding and the like;

s2: obtaining a motor rotating shaft through additive manufacturing;

s3: the squirrel cage component is sleeved on the rotating shaft of the motor.

As shown in fig. 10, step S1 includes:

step S101, processing to obtain a conducting bar and a rotor core, wherein the rotor core is provided with two end faces opposite to each other in the first direction.

The conducting bar may be obtained by any processing method, and the processing method of the conducting bar may be forging or roll forming, for example. The rotor core is made of a metal material with high saturation magnetic induction for enhancing the electromagnetic induction intensity of the squirrel cage assembly, and the metal material can be silicon steel. Alternatively, the rotor core is formed by laminating and fixing a plurality of layers of metal sheets with high saturation magnetic induction intensity, and the metal sheets can be silicon steel sheets, for example.

And S102, enabling the conducting bars to penetrate through the rotor core along the first direction and protrude outwards from the two end faces.

Specifically, the conducting bar has a first end and a second end opposite to each other along the first direction, after the conducting bar penetrates through the rotor core, the first end of the conducting bar protrudes from the first end face of the rotor core, and the second end of the conducting bar protrudes from the second end face of the rotor core. The guide bars are provided with a plurality of guide bars which are arranged at intervals in the circumferential direction along the first direction and penetrate through the rotor core along the first direction.

And step S103, obtaining a corresponding end ring close to each end face through additive manufacturing.

Specifically, the two end rings are obtained through additive manufacturing, the end ring close to the first end face of the rotor core is a first end ring, and the end ring close to the second end face of the rotor core is a second end ring, that is, the distance between the first end ring and the first end face is smaller than the distance between the second end ring and the first end face, and the distance between the second end ring and the second end face is smaller than the distance between the second end ring and the first end face.

The end rings are fixedly connected with the guide bars, specifically, the first end ring is fixedly connected with the parts of the guide bars, which extend out of the first end surface of the rotor core, and the second end ring is fixedly connected with the parts of the guide bars, which extend out of the second end surface of the rotor core. It should be noted that, the first end ring and the second end ring are fixedly connected with the guide bars in the additive manufacturing process, instead of obtaining the first end ring and the second end ring through additive manufacturing, and then the first end ring and the second end ring are respectively fixed on the guide bars, so that the two end rings and the guide bars have good integrity.

The following is a description of the principle by which the pitch between the rotor core and the corresponding end ring can be reduced using an additive manufacturing method. In the manufacturing method of the squirrel-cage assembly, the rotor core, the conducting bars and the end rings need to be obtained firstly, and then the rotor core, the conducting bars and the end rings are spliced at preset positions so as to obtain the squirrel-cage assembly, in the assembling process, the sizes of the rotor core, the guide bars and the end rings cannot be changed, the distance between the end surface of the rotor core and the corresponding end ring is influenced by the manufacturing error of the rotor core, the manufacturing error of the end ring and the assembling error, the distance between the end surface of the rotor core and the corresponding end ring can float in a larger range, the distance between the end surface of the rotor core and the corresponding end ring needs to be larger to prevent the assembling interference between the rotor core and the end ring, and simultaneously, in the related method of manufacturing the squirrel cage assembly, the end rings and the bars are fixed by welding, and a large distance between the end rings and the end surfaces of the rotor core is also required in order to reduce the influence of high temperature generated during welding on the rotor core. In the manufacturing method of the squirrel-cage assembly provided by the embodiment of the invention, the conducting bars and the rotor core are assembled, and then two end rings corresponding to two end surfaces of the rotor core are obtained through additive manufacturing according to the actual position of the end surface of the rotor core. The end ring is manufactured by taking the actual position of the end face of the rotor core as a reference, so that the influence of the manufacturing error of the rotor core and the assembly error of the rotor core and the guide bar on the distance between the end face of the rotor core and the corresponding end ring is reduced, and the distance between the end face of the rotor core and the corresponding end ring is mainly influenced by the size of the end ring and the size error of the end ring; meanwhile, the end ring is obtained through additive manufacturing, the size of the end ring can be adaptively adjusted according to the actual position of the end face of the rotor core, and the additive manufacturing is a manufacturing method with higher precision, namely, the size of the end ring can be adaptively adjusted according to the actual position of the end face of the rotor core, and the size error of the end ring is smaller, so that the distance between the end face of the rotor core and the corresponding end ring floats in a smaller range, and the distance between the end face of the rotor core and the corresponding end ring is reduced on the premise that the rotor core and the end ring are not subjected to assembly interference. It should be noted that, the fixing of the conducting bars and the end rings by welding requires consumption of solder and flux, the solder is generally expensive silver solder, and the end rings fixed with the conducting bars are directly formed on the conducting bars by additive manufacturing, so that the solder and the flux can be saved, and the cost of consumables used in the manufacturing process of the squirrel cage assembly can be reduced.

