Motor

Abstract

The utility model discloses a motor. The motor comprises a rotor assembly, a guiding member and a stator assembly. The rotor assembly comprises a shell, a first containing cavity is defined by the shell, the guide part is connected with the shell and located in the first containing cavity, a second containing cavity is defined in the guide part, a cooling medium is arranged in the second containing cavity, the stator assembly penetrates through the shell, and the guide part and the stator assembly are movably matched in the first containing cavity. The rotor assembly moves relative to the stator assembly. Therefore, the cooling medium is arranged in the second accommodating cavity, when the motor works, the cooling medium oscillates up and down along with the movement of the guide piece, and the oscillated cooling medium transmits heat generated in the motor to the outside of the motor, so that reliable operation of the motor is ensured, and the production cost and the after-sales maintenance cost of the motor are reduced.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 2023118630476 entitled “Electric Motor”, filed by BYD Company Limited on December 29, 2023. Technical Field

[0003] This utility model relates to the field of motor technology, and in particular to a motor. Background Technology

[0004] In the existing technology, linear motors lack a cooling structure, making them unable to operate under high current conditions. The peak thrust and rated thrust of the motor output are both too small. When the motor power is large, a large amount of heat is generated in the motor windings, causing the internal temperature of the motor to exceed the limit, resulting in phenomena such as high-temperature demagnetization of the magnets and burnt-out windings, which greatly reduces the reliability and durability of the motor. Utility Model Content

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one objective of the present invention is to provide a motor that can reduce the temperature of its various components and ensure reliable operation.

[0006] An electric motor according to an embodiment of the present invention includes a rotor assembly, a guide member, and a stator assembly. The rotor assembly includes a housing defining a first receiving cavity. The guide member is connected to the housing and located within the first receiving cavity. A second receiving cavity is defined within the guide member, and the second receiving cavity is adapted to contain a cooling medium. The stator assembly passes through the housing, and the guide member movably engages with a portion of the stator assembly within the first receiving cavity. The rotor assembly is movable relative to the stator assembly.

[0007] According to the embodiment of the present invention, the motor has a second receiving cavity provided in the guide member, and a cooling medium is provided in the second receiving cavity. When the motor is working, as the guide member moves relative to the stator assembly along the axial direction of the stator assembly, the cooling medium in the guide member oscillates up and down with the movement of the guide member. The oscillating cooling medium transfers the heat generated inside the motor to the outside of the motor for effective cooling, thereby reducing the temperature of the various parts inside the motor and ensuring that the rotor assembly and stator assembly operate within a tolerable temperature range. This ensures reliable operation of the motor, reduces unnecessary fault repairs, and lowers the production cost and after-sales maintenance cost of the motor.

[0008] In some embodiments, a portion of the stator assembly located within the first receiving cavity is formed with a cavity, and the guide is movably fitted within the cavity along the axial direction of the stator assembly.

[0009] In some embodiments, the shell comprises a shell body and an end cover, a through hole is formed on the end cover, the guide is connected to a side of the end cover adjacent to the center of the shell body, a through cavity is formed in the guide and communicates with the through hole, and the through cavity and the through hole jointly form the second accommodating cavity.

[0010] In some embodiments, a cross-sectional area of the through hole is greater than a cross-sectional area of the through cavity.

[0011] In some embodiments, the through hole comprises a first through hole section and a second through hole section, the second through hole section is connected between the first through hole section and the through cavity, a cross-sectional area of the first through hole section is greater than a cross-sectional area of the through cavity, and a cross-sectional area of one end of the second through hole section connected to the first through hole section is greater than a cross-sectional area of one end of the second through hole section connected to the through cavity.

[0012] In some embodiments, the cross-sectional area of the second through hole section gradually decreases in a direction towards the center of the shell body, or the cross-sectional area of the second through hole section is equal everywhere.

[0013] In some embodiments, the stator assembly comprises a stator and a coil, the coil is arranged on an outer circumferential side of the stator, and a projection of the coil in a radial direction of the stator at least partially overlaps with a projection of the second accommodating cavity in the radial direction of the stator.

