Rotor punched sheet having protrusions, electric motor rotor, electric motor, and power assembly

Abstract

Provided in the present application are a rotor punched sheet having protrusions, an electric motor rotor, an electric motor and a power assembly. The rotor punched sheet having protrusions comprises a center hole and a plurality of through holes, wherein the plurality of through holes are arranged around the center hole. The dimension of each through hole in a first direction is smaller than that of each through hole in a second direction, and each through hole comprises two hole walls, which are oppositely arranged in the first direction. One hole wall of one through hole comprises: a plurality of protrusions, which are spaced apart in the second direction, the length of each protrusion in the first direction being less than the spacing between the two hole walls; or a plurality of grooves, which are spaced apart in the second direction, each groove comprising a groove bottom and a groove opening, which are oppositely arranged in the first direction, and in the second direction, the dimension of the groove opening being greater than the dimension of the groove bottom. Since the hole wall is provided with the protrusions or grooves, gaps are formed between a magnet and the hole wall, thereby preventing the direct contact between the magnet and the hole wall, such that the phenomenon of a short circuit occurring between insulated punched sheets by means of the magnet is reduced, thereby reducing eddy current losses in an iron core, and thus the efficiency of an electric motor is improved.

Description

Rotor punching with protrusion, motor rotor, motor and power assembly

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on September 20, 2023, with application number 202322562442.2, and the priority of the Chinese patent application entitled "Rotor Punching with Protrusion, Motor Rotor, Motor and Power Assembly", all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of motors, and more particularly, to a rotor punching sheet with a protrusion, a motor rotor, a motor, and a power assembly. Background Art

[0003] In the production of permanent magnet synchronous motors, injection molding and glue potting processes are typically used to fill plastic material between the magnets and the magnet holes to secure the magnets in the radial direction of the motor. However, when injecting plastic into the magnet holes, there is often plastic between one side of the magnet and the rotor core punchings, while the other side of the magnet is in direct contact with the rotor core magnet hole. This causes the mutually insulated rotor core punchings to short-circuit through the magnets, thereby increasing eddy current losses in the rotor core and reducing motor efficiency.

[0004] Summary of the Invention

[0005] The present application provides a rotor punching with a protrusion, a motor rotor, a motor and a power assembly. The rotor punching with a protrusion can avoid direct contact between the magnet and the hole wall of the rotor that accommodates the magnet, reduce the phenomenon of short circuit between the mutually insulated rotor punchings through the magnet, thereby reducing the eddy current loss of the rotor core and improving the efficiency of the motor.

[0006] In a first aspect, a rotor punching with projections is provided. The rotor punching with projections includes a central hole and multiple through-holes, the multiple through-holes being arranged around the central hole. Each through-hole has a smaller dimension along a first direction than along a second direction, and each through-hole includes two hole walls arranged opposite each other along the first direction. One hole wall of a through-hole includes: a plurality of projections, the plurality of projections being spaced apart along the second direction, the length of each projection being less than the spacing between the two hole walls along the first direction; or a plurality of grooves, the plurality of grooves being spaced apart along the second direction, each groove including a groove bottom and a groove opening, the groove opening being larger than the groove bottom along the second direction.

[0007] By machining multiple protrusions spaced apart along a second direction on the wall of the through hole of the rotor punching, or by punching a through hole with multiple grooves spaced apart along the second direction on the wall of the rotor punching, the magnet is inserted into the through hole of the rotor punching along the axial direction of the motor, and multiple gaps spaced apart along the second direction are formed between the magnet and the wall of the through hole. In this way, on the one hand, after the injection molding glue is injected into the through hole of the motor rotor punching, it can flow along the gap between the magnet and the wall of the through hole and fill the gap between the magnet and the wall of the through hole, avoiding direct contact between the magnet and the wall of the through hole, reducing the phenomenon of short circuits between the mutually insulated rotor punchings through the magnet, thereby reducing eddy current losses in the rotor core and improving motor efficiency. On the other hand, the processing and assembly processes of the motor are simplified, reducing the production cost of the motor.

[0008] In addition, the size of the notch along the second direction is larger than the size of the groove bottom, that is, the cross section of the groove is trapezoidal, and the injection molding glue flows into the groove more easily along the inclined surface of the groove.

[0009] In one implementation, the two hole walls have the same number of protrusions, or the two hole walls have the same number of grooves, or the number of protrusions on one hole wall is the same as the number of grooves on the other hole wall. Accordingly, when the plastic injection molding compound is injected into the through-holes of the motor rotor punchings, the amount of plastic injection molding compound that enters each hole wall and the side surface of the adjacent magnet is relatively even, thereby reducing the dynamic imbalance of the motor rotor and reducing the cycle time and cost of dynamic balancing correction.

[0010] In one implementation, the size of each protrusion along the first direction is greater than the size along the second direction. Accordingly, when the magnet is inserted into the through hole of the rotor sheet along the axial direction of the motor, each protrusion can easily undergo elastic deformation along the direction in which the magnet is inserted into the through hole of the rotor sheet.

[0011] In one implementation, the depth of each groove in a hole wall along the first direction is smaller than the width along the second direction. Accordingly, after injecting plastic into the through hole of the rotor punching, the contact area between the plastic and the magnet can be increased, allowing the magnet to be securely inserted into the through hole of the rotor punching.

[0012] In one implementation, the multiple through holes include multiple through hole groups, and the number of the multiple through holes is a multiple of the number of the multiple through hole groups, wherein: the multiple through hole groups are arranged around the center hole, and at least one of two adjacent through hole groups along the circumference of the motor includes one through hole.

[0013] Only one of the two adjacent through-hole groups along the circumferential direction of the motor includes a through-hole. In this way, in the process of stacking multiple identical rotor punchings with protrusions to form a rotor core, it is only necessary to rotate one of the two adjacent rotor punchings with protrusions by a certain angle along the circumferential direction of the rotor punchings with protrusions, so that one of the two adjacent through-hole groups of one rotor punching with protrusions is connected to the other of the two adjacent through-hole groups of another adjacent rotor punching with protrusions along the axial direction of the rotor core. In this way, it is possible to achieve that each through-hole of multiple rotor punchings with protrusions connected along the axial direction of the motor forms a magnet hole that includes a protrusion, thereby simplifying the processing technology and production cost of the rotor punchings with protrusions.

[0014] Each of the two adjacent through-hole groups along the circumferential direction of the motor includes one through-hole. In this way, it is only necessary to connect each through-hole of two adjacent identical rotor punchings with protrusions along the axial direction of the motor along the circumferential direction of the rotor punchings with protrusions to complete the process of stacking multiple identical rotor punchings with protrusions to form the rotor core, thereby simplifying the assembly process of the rotor punchings with protrusions.

[0015] In a second aspect, a motor rotor is provided, wherein the rotor core of the motor rotor includes a plurality of rotor punchings without protrusions and a plurality of rotor punchings with protrusions as described in any one of the first aspect and the possible implementation methods of the first aspect, each rotor punching without protrusions includes a plurality of through holes, each through hole of each rotor punching without protrusions includes two hole walls arranged opposite to each other along a first direction, and the size of each through hole of the rotor punching without protrusions along the first direction is smaller than the size along the second direction.

[0016] The motor rotor provided in the embodiment of the present application has a protrusion or groove on the wall of the through hole of the raised rotor punching, so that a plurality of gaps spaced along the second direction are formed between the magnet and the wall of the through hole. In this way, after the injection molding glue is injected into the through hole of the motor rotor punching, it can flow along the gap between the magnet and the wall of the through hole and fill the gap between the magnet and the wall of the through hole, avoiding direct contact between the magnet and the wall of the through hole, reducing the phenomenon of short circuit between the mutually insulated rotor punchings through the magnet, thereby reducing the eddy current loss of the rotor core and improving the efficiency of the motor.

[0017] In one example, the distance between the two hole walls of each through hole in each rotor punching piece without protrusions is greater than the distance between each protrusion on one hole wall and the other hole wall in a through hole in a rotor punching piece with protrusions.

[0018] On one hand, the rotor core of the motor includes a plurality of rotor punchings without protrusions and a plurality of rotor punchings with protrusions. This eliminates the need to machine multiple protrusions spaced apart along the second direction on the wall of the through hole of each rotor punching, thereby preventing direct contact between the magnet and the hole wall, and reducing the production cost of the rotor core. On the other hand, because the spacing between the two hole walls of each through hole in each rotor punching without protrusions is greater than the spacing between each protrusion on one hole wall and the other hole wall of a through hole in a rotor punching with protrusions, multiple gaps can be formed between each hole wall of each through hole in each rotor punching and the magnet.

[0019] In another example, the distance between the two hole walls of each through hole in each rotor punching piece without protrusions is smaller than the distance between each groove in one hole wall and the other hole wall of a through hole in a rotor punching piece with protrusions.

