Cooling structure for integrated electric drive system and integrated electric drive system

Abstract

A cooling structure for an integrated electric drive system and an integrated electric drive system, the cooling structure including a motor assembly (1), the motor assembly (1) including a rotating shaft (15) and a cooling pipe (16) having an inner hole (161), the rotating shaft (15) having a mounting hole (151) for inserting the cooling pipe, an annular water passage (17) formed between the outer wall of the cooling pipe (16) and the inner wall of the mounting hole (151), the inner hole (161) and the annular water passage (17) constituting a rotor cooling water passage (12).

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application is based on and claims priority to a Chinese patent application having application number 202011195481.8, filed on October 30, 2020, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the technical field of cooling an electric drive system of an automobile, and in particular to a cooling structure for an integrated electric drive system and an integrated electric drive system. [Background technology]

[0003] The electric drive system is a core component of an electric vehicle, and with the development of new energy vehicles, the layout requirements for the drive system of the vehicle are becoming higher and higher. The electric drive system is composed of components such as a drive motor, a controller, and a transmission, and the heat-generating elements in the controller release a large amount of heat during operation, and the stator and rotor of the motor also release a large amount of heat during rotation. In the prior art, the electric drive system is provided with multiple cooling water channels for heat dissipation, but the heat dissipation effect of the cooling water channels in the prior art is always low, so the heat dissipation speed of the controller and the motor in the electric drive system is low, and the cooling effect is low. Summary of the Invention

[0004] The present application provides a cooling structure for an integrated electric drive system and an integrated electric drive system, which solves the technical problems, such as low heat dissipation rate and low cooling effect, that exist in the cooling water channels of electric drive systems in the prior art.

[0005] In view of the above problems, a cooling structure for an integrated electric drive system according to an embodiment of the present application includes a motor assembly, the motor assembly including a rotating shaft and a cooling pipe having an inner hole, the rotating shaft having a mounting hole for inserting the cooling pipe, an annular water passage formed between an outer wall of the cooling pipe and an inner wall of the mounting hole, and the inner hole and the annular water passage constituting a rotor cooling water passage.

[0006] In one embodiment of the present application, the rotating shaft includes an intermediate rotor, and a first rotor and a second rotor connected to opposite ends of the intermediate rotor, and the mounting holes include a first through hole provided in the first rotor and a second through hole provided in the intermediate rotor, and the first through hole communicates with the second through hole.

[0007] In one embodiment of the present application, the intermediate rotor further includes a plurality of branch grooves spaced apart in a circumferential direction centered on the second through hole, and all of the branch grooves communicate with the second through hole.

[0008] In one embodiment of the present application, a diameter of the bore gradually decreases along a first direction, the first direction being a direction from an end of the bore where the cooling liquid enters to an end of the bore where the cooling liquid exits; A cross-sectional area of ​​the annular water channel perpendicular to the axis of the rotation shaft gradually decreases along a second direction, the second direction being a direction from the end of the annular water channel where the cooling liquid flows in to the end where the cooling liquid flows out, and the first direction being opposite to the second direction.

[0009] In one embodiment of the present application, the cooling structure of the integrated electric drive system further includes a controller case attached to the motor assembly, an electrically controlled cooling water passage is provided in the controller case, a stator cooling water passage is provided in the motor assembly, the inner hole is connected to the electrically controlled cooling water passage, and the annular water passage is connected to the stator cooling water passage.

[0010] In one embodiment of the present application, the motor assembly includes a motor case, the rotating shaft is mounted within the motor case, the controller case is mounted to the motor case, and the stator cooling water passage is provided in the motor case.

[0011] In one embodiment of the present application, the electrically controlled cooling water channel is provided at opposite ends with a water channel inlet and an electrically controlled water channel outlet, The motor assembly further includes a cover plate and an end cover for attaching the rotating shaft to the motor case, the end cover being attached to the motor case, and the cover plate being attached to an end surface of the end cover that faces away from the motor case, A connecting water passage is provided in the cover plate, and a first communicating passage, a second communicating passage, and a third through hole communicating with the mounting hole are provided in the end cover, one end of the cooling pipe is attached to the cover plate and the other end passes through the third through hole and is inserted into the mounting hole, the annular water passage is connected to the stator cooling water passage by the first communicating passage, and the electrically controlled cooling water passage is connected to the inner hole by the second communicating passage and the connecting water passage, in turn.