[0014] In some embodiments, a volume of the cooling medium is less than a volume of the second accommodating cavity.

[0015] In some embodiments, the second accommodating cavity is a fully-enclosed accommodating cavity.

[0016] In some embodiments, a bearing is arranged between an inner wall of the cavity and the guide.

[0017] In some embodiments, one end of the cavity is open, a limiting member is arranged in the cavity, and the limiting member is located at one end of the bearing adjacent to the open end of the cavity to limit movement of the bearing in the cavity.

[0018] In some embodiments, the through hole penetrates through two side surfaces of the end cover in an axial direction of the stator assembly, a yoke is arranged on a side of the end cover away from the center of the shell body, and the yoke covers one end of the through hole away from the center of the shell body.

[0019] In some embodiments, a groove is formed on the yoke and communicates with the through hole.

[0020] In some embodiments, a magnetic steel is arranged on an inner wall of the first accommodating cavity.

[0021] The additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter in the description of embodiments of the present application, which will be described with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0022] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description of embodiments of the present application, taken in conjunction with the accompanying drawings.

[0023] Figure 1 is a schematic view of a motor according to an embodiment of the present application.

[0024] Figure 2 is a cross-sectional schematic view of a motor according to an embodiment of the present application.

[0025] REFERENCE NUMERALS

[0026] 100, motor;

[0027] 10, rotor assembly; 11, housing; 111, housing body; 12, end cover; 121, communication hole; 1211, first communication hole section; 1212, second communication hole section; 13, guide member; 131, communication cavity; 14, first accommodating cavity; 15, second accommodating cavity; 16, magnetic steel; 17, mounting bearing; 18, fastener;

[0028] 20, stator assembly; 21, cavity; 22, bearing; 23, stator winding; 24, limiting member;

[0029] 30, yoke; 31, groove;

[0030] A, height direction. DETAILED DESCRIPTION

[0031] Embodiments of the present application will be described in detail below with reference to the accompanying drawings. The embodiments described with reference to the accompanying drawings are exemplary, and the following description is made with reference to Figures 1-2 A motor 100 according to an embodiment of the present application will be described. The motor 100 includes a rotor assembly 10, a guide member, and a stator assembly 20. The motor 100 has a height direction A.

[0032] Specifically, as shown in Figure 1 and Figure 2 , the rotor assembly 10 includes a housing 11 defining a first accommodating cavity 14, the guide member 13 is connected to the housing 11, the guide member 13 is located in the first accommodating cavity 14, the guide member 13 defines a second accommodating cavity 15 therein, and the second accommodating cavity 15 is adapted to be provided with a cooling medium. The stator assembly 20 is provided in the housing 11, the portion of the guide member 13 and the stator assembly 20 in the first accommodating cavity 14 is movably coupled, and the rotor assembly 10 moves relative to the stator assembly 20.

[0033] In combination Figure 2 In the embodiment, the guide 13 extends towards the center of the housing 11. The housing 11 is open at one end along the height direction A of the motor 100, and the first accommodating cavity 14 is adapted to be opposite to the open end of the housing 11. A mounting hole is formed on the other end of the housing 11 along the height direction A of the motor 100, and the mounting hole is used to assemble the stator assembly 20. The mounting bearing 17 is arranged at the mounting hole, and the mounting bearing 17 is mounted on the outside of the housing 11 away from the open end of the housing 11 along the height direction A of the motor 100 by the fastener 18. At least part of the stator assembly 20 is located in the first accommodating cavity 14, that is, one end of the stator assembly 20 along the height direction A of the motor 100 is located in the first accommodating cavity 14. The stator winding 23 is arranged on the end of the stator assembly 20 located in the first accommodating cavity 14. The other end of the stator assembly 20 along the height direction A of the motor 100 penetrates the mounting hole and the mounting bearing 17, and extends out of the housing 11. The guide 13 cooperates with the stator assembly 20 along the height direction A of the motor 100 and can move relatively. The guide 13 moves relative to the stator assembly 20 when the rotor assembly 10 moves relative to the stator assembly 20 along the axial direction of the stator assembly 20. When the motor 100 works, the stator winding 23 generates a magnetic field, which can be an alternating magnetic field, that is, the direction of the magnetic field alternately changes, and then the rotor assembly 10 moves relative to the stator assembly 20 along the axial direction of the stator assembly 20, that is, the height direction A of the motor 100, to drive the guide 13 to move relative to the axial direction of the stator assembly 20. The second accommodating cavity 15 in the guide 13 is provided with a cooling medium. When the guide 13 moves, the cooling medium also oscillates in the second accommodating cavity 15 with the movement of the guide 13, increases the area of the cooling medium in contact with the motor 100, and realizes heat dissipation of the guide 13 and the inside of the motor 100, avoiding the risk of bending and creeping of the guide 13 due to heat.