[0020] On one hand, the rotor core of the motor includes a plurality of rotor punchings without protrusions and a plurality of rotor punchings with protrusions. This eliminates the need to punch a through hole with a plurality of grooves spaced apart along a second direction in each rotor punching, thereby preventing direct contact between the magnet and the hole wall and reducing the production cost of the rotor core. On the other hand, because the spacing between the two hole walls of each through hole in each rotor punching without protrusions is smaller than the spacing between each groove and the other hole wall of a through hole in a rotor punching with protrusions, each hole wall of each through hole in each rotor punching can form multiple gaps with the magnet.

[0021] In one implementation, multiple rotor laminations with projections are arranged axially between two rotor laminations without projections. Accordingly, the ends of the rotor core are all rotor laminations without projections. This ensures that the projections in the through-holes of the rotor laminations with projections do not extend axially beyond the ends of the rotor core after elastic deformation, thus ensuring the flatness of the rotor core end surface.

[0022] In one implementation, one or more rotor punches without protrusions are arranged between two rotor punches with protrusions.

[0023] The presence of a blank rotor sheet between two protruding rotor sheets provides space for each protrusion to elastically deform in the direction of the magnet's insertion through-hole in the rotor sheet. This allows each protrusion to provide elastic restoring force to the magnet and abut against it, allowing the magnet to be inserted into the through-hole in the rotor sheet. Furthermore, by arranging another blank rotor sheet between the two protruding rotor sheets, the positions of the two protrusions, which are arranged consecutively and spaced along the motor's axial direction, abutting the magnet are closer, thereby better securing the magnet.

[0024] In one implementation, the number of non-protrusion rotor punches between two non-protrusion rotor punches is greater than the number of protrusion-bearing rotor punches between the two non-protrusion rotor punches. Accordingly, with fewer protrusion-bearing rotor punches, the magnets can be inserted into the through-holes of the rotor punches without contact with the walls of the through-holes, thereby reducing the production cost of the rotor core.

[0025] In one implementation, the number of rotor punchings with protrusions is smaller than the number of rotor punchings without protrusions. Accordingly, with fewer rotor punchings with protrusions, the magnets can be inserted into the through-holes of the rotor punchings without contact with the walls of the through-holes, thereby reducing the production cost of the rotor core.

[0026] In a third aspect, a motor is provided, comprising a motor rotor and a plurality of magnets as described in any one of the third aspect and any possible implementation of the third aspect, each magnet comprising two side surfaces arranged opposite to each other along a first direction, a hole wall of a through hole with a protruding rotor punching and a side surface of a magnet accommodated in the through hole being arranged adjacent to each other along the first direction, and a plurality of gaps arranged between a hole wall and a side surface at intervals along a second direction.

[0027] The motor provided in the embodiment of the present application has a protrusion or groove on the wall of the through hole of the raised rotor punching, so that a plurality of gaps spaced along the second direction are formed between the magnet and the wall of the through hole. In this way, after the injection molding glue is injected into the through hole of the rotor punching of the motor, it can flow along the gap between the magnet and the wall of the through hole and fill the gap between the magnet and the wall of the through hole, avoiding direct contact between the magnet and the wall of the hole, reducing the phenomenon of short circuit between the mutually insulated rotor punchings through the magnet, thereby reducing the eddy current loss of the rotor core and improving the efficiency of the motor.

[0028] In one implementation, the length of each protrusion along the first direction is less than the size of a magnet along the first direction. While ensuring sufficient magnetic field strength in the motor, the size of each protrusion along the first direction does not need to be excessively large, thereby ensuring a gap between the wall of the through hole in the rotor punching and the magnet, thereby preventing direct contact between the magnet and the wall.

[0029] In one implementation, the dimension of each protrusion along the first direction is greater than the dimension of each gap along the first direction. Accordingly, when the magnet is inserted into the through-hole of the rotor sheet along the axial direction of the motor, because the dimension of each protrusion along the first direction is greater than the dimension of each gap along the first direction, each protrusion can elastically deform in the direction of insertion of the magnet into the through-hole of the rotor sheet, providing an elastic restoring force to the magnet through the side surface of the magnet and causing it to abut against the magnet.

[0030] In one implementation, the protrusions of the plurality of protrusion-bearing rotor punchings are bent axially along the motor. When a magnet is inserted axially into a through-hole in the rotor punching, each protrusion is capable of elastically deforming along the motor's axial direction, providing elastic restoring force to the magnet and abutting against the magnet, allowing the magnet to be inserted into the through-hole in the rotor punching.

[0031] In one implementation, the two hole walls of a through hole of a rotor punching with a protrusion respectively include multiple protrusions, and in the two hole walls: the multiple protrusions of one hole wall and the multiple protrusions of the other hole wall are respectively arranged relative to each other along a first direction, and the interval between the two protrusions of the two adjacent hole walls along the first direction is smaller than the size of a magnet along the first direction.

[0032] Because the multiple protrusions on one hole wall and the multiple protrusions on the other hole wall are arranged relative to each other along the first direction, on the one hand, when the injection molding compound is injected into the through-hole of the motor rotor punching, the flow resistance between each hole wall and the side of the adjacent magnet is relatively uniform, making the injection molding process more stable. On the other hand, the position where each protrusion on one of the two hole walls of a through-hole contacts the magnet and the position where each protrusion on the other hole wall contacts the magnet are located in a nearly straight line along the first direction. Consequently, the two protrusions aligned along the first direction can clamp the magnet, preventing the magnet from tilting or shifting along the first direction.

[0033] In addition, in the process of inserting the magnet into the through hole of the rotor punching along the axial direction of the motor, since the interval between the two protrusions of the two adjacent hole walls along the first direction is smaller than the size of a magnet along the first direction, each protrusion in the two hole walls can be elastically deformed along the direction of the magnet being inserted into the through hole of the rotor punching, and the two side surfaces of the magnet provide elastic restoring force to the magnet and abut the magnet, so that the magnet will not tilt or offset in the through hole of the rotor punching, reducing the probability of the magnet falling off from the through hole of the rotor punching, and facilitating the transportation of the motor rotor.

[0034] In one implementation, the two hole walls of a through hole of a protruding rotor punching respectively include multiple grooves, and in the two hole walls: the multiple grooves of one hole wall and the multiple grooves of the other hole wall are respectively arranged relatively spaced apart along a first direction, and the spacing between the two grooves of the two hole walls arranged relatively spaced apart along the first direction is greater than the size of a magnet along the first direction.

[0035] Because the multiple grooves of one hole wall and the multiple grooves of the other hole wall are arranged relative to each other along the first direction, when the injection molding compound is injected into the through-hole of the rotor punching of the motor, the flow resistance between each hole wall and the side surface of the adjacent magnet is relatively even, making the injection molding process more stable. In addition, because the spacing between the two grooves of the two hole walls arranged relative to each other along the first direction is greater than the size of a magnet along the first direction, there is a gap between each hole wall and the side surface of the adjacent magnet. In this way, when the injection molding compound is injected into the through-hole of the rotor punching of the motor, it is possible to avoid direct contact between one of the two hole walls and the side surface of the adjacent magnet due to the influence of gravity.

[0036] In a fourth aspect, a power assembly is provided, which includes a reducer or a transmission and a motor as described in any one of the third aspect and any possible implementation methods of the third aspect. The motor also includes a motor shaft, and the rotor core is sleeved on the motor shaft. The motor shaft is transmission-connected to the input shaft of the reducer or the input shaft of the transmission.

[0037] In a fifth aspect, an electric vehicle is provided, which includes wheels, a transmission mechanism, and the powertrain as described in the fourth aspect, wherein the powertrain drives the wheels through the transmission mechanism.

[0038] The technical effects of the fourth aspect or the fifth aspect mentioned above can refer to the corresponding description in the third aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG1 is a schematic structural diagram of an electric vehicle provided in an embodiment of the present application.

[0040] FIG2 is a schematic diagram of an exploded structure of a motor provided in an embodiment of the present application.

[0041] 3 to 7 are schematic structural diagrams of rotor punchings with protrusions provided in embodiments of the present application.

[0042] FIG8 is a schematic structural diagram of a rotor punching without protrusions provided in an embodiment of the present application.

[0043] 9 to 11 are schematic diagrams of the assembly structure of a magnet and a plurality of rotor punchings provided in embodiments of the present application.

[0044] FIG12 is a schematic cross-sectional view of a rotor according to an embodiment of the present application.

[0045] FIG13 is an enlarged schematic diagram of portion A of the rotor shown in FIG12 .

[0046] 14 and 15 are schematic structural diagrams of rotor punchings with protrusions provided in embodiments of the present application.

[0047] FIG16 is a schematic diagram of an exploded structure of another motor provided in an embodiment of the present application.

[0048] FIG17 is a schematic diagram of the structure of a magnet provided in an embodiment of the present application.

[0049] FIG18 is a schematic cross-sectional view of the rotor of the motor shown in FIG16 .

[0050] FIG19 is an enlarged schematic diagram of portion B of the rotor shown in FIG18 .

