CN220087100U - Driving device integrated with speed reducing mechanism - Google Patents

Abstract

The utility model provides a driving device integrating a speed reducing mechanism, which comprises a shell, wherein the shell comprises a separation shell, one side of the separation shell is provided with the speed reducing mechanism, the other side of the separation shell is provided with the driving mechanism, and a first cooling structure is arranged in the shell wall of the separation shell. Through set up first cooling structure in separating the shell to realize separating shell one side actuating mechanism cooling, can also separate the reduction gears of shell opposite side and cool off, effectively prevent that the heat that actuating mechanism produced from transmitting for reduction gears to reduction gears and actuating mechanism share one separates the shell, further reduced whole actuating device's axial size, weight is alleviateed, the volume is reduced, has improved actuating device's integrality.

Description

Driving device integrated with speed reducing mechanism

Technical Field

The utility model relates to the technical field of driving motors, in particular to a driving device integrated with a speed reducing mechanism.

Background

With the popularization of the current energy saving and emission reduction policies, commercial vehicles and passenger vehicles are greatly developing electric drive technologies, wherein one technical route is a single-motor acceleration and deceleration box.

At present, the radial magnetic field motor is generally matched with the reduction gearbox in the market, and the radial magnetic field motor and the reduction gearbox share a shell, and a structure for radiating is lacking between the radial magnetic field motor and the reduction gearbox, so that when the radial magnetic field motor operates at a high speed, heat generated by the coil is easily conducted into the reduction gearbox, and further the use efficiency of the reduction gearbox is influenced due to overhigh temperature of the reduction gearbox, and even the reduction gearbox is damaged in severe cases.

Disclosure of Invention

Based on the above, the utility model aims to provide a driving device integrating a speed reducing mechanism, which is used for solving the technical problem that the use efficiency of a speed reducing box is affected due to the fact that heat generated by a coil is easily conducted to the speed reducing box when a motor operates at a high speed in the prior art.

The utility model provides a driving device integrating a speed reducing mechanism, which comprises a shell, wherein the shell comprises a separation shell, one side of the separation shell is provided with the speed reducing mechanism, the other side of the separation shell is provided with the driving mechanism, and a first cooling structure is arranged in the shell wall of the separation shell.

Further, the driving device of the integrated speed reducing mechanism is an axial flux motor, the separation shell forms at least one part of a shell of the axial flux motor, and at least one stator of the axial flux motor is fixed on an end face of the separation shell.

Further, the driving device of the integrated speed reducing mechanism, wherein the first cooling structure comprises a first inlet and a second inlet which are arranged on the outer side wall of the separation shell, and a first cooling flow passage which is arranged in the wall of the separation shell and communicated with the first inlet and the second inlet.

Further, the driving device of the integrated speed reducing mechanism, wherein the first cooling runner comprises a first flow guiding runner communicated with the first inlet and outlet, and a first runner body communicated with the first flow guiding runner, one end of the first runner body far away from the first flow guiding runner is communicated with the second inlet and outlet, and the first runner body is blocked by a flow blocking table and is relatively annular.

Further, the driving device of the integrated speed reducing mechanism is characterized in that a plurality of first bending flow channels are annularly arranged on the first flow channel body, and the first bending flow channels are connected with the first flow channel body in series or in parallel; the first curved runner is provided with an outer edge and an inner edge which are oppositely arranged, the outer edge and the outer side of the first guide runner are aligned to the same arc line, and a first fixing hole is formed in one side, away from the outer edge, of the inner edge.

Further, the driving device of the integrated speed reducing mechanism further comprises a first shell and a second shell, wherein the first shell is arranged on one side of the separation shell, the second shell is arranged on the other side of the separation shell, the speed reducing mechanism is arranged between the first shell and the separation shell, and the driving mechanism is arranged between the separation shell and the second shell.

Further, the driving device of the integrated speed reducing mechanism is characterized in that a second cooling structure is arranged in a shell wall of the second shell, and the second cooling structure comprises a third inlet and a fourth inlet which are arranged on the outer side wall of the second shell, and a second cooling flow passage which is arranged in the shell wall of the second shell and is communicated with the third inlet and the fourth outlet.