[0012] In one embodiment of the present application, the motor assembly further includes a mechanical seal including a rotating ring and a fixed ring fixed to an inner wall of the third through hole, the rotating ring being fitted onto the rotating shaft and rotating together with the rotating shaft, and the fixed ring being fitted into the rotating ring and rotatably connected to the rotating ring.

[0013] In one embodiment of the present application, the stator cooling water passage includes a plurality of straight water passages provided at intervals in the motor case, and a plurality of transition water passages connecting two adjacent straight water passages.

[0014] In the present application, a cooling pipe having an inner hole is inserted into a mounting hole of a rotating shaft, and an annular water passage is formed between an outer wall of the cooling pipe and an inner wall of the mounting hole, the inner hole and the annular water passage constitute a rotor cooling water passage of a motor assembly, and the inner hole is connected to the annular water passage, and the cooling liquid flows in from the inner hole of the cooling pipe, flows through the entire inner hole and the annular water passage in order, and then flows out from the annular water passage. During the flow process of the cooling liquid, the direction of the cooling liquid flowing through the inner hole is opposite to the direction of the cooling liquid flowing through the annular water passage.

[0015] Due to the design in which the mounting hole of the rotating shaft and the inner hole of the cooling pipe are fitted together, the coolant flows into the inner hole at a small flow rate, but after flowing into the annular water channel, the small flow rate contacts the inner wall of the mounting hole of the rotating shaft with a maximum contact area, thereby maximally cooling the rotating shaft and rotor. This enhances the effect of the coolant cooling the rotating shaft and stator in the rotor cooling water channel, and ensures that the coolant can fully absorb the heat released from the rotating shaft and rotor of the motor assembly with a small flow rate into the inner hole and the annular water channel, thereby improving the heat dissipation efficiency of the cooling structure of the integrated electric drive system and extending the service life of the motor assembly.

[0016] An integrated drive system according to an embodiment of the present application includes a cooling structure for the integrated electric drive system.

[0017] In order to describe the technical solutions of the present application more clearly, the drawings which need to be used in the embodiments are briefly described below. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram of a cooling structure for an integrated electric drive system according to an embodiment of the present application. [Diagram 2] FIG. 2 is a cross-sectional view of a cooling structure of an integrated electric drive system according to an embodiment of the present application. [Diagram 3] FIG. 2 is an exploded schematic diagram of a cooling structure of an integrated electric drive system according to an embodiment of the present application. [Figure 4] FIG. 2 is a partial schematic diagram of a cooling structure of an integrated electric drive system according to an embodiment of the present application. [Diagram 5] FIG. 2 is a schematic configuration diagram of an end cover of a cooling structure for an integrated electric drive system according to an embodiment of the present application. [Figure 6] FIG. 13 is a schematic configuration diagram of an end cover of a cooling structure for an integrated electric drive system according to another embodiment of the present application. [Figure 7] FIG. 13 is a schematic diagram of an end cover of a cooling structure for an integrated electric drive system according to yet another embodiment of the present application. [Figure 8] FIG. 2 is a schematic configuration diagram of a rotating shaft of a cooling structure of an integrated electric drive system according to an embodiment of the present application. [Figure 9] 1 is a cross-sectional view of a rotating shaft of a cooling structure of an integrated electric drive system according to an embodiment of the present application. [Figure 10] FIG. 2 is a cross-sectional view of an intermediate rotor of a cooling structure of an integrated electric drive system according to an embodiment of the present application. [Figure 11] FIG. 2 is a plan view of an intermediate rotor of a cooling structure of an integrated electric drive system according to an embodiment of the present application. [Figure 12] FIG. 2 is a schematic configuration diagram of a motor case of a cooling structure of an integrated electric drive system according to an embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] In order to clarify the technical problems, technical means and advantageous effects that the present application aims to solve, the present application will be described in more detail below with reference to the drawings and examples. It should be understood that the specific examples described in this specification are merely for the purpose of interpreting the present application, and do not limit the present application.

[0020] Any orientations or positions indicated using the terms "upper," "lower," "left," "right," "front," "rear," "middle," etc. are based on the orientations or positions shown in the drawings and are intended merely to facilitate and simplify the description of the present application, and are not to be construed as limiting the present application, as they do not indicate or suggest that the devices or parts shown have a particular orientation or must be configured and operated in a particular orientation.