In the processing procedure of the squirrel cage assembly, after the conducting bars and the rotor core are processed and assembled, the end rings are manufactured according to the actual positions of the end faces of the rotor core, the influence of the manufacturing errors of the rotor core and the conducting bars on the distance between the end faces of the rotor core and the corresponding end rings is reduced, meanwhile, the end rings are obtained through additive manufacturing, the size of the end rings can be adjusted adaptively according to the actual positions of the rotor core, the size of the end rings is enabled to have higher precision, the floating range of the distance between the end faces of the rotor core and the corresponding end rings is reduced, and then the distance between the end faces of the rotor core and the corresponding end rings can be smaller than a preset value on the premise that the rotor core and the end rings do not generate assembly interference. The distance between the end face of the rotor core and the corresponding end ring is smaller than the preset value, so that the movement of the rotor core relative to the end ring along the first direction is limited within a small range through the end ring, the integrity of the squirrel cage assembly is improved, the natural frequency of the squirrel cage assembly is optimized, the squirrel cage assembly is difficult to resonate with external excitation in the running process, the vibration is reduced, and the service life of the squirrel cage assembly is prolonged. Meanwhile, the distance between the end face of the rotor core and the corresponding end ring is smaller than a preset threshold value, and noise generated by the squirrel cage assembly in the running process can be reduced.

In some embodiments, the end rings can be machined by additive manufacturing in any order along the first direction. Optionally, the end ring corresponding to the end face is formed by additive manufacturing from the end of the conducting bar to a preset position close to the corresponding end face along the first direction, wherein a distance between the preset position and the first end face is smaller than a preset value. Specifically, along a first direction, a first end ring corresponding to a first end face is formed from the end part of the guide bar extending out of the first end face to a preset position close to the first end face through additive manufacturing; and forming a second end ring corresponding to the second end face by additive manufacturing from the end part of the guide bar extending out of the second end face to a preset position close to the second end face along the first direction. Alternatively, the end ring corresponding to the end face of the rotor core is formed by additive manufacturing from the end face to the end of the guide bar in the first direction. Specifically, in the first direction, a first end ring corresponding to the first end face is formed by additive manufacturing from the first end face of the rotor core to the end of the part of the conducting bar, which extends out of the first end face; and forming a second end face corresponding to the second end face by additive manufacturing from the second end face of the rotor core to the end part of the conducting bar, which extends out of the second end face, along the first direction.

In some embodiments, as shown in fig. 11, the present embodiment provides a method for manufacturing a squirrel cage assembly different from the method for manufacturing the squirrel cage assembly shown in fig. 1 in that step S103 in fig. 10 includes:

step S201, forming a corresponding end ring by additive manufacturing from each end face outwards in a first direction.

Specifically, along the first direction, the first end ring is obtained by additive manufacturing from the first end face of the rotor core to a direction away from the first end face, and the second end ring is obtained by additive manufacturing from the second end face of the rotor core to a direction away from the second end face. The end part of the rotor core is directly used as a starting base surface for additive manufacturing, so that the distance between the end ring obtained by additive manufacturing and the end surface of the corresponding rotor core is zero, namely, the end ring can abut against the end surface of the corresponding rotor core, the movement of the rotor core relative to the end ring along the first direction is further reduced, and the vibration caused by the movement of the rotor core relative to the end ring along the first direction during the operation of the squirrel cage assembly is further reduced, and the service life of the squirrel cage assembly is further prolonged.