[0051] FIG20 is a schematic diagram of the assembly structure of the magnet shown in FIG17 and a plurality of rotor punchings provided in an embodiment of the present application. DETAILED DESCRIPTION

[0052] The technical solution in this application will be described below with reference to the accompanying drawings.

[0053] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in this article is merely a way to describe the association relationship of associated objects, indicating that three relationships can exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0054] The terms "upper", "lower", "inside", "outside", etc. in the embodiments of the present application indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present application.

[0055] References to "some embodiments" and the like in this specification mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in some embodiments" and the like that appear in different places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0056] The terms "equal" and "equal to" used in this application are not strictly equal, but rather fall within an acceptable error range. The terms "parallel" and "perpendicular" are not strictly parallel, but rather fall within an acceptable error range. The terms "perpendicular" and "perpendicular" are not strictly perpendicular, but rather fall within an acceptable error range.

[0057] In the embodiments of this application, the same reference numerals represent the same component or part. In the embodiments of this application, for multiple identical parts, only one of the parts may be labeled with a reference numeral in the drawings as an example. The same reference numerals apply to other identical parts or components. In addition, the sizes and dimensions of the parts shown in the drawings are for illustrative purposes only.

[0058] An embodiment of the present application provides a rotor punch with protrusions, comprising a central hole and a plurality of through-holes arranged around the central hole. Each through-hole has a smaller dimension along a first direction than along a second direction, and each through-hole comprises two hole walls arranged oppositely along the first direction. One hole wall of a through-hole comprises: a plurality of protrusions, the plurality of protrusions being spaced apart along the second direction, the length of each protrusion being less than the spacing between the two hole walls along the first direction; or a plurality of grooves, the plurality of grooves being spaced apart along the second direction, each groove comprising a groove bottom and a groove opening arranged oppositely along the first direction, the groove opening being larger than the groove bottom along the second direction.

[0059] By machining multiple protrusions spaced apart along a second direction on the wall of the through hole of the rotor punching, or by punching a through hole with multiple grooves spaced apart along the second direction on the wall of the rotor punching, the magnet is inserted into the through hole of the rotor punching along the axial direction of the motor, and multiple gaps spaced apart along the second direction are formed between the magnet and the wall of the through hole. In this way, on the one hand, after the injection molding glue is injected into the through hole of the motor rotor punching, it can flow along the gap between the magnet and the wall of the through hole and fill the gap between the magnet and the wall of the through hole, avoiding direct contact between the magnet and the wall of the through hole, reducing the phenomenon of short circuits between the mutually insulated rotor punchings through the magnet, thereby reducing eddy current losses in the rotor core and improving motor efficiency. On the other hand, the processing and assembly processes of the motor are simplified, reducing the production cost of the motor.

[0060] In addition, the size of the notch along the second direction is larger than the size of the groove bottom, that is, the cross section of the groove is trapezoidal, and the injection molding glue flows into the groove more easily along the inclined surface of the groove.

[0061] An embodiment of the present application also provides a motor rotor, the rotor core of the motor rotor includes a plurality of rotor punchings without protrusions and a plurality of rotor punchings with protrusions as described above, each rotor punching without protrusions includes a plurality of through holes, each through hole of each rotor punching without protrusions includes two hole walls arranged opposite to each other along a first direction, and the size of each through hole of the rotor punching without protrusions along the first direction is smaller than the size along the second direction.

[0062] In one example, the distance between the two hole walls of each through hole in each rotor punching piece without protrusions is greater than the distance between each protrusion on one hole wall and the other hole wall in a through hole in a rotor punching piece with protrusions.

[0063] On one hand, the rotor core of the motor includes a plurality of rotor punchings without protrusions and a plurality of rotor punchings with protrusions. This eliminates the need to machine multiple protrusions spaced apart along the second direction on the wall of the through hole of each rotor punching, thereby preventing direct contact between the magnet and the hole wall, and reducing the production cost of the rotor core. On the other hand, because the spacing between the two hole walls of each through hole in each rotor punching without protrusions is greater than the spacing between each protrusion on one hole wall and the other hole wall of a through hole in a rotor punching with protrusions, multiple gaps can be formed between each hole wall of each through hole in each rotor punching and the magnet.

[0064] In another example, the distance between the two hole walls of each through hole in each rotor punching piece without protrusions is smaller than the distance between each groove in one hole wall and the other hole wall of a through hole in a rotor punching piece with protrusions.

[0065] On one hand, the rotor core of the motor includes a plurality of rotor punchings without protrusions and a plurality of rotor punchings with protrusions. This eliminates the need to punch a through hole with a plurality of grooves spaced apart along a second direction in each rotor punching, thereby preventing direct contact between the magnet and the hole wall and reducing the production cost of the rotor core. On the other hand, because the spacing between the two hole walls of each through hole in each rotor punching without protrusions is smaller than the spacing between each groove and the other hole wall of a through hole in a rotor punching with protrusions, each hole wall of each through hole in each rotor punching can form multiple gaps with the magnet.

[0066] An embodiment of the present application also provides a motor, which includes the motor rotor described above and multiple magnets, each magnet including two side surfaces arranged opposite to each other along a first direction, a hole wall of a through hole with a raised rotor punching and a side surface of a magnet accommodated in the through hole are arranged adjacent to each other along the first direction, and multiple gaps are present between a hole wall and a side surface arranged at intervals along a second direction.

[0067] Due to the protrusions or grooves on the hole wall of the through hole with the protruding rotor punching, a plurality of gaps spaced along the second direction are formed between the magnet and the hole wall of the through hole. In this way, after the plastic glue is injected into the through hole of the rotor punching of the motor, it can flow along the gap between the magnet and the hole wall of the through hole and fill the gap between the magnet and the hole wall of the through hole, avoiding direct contact between the magnet and the hole wall, reducing the phenomenon of short circuit between the mutually insulated rotor punchings through the magnet, thereby reducing the eddy current loss of the rotor core and improving the efficiency of the motor.

[0068] The embodiment of the present application further provides an electric vehicle. The electric vehicle provided in the embodiment of the present application will be described in detail below with reference to FIG1 .

[0069] Figure 1 is a schematic diagram of the structure of an electric vehicle provided in an embodiment of the present application. As shown in Figure 1, the electric vehicle includes a battery 1, wheels 2, and one or more powertrains 3. The powertrain 3 is used to receive power from the battery 1 and drive the wheels 2, and the powertrain 3 is used to convert electrical energy into mechanical energy. The powertrain 3 includes a motor 30 and a reducer 31. The reducer 31 is in transmission connection with the motor 30. The reducer 31 is used to provide a transmission connection between the motor 30 and the wheels 2.

[0070] The electric vehicles provided in the embodiments of the present application include pure electric vehicles, hybrid electric vehicles, extended-range electric vehicles, plug-in hybrid electric vehicles or new energy vehicles, etc. Among them, pure electric vehicles are also called pure electric vehicle / battery electric vehicle, or simply pure EV / battery EV. Hybrid electric vehicles are also called hybrid electric vehicles, or simply HEV. Extended-range electric vehicles are also called range extended electric vehicles, or simply REEV. Plug-in hybrid electric vehicles are also called plug-in hybrid electric vehicles, or simply PHEV. New energy vehicles are also called new energy vehicles, or simply NEV.

[0071] In some embodiments, the powertrain 3 further includes a controller for controlling the start or stop, forward or reverse rotation, speed increase or decrease, drive torque increase or decrease, braking torque increase or decrease, etc. of the motor 30 .

[0072] The structure of the motor 30 provided in the embodiment of the present application is described in detail below with reference to FIG. 2 to FIG. 19 .

[0073] As shown in Figures 2 and 16, the motor 30 includes a motor shaft 310 and a rotor 320. The rotor 320 is used for transmission connection with the motor shaft 310. The rotor core of the rotor 320 includes at least one set of rotor punchings, and multiple sets of rotor punchings are arranged adjacent to each other along the axial direction of the motor 30. Each set of rotor punchings includes a plurality of rotor punchings 321 arranged along the axial direction of the motor 30. Each rotor punching 321 has a center hole O. The motor shaft 310 passes through the center hole O of each rotor punching 321, so that each rotor punching 321 is sleeved on the motor shaft 310.

[0074] Each rotor punching 321 further includes a plurality of through holes, which include a plurality of through hole groups 3211. The number of the plurality of through holes is a multiple of the number of the plurality of through hole groups 3211. Each through hole is not connected to the center hole O of the rotor punching 321, and the plurality of through holes are arranged around the center hole O of the rotor punching 321.

[0075] The rotor 320 also includes a plurality of magnets, which include a plurality of magnet groups 322. The number of the plurality of magnets is a multiple of the number of magnet groups 322. The plurality of through holes of two adjacent rotor punchings 321 are connected along the axial direction of the motor 30 to form a plurality of magnet holes, each of which is used to accommodate a magnet. The number of magnets included in each magnet group 322 is equal to the number of through holes included in each through hole group 3211. In the first direction, the size of a magnet is smaller than the size of the through hole accommodating the magnet, and in the second direction, the size of a magnet is smaller than the size of the through hole accommodating the magnet.