Further, the driving device of the integrated speed reducing mechanism, wherein the second cooling flow channel comprises a second flow guiding channel communicated with the third inlet and outlet, and a second flow channel body communicated with the second flow guiding channel, one end of the second flow channel body, far away from the second flow guiding channel, is communicated with the fourth inlet and outlet, and a turbulence table is arranged in the second flow channel body.

Further, the driving device of the integrated speed reducing mechanism is characterized in that any inlet and outlet of the second cooling structure is communicated with any inlet and outlet of the first cooling structure through a U-shaped pipe.

Further, the driving device of the integrated speed reducing mechanism is a planetary speed reducing mechanism, and the planetary speed reducing mechanism comprises a sun gear, a planet gear, an inner gear ring, a planet carrier and a power output shaft.

Compared with the prior art, the technical scheme has the following advantages:

1. through set up first cooling structure in separating the shell to when realizing separating shell one side actuating mechanism cooling, can also separate the reduction gears cooling of shell opposite side, effectively prevent the heat conduction that actuating mechanism produced for reduction gears.

2. The speed reducing mechanism and the driving mechanism share one separating shell, so that the axial size of the whole driving device is further reduced, the weight is reduced, the size is reduced, and the integration of the driving device is improved.

3. The axial flux motor is adopted as a driving mechanism, and compared with the traditional radial magnetic field motor, the axial flux motor has the advantages of shorter axial dimension, smaller volume and lighter weight, and further shortens the overall axial dimension of the driving device.

Drawings

FIG. 1 is a block diagram of a driving apparatus incorporating a reduction mechanism according to the present utility model;

FIG. 2 is a schematic diagram of a driving device with an integrated speed reducing mechanism according to the present utility model;

FIG. 3 is a cross-sectional view of a drive device incorporating a reduction mechanism in accordance with the present utility model;

FIG. 4 is a block diagram of a reduction mechanism according to the present utility model;

FIG. 5 is a cross-sectional view taken at position A-A of FIG. 4;

FIG. 6 is a cross-sectional view of the B-B position of FIG. 4;

description of main reference numerals:

10. a housing; 11. a separation shell; 12. a first housing; 13. a second housing; 20. a first cooling structure; 21. a first access port; 22. a second inlet and outlet; 231. a first flow guide channel; 232. a first flow channel body; 233. a flow blocking table; 234. a first curved flow path; 235. an outer edge; 236. an inner edge; 237. a first fixing hole; 30. a speed reducing mechanism; 31. a sun gear; 32. a planet wheel; 33. an inner gear ring; 34. a planet carrier; 35. a power output shaft; 36. a third bearing; 37. a fourth bearing; 40. a driving mechanism; 41. a rotor shaft; 42. a rotor disc; 43. a first stator; 431. a stator core; 432. a coil; 44. a second stator; 45. a first bearing; 46. a second bearing; 50. a second cooling structure; 51. a third inlet and outlet; 52. a fourth inlet and outlet; 531. a second flow guide channel; 532. a second flow channel body; 533. a second curved flow path; 534. a turbulent flow table; 535. a second fixing hole; 60. u-shaped tube.

The utility model will be further described in the following detailed description in conjunction with the above-described figures.

Detailed Description

In order that the utility model may be readily understood, a more complete description of the utility model will be rendered by reference to the appended drawings. Several embodiments of the utility model are presented in the figures. This utility model may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "mounted" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like are used herein for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs. The terminology used herein in the description of the utility model is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1, the driving device of the integrated speed reducing mechanism in the present utility model includes a housing 10, the housing 10 includes a separation housing 11, one side of the separation housing 11 is provided with a speed reducing mechanism 30, the other side is provided with a driving mechanism 40, and a first cooling structure 20 is disposed in a wall of the separation housing 11.

