Electric motor and electric drive system

Abstract

The utility model provides a motor and an electric drive system. The motor comprises a shell, the shell comprises a shell body, a first end cover and a second end cover, the first end cover and the second end cover are connected to the shell body, and the first end cover is internally provided with an end cover channel; the isolation cylinder is connected to the first end cover and the second end cover so as to divide the interior of the shell into a stator cavity and a rotor cavity; the stator is arranged in the stator cavity, the stator divides the stator cavity into a first cavity and a second cavity which are located on the two sides of the stator cavity in the axial direction, and stator channels communicating the first cavity with the second cavity are arranged in at least some winding grooves of a stator iron core of the stator; the rotor is arranged in the rotor cavity; and the motor shaft is inserted into the rotor cavity and supports the rotor, the motor shaft is internally provided with a shaft channel, and the shaft channel is communicated with the first cavity through the end cover channel.

Description

Technical Field

[0001] The present disclosure relates to the field of motor heat dissipation, and more particularly, to a motor and an electric drive system with an improved liquid cooling design. Background Art

[0002] With the rapid development of motors, the power density and lightweight of motors have attracted more and more attention. However, the heat dissipation problem of motors has become the main factor restricting the further improvement of the power density of motors. Taking the common permanent magnet synchronous type motor as an example, the stator winding generates a rotating magnetic field after the alternating current is passed through it. The rotating magnetic field couples with the permanent magnet on the rotor to drive the rotor to rotate. However, at the same time, the rotating magnetic field will generate eddy currents in the rotor core and the stator core, causing the rotor core and the stator core to heat up, while the alternating current will cause the stator winding to heat up. In order to increase the power of the motor, a larger alternating current needs to be passed through the stator winding, but the heat generated by the stator core, stator winding and rotor core will also increase. If this heat cannot be effectively dissipated, it may shorten the service life of the motor or even cause the motor to overheat and burn. Therefore, the overheating problem of the rotor core, stator core and stator winding has become one of the main factors restricting the further improvement of the motor power. To this end, various liquid cooling solutions have emerged in the prior art to help the motor dissipate heat, including placing the stator core in a water jacket, machining cooling liquid channels on the surface and inside of the stator core, etc. However, these liquid cooling solutions all have problems such as poor manufacturing feasibility, uneven heat absorption, and high manufacturing costs to a certain extent.

[0003] Therefore, in this field, there is an urgent need for a technical solution that can help the motor to dissipate heat effectively and has high manufacturing feasibility. Utility Model Content

[0004] In order to solve the above-mentioned problems in the prior art, the present disclosure proposes a motor with an improved liquid cooling design, which includes: a shell, the shell including a shell body and a first end cover and a second end cover connected to the shell body, the first end cover is provided with an end cover channel inside; an isolation cylinder, the isolation cylinder is connected to the first end cover and the second end cover to divide the interior of the shell into a stator cavity and a rotor cavity; a stator arranged in the stator cavity, the stator divides the stator cavity into a first cavity and a second cavity located on both sides thereof along the axial direction, and a stator channel connecting the first cavity with the second cavity is provided in at least some winding slots of its stator core; a rotor arranged in the rotor cavity; and a motor shaft inserted into the rotor cavity and supporting the rotor, the motor shaft is provided with a shaft channel inside, and the shaft channel is connected with the first cavity through the end cover channel.

[0005] According to an optional embodiment of the present disclosure, a stator channel is provided in each winding slot of the stator core.

[0006] According to an optional embodiment of the present disclosure, the stator channel is formed by the gap around the stator winding in the winding slot; and / or, a plurality of wires stacked together are provided in the winding slot, and the stator channel is formed by grooves in one or more wires; and / or, the stator channel extends along an axial path.

[0007] According to an optional embodiment of the present disclosure, the shell is provided with a shell opening leading to the second cavity on its outer surface.

[0008] According to an optional embodiment of the present disclosure, the first end cover is provided with an outer through hole for connecting the first cavity with the end cover channel and an inner through hole for connecting the shaft channel with the end cover channel.

[0009] According to an optional embodiment of the present disclosure, the motor shaft is spaced apart from the first end cover so that a guide channel is formed between the motor shaft and the first end cover, the shaft channel extends from a first opening open toward the guide channel to a second opening open toward the outside of the shell, and the inner through hole leads to the guide channel.

[0010] According to an optional embodiment of the present disclosure, the motor shaft has a first shaft end close to the first end cover and a second shaft end close to the second end cover, wherein the motor shaft extends through the first end cover to position the first shaft end outside the housing; and / or the motor shaft extends through the second end cover to position the second shaft end outside the housing.

[0011] According to an optional embodiment of the present disclosure, the second opening is provided on the second shaft end to be open in the axial direction.

[0012] According to an optional embodiment of the present disclosure, the shaft channel, the guide channel and the inner through hole all have the rotation axis of the motor shaft as their axis; and / or, the shaft channel, the guide channel and the inner through hole all extend along an axial path.

[0013] According to an optional embodiment of the present disclosure, the first end cover is provided with an inner annular flange protruding axially into the rotor cavity, the inner annular flange surrounds the motor shaft, and a sealing ring is provided between the inner annular flange and the motor shaft.

[0014] According to an optional embodiment of the present disclosure, a bearing is further provided between the inner annular flange and the motor shaft.

[0015] According to an optional embodiment of the present disclosure, the sealing ring is located between the bearing and the first end cover in the axial direction.

[0016] According to an optional embodiment of the present disclosure, the motor shaft is axially spaced apart from the first end cover, so that the guide channel is axially located between the motor shaft and the first end cover, and the first opening is axially open.

[0017] According to an optional embodiment of the present disclosure, the shaft channel, the guide channel and the inner through hole are aligned with each other in the axial direction.

[0018] According to an optional embodiment of the present disclosure, the motor shaft is inserted into the inner through hole and radially spaced apart from the first end cover, so that the guide channel is radially located between the motor shaft and the first end cover, and the first opening is radially open.