[0021] In this application, in order to better show the structure and connection relationship of the cooling structure of the integrated electric drive system, the "front end" referred to in this application actually faces the front end of the motor assembly (i.e., the right side in FIG. 2), and the end described in this application actually faces the end of the motor assembly (i.e., the left side in FIG. 2).

[0022] As shown in Figures 1, 2 and 9, a cooling structure for an integrated electric drive system according to one embodiment of the present application includes a motor assembly 1, the motor assembly 1 including a rotating shaft 15 and a cooling pipe 16 having an inner hole 161, the rotating shaft 15 being provided with a mounting hole 151 for inserting the cooling pipe, and an annular water passage 17 being formed between the outer wall of the cooling pipe 16 and the inner wall of the mounting hole 151, and the inner hole 161 and the annular water passage 17 constituting a rotor cooling water passage 12.

[0023] In the present application, the cooling pipe 16 having an inner hole 161 is inserted into the mounting hole 151 of the rotating shaft 15, and an annular water passage 17 is formed between the outer wall of the cooling pipe 16 and the inner wall of the mounting hole 151, the inner hole 161 and the annular water passage 17 constitute the rotor cooling water passage 12 of the motor assembly 1, and the inner hole 161 is connected to the annular water passage 17. The cooling liquid flows in from the inner hole 161 of the cooling pipe 16, flows through the entire inner hole 161 and the annular water passage 17 in order, and then flows out from the annular water passage 17. In the flow process of the cooling liquid, the direction of the cooling liquid flowing through the inner hole 161 is opposite to the direction of the cooling liquid flowing through the annular water passage 17.

[0024] Due to the design in which the mounting hole 151 of the rotating shaft 15 and the inner hole 161 of the cooling pipe 16 are fitted together, the coolant flows into the inner hole 161 at a small flow rate, but after flowing into the annular water passage 17, the small flow rate contacts the inner wall of the mounting hole 151 of the rotating shaft 15 with a maximum contact area, so as to maximize the cooling of the rotating shaft 15 and the rotor. This enhances the effect of the coolant cooling the rotating shaft 15 and the stator in the rotor cooling water passage 12, and ensures that the coolant flows into the inner hole 161 and the annular water passage 17 at a small flow rate to fully absorb the heat released from the rotating shaft 15 and the rotor of the motor assembly 1, thereby improving the heat dissipation efficiency of the cooling structure of the integrated electric drive system and prolonging the service life of the motor assembly 1.

[0025] In one embodiment, as shown in Figs. 8 and 9, the rotating shaft 15 includes an intermediate rotor 152, and a first rotor 153 and a second rotor 154 connected to opposite ends of the intermediate rotor 152, and the mounting hole 151 includes a first through hole 1531 provided in the first rotor 153 and a second through hole 1521 provided in the intermediate rotor 152, and the first through hole 1531 communicates with the second through hole 1521. As can be understood, the first rotor 153, the second rotor 154, and the intermediate rotor 152 may be connected by a welding method. In one embodiment of the present application, the first rotor 153, the second rotor 154, and the intermediate rotor 152 are connected by a friction welding method, which does not require a spline between the first rotor 153 and the intermediate rotor 152 and between the second rotor 154 and the intermediate rotor 152. In addition, when using the friction welding method, the hole diameter of the second through hole 1521 can be larger than the hole diameter of the first through hole 1531, thus increasing the contact area between the coolant and the intermediate rotor 152 and improving the cooling efficiency of the rotating shaft 15. In this application, the rotating shaft 15 uses a three-stage mechanism design, and the structure of the rotor of each stage is simple and easy to process, thereby reducing the manufacturing cost of the cooling structure of the integrated electric drive system.

[0026] In addition, the first rotor 153 and the intermediate rotor 152 mainly perform the function of rotational drive, i.e., the first rotor 153 and the intermediate rotor 152 generate a large amount of heat when the motor assembly 1 operates, and the second rotor 154 mainly performs the function of transmitting the rotation of the motor assembly 1 to a transmission mechanism such as a reducer, and generates less heat when the motor assembly 1 operates. Therefore, the first rotor 153 and the intermediate rotor 152 are both provided with the mounting hole 151 through which the coolant flows, thereby achieving the effect of cooling the first rotor 153 and the intermediate rotor 152, and it is not necessary to provide the mounting hole 151 in the second rotor 154.