It can be appreciated that the first cooling structure 20 is arranged in the separation shell 11, so that the driving mechanism 40 at one side of the separation shell 11 can be cooled, the speed reducing mechanism 30 at the other side of the separation shell 11 can be cooled, heat generated by the driving mechanism 40 is effectively prevented from being transmitted to the speed reducing mechanism 30, the use efficiency of the speed reducing mechanism 30 is effectively prevented from being influenced due to overhigh temperature of the speed reducing mechanism 30, and the service life of the speed reducing mechanism 30 is prolonged. Secondly, the reduction mechanism 30 and the driving mechanism 40 share one separating shell 11, so that the axial size of the whole driving device is further reduced, the weight is reduced, the size is reduced, the integration of the driving device is improved, the number of parts is reduced, and the assembly is convenient.

Referring specifically to fig. 2 to 3, the housing 10 further includes a first housing 12 and a second housing 13, the first housing 12 is disposed on one side of the separation housing 11, the second housing 13 is disposed on the other side of the separation housing 11, the speed reducing mechanism 30 is disposed between the first housing 12 and the separation housing 11, and the driving mechanism 40 is disposed between the separation housing 11 and the second housing 13. In the present embodiment, the driving mechanism 40 is preferably an axial flux motor, the partition 11 and the second housing 13 constitute a casing of the axial flux motor, the reduction mechanism 30 is preferably a planetary reduction mechanism, and the partition 11 and the first housing 12 constitute a casing of the planetary reduction mechanism, wherein the reduction mechanism 30 is not limited to a planetary reduction mechanism, but may be a gear set reduction mechanism 30 or the like.

In this embodiment, since the axial flux motor is an axial magnetic field, the direction of increasing power is developed radially, so that the motor with very high power can be very flat, and the motor is very suitable for occasions with small installation position dimensions. Compared with the traditional radial magnetic field motor, the axial magnetic flux motor has the advantages of short axial dimension, smaller volume, lighter weight, short overall axial dimension, improved integration of the driving device, and about 30% lighter weight than the common radial permanent magnet motor under the same output power.

In addition, the combination mode of the axial flux motor plus-planetary speed reducing mechanism is adopted, so that the weight and the axial size of the whole driving device are greatly reduced, and the compactness of the structure is improved.

Referring specifically to fig. 3, for ease of understanding, the cavity formed between the first housing 12 and the partition 11 is referred to as a first cavity, and the cavity formed between the partition 11 and the second housing 13 is referred to as a second cavity.

The driving mechanism 40 in this embodiment includes a rotor shaft 41, a rotor disc 42 and a stator, wherein one end of the rotor shaft 41 extends into the first cavity, the other end is rotatably disposed in a bearing chamber of the second housing 13 through a first bearing 45, a second bearing 46 is disposed at a shaft hole position of the spacer 11, and the second bearing 46 is sleeved on the rotor shaft 41 for auxiliary transmission;

the stator may include a first stator 43 and a second stator 44, where the first stator 43 is fixedly disposed on an end surface of the middle housing 11 in the second cavity, the second stator 44 is fixedly disposed on an end surface of the second housing 13 in the second cavity, and the rotor disc 42 is fixedly disposed on the rotor shaft 41 corresponding to a gap between the first stator 43 and the second stator 44. The stator may also comprise only a first stator 43 fixed on the end face of the partition 11 in the second cavity, thus forming a single stator and single rotor motor structure.

Referring specifically to fig. 5, the first cooling structure 20 includes a first inlet 21 and a second inlet 22 formed on the outer wall of the casing 11, and a first cooling flow passage formed in the casing wall of the casing 11 and communicating the first inlet 21 and the second inlet 22.

In one embodiment, the first inlet and outlet 21 is an inlet, the second inlet and outlet 22 is an outlet, and the cooling medium flows into the first cooling flow passage from the first inlet and outlet 21, flows through the first cooling flow passage clockwise until flowing out from the second inlet and outlet 22, so as to realize heat exchange cooling operation on the speed reducing mechanism 30 and the driving mechanism 40 respectively. The cooling medium comprises a liquid such as water or oil. In another embodiment, the first inlet and outlet 21 may be an outlet, and the second inlet and outlet 22 may be an inlet, and the cooling medium may be injected into the partition 11 in various flow patterns.

