Cooling structure of motor rotor, motor and vehicle

Abstract

The application provides a cooling structure of a motor rotor, a motor and a vehicle, and belongs to the technical field of automobiles. The cooling structure comprises a rotating shaft, a magnetic steel seat, a rotor assembly and a stator assembly. The rotating shaft is a hollow shaft with a shaft center hole. The magnetic steel seat is embedded in one end of the rotating shaft, and the magnetic steel seat has a communication channel communicating with the shaft center hole. The rotor assembly is installed on the rotating shaft and rotates synchronously with the rotating shaft. The stator assembly is sleeved outside the rotor assembly and has a first axial gap between the end of the rotor assembly and the stator assembly in the axial direction and a first radial gap between the circumferential surface of the rotor assembly and the stator assembly in the radial direction. The cooling medium enters the shaft center hole from one end of the rotating shaft, enters the first axial gap and the first radial gap through the communication channel, and the outflow side and the inflow side of the cooling medium are on the same side of the rotor assembly, thereby forming a cooling channel of the motor rotor and greatly improving the cooling and heat dissipation effect of the rotor.

Description

Technical Field

[0001] This application belongs to the field of automotive technology, and more specifically, relates to a cooling structure for an electric motor rotor, an electric motor, and a vehicle. Background Technology

[0002] Existing permanent magnet synchronous motors generally use holes on the shaft for bearing spray cooling. This spraying method can easily create a dead zone in the oil cavity at the bearing, making it difficult for cooling oil to enter the bearing, affecting the heat dissipation of the bearing and rotor, and thus affecting the performance of the motor. Utility Model Content

[0003] The purpose of this application is to provide a cooling structure for an electric motor rotor, an electric motor, and a vehicle, in order to solve the problem of poor cooling effect of the electric motor rotor.

[0004] To achieve the above objectives, firstly, the technical solution adopted in this application is: to provide a cooling structure for an electric motor rotor, comprising:

[0005] The shaft is a hollow shaft with a central hole.

[0006] A magnet base is embedded in one end of the rotating shaft, and the magnet base has a communicating channel that connects to the central hole of the shaft;

[0007] The rotor assembly is mounted on the rotating shaft and rotates synchronously with the rotating shaft;

[0008] A stator assembly is fitted over the rotor assembly and has a first axial clearance between itself and the end of the rotor assembly in the axial direction, and a first radial clearance between itself and the circumferential surface of the rotor assembly in the radial direction.

[0009] The cooling medium enters the central hole of the shaft from one end of the shaft, passes through the connecting channel, and then enters the first axial gap and the first radial gap. The outflow side and the inflow side of the cooling medium are on the same side of the rotor assembly, forming a cooling channel for the motor rotor and the bearing.

[0010] The cooling structure of the motor rotor shown in this application embodiment, compared with the prior art, has a magnet seat with magnets embedded in the end of the rotating shaft, and a connecting channel is provided on the magnet seat to connect the shaft center hole of the rotating shaft, so that the cooling medium entering the shaft center hole from one end flows to the other end of the rotating shaft, and after flowing out from the connecting channel, it enters the first radial gap along the first axial gap between the stator assembly and the rotor assembly. The outflow side and the inflow side of the cooling medium are on the same side of the rotor assembly, forming a circulating and unobstructed cooling channel, realizing effective cooling of the entire rotor assembly, thereby greatly improving the cooling effect of the rotor.

[0011] For permanent magnet synchronous motors, this application fixes the magnet to one end of the shaft using a method where the magnet seat is embedded within the shaft. This installation method does not increase the axial length of the shaft or change its original length, thus avoiding interference with the Hall effect plate encapsulating the bearing. Therefore, embedding the magnet seat within the shaft does not increase the overall dimensions of the rotor assembly or alter its shape. Simultaneously, the magnet seat also participates in rotor cooling as part of the cooling channel. The cooling medium passes through the center of the rotor assembly, then through the magnet seat, changes its flow direction, and re-enters the rotor assembly. Therefore, the magnet seat, while fulfilling its primary function, also constitutes part of the cooling channel and serves multiple purposes by altering the flow direction of the cooling medium. However, the magnet seat does not increase the overall dimensions of the rotor assembly, optimizes the motor structure, and saves internal space.

