US-12627202-B2 - Power assembly and electric vehicle

Abstract

A power assembly includes a power component and a shell. The shell includes an accommodating structure, a flow diversion structure, a liquid storage structure, a heat dissipation structure, and a heat exchange structure. The accommodating structure is filled with cooling liquid. The flow diversion structure is configured to guide a flow direction of the cooling liquid. The liquid storage structure is configured to store the cooling liquid that is guided by the flow diversion structure to enter the liquid storage structure, and to distribute the cooling liquid that enters the liquid storage structure. The heat dissipation structure is configured to receive the cooling liquid distributed by the liquid storage structure, and to transfer the cooling liquid to the power component to cool the power component. The heat exchange structure is configured to perform heat exchange and cooling on the cooling liquid in the accommodating structure.

Inventors

• Haisong Xu
• Lingkun Zhu
• Yibo WANG

Assignees

• Huawei Digital Power Technologies Co., Ltd.

Dates

Publication Date

20260512

Application Date

20230824

Claims (20)

1. 1 . A power assembly, comprising: a power component comprising a stator disposed in a rotating shaft cavity and configured to drive cooling liquid to flow during rotation of the power component; and a shell comprising: an accommodating structure filled with the cooling liquid and rotatably disposing the power component; a flow diversion structure configured to guide a flow direction of the cooling liquid; a liquid storage structure configured to: receive the cooling liquid that is guided from the flow diversion structure; store the cooling liquid; and distribute the cooling liquid; a heat dissipation structure comprising: a spacer plate disposed on a top of the rotating shaft cavity and comprising a liquid guiding hole; and a stator heat dissipation groove in communication with the liquid storage structure and the accommodating structure, wherein the stator heat dissipation groove is configured to: receive the cooling liquid from the liquid storage structure; and transfer the cooling liquid to the stator through the liquid guiding hole for cooling the power component; and a heat exchange structure configured to: perform heat exchange on the cooling liquid in the accommodating structure; and perform cooling on the cooling liquid in the accommodating structure.
2. 2 . The power assembly of claim 1 , wherein the shell further comprises: a motor shell comprising the rotating shaft cavity; and a reducer shell connected to the motor shell, wherein the reducer shell comprises a gear cavity, and wherein the rotating shaft cavity and the gear cavity are in communication with each other and jointly form the accommodating structure.
3. 3 . The power assembly of claim 2 , wherein the spacer plate and the motor shell define the stator heat dissipation groove, and wherein the liquid guiding hole is in communication with the stator heat dissipation groove and the rotating shaft cavity.
4. 4 . The power assembly of claim 3 , wherein the spacer plate and the motor shell are integrated with each other.
5. 5 . The power assembly of claim 3 , wherein the shell further comprises a liquid storage plate that is disposed on a top of the gear cavity, wherein the liquid storage plate and the reducer shell define the liquid storage structure, and wherein the liquid storage structure is in communication with the stator heat dissipation groove.
6. 6 . The power assembly of claim 5 , wherein the liquid storage plate and the reducer shell are integrated with each other.
7. 7 . The power assembly of claim 5 , wherein the flow diversion structure is disposed in the gear cavity, wherein the liquid storage plate includes a liquid inlet hole disposed between a side of the liquid storage plate close to the flow diversion structure and the reducer shell, and wherein the liquid inlet hole is in communication with the liquid storage structure and the gear cavity.
8. 8 . The power assembly of claim 7 , wherein the flow diversion structure and the reducer shell are integrated with each other.
9. 9 . The power assembly of claim 3 , wherein the power component comprises: a rotor rotatably disposed in the stator; an input shaft comprising an end, wherein the input shaft is coaxially disposed on the rotor, and wherein the end is rotatably disposed in the reducer shell; an intermediate gear disposed in the gear cavity, wherein the intermediate gear comprises: an input gear; and an output gear, wherein the input gear and the output gear are coaxially disposed; an output shaft gear disposed in the gear cavity; and an input shaft gear disposed at the end of the input shaft that is disposed in the reducer shell, wherein the input gear and the input shaft gear are engaged with each other, wherein the output gear and the output shaft gear are engaged with each other, and wherein the flow diversion structure is configured to guide the cooling liquid to enter the liquid storage structure when raised by the intermediate gear or the output shaft gear.