[0027] 10 and 11, the intermediate rotor 152 further includes a plurality of branch grooves 1522 spaced apart from each other in the circumferential direction around the second through hole 1521, and the plurality of branch grooves 1522 are all connected to the second through hole 1521. As can be understood, the number of the branch grooves 1522 can be set according to actual needs, and the intermediate rotor 152 is provided with 3, 6, 10, etc. of the branch grooves 1522 uniformly arranged in the circumferential direction around the second through hole 1521, and the design of the branch grooves 1522 increases the contact area between the coolant and the intermediate rotor 152, thereby improving the heat dissipation efficiency of the intermediate rotor 152.

[0028] In one embodiment, as shown in Figures 2 and 3, the diameter of the bore 161 (i.e., the inner diameter of the cooling tube 16) is gradually reduced along a first direction, which is a direction from the end of the bore 161 where the coolant enters to the end where the coolant exits. As can be appreciated, the first direction is the direction of the motor assembly 1. Tip From the motor assembly 1 end In the exploded schematic diagram of the cooling structure of the integrated electric drive system shown in FIG. Tip The diameter of the inner hole 161 is larger than that of the motor assembly 1. TipIn the first direction, the diameter of the inner hole 161 is gradually decreased (i.e., the diameter of the end of the inner hole 161 close to the cover plate 18 is large, and the diameter of the end of the inner hole 161 away from the cover plate 18 is gradually decreased). Since the diameter of the inner hole 161 (i.e., the inner diameter of the cooling pipe 16) is gradually decreased along the first direction, the flow velocity of the cooling liquid in the inner hole 161 is gradually increased (i.e., the flow velocity of the cooling liquid in the inner hole 161 is accelerated), further enhancing the cooling efficiency of the rotating shaft 15 by the cooling liquid in the inner hole 161.

[0029] The cross-sectional area of ​​the annular water passage 17 perpendicular to the axis of the rotating shaft 15 (i.e., the outer diameter of the cooling tube 16) gradually decreases along a second direction, the second direction being a direction from an end of the annular water passage 17 where the coolant flows in to an end where the coolant flows out, and the first direction being opposite to the second direction. As can be seen, the second direction is a direction in which the motor assembly 1 end From the motor assembly 1 Tip In the cross-sectional view of the cooling structure of the integrated electric drive system shown in FIG. 2, the cross-sectional area of ​​the annular water passage 17 is small near the tip of the motor assembly 1, and the cross-sectional area of ​​the annular water passage 17 is large near the tip of the motor assembly 1. Tip The cross-sectional area of ​​the annular water passage 17 gradually decreases along the second direction (i.e., the cross-sectional area of ​​the annular water passage 17 is large at the end close to the cover plate 18 and gradually decreases at the end away from the cover plate 18), so that the coolant flowing from the inner hole 161 into the annular water passage 17 gradually increases in flow rate along the annular water passage 17 (i.e., the flow rate of the coolant in the annular water passage 17 is accelerated). The fast-flowing coolant further enhances the cooling efficiency of the rotating shaft 15 and avoids the risk of demagnetization of the permanent magnet steel in the motor assembly 1 due to overheating.

[0030] 1 to 4, the cooling structure of the integrated electric drive system further includes a controller case 2 attached to the motor assembly 1 (attached by a screw connection, welding, or the like), the controller case 2 is provided with an electrically controlled cooling water passage 21, the motor assembly 1 is provided with a stator cooling water passage 11, the inner hole 161 is in communication with the electrically controlled cooling water passage 21, and the annular water passage 17 is in communication with the stator cooling water passage 11. As can be seen, the controller case 2 is further provided with a water passage inlet 22 in communication with the electrically controlled cooling water passage 21, and the motor assembly 1 is provided with a water passage outlet 13 in communication with the stator cooling water passage 11. The controller case 2 is mainly for mounting a motor controller, a vehicle control unit, an on-board charger, a DC converter, etc., and components that are prone to heat generation (e.g., an insulated gate bipolar transistor, etc.) in the controller case 2 are mounted in close contact with the electric control cooling water passage 21, so that the electric control cooling water passage 21 can more easily absorb heat emitted from the components that are prone to heat generation in the controller. In one embodiment of the present application, the stator cooling water passage 11 mainly absorbs heat emitted from the motor case 14 of the motor assembly 1, and the rotor cooling water passage 12 mainly absorbs heat emitted from the rotating shaft 15 of the motor assembly 1.

