Flow path assembly, electric drive assembly and vehicle

Abstract

A flow path assembly for an electric drive assembly includes a motor shaft rotatable about an axis of rotation including a first end and a second end opposite the first end; and the transmission shaft is in transmission connection with the motor shaft and is coaxially arranged with the motor shaft. The motor shaft includes a first center hole forming a portion of the flow path, and first and second cooling holes communicating with the first center hole. The first cooling hole is proximate the first end and the second cooling hole is proximate the second end. And a separation part is also arranged in the first central hole of the motor shaft, and divides the first central hole into a first section communicated with the first cooling hole and a second section communicated with the second cooling hole. The propeller shaft includes a second center hole forming a part of the flow path, and first and second communication holes, the first communication hole communicating the second center hole with the first section, and the second communication hole communicating the second center hole with the second section. The disclosure also relates to an electric drive assembly including the flow path assembly and a vehicle including the electric drive assembly.

Description

Technical Field

[0001] The present disclosure relates to a flow path assembly for an electric drive assembly, an electric drive assembly including such a flow path assembly, and a vehicle including such an electric drive assembly. Background Art

[0002] The electric drive assembly of a vehicle includes a motor for driving the vehicle and a transmission component such as a reduction gearbox. The motor shaft of the motor and the transmission shaft of the reduction gearbox are rotationally coupled to transfer torque from the motor to the reduction gearbox. For the sake of compactness and transmission efficiency, the motor and reduction gearbox of the electric drive assembly can be integrated together.

[0003] The motors used to drive vehicles usually have high power and generate a lot of heat when running continuously. If the heat dissipation is insufficient, the generated heat will accumulate inside the motor, causing the motor temperature to rise, affecting the reliability and performance of the motor. Oil-cooled motors can allow the cooling medium (cooling oil) to directly contact the internal components of the motor, so they have a better cooling effect and have been increasingly widely used in the vehicle field. Oil-cooled motors usually have cooling oil introduced into the motor shaft at the axis center of the motor, and the cooling oil is sprayed radially outward through the centrifugal force generated when the motor rotates to cool the various components of the motor.

[0004] The stator winding is a major heat-generating component of the motor, which usually includes ends extending beyond the stator body at the two axial ends of the motor. Therefore, it is desirable that the cooling oil entering the motor can be sprayed directly to the stator winding at the two axial ends of the motor to cool the winding. In the oil circuit of the integrated electric drive assembly, the motor is usually downstream of the reduction box, and the cooling oil flows from the transmission shaft of the reduction box into the motor shaft of the motor, and then sprayed radially outward at the two axial ends. This oil circuit is prone to uneven distribution of cooling oil at the two axial ends, that is, more cooling oil is sprayed to the axial end of the motor close to the reduction box, while relatively less cooling oil is sprayed to the axial end of the motor away from the reduction box. However, the heat generated by the stator winding at the two axial ends of the motor is approximately equal. This uneven distribution of cooling oil has caused the flow rate of cooling oil to be increased to meet the needs of the axial end of the motor away from the reduction box, resulting in an increase in cost.

[0005] Therefore, there is a need for a flow path assembly for an electric drive assembly, in which a cooling fluid, such as cooling oil, can be evenly distributed to two axial ends of a motor, thereby sufficiently cooling different parts of the motor. Summary of the invention

[0006] In response to the above-mentioned problems and needs, the present disclosure proposes a new type of flow path component for an electric drive assembly, which solves the above-mentioned problems and brings other technical effects by adopting the following technical features.

[0007] According to the present disclosure, a flow path component for an electric drive assembly includes: a motor shaft, which can rotate around a rotation axis, including a first end and a second end opposite to the first end; and a transmission shaft, which is transmission-connected to the motor shaft and arranged coaxially with each other. The motor shaft includes a first center hole forming a part of the flow path, and a first cooling hole and a second cooling hole connected to the first center hole, the first cooling hole is close to the first end, and the second cooling hole is close to the second end. A partition is also provided in the first center hole of the motor shaft, and the partition divides the first center hole into a first segment connected to the first cooling hole and a second segment connected to the second cooling hole. The transmission shaft includes a second center hole forming a part of the oil path, and a first connecting hole and a second connecting hole, the first connecting hole connecting the second center hole to the first segment, and the second connecting hole connecting the second center hole to the second segment.