[0012] In conjunction with the first aspect, in one possible implementation, the magnet seat partially has an interference fit with the rotating shaft, and partially has a clearance fit with the rotating shaft to form a second radial clearance; the interference fit portion of the magnet seat has a seat center hole that connects to the shaft center hole, and the magnet seat is provided with a connecting hole that connects the seat center hole and the second radial clearance; the seat center hole, the connecting hole, and the second radial clearance constitute the connecting channel.

[0013] In the above technical solution, the magnet seat is embedded in the rotating shaft, which not only has the function of sensing the rotational speed of the rotating shaft, but also has the function of a cooling channel. Moreover, the installation method of embedding the magnet seat does not increase the axial length of the rotating shaft, thus optimizing the cooling structure of the rotor assembly and also optimizing the axial space of the rotor assembly.

[0014] The magnet seat is interference-fitted onto the rotating shaft. This serves two purposes: firstly, to maintain synchronous rotation with the shaft, and secondly, to guide the flow of the cooling medium. The cooling medium passes through the center hole of the seat and enters the connecting hole, then enters the second radial clearance reserved during clearance fitting, forming part of the cooling channel.

[0015] In conjunction with the first aspect, in one possible implementation, there is a second axial gap between the bearing at the end of the shaft and the Hall plate sealing the bearing; the second axial gap communicates with the second radial gap.

[0016] In the above technical solution, there is a gap between the rotating shaft and the magnet seat and the Hall plate in the axial direction. This gap is necessary to ensure the rotation of the rotating shaft. Therefore, the second axial gap between the rotating shaft and the Hall plate also constitutes part of the cooling channel. After the cooling medium flows to the second axial gap, it contacts and cools the bearing at this point. Since there is a partial cooling channel on the other side of the bearing, the smooth flow of the cooling medium is ensured, thus avoiding the risk of the cooling medium forming a dead zone in the oil cavity here. The bearing can be cooled by the flowing cooling medium at all times, thereby improving the cooling effect of the bearing.

[0017] In conjunction with the first aspect, in one possible implementation, the magnet base includes a magnet fixing base and an induction magnet embedded in the magnet fixing base, wherein the induction magnet and the Hall plate have a third axial gap, the third axial gap communicating with the second axial gap; the center hole of the base, the connecting hole and the second radial gap are disposed on the magnet fixing base.

[0018] In the above technical solution, the induction magnet is mounted on the end of the rotating shaft via a magnet mounting bracket. This not only provides the inherent characteristic of sensing the shaft's rotational speed but also offers a channel for the cooling medium, allowing it to flow from the oil pump end through the shaft's central hole to the bearing mounting end for fluid cooling. This structural design not only reduces the number of parts but also avoids compromising the integrity of core components such as the stator and rotor assemblies. Furthermore, it maintains or facilitates a reduction in the motor's overall dimensions, thus optimizing the motor's structure.

[0019] In conjunction with the first aspect, in one possible implementation, the magnet fixing seat has an interference fit section that is interference-fitted into the rotating shaft and a clearance fit section that is clearance-fitted into the rotating shaft. The connecting hole is disposed in the clearance fit section, and the clearance between the clearance fit section and the rotating shaft constitutes the second radial clearance. The seat center hole is disposed in the interference fit section. The diameter of the clearance fit section is larger than that of the interference fit section, constituting an axial limiting surface. An axial stop surface that can abut against the axial limiting surface is disposed inside the rotating shaft to limit the axial embedding depth of the magnet fixing seat.

[0020] In the above technical solution, a simple change to the structure of the magnet fixing seat can achieve synchronous rotation with the rotating shaft after installation, and can also directly form a second radial gap between the rotating shaft and the magnet fixing seat, forming part of the cooling channel. While considering the cooling medium passage through the magnet fixing seat, the overall structure of the motor is also optimized, thus achieving the purpose of optimizing the motor structure.

[0021] In conjunction with the first aspect, in one possible implementation, the magnet base is provided with a plurality of the connecting holes along the circumferential direction.

[0022] In the above technical solution, multiple connecting holes are uniformly arranged along the circumference, and the multiple connecting holes connect to the second radial gap of the ring to ensure the smooth flow of the cooling medium.