[0034] According to the motor 100 of the embodiment of the utility model, the second accommodating cavity 15 is arranged in the guide 13, and the cooling medium is arranged in the second accommodating cavity 15. When the motor 100 works, the cooling medium in the guide 13 oscillates up and down with the movement of the guide 13 in the process that the guide 13 moves relative to the stator assembly 20 along the axial direction of the stator assembly 20. The oscillating cooling medium transfers the heat generated in the motor 100 to the outside of the motor 100 for effective cooling, so as to reduce the temperature of each part in the motor 100, make the rotor assembly 10 and the stator assembly 20 work in a bearable temperature range, ensure the reliable operation of the motor 100, reduce unnecessary fault maintenance, and reduce the production cost and after-sales maintenance cost of the motor 100.

[0035] According to some embodiments of the utility model, Figure 2As shown, the portion of the stator assembly 20 located in the first accommodating cavity 14 is formed with a cavity 21, and the guide 13 is movably fitted in the cavity 21 along the axial direction of the stator assembly 20. That is, the end of the stator assembly 20 located in the first accommodating cavity 14 along the height direction A of the motor 100 is internally formed with the cavity 21, the cavity 21 extends along the height direction A of the motor 100, and the guide 13 can move up and down in the cavity 21 along the height direction A of the motor 100 with respect to the stator assembly 20. Thus, the cavity 21 defines a movement track for the guide 13, increases the accuracy of the movement of the guide 13 in the cavity 21, the guide 13 is provided with a cooling medium, and when the guide 13 moves up and down in the cavity 21 along the axial direction of the stator assembly 20, the cooling medium moves in the guide 13 along with the guide 13, and the cooling medium can exchange heat with the heat transferred to the guide 13 in the cavity 21, so that the heat generated by the stator assembly 20 during operation can be transferred to the cooling medium through the guide 13 to achieve the purpose of cooling.

[0036] According to some embodiments of the present application, Figure 2 As shown, the shell 11 includes a shell body 111 and an end cover 12, the end cover 12 is formed with a communication hole 121, the communication hole 121 at least penetrates through the side surface of the end cover 12 adjacent to the center of the shell body 111, the guide 13 is connected to the side of the end cover 12 adjacent to the center of the shell body 111, the guide 13 is internally formed with a communication cavity 131 communicated with the communication hole 121, and the communication cavity 131 and the communication hole 121 jointly constitute a second accommodating cavity 15. The guide 13 is arranged on the side of the end cover 12 facing the first accommodating cavity 14 along the height direction A of the motor 100, the guide 13 extends along the height direction A of the motor 100, the communication cavity 131 located in the interior of the guide 13 extends along the height direction A of the motor 100, the communication cavity 131 and the communication hole 121 communicate to define the second accommodating cavity 15, the cooling medium is located in the second accommodating cavity 15, and the cooling medium can oscillate and flow in the communication hole 121 and the communication cavity 131 when the guide 13 moves. Thus, during the downward movement of the rotor assembly 10 with respect to the stator assembly 20 along the height direction A of the motor 100, the cooling medium in the second accommodating cavity 15 flows upward along the height direction A of the motor 100 into the communication cavity 131 under the action of inertia, the cooling medium contacts the inner wall of the communication cavity 131 to absorb heat, the communication cavity 131 is arranged to facilitate the cooling medium to enter the interior of the motor 100 and contact the motor 100, so that the temperature of the stator assembly 20 and the bearing 22 can be more efficiently reduced, the contact area between the cooling medium and the inner wall of the guide 13 is increased, and the heat dissipation effect is improved.