[0076] In one example, each magnet group 322 includes one magnet, and each through-hole group 3211 includes one through-hole.

[0077] In another example, each magnet group 322 includes three magnets, and each through-hole group 3211 includes three through-holes, which are arranged in two layers along the radial direction of the rotor punching 321. One layer of through-holes includes two through-holes arranged in a V-shape along the circumference of the rotor punching 321, and the other layer of through-holes includes one through-hole, which is arranged between the first layer of through-holes and the outer circumferential surface of the rotor punching 321.

[0078] In another example, each magnet group 322 includes four magnets, and each through-hole group 3211 includes four through-holes. Two through-holes form a layer of four through-holes, and the two through-holes are arranged in two layers along the radial direction of the rotor sheet 321. The two through-holes in each layer are arranged in a "V" shape along the circumference of the sheet 321. As shown in Figures 2, 12, 13, 16, 18, and 19, two of the four magnets include a magnet 322a and another magnet 322b, and the other two magnets include a magnet 322c and another magnet 322d. Two of the four through holes include one through hole 3211a and another through hole 3211b, and the other two through holes include one through hole 3211c and another through hole 3211d. The two through holes and the other two through holes are arranged in two layers along the radial direction of the rotor punching 321. One through hole 3211a and the other through hole 3211b of the two through holes are arranged in a "V" shape along the circumference of the punching 321, and one through hole 3211c and the other through hole 3211d of the other two through holes are arranged in a "V" shape along the circumference of the punching 321. As shown in Figures 2, 12, 13, 16, 18, and 19, the number of magnets in rotor 320 is 24, and the number of magnet groups 322 in rotor 320 is 6.

[0079] Each through hole of each rotor punching 321 includes two hole walls arranged oppositely in a first direction and another two hole walls arranged oppositely in a second direction. The size of each through hole in the first direction is smaller than the size in the second direction. As shown in Figures 2 to 6, 8, 12 to 14, 16, 18 and 19, the two hole walls of one through hole 3211a of the two through holes are respectively the right hole wall T a1 and left hole wall T a2 , the other two hole walls are upper hole wall T a3 and lower hole wall T a4 Each magnet includes two side surfaces arranged opposite to each other along a first direction and two other side surfaces arranged opposite to each other along a second direction. The size of each magnet along the first direction is smaller than the size along the second direction. As shown in FIG2, FIG16 and FIG17, the two side surfaces of the magnet 322a are the right side W a1 and left side W a2 , and the other two sides are upper side W a3 and lower side W a4 In addition, the size of each magnet along the first direction is smaller than the size of a through hole, and the size of each magnet along the second direction is smaller than the size of a through hole. In this way, each of the multiple magnet holes formed by connecting the multiple through holes of two adjacent rotor punchings 321 along the axial direction of the motor 30 can accommodate one magnet.

[0080] In some embodiments, the first direction is perpendicular to the second direction. The first direction can be understood as the width direction of the through hole or the height direction of the magnet, the second direction can be understood as the length direction of the through hole or the length direction of the magnet, and the axial direction of the motor 30 can be understood as the width direction of the magnet.

[0081] It should be noted that both the first direction and the second direction are relative to the position of a through-hole. The first and second directions may differ for different through-holes. For example, as shown in Figures 2 to 6, 8, 12 to 14, and 16 to 19, with respect to one through-hole 3211a of the two through-holes, the first direction is parallel to the x1 direction, and the second direction is parallel to the y1 direction. As shown in Figures 2 to 6, 8, 12 to 14, 16, 18, and 19, with respect to the other through-hole 3211b of the two through-holes, the first direction is parallel to the x2 direction, and the second direction is parallel to the y2 direction.

[0082] Along the first direction, one of the two hole walls of a through hole of a rotor punching 321 and one of the two side surfaces of a magnet accommodated in the through hole are adjacent to each other along the first direction, and there are a plurality of gaps arranged at intervals along the second direction between the hole wall and the side surface. For example, along the first direction, the right hole wall T of one of the two through holes 3211a is a1The right side W of one of the two magnets 322a a1 There are a plurality of gaps arranged in a spaced relationship along the second direction. The left hole wall T of one of the two through holes 3211a in the first direction is a2 The left side W of one of the two magnets 322a a2 There are multiple gaps spaced apart along the second direction. In this way, after the plastic injection glue is injected into the through-holes of the rotor punchings of the motor 30, it can flow along the gaps between the magnets and the hole walls of the through-holes and fill the gaps between the magnets and the hole walls of the through-holes, avoiding direct contact between the magnets and the hole walls of the through-holes. This reduces the phenomenon of short circuits between the multiple insulated rotor punchings 321 through the magnets, thereby reducing eddy current losses in the rotor core.

[0083] Exemplarily, multiple gaps spaced apart along the second direction between one of the two hole walls of a through hole in a rotor punching 321 and one of the two side surfaces of a magnet are formed by structures ①, ②, and ③. As shown in Figures 2 to 7 and 9 to 11, structure ① is a plurality of protrusions spaced apart along the second direction provided on at least one of the two hole walls of a through hole. By machining multiple protrusions spaced apart along the second direction on at least one hole wall of the through hole in the rotor punching 321, gaps spaced apart along the second direction are formed between the magnet and the hole wall of the through hole, simplifying the processing and assembly processes of the motor 30 and reducing the production cost of the motor 30. As shown in Figures 12 to 15, structure ② is a plurality of grooves spaced apart along the second direction provided on at least one of the two hole walls of a through hole. By punching a through hole with multiple grooves spaced along the second direction on the rotor punching 321, gaps spaced along the second direction are formed between the magnet and the hole wall, simplifying the processing and assembly process of the motor 30 and reducing the production cost of the motor 30. As shown in Figures 16 to 19, structure ③ is to provide multiple grooves spaced along the second direction on at least one of the two side surfaces of the magnet. By machining multiple grooves spaced along the second direction on at least one side surface of the magnet, multiple gaps spaced along the second direction are formed between the magnet and the hole wall, simplifying the processing and assembly process of the motor 30 and reducing the production cost of the motor 30.

[0084] It should be noted that structure ①, structure ② and structure ③ can be designed separately or in combination, and the embodiments of the present application do not limit this.

[0085] For ease of description, the rotor punchings 321 involved in the embodiments of the present application are divided into rotor punchings with protrusions and rotor punchings without protrusions. As shown in Figures 3 to 7 and Figures 9 to 11, at least one hole wall of at least one through hole of the rotor punching with protrusions includes multiple protrusions. As shown in Figures 12 to 15, at least one hole wall of at least one through hole of the rotor punching with protrusions includes multiple grooves. As shown in Figure 8, the hole walls of all through holes of the rotor punching 321e without protrusions do not include any protrusions or grooves.

[0086] In some embodiments, the rotor punchings 321 of the rotor core are all rotor punchings with protrusions. In other embodiments, the rotor punchings 321 of the rotor core include a plurality of rotor punchings with protrusions and a plurality of rotor punchings without protrusions.

[0087] The following describes structure ①, structure ② and structure ③ in detail respectively.

[0088] Structure ①: The hole wall of the through hole with the protruding rotor punch includes a protrusion

[0089] As shown in Figures 3 to 7 , the length of each protrusion along the first direction is less than the distance between the two walls of a through hole, and the width of each protrusion along the second direction is less than the size of a through hole. In this way, when the magnet is inserted into the magnet hole along the axial direction of the motor 30, the protrusions secure the magnet.

[0090] In some embodiments, as shown in Figures 9 to 11, the length of each protrusion along the first direction is less than the size of each magnet along the first direction. While ensuring sufficient magnetic field strength in the motor, the size of each protrusion along the first direction does not need to be excessively large, thereby achieving a gap between the hole wall of the through hole of the rotor punching 321 and the magnet, thereby preventing direct contact between the magnet and the hole wall.

[0091] In some embodiments, the dimension of each protrusion along the first direction is greater than the dimension of each gap along the first direction. Accordingly, when the magnet is inserted into the through-hole of the rotor sheet along the axial direction of the motor, because the dimension of each protrusion along the first direction is greater than the dimension of each gap along the first direction, each protrusion can elastically deform along the direction of insertion of the magnet into the through-hole of the rotor sheet, providing an elastic restoring force to the magnet through the side surface of the magnet and causing the magnet to abut.

[0092] In some embodiments, as shown in Figures 9 to 11 , each protrusion has a larger dimension along the first direction than along the second direction. Accordingly, when the magnet is inserted into the through hole of the rotor sheet along the axial direction of the motor, each protrusion can easily undergo elastic deformation along the direction in which the magnet is inserted into the through hole of the rotor sheet.