[0031] The cooling liquid flowing in from the water passage inlet 22 flows in the electrically controlled cooling water passage 21, the rotor cooling water passage 12 and the stator cooling water passage 11 in this order, and then flows out from the water passage outlet 13. In one embodiment of the present application, the cooling liquid sequentially absorbs heat released from the controller in the electrically controlled cooling water passage 21, absorbs heat released from the rotating shaft 15 and rotor of the motor assembly 1 in the rotor cooling water passage 12, and absorbs heat released from the motor case 14 and stator of the motor assembly 1 in the stator cooling water passage 11, and then flows out from the water passage outlet 13.

[0032] In one embodiment of the present application, the cooling liquid flowing in from the water passage inlet 22 flows in the electrically controlled cooling water passage 21, the rotor cooling water passage 12 and the stator cooling water passage 11 in sequence, and then flows out from the water passage outlet 13, thereby sequentially connecting the electrically controlled cooling water passage 21, the rotor cooling water passage 12 and the stator cooling water passage 11. The cooling liquid enters the electrically controlled cooling water passage 21 from the water passage inlet 22, absorbs the heat released from the controller into the electrically controlled cooling water passage 21, then flows into the inner hole 161, and flows from the inner hole 161 into the annular water passage 17. That is, the cooling liquid flows into the rotor cooling water passage 12 to absorb the heat released from the rotating shaft 15 of the motor, then flows into the stator cooling water passage 11 to absorb the heat of the motor case 14, and then flows out from the water passage outlet 13. In the cooling structure of the integrated electric drive system, the electric control cooling water passage 21, the rotor cooling water passage 12 and the stator cooling water passage 11 are connected in series, so that the three cooling water passages (the electric control cooling water passage 21, the rotor cooling water passage 12 and the stator cooling water passage 11) all have the same coolant flow rate, which increases the cooling efficiency of the coolant and improves the cooling effect, i.e., increases the cooling efficiency of the controller, the motor stator and the motor rotor. In addition, since the cooling structure of the integrated electric drive system integrates the motor assembly 1 and the controller case 2, the degree of integration of the cooling structure of the integrated electric drive system is improved, the installation space in the automobile is reduced, and the cooling structure of the integrated electric drive system of the present application is simple in structure and low in manufacturing cost.

[0033] In one embodiment, as shown in Figs. 1 to 3, the motor assembly 1 includes a motor case 14, the rotating shaft 15 is mounted in the motor case 14, the controller case 2 is mounted in the motor case 14 (mounted in a manner such as a screw connection), and the stator cooling water passage 11 is provided in the motor case 14. In one embodiment of the present application, the cooling liquid flowing out of the electric control cooling water passage 21 first enters the rotor cooling water passage 12 to absorb heat released from the rotating shaft 15 and the rotor, then flows into the stator cooling water passage 11 to absorb heat released from the motor case 14 and the stator, and then flows out from the water passage outlet 13. As a result, the cooling liquid in the rotor cooling water passage 12 and the stator cooling water passage 11 can completely absorb the heat released from the motor assembly 1, further ensuring the normal operation of the motor assembly 1 and extending the service life of the motor assembly 1.

[0034] 2 and 3, the motor assembly 1 further includes a cooling pipe 16 having an inner hole 161, the rotating shaft 15 is provided with a mounting hole 151 for inserting the cooling pipe 16, an annular water passage 17 is formed between an outer wall of the cooling pipe 16 and an inner wall of the mounting hole 151, one end of the inner hole 161 is connected to the electrically controlled cooling water passage 21 and the other end is connected to the annular water passage 17, and the inner hole 161 and the annular water passage 17 constitute the rotor cooling water passage 12. As can be understood, the cooling pipe 16 is clearance-fitted with the mounting hole 151 and does not move during rotation of the rotating shaft 15.

[0035] The cooling liquid flowing in from the electrically controlled cooling water passage 21 flows in sequence through the inner hole 161 and the annular water passage 17, and then flows into the stator cooling water passage 11. In one embodiment of the present application, the cooling liquid flows through the inner hole 161, exits from the end of the cooling pipe 16, flows into the annular water passage 17 along the axis of the rotating shaft 15, and then enters the stator cooling water passage 11. In the present application, the rotor cooling water passage 12 includes the inner hole 161 and the annular water passage 17, and the direction in which the cooling liquid flows through the inner hole 161 is opposite to the direction in which the cooling liquid flows through the annular water passage 17, thereby further enhancing the cooling effect of the rotating shaft 15 by the cooling liquid in the rotor cooling water passage 12, and further extending the service life of the motor assembly 1.