[0037] According to some embodiments of the present application, Figure 2As shown, the cross-sectional area of the communication hole 121 is greater than the cross-sectional area of the communication cavity 131. The cross-sectional area of the communication hole 121 being greater than the cross-sectional area of the communication cavity 131 facilitates reducing the resistance of the communication hole 121 to the flow of the cooling medium when the cooling medium enters the communication hole 121 from the communication cavity 131, so that the flow of the cooling medium in the second accommodating cavity 15 is smoother. When the cooling medium enters the communication cavity 131 through the communication hole 121, the resistance of the communication hole 121 to the flow of the cooling medium can be increased, the flow rate of the cooling medium in the communication cavity 131 is reduced, the residence time of the cooling medium in the communication cavity 131 is prolonged, and the heat dissipation efficiency of the cooling medium is improved, so that the cooling effect is better, and the temperature of the motor 100 is reduced, so that the motor 100 can work normally under a larger current.

[0038] According to some embodiments of the present application, as shown in Figure 2 As shown, the communication hole 121 includes a first communication hole section 1211 and a second communication hole section 1212, the second communication hole section 1212 is connected between the first communication hole section 1211 and the communication cavity 131, the cross-sectional area of the first communication hole section 1211 is greater than the cross-sectional area of the communication cavity 131, and the cross-sectional area of one end of the second communication hole section 1212 connected with the first communication hole section 1211 is greater than the cross-sectional area of one end of the second communication hole section 1212 connected with the communication cavity 131. That is, the communication cavity 131, the second communication hole section 1212 and the first communication hole section 1211 are sequentially arranged in the direction of the height A of the motor 100 towards the direction close to the end cover 12, wherein the cross-sectional area of the communication cavity 131 is equal everywhere, the cross-sectional area of the second communication hole section 1212 is greater than the cross-sectional area of the communication cavity 131, and the cross-sectional area of the first communication hole section 1211 is greater than the cross-sectional area of the second communication hole section 1212. Therefore, the cross-sectional area of the second communication hole section 1212 is greater than the cross-sectional area of the communication cavity 131, and the cross-sectional area of the first communication hole section 1211 is greater than the cross-sectional area of the second communication hole section 1212, which can facilitate the flow of the cooling medium between the communication hole 121 and the communication cavity 131, and effectively improve the heat dissipation effect of the cooling medium.

[0039] According to some embodiments of the present application, as shown in Figure 2 As shown, the cross-sectional area of the second communication hole section 1212 gradually decreases towards the center of the shell body 11, or the cross-sectional area of the second communication hole section 1212 is equal everywhere. During the process of the rotor assembly 10 moving up and down relative to the stator assembly 20 in the height direction A of the motor 100, the cooling medium can oscillate between the first communication hole section 1211, the second communication hole section 1212 and the communication cavity 131 under the action of inertia. Therefore, the cross-sectional area of the second communication hole section 1212 gradually decreasing towards the center of the shell body 11 can make the flow of the cooling medium in the second accommodating cavity 15 more smooth, and also facilitate controlling the flow rate of the cooling medium, prolonging the residence time of the cooling medium in the communication cavity 131, and ensuring the heat dissipation effect.

[0040] According to some embodiments of the present application, the stator assembly 20 comprises a stator and a coil, the coil is arranged on the outer circumferential side of the stator, the projection of the coil in the radial direction of the stator at least partially overlaps the projection of the second accommodating cavity 15 in the radial direction of the stator. The coil will generate a certain amount of heat during operation, and the projection of the coil in the radial direction of the stator at least partially overlaps the projection of the second accommodating cavity 15 in the radial direction of the stator, which ensures that the heat generated by the coil can be transmitted to the second accommodating cavity 15 through the stator, so that the cooling medium in the second accommodating cavity 15 can take away the heat, and the heat exchange process is completed.