[0093] In one embodiment, only one of the two hole walls of each through hole of the rotor punching with protrusions includes multiple protrusions, thereby reducing the production cost of the rotor punching 321.

[0094] As shown in FIG3 , the left hole wall T of the two hole walls of each through hole with the protruding rotor punching 321 a is a2 It includes two protrusions, which are spaced apart along the second direction. a2 The two protrusions include a protrusion P11 and another protrusion P12. As shown in FIG4, the right hole wall T of the two hole walls of each through hole of the rotor punching 321b with protrusions a1 It includes two protrusions, which are spaced apart along the second direction. a1 The two protrusions include a protrusion P13 and another protrusion P14. Accordingly, the magnet can be fixed in the magnet hole by using less injection molding glue, thereby reducing the production cost of the motor 30.

[0095] In another embodiment, the two hole walls of each through hole of the rotor punching with protrusions include multiple protrusions, and in the two hole walls: the multiple protrusions of one hole wall and the multiple protrusions of the other hole wall are respectively arranged relative to each other along a first direction, and the interval between the two protrusions of the two adjacent hole walls along the first direction is smaller than the size of a magnet along the first direction, and the protrusions of the two hole walls are arranged at intervals along the first direction.

[0096] Because the multiple protrusions on one hole wall and the multiple protrusions on the other hole wall are arranged relative to each other along the first direction, on the one hand, when the injection molding compound is injected into the through-hole of the motor rotor punching, the flow resistance between each hole wall and the side of the adjacent magnet is relatively uniform, making the injection molding process more stable. On the other hand, the position where each protrusion on one of the two hole walls of a through-hole contacts the magnet and the position where each protrusion on the other hole wall contacts the magnet are located in a nearly straight line along the first direction. Consequently, the two protrusions aligned along the first direction can clamp the magnet, preventing the magnet from tilting or shifting along the first direction.

[0097] In addition, in the process of inserting the magnet into the through hole of the rotor punching along the axial direction of the motor, since the interval between the two protrusions of the two adjacent hole walls along the first direction is smaller than the size of a magnet along the first direction, each protrusion in the two hole walls can be elastically deformed along the direction of the magnet being inserted into the through hole of the rotor punching, and the two side surfaces of the magnet provide elastic restoring force to the magnet and abut the magnet, so that the magnet will not tilt or offset in the through hole of the rotor punching, reducing the probability of the magnet falling off from the through hole of the rotor punching, and facilitating the transportation of the motor rotor.

[0098] In one example, the number of protrusions on the two hole walls is equal. In this way, when the injection molding glue is injected into the through hole of the rotor punching of the motor, the amount of injection molding glue entering between each hole wall and the side of the adjacent magnet is relatively even, so that the dynamic imbalance of the motor rotor is small, thereby reducing the cycle and cost of dynamic balance correction. In addition, the projection of each protrusion of one hole wall of the two hole walls along the first direction overlaps with the projection of a protrusion of the other hole wall along the first direction. In other words, along the first direction, each protrusion of one hole wall of the two hole walls is aligned with a protrusion of the other hole wall. As shown in Figure 5, the right hole wall T of the two hole walls of each through hole of the rotor punching 321c with protrusions a1 and left hole wall T a2 Each includes two protrusions, and the two protrusions are spaced apart along the second direction. a2 The two protrusions include a protrusion P11 and another protrusion P12, and the right hole wall T a1 The two protrusions include a protrusion P13 and another protrusion P14. Thus, the position where each protrusion of one of the two hole walls of a through hole abuts the magnet and the position where each protrusion of the other hole wall abuts the magnet are located in almost a straight line along the first direction. Furthermore, the two protrusions aligned along the first direction can clamp the magnet, preventing the magnet from tilting or shifting along the first direction.

[0099] In another example, the number of protrusions on the two hole walls is different. For example, along the direction of gravity, the number of protrusions on the lower hole wall of a through hole is greater than the number of protrusions on the upper hole wall of a through hole. This prevents the magnet from directly contacting the lower hole wall of a through hole due to the influence of gravity. In this way, after injecting plastic into the magnet hole, it can avoid the influence of gravity causing too little plastic between the two protrusions on the lower hole wall of a through hole.

[0100] In some embodiments, at least one hole wall of each of two circumferentially adjacent through-hole groups of the motor includes multiple protrusions. As shown in FIG5 , each through-hole group 3211 of a rotor punching 321c with protrusions includes four through-holes, and each hole wall of the four through-holes of each through-hole group 3211 includes two protrusions. In this way, the rotor core can be formed by laminating multiple identical rotor punchings with protrusions simply by connecting each through-hole of two adjacent identical rotor punchings with protrusions along the circumference of the rotor punchings, along the axial direction of the motor. This simplifies the assembly process of the rotor punchings with protrusions.

[0101] In other embodiments, at least one hole wall of one of two adjacent through-hole groups along the circumference of the motor includes multiple protrusions, while each hole wall of the other through-hole group does not include any protrusions. As shown in FIG6 , each through-hole group 3211 of a rotor punching 321d with protrusions includes four through-holes. Each hole wall of the four through-holes in one of the two adjacent through-hole groups 3211 includes two protrusions, while each hole wall of the four through-holes in the other through-hole group does not include any protrusions. As shown in FIG7 , each through-hole group includes twelve through-holes. Each hole wall of the twelve through-holes in one of the two adjacent through-hole groups 3211 includes two protrusions, while each hole wall of the twelve through-holes in the other through-hole group does not include any protrusions. In this way, in the process of stacking multiple identical rotor punchings with protrusions to form a rotor core, it is only necessary to rotate one of the two adjacent rotor punchings with protrusions by a certain angle along the circumferential direction of the rotor punchings with protrusions, so that one of the two adjacent through-hole groups of one rotor punching with protrusions is connected to the other of the two adjacent through-hole groups of another adjacent rotor punching with protrusions along the axial direction of the rotor core, so that each magnet hole can include a protrusion, which simplifies the processing technology and production cost of the rotor punchings with protrusions.

[0102] In this embodiment, where the rotor core's multiple rotor punchings 321 include multiple protrusion-bearing and non-protrusion-bearing rotor punchings, the multiple protrusion-bearing rotor punchings are arranged between two non-protrusion-bearing rotor punchings along the axial direction of the motor 30. As shown in Figures 9 to 11, three protrusion-bearing rotor punchings 321c are arranged between two non-protrusion-bearing rotor punchings 321e. This ensures the flatness of the rotor core's end surface.

[0103] In some embodiments, multiple rotor punchings with projections are arranged at intervals along the axial direction of the motor 30, and one or more rotor punchings without projections are arranged between any two rotor punchings with projections arranged in sequence. As shown in FIG9 , three rotor punchings with projections 321c are arranged at intervals along the axial direction of the motor 30, and six rotor punchings without projections 321e are arranged between any two rotor punchings with projections 321c arranged in sequence. As shown in FIG10 , four rotor punchings with projections 321c are arranged at intervals along the axial direction of the motor 30, and three or four rotor punchings without projections 321e are arranged between any two rotor punchings with projections 321c arranged in sequence. As shown in FIG11 , six rotor punchings with projections 321c are arranged at intervals along the axial direction of the motor 30, and one or three rotor punchings without projections 321e are arranged between any two rotor punchings with projections 321c arranged in sequence.

[0104] In this way, it is ensured that during the process of inserting the magnet into the magnet hole along the axial direction of the motor 30, each protrusion can undergo elastic deformation along the direction of the magnet's insertion into the magnet hole, providing elastic restoring force to the magnet and abutting the magnet, so that the magnet is inserted into the magnet hole. In addition, arranging a rotor punch without a protrusion between any two rotor punches with protrusions arranged in sequence can make the positions of the two protrusions arranged in sequence in sequence and abutting the magnet close to each other, thereby better fixing the magnet. Arranging multiple rotor punches without a protrusion between any two rotor punches with protrusions arranged in sequence can achieve the purpose of inserting the magnet into the magnet hole with fewer rotor punches with protrusions, thereby reducing the production cost of the rotor core.

[0105] The spacing between the two walls of each through hole in each rotor punch without protrusions is greater than the spacing between each protrusion on one wall and the other wall of a through hole in a rotor punch with protrusions. On one hand, the rotor core of the motor comprises multiple rotor punches without protrusions and multiple rotor punches with protrusions. This eliminates the need to machine multiple protrusions spaced along the second direction on the walls of the through holes in each rotor punch, thereby preventing direct contact between the magnets and the walls and reducing the production cost of the rotor core. On the other hand, because the spacing between the two walls of each through hole in each rotor punch without protrusions is greater than the spacing between each protrusion on one wall and the other wall of a through hole in a rotor punch with protrusions, multiple gaps can be formed between each wall of each through hole in each rotor punch and the magnets.