[0023] In conjunction with the first aspect, in one possible implementation, the diameter of the shaft center hole is greater than the diameter of the seat center hole, the diameter of the seat center hole is greater than the diameter of the connecting hole, and the diameter of the connecting hole is greater than the radial width of the second radial gap.

[0024] In the above technical solution, the diameter or width of the cooling channel gradually decreases from the oil inlet end of the cooling medium towards the direction away from the oil inlet end, which can increase the flow rate of the cooling medium. The high-speed flowing oil can carry away heat more efficiently and avoid local overheating.

[0025] In conjunction with the first aspect, in one possible implementation, the axial width of the first axial gap is greater than the radial width of the first radial gap.

[0026] In the above technical solution, the aperture or width of the cooling channel gradually decreases from the direction of the cooling medium return flow, which can increase the flow rate of the cooling medium. The high-speed flowing oil can carry away heat more efficiently and avoid local overheating.

[0027] Secondly, embodiments of this application also provide an electric motor, including the cooling structure for the motor rotor.

[0028] This design, in which the magnet seat for sensing the rotational speed of the shaft is embedded inside the shaft and also forms part of the cooling channel, does not increase the axial length of the shaft or change its original length. While optimizing the cooling channel and improving the cooling and heat dissipation effect of the rotor and bearings, it also optimizes the overall structure of the motor, saves internal space, and improves the performance of the motor.

[0029] Thirdly, embodiments of this application also provide a vehicle including the aforementioned motor.

[0030] The vehicle provided in this application improves its performance by using a motor with good cooling and optimized structure. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1A cross-sectional view of the motor provided in an embodiment of this application;

[0033] Figure 2 This is a schematic diagram of the cooling oil circuit of the motor provided in an embodiment of this application;

[0034] Figure 3 This is a cross-sectional view of the magnet holder provided in an embodiment of this application;

[0035] Figure 4 for Figure 3 A side view of the magnet holder shown.

[0036] Figure 5 for Figure 1 A magnified schematic diagram of the local structure at point A;

[0037] In the diagram: 1. Housing; 2. Stator assembly; 3. First axial clearance; 4. Rotor assembly; 5. First radial clearance; 6. Shaft; 7. Shaft center hole; 8. Oil inlet hole; 9. Seat center hole; 10. Induction magnet; 11. Magnet fixing seat; 12. Third axial clearance; 13. Connecting hole; 14. Second radial clearance; 15. Second axial clearance; 16. Bearing; 17. Hall effect partition. Detailed Implementation

[0038] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0039] It should be noted that when an element is referred to as being "set on" another element, it can be directly on or indirectly on that other element. It should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0040] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "a few" means two or more, unless otherwise explicitly specified.

[0041] In this application, axial refers to the direction of the axis of rotation of the shaft, radial refers to the direction of the diameter of the shaft, the axial clearance between two components is defined as the axial clearance, and the radial clearance between two components is defined as the radial clearance.

[0042] Please refer to the following: Figures 1 to 5 The cooling structure of the motor rotor provided in this application will now be described. The cooling structure of the motor rotor includes a rotating shaft 6, a magnet seat, a rotor assembly 4, and a stator assembly 2. The rotating shaft 6 is a hollow shaft with a central hole 7. The magnet seat is embedded in one end of the rotating shaft 6 and has a connecting channel that connects to the central hole 7. The induction magnet 10 embedded in the magnet seat is used to sense the rotational speed of the rotating shaft 6.

[0043] The rotor assembly 4 is mounted on the rotating shaft 6 and rotates synchronously with the rotating shaft 6; the stator assembly 2 is fitted outside the rotor assembly 4 and has a first axial gap 3 between the stator assembly 4 and the end of the rotor assembly 4 in the axial direction, and a first radial gap 5 between the stator assembly 2 and the circumferential surface of the rotor assembly 4 in the radial direction.

[0044] See Figure 2 As shown by the middle arrow, the cooling medium enters the central hole 7 of the shaft from one end of the rotating shaft 6, enters the first axial gap 3 and the first radial gap 5 through the connecting channel, and flows out from the same end of the rotating shaft 6, forming a cooling channel for the motor rotor and bearing 16.