Wherein one side of the end ring is located outside the bars, i.e. the additive manufactured end ring, extends in a first direction from the corresponding end surface of the rotor core in a direction away from the end surface until extending beyond the corresponding end portion of the bars. Specifically, the first end ring obtained by additive manufacturing extends from the first end face of the rotor core to a direction far away from the first end face along the first direction until the first end extends beyond the first end of the conducting bar, and the first end is the end of the part of the conducting bar protruding out of the first end face; and the second end ring is obtained by additive manufacturing, extends from the second end face of the rotor core to a direction far away from the second end face along the first direction until the second end extends beyond the second end of the conducting bars, and the second end is the end of the part of the conducting bars protruding out of the second end face. Wherein the first end ring extends in the first direction to a first predetermined position beyond the first end of the conducting bar, the first predetermined position being spaced from the first end of the conducting bar by a predetermined distance, which may be, for example, 5 mm; the second end ring extends in the first direction to a second predetermined position beyond the second end of the bar, the second predetermined position being spaced from the second end of the bar by a predetermined distance, which may be, for example, 5 mm. In the end ring obtained by additive manufacturing, a force for fixing the end ring and the guide bar is applied between the contact surfaces of the end ring and the guide bar due to melting of the material, and the connection between the end ring and the guide bar is more stable as the contact area between the end ring and the guide bar is larger. By enabling the end ring to extend to the outer side of the guide bar from the end part of the rotor core along the first direction, the size of the part, extending out of the end face of the rotor core, of the guide bar along the first direction is fully utilized to increase the contact area of the end ring and the guide bar, so that the connection between the end ring and the guide bar is more stable, and the conductivity between the guide bar and the end ring is improved.

Additive manufacturing may be a manufacturing process in which successive layers of material are provided on top of each other to build up a three-dimensional part layer by layer, with adjacent layers of material being fused between them to integrally form the integral part. It should be understood that additive manufacturing in embodiments of the present invention refers to manufacturing primarily by adding material during the manufacturing process, but that other processing steps may also be added to a particular manufacturing process, for example, layer addition processing, layer subtraction processing, or hybrid processing. The additive manufacturing may be performed by any one of a fused deposition modeling method, a selective laser sintering method, a stereolithography method, an electron beam sintering method, and the like.

In some embodiments, in order to more clearly illustrate the process of additive manufacturing to obtain the end ring, the following process of additive manufacturing by a selective laser sintering method is taken as an example in conjunction with fig. 12 to illustrate the manufacturing process of the end ring, and those skilled in the art will understand that the end ring can also be obtained by other additive manufacturing methods. The consolidation between the end rings and the conducting bars obtained by the selective laser sintering method is better, so that the squirrel cage assembly has higher structural strength.

As shown in fig. 12, the method for manufacturing the squirrel cage assembly according to the present embodiment is different from the method for manufacturing the squirrel cage assembly shown in fig. 11 in that step S201 in fig. 11 includes:

step S301: and spraying metal powder on the end surface of the rotor core, and sintering the metal powder to form a first cross section layer fixedly connected with the guide strip.

Specifically, according to the shape of the end ring, a predetermined portion of the metal powder is melted by a laser, and the melted metal powder is solidified to form the first cross-sectional layer. Meanwhile, in the process of laser sintering of the metal powder, the metal powder near the guide bar is melted, and the part of the metal powder is solidified and then is fixedly integrated with the outer surface of the guide bar, so that the first cross section layer is fixedly connected with the guide bar. It should be noted that, in this step, the metal powder is melted by the laser, but the thickness of the sprayed metal powder is thin, and only a predetermined portion of the metal powder needs to be melted, the time of the laser acting on the metal powder is short, and the influence of the heat generated by the laser on the end of the rotor core is small or even negligible.

Step S302, spraying metal powder onto the first cross-sectional layer and sequentially forming additional cross-sectional layers in order to consolidate the first cross-sectional layer and each of the additional cross-sectional layers to form an end ring.

