Motor cooling system, permanent magnet synchronous motor and vehicle

Abstract

The utility model relates to a motor cooling system, a permanent magnet synchronous motor and a vehicle. The cooling system comprises a motor housing, a stator, a rotor, a water cooling unit and an oil cooling unit. The water cooling unit comprises an outer-layer water path and an inner-layer water path which are arranged on the motor shell; the oil cooling unit comprises a heat exchange oil way, a first oil groove, a second oil groove, a center oil way and a radial oil way, the heat exchange oil way is arranged between the outer-layer water way and the inner-layer water way; the first oil groove is circumferentially arranged along the outer diameter of the stator core, and the second oil groove is arranged at the axial end part of the first oil groove and communicated with the first oil groove; the central oil way and the radial oil way are both arranged in a main shaft of the rotor and are communicated with each other, and the radial oil way is opened on the outer surface of the main shaft and is used for cooling the bearing, the inner surface of the winding and the rotor iron core.

Description

TECHNICAL FIELD

[0001] The utility model relates to motor cooling technical field especially relates to a motor cooling system, permanent magnet synchronous motor and vehicle. BACKGROUND

[0002] With the rapid development of new energy vehicles, the permanent magnet synchronous motor as its core component is developing towards miniaturization and high power density.

[0003] In the motor operation process, due to the continuous improvement of winding current density and whole machine power density requirement, the motor structure is increasingly compact, which leads to the rapid rise of motor winding temperature and working temperature, and the temperature rise will bring many negative effects: on the one hand, the resistivity of stator winding gradually increases, causing the motor loss to increase, on the other hand, the winding insulation layer fails, leading to short circuit between wires, so that the motor exists the risk of breakdown, at the same time, once the temperature of permanent magnet exceeds the allowable temperature range, demagnetization phenomenon will occur. Therefore, effectively cooling and cooling the permanent magnet synchronous motor to control the temperature of each part of the motor within the safe range has become a technical problem to be solved.

[0004] At present, the end winding of the stator oil immersion cooling motor usually adopts the way of oil complete immersion or top installation of oil spraying ring for cooling. However, these cooling methods all have obvious deficiencies: in the complete immersion mode, due to the small space of the end part, the cooling oil flows slowly in the cavity, the convection heat transfer of the fluid-solid interface is poor, which leads to that the end winding is not fully cooled; in the top oil spraying mode, the cooling medium can only contact the outer surface of the end winding, and the end inner side and the center part winding which have worse heat dissipation condition are difficult to be effectively cooled.

[0005] Some improvement schemes appear in the prior art, such as adopting special winding oil spraying ring structure, improving the cooling effect of the end winding by setting circumferential and axial oil spraying holes on the side surface of the oil spraying tooth, but this structure design inevitably leads to the increase of the size of the stator winding end part, and further makes the motor axial size grow and the whole machine weight increase, which is contrary to the development requirements of motor miniaturization and high power density.

[0006] Therefore, how to realize the effective cooling of the inner and outer surfaces of the end part of the motor stator winding without increasing the axial size of the motor, and improve the heat exchange efficiency at the same time, has become a technical problem to be solved in the field. UTILITY MODEL CONTENTS

[0007] The utility model discloses a motor cooling system, permanent magnet synchronous motor and vehicle, aims at solving the technical problems existing in the prior art.

[0008] The utility model adopts the following technical scheme:

[0009] On the one hand, this utility model embodiment provides a motor cooling system, including a motor housing, stator, rotor, water cooling unit and oil cooling unit;

[0010] The water-cooling unit includes an outer water channel and an inner water channel disposed on the motor housing;

[0011] The oil cooling unit includes a heat exchange oil circuit and a first oil tank, a second oil tank, a central oil circuit, and a radial oil circuit connected to it;

[0012] The heat exchange oil passage is located between the outer water passage and the inner water passage;

[0013] The first oil groove is arranged circumferentially along the outer diameter of the stator core of the stator, and the second oil groove is arranged at the axial end of the first oil groove and communicates with it;

[0014] Both the central oil passage and the radial oil passage are located inside the rotor's main shaft and are connected. The radial oil passage is open on the outer surface of the main shaft and is used to cool the bearings, the inner surface of the windings, and the rotor core.