[0041] According to some embodiments of the present application, the volume of the cooling medium is smaller than the volume of the second accommodating cavity 15. The second accommodating cavity 15 is suitable for filling the cooling medium, and when the rotor assembly 10 moves up and down relative to the stator assembly 20 along the height direction A of the motor 100, the cooling medium oscillates up and down in the second accommodating cavity 15 with the movement of the rotor assembly 10, and the cooling medium takes away the heat generated by the stator assembly 20 during oscillation. Therefore, the volume of the cooling medium is smaller than the volume of the second accommodating cavity 15, so that the cooling medium can oscillate and flow in the second accommodating cavity 15, and the cooling effect of the stator assembly 20 is realized.

[0042] According to some embodiments of the present application, the second accommodating cavity 15 is a fully enclosed accommodating cavity. The cooling medium oscillates and flows in the second accommodating cavity 15, and the second accommodating cavity 15 is a fully enclosed accommodating cavity, which can avoid leakage of the cooling medium, improve the overall structural strength of the motor 100, ensure the stability of the motor 100 movement, and prolong the service life of the motor 100.

[0043] According to some embodiments of the present application, as shown in Figure 2 The inner wall of the cavity 21 and the guide 13 are provided with a bearing 22. The bearing 22 extends along the height direction A of the motor 100, the bearing 22 is arranged in the cavity 21, the outer wall of the bearing 22 is attached to the inner wall of the cavity 21, the guide 13 is arranged in the bearing 22, the outer wall of the guide 13 is attached to the inner wall of the bearing 22, and when the guide 13 moves relative to the stator assembly 20 in the axial direction of the stator assembly 20 in the cavity 21, the guide 13 also moves relative to the bearing 22 in the axial direction of the bearing 22. Therefore, the arrangement of the bearing 22 can reduce the friction between the guide 13 and the stator assembly 20 during the movement of the guide 13, and make the relative movement between the guide 13 and the stator assembly 20 more smooth. When the motor 100 works, the heat generated by the stator assembly 20 can be conducted to the guide 13 through the bearing 22, and then conducted to the outside of the motor 100 through the cooling medium, so as to realize the heat dissipation of the motor 100, and at the same time reduce the risk of gumming of the lubricating oil on the bearing 22 due to the high temperature of the stator assembly 20.

[0044] According to some embodiments of the present application, as shown inFigure 2 As shown, one end of the cavity 21 is open, and a limiting piece 24 is arranged in the cavity 21, and the limiting piece 24 is located at the open end of the cavity 21 of the bearing 22 to limit the movement of the bearing 22 in the cavity 21. The bearing 22 is assembled into the cavity 21 of the stator assembly 20 from the open end of the cavity 21, and the bearing 22 is further assembled into the limiting piece 24 at the end close to the open end of the cavity 21 along the height direction A of the motor 100 to be locked and positioned. The limiting piece 24 has a through hole for cooperating with the guide piece 13 to enable the guide piece 13 to be fitted in the bearing 22 away from the other end of the open end of the cavity 21 along the height direction A of the motor 100. Thus, the limiting piece 24 is arranged at the end of the bearing 22 adjacent to the open end of the cavity 21, and the limiting piece 24 can lock and position the bearing 22 in the height direction A of the motor 100, preventing the limiting piece 24 from being separated from the cavity 21, and improving the stability of the assembly structure of the motor 100.

