Composite cooling structure of permanent magnet synchronous motor

Abstract

A composite cooling structure for a permanent magnet synchronous motor belongs to the technical field of permanent magnet synchronous motor cooling. The present invention addresses the problem that the existing permanent magnet synchronous motor has a single cooling method and poor heat dissipation effect. It comprises: a water cooling structure is arranged in the side wall of the motor casing, and the water cooling inlet and the water cooling outlet are correspondingly arranged on the upper end cover and the lower end cover of the motor casing; the oil cooling structure comprises an oil cooling unit at the upper end of the winding and an oil cooling unit at the lower end of the winding, the oil cooling unit at the upper end of the winding is arranged at a position corresponding to the upper end of the stator winding in the inner cavity of the motor casing; the oil cooling unit at the lower end of the winding is arranged at a position corresponding to the lower end of the stator winding in the inner cavity of the motor casing; the oil cooling unit at the upper end of the winding and the oil cooling unit at the lower end of the winding both cool the stator winding end through a circulating oil circuit structure; the heat conduction structure is arranged on the outer ring of the motor casing, and heat conduction of the heat in the motor casing is achieved through a circulating pipeline connecting the inside and outside of the motor casing. The present invention is used for motor cooling.

Description

Technical Field

[0001] The invention relates to a composite cooling structure of a permanent magnet synchronous motor, and belongs to the technical field of permanent magnet synchronous motor cooling. Background Art

[0002] Permanent magnet synchronous motors (PMSMs) use permanent magnets instead of field windings, reducing coil copper loss and significantly boosting power and torque density. However, their compact size and high power density can lead to excessively high operating temperatures, which negatively impact the motor. These include increasing the stator winding's resistivity, leading to increased motor losses; deteriorating winding insulation, resulting in short circuits between conductors and potentially causing motor breakdown, with serious consequences; and demagnetization of the permanent magnets once their temperature exceeds the permitted range. Therefore, effectively dissipating heat and cooling the PMSM and controlling the temperatures of its components within safe limits have become pressing challenges.

[0003] Motor cooling methods mainly include air cooling, water cooling, and oil cooling. The cooling method is usually selected based on the motor's capacity and operating conditions. For example, small-power motors mostly use air cooling, while high-power motors mostly use water cooling or oil cooling. For air cooling, the main aspects include the cooling medium and the cooling mode. Different cooling media have different characteristics. The cooling modes of air cooling include natural air cooling and forced air cooling. The appropriate air cooling mode needs to be selected based on a comprehensive evaluation and comparison of factors such as motor power and environment. For liquid cooling, the main aspects include the cooling medium and the cooling channel. Common cooling media include oil and water. Compared with water cooling, oil cooling is more expensive and has more requirements. The cooling channels of liquid cooling include spiral, circumferential, axial, and composite types. Selecting the appropriate cooling channel structure can improve cooling efficiency and reliability.

[0004] When designing a motor's cooling structure, the heat dissipation of the motor's various structural components is typically addressed, but the heat dissipation of the gas near the motor, such as the gas within the motor cavity and the gas near the motor casing, is rarely addressed. Generally speaking, the primary method for dissipating heat from the gas within the motor cavity is through forced air cooling via axial ventilation holes; the primary method for dissipating heat from the gas near the motor casing is through external forced air cooling. However, air cooling cannot, like liquid cooling, recycle the cooling liquid through a circulation structure after a single cooling cycle. This results in the motor consuming energy to provide forced air cooling every time it operates. Furthermore, liquid cooling cannot effectively avoid pressure problems caused by blockage of the cooling medium, nor insulation damage caused by leakage of the cooling medium, as air cooling can. Summary of the Invention

[0005] Aiming at the problem that the existing permanent magnet synchronous motor has a single cooling method and poor heat dissipation effect, the present invention provides a composite cooling structure for a permanent magnet synchronous motor.

[0006] The composite cooling structure of a permanent magnet synchronous motor of the present invention comprises a water cooling structure, an oil cooling structure and a heat conduction structure.