[0015] As a preferred technical solution, the outer water channel and the inner water channel are both arranged in a U-shape on the motor housing and are connected to each other. The motor housing is provided with a water inlet and a water outlet, and the water inlet and the water outlet are connected to the outer water channel and the inner water channel.

[0016] As a preferred technical solution, the heat exchange oil circuit is arranged in a U-shape, and the motor housing is provided with an oil inlet and an oil outlet, with the oil inlet connected to the heat exchange oil circuit.

[0017] The motor housing has end caps at both ends. The oil cooling unit also includes an end cap oil passage on the end cap, an oil cavity inside the motor housing, and a first housing oil passage cavity and a second housing oil passage cavity on the inner wall of the motor housing.

[0018] The heat exchange oil circuit is connected to the first outer shell oil circuit cavity through the first connecting passage, and the heat exchange oil circuit is connected to the second outer shell oil circuit cavity through the second connecting passage. The second outer shell oil circuit cavity extends axially and is connected to the end cover oil circuit.

[0019] The oil chamber is connected to the oil outlet and is used to collect the returned oil.

[0020] As a preferred technical solution, the second oil tank includes a first set of sub-oil tanks and a second set of sub-oil tanks, both of which are evenly arranged along the circumference of the stator core.

[0021] The first set of sub-oil grooves extends axially, and the second set of sub-oil grooves extends obliquely at a first preset angle. The second set of sub-oil grooves penetrates the stator core and is used to spray cooling medium onto the outer surface of the end of the stator winding.

[0022] As a preferred technical solution, the oil cooling unit also includes a shaft end oil passage, the two ends of which are connected to the end cover oil passage and the center oil passage, respectively.

[0023] As a preferred technical solution, the radial oil passage includes a first radial oil passage for cooling the bearing, a second radial oil passage for cooling the inner surface of the winding, and a third radial oil passage for cooling the rotor core.

[0024] The central oil passage is arranged axially inside the spindle. The first radial oil passage includes a first bearing cooling oil passage and a second bearing cooling oil passage. Both the first bearing cooling oil passage and the second bearing cooling oil passage are evenly arranged circumferentially along the spindle.

[0025] A second preset angle is provided between the first bearing cooling oil passage and the central oil passage, and a third preset angle is provided between the second bearing cooling oil passage and the central oil passage.

[0026] As a preferred technical solution, the second radial oil passage is uniformly arranged along the circumference of the main shaft. The second radial oil passage includes a first winding inner surface cooling oil passage and a second winding inner surface cooling oil passage located at both ends of the main shaft. The first winding inner surface cooling oil passage and the second winding inner surface cooling oil passage are respectively located at the two ends of the corresponding stator winding.

[0027] As a preferred technical solution, the oil cooling unit also includes several rotor core cooling oil passages, which are arranged along the circumference of the rotor core. The rotor core cooling oil passages are connected to the third radial oil passage in a one-to-one correspondence. The rotor core cooling oil passages are used to spray the cooling medium into the rotor core.

[0028] Secondly, this utility model provides a permanent magnet synchronous motor, including the motor cooling system as described in any of the preceding claims.

[0029] Thirdly, this utility model embodiment provides a vehicle including the permanent magnet synchronous motor described above.

[0030] One embodiment of the above-described utility model has the following advantages or beneficial effects:

[0031] This invention provides a motor cooling system suitable for permanent magnet synchronous motors. Compared with existing technologies, this invention integrates a water-cooling unit and an oil-cooling unit within the motor, forming a dual water-oil cooling system. This fully utilizes the efficient heat dissipation characteristics of water cooling and leverages the direct cooling effect of oil cooling on the internal structures of the motor. Without increasing the existing axial dimensions of the motor, it significantly improves the overall heat dissipation efficiency of the motor. It also replaces the oil-water heat exchanger, eliminating redundant structures in the electric drive system, and has a significant effect on improving the winding current density and power density of the motor.