[0045] According to some embodiments of the present application, as Figure 2 As shown, the communication hole 121 penetrates through the two side surfaces of the end cover 12 along the axial direction of the stator assembly 20, and the end cover 12 is provided with a yoke 30 away from the center of the shell body 111, and the yoke 30 covers one end of the communication hole 121 away from the center of the shell body 111. The end cover 12 is provided with a yoke 30 away from the stator assembly 20 along the height direction A of the motor 100, and the yoke 30 is connected to the end cover 12 at the end close to the stator assembly 20 along the height direction A of the motor 100 assembly, and the yoke 30 and the end cover 12 are connected together by welding, and the yoke 30 and the end cover 12 are connected together by welding, which can effectively improve the connection strength of the yoke 30 and the end cover 12. In some embodiments, the motor 100 is adapted to be installed on a vehicle, and the end of the yoke 30 away from the end cover 12 along the height direction A of the motor 100 is used to abut against the axle of the vehicle to adjust the height of the vehicle. Thus, the end of the yoke 30 covering the communication hole 121 can cooperate with the side of the end cover 12 away from the center of the shell body 111 to form a second accommodating cavity 15, and when the cooling medium in the second accommodating cavity 15 contacts the guide piece 13 to take away the heat on the guide piece 13, the temperature of the cooling medium is increased at this time, and the high-temperature cooling medium contacts the yoke 30 as the oscillation continues, and the cooling medium transmits heat to the yoke 30, and the yoke 30 transmits heat to the outside to realize heat dissipation inside the motor 100, and the heat dissipation area of the yoke 30 is large, which can effectively improve the heat dissipation efficiency of the motor 100.

[0046] According to some embodiments of the present application, as Figure 2As shown, the yoke 30 is formed with a groove 31 communicating with the communication hole 121. The groove 31 is arranged at one end of the yoke 30 close to the stator assembly 20 along the height direction A of the motor 100, the groove 31 is arranged opposite to the communication hole 121, and the cross-sectional area of the groove 31 is equal to the cross-sectional area of the communication hole 121 at the connection position of the communication hole 121 and the yoke 30, so as to facilitate the connection of the yoke 30 and the end cover 12. The groove 31 is arranged to facilitate the fitting with the communication hole 121 to form the second containing cavity 15, and facilitate the arrangement of the cooling medium. Therefore, the arrangement of the groove 31 can increase the internal volume of the second containing cavity 15, the cooling medium can transfer heat to the yoke 30 by contacting the inner wall of the groove 31, and the heat can be transferred to the outside through the yoke 30, thereby effectively improving the heat exchange efficiency of the cooling medium, and realizing the cooling of the motor 100.

[0047] According to some embodiments of the present application, Figure 2 Figure 2 As shown, the inner wall of the first containing cavity 14 is provided with a magnetic steel 16. The stator assembly 20 is provided with a plurality of tooth slots on the outer peripheral side of one end located in the first containing cavity 14 along the height direction A of the motor 100, and the plurality of tooth slots are arranged on the stator assembly 20 along the height direction A of the motor 100. Each tooth slot is wound with a copper wire to form a stator winding 23. The magnetic steel 16 is arranged on the inner wall of the first containing cavity 14, that is, the magnetic steel 16 is arranged around the stator winding 23. After the motor 100 is powered on, the stator winding 23 generates a magnetic field, and the magnetic field generated by the stator winding 23 interacts with the magnetic field of the magnetic steel 16. The magnetic steel 16 moves back and forth along the height direction A of the motor 100 under the influence of the magnetic field, and the rotor assembly 10 moves up and down relative to the stator assembly 20 along the axial direction of the stator assembly 20. That is, the shell body 111, the end cover 12 and the magnetic steel 16 arranged in the shell body 111 move back and forth relative to the stator assembly 20 along the height direction A of the motor 100 in the alternating magnetic field formed by the stator assembly 20. During the movement of the rotor assembly 10, the cooling medium in the guide 13 oscillates in the second containing cavity 15 along with the movement of the rotor assembly 10. The cooling medium absorbs the heat generated by the stator winding 23 during the operation of the motor 100, the heat generated by the alternating magnetic flux density in the magnetic steel 16, and the heat generated by the relative motion friction between the stator assembly 20 and the rotor assembly 10 during the oscillation process, and transfers the heat to the outside through the end cover 12 and the yoke 30. The temperature of each part in the motor 100 is reduced, the motor 100 is effectively cooled, the reliable operation of the stator assembly 20 and the rotor assembly 10 is ensured, the service life of the motor 100 is prolonged, and the production cost and the after-sales maintenance cost of the product are reduced.