[0008] One of the purposes of the present disclosure is to provide a flow path assembly for an electric drive assembly, wherein a cooling fluid, such as cooling oil, can be evenly distributed to the two axial ends of the motor, so as to fully cool different parts of the motor. According to the flow path assembly of the present disclosure, the first center hole of the motor shaft is divided into a first segment and a second segment by a partition, and the second center hole of the transmission shaft is connected to the first segment and the second segment through the first and second connecting holes, respectively. Thus, the cooling fluid can flow from the second center hole of the transmission shaft through the first and second connecting holes into the first segment and the second segment of the first center hole of the motor shaft, respectively, and then sprayed toward the two axial ends of the stator winding through the first cooling hole and the second cooling hole, respectively, under the action of centrifugal force. Under the action of the partition, the cooling fluid flowing into one of the first segment and the second segment will not flow into the other. Therefore, the proportion of the cooling fluid sprayed on the two axial ends of the stator winding can be accurately controlled, so that the cooling fluid can be evenly distributed, or the cooling fluid can be distributed in an uneven specific proportion when necessary.

[0009] The electric drive assembly according to the present disclosure may also have one or more of the following features alone or in combination.

[0010] According to one embodiment of the present disclosure, the transmission shaft is inserted into the first center hole of the motor shaft and extends over the partition. That is, the partition does not completely block the first center hole, but has a center hole for the transmission shaft to pass through. This structure of the flow path assembly facilitates the assembly between the motor shaft and the transmission shaft, and facilitates the communication between the second center hole of the transmission shaft and the first and second segments through the first and second communication holes.

[0011] According to an embodiment of the present disclosure, there is a certain radial spacing between the partition and the transmission shaft, so that the transmission shaft can conveniently extend over the partition.

[0012] According to one embodiment of the present disclosure, the first connecting hole and the second connecting hole are radial holes whose axial positions are located on both sides of the partition. Thus, the first connecting hole and the second connecting hole can be connected to the first segment and the second segment of the first central hole respectively. Optionally, the first connecting hole and the second connecting hole are arranged adjacent to the partition on both sides of the partition.

[0013] According to one embodiment of the present disclosure, the first communicating hole and / or the second communicating hole is an inclined hole forming a certain angle with the radial direction.

[0014] According to one embodiment of the present disclosure, the first connecting hole and the second connecting hole are connected to the second center hole at the same axial position. Thus, the cooling fluid flows from the second center hole to the first connecting hole and the second connecting hole at the same axial position. This can ensure that the cooling fluid flowing into the first connecting hole and the second connecting hole has the same fluid pressure, ensuring uniform distribution of the cooling fluid.

[0015] According to one embodiment of the present disclosure, the first connecting hole and the second connecting hole are connected to the second center hole at the axial position of the partition. Combined with the inclined structure of the first connecting hole and the second connecting hole, the first connecting hole and the second connecting hole can lead to the first segment and the second segment of the second center hole respectively.

[0016] According to an embodiment of the present disclosure, the first connecting hole and the second connecting hole are connected to the end of the second center hole. Thus, the length of the transmission shaft inserted into the first center hole required for the first and second connecting holes to connect the first and second segments respectively can be shortened as much as possible, reducing the difficulty of assembling the motor shaft and the transmission shaft.

[0017] According to an embodiment of the present disclosure, the diameter of the first communicating hole is equal to the diameter of the second communicating hole, or the diameter of the first communicating hole is different from the diameter of the second communicating hole.

[0018] According to one embodiment of the present disclosure, the partition is arranged close to the first end or the second end of the motor shaft.

[0019] According to one embodiment of the present disclosure, the partition portion is an annular partition rib extending from an inner wall of the first central hole of the motor shaft toward the center.

[0020] The present disclosure also relates to an electric drive assembly, which includes the flow path component as described above.

[0021] The present disclosure also relates to a vehicle, which includes the electric drive assembly as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other features and advantages of the present disclosure will become more apparent through the following detailed description of exemplary embodiments in conjunction with the accompanying drawings, and the description and drawings are only for illustrative purposes and are not intended to limit the scope of the present disclosure in any way. The following drawings are not deliberately drawn to scale with actual size, and the focus is on illustrating the subject matter of the present disclosure.

[0023] Figure 1 is a partial cross-sectional view of an electric drive assembly according to the present disclosure.

[0024] Figure 2 A cross-sectional view of a flow path assembly according to the present disclosure is schematically shown. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure.