[0019] According to an optional embodiment of the present disclosure, one end of the motor shaft extends through the first end cover, and the first end cover is provided with an outer annular flange protruding axially to the outside of the housing, the outer annular flange surrounds the motor shaft, and a sealing ring is provided between the outer annular flange and the motor shaft.

[0020] Also in order to solve the problems in the above-mentioned prior art, the present disclosure also proposes an improved electric drive system, which includes: a motor as described in the present disclosure; a gear box, the gear box including a housing and a driving gear accommodated in the housing, the motor shaft of the motor is inserted into the housing, and the driving gear is fixed on the motor shaft, the housing is provided with a drain port near the bottom thereof; and a hydraulic pump, the hydraulic pump having an inlet connected to the drain port and an outlet connected to the second chamber of the motor or the axial channel of the motor shaft.

[0021] According to an optional embodiment of the present disclosure, the motor shaft has a first shaft end close to the first end cover of the motor and a second shaft end close to the second end cover of the motor, the shaft channel extends to the second shaft end, the second shaft end is positioned in the housing, a second opening arranged on the second shaft end is connected to a cavity in the housing, and the outlet of the hydraulic pump is connected to the second cavity.

[0022] According to an optional embodiment of the present disclosure, the motor shaft has a first shaft end close to the first end cover of the motor and a second shaft end close to the second end cover of the motor, the shaft channel extends to the second shaft end, the first shaft end is positioned in the housing, the outlet of the hydraulic pump is connected to the shaft channel via the second shaft end, and the housing is provided with a liquid inlet hole connected to the second cavity.

[0023] According to an optional embodiment of the present disclosure, the housing stores a coolant at the bottom thereof, and the amount of the coolant is set so that a portion of the driving gear is immersed in the coolant.

[0024] The present disclosure may be embodied as the illustrative embodiments in the accompanying drawings. However, it should be noted that the accompanying drawings are only illustrative, and any changes conceived under the teachings of the present disclosure should be considered to be included within the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings illustrate exemplary embodiments of the present disclosure. These drawings should not be interpreted as necessarily limiting the scope of the present disclosure, wherein:

[0026] Figure 1 is a schematic cross-sectional view of a motor according to an embodiment of the present disclosure;

[0027] Figure 2 is a schematic cross-sectional view of a motor according to another embodiment of the present disclosure;

[0028] Figure 3 is a schematic partial cross-sectional view of a stator of a motor according to an embodiment of the present disclosure;

[0029] Figure 4 is a schematic layout diagram of an electric drive system according to an embodiment of the present disclosure; and

[0030] Figure 5 is a schematic layout diagram of an electric drive system according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0031] Further features and advantages of the present disclosure will become more apparent from the following description with reference to the accompanying drawings. Exemplary embodiments of the present disclosure are shown in the accompanying drawings, and the various drawings are not necessarily drawn to actual scale. However, the present disclosure can be implemented in many different forms and should not be interpreted as necessarily being limited to the exemplary embodiments disclosed herein. On the contrary, these exemplary embodiments are merely provided to illustrate the present disclosure and to convey the spirit and essence of the present disclosure to those skilled in the art.

[0032] The present disclosure aims to propose a motor with an improved liquid cooling design. According to the liquid cooling design of the present disclosure, the coolant is allowed to flow through the motor shaft and the stator of the motor in sequence, so that the coolant can absorb the heat of the rotor core when flowing in the motor shaft, and absorb the heat of the stator core and the stator winding when flowing in the stator, thereby improving the heat dissipation of the rotor core, the stator core and the stator winding. In particular, the liquid cooling design according to the present disclosure also allows the coolant to flow in the winding slots of the stator core, so that the coolant can directly contact the stator winding in the winding slots, thereby further improving the heat dissipation of the stator winding. In particular, the liquid cooling design according to the present disclosure can also avoid the coolant from contacting the rotor core, thereby avoiding the coolant from increasing the rotational resistance of the rotor core, thereby maintaining the efficiency of the motor while improving the heat dissipation. In particular, the liquid cooling design according to the present disclosure also allows the coolant to flow through the motor shaft and the stator with a lower hydraulic pressure, thereby reducing the requirements for supporting facilities such as hydraulic pumps to reduce the manufacturing cost of the cooling design according to the present disclosure, and reducing the risk of leakage of the coolant. In addition, the liquid cooling design according to the present disclosure has a relatively simple structure and therefore has a higher manufacturing feasibility, thereby being able to help the motor to achieve effective heat dissipation without significantly increasing the cost of the motor.

[0033] Various optional but non-limiting embodiments of the motor according to the present disclosure are described in detail below with reference to various drawings. As used herein, the term "axial" refers to a direction parallel to or coincident with the rotation axis of the motor, "radial" refers to a direction perpendicular to the rotation axis of the motor, and "circumferential" refers to a direction around the rotation axis of the motor. These and other terms indicating orientations are merely intended to more intuitively illustrate the teachings of the present disclosure in conjunction with the drawings, and should not be interpreted in any way as limiting the scope of protection of the present disclosure.

[0034] refer to Figure 1 and Figure 2 ,in, Figure 1 shows a schematic cross-sectional view of a motor according to an embodiment of the present disclosure, Figure 2 Schematic cross-sectional view of a motor according to another embodiment of the present disclosure is shown. Figure 1 and Figure 2As shown, the motor 10 includes a housing 100, which includes a housing body 110 that is generally annular, and a first end cover 120 and a second end cover 130 that are respectively connected to two ends of the housing body 110 that are separated along the axial direction XX', wherein the housing body 110, the first end cover 120 and the second end cover 130 together define an inner cavity 140 located inside the housing 100. In other words, the housing body 110 defines the inner cavity 140 on the inside, and the first end cover 120 and the second end cover 130 are respectively connected to two ends of the housing body 110 that are separated along the axial direction XX', so as to close the inner cavity 140. The motor 10 also includes an isolation cylinder 200 disposed in the inner cavity 140 of the casing 100, the isolation cylinder 200 is arranged around the axial direction XX', that is, oriented along the axial direction XX', and the two ends of the isolation cylinder 200 separated along the axial direction XX' are respectively connected to the first end cover 120 and the second end cover 130, so that the inner cavity 140 of the casing 100 is divided by the isolation cylinder 200 into a generally annular stator cavity 141 and a generally cylindrical rotor cavity 142, wherein the stator cavity 141 is located radially outside the isolation cylinder 200, the rotor cavity 142 is located radially inside the isolation cylinder 200, and the stator cavity 141 and the rotor cavity 142 are isolated from each other by the isolation cylinder 200.