Specifically, after the first cross-sectional layer is sintered, a preset part of metal powder is melted by laser according to the shape of an end ring, and the melted metal powder is solidified to form another cross-sectional layer. And repeating the steps of spraying metal powder on the newly formed cross-section layer and sintering the metal powder into another cross-section layer by laser according to the shape of the end ring from the end face of the rotor core to the direction far away from the end face along the first direction until the newly formed cross-section layer reaches the outer side of the guide strip, thereby obtaining the end ring by additive manufacturing.

It should be noted that one side of the end ring is located outside the bars, that is, the additive manufactured end ring extends from the corresponding end surface of the rotor core in the first direction to a direction away from the end surface until extending beyond the corresponding end portion of the bars. Specifically, the first end ring obtained by additive manufacturing extends from the first end face of the rotor core to a direction far away from the first end face along the first direction until the first end extends beyond the first end of the conducting bar, and the first end is the end of the part of the conducting bar protruding out of the first end face; and the second end ring is obtained by additive manufacturing, extends from the second end face of the rotor core to a direction far away from the second end face along the first direction until the second end extends beyond the second end of the conducting bars, and the second end is the end of the part of the conducting bars protruding out of the second end face. Wherein the first end ring extends in the first direction to a first predetermined position beyond the first end of the conducting bar, the first predetermined position being spaced from the first end of the conducting bar by a predetermined distance, which may be, for example, 5 mm; the second end ring extends in the first direction to a second predetermined position beyond the second end of the bar, the second predetermined position being spaced from the second end of the bar by a predetermined distance, which may be, for example, 5 mm. In the end ring obtained by additive manufacturing, a force for fixing the end ring and the guide bar is applied between the contact surfaces of the end ring and the guide bar due to melting of the material, and the connection between the end ring and the guide bar is more stable as the contact area between the end ring and the guide bar is larger. By enabling the end ring to extend to the outer side of the guide bar from the end part of the rotor core along the first direction, the size of the part, extending out of the end face of the rotor core, of the guide bar along the first direction is fully utilized to increase the contact area of the end ring and the guide bar, so that the connection between the end ring and the guide bar is more stable, and the conductivity between the guide bar and the end ring is improved.

In some embodiments, after one end ring is manufactured by additive manufacturing, the other end ring is manufactured by additive manufacturing, and after the end ring corresponding to one end face is manufactured, a limiting force which enables the end face of the rotor core to face the direction of the corresponding end ring is applied to the rotor core so as to reduce the relative movement between the rotor core and the formed end ring in the process of manufacturing the end ring corresponding to the other end face. Illustratively, a first end ring corresponding to the first end face of the rotor core is obtained through additive manufacturing, then a limiting force in the direction from the first end face to the first end ring is applied to the rotor core, and the limiting force is continuously applied while a second end ring corresponding to the second end face of the rotor core is obtained through additive manufacturing, so that relative movement between the rotor core and the first end ring is reduced in the process of obtaining the second end ring through additive manufacturing.

Optionally, when additive manufacturing is performed by selecting the laser sintering method, in order to reduce the influence of gravity on the additive manufacturing, the first end ring and the second end ring may be manufactured separately. Specifically, the rotor core is rotated to enable the first end face of the rotor core to be approximately parallel to the horizontal plane, and a first end ring is formed from the first end face to the outside in a first direction through additive manufacturing; after the first end ring is formed, the rotor core is rotated again so that the second end face of the rotor core is substantially parallel to the horizontal plane and a second end ring is formed by additive manufacturing from the second end face outwards in the first direction. The horizontal plane can be a plane of relatively completely static water, the horizontal plane is perpendicular to the direction of gravity, the first end face and the second end face are respectively approximately parallel to the horizontal plane in the process of obtaining the first end ring and the second end ring through additive manufacturing, so that the first end face can bear metal powder for forming the first end ring in the process of obtaining the first end ring through additive manufacturing, the second end face can bear metal powder for forming the second end ring in the process of obtaining the second end ring through additive manufacturing, and no other bearing structure needs to be additionally arranged.

As shown in fig. 13, step S2 specifically includes:

and S211, spraying metal powder with a preset thickness on the bearing base surface, and sintering the technical powder layer into a first section layer with a corresponding shape by laser according to the structure of the motor rotating shaft.