[0007] The water cooling structure is arranged in the side wall of the motor housing, and the water cooling inlet and the water cooling outlet are respectively arranged on the upper end cover and the lower end cover of the motor housing;

[0008] The oil cooling structure includes an oil cooling unit for the upper end of the winding and an oil cooling unit for the lower end of the winding. The oil cooling unit for the upper end of the winding is arranged at a position in the inner cavity of the motor housing corresponding to the upper end of the stator winding; the oil cooling unit for the lower end of the winding is arranged at a position in the inner cavity of the motor housing corresponding to the lower end of the stator winding. Both the oil cooling unit for the upper end of the winding and the oil cooling unit for the lower end of the winding cool the end of the stator winding through a circulating oil circuit structure.

[0009] The heat conduction structure is arranged on the outer ring of the motor casing, and heat conduction of the heat inside the motor casing is achieved through a circulation pipeline connecting the inside and outside of the motor casing.

[0010] According to the composite cooling structure of the permanent magnet synchronous motor of the present invention, the water cooling structure includes a spiral water channel, and the spiral water channel includes an upper vertical section, a spiral section and a lower vertical section.

[0011] The upper vertical section serves as a water cooling inlet and is connected to the water cooling source via the upper end cover of the motor casing, and the lower vertical section serves as a water cooling outlet and discharges the cooling liquid via the lower end cover of the motor casing; the spiral section between the upper vertical section and the lower vertical section is arranged in a spiral shape within the side wall of the motor casing.

[0012] According to the composite cooling structure of the permanent magnet synchronous motor of the present invention, there are four spiral water channels, which are arranged at 90° intervals in the side wall of the motor casing, and the spiral angle of the spiral section of each spiral water channel is 90°.

[0013] According to the composite cooling structure of the permanent magnet synchronous motor of the present invention, the upper end oil cooling unit includes an upper oil storage tray, an upper circulating oil circuit and an upper circulating oil cooling chamber;

[0014] The upper oil storage pan is located in the inner cavity of the motor casing, with the opening facing upward, and the bottom surface is in contact with the upper end surface of the stator core; the upper circulating oil cooling chamber is located above the upper end cover of the motor casing; an upper oil injector is arranged inside the upper circulating oil cooling chamber; the upper circulating oil circuit includes an upper oil injection pipeline and an upper oil return pipeline; the upper oil injection pipeline is located in the inner cavity of the motor casing, connecting the upper circulating oil cooling chamber and the upper oil storage pan; the upper oil return pipeline is located outside the motor casing, connecting the upper oil storage pan and the upper circulating oil cooling chamber; the upper oil injector sprays cooling oil to the upper end portion of the stator winding through the upper oil injection pipeline, and the cooling oil is finally stored in the upper oil storage pan and flows into the upper circulating oil cooling chamber through the upper oil return pipeline.

[0015] According to the composite cooling structure of the permanent magnet synchronous motor of the present invention, the oil cooling unit at the lower end of the winding comprises a lower oil storage pan, a lower circulating oil circuit and a lower circulating oil cooling chamber;

[0016] The lower oil storage pan is located in the inner cavity of the motor casing, with the opening facing upward, and the bottom surface is located below the lower end portion of the stator winding; the lower circulating oil cooling chamber is located below the lower end cover of the motor casing; a lower oil injector is arranged inside the lower circulating oil cooling chamber; the lower circulating oil circuit includes a lower oil injection pipeline and a lower oil return pipeline; the lower oil injection pipeline is located in the inner cavity of the motor casing, connecting the lower circulating oil cooling chamber and the lower oil storage pan; the lower oil return pipeline is located outside the motor casing, connecting the lower oil storage pan and the lower circulating oil cooling chamber; the lower oil injector sprays cooling oil to the lower end portion of the stator winding through the lower oil injection pipeline, and the cooling oil is finally stored in the lower oil storage pan and flows into the lower circulating oil cooling chamber through the lower oil return pipeline.

[0017] According to the composite cooling structure of the permanent magnet synchronous motor of the present invention, the heat conduction structure includes a heat circulation cavity and a heat circulation pipe. The heat circulation cavity is located below the lower end cover of the motor housing and has an interlayer cavity. The heat circulation pipe is arranged outside the motor housing and forms a circulation structure from the heat circulation cavity through the upper end cover of the motor housing, the upper oil storage pan, the lower oil storage pan, the lower end cover of the motor housing, and then to the heat circulation cavity.