[0026] Unless otherwise defined, the technical terms or scientific terms used herein shall be the common meanings understood by ordinary technicians in the field to which the present disclosure belongs. The words "one", "an" or "the" and the like used in the patent application specification and claims of the present disclosure do not indicate a quantity limitation, but indicate the existence of at least one. The words "include" or "include" and the like mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents. The words "connect" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. The terms "axial" and "axial direction" refer to the direction of the rotation axis X of the motor, and "radial" and "radial direction" refer to the direction perpendicular to the rotation axis X of the motor.

[0027] For the convenience of description, the drawings of the present disclosure simplify or omit components commonly used in the art, such as external connection lines and other components not related to the description of the present disclosure. These omitted or simplified components do not affect the understanding of the content of the present disclosure by those skilled in the art.

[0028] Figure 1 A partial cross-sectional view of an electric drive assembly according to an exemplary embodiment of the present disclosure is shown.

[0029] like Figure 1 As shown, the electric drive assembly includes a motor 100 and a transmission shaft 20, which can be, for example, an input shaft of a reduction gearbox. The motor 100 includes a rotor 110 and a stator 120. The motor shaft 10 is located at the axis of the rotor 110 and rotates around the rotation axis X together with the rotor 110. The transmission shaft 20 is coaxial with the motor shaft 10 of the motor 100 and is rotationally coupled so that there is no relative rotation between the motor shaft 10 and the transmission shaft 20. In other words, the rotation of the motor shaft 10 around the rotation axis X drives the transmission shaft 20 to rotate around the rotation axis X together, thereby achieving torque transmission from the motor 100 to the transmission shaft 20.

[0030] A cooling fluid circulates in the electric drive assembly, and the cooling fluid can cool various parts of the motor 100, and can also cool and / or lubricate other components such as the reduction gearbox. The flow path of the cooling fluid between the motor 100 and other components of the electric drive assembly is defined by the transmission shaft 20 and the motor shaft 10. When the cooling fluid flows, the motor 100 is usually located downstream of the transmission shaft 20, that is, the cooling fluid enters the motor 100 from the transmission shaft 20 through the motor shaft 10 of the motor 100. Figure 1 and Figure 2 , the transmission shaft 20 may be provided with a second center hole 21, and the motor shaft 10 may be provided with a first center hole 11. The transmission shaft 20 is inserted into the first center hole 11 of the motor shaft 10. Thus, the cooling fluid may flow from the second center hole 21 of the transmission shaft 20 into the first center hole 11 of the motor shaft 10. Then, the cooling fluid is sprayed from the motor shaft 10 in a radial direction under the driving of centrifugal force and reaches various components of the motor 100 to cool them.

[0031] Among the various components of the motor 100, the stator 120 includes a winding 121 in which a large alternating current flows, for generating an alternating magnetic field for driving the rotor 110 to rotate. Therefore, the winding 121 of the stator 120 is one of the main heat generating components of the motor 100. Figure 1 As shown, the winding 121 includes an end portion extending beyond the main body of the stator 120. When cooling the winding 121, optionally, a cooling fluid can be sprayed onto the end portion of the winding 121 and then flow axially to cool the entire winding 121.

[0032] refer to Figure 2As shown in the schematic diagram, the motor shaft 10 also includes a first cooling hole 12 and a second cooling hole 13 connected to the first center hole 11. The first cooling hole 12 and the second cooling hole 13 are respectively arranged at the first end 10a and the second end 10b of the motor shaft 10. The axial position of the first end 10a is relatively far away from the transmission shaft 20, which corresponds to the end of the winding 121 away from the transmission shaft 20. The second end 10b is opposite to the first end 10a and close to the transmission shaft 20, which corresponds to the end of the winding 121 close to the transmission shaft 20. Thus, the cooling fluid can be sprayed from the first center hole 11 of the motor shaft 10 through the first cooling hole 12 and the second cooling hole 13 to the two ends of the winding 121.

[0033] When the electric drive assembly is working, the cooling fluid flows from the second center hole 21 of the transmission shaft 20 into the first center hole 11 of the motor shaft 10. After that, the cooling fluid is first sprayed from the second cooling hole 13 close to the transmission shaft 20 toward the end of the winding 121 close to the transmission shaft 20, and then sprayed from the first cooling hole 12 away from the transmission shaft 20 toward the end of the winding 121 away from the transmission shaft 20. The first cooling hole 12 away from the transmission shaft 20 is usually arranged to be away from the entrance of the cooling fluid entering the first center hole 11 from the second center hole 21. In this way, the amount of cooling fluid sprayed from the first cooling hole 12 will be less than the amount of cooling fluid sprayed from the second cooling hole 13. However, when the motor 100 is working, the heat generation of the two ends of the winding 121 is basically the same. The difference in the amount of cooling fluid sprayed causes the cooling effect of different parts of the winding 121 to be different.