Specifically, in the design process, the motor rotating shaft is divided into a plurality of continuous design cross-section layers along the length direction of the motor rotating shaft according to the thickness of the cross-section layer formed by sintering each time through a laser sintering method, a first design cross-section layer is determined according to the manufacturing sequence of the design cross-section layers, and metal powder is sintered into the first cross-section layer with the shape consistent with that of the first design cross-section layer through laser. For example, if the cross-sectional layers of the motor rotor are sequentially formed from a first end of the motor rotor to a second end opposite to the first end in the first direction, the cross-sectional layer including the first end or the cross-sectional layer closest to the first end is determined as the first cross-sectional layer. It should be noted that the design cross-sectional layer is a virtual structure into which a model of the motor rotating shaft is cut during the design process, and the virtual structure is a manufacturing target in the additive manufacturing process rather than an actual structure.

Step S212, spraying metal powder on the first cross-section layer and sintering to sequentially form other cross-section layers, so that the first cross-section layer and each other cross-section layer are solidified to form the motor rotating shaft.

Optionally, each cross-sectional layer of the motor rotating shaft is sequentially manufactured from a first end of the motor rotor to a second end opposite to the first end along the first direction, and each adjacent cross-sectional layer is sequentially sintered into the motor rotating shaft with the shape consistent with that of the required motor rotating shaft, so that the integrally formed motor rotating shaft is obtained.

Optionally, after forming a cross-section layer by sintering, removing the excess metal powder on the cross-section layer, and after removing the excess metal powder, manufacturing the next cross-section layer to prevent the excess metal powder from affecting the manufacture of the next cross-section layer.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. An electric machine rotor, at least part of which is obtained by additive manufacturing, the electric machine rotor comprising:

the squirrel cage component and the motor rotating shaft are arranged on the motor;

wherein, the motor shaft includes:

the installation part extends along a first direction, a cavity is arranged in the installation part, and the squirrel cage assembly is sleeved on at least part of the installation part;

the transmission part is arranged at the end part of the mounting part and extends along the first direction;

in a cross section perpendicular to the first direction, the outer edge size of the mounting part is larger than that of the transmission part, and the ratio of the outer edge size of the mounting part to that of the transmission part is larger than a preset value.

2. An electric machine rotor as recited in claim 1, wherein the cavity is disposed within the drive portion.

3. The electric machine rotor of claim 2, wherein at least one of the cavity in the mounting portion and the cavity in the transmission portion comprises a closed cavity.

4. The electric machine rotor as recited in claim 1, wherein the mounting portion comprises:

the squirrel cage assembly is sleeved on the sleeving part, and the transmission part is arranged at the end part of the sleeving part;

the positioning part extends out of the circumferential outer surface of the sleeving part along a second direction and is abutted with one end of the squirrel cage assembly; wherein the second direction is substantially perpendicular to the first direction.

5. The electric machine rotor as recited in claim 4, wherein a distance by which the positioning portion protrudes from the circumferential outer surface of the sleeve portion is greater than a preset threshold.

6. The motor rotor as claimed in claim 4, wherein a heat dissipation air duct is formed on an outer surface of the sheathing part, and a length direction of the heat dissipation air duct is substantially parallel to the first direction.

7. The electric machine rotor as recited in claim 1, wherein the squirrel cage assembly comprises:

the rotor core extends along the first direction and is sleeved on at least part of the mounting part;

the guide bars are arranged at intervals along the circumferential direction of the rotor core and penetrate through the rotor core;

and the two end rings are respectively arranged on two sides of the rotor core and fixedly connected with the guide bars.

8. The electric machine rotor of claim 7, wherein the bars extend beyond the end face of the rotor core and are fixedly connected to the end ring, and the end ring is spaced from the end face of the rotor core by less than a predetermined amount.

9. An electric machine rotor, as claimed in claim 8, characterized in that said preset value is 5 mm.

10. An electric machine rotor as claimed in claim 7, in which both end rings have mounting slots for receiving portions of the bars to which the end rings are connected.

11. A method of manufacturing a rotor for an electric machine, the rotor comprising:

an end ring and a motor rotating shaft;

the manufacturing method comprises the following steps: the end ring and the motor shaft are obtained by additive manufacturing.