[0036] In one embodiment, as shown in Figures 2 and 3, a water channel inlet 22 and an electrically controlled water channel outlet 23 are provided at opposite ends of the electrically controlled cooling water channel 21, and in one embodiment of the present application, the water channel outlet 13 of the electrically controlled water channel outlet 23 is provided toward the motor assembly 1.

[0037] The motor assembly 1 includes a cover plate 18 and an end cover 19 for mounting the rotating shaft 15 to the motor case 14, the end cover 19 being attached to the motor case 14 (by a method such as a screw connection or welding), and the cover plate 18 being attached to an end face of the end cover 19 away from the motor case 14 (by a method such as a screw connection or welding). As can be understood, the end cover 19 is attached to the rear end of the motor case 14 along the axial direction of the rotating shaft 15.

[0038] A connecting water passage 181 is provided in the cover plate 18, a first communication passage 191, a second communication passage 192, and a third through hole 193 communicating with the mounting hole 151 are provided in the end cover 19, and one end of the cooling pipe 16 is attached to the cover plate 18 and the other end passes through the third through hole 193 and is inserted into the mounting hole 151. The annular water passage 17 communicates with the stator cooling water passage 11 by the first communication passage 191, and the electrically controlled cooling water passage 21 communicates with the inner hole 161 by the second communication passage 192 and the connecting water passage 181 in turn. As can be understood, when the motor case 14 is mounted on the motor assembly 1, the electrical control water passage outlet 23 is sealedly connected to the second communication passage 192, so that the cooling liquid flowing out of the electrical control water passage outlet 23 flows through the second communication passage 192 and into the inner hole 161, the cooling liquid in the inner hole 161 flows through the annular water passage 17 and into the first communication passage 191, and the cooling liquid in the first communication passage 191 further flows into the stator cooling water passage 11, and after absorbing the heat released from the motor case 14 in the stator cooling water passage 11, it flows out from the water passage outlet 13. In this application, the cooling structure of the integrated electric drive system has a simple processing process and a low manufacturing cost.

[0039] In one embodiment, as shown in FIG. 2, the motor assembly 1 further includes a mechanical seal 100 including a rotating ring and a fixed ring fixed to the inner wall of the third through hole 193, the rotating ring being fitted onto the rotating shaft 15 and rotating together with the rotating shaft 15, and the fixed ring being fitted into the rotating ring and rotatably connected to the rotating ring. In one embodiment of the present application, both opposing ends of the rotating shaft 15 are mounted in the motor case 14 by first and second bearings, respectively. When the rotating shaft 15 is in a state of high-speed rotation and it is necessary to ensure that the coolant in the annular water passage 17 does not leak, the mechanical seal 100 is mounted on the end of the rotating shaft 15 close to the end cover 19. The mechanical seal 100 has a rotating ring that can rotate together with the rotating shaft 15 and a fixed ring that is fixed to the inner wall of the third through hole 193, and ensures sealing when the rotating ring and the fixed ring rotate relative to each other, thereby ensuring that the coolant in the annular water passage 17 does not leak, avoiding short-circuit accidents of the motor assembly 1, and extending the service life of the cooling structure of the integrated electric drive system.

[0040] 12, the stator cooling water passage 11 includes a plurality of straight water passages (not shown) spaced apart from each other in the motor case 14, and a plurality of transition water passages (not shown) connecting two adjacent straight water passages. As can be understood, the number of the straight water passages can be designed according to actual needs, and the stator cooling water passage 11 is arranged in an "S" shape in the motor case 14, and the flow directions of the coolant in the two adjacent straight water passages are opposite to each other, thereby improving the heat absorption efficiency of the coolant in the straight water passages.

[0041] 1 and 8, in one embodiment, the cooling structure for the integrated electric drive system further includes a reducer case attached to the motor case 14. An output gear 155 is provided on an outer wall of the rotating shaft 15, and a reducer body is attached in the motor case 14, and the reducer body includes a reduction gear that meshes with the output gear 155. In the present application, the reducer is further integrated in the cooling structure for the integrated electric drive system, thereby further improving the integration degree and reducing the installation space of the cooling structure for the integrated electric drive system in the automobile.

[0042] An integrated electric drive system according to another embodiment of the present application includes a cooling structure for the integrated electric drive system.