[0045] Compared with the prior art, the cooling structure of the motor rotor provided in this application has a magnet seat with an induction magnet 10 embedded in the end of the rotating shaft 6, and a connecting channel is provided on the magnet seat to connect the shaft center hole 7 of the rotating shaft 6, so that the cooling medium entering the shaft center hole 7 from one end flows to the other end of the rotating shaft 6, and after flowing out from the connecting channel, it enters the first radial gap 5 along the first axial gap 3 between the stator assembly 2 and the rotor assembly 4, and flows back to the side where the cooling medium enters. The outflow side and the inflow side of the cooling medium are on the same side of the rotor assembly 4, forming a circulating and unobstructed cooling channel, realizing effective cooling of the entire rotor assembly 4, thereby greatly improving the cooling and heat dissipation effect of the rotor.

[0046] In this application, the shaft center hole 7 is inside the rotor assembly 4, forming an internal cooling channel for the rotor assembly 4. The first radial gap 5 extends along the circumferential surface of the rotor assembly 4, forming an external cooling channel for the rotor assembly 4. The first axial gap 3 wraps around the shaft end of the rotor assembly 4, and the first radial gap 5 wraps around the circumferential surface of the rotor assembly 4. The cooling medium enters from the shaft center hole 7 to axially cool the rotor assembly 4, and then flows out through the first axial gap 3 and along the first radial gap 5 to cool the rotor assembly 4. The shaft center hole 7 and the first radial gap 5 cooperate internally and externally to form a double U-shaped cooling channel, which greatly improves the cooling effect of the rotor assembly 4.

[0047] For permanent magnet synchronous motors, this application fixes the magnet to one end of the shaft 6 using a method where the magnet seat is embedded within the shaft 6. This installation of the magnet does not increase the axial length of the shaft 6, nor does it change the original length of the shaft 6. Therefore, it does not interfere with the Hall effect partition 17 encapsulating the bearing 16. Thus, embedding the magnet seat within one end of the shaft 6 does not increase the external dimensions of the rotor assembly 4, nor does it change the external shape of the rotor assembly 4. At the same time, the magnet seat also participates in the cooling of the rotor as part of the cooling channel. After passing through the center of the rotor assembly 4, the cooling medium changes its flow direction and re-enters the rotor assembly 4 after passing through the magnet seat. Therefore, while possessing its own functional properties, the magnet seat also constitutes part of the cooling channel and has multiple functions, including changing the flow direction of the cooling medium. However, the magnet seat does not increase the external dimensions of the stator assembly 2, optimizes the motor structure, and saves internal space in the motor.

[0048] Taking the suspension motor as an example, an oil pump is installed at one end of the shaft 6, which is also the oil inlet. The other end of the shaft 6 is supported by a bearing 16 installed in the housing 1, which is the bearing 16 mentioned in this application. The outer ring of the bearing 16 is tightly fitted with the inner hole of the housing 1, and the inner ring of the bearing 16 is installed on the shaft 6 and rotates with the shaft 6.

[0049] To explain, a suspension motor is a motor specifically designed for use in a vehicle's suspension system. It is typically combined with active or semi-active suspension technology to adjust the suspension's damping, stiffness, or height in real time, thereby improving the vehicle's handling, comfort, and adaptability. The term "suspension motor" does not refer to a specific type of motor structure, but rather to the motor that functionally serves the suspension system.

[0050] In this application, the stator assembly 2 includes a stator and a housing 1 enclosing the stator. The first axial clearance 3 is between the housing 1 and the rotor assembly 4, the first radial clearance 5 is between the stator and the rotor assembly 4, and the bearing 16 overlaps the rotor in the axial direction to ensure that the clearance of the bearing 16 is connected to the first axial clearance 3.

[0051] It should be noted that oil cooling is preferred as the cooling medium in this application.

[0052] In some embodiments, see Figure 1 As shown, the magnet seat part is interference-fitted with the rotating shaft 6, and the part is clearance-fitted with the rotating shaft 6 to form a second radial clearance 14; the interference-fitted part of the magnet seat has a seat center hole 9 that connects to the shaft center hole 7, and the magnet seat is provided with a connecting hole 13 that connects the seat center hole 9 and the second radial clearance 14; the seat center hole 9, the connecting hole 13 and the second radial clearance 14 form a connecting channel.