[0106] In some embodiments, the number of non-protrusion rotor punchings between any two sequentially spaced protrusion rotor punchings is equal. As shown in FIG9 , along the axial direction of the motor 30, the number of non-protrusion rotor punchings 321e between any two sequentially spaced protrusion rotor punchings 321c is six. In this way, the distance between the two positions where any two sequentially spaced protrusions corresponding to a magnet hole abut the magnet along the axial direction of the motor 30 is fixed, and the protrusion corresponding to a magnet hole can stably insert the magnet into the magnet hole.

[0107] In some embodiments, the rotor punching at the end of the rotor core is another rotor punching without protrusions, and the number of rotor punchings without protrusions between the other rotor punching without protrusions and one of the two rotor punchings without protrusions is less than or equal to the number of rotor punchings without protrusions between any two rotor punchings with protrusions arranged in sequence. As shown in Figures 9 to 11, there are two rotor punchings without protrusions 321e between the rotor punching without protrusions 321e at the end of the rotor core and the first rotor punching with protrusions 321c, and six rotor punchings without protrusions 321e between the two rotor punchings with protrusions 321c. As shown in Figure 10, there are two rotor punchings without protrusions 321e between the rotor punching without protrusions 321e at the end of the rotor core and the first rotor punching with protrusions 321c, and three or four rotor punchings without protrusions 321e between the two rotor punchings with protrusions 321c. In this way, the magnets can be inserted into the magnet holes by using fewer rotor punching sheets with protrusions, thereby reducing the production cost of the rotor core.

[0108] In one embodiment, the distance between the other protrusion-free rotor punching and the protrusion-bearing rotor punching adjacent to one of the two protrusion-free rotor punchings is greater than or equal to 0.2 mm. In this way, the flatness of the end surface of the rotor core can be ensured.

[0109] In some embodiments, the number of rotor punches without projections between two rotor punches without projections is greater than the number of rotor punches with projections between two rotor punches without projections. Accordingly, with fewer rotor punches with projections, it is possible to insert the magnets into the through-holes of the rotor punches without contact with the walls of the through-holes, thereby reducing the production cost of the rotor core.

[0110] In some embodiments, the two protrusions of a magnet hole are spaced apart along the first direction, and the two protrusions are located on different protrusion-bearing rotor punchings. There is a gap between the hole wall where one protrusion is located and the hole wall where the other protrusion is located. In this way, the magnet can be inserted into the magnet hole along the gap. For example, as shown in FIG10 , the left hole wall T of a protrusion-bearing rotor punching 321a is a2 The protrusion on the right hole wall T of another rotor punching piece 321b with a protrusion a1 The protrusions on the rotor punch are arranged at intervals along the first direction. Accordingly, a protrusion is machined on one hole wall of the through hole of the rotor punching, and two identical rotor punchings with the protrusion are laminated back to back, so that the protrusion-bearing hole walls of the rotor punching with the protrusion are different hole walls of the through hole of the rotor punching with the protrusion arranged along the first direction. In this way, both hole walls of each magnet hole along the first direction include protrusions, simplifying the machining process and production cost of the rotor punching.

[0111] In one embodiment, two rotor punchings with protrusions are arranged adjacent to each other along the axial direction of the motor 30. In this way, the positions of the two protrusions arranged continuously and spaced apart along the axial direction of the motor 30 against the magnet are close to each other, which can better fix the magnet.

[0112] In some embodiments, the number of rotor punchings with protrusions is less than the number of rotor punchings without protrusions. In this way, the magnets can be inserted into the magnet holes with fewer rotor punchings with protrusions, reducing the production cost of the rotor core.

[0113] In some embodiments, each protrusion has similar dimensions along the first direction, and each protrusion has similar dimensions along the second direction. This allows each magnet to be inserted into the middle of a magnet hole along the first direction. This allows the injection molding compound to have a relatively uniform flow resistance within the magnet hole, resulting in a more stable injection molding process. Furthermore, the rotor 320 of the motor 30 has a smaller dynamic imbalance, thereby reducing the time and cost of dynamic balancing.

[0114] In some embodiments, the projections of the two protrusions of the rotor punchings with protrusions overlap along the axial direction of the motor 30, that is, the protrusions of the two rotor punchings with protrusions are aligned along the axial direction of the motor 30. In this way, the two protrusions of the two rotor punchings with protrusions, which are respectively aligned along the axial direction of the motor 30, and the abutting positions are almost in a straight line along the axial direction of the motor 30. Furthermore, the two protrusions aligned along the axial direction of the motor 30 can clamp the magnet to prevent the magnet from tilting or offsetting along the axial direction of the motor 30.

[0115] In some embodiments, as shown in Figures 9 to 11, the size of each magnet along the first direction is greater than the distance between two protrusions of a magnet hole that are spaced apart along the first direction. That is, the distance between each magnet and the two protrusions spaced apart along the first direction is an interference fit. In this way, when the magnet is inserted into the magnet hole along the axial direction of the motor 30, each protrusion can be elastically deformed along the direction in which the magnet is inserted into the magnet hole, providing elastic restoring force to the magnet through the two side surfaces of the magnet and abutting the magnet, so that the magnet will not tilt or deflect in the magnet hole. Moreover, the probability of the magnet falling off from the magnet hole is reduced, which facilitates the transportation of the rotor 320 of the motor 30.

[0116] In some embodiments, along the first direction, the difference between the size of the magnet and the interval between the two protrusions is less than or equal to 0.1 mm, thereby reducing the wear of the insulating layers on the two side surfaces of the magnet by the protrusions.

[0117] In some embodiments, the projection of each protrusion corresponding to a magnet hole along the second direction is arranged between the projections of the other two side surfaces of each magnet arranged oppositely along the second direction. For example, as shown in Figures 9 to 11, along the second direction, the magnet holes formed by the plurality of through holes 3211a of the plurality of rotor punchings connected along the axial direction of the motor 30 are arranged on the upper side surfaces W of the magnets 322a arranged oppositely along the second direction. a3 The projection and lower side W a4 Thus, each protrusion is used to clamp the magnet, thus avoiding unnecessary protrusions being processed on the hole wall of the through hole of the rotor punching sheet, thereby reducing the production cost of the motor 30.

[0118] In some embodiments, the distance between a protrusion corresponding to a magnet hole and one of the other two side surfaces is greater than or equal to R, where R is the radius of the chamfer between one of the other two side surfaces of the magnet and the side surface of the two adjacent side surfaces. Along the second direction, a protrusion is arranged adjacent to one of the other two side surfaces. This allows the protrusion to better connect the magnet to the magnet hole. For example, R is 1 mm.

[0119] In some embodiments, as shown in Figures 9 to 11, after the magnet is inserted into the through-hole of the rotor punching along the axial direction of the motor, the multiple protrusions of the multiple protrusions of the rotor punching with protrusions bend along the axial direction of the motor. During the process of inserting the magnet into the through-hole of the rotor punching along the axial direction of the motor, each protrusion can be elastically deformed along the axial direction of the motor along the direction of the magnet's insertion into the through-hole of the rotor punching, providing an elastic restoring force to the magnet and abutting the magnet, so that the magnet is inserted into the through-hole of the rotor punching.

[0120] Structure ②: The hole wall of the through hole with the protruding rotor punch includes a groove

[0121] Each groove includes a bottom and a notch, arranged opposite each other along a first direction. Along the second direction, the notch is larger than the bottom. As shown in Figure 13, each groove G includes a bottom G1 and a notch G2, arranged along the first direction. Along the second direction, the notch G2 is larger than the bottom G1. The notch G2 of each groove G faces away from the magnet. This creates a trapezoidal cross-section, making it easier for the injection molding compound to flow into the groove G along its slope.

[0122] In some embodiments, the dimension of each groove in a hole wall along the first direction is smaller than the dimension along the second direction. Accordingly, after injecting plastic into the through hole of the rotor punching, the contact area between the plastic and the magnet can be increased, so that the magnet can be firmly inserted into the through hole of the rotor punching.

[0123] In one embodiment, only one of the two hole walls of each through hole of the rotor punching with a protrusion includes a plurality of grooves, thereby reducing the production cost of the rotor punching.

[0124] In another embodiment, the two hole walls of each through hole of the protruding rotor punching include multiple grooves, and in the two hole walls: the multiple grooves of one hole wall and the multiple grooves of the other hole wall are respectively arranged relatively spaced apart along the first direction, and the spacing between the two grooves of the two hole walls arranged relatively spaced apart along the first direction is greater than the size of a magnet along the first direction.

[0125] Because the multiple grooves of one hole wall and the multiple grooves of the other hole wall are arranged relative to each other along the first direction, when the injection molding compound is injected into the through-hole of the rotor punching of the motor, the flow resistance between each hole wall and the side surface of the adjacent magnet is relatively even, making the injection molding process more stable. In addition, because the spacing between the two grooves of the two hole walls arranged relative to each other along the first direction is greater than the size of a magnet along the first direction, there is a gap between each hole wall and the side surface of the adjacent magnet. In this way, when the injection molding compound is injected into the through-hole of the rotor punching of the motor, it is possible to avoid direct contact between one of the two hole walls and the side surface of the adjacent magnet due to the influence of gravity.