[0043] The above describes the examples of the present application in detail, and the principles and embodiments of the present application are explained using specific examples in this specification. However, the above description of the examples is merely intended to aid in understanding the method and gist of the present application. [Explanation of symbols]

[0044] 1 Motor Assembly 11 Stator cooling water passage 12 Rotor cooling water channel 13 Waterway outlet 14 Motor case 15 Rotational Axis 151 Mounting hole 152 Intermediate rotor 1521 Second Through Hole 1522 Branch ditch 153 First Rotor 1531 First Through Hole 154 Second Rotor 155 Output gear 16 Cooling pipe 161 Inner Hole 17 Circular Waterway 18 Cover plate 181 Connecting Waterway 19 End cover 191 1st communication passage 192 2nd communication passage 193 3rd Through Hole 100 Mechanical Seal 2 Controller Case 21 Electrically controlled cooling water channel 22 Waterway entrance 23 Electrically controlled waterway outlet 3 Reducer

Claims

1. a motor assembly including a rotating shaft and a cooling pipe having an inner hole, the rotating shaft being provided with a mounting hole for inserting the cooling pipe, an annular water passage being formed between an outer wall of the cooling pipe and an inner wall of the mounting hole, the inner hole and the annular water passage constituting a rotor cooling water passage; The annular water passage communicates with a stator cooling water passage provided in the motor assembly, The stator cooling water passage is provided in an "S" shape in the motor case, and includes a plurality of straight water passages provided at intervals in the motor case, and a plurality of transition water passages connecting two adjacent straight water passages, and the flow directions of the cooling liquid in the two adjacent straight water passages are opposite to each other; a controller case attached to the motor assembly, the controller case being provided with an electric control cooling water passage, the inner hole being in communication with the electric control cooling water passage; the electrically controlled cooling water passage, the rotor cooling water passage, and the stator cooling water passage are connected in series in this order. A cooling structure for an integrated electric drive system.

2. 2. The cooling structure for an integrated electric drive system according to claim 1, wherein the rotating shaft includes an intermediate rotor, and a first rotor and a second rotor connected to opposite ends of the intermediate rotor, the mounting holes include a first through hole provided in the first rotor and a second through hole provided in the intermediate rotor, and the first through hole communicates with the second through hole.

3. 3. The cooling structure for an integrated electric drive system according to claim 2, wherein the intermediate rotor further includes a plurality of branch grooves spaced apart from one another in a circumferential direction about the second through hole, and each of the plurality of branch grooves communicates with the second through hole.

4. a diameter of the bore gradually decreases along a first direction, the first direction being a direction from an end of the bore where a cooling fluid enters to an end of the bore where a cooling fluid exits; 4. The cooling structure of an integrated electric drive system according to claim 1, wherein a cross-sectional area of ​​the annular water channel perpendicular to an axis of the rotation shaft gradually decreases along a second direction, the second direction being a direction from an end of the annular water channel where the cooling liquid flows in to an end of the annular water channel where the cooling liquid flows out, and the first direction being opposite to the second direction.

5. 2. The cooling structure of the integrated electric drive system according to claim 1, wherein the motor assembly includes a motor case, the rotating shaft is mounted within the motor case, and the controller case is mounted to the motor case.

6. A water channel inlet and an electrically controlled water channel outlet are provided at opposite ends of the electrically controlled cooling water channel, The motor assembly further includes a cover plate and an end cover for attaching the rotating shaft to the motor case, the end cover being attached to the motor case, and the cover plate being attached to an end surface of the end cover that faces away from the motor case, 6. The cooling structure of an integrated electric drive system according to claim 1, wherein the cover plate is provided with a connecting water passage, the end cover is provided with a first communicating passage, a second communicating passage, and a third through hole communicating with the mounting hole, one end of the cooling pipe is attached to the cover plate and the other end passes through the third through hole and is inserted into the mounting hole, the annular water passage is connected to the stator cooling water passage by the first communicating passage, and the electrically controlled cooling water passage is connected to the inner hole by the second communicating passage and the connecting water passage, in order.

7. 7. The cooling structure of the integrated electric drive system according to claim 6, wherein the motor assembly further includes a mechanical seal including a rotating ring and a fixed ring fixed to an inner wall of the third through hole, the rotating ring being fitted onto the rotating shaft and rotating together with the rotating shaft, and the fixed ring being fitted into the rotating ring and rotatably connected to the rotating ring.

8. An integrated electric drive system comprising the cooling structure of the integrated electric drive system according to any one of claims 1 to 7.

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