10. 10 . The power assembly of claim 1 , wherein the heat exchange structure comprises: a heat exchange cavity in communication with the accommodating structure and disposed at a bottom of the accommodating structure; a cooling cavity formed at a bottom of the shell, wherein the cooling cavity surrounds the shell to form the heat exchange cavity; a water inlet pipe configured to allow inflow of cooling water, wherein the water inlet pipe is in communication with the cooling cavity; and a water outlet pipe configured to allow outflow of the cooling water, and wherein the water outlet pipe is in communication with the cooling cavity.
11. 11 . The power assembly of claim 10 , wherein the heat exchange structure further comprises cooling fins disposed in the cooling cavity, and wherein the cooling fins are configured to form, in the cooling cavity, a flow channel for allowing flow of the cooling water.
12. 12 . The power assembly of claim 1 , wherein the heat exchange structure further comprises cooling fins that are arranged at a bottom of the shell.
13. 13 . The power assembly of claim 9 , wherein the heat dissipation structure comprises: a rotor heat dissipation groove comprising: a first rotor heat dissipation groove end, wherein the first rotor heat dissipation groove end is in communication with the liquid storage structure; and a second rotor heat dissipation groove end in communication with the liquid guiding hole; and a mounting part disposed in the gear cavity, wherein the mounting part comprises a liquid guiding hole disposed in the mounting part, wherein the input shaft is rotatably disposed on the mounting part, wherein the input shaft further comprises a mounting hole and a heat dissipation cavity, wherein the mounting hole is axially disposed on the input shaft, and wherein the mounting part is disposed in the mounting hole.
14. 14 . The power assembly of claim 13 , further comprising a plate structure integrated with the reducer shell and defining the rotor heat dissipation groove.
15. 15 . The power assembly of claim 13 , further comprising a part disposed in the reducer shell that forms the rotor heat dissipation groove.
16. 16 . An electric vehicle, comprising: a battery configured to provide electric energy; and a power assembly configured to receive the electric energy, wherein the power assembly comprises: a power component comprising a stator disposed in a rotating shaft cavity and configured to drive cooling liquid to flow during rotation of the power component; and a shell comprising: an accommodating structure filled with cooling liquid and rotatably disposing the power component; a flow diversion structure configured to guide a flow direction of the cooling liquid to flow; a liquid storage structure configured to: receive the cooling liquid that is guided from the flow diversion structure; store the cooling liquid; and distribute the cooling liquid; a heat dissipation structure comprising: a spacer plate disposed on a top of the rotating shaft cavity and comprising a liquid guiding hole; and a stator heat dissipation groove in communication with the liquid storage structure and the accommodating structure, wherein the stator heat dissipation groove is configured to: receive the cooling liquid from the liquid storage structure; and transfer the cooling liquid to the stator through the liquid guiding hole for cooling the power component; and a heat exchange structure configured to: perform heat exchange on the cooling liquid in the accommodating structure; and perform cooling on the cooling liquid in the accommodating structure.
17. 17 . The electric vehicle of claim 16 , wherein the shell further comprises: a motor shell comprising the rotating shaft cavity; and a reducer shell connected to the motor shell, wherein the reducer shell comprises a gear cavity, and wherein the rotating shaft cavity and the gear cavity are in communication with each other and jointly form the accommodating structure.
18. 18 . The electric vehicle of claim 17 , wherein the spacer plate and the motor shell define the stator heat dissipation groove, and wherein the liquid guiding hole is in communication with the stator heat dissipation groove and the rotating shaft cavity.
19. 19 . The electric vehicle of claim 18 , wherein the spacer plate and the motor shell are integrated with each other.