[0126] In one example, the number of grooves in the two hole walls is equal. In this way, when the plastic injection glue is injected into the through hole of the rotor punching of the motor, the amount of plastic injection glue entering between each hole wall and the side of the adjacent magnet is relatively even, so that the dynamic imbalance of the motor rotor is small, thereby reducing the cycle and cost of dynamic balance correction. In addition, the projection of each groove of one hole wall of the two hole walls along the first direction overlaps with the projection of a groove of the other hole wall along the first direction. In other words, along the first direction, each groove of one hole wall of the two hole walls is aligned with a groove of the other hole wall. As shown in Figures 12 and 13, the right hole wall T of the two hole walls of each through hole of the rotor punching with a protrusion a1 Each groove G and the left hole wall T a2 Thus, the right side W of the magnet 322a flows into the magnet 322a. a1 The right wall T of the through hole 3211a a1 The plastic injection between the left side W a2 The left wall T of the through hole 3211a a2 The amount of plastic injection inside is relatively balanced, which prevents the magnet from tilting or deflecting along the first direction.

[0127] In another example, the number of grooves in the two hole walls is different. For example, along the direction of gravity, the number of grooves in the lower hole wall of a through hole is greater than the number of grooves in the upper hole wall of a through hole. This prevents the magnet from directly contacting the lower hole wall of a through hole due to the influence of gravity. In this way, after injecting plastic into the magnet hole, it can avoid the influence of gravity causing the grooves in the lower hole wall of a through hole to be too low.

[0128] In some embodiments, at least one hole wall of each of two circumferentially adjacent through-hole groups includes multiple grooves. As shown in FIG13 , each through-hole group 3211 includes four through-holes, and each hole wall of each through-hole in each through-hole group 3211 includes multiple grooves G. The four through-holes in the other through-hole group do not include any grooves. This allows lamination of multiple identical rotor punches with protrusions to form the rotor core simply by connecting each through-hole of two adjacent identical rotor punches with protrusions axially along the circumference of the rotor punches, thereby simplifying the assembly process of the rotor punches with protrusions.

[0129] In other embodiments, at least one hole wall of one of two adjacent through-hole groups along the circumference of the motor includes multiple grooves, while each hole wall of the other through-hole group does not include grooves. As shown in FIG14 , each through-hole group 3211 includes four through-holes, and each hole wall of the four through-holes in one of the two adjacent through-hole groups 3211 includes multiple grooves G, while each hole wall of the four through-holes in the other through-hole group does not include grooves. As shown in FIG15 , each through-hole group includes twelve through-holes, and each hole wall of the twelve through-holes in one of the two adjacent through-hole groups 3211 includes multiple grooves, while each hole wall of the twelve through-holes in the other through-hole group does not include grooves. In this way, in the process of stacking multiple identical rotor punchings with protrusions to form a rotor core, it is only necessary to rotate one of the two adjacent rotor punchings with protrusions by a certain angle along the circumferential direction of the rotor punchings with protrusions, so that one of the two adjacent through-hole groups of one rotor punching with protrusions is connected to the other of the two adjacent through-hole groups of another adjacent rotor punching with protrusions along the axial direction of the rotor core, so that each magnet hole can include a protrusion, which simplifies the processing technology and production cost of the rotor punchings with protrusions.

[0130] In some embodiments, the number of rotor punchings with protrusions is less than the number of rotor punchings without protrusions. Accordingly, with fewer rotor punchings with protrusions, it is possible to insert the magnets into the through-holes of the rotor punchings without contact with the walls of the through-holes, thereby reducing the production cost of the rotor core.

[0131] In some embodiments, each groove has similar dimensions along the first direction, and each groove has similar dimensions along the second direction. This improves the flow resistance of the plastic into the magnet holes, making the injection molding process more stable. Furthermore, the dynamic imbalance of the rotor 320 of the motor 30 is minimized, thereby reducing the time and cost of dynamic balancing corrections.

[0132] In some embodiments, the projections of the grooves of the two protruding rotor punchings overlap along the axial direction of the motor 30, that is, the two grooves of the two protruding rotor punchings are aligned along the axial direction of the motor 30, and the two grooves of the two protruding rotor punchings, each aligned along the axial direction of the motor 30, are almost located in a straight line along the axial direction of the motor 30. As a result, the injection molding glue can flow along the axial direction of the motor 30, thereby preventing the magnet from tilting or offsetting along the axial direction of the motor 30.

[0133] In an embodiment where the rotor core's multiple rotor laminations 321 include multiple protruding rotor laminations and multiple non-protruding rotor laminations, in one example, multiple protruding rotor laminations are arranged between two non-protruding rotor laminations along the axial direction of the motor 30. This reduces the production cost of the rotor core. In another example, multiple non-protruding rotor laminations are arranged between two protruding rotor laminations along the axial direction of the motor 30. This allows the injection molding compound to flow more easily into the magnet holes.

[0134] In an embodiment where the rotor core's multiple rotor punchings 321 include multiple rotor punchings with protrusions and multiple rotor punchings without protrusions, the distance between the two hole walls of each through hole in each rotor punching without protrusions is smaller than the distance between each groove in one hole wall and the other hole wall of a through hole in a rotor punching with protrusions. On the one hand, the rotor core of the motor includes multiple rotor punchings without protrusions and multiple rotor punchings with protrusions. This eliminates the need to punch a through hole with multiple grooves spaced along the second direction in each rotor punching, thereby avoiding direct contact between the magnet and the hole wall and reducing the production cost of the rotor core. On the other hand, because the distance between the two hole walls of each through hole in each rotor punching without protrusions is smaller than the distance between each groove in one hole wall and the other hole wall of a through hole in a rotor punching with protrusions, each hole wall of each through hole in each rotor punching can form multiple gaps with the magnet.

[0135] Structure ③: The side of the magnet includes grooves

[0136] In one embodiment, one of the two side surfaces of each magnet includes a plurality of grooves. Thus, when the magnet is inserted into the magnet hole with the grooved side facing downward in the direction of gravity, and plastic injection is injected into the magnet hole, the effect of gravity can be avoided, which can prevent the plastic injection from being too little between the grooved side of the magnet and the wall of the through hole.

[0137] In another embodiment, each of the two side surfaces of each magnet includes a plurality of grooves. As shown in FIG16 to FIG19 , the right side surface W of each magnet a1 and left side W a2Each includes a plurality of grooves G spaced apart along the second direction. This prevents uneven plasticizing between each of the two side surfaces of the magnet and the adjacent hole walls due to the influence of gravity after the injection molding compound is injected into the magnet hole. This allows the magnet to directly contact the rotor punching 321, reducing the short circuit between the mutually insulated protruding rotor punchings through the magnet, thereby reducing eddy current losses in the rotor core. Furthermore, the plurality of grooves G spaced apart along the second direction allows the magnet to be secured in the magnet hole with less plasticizing compound, thereby reducing the production cost of the rotor of the motor 30.

[0138] In one example, the number of grooves on both sides of a magnet is equal, and the grooves on one side are arranged opposite the grooves on the other side along a first direction. Accordingly, when the plastic is injected into the through-holes of the motor rotor punchings, the amount of plastic entering each hole wall and the adjacent magnet side is relatively even, reducing the dynamic imbalance of the motor rotor and the time and cost of dynamic balancing corrections.

[0139] In addition, the projection of each groove of one of the two side surfaces of a magnet along the first direction overlaps with the projection of a groove of the other side surface along the first direction. In other words, along the first direction, each groove of one of the two side surfaces of a magnet is aligned with a groove of the other side surface. As shown in FIG17 , the right side surface W of the magnet 322 a is a1 Each groove G and the left side W a2 Thus, as shown in FIG20 , the right side W of the inflow magnet 322 a is aligned. a1 The right wall T of the through hole 3211a a1 The plastic injection between the left side W a2 The left wall T of the through hole 3211a a2 The amount of plastic injection inside is relatively balanced, which prevents the magnet from tilting or deflecting along the first direction.

[0140] In another example, a magnet has different numbers of grooves on its two sides. In this case, the magnet can be inserted into the magnet hole, oriented in the direction of gravity, with the side with more grooves facing downward and the side with fewer grooves facing upward. After injecting the plastic into the magnet hole, this prevents the effect of gravity from causing insufficient plastic between the side with more grooves and the wall of the through-hole.

[0141] In some embodiments, as shown in FIG17 , each groove G of each magnet includes a groove bottom G1 and a groove opening G2 aligned along a first direction. Along a second direction, the groove opening G2 is larger than the groove bottom G1. The groove opening G2 of each groove G faces away from the magnet. This creates a trapezoidal cross-section, making it easier for the injection molding compound to flow into the groove G along its slope.