Specifically, the first cooling flow channel includes a first flow guiding channel 231 that communicates with the first inlet and outlet 21, and a first flow channel body 232 that communicates with the first flow guiding channel 231, where an end of the first flow channel body 232 that is far away from the first flow guiding channel 231 communicates with the second inlet and outlet 22. In this embodiment, the first inlet and outlet 21 is an inlet, the second inlet and outlet 22 is an outlet, firstly, the cooling medium flows into the first flow guiding channel 231 from the first inlet and outlet 21, then flows into the first flow channel body 232 in a reverse folding manner, and finally is discharged from the second inlet and outlet 22, wherein the first flow guiding channel 231 mainly plays a role of guiding to ensure that the cooling medium flows clockwise along the track of the first flow channel body 232, so as to avoid that the cooling medium enters the first flow channel body 232 in a diffusion manner to reduce the heat exchange effect.

Specifically, the first flow channel body 232 is blocked by a blocking table 233 and has a ring shape. So that the cooling medium irreversibly flows through the first flow path body 232 while increasing the area of the first flow path body 232 on the separator 11, enhancing the cooling performance. The width of the baffle table 233 is as short as possible, so as to increase the area of the first flow channel body 232, and improve the heat exchange effect of the first flow channel body 232 on the stator and the speed reducing mechanism 30.

With continued reference to fig. 5, the first flow channel body 232 has a plurality of first curved flow channels 234 in an annular array, and in this embodiment, the first curved flow channels 234 are connected in series with the first flow channel body 232 to form a continuously bent serpentine channel, so as to increase the flow path of the cooling medium, so that the cooling medium can stay in the wall of the separation shell 11 for a longer time, and ensure that the cooling medium has sufficient time to exchange heat with the speed reducing mechanism 30 and the driving mechanism 40.

The first curved flow channel 234 and the first flow channel body 232 may also be connected in parallel, but are not limited to being connected in series.

Referring to fig. 3 and 5, the first curved flow channels 234 have an outer edge 235 and an inner edge 236 that are opposite to each other, the outer edge 235 is aligned with the outer side of the first flow guide channel 231 in the same arc, and a side of the inner edge 236 facing away from the outer edge 235 is provided with a first fixing hole 237, where the first fixing hole 237 is used to fix the first stator 43 on the end surface of the partition shell 11 by using a fastener, and it should be noted that, in this embodiment, instead of the inner edge 236 of each first curved flow channel 234, a first fixing hole 237 is formed at each first curved flow channel 234, but in practical application, the number of the first fixing holes 237 may be determined according to the number of stator cores 431, and is not limited to the solution shown in this embodiment.

Specifically, the first stator 43 in this embodiment is formed by a plurality of stator cores 431 in annular arrays, each stator core 431 is sleeved with a corresponding coil 432, each stator core 431 corresponds to one first fixing hole 237 and is fixed by a bolt, so that the stator core 431 is tightly attached to the end face of the separation shell 11, wherein the first curved flow channel 234 is arranged around the outline of the stator core 431, and can effectively absorb heat generated by the coil 432 and the stator core 431 and effectively improve the cooling effect on the first stator 43.

Further, referring to fig. 6 specifically, a second cooling structure 50 may be further provided in a wall of the second housing 13 for cooling the second stator 44, where the second cooling structure 50 includes a third inlet and outlet 51 and a fourth inlet and outlet 52 provided on an outer side wall of the second housing 13, and a second cooling flow passage provided in the wall of the second housing 13 and communicating the third inlet and outlet 51 and the fourth inlet and outlet 52.

In one embodiment, the third inlet and outlet 51 is an inlet, the fourth inlet and outlet 52 is an outlet, and the cooling medium enters from the third inlet and outlet 51 into the second cooling flow passage, flows through the second cooling flow passage counterclockwise until flowing out from the fourth inlet and outlet 52, so as to realize heat exchange cooling operation on the second stator 44. In another embodiment, the third inlet and outlet 51 may be an outlet, and the fourth inlet and outlet 52 may be an inlet, and the cooling medium may be injected into the second housing 13 in various flow patterns.