20. 20 . The electric vehicle of claim 18 , wherein the shell comprises a liquid storage plate that is disposed on a top of the gear cavity, wherein the liquid storage plate and the reducer shell define the liquid storage structure, and wherein the liquid storage structure is in communication with the stator heat dissipation groove.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation application of International Patent Application No. PCT/CN2021/078274, filed on Feb. 26, 2021, which is hereby incorporated by reference in its entirety. TECHNICAL FIELD This application relates to the technical field of electric vehicles, and in particular, to a power assembly and an electric vehicle. BACKGROUND Different from a conventional oil-fueled automotive in which energy produced by combustion of fuel oil is used to drive an engine to make the fuel-fueled automotive move, a power source of an electric vehicle is a battery, and a power assembly including a motor is usually used to drive the electric vehicle. The motor in the power assembly of the electric vehicle is a power output core of the electric vehicle, and ensuring normal and stable operation of the motor is a key point of motor design. A heat loss of the motor during the operation includes a copper wire loss, an iron core loss, a windage loss, a stray loss, a mechanical loss, and the like. Generally, there are the following three modes for cooling a motor of an electric vehicle such as air cooling, water cooling, and oil cooling. An air cooling system uses wind generated by vehicle movement as a cooling medium, and a heat transfer path involves heat conduction between a motor and a motor shell and forced convection heat dissipation between the motor shell and air. Because the heat transfer path is long and a convection heat dissipation capability of the air is weak, the air cooling system is usually used only for a motor with relatively low heat productivity. A water cooling system uses a vehicle coolant as a cooling medium, and a heat transfer path involves heat conduction between a motor and a water-cooled jacket and forced convection heat dissipation between the water-cooled jacket and the coolant. Compared with the air, the coolant has a stronger forced convection heat dissipation capability. Therefore, an overall heat dissipation capability of the water cooling system is also stronger. However, because there is also additional thermal resistance of heat conduction, the water cooling system usually needs a relatively large heat exchange area. In the current modes for cooling a motor of an electric vehicle, the water cooling system is most widely applied. An oil cooling system uses a special insulating coolant or directly uses specially modulated transmission oil as a coolant, and a heat transfer path involves forced convection heat dissipation between a motor and cooling oil. Compared with the foregoing two cooling systems, due to direct contact between the coolant and a heat source, the oil cooling system has a strongest cooling capacity, can achieve more optimal performance through design, and can be used in a higher power density scenario. Usually, an oil-cooled electric drive system architecture mainly includes the following components such as an electric oil pump, a heat exchanger, and cooling structures in a stator and a rotor of a motor. The electric oil pump is configured to provide power for circulation of cooling oil. The heat exchanger is configured to dissipate heat from the system. The cooling structures designed in the stator and the rotor of the motor determine a heat exchange mode between the cooling oil and a heat source. A drive motor of an electric vehicle is developing in a direction of miniaturization, high speed, and low cost. For an electric drive assembly with small and medium power, the water cooling system cannot meet a heat dissipation requirement caused by increasing power density of a motor. However, because an electric oil pump and a heat exchanger are disposed, a conventional oil cooling system has relatively high costs and has no price advantage. SUMMARY In view of this, it is necessary to provide a power assembly and an electric vehicle, to effectively improve heat dissipation efficiency and reduce costs. According to a first aspect of embodiments of this application, a power assembly is provided, including a shell and a power component disposed in the shell. The shell includes an accommodating structure, a flow diversion structure, a liquid storage structure, a heat dissipation structure, and a heat exchange structure. The accommodating structure is filled with cooling liquid, and the power component is rotatably disposed in the accommodating structure, and can drive the cooling liquid in the accommodating structure to flow during rotation. The flow diversion structure is configured to guide a flow direction of the cooling liquid that is driven by the power component to flow. The liquid storage structure is configured to store the cooling liquid that is guided by the flow diversion structure to enter the liquid storage structure, and distribute the cooling liquid that enters the liquid storage structure. The heat dissipation structure is communicated with both the liquid storage structure and the accommodating structure, and the