[0035] Continue to refer Figure 1 and Figure 2The motor 10 further includes a stator 300 disposed in a stator cavity 141, a rotor 400 disposed in a rotor cavity 142, and a motor shaft 500 inserted into the rotor cavity 142. The stator 300 includes a stator core 310 and a stator winding 320 disposed on the stator core 310, wherein the stator core 310 is provided with a plurality of winding slots 311 distributed along a circumferential direction on its radial inner side, wherein each winding slot 311 extends through the stator core 310 along an axial direction XX' and is provided for inserting a portion of the conductor of the stator winding 320, so as to fix the stator winding 320 on the stator core 310. In addition, the stator core 310 is connected to the isolation tube 200 on its radial inner side and to the shell body 110 on its radial outer side, so that the stator cavity 141 is divided by the stator core 310 into a first cavity 141a and a second cavity 141b located on both sides thereof along the axial direction XX' (i.e., located on both axial sides of the stator core 310), wherein the first cavity 141a and the second cavity 141b are also generally annular, and the first cavity 141a is adjacent to the first end cover 120, so that the first cavity 141a is closed by the second end cover 120 or is partially defined by the first end cover 120, and the second cavity 141b is adjacent to the second end cover 130, so that the second cavity 141b is closed by the first end cover 130 or is partially defined by the second end cover 130. The rotor 400 is fixed to (more generally, non-rotatably connected to) the motor shaft 500, and the motor shaft 500 is rotatably supported in the rotor cavity 142, for example, by a bearing, so that the rotor 400 is rotatably supported in the rotor cavity 142 by the motor shaft 500. In the case where the motor 10 is configured as a permanent magnet synchronous motor, the rotor 400 includes a rotor core 410 fixed to the motor shaft 500 and a permanent magnet 420 fixed to the rotor core 410. Of course, the motor 10 can also be configured as an asynchronous induction motor, so that the rotor 400 includes a stator core 410 and an armature winding fixed to the stator core 410. Therefore, the specific type of the motor 10 cannot constitute a limitation on the scope of protection of the present disclosure.

[0036] Taking the permanent magnet synchronous type motor 10 as an example, during its operation, the stator winding 320 is passed with alternating current, thereby generating a rotating magnetic field, which is coupled with the permanent magnet 420 under the guidance of the stator core 310, thereby driving the permanent magnet 420 to rotate, and the permanent magnet 420 further drives the motor shaft 500 to rotate through the rotor core 410, so that the motor shaft 500 can transmit power to the outside of the motor 10. However, as a byproduct of power, the rotating magnetic field will cause eddy currents to be generated in the stator core 310 and the rotor core 410, and the eddy currents will generate heat in the stator core 310 and the rotor core 410, and at the same time, the alternating current will generate heat in the stator winding 320.

[0037] In order to dissipate the heat in the stator core 310, the stator winding 320 and the rotor core 410, the present disclosure proposes the following liquid cooling design. Figure 1 and Figure 2 As shown, at least some of the plurality of winding slots 311 of the stator core 310 are formed with stator channels 330 for the coolant to flow through, wherein each stator channel 330 extends through the stator core 310 along the axial direction XX', thereby fluidly connecting the first cavity 141a with the second cavity 141b. In this configuration, since the first cavity 141a and the second cavity 141b are isolated from each other by the stator core 310 located therebetween, the first cavity 141a and the second cavity 141b are fluidly connected to each other only through the stator channels 330 formed in the winding slots 311, so that the coolant must pass through the stator channels 330 to flow between the first cavity 141a and the second cavity 141b, and when the coolant flows in the stator channels 330, the coolant can directly contact the winding slots 311. 1, so that the heat of the stator winding 320 can be directly absorbed in the winding slot 311, thereby realizing the in-slot direct cooling of the stator winding 320 in the winding slot 311, and the coolant collected in the first cavity 141a and the second cavity 141b can also directly contact the entire axial end of the stator core 310, thereby directly absorbing the heat of the stator core 310 in the first cavity 141a and the second cavity 141b, thereby realizing the in-slot direct cooling of the stator core 310. In particular, a stator channel 330 is formed in each winding slot 311 of the stator core 310, thereby realizing the in-slot direct cooling of the stator winding 320 in each winding slot 311. In particular, the stator channel 330 can be formed by the gap around the stator winding 320 in the winding slot 311. In particular, when the stator winding 320 is composed of flat wires so that the motor 10 is configured as a flat wire motor, a plurality of flat wires are stacked in each winding slot 311, and the stator channel 330 can be formed by grooves formed in one or more flat wires, and the grooves extend along the length direction of the flat wires to form the stator channel 330 that runs through the stator winding 320. The profile of the cross section of the groove along the cross section perpendicular to the length direction of the flat wires can be a part of a circle, an ellipse, a rectangle, a triangle, etc. In one embodiment, as Figure 3 As shown, it shows the Figure 1 and Figure 2A schematic partial cross-sectional view of the stator 300 of the motor 10 taken along line AA in FIG. 2 , wherein a plurality of flat wires 321 are stacked in a radial direction, and a groove 322 may be provided in each flat wire 321. In one embodiment, the entire outer surface of the flat wire 321 has an insulating layer, wherein the thickness of the insulating layer at the groove 322 is the same as or different from the thickness of the insulating layer at other portions of the flat wire 321 except the groove 322. In another embodiment, the outer surface of the flat wire 321 except the groove 322 has an insulating layer, and the inner surface of the groove 322 is at least partially exposed (i.e., there is no insulating layer, exposing the metal conductor in the flat wire), the portion of the flat wire 321 opposite to the groove 322 of the adjacent flat wire 321 is at least partially exposed, and the distance between the exposed portions is set to provide insulation performance. In some embodiments, the groove 322 can be set at one or more of the following positions: between adjacent flat wires 321, between the flat wire 321 and the inner surface of the winding groove 311, and at the corner of the profile of the cross section of the flat wire 321 perpendicular to its length direction. Figure 3 The groove 322 in the illustrated embodiment is disposed on the upper surface of each flat conductive wire 321 . In other embodiments, the groove 322 may also be disposed on the lower surface of each flat conductive wire 321 .