[0053] Combination Figure 2As indicated by the middle arrow, the cooling medium is pumped out from the oil pump, enters the shaft center hole 7 through the oil inlet hole 8 on the rotating shaft 6, flows along the shaft center hole 7 towards the magnet seat, passes through the seat center hole 9, the connecting hole 13 and the second radial clearance 14, and enters the gap between the end of the rotating shaft 6 and the Hall plate 17, where the bearing 16 is cooled. However, since the side of the bearing 16 facing the rotor assembly 4 has a first axial clearance 3 and a first radial clearance 5, forming a smooth channel, the cooling medium can be returned to the oil inlet end of the rotor assembly 4 after entering the bearing 16. It can then enter the first axial clearance 3 through the bearing 16, and then enter the first radial clearance 5, returning along the axial direction of the rotor assembly 4 to the oil inlet end of the rotor assembly 4, and flowing back into the oil pump, thus forming a cooling channel for the motor rotor and the bearing 16.

[0054] In the above technical solution, the magnet seat is embedded in the rotating shaft 6, which has the function of sensing the rotation speed of the rotating shaft 6 and also has the function of a cooling channel. Moreover, the installation method of embedding the magnet seat does not increase the axial length of the rotating shaft 6, thus optimizing the cooling structure of the rotor assembly 4 and also optimizing the axial space of the rotor assembly 4.

[0055] The magnet seat is interference-fitted onto the rotating shaft 6. This serves two purposes: firstly, to maintain synchronous rotation with the rotating shaft 6, and secondly, to guide the flow of the cooling medium. The cooling medium passes through the center hole 9 of the seat and enters the connecting hole 13, and then enters the second radial clearance 14 reserved during clearance fit.

[0056] Optionally, the magnet base and the rotating shaft 6 can be keyed together to maintain synchronous rotation with the rotating shaft 6. At the same time, when keyed together, a gap will be formed between the magnet base and the rotating shaft 6, through which the cooling medium can also enter the shaft end of the rotating shaft 6.

[0057] When the magnet seat is only radially connected to the rotating shaft 6 by the key, but there is no axial limit, a set screw can be installed between the magnet seat and the shaft end of the rotating shaft 6 to limit the axial movement of the magnet seat and prevent it from axially dislodging when the magnet seat rotates with the rotating shaft 6.

[0058] In some embodiments, see Figure 1 As shown, there is a second axial gap 15 between the bearing 16 at the end of the rotating shaft 6 and the Hall plate 17 of the sealed bearing 16; the second axial gap 15 is connected to the second radial gap 14.

[0059] The bearing 16 is installed at the end of the rotating shaft 6, which requires sealing the bearing 16. The Hall plate 17 of this application is limited to the end of the housing 1 by a retaining ring or screw through a hole. The axially extending stop inside the Hall plate 17 abuts against the outer ring of the bearing 16, thereby axially limiting the bearing 16.

[0060] In the above technical solution, there is a gap between the rotating shaft 6 and the magnet seat and the Hall plate 17 in the axial direction. This gap is necessary to ensure the rotation of the rotating shaft 6. Therefore, the second axial gap 15 between the rotating shaft 6 and the Hall plate 17 also constitutes part of the cooling channel. After the cooling medium flows to the second axial gap 15, it contacts and cools the bearing 16 at this point. Since the bearing 16 has a partial cooling channel on the other side, the smooth flow of the cooling medium is ensured, thus avoiding the risk of the cooling medium forming a dead zone in the oil cavity here. The bearing 16 can be cooled by the flowing cooling medium at all times, thereby improving the cooling effect of the bearing 16.

[0061] In this application, the natural gap between the Hall plate 17 and the rotating shaft 6 can form part of the cooling channel, and no additional structure is required. This does not increase the overall structural complexity of the motor or redundant components, thus optimizing the structure of the motor.