[0018] According to the composite cooling structure of the permanent magnet synchronous motor of the present invention, the heat circulation pipes include 8 and are evenly distributed along the circumferential direction.

[0019] According to the composite cooling structure of the permanent magnet synchronous motor of the present invention, the upper oil storage pan and the lower oil storage pan are both circular ring structures with an annular cavity, and the inner diameter and outer diameter of the upper oil storage pan and the lower oil storage pan correspond to the inner diameter and outer diameter of the stator core.

[0020] According to the composite cooling structure of the permanent magnet synchronous motor of the present invention, both the upper injector and the lower injector have eight independent injection nozzles, which are evenly distributed along the circumferential direction.

[0021] According to the composite cooling structure of the permanent magnet synchronous motor of the present invention, a Freon-type refrigerant is arranged in the heat circulation pipe.

[0022] Beneficial effects of the present invention: The present invention combines the characteristics of liquid cooling and air cooling, comprehensively considers the heat dissipation effect of the motor, and proposes a composite cooling structure.

[0023] The present invention opens a water cooling structure on the casing shell and adopts a spiral structure to increase the flow path of cooling water; it can cool the end cover, casing and stator area of the permanent magnet synchronous motor; utilizes the non-magnetic and non-conductive properties of the cooling oil to make it directly contact the end of the motor winding, which can cool the stator winding and stator core of the permanent magnet synchronous motor; the heat conduction structure utilizes the low boiling point and high insulation properties of the cooling medium to cool the end of the permanent magnet synchronous motor and the gas near the motor casing; for the convection heat exchange between the end gas and the air gap gas caused by the rotation of the motor rotor part, the cooling medium in the heat conduction structure absorbs the heat of the end and boils and vaporizes, while also indirectly absorbing the heat of the air gap, which can cool the air gap of the permanent magnet synchronous motor; the oil cooling structure realizes the recycling of cooling oil through its circulation structure, and the heat conduction structure realizes the recycling of cooling medium through its circulation structure, which helps to save energy and improve resource utilization efficiency.

[0024] The present invention combines the advantages of various heat dissipation methods and combines them together to achieve effective heat dissipation of the motor. It is suitable for effectively cooling different types of motors and is suitable for popularization and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the overall structure of the composite cooling structure of the permanent magnet synchronous motor of the present invention;

[0026] Figure 2 yes Figure 1 Schematic diagram after removing the side wall of the motor casing;

[0027] Figure 3 It is a schematic diagram showing the arrangement of a water cooling structure on the side wall of a motor casing;

[0028] Figure 4 is a schematic diagram showing the upper end oil cooling unit 210;

[0029] Figure 5 is a schematic diagram showing the lower end oil cooling unit 220;

[0030] Figure 6 is a schematic diagram of the heat conduction structure 300 . DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0032] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0034] Specific implementation method 1. Combination Figures 1 to 6 As shown, the present invention provides a composite cooling structure for a permanent magnet synchronous motor, comprising a water cooling structure 100, an oil cooling structure and a heat conduction structure 300.

[0035] The water cooling structure 100 is arranged in the side wall of the motor housing, and the water cooling inlet and the water cooling outlet are respectively arranged on the upper end cover and the lower end cover of the motor housing;

[0036] The oil cooling structure includes an upper winding end oil cooling unit 210 and a lower winding end oil cooling unit 220. The upper winding end oil cooling unit 210 is arranged at a position corresponding to the upper end of the stator winding in the inner cavity of the motor housing; the lower winding end oil cooling unit 220 is arranged at a position corresponding to the lower end of the stator winding in the inner cavity of the motor housing. Both the upper winding end oil cooling unit 210 and the lower winding end oil cooling unit 220 cool the stator winding end through a circulating oil circuit structure.

[0037] The heat conduction structure 300 is arranged on the outer ring of the motor housing, and realizes heat conduction of the heat in the motor housing through a circulation pipeline connecting the inside and outside of the motor housing.

[0038] Further, combined Figure 2 and Figure 3 As shown, the water cooling structure 100 includes a spiral water channel, which includes an upper vertical section, a spiral section and a lower vertical section.