[0038] In addition, the housing 100 is provided with a housing opening 101 on its outer surface, the housing opening 101 leads to the second chamber 141b through a through hole in the housing 100 or is in fluid communication with the second chamber 141b, and the housing opening 101 is configured to allow coolant to enter and exit the second chamber 141b. In this configuration, the second chamber 141b can receive coolant from the outside of the motor 10 through the housing opening 101, and can also discharge the coolant inside itself to the outside of the motor 10 through the housing opening 101. In particular, the housing opening 101 is provided on the outer surface of the housing body 110. Of course, in an embodiment not shown, the housing opening 101 can also be provided on the outer surface of the second end cover 130.

[0039] The first end cover 120 has a hollow structure. Specifically, the first end cover 120 defines or forms an end cover channel 121 for the coolant to flow through, and the first end cover 120 is also provided with an outer through hole 122 and an inner through hole 123 that are connected to or lead to the end cover channel 121. In addition, the first end cover 120 is also positioned so that the outer through hole 122 is located radially outside the separation cylinder 200, and the number of the outer through hole 122 can be one or more, and the inner through hole 123 is located radially inside the separation cylinder 200. Under this configuration, the coolant can flow from one of the outer through hole 122 and the inner through hole 123 into the end cover channel 121, and then be discharged from the end cover channel 121 through the other of the outer through hole 122 and the inner through hole 123, and when the coolant flows in the end cover channel 121, the coolant can exchange heat with the outside through the outer surface of the first end cover 120 to reduce the temperature, thereby improving its cooling effect. In particular, since the outer through hole 122 is positioned radially outside the isolation tube 200 , the outer through hole 122 constitutes a channel that connects the first cavity 141 a with the end cover channel 121 so that the coolant can flow between the first cavity 141 a and the end cover channel 121 through the outer through hole 122 .

[0040] The motor shaft 500 also has a hollow structure. Specifically, the motor shaft 500 defines or forms a shaft channel 510 for the coolant to flow therethrough, and the shaft channel 510 extends from a first opening 520 provided on the outer surface of the motor shaft 500 to a second opening 530 also provided on the outer surface of the motor shaft 500, wherein the first opening 520 is close to the first end cover 120, and the second opening 530 is close to the second end cover 130. In this configuration, the coolant can flow from one of the first opening 520 and the second opening 530 into the shaft channel 510, and then be discharged from the shaft channel 510 through the other of the first opening 520 and the second opening 530, and when the coolant flows in the shaft channel 510, the coolant can absorb the heat of the rotor 400 (more specifically, the rotor core 410) through the motor shaft 500, thereby achieving effective heat dissipation of the rotor 400. In addition, the motor shaft 500 extends through the second end cover 130 so that the second opening 530 is open to the outside of the housing 100. In this configuration, the shaft channel 510 can receive the coolant from the outside of the motor 10 through the second opening 530, and can also discharge the coolant inside itself to the outside of the motor 10 through the second opening 530. In particular, the second opening 530 is positioned outside the housing 100. In particular, the second opening 530 is provided on the axial end of the motor shaft 500 so that the second opening 530 is open toward the axial direction XX'.

[0041] A guide channel 610 is formed between the motor shaft 500 and the first end cover 120, wherein the first opening 520 of the motor shaft 500 is open toward the guide channel 610, and the guide channel 610 is in fluid communication with the inner through hole 123 of the first end cover 120, thereby enabling the guide channel 610 to fluidly communicate the first opening 520 of the motor shaft 500 with the inner through hole 123 of the first end cover 120, and thus to fluidly communicate the shaft channel 510 of the motor shaft 500 with the end cover channel 121 of the first end cover 120. Under this configuration, on the one hand, the coolant can flow between the shaft channel 510 of the motor shaft 500 and the end cover channel 121 of the first end cover 120 through the guide channel 610; on the other hand, the guide channel 610 separates the motor shaft 500 from the first end cover 120, thereby preventing the motor shaft 500 from wearing against the first end cover 120 during rotation. In particular, the shaft channel 510, the guide channel 610 and the inner through hole 123 are all coaxially arranged with the rotation axis of the motor shaft 500 as the axis, and extend along a straight axial path. Under this configuration, the coolant can flow more smoothly through the shaft channel 510, the guide channel 610 and the inner through hole 123, thereby further improving the heat dissipation effect, and making it sufficient to drive the coolant flow with a lower hydraulic pressure, thereby reducing the parameter requirements for auxiliary facilities such as hydraulic pumps, thereby reducing the cost required to equip the motor with liquid cooling facilities, and also reducing the risk of coolant leakage.

[0042] Under the configuration of the liquid cooling design described above, the second cavity 141b, the stator channel 330, the first cavity 141a, the end cover channel 121, the guide channel 610 and the shaft channel 510 together form a complete flow path from the housing opening 101 to the second opening 530. When the housing opening 101 is used as a liquid inlet and the second opening 530 is used as a liquid outlet, the coolant can flow from the housing opening 101 to the second opening 530 along the flow path; conversely, when the housing opening 101 is used as a liquid outlet and the second opening 530 is used as a liquid inlet, the coolant can flow from the second opening 530 to the housing opening 101 along the flow path. Regardless of the situation, when the coolant flows along the flow path, the coolant can cool the stator core 310, the stator winding 320 and the rotor core 410 in turn, thereby effectively solving the heat dissipation problem of the stator core 310, the stator winding 320 and the rotor core 410. The solution to the heat dissipation problem of the three provides the possibility of further improving the power of the motor 10.