In this embodiment, the second cooling flow channel includes a second flow guiding channel 531 connected to the third inlet and outlet 51, and a second flow channel body 532 connected to the second flow guiding channel 531, and one end of the second flow channel body 532 away from the second flow guiding channel 531 is connected to the fourth inlet and outlet 52, where a plurality of second curved flow channels 533 are annularly arranged on the second flow channel body 532, and in this embodiment, the second curved flow channels 533 and the second flow channel body 532 are connected in series and form a continuously-bent serpentine water channel, so as to increase the flow path of the cooling medium, so that the cooling medium can stay on the wall of the second housing 13 for a longer time, and ensure that the cooling medium has sufficient time to exchange heat with the second stator 44.

In addition, a second fixing hole 535 is provided at the inner edge 236 of the second curved flow channel 533, which functions as the first fixing hole 237, and thus reference is made to the above description of the first fixing hole 237 for the function of the second fixing hole 535.

In this embodiment, the second cooling flow channel is different from the first cooling flow channel in that a spoiler 534 is further disposed in the second flow channel body 532, and specifically disposed in the second curved flow channels 533, two spoiler 534 are disposed in each second curved flow channel 533, and the two spoiler 534 are respectively located at corner positions of the second curved flow channel 533. The number of the turbulence tables 534 is not limited, and may be specifically adjusted according to the shape of the second cooling flow channel. It will be appreciated that the turbulator 534 serves to achieve turbulence to increase the flow rate of the cooling medium, increase the contact area of the cooling medium with the second stator 44, and enhance cooling performance.

Referring specifically to fig. 2, in one embodiment, the fourth port 52 is in communication with the second port 22 via a U-tube 60. In order to realize the series connection of the first cooling flow passage and the second cooling flow passage, the cooling medium can flow in and flow through the first cooling flow passage, the U-shaped pipe 60 and the second cooling flow passage from the first inlet and outlet 21, and finally be discharged from the third inlet and outlet 51, and the cooling of the speed reducing mechanism 30, the first stator 43 and the second stator 44 can be realized by one cycle, and of course, the third inlet and outlet can also be used as an inlet, and the position of the cooling medium inlet is not limited.

In another embodiment, the first cooling flow channel and the second cooling flow channel can be independent, that is, the first cooling flow channel is only used for cooling the speed reducing mechanism 30 and the first stator 43, and the second cooling flow is only used for cooling the second stator 44, so that the cooling effect is better.

Referring specifically to fig. 4, as well, for ease of understanding, the cavity formed between the first housing 12 and the partition 11 is referred to as a first cavity, and the cavity formed between the partition 11 and the second housing 13 is referred to as a second cavity.

The speed reduction mechanism 30 in this embodiment is a planetary speed reduction mechanism, the planetary speed reduction mechanism includes a sun gear 31, a planet gear 32, an inner gear ring 33, a planet carrier 34 and a power output shaft 35, the planet carrier 34 is rotatably disposed in the first cavity through a third bearing 36 and a fourth bearing 37, wherein the third bearing 36 is disposed on one side of the first cavity of the casing 11, the fourth bearing 37 is disposed on one side of the first cavity of the casing 12, the sun gear 31 is disposed on the planet carrier 34 and connected with the rotor shaft 41, the planet gear 32 is disposed on the planet carrier 34, the planet gear 32 surrounds the sun gear 31 and is meshed with the sun gear 31, the inner gear ring 33 is disposed on the inner periphery of the first casing 12, the inner teeth of the planet gear ring 33 are meshed with the planet gear ring 32, one end of the power output shaft 35 extends into the first cavity and is connected with the carrier 34, and the other end extends out of the first casing 12 to drive external devices. In practical application, the rotor shaft 41 drives the sun gear 31 to rotate, the sun gear 31 drives the planet gears 32 to rotate, the planet gears 32 drive the planet carrier 34 to rotate, and the planet carrier 34 drives the power output shaft 35 to rotate, so that the equipment is driven. The planetary gears 32 uniformly distributed to share the load, the sun gear 31, the inner gear ring 33 and the planet carrier 34 are on the same central axis, so that the whole structure is compact, and compared with the traditional speed reducing mechanism, the speed reducing mechanism has smaller volume and lighter weight.