[0142] In some embodiments, the dimensions of each groove G of each magnet along the first direction are similar. This allows each magnet to be inserted into the middle of a magnet hole along the first direction. This allows the flow resistance of the plastic injection molding compound into the magnet hole to be relatively uniform, resulting in a more stable injection molding process. Furthermore, the dynamic imbalance of the rotor 320 of the motor 30 is minimized, thereby reducing the time and cost of dynamic balancing corrections.

[0143] If structures ① and ② are combined, in some embodiments, the number of protrusions on one wall of a through hole in a rotor punch with protrusions is the same as the number of grooves on the other wall. This allows the injection molding compound to enter the through hole of the motor rotor punch with a relatively even amount of plastic between each wall and the side of the adjacent magnet, minimizing the dynamic imbalance of the motor rotor and reducing the frequency and cost of dynamic balancing.

[0144] If structures ① and ③ are designed in combination, in some embodiments, the number of protrusions on a hole wall of a through hole in a rotor punching with a protrusion is the same as the number of grooves on the other side of the two side surfaces of a magnet accommodated by the through hole. Here, one of the two hole walls of a through hole, one of the two side surfaces of a magnet accommodated by the through hole, the other side surface of the two side surfaces of a magnet accommodated by the through hole, and the other hole wall of the two hole walls of a through hole are arranged sequentially along a first direction. In this way, when the plastic injection glue is injected into the through hole of the rotor punching of the motor, the amount of plastic injection glue that enters each hole wall and the side surface of the adjacent magnet is relatively even, resulting in a smaller dynamic imbalance of the motor rotor, thereby reducing the cycle time and cost of dynamic balancing correction.

[0145] If structures ② and ③ are combined, in some embodiments, the number of grooves in one wall of a through hole in a rotor punch with a protrusion is the same as the number of grooves in the other of the two side surfaces of a magnet accommodated in the through hole. This allows the plastic injection into the through hole of the motor rotor punch to penetrate relatively evenly between each wall and the adjacent side surface of the magnet, minimizing the dynamic imbalance of the motor rotor and reducing the frequency and cost of dynamic balancing corrections.

[0146] Typically, the rotor punching 321 is a silicon steel sheet, that is, the rotor punching 321 is made of silicon steel. The magnet can also be called magnetic steel, and the magnet hole can also be called magnetic steel slot.

[0147] In some embodiments, in order to effectively isolate the high-frequency noise and harmonics in the stator winding of the motor 30 and improve the stability and anti-interference ability of the motor 30, as shown in Figures 2 to 5, 12, 13, 16, 18 and 19, the upper side surface W of the magnet 322a along the second direction is a3 With the upper hole wall Ta3 There is a gap H1 between the lower side W of the magnet 322a along the second direction. a4 With the lower hole wall T a4 There is another gap H2 between the two gaps. The gap H1 and the gap H2 are both used to fill magnetic isolation materials.

[0148] In one embodiment, in order to prevent the magnet from moving in the second direction, at least one hole wall of each through hole further includes two limiting protrusions. In the second direction, the magnet is located between the two limiting protrusions, and the projections of the two limiting protrusions and the projection of the magnet in the first direction overlap. For example, as shown in Figures 3 to 6, 8, 12 to 14, 18 and 19, the left hole wall T of the two hole walls of each through hole of the rotor punching is a2 The invention comprises two limiting protrusions, namely a limiting protrusion Q11 and a limiting protrusion Q12. In another embodiment, at least one hole wall of each through hole further comprises a limiting protrusion and a limiting groove, and the magnet is located between the two limiting protrusions along the second direction, and the projections of the two limiting protrusions and the projection of the magnet along the first direction overlap. For example, as shown in FIG3 , the left hole wall T of the two hole walls of each through hole with a protrusion rotor punching 321a is a2 It includes two limiting protrusions, which are a limiting protrusion Q11 and another limiting protrusion Q12.

[0149] In some embodiments, the motor 30 further includes a stator, and the stator includes a stator core and a stator winding. The stator core is sleeved outside the rotor, and the stator winding is wound around the stator core.

[0150] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A rotor punching with a protrusion, characterized in that: The rotor punching sheet with protrusions comprises a central hole and a plurality of through holes, wherein the plurality of through holes are arranged around the central hole, wherein the size of each through hole along a first direction is smaller than the size along a second direction, and each through hole comprises two hole walls arranged opposite to each other along the first direction, and one hole wall of a through hole comprises: A plurality of protrusions, wherein the plurality of protrusions are arranged at intervals along the second direction, and the length of each of the protrusions along the first direction is smaller than the distance between the two hole walls; or, A plurality of grooves are arranged at intervals along the second direction, each of the grooves comprises a groove bottom and a groove opening which are arranged opposite to each other along the first direction, and a size of the groove opening along the second direction is larger than a size of the groove bottom.

2. The rotor punching sheet with protrusions according to claim 1, characterized in that: The numbers of the protrusions of the two hole walls are the same, or the numbers of the grooves of the two hole walls are the same, or the number of the protrusions of one hole wall is the same as the number of the grooves of the other hole wall.

3. The rotor punching sheet with protrusions according to claim 1, characterized in that: A dimension of each protrusion along the first direction is greater than a dimension of each protrusion along the second direction.

4. The rotor punching sheet with protrusions according to claim 1, characterized in that: The depth of each of the grooves in the one hole wall along the first direction is smaller than the width along the second direction.

5. The rotor punch with projections according to any one of claims 1 to 4, characterized in that: The plurality of through holes include a plurality of through hole groups, and the number of the plurality of through holes is a multiple of the number of the plurality of through hole groups, wherein: The plurality of through hole groups are arranged around the central hole, and at least one of two through hole groups adjacent to each other along the circumference of the motor includes the one through hole.

6. A motor rotor, characterized in that: The rotor core of the motor rotor comprises a plurality of rotor punches without protrusions and a plurality of rotor punches with protrusions as described in any one of claims 1 to 5, each of the rotor punches without protrusions comprises a plurality of through holes, each of the through holes of each of the rotor punches without protrusions comprises two hole walls arranged oppositely along the first direction, and the size of each through hole of the rotor punches without protrusions along the first direction is smaller than the size along the second direction, wherein: The distance between the two hole walls of each through hole in each of the protrusion-free rotor punching sheets is greater than the distance between each protrusion of one hole wall and another hole wall in the through hole of one of the protrusion-bearing rotor punching sheets; or, The distance between the two hole walls of each through hole in each of the rotor punches without protrusions is smaller than the distance between each groove of one hole wall and another hole wall in one of the through holes of one of the rotor punches with protrusions.

7. The motor rotor according to claim 6, characterized in that: The plurality of rotor punching sheets with protrusions are arranged between two rotor punching sheets without protrusions along the axial direction of the motor.

8. The motor rotor according to claim 7, characterized in that: Another one or more of the rotor punches without protrusions are arranged between two of the rotor punches with protrusions.

9. The motor rotor according to claim 8, characterized in that: The number of the plurality of protrusion-free rotor punches between the two protrusion-free rotor punches is greater than the number of the plurality of protrusion-equipped rotor punches between the two protrusion-free rotor punches.

10. The motor rotor according to any one of claims 6 to 9, characterized in that: The number of the plurality of rotor punches with protrusions is less than the number of the plurality of rotor punches without protrusions.

11. A motor, characterized in that: The motor comprises a motor rotor as described in any one of claims 6 to 10 and a plurality of magnets, each of the magnets comprising two side surfaces arranged opposite to each other along the first direction, a hole wall of a through hole of a protruding rotor punching sheet and a side surface of a magnet accommodated in the through hole being arranged adjacent to each other along the first direction, and a plurality of gaps arranged at intervals along the second direction are present between the hole wall and the side surface.

12. The motor according to claim 11, characterized in that The length of each of the protrusions along the first direction is smaller than the size of the one magnet along the first direction and larger than the size of each of the gaps along the first direction; The plurality of protrusions of the plurality of rotor punching sheets with protrusions are bent along the axial direction of the motor.

13. The motor according to claim 11, characterized in that The two hole walls of the through hole of the rotor punching sheet with protrusions respectively include a plurality of protrusions, and in the two hole walls: The multiple protrusions of one hole wall and the multiple protrusions of the other hole wall are arranged opposite to each other along the first direction, and the interval between the two protrusions of the two adjacent hole walls along the first direction is smaller than the size of the one magnet along the first direction.

14. The motor according to claim 11, characterized in that The two hole walls of the through hole of the rotor punching sheet with a protrusion respectively include a plurality of the grooves, and in the two hole walls: The multiple grooves of one hole wall and the multiple grooves of the other hole wall are arranged relatively spaced apart along the first direction, and the distance between the two grooves of the two hole walls relatively spaced apart along the first direction is greater than the size of the one magnet along the first direction.

15. A powertrain, characterized in that: The power assembly includes a reducer and a motor as claimed in any one of claims 11 to 14, wherein the motor further includes a motor shaft, the rotor core is sleeved on the motor shaft, and the motor shaft is drivingly connected to an input shaft of the reducer.

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