[0043] In particular, if Figure 1 and Figure 2As shown, the first end cover 120 is further provided with an inner annular flange 124 protruding along the axial direction XX', wherein the inner annular flange 124 protrudes into the rotor cavity 142. In addition, the inner annular flange 124 surrounds the inner through hole 123 and the motor shaft 500 along the circumferential direction, so that the inner through hole 123, the motor shaft 500 and the guide channel 610 are all located radially inside the inner annular flange 124, and further the guide channel 610 connects the first opening 520 with the inner through hole 123 fluid at the radial inside of the inner annular flange 124. In addition, the first end cover 120 is also provided with a sealing ring 125 located between the inner annular flange 124 and the motor shaft 500. The sealing ring 125 can be made of a wear-resistant material such as polytetrafluoroethylene, for example, and can be clamped between the radial inner surface of the inner annular flange 124 and the radial outer surface of the motor shaft 500, so that the sealing ring 125 can seal the guide channel 610 relative to the rotor cavity 142, that is, the sealing ring 125 can isolate the guide channel 610 and the rotor cavity 142 from each other. In this configuration, the sealing ring 125 is located between the inner annular flange 124 and the motor shaft 500 in the radial direction, and between the guide channel 610 and the rotor cavity 142 in the axial direction XX', so the coolant from the end cover channel 121 can only flow into the shaft channel 510 through the guide channel 610, and will not leak into the rotor cavity 142, and the coolant from the shaft channel 510 can also only flow into the end cover channel 121 through the guide channel 610, and will not leak into the rotor cavity 142. In short, the sealing ring 125 can prevent the coolant from entering the rotor cavity 142, thereby preventing the coolant from increasing the rotation resistance of the rotor 400, so that the working efficiency of the motor 10 can be maintained while solving the heat dissipation problem. In particular, the first end cover 120 is further provided with a bearing 126 located between the inner annular flange 124 and the motor shaft 500, the outer ring of the bearing 126 is connected to the radial inner surface of the inner annular flange 124, and the inner ring thereof is connected to the radial outer surface of the motor shaft 500, so that the inner annular flange 124 can rotatably support the motor shaft 500 through the bearing 126. In this configuration, the inner annular flange 124 is not only used to accommodate the sealing ring 125 that seals the guide channel 610, but also used to accommodate the bearing 126 that supports the motor shaft 500, and the bearing 126 can also play a role in sealing (such as dynamic sealing) the guide channel 610 to a certain extent. In particular, the sealing ring 125 is located between the bearing 126 and the first end cover 120 in the axial direction XX', so that the sealing ring 125 can prevent the coolant from contacting the bearing 126.

[0044] In particular, similar to the first end cover 120, the second end cover 130 may also be provided with an inner annular flange 131 protruding along the axial direction XX', wherein the inner annular flange 131 protrudes into the rotor cavity 142. In addition, the inner annular flange 131 surrounds the motor shaft 500 along the circumferential direction, so that the motor shaft 500 is located radially inside the inner annular flange 131. In addition, the second end cover 130 is further provided with a bearing 132 located between the inner annular flange 131 and the motor shaft 500, the outer ring of the bearing 132 is connected to the radial inner surface of the inner annular flange 131, and the inner ring thereof is connected to the radial outer surface of the motor shaft 500, so that the inner annular flange 131 can rotatably support the motor shaft 500 through the bearing 132.

[0045] The above is based on Figure 1 and Figure 2 The general configuration of the liquid cooling design of the electric machine according to the present disclosure is described. Figure 1 and Figure 2 The embodiments shown are substantially the same in this general configuration, but they still differ in other aspects. Figure 1In the illustrated embodiment, the first opening 520 is disposed on an axial end (hereinafter referred to as the first axial end or the first axial end) 501 of the motor shaft 500 that is close to the first end cover 120, so that the first opening 520 is open toward the axial direction XX', and the first axial end 501 is spaced apart from the first end cover 120 along the axial direction XX', so that the guide channel 610 is located between the first axial end 501 and the first end cover 120 along the axial direction XX'. In this case, the guide channel 610 is a cylindrical channel located between the motor shaft 500 and the first end cover 120. In addition, the second opening 530 is provided on the axial end portion (hereinafter referred to as the second axial end portion or the second axial end) 502 of the motor shaft 500 close to the second end cover 130, so that the shaft channel 510 extends from the first axial end portion 501 of the motor shaft 500 to the second axial end portion 502 along the axial direction XX', that is, the shaft channel 510 extends through the motor shaft 500 over the entire axial length of the motor shaft 500, which helps to reduce the pressure loss of the coolant in the shaft channel 510, thereby allowing the coolant to flow more quickly in the shaft channel 510, thereby further improving the heat dissipation effect. In addition, the motor shaft 500 extends through the second end cover 130, so that the second axial end portion 502 is positioned outside the housing 100, so that the second axial end portion 502 can be used as the driving end of the motor shaft 500, for example, a driving gear for driving a driven gear can be assembled on the motor shaft 500 through the second axial end portion 502. In particular, the shaft channel 510, the guide channel 610 and the inner through hole 123 are aligned or aligned with each other along the axial direction XX', thereby reducing the pressure loss of the coolant in the guide channel 610, thereby allowing the coolant to flow more quickly in the guide channel 610 to further improve the heat dissipation effect.