[0039] The upper vertical section serves as a water cooling inlet and is connected to the water cooling source via the upper end cover of the motor casing, and the lower vertical section serves as a water cooling outlet and discharges the cooling liquid via the lower end cover of the motor casing; the spiral section between the upper vertical section and the lower vertical section is arranged in a spiral shape within the side wall of the motor casing.

[0040] In this embodiment, a spiral water channel is opened on the casing, and the flow path of the cooling water is increased by the spiral structure.

[0041] As an example, there are four spiral water channels, which are arranged at intervals of 90° in the side wall of the motor housing, and the spiral angle of the spiral section of each spiral water channel is 90°.

[0042] Going further, combined Figures 1 to 2 and Figure 4 As shown, the upper end oil cooling unit 210 includes an upper oil storage pan, an upper circulating oil circuit and an upper circulating oil cooling chamber;

[0043] The upper oil storage pan is located in the inner cavity of the motor casing, with the opening facing upward, and the bottom surface is in contact with the upper end surface of the stator core; the upper circulating oil cooling chamber is located above the upper end cover of the motor casing; an upper oil injector is arranged inside the upper circulating oil cooling chamber; the upper circulating oil circuit includes an upper oil injection pipeline and an upper oil return pipeline; the upper oil injection pipeline is located in the inner cavity of the motor casing, connecting the upper circulating oil cooling chamber and the upper oil storage pan; the upper oil return pipeline is located outside the motor casing, connecting the upper oil storage pan and the upper circulating oil cooling chamber; the upper oil injector sprays cooling oil to the upper end portion of the stator winding through the upper oil injection pipeline, and the cooling oil is finally stored in the upper oil storage pan and flows into the upper circulating oil cooling chamber through the upper oil return pipeline.

[0044] Going a step further, combining Figures 1 to 2 and Figure 5 As shown, the winding lower end oil cooling unit 220 includes a lower oil storage pan, a lower circulating oil circuit and a lower circulating oil cooling chamber;

[0045] The lower oil storage pan is located in the inner cavity of the motor casing, with the opening facing upward, and the bottom surface is located below the lower end portion of the stator winding; the lower circulating oil cooling chamber is located below the lower end cover of the motor casing; a lower oil injector is arranged inside the lower circulating oil cooling chamber; the lower circulating oil circuit includes a lower oil injection pipeline and a lower oil return pipeline; the lower oil injection pipeline is located in the inner cavity of the motor casing, connecting the lower circulating oil cooling chamber and the lower oil storage pan; the lower oil return pipeline is located outside the motor casing, connecting the lower oil storage pan and the lower circulating oil cooling chamber; the lower oil injector sprays cooling oil to the lower end portion of the stator winding through the lower oil injection pipeline, and the cooling oil is finally stored in the lower oil storage pan and flows into the lower circulating oil cooling chamber through the lower oil return pipeline.

[0046] The upper and lower oil cooling units 210 and 220 are located in the cavity formed by the oil reservoir, the housing end cover, and the winding ends. Oil is sprayed onto the winding ends by an injector, removing heat from the stator windings and then stored in the reservoir. The oil then flows out through the cooling oil outlet valves at the ends to the circulating oil cooling chamber for cooling and recycling.

[0047] To ensure effective motor cooling, this embodiment incorporates oil cooling units at both the top and bottom of the motor windings. Considering that the cooling oil, after being sprayed out, flows downward under the action of gravity and comes into direct contact with the windings, it is necessary to ensure that the oil reservoirs in the oil injectors at the top and bottom ends of the motor windings are both open upward. Specifically, the bottom of the oil reservoir in the oil injectors at the top ends of the motor windings aligns with the stator core, while the bottom of the oil reservoir in the oil injectors at the bottom ends of the motor windings aligns with the end faces of the end windings. This prevents gravity from causing cooling oil to flow back and prevent it from flowing smoothly into the circulation structure.

[0048] The circulating oil cooling cavity can be fixed at a corresponding position of the end cover through interference fit.