[0034] In order to solve the above problems, Figure 2 As shown, the motor shaft 10 of the present disclosure is provided with a partition 14 in the first center hole 11, and the partition 14 divides the first center hole 11 into a first segment 11a connected to the first cooling hole 12 and a second segment 11b connected to the second cooling hole 13. The transmission shaft 20 includes a first connecting hole 22 and a second connecting hole 23, wherein the first connecting hole 22 connects the second center hole 21 with the first segment 11a, and the second connecting hole 22 connects the second center hole 21 with the second segment 11b. The partition 14 can block the flow of the cooling fluid between the first segment 11a and the second segment 11b. As a result, the cooling fluid flowing into the first segment 11a through the first connecting hole 22 will only spray from the first cooling hole 12, while the cooling fluid flowing into the second segment 11b through the second connecting hole 23 will only spray from the second cooling hole 13. By regulating the amount of cooling fluid flowing out of the second central hole 21 through the first communicating hole 22 and the second communicating hole 23 , the amount of cooling fluid sprayed to the two ends of the winding 121 can be adjusted.

[0035] Optionally, the partition 14 has an annular form extending from the inner wall of the first center hole 11 of the motor shaft 10 toward the center, and does not completely block the first center hole 11, as long as it can block the flow of cooling fluid between the first segment 11a and the second segment 11b. The transmission shaft 20 extends over the partition 14 in the first center hole 11 of the motor shaft 10, and there is a certain radial spacing between the partition 14 and the transmission shaft 20. Figure 2 In the illustrated embodiment, the partition 14 is an annular partition rib extending from the inner wall of the first center hole 11 of the motor shaft 10 toward the center. When manufacturing the motor shaft 10, two sections of the motor shaft 10 can be manufactured first, and the two sections are welded together to form the motor shaft 10. The partition 14 is formed by an annular sheet embedded between the two sections during welding. Optionally, the two ends of the motor shaft 10 are welded together by friction welding, and the partition 14 is formed by a protrusion formed on the weld of the friction welding.

[0036] The partition 14 is close to the second end 10b of the motor shaft 10. In this way, the transmission shaft 20 can pass over the partition 14 by inserting a small length into the first center hole 11, which reduces the difficulty of assembling the transmission shaft 20 and the motor shaft 10. It should be understood that the partition 14 can also be arranged close to the first end 10a of the motor shaft 10. In this case, the transmission shaft 20 needs to be inserted into the first center hole 11 with a larger length before it can pass over the partition 14.

[0037] For the motor 100 with substantially the same heat generation at both ends of the winding 121, it is optional to make the amount of cooling fluid sprayed from the first cooling hole 12 and the second cooling hole 13 substantially equal. To this end, the transmission shaft 20 is constructed so that the axial positions of the first connecting hole 22 and the second connecting hole 23 connected to the second center hole 21 are close to or the same, so that the cooling fluid flows out of the first connecting hole 22 and the second connecting hole 23 at the same fluid pressure. Figure 2 In the example shown, the first communicating hole 22 and the second communicating hole 23 are inclined holes at a certain angle to the radial direction, and both are connected to the second center hole 21 at the same axial position. Optionally, the first communicating hole 22 and the second communicating hole 23 are connected to the second center hole 21 at the axial position of the partition 14. The inclined configuration of the first communicating hole 22 and the second communicating hole 23 makes it possible to reduce the length of the transmission shaft 20 extending over the partition 14, while ensuring that the cooling fluid flowing out of the first communicating hole 22 enters the first segment 11a, and the cooling fluid flowing out of the second communicating hole 23 enters the second segment 11a. The first communicating hole 22 and the second communicating hole 23 can also be connected to the end of the second center hole 21 to further reduce the length of the transmission shaft 20.

[0038] In an optional embodiment not shown, the first communicating hole 22 and the second communicating hole 23 may also be radial holes, whose axial positions are respectively located on both sides of the partition 14 to lead to the first segment 11a and the second segment 11b respectively. The first communicating hole 22 and the second communicating hole 23 may be arranged close to the partition 14, for example, adjacent to the partition 14 on both sides.