[0046] It is also worth mentioning that in Figure 1In the illustrated embodiment, the housing opening 101 can be used as a liquid inlet, and the second opening 530 can be used as a liquid outlet, so as to cool the stator 300 first and then the rotor 400. In this case, the coolant from the outside of the housing 100 can enter the second cavity 141b through the housing opening 101 and be collected in the second cavity 141b, the coolant in the second cavity 141b then flows to the first cavity 141a through each stator channel 330 and is collected in the first cavity 141a, the coolant in the first cavity 141a then enters the end cover channel 121 through each outer through hole 122, and then is discharged from the end cover channel 121 through the inner through hole 123, the coolant discharged from the inner through hole 123 is then guided to the first opening 520 by the guide channel 610 and enters the shaft channel 510, and finally the coolant in the shaft channel 510 is discharged to the outside of the housing 100 through the second opening 530. In this configuration, the coolant can not only cool the stator 300 and the rotor 400 in the stator channel 330 and the shaft channel 510 in sequence, but also the coolant heated by the stator 300 can dissipate heat to the external environment through the outer surface of the first end cover 120 in the end cover channel 121, thereby cooling the coolant before entering the shaft channel 510, and thus improving the cooling effect of the rotor 400. In particular, a plurality of fins 128 can be provided on the outer surface of the first end cover 120 to increase the heat exchange area with the external environment, thereby further improving the cooling effect of the rotor 400. Of course, the above embodiment is only exemplary. In an alternative embodiment, the housing opening 101 can be used as a drain port, and the second opening 530 can be used as a liquid inlet, so that the coolant flows in the opposite direction to the above, thereby cooling the rotor 400 first and then cooling the stator 300.

[0047] In particular, Figure 2In the illustrated embodiment, the first opening 520 is provided on the radial outer surface of the motor shaft 500 so that the first opening 520 is open in the radial direction. The inner through hole 123 extends through the first end cover 120, the motor shaft 500 is inserted into the inner through hole 123, and thus extends through the first end cover 120 through the inner through hole 123, and the motor shaft 500 is spaced apart from the first end cover 120 in the radial direction so that the guide channel 610 is located between the motor shaft 500 and the first end cover 120 in the radial direction, in which case the guide channel 610 is an annular channel surrounding the motor shaft 500. In addition, since the motor shaft 500 extends through the first end cover 120, the first axial end 501 of the motor shaft 500 is also positioned outside the housing 100, which allows the first axial end 501 to be used as the driving end of the motor shaft 500, for example, a driving gear for driving a driven gear can be assembled on the motor shaft 500 through the first axial end 501. In particular, the first end cover 120 is also provided with an outer annular flange 127 protruding toward the outside of the shell 100 along the axial direction XX', and the outer annular flange 127 surrounds the inner through hole 123 and the motor shaft 500 along the circumferential direction, so that the inner through hole 123, the motor shaft 500 and the guide channel 610 are all located radially inside the outer annular flange 127, and the first end cover 120 is also provided with a sealing ring 125 located between the outer annular flange 127 and the motor shaft 500, and the sealing ring 125 can be made of a wear-resistant material such as polytetrafluoroethylene, for example, and can be clamped between the inner surface of the outer annular flange 127 and the outer surface of the motor shaft 500, so that the sealing ring 125 can seal the guide channel 610 relative to the outside of the shell 100, that is, the sealing ring 125 can isolate the guide channel 610 from the outside of the shell 100. In this configuration, the sealing ring 125 is located between the outer annular flange 127 and the motor shaft 500 in the radial direction, and between the guide channel 610 and the outside of the housing 100 in the axial direction XX', so the coolant from the end cover channel 121 can only flow into the shaft channel 510 through the guide channel 610 without leaking to the outside of the housing 100, and the coolant from the shaft channel 510 can also only flow into the end cover channel 121 through the guide channel 610 without leaking to the outside of the housing 100. In short, the sealing ring 125 can prevent the coolant from leaking to the outside of the housing 100, thereby preventing the coolant from contaminating or damaging other devices and facilities outside the housing 100. In particular, the first end cover 120 is also provided with a bearing 126 located between the outer annular flange 127 and the motor shaft 500, the outer ring of the bearing 126 is connected to the inner surface of the outer annular flange 127, and its inner ring is connected to the outer surface of the motor shaft 500, so that the outer annular flange 127 can rotatably support the motor shaft 500 through the bearing 126.In this configuration, the outer annular flange 127 is used not only to accommodate the sealing ring 125 that seals the guide channel 610, but also to accommodate the bearing 126 that supports the motor shaft 500, and the bearing 126 can also play a role in sealing (such as dynamic sealing) the guide channel 610 to a certain extent. In particular, the bearing 126 is located outside the sealing ring 125 in the axial direction XX', so that the sealing ring 125 can prevent the coolant from contacting the bearing 126.

[0048] It is also worth mentioning that in Figure 2 In the illustrated embodiment, the second opening 530 may be used as a liquid inlet, and the housing opening 101 may be used as a liquid outlet, so as to cool the rotor 400 first and then the stator 300 . In this case, since the motor shaft 500 extends through the second end cover 130 so that the second axial end 502 and the second opening 530 are positioned outside the housing 100, the coolant from outside the housing 100 can smoothly enter the shaft channel 510 through the second opening 530, and then be discharged from the shaft channel 510 through the first opening 520. The coolant discharged from the first opening 520 is then guided to the inner through hole 123 by the guide channel 610, and then enters the end cover channel 121 through the inner through hole 123. The coolant in the end cover channel 121 then enters the first cavity 141a through the outer through hole 122 and is collected in the first cavity 141a. The coolant in the first cavity 141a then flows to the second cavity 141b through each stator channel 330 and is collected in the second cavity 141b. Finally, the coolant in the second cavity 141b is discharged to the outside of the housing 100 through the housing opening 101. In this configuration, the coolant can not only cool the rotor 400 and the stator 300 in the shaft channel 510 and the stator channel 330 in sequence, but also the coolant heated by the rotor 400 can dissipate heat to the external environment through the outer surface of the first end cover 120 in the end cover channel 121, thereby cooling the coolant before entering the stator channel 330, and thus improving the cooling effect of the stator 300. In particular, a plurality of fins 128 can be provided on the outer surface of the first end cover 120 to increase the heat exchange area with the external environment, thereby further improving the cooling effect of the stator 300. Of course, the above embodiment is only exemplary. In an alternative embodiment, the housing opening 101 can be used as a liquid inlet, and the second opening 530 can be used as a liquid outlet, so that the coolant flows in the opposite direction to the above, so as to first cool the stator 300 and then cool the rotor 400. Of course, in an embodiment where the second axial end 502 of the motor shaft 500 is not used as a driving end, the second axial end 502 may not protrude from the second end cover 130, as long as the second opening 530 can communicate coolant with the outside.