In addition, the structure has fewer parts, the power output shaft 35 and the rotor shaft 41 are coaxial, the structure is simple, the installation is convenient, and the planetary reduction mechanism simultaneously has a plurality of tooth surfaces to uniformly bear impact load, and the impact resistance of the planetary reduction mechanism is improved.

In summary, in the driving device integrated with the speed reducing mechanism according to the above embodiment of the present utility model, the first cooling structure 20 is disposed in the casing 11, so as to cool the driving mechanism 40 on one side of the casing 11, and cool the speed reducing mechanism 30 on the other side of the casing 11, thereby effectively preventing heat generated by the driving mechanism 40 from being transmitted to the speed reducing mechanism 30. The reduction mechanism 30 and the driving mechanism 40 share one separating shell 11, so that the axial size of the whole driving device is further reduced, the weight is reduced, the size is reduced, and the integration of the driving device is improved. And the axial flux motor is adopted as a driving mechanism, so that the axial size of the axial flux motor is shorter, the volume is smaller, the weight is lighter, and the overall axial size of the driving device is further shortened compared with the traditional radial magnetic field motor.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing examples illustrate only a few embodiments of the utility model and are described in detail herein without thereby limiting the scope of the utility model. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model. Accordingly, the scope of protection of the present utility model is to be determined by the appended claims.

Claims (10)

1. The driving device integrated with the speed reducing mechanism is characterized by comprising a shell, wherein the shell comprises a separation shell, one side of the separation shell is provided with the speed reducing mechanism, the other side of the separation shell is provided with the driving mechanism, and a first cooling structure is arranged in the shell wall of the separation shell.

2. A driving device integrated with a reduction mechanism according to claim 1, characterized in that the driving mechanism is an axial flux motor, the separator forms at least a part of a housing of the axial flux motor, and at least one stator of the axial flux motor is fixed on an end face of the separator.

3. The driving device for an integrated reduction mechanism according to claim 1 or 2, wherein the first cooling structure includes a first inlet and a second outlet provided on an outer side wall of the partition case, and a first cooling flow passage provided in a wall of the partition case communicating the first inlet and the second outlet.

4. A driving device for an integrated speed reducing mechanism according to claim 3, wherein said first cooling flow path comprises a first flow guide path communicating with said first inlet and outlet, and a first flow path body communicating with said first flow guide path, wherein an end of said first flow path body remote from said first flow guide path communicates with said second inlet and outlet, and said first flow path body is blocked by a flow blocking table and relatively takes a ring shape.

5. The driving device of claim 4, wherein the first flow channel body is provided with a plurality of first curved flow channels in an annular array, and the first curved flow channels are connected in series or in parallel with the first flow channel body; the first curved runner is provided with an outer edge and an inner edge which are oppositely arranged, the outer edge and the outer side of the first guide runner are aligned to the same arc line, and a first fixing hole is formed in one side, away from the outer edge, of the inner edge.

6. The drive device of claim 1 or 2, wherein the housing further comprises a first housing and a second housing, the first housing is disposed on one side of the separator, the second housing is disposed on the other side of the separator, the speed reducing mechanism is disposed between the first housing and the separator, and the drive mechanism is disposed between the separator and the second housing.

7. The driving device of claim 6, wherein a second cooling structure is provided in a wall of the second housing, the second cooling structure includes a third inlet and a fourth inlet provided on an outer sidewall of the second housing, and a second cooling flow passage provided in the wall of the second housing and communicating the third inlet and the fourth outlet.

8. The integrated reduction gear transmission driving device according to claim 7, wherein the second cooling flow path includes a second flow guide path communicating with the third inlet and outlet, and a second flow path body communicating with the second flow guide path, an end of the second flow path body remote from the second flow guide path communicating with the fourth inlet and outlet, and a spoiler is provided in the second flow path body.

9. The driving device of claim 7, wherein any one of the inlet and outlet of the second cooling structure is communicated with any one of the inlet and outlet of the first cooling structure through a U-shaped pipe.

10. The drive device of claim 1 or 2, wherein the speed reduction mechanism is a planetary speed reduction mechanism comprising a sun gear, a planet gear, an inner gear ring, a planet carrier and a power output shaft.