[0049] Going further, combined Figure 6As shown, the heat conduction structure 300 includes a heat circulation cavity and a heat circulation pipe. The heat circulation cavity is located below the lower end cover of the motor housing and has an interlayer cavity. The heat circulation pipe is arranged outside the motor housing and passes through the heat circulation cavity in sequence through the upper end cover of the motor housing, the upper oil storage pan, the lower oil storage pan, the lower end cover of the motor housing, and then to the heat circulation cavity to form a circulation structure.

[0050] The heat circulation tube is connected to the housing via an interference fit. Considering that the cooling medium in the heat circulation tube is also affected by gravity, a pressure pump is also required for the heat circulation tube. Under the action of the pressure pump, the cooling medium flows along the heat circulation tube, passing through the lower end and upper end of the motor. After absorbing heat, it boils and vaporizes, ultimately entering the circulation section of the heat circulation tube as a vapor-liquid mixture.

[0051] As an example, the heat circulation tubes include 8 tubes, which are evenly distributed along the circumferential direction.

[0052] In this embodiment, the upper oil storage pan and the lower oil storage pan are both circular ring structures with an annular cavity. In order to ensure that the cooling oil and the winding end can fully contact each other under the premise of structural stability, the inner diameter and outer diameter of the upper oil storage pan and the lower oil storage pan are consistent with the inner diameter and outer diameter of the stator core.

[0053] For example, both the upper and lower injectors have eight independent nozzles, evenly distributed along the circumference. Considering the influence of gravity when the motor's bottom winding end injectors spray cooling oil onto the stator windings through their corresponding nozzles, and when the motor's top winding end injectors collect cooling oil into the circulation structure through their corresponding end oil outlets, additional pressure pumps are required for the motor's end winding injectors.

[0054] In this embodiment, the cooling structures are distributed at equal intervals along the circumferential direction, which can ensure uniform heat dissipation of the various structural parts of the motor.

[0055] In this embodiment, a Freon-based refrigerant is placed in the heat circulation pipe.

[0056] A low-boiling-point, high-insulation Freon-type product, F113, can be introduced into the heat circulation tube. This refrigerant will flow through the entire path of the heat circulation tube under the action of the pump. After absorbing heat from the winding ends, the air gap, and the air near the casing, the refrigerant will boil and vaporize, entering the circulation part of the heat circulation tube in a vapor-liquid mixed state, and finally entering the heat circulation cavity for cooling before being recycled.

[0057] In this embodiment, the upper and lower oil reservoirs can be made of Permalloy, leveraging its high magnetic permeability to minimize losses in the oil reservoirs. The heat circulation tube can be made of the same aluminum alloy as the housing, minimizing the contact thermal resistance between the tube and the housing. Contact thermal resistance refers to the presence of a tiny air gap between two solid surfaces when pressed together, resulting from machining and roughness limitations. The heat transfer performance of the gas filling this gap is very poor, and this is defined as additional contact thermal resistance.

[0058] The heat circulation cavity can be made of beryllium copper alloy material, which can ensure that the proper mechanical strength is maintained under the condition of volume increase caused by boiling and vaporization of the cooling medium due to its good fatigue resistance and elasticity.

[0059] The present invention realizes effective cooling of various structural parts inside the motor through the composite cooling structure, thereby solving the problems of poor heat dissipation and temperature rise of the permanent magnet synchronous motor.

[0060] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. It should be understood that many modifications may be made to the illustrative embodiments, and that other arrangements may be devised, without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in ways other than those described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in conjunction with other described embodiments.