[0048] In the description of the utility model, need understanding is, the term "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and so on the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawing, just is for the convenience of describing the utility model and simplifying the description, and not indicate or imply the device or element indicated must have a particular orientation, with a particular orientation configuration and operation, therefore can not be understood as the restriction of the utility model.

[0049] In the description of the utility model, "first feature", "second feature" can include one or more features.In the description of the utility model, "multiple" means two or more than two.In the description of the utility model, the first feature is "on" or "below" the second feature can include that the first and second features are in direct contact, or the first and second features are not in direct contact but are in contact through another feature between them.In the description of the utility model, the first feature is "on", "above" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is horizontally higher than the second feature.

[0050] In the description of the specification, the description of the reference terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model.In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example.

[0051] Although the embodiments of the utility model have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and purposes of the utility model, and the scope of the utility model is defined by the claims and its equivalents.

Claims

1. An electric motor, characterized in that, include: A rotor assembly, the rotor assembly including a housing defining a first receiving cavity; A guide member is connected to the housing and is located within the first receiving cavity. A second receiving cavity is defined within the guide member, and the second receiving cavity is adapted to contain a cooling medium. A stator assembly passing through the housing, a guide member movably engaging with the stator assembly within the first receiving cavity, and a rotor assembly movable relative to the stator assembly.

2. The motor according to claim 1, characterized in that, The portion of the stator assembly located within the first receiving cavity has a cavity, and the guide member is movably fitted within the cavity along the axial direction of the stator assembly.

3. The motor according to claim 1, characterized in that, The housing includes a housing body and an end cap, and a communicating hole is formed on the end cap; The guide is connected to the side of the end cap adjacent to the center of the shell body, and a communicating cavity is formed in the guide that communicates with the communicating hole. The communicating cavity and the communicating hole together constitute the second receiving cavity.

4. The motor according to claim 3, characterized in that, The cross-sectional area of ​​the connecting hole is larger than the cross-sectional area of ​​the connecting cavity.

5. The motor according to claim 3, characterized in that, The connecting hole includes a first connecting hole segment and a second connecting hole segment. The second connecting hole segment is connected between the first connecting hole segment and the connecting cavity. The cross-sectional area of ​​the first connecting hole segment is larger than the cross-sectional area of ​​the connecting cavity. The cross-sectional area of ​​the end of the second connecting hole segment connected to the first connecting hole segment is larger than the cross-sectional area of ​​the end of the second connecting hole segment connected to the connecting cavity.

6. The motor according to claim 5, characterized in that, The cross-sectional area of ​​the second connecting hole segment gradually decreases along the direction toward the center of the shell body; or the cross-sectional area of ​​the second connecting hole segment is equal everywhere.

7. The motor according to claim 1, characterized in that, The stator assembly includes a stator and a coil, the coil being disposed on the outer periphery of the stator, and the projection of the coil in the radial direction of the stator at least partially coinciding with the projection of the second receiving cavity in the radial direction of the stator.

8. The motor according to claim 1, characterized in that, The volume of the cooling medium is smaller than the volume of the second accommodating cavity.

9. The motor according to claim 1, characterized in that, The second receiving cavity is a fully enclosed receiving cavity.

10. The motor according to claim 2, characterized in that, A bearing is provided between the inner wall of the cavity and the guide member.

11. The motor according to claim 10, characterized in that, One end of the cavity is open, and a limiting member is provided inside the cavity. The limiting member is located near the open end of the cavity adjacent to the bearing to limit the movement of the bearing within the cavity.

12. The motor according to claim 3, characterized in that, The connecting hole extends through both sides of the end cap along the axial direction of the stator assembly; The end cap has a fork on the side away from the center of the shell body, and the fork covers the end of the connecting hole away from the center of the shell body.

13. The motor according to claim 12, characterized in that, The fork has a groove that communicates with the connecting hole.

14. The motor according to any one of claims 1-13, characterized in that, The inner wall of the first receiving cavity is provided with a magnet.

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