[0039] exist Figure 2 In the example shown, the diameters of the first connecting hole 22 and the second connecting hole 23 are equal, and the diameters of the first cooling hole 12 and the second cooling hole 13 are also equal. This helps to spray approximately equal amounts of cooling fluid to the two ends of the winding 121. Of course, in the case where unequal amounts of cooling fluid need to be sprayed toward the two ends of the winding 121, the diameters of the first connecting hole 22 and the second connecting hole 23 may be unequal, and the diameters of the first cooling hole 12 and the second cooling hole 13 may also be unequal.

[0040] According to another aspect of the present disclosure, a vehicle is provided, which includes an electric drive assembly as described above. The vehicle may be an electrified vehicle, such as a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), an extended range electric vehicle (Range extended EV), or a fuel cell vehicle (FCEV). The vehicle may also be a hydrogen energy vehicle.

[0041] Certain features, structures or characteristics in one or more embodiments of the present disclosure may be appropriately combined.

[0042] The above is an explanation of the present disclosure and should not be considered as a limitation thereof. Although several exemplary embodiments of the present disclosure are described, it will be readily appreciated by those skilled in the art that many modifications may be made to the exemplary embodiments without departing from the novel teachings and advantages of the present disclosure. Therefore, all such modifications are intended to be included within the scope of the present disclosure as defined in the claims. It should be understood that the above is an explanation of the present disclosure and the present disclosure should not be considered to be limited to the specific embodiments disclosed, and modifications to the disclosed embodiments and other embodiments are intended to be included within the scope of the present disclosure.

Claims

1. A flow path component for an electric drive assembly, characterized in that: The flow path assembly comprises a motor shaft (10) rotatable about a rotation axis (X), comprising a first end (10a) and a second end (10b) opposite to the first end; and A transmission shaft (20) is transmission-connected to the motor shaft (10) and arranged coaxially with each other. The motor shaft (10) comprises a first central hole (11) forming a part of a flow path, and a first cooling hole (12) and a second cooling hole (13) communicating with the first central hole (11), the first cooling hole (12) being close to the first end (10a), and the second cooling hole (13) being close to the second end (10b), A partition (14) is further provided in the first central hole (11) of the motor shaft (10), wherein the partition (14) divides the first central hole (11) into a first segment (11a) communicating with the first cooling hole (12) and a second segment (11b) communicating with the second cooling hole (13), and The transmission shaft (20) includes a second center hole (21) forming a part of the flow path, and a first connecting hole (22) and a second connecting hole (23), wherein the first connecting hole (22) connects the second center hole (21) with the first segment (11a), and the second connecting hole (22) connects the second center hole (21) with the second segment (11b).

2. The flow path assembly according to claim 1, characterized in that: The transmission shaft (20) is inserted into the first central hole (11) of the motor shaft (10) and extends over the partition (14).

3. The flow path assembly according to claim 2, characterized in that: There is a certain radial spacing between the partition (14) and the transmission shaft (20).

4. The flow path component according to claim 2 or 3, characterized in that: The first communicating hole (22) and the second communicating hole (23) are radial holes located axially on both sides of the partition (14).

5. The flow path component according to claim 2 or 3, characterized in that: The first connecting hole (22) and / or the second connecting hole (23) are inclined holes that form a certain angle with the radial direction.

6. The flow path assembly according to claim 5, characterized in that: The first communicating hole (22) and the second communicating hole (23) are connected to the second center hole (21) at the same axial position.

7. The flow path assembly according to claim 6, characterized in that: The first communicating hole (22) and the second communicating hole (23) are connected to the second center hole (21) at an axial position of the partition portion (14).

8. The flow path assembly according to claim 6, characterized in that: The first communicating hole (22) and the second communicating hole (23) are connected to the end of the second center hole (21).

9. The flow path assembly according to claim 2, characterized in that: The diameter of the first communicating hole (22) and the diameter of the second communicating hole (23) are equal, or the diameter of the first communicating hole (22) and the diameter of the second communicating hole (23) are different.

10. The flow path assembly according to any one of claims 1 to 3, characterized in that: The partition (14) is arranged close to the first end (10a) or the second end (10b) of the motor shaft (10).

11. The flow path assembly according to any one of claims 1 to 3, characterized in that: The partition (14) is an annular partition rib extending from the inner wall of the first central hole (11) of the motor shaft (10) toward the center.

12. An electric drive assembly, characterized in that: The electric drive assembly comprises a flow path assembly according to any one of claims 1 to 11.

13. A vehicle, characterized in that: The vehicle includes the electric drive assembly according to claim 12.

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