[0062] In this application, the inner and outer rings of bearing 16 are axially limited by a shaft retaining ring and a bore retaining ring, respectively, while the stop of the Hall plate 17 axially abuts against the bore retaining ring. The above describes the axial positioning of the outer side of bearing 16. For the inner side of bearing 16 facing the rotor assembly 4, the inner ring of bearing 16 is positioned by the shoulder on the outer circumferential surface of the shaft 6, and the outer ring of bearing 16 is positioned by the annular flange edge inside the housing 1.

[0063] See Figure 2 As shown by the middle arrow, the cooling medium enters the central hole 7 of the shaft from one end of the rotating shaft 6, passes through the connecting channel and then turns back through the bearing 16, enters the first axial gap 3 and the first radial gap 5, and flows out from the same end of the rotating shaft 6, forming a cooling channel for the motor rotor and the bearing 16.

[0064] A magnet holder with an induction magnet 10 is embedded in the end of the rotating shaft 6, and a connecting channel is provided on the magnet holder to connect the shaft center hole 7 of the rotating shaft 6, so that the cooling medium entering the shaft center hole 7 from one end flows to the other end of the rotating shaft 6. After flowing out from the connecting channel, it flows back through the bearing 16 installed at the end of the rotating shaft 6 to cool the bearing 16. After passing the bearing 16, it enters the first radial gap 5 along the first axial gap 3 between the stator assembly 2 and the rotor assembly 4 and flows back to the side where the cooling medium enters. The outflow side and the inflow side of the cooling medium are on the same side of the rotor assembly 4, forming a circulating and unobstructed cooling channel. This not only achieves effective cooling of the bearing 16, but also achieves effective cooling of the rotor assembly 4 as a whole, thereby greatly improving the cooling and heat dissipation effect of the bearing 16 and the rotor.

[0065] The bearing 16 in this application is both the object being cooled and a component of the cooling channel. The cooling medium flows directly through the internal gap of the bearing 16, which not only effectively cools the bearing 16, but also reduces the structural increase caused by setting holes or gaps for the cooling medium to pass through, thus optimizing the structure of the motor.

[0066] In some embodiments, see Figure 1 As shown, the magnet base includes a magnet fixing base 11 and an induction magnet 10 embedded in the magnet fixing base 11. The induction magnet 10 and the Hall plate 17 have a third axial gap 12, which communicates with the second axial gap 15. The center hole 9, the connecting hole 13 and the second radial gap 14 are provided on the magnet fixing base 11.

[0067] Compared with the cooling method of setting a central hole through the induction magnet 10, the above-mentioned technical solution does not pass through the induction magnet 10 in the communication channel of this application. It does not require setting a hole or channel for the cooling medium to pass through on the induction magnet 10. Therefore, it will not damage the integrity of the induction magnet 10 and can maintain the inherent characteristics of the induction rotation speed of the induction magnet 10 to ensure the accuracy of the induction shaft rotation speed.

[0068] The induction magnet 10 is embedded in the magnet mounting base 11, and the connecting channel is set in the magnet mounting base 11 without compromising the integrity of the induction magnet 10. The induction magnet 10 is enclosed by the magnet mounting base 11, and the outer end face of the induction magnet 10 is flush with the outer end face of the magnet mounting base 11 to reduce the axial length of the rotating shaft 6 and to avoid interference with the Hall effect partition 17 at the end. The third axial gap 12 formed at the same time also constitutes part of the cooling channel. The axis of the induction magnet 10 coincides with the axis of the rotating shaft 6 to ensure the accuracy of the rotational speed of the induction rotating shaft 6.

[0069] In the above technical solution, the induction magnet 10 is mounted on the end of the rotating shaft 6 via the magnet mounting base 11. This provides the inherent characteristic of sensing the rotational speed of the rotating shaft 6, and also provides a communication channel for the cooling medium through the magnet mounting base 11. This allows the cooling medium to flow from the oil pump end through the shaft center hole 7 of the rotating shaft 6 to the end where the bearing 16 is mounted, thus providing flow cooling to the bearing 16. This structural design not only reduces the number of parts but also avoids compromising the integrity of core components such as the stator assembly 2 and the rotor assembly 4. Furthermore, it maintains the overall dimensions of the motor or facilitates a reduction in the overall dimensions of the motor, thereby optimizing the motor structure.