[0049] The above is based on Figure 1 and Figure 2An electric machine with an improved liquid cooling design according to the present disclosure is described. In addition to the electric machine, the present disclosure also proposes an electric drive system with an improved liquid cooling design. Figure 4 and Figure 5 ,in, Figure 4 shows a schematic layout diagram of an electric drive system according to an embodiment of the present disclosure, Figure 5 A schematic layout diagram of an electric drive system according to another embodiment of the present disclosure is shown.

[0050] like Figure 4 As shown, the electric drive system generally includes Figure 1 The motor 10, the gearbox 20 and the hydraulic pump 30 of the illustrated embodiment are configured. The gearbox 20 generally includes a housing 201, a driving gear 202 and a driven gear 203 accommodated in the housing 201, and an output shaft 204 extending through the housing 201, wherein the driven gear 203 is meshed with the driving gear 202 and is fixed on the output shaft 204. The motor shaft 500 of the motor 10 extends through the housing 201 so that the second axial end 502 and the second opening 530 of the motor shaft 500 are positioned in the housing 201, and the driving gear 202 is fixed on the motor shaft 500 so that the motor shaft 500 can drive the output shaft 204 to rotate through the driving gear 202 and the driven gear 203. In particular, the housing 201 is also provided with a drain port 205 near its bottom, and the drain port 205 is in fluid communication with the inlet of the hydraulic pump 30, and the outlet of the hydraulic pump 30 is in fluid communication with the housing opening 101 of the motor 10. During the operation of the electric drive system, the motor shaft 500 of the motor 10 drives the output shaft 204 to rotate through the driving gear 202 and the driven gear 203 of the gearbox 20, and at the same time, the hydraulic pump 30 extracts the coolant collected at the bottom of the housing 201 of the gearbox 20 through the drain port 205 of the gearbox 20, and then injects the coolant into the housing 100 of the motor 10 through the housing opening 101 of the motor 10. The coolant injected into the housing 100 of the motor 10 then flows from the housing opening 101 to the second opening 530 along the flow path described above, so as to cool the stator and rotor of the motor 10 in turn, and then the coolant is discharged from the second opening 530 into the housing 201 of the gearbox 20 and collected at the bottom of the housing 201, thereby realizing the circulation of the coolant between the gearbox 20 and the motor 10. Under this configuration, the gearbox 201 provides a heat dissipation place for the coolant, thereby improving the heat dissipation effect of the motor 10. In particular, the amount of coolant in the electric drive system can be set so that the coolant collected at the bottom of the housing 201 is sufficient to immerse a portion of the driving gear 202 or the driven gear 203. In this configuration, the coolant can not only improve the heat dissipation of the motor 10, but also lubricate various components in the gearbox 20 (e.g., the driving gear 202 and the driven gear 203).

[0051] Figure 5 The embodiment shown is Figure 4 The embodiment shown differs in that the motor 10 is arranged in accordance with Figure 2 The embodiment shown is configured, and the motor shaft 500 of the motor 10 extends through the housing 201 so that the first axial end 501 of the motor shaft 500 is positioned in the housing 201. In addition, the housing 201 is further provided with a liquid inlet 206 near the top thereof, wherein the liquid inlet 206 is in fluid communication with the housing opening 101 of the motor 10, and the outlet of the hydraulic pump 30 is in fluid communication with the second opening 530 of the motor shaft 500. During the operation of the electric drive system, the motor shaft 500 of the motor 10 drives the output shaft 204 to rotate through the driving gear 202 and the driven gear 203 of the gear box 20, and at the same time, the hydraulic pump 30 extracts the coolant collected at the bottom of the housing 201 of the gear box 20 through the drain port 205 of the gear box 20, and then injects the coolant into the shaft channel 510 through the second opening 530 of the motor shaft 500. The coolant injected into the shaft channel 510 then flows from the second opening 530 to the housing opening 101 along the flow path described above, so as to cool the rotor and stator of the motor 10 in turn, and then the coolant is discharged from the housing opening 101 and transported to the liquid inlet 206, and then the coolant enters the housing 201 of the gear box 20 through the liquid inlet 206 and is collected at the bottom of the housing 201, thereby realizing the circulation of the coolant between the gear box 20 and the motor 10. Under this configuration, the gear box 201 also provides a heat dissipation place for the coolant, thereby improving the heat dissipation effect of the motor 10. In addition, the amount of coolant in the electric drive system can also be set so that the coolant collected at the bottom of the housing 201 is sufficient to immerse a portion of the driving gear 202 or the driven gear 203, so as to lubricate the various components in the gearbox 20 while improving the heat dissipation of the motor 10.

[0052] The above describes in detail the optional but non-limiting embodiments of the motor and electric drive system according to the present disclosure with the aid of the accompanying drawings. For those of ordinary skill in the art, without departing from the spirit and substance of the present disclosure, modifications and supplements to the technology and structure and the re-combination of the features in each embodiment should obviously be considered to be included in the scope of the present disclosure. Therefore, these modifications and supplements that can be conceived under the teachings of the present disclosure should be considered as part of the present disclosure. The scope of the present disclosure includes equivalent technologies known at the filing date of the present disclosure and equivalent technologies that have not yet been foreseen.