Claims

1. A composite cooling structure for a permanent magnet synchronous motor, characterized in that: It comprises a water cooling structure (100), an oil cooling structure and a heat conduction structure (300), The water cooling structure (100) is arranged in the side wall of the motor housing, and the water cooling inlet and the water cooling outlet are correspondingly arranged on the upper end cover and the lower end cover of the motor housing; The oil cooling structure comprises an oil cooling unit (210) at the upper end of the winding and an oil cooling unit (220) at the lower end of the winding. The oil cooling unit (210) at the upper end of the winding is arranged at a position in the inner cavity of the motor housing corresponding to the upper end of the stator winding; the oil cooling unit (220) at the lower end of the winding is arranged at a position in the inner cavity of the motor housing corresponding to the lower end of the stator winding. Both the oil cooling unit (210) at the upper end of the winding and the oil cooling unit (220) at the lower end of the winding cool down the stator winding end through a circulating oil circuit structure. The heat conduction structure (300) is arranged on the outer ring of the motor housing and realizes heat conduction of the heat in the motor housing through a circulation pipeline connecting the inside and outside of the motor housing; The water cooling structure (100) includes a spiral water channel, which includes an upper vertical section, a spiral section and a lower vertical section. The upper vertical section serves as a water cooling inlet and is connected to a water cooling source via the upper end cover of the motor housing, and the lower vertical section serves as a water cooling outlet and discharges the cooling liquid via the lower end cover of the motor housing; The spiral section between the upper vertical section and the lower vertical section is arranged in a spiral shape inside the side wall of the motor housing; The upper end oil cooling unit (210) comprises an upper oil storage pan, an upper circulating oil circuit and an upper circulating oil cooling chamber; The upper oil storage pan is located in the inner cavity of the motor casing, with its opening facing upward, and its bottom surface is in contact with the upper end surface of the stator core; the upper circulating oil cooling chamber is located above the upper end cover of the motor casing; an upper oil injector is arranged inside the upper circulating oil cooling chamber; the upper circulating oil circuit includes an upper oil injection pipeline and an upper oil return pipeline; the upper oil injection pipeline is located in the inner cavity of the motor casing, connecting the upper circulating oil cooling chamber and the upper oil storage pan; the upper oil return pipeline is located outside the motor casing, connecting the upper oil storage pan and the upper circulating oil cooling chamber; the upper oil injector sprays cooling oil to the upper end of the stator winding through the upper oil injection pipeline, and the cooling oil is finally stored in the upper oil storage pan and flows into the upper circulating oil cooling chamber through the upper oil return pipeline; The winding lower end oil cooling unit (220) comprises a lower oil storage pan, a lower circulating oil circuit and a lower circulating oil cooling chamber; The lower oil storage pan is located in the inner cavity of the motor housing, with its opening facing upward and its bottom surface located below the lower end of the stator winding; the lower circulating oil cooling chamber is located below the lower end cover of the motor housing; a lower oil injector is arranged inside the lower circulating oil cooling chamber; the lower circulating oil circuit includes a lower oil injection pipeline and a lower oil return pipeline; the lower oil injection pipeline is located in the inner cavity of the motor housing and connects the lower circulating oil cooling chamber and the lower oil storage pan; the lower oil return pipeline is located outside the motor housing and connects the lower oil storage pan and the lower circulating oil cooling chamber; the lower oil injector sprays cooling oil to the lower end of the stator winding through the lower oil injection pipeline, and the cooling oil is finally stored in the lower oil storage pan and flows into the lower circulating oil cooling chamber through the lower oil return pipeline; The heat conduction structure (300) comprises a heat circulation cavity and a heat circulation pipe, wherein the heat circulation cavity is located below the lower end cover of the motor housing and has an interlayer cavity; The heat circulation pipe is arranged outside the motor casing and passes through the heat circulation cavity in sequence through the upper end cover of the motor casing, the upper oil storage pan, the lower oil storage pan, the lower end cover of the motor casing, and then to the heat circulation cavity to form a circulation structure; Freon refrigerant is configured in the heat circulation pipe.

2. The composite cooling structure of the permanent magnet synchronous motor according to claim 1, characterized in that: There are four spiral water channels, which are arranged at intervals of 90° in the side wall of the motor housing, and the spiral angle of the spiral section of each spiral water channel is 90°.

3. The composite cooling structure of the permanent magnet synchronous motor according to claim 1, characterized in that: The heat circulation pipes include 8 and are evenly distributed along the circumferential direction.

4. The composite cooling structure of the permanent magnet synchronous motor according to claim 1, characterized in that: The upper oil storage pan and the lower oil storage pan are both annular structures with an annular cavity, and the inner diameter and outer diameter of the upper oil storage pan and the lower oil storage pan correspond to the inner diameter and outer diameter of the stator core.

5. The composite cooling structure of the permanent magnet synchronous motor according to claim 1, characterized in that: Both the upper and lower injectors have 8 independent injection nozzles, which are evenly distributed along the circumference.

Images