[0070] In some embodiments, see Figure 1As shown, the magnet fixing seat 11 has an interference fit section that is interference-fitted into the rotating shaft 6 and a clearance fit section that is clearance-fitted into the rotating shaft 6. The connecting hole 13 is provided in the clearance fit section. The clearance between the clearance fit section and the rotating shaft forms a second radial clearance 14. The seat center hole 9 is provided in the interference fit section. The diameter of the clearance fit section is larger than that of the interference fit section, forming an axial limiting surface. An axial stop surface that can abut against the axial limiting surface is provided in the rotating shaft 6 to limit the axial embedding depth of the magnet fixing seat 11.

[0071] In the above technical solution, a simple change to the structure of the magnet fixing seat 11 can achieve synchronous rotation with the rotating shaft 6 after installation, and can also directly form a second radial gap 14 between the rotating shaft 6 and the magnet fixing seat 11, forming part of the cooling channel. While considering the passage of cooling medium by means of the magnet fixing seat 11, the optimization of the overall structure of the motor is also considered, thus achieving the purpose of optimizing the motor structure.

[0072] There is no gap between the interference fit section of the magnet fixing seat 11 and the rotating shaft 6, which prevents the possibility of the cooling medium passing between them; the gap fit section is used to form the second radial gap 14 of the cooling channel. This second radial gap 14 is an annular gap, which ensures the smooth flow of the cooling medium.

[0073] The installation of the magnet fixing seat 11 relies on the interference fit to form a radial limit, and on the axial limiting surface formed on the clearance fit section to abut against the axial stop surface inside the rotating shaft 6, thus limiting the depth of the magnet fixing seat 11 installed into the rotating shaft 6.

[0074] In some embodiments, see Figure 1 As shown, the magnet base has multiple connecting holes 13 arranged along the circumferential direction.

[0075] In the above technical solution, multiple connecting holes 13 are uniformly arranged along the circumferential direction, and the multiple connecting holes 13 connect to the annular second radial gap 14 to ensure the smooth flow of the cooling medium.

[0076] The connecting hole 13 can be set at an angle or radially along the magnet fixing base 11.

[0077] In some embodiments, see Figure 1 As shown, the diameter of the shaft center hole 7 is greater than the diameter of the seat center hole 9, the diameter of the seat center hole 9 is greater than the diameter of the connecting hole 13, and the diameter of the connecting hole 13 is greater than the radial width of the second radial gap 14.

[0078] In the above technical solution, the diameter or width of the cooling channel gradually decreases from the oil inlet end of the cooling medium to the direction away from the oil inlet end, which makes up for the energy loss of the cooling medium during the flow process, so as to ensure the pressure and flow rate of the cooling medium at each stage, which is conducive to improving the cooling effect and also conducive to the smooth flow of the cooling medium between different parts, while also reducing the risk of blockage that may occur due to excessively small gaps.

[0079] In the above technical solution, the diameter or width of the cooling channel gradually decreases from the oil inlet end of the cooling medium towards the direction away from the oil inlet end. This design is based on the formula Q=A⋅v, where A is the cross-sectional area and is constant, and v is the flow velocity. When the diameter decreases, A decreases, and the flow velocity v must increase. High-speed flowing oil can more efficiently remove heat and avoid local overheating.

[0080] In some embodiments, see Figure 1 As shown, the axial width of the first axial gap 3 is greater than the radial width of the first radial gap 5.

[0081] In the above technical solution, the aperture or width of the cooling channel gradually decreases from the direction of the cooling medium return flow, which can increase the flow rate of the cooling medium. The high-speed flowing oil can carry away heat more efficiently and avoid local overheating.

[0082] Based on the same inventive concept, this application also provides a motor, see [link to relevant documentation]. Figure 1 As shown, it includes a rotating shaft 6, a rotor assembly 4 mounted on the rotating shaft 6, and a stator assembly 2 mounted outside the rotor assembly 4; a magnet seat is embedded in the end of the rotating shaft 6, and the shaft center hole 7 on the rotating shaft 6, the connecting channel on the magnet seat, the clearance of the bearing 16, the first axial clearance 3 and the first radial clearance 5 together constitute the cooling channel of the rotor and the bearing 16.