Claims

1. A motor, characterized in that include: A housing (100), the housing (100) comprising a housing body (110) and a first end cover (120) and a second end cover (130) connected to the housing body (110), wherein the first end cover (120) is provided with an end cover channel (121) inside; An isolating cylinder (200), the isolating cylinder (200) being connected to the first end cover (120) and the second end cover (130) so as to separate the interior of the housing (100) into a stator cavity (141) and a rotor cavity (142); A stator (300) disposed in the stator cavity (141), the stator (300) dividing the stator cavity (141) into a first cavity (141a) and a second cavity (141b) located on both sides thereof in the axial direction, and a stator channel (330) for connecting the first cavity (141a) and the second cavity (141b) is provided in at least some winding slots (311) of the stator core (310); A rotor (400) disposed in the rotor cavity (142); as well as A motor shaft (500) is inserted into the rotor cavity (142) and supports the rotor (400), wherein the motor shaft (500) is provided with a shaft channel (510) inside, and the shaft channel (510) is communicated with the first cavity (141a) through the end cover channel (121).

2. The motor according to claim 1, characterized in that A stator channel (330) is provided in each winding slot (311) of the stator core (310).

3. The motor according to claim 1, characterized in that The stator channel (330) is formed by a gap around the stator winding (320) in the winding slot (311); and / or, a plurality of wires stacked together are provided in the winding slot (311), and the stator channel (330) is formed by grooves in one or more wires; and / or, the stator channel (330) extends along an axial path.

4. The motor according to claim 1, characterized in that The housing (100) is provided on its outer surface with a housing opening (101) leading to the second chamber (141b).

5. The motor according to any one of claims 1 to 4, characterized in that: The first end cover (120) is provided with an outer through hole (122) for connecting the first cavity (141a) with the end cover channel (121), and an inner through hole (123) for connecting the shaft channel (510) with the end cover channel (121).

6. The motor according to claim 5, characterized in that The motor shaft (500) is spaced apart from the first end cover (120) so that a guide channel (610) is formed between the motor shaft (500) and the first end cover (120), the shaft channel (510) extending from a first opening (520) open toward the guide channel (610) to a second opening (530) open toward the outside of the housing (100), and the inner through hole (123) leads to the guide channel (610).

7. The motor according to claim 6, characterized in that The motor shaft (500) has a first shaft end (501) close to the first end cover (120) and a second shaft end (502) close to the second end cover (130), wherein: The motor shaft (500) extends through the first end cover (120) to position the first shaft end (501) outside the housing (100); and / or The motor shaft (500) extends through the second end cover (130) to position the second shaft end (502) outside the housing (100).

8. The motor according to claim 7, characterized in that The second opening (530) is provided on the second shaft end (502) to be open in the axial direction.

9. The motor according to claim 6, characterized in that The shaft channel (510), the guide channel (610) and the inner through hole (123) all have the rotation axis of the motor shaft (500) as their axis; and / or the shaft channel (510), the guide channel (610) and the inner through hole (123) all extend along an axial path.

10. The motor according to claim 6, characterized in that The first end cover (120) is provided with an inner annular flange (124) protruding axially into the rotor cavity (142), the inner annular flange (124) surrounds the motor shaft (500), and a sealing ring (125) is provided between the inner annular flange (124) and the motor shaft (500).

11. The motor according to claim 10, characterized in that A bearing (126) is also provided between the inner annular flange (124) and the motor shaft (500).

12. The motor according to claim 11, characterized in that The sealing ring (125) is located between the bearing (126) and the first end cover (120) in the axial direction.

13. The motor according to claim 6, characterized in that The motor shaft (500) is spaced apart from the first end cover (120) in the axial direction, so that the guide channel (610) is located between the motor shaft (500) and the first end cover (120) in the axial direction, and the first opening (520) is open in the axial direction.

14. The motor according to claim 13, characterized in that The shaft passage (510), the guide passage (610), and the inner through hole (123) are aligned with each other in the axial direction.

15. The motor according to claim 6, characterized in that The motor shaft (500) is inserted into the inner through hole (123) and is radially spaced apart from the first end cover (120), so that the guide channel (610) is radially located between the motor shaft (500) and the first end cover (120), and the first opening (520) is radially open.

16. The motor according to claim 15, characterized in that One end of the motor shaft (500) extends through the first end cover (120), and the first end cover (120) is provided with an outer annular flange (127) protruding axially to the outside of the housing (100), the outer annular flange (127) surrounds the motor shaft (500), and a sealing ring (125) is provided between the outer annular flange (127) and the motor shaft (500).

17. An electric drive system, characterized in that: include: The motor according to any one of claims 1 to 16; A gear box (20), the gear box (20) comprising a housing (201) and a driving gear (202) accommodated in the housing (201), a motor shaft (500) of the motor being inserted into the housing (201), and the driving gear (202) being fixed on the motor shaft (500), and the housing (201) being provided with a drain port (205) near the bottom thereof; as well as A hydraulic pump (30) having an inlet communicating with the discharge port (205) and an outlet communicating with the second chamber (141b) of the motor or the shaft passage (510) of the motor shaft (500).

18. The electric drive system according to claim 17, characterized in that: The motor shaft (500) has a first shaft end (501) close to the first end cover (120) of the motor and a second shaft end (502) close to the second end cover (130) of the motor, the shaft channel (510) extends to the second shaft end (502), the second shaft end (502) is positioned in the housing (201), a second opening (530) arranged on the second shaft end (502) is connected to a cavity in the housing (201), and an outlet of the hydraulic pump (30) is connected to the second cavity (141b).

19. The electric drive system according to claim 17, characterized in that: The motor shaft (500) has a first shaft end (501) close to the first end cover (120) of the motor and a second shaft end (502) close to the second end cover (130) of the motor, the shaft channel (510) extends to the second shaft end (502), the first shaft end (501) is positioned in the housing (201), the outlet of the hydraulic pump (30) is connected to the shaft channel (510) via the second shaft end (502), and the housing (201) is provided with a liquid inlet hole (206) connected to the second chamber (141b).

20. The electric drive system according to any one of claims 17 to 19, characterized in that: The housing (201) stores cooling liquid at the bottom thereof, and the amount of the cooling liquid is set so that a portion of the driving gear (202) is immersed in the cooling liquid.

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