[0083] This design, incorporating a magnet seat that senses the rotational speed of the rotating shaft 6 within the shaft 6 and also forming part of the cooling channel, does not increase the axial length of the rotating shaft 6 or change the original length of the bearing 16. While optimizing the cooling channel and improving the cooling and heat dissipation effect of the rotor and bearing 16, it also optimizes the overall structure of the motor, saves internal space, and improves the performance of the motor.

[0084] Based on the same inventive concept, this application also provides a vehicle that utilizes the aforementioned motor.

[0085] The vehicle provided in this application improves its performance by using a motor with good cooling and optimized structure.

[0086] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A cooling structure for an electric motor rotor, characterized in that, include: The rotating shaft (6) is a hollow shaft with a central hole (7); A magnet base is embedded in one end of the rotating shaft (6), and the magnet base has a communicating channel that connects to the central hole (7) of the shaft; The rotor assembly (4) is mounted on the rotating shaft (6) and rotates synchronously with the rotating shaft (6); The stator assembly (2) is fitted over the outside of the rotor assembly (4) and has a first axial gap (3) between itself and the end of the rotor assembly (4) in the axial direction and a first radial gap (5) between itself and the circumferential surface of the rotor assembly (4) in the radial direction. The cooling medium enters the shaft center hole (7) from one end of the shaft (6), and enters the first axial gap (3) and the first radial gap (5) after passing through the connecting channel. The outflow side and the inflow side of the cooling medium are on the same side of the rotor assembly (4), forming the cooling channel of the motor rotor.

2. The cooling structure for the motor rotor as described in claim 1, characterized in that, The magnet seat is partially interference-fitted with the rotating shaft (6) and partially clearance-fitted with the rotating shaft (6) to form a second radial clearance (14); the interference-fitted part of the magnet seat has a seat center hole (9) that connects to the shaft center hole (7), and the magnet seat is provided with a connecting hole (13) that connects the seat center hole (9) and the second radial clearance (14); the seat center hole (9), the connecting hole (13) and the second radial clearance (14) constitute the connecting channel.

3. The cooling structure for the motor rotor as described in claim 2, characterized in that, There is a second axial gap (15) between the bearing (16) at the end of the shaft (6) and the Hall plate (17) that seals the bearing (16); the second axial gap (15) communicates with the second radial gap (14) and forms part of the cooling channel.

4. The cooling structure for the motor rotor as described in claim 3, characterized in that, The magnet base includes a magnet fixing base (11) and an induction magnet (10) embedded in the magnet fixing base (11). The induction magnet (10) and the Hall plate (17) have a third axial gap (12), which communicates with the second axial gap (15). The center hole (9), the connecting hole (13), and the second radial gap (14) are disposed on the magnet fixing base (11).

5. The cooling structure for the motor rotor as described in claim 4, characterized in that, The magnet fixing seat (11) has an interference fit section that is interference fit with the rotating shaft (6) and a clearance fit section that is clearance fit with the rotating shaft (6). The connecting hole (13) is disposed in the clearance fit section. The clearance between the clearance fit section and the rotating shaft constitutes the second radial clearance (14). The seat center hole (9) is disposed in the interference fit section. The diameter of the clearance fit section is larger than that of the interference fit section, constituting an axial limiting surface. An axial stop surface that can abut against the axial limiting surface is provided in the rotating shaft (6) to limit the axial embedding depth of the magnet fixing seat (11).

6. The cooling structure for the motor rotor as described in claim 2, characterized in that, The magnet base has multiple connecting holes (13) arranged along the circumferential direction.

7. The cooling structure for the motor rotor as described in claim 2, characterized in that, The diameter of the shaft center hole (7) is greater than the diameter of the seat center hole (9), the diameter of the seat center hole (9) is greater than the diameter of the connecting hole (13), and the diameter of the connecting hole (13) is greater than the radial width of the second radial gap (14).

8. The cooling structure for the motor rotor as described in claim 1, characterized in that, The axial width of the first axial gap (3) is greater than the radial width of the first radial gap (5).

9. An electric motor, characterized in that, The cooling structure includes the motor rotor as described in any one of claims 1-8.

10. A vehicle, characterized in that, Includes the motor as described in claim 9.

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