[0032] Specifically, this utility model adopts a multi-layer nested water and oil circuit structure, which maximizes the coverage of the motor housing surface by the flow path of the cooling medium, and achieves a reasonable distribution of the cooling medium in the radial and axial directions, ensuring the uniformity and stability of heat dissipation.

[0033] By setting an adjustable oil groove group in the stator core, combined with a multi-stage radial oil circuit system in the rotor spindle, the stator core, stator winding, rotor core and bearings can be cooled simultaneously, effectively solving the problem of local overheating inside the motor. While ensuring the cooling effect, it saves installation space to the greatest extent and improves the system integration. It has significant effects on improving the motor's overload capacity, miniaturization and weight reduction, and is especially suitable for application scenarios such as new energy vehicles that have strict requirements for space and heat dissipation performance.

[0034] In addition, the motor cooling system of this utility model has good reliability and maintainability. Each cooling unit is relatively independent yet works together. Even if a single cooling circuit fails, it can still maintain basic cooling function, thus improving the overall fault tolerance and safety of the system. Attached Figure Description

[0035] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below, forming part of this utility model. The illustrative embodiments of this utility model and their descriptions explain this utility model and do not constitute an improper limitation of this utility model. In the accompanying drawings:

[0036] Figure 1 This is a schematic diagram of the structure of a motor cooling system disclosed in a preferred embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of the structure of the motor housing disclosed in a preferred embodiment of the present invention;

[0038] Figure 3 This is a cross-sectional view of the motor housing disclosed in a preferred embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of the structure of a water-cooling unit disclosed in a preferred embodiment of the present invention;

[0040] Figure 5 This is a schematic diagram of the heat exchange oil circuit disclosed in a preferred embodiment of the present invention;

[0041] Figure 6 This is a cross-sectional view of a motor cooling system disclosed in a preferred embodiment of the present invention;

[0042] Figure 7This is a cross-sectional view of the motor cooling system disclosed in a preferred embodiment of the present invention from another angle.

[0043] Figure 8 This is a partially enlarged view of the stator core disclosed in a preferred embodiment of the present invention;

[0044] Figure 9 This is a schematic diagram of the main shaft disclosed in a preferred embodiment of the present invention;

[0045] Figure 10 This is a cross-sectional view of the main shaft disclosed in a preferred embodiment of the present invention;

[0046] Figure 11 This is a cross-sectional view of the main shaft disclosed in a preferred embodiment of the present invention;

[0047] Figure 12 This is a schematic diagram of the rotor core disclosed in a preferred embodiment of the present invention.

[0048] Explanation of reference numerals in the attached figures:

[0049] Motor housing 100, water inlet 110, water outlet 120, outer water channel 130, inner water channel 140, oil inlet 150, oil outlet 160, heat exchange oil channel 170, first housing oil channel cavity 171, second housing oil channel cavity 172, oil cavity 180, left end cover 200, right end cover 300, end cover oil channel 310, stator core 400, first oil groove 410, first set of sub-oil grooves 420, second set of sub-oil grooves 430, main shaft 500, shaft end oil channel 510, center oil channel 520, first bearing cooling oil channel 530, second bearing cooling oil channel 540, first winding inner surface cooling oil channel 550, second winding inner surface cooling oil channel 560, third radial oil channel 570, rotor core 600, rotor core cooling oil channel 610, permanent magnet 700. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. In the description of this utility model, it should be noted that the term "or" is generally used to include the meaning of "and / or," unless otherwise expressly stated otherwise.

[0051] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or a magnetic connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Furthermore, in the description of this application, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0052] Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0053] With the development of new energy vehicle technology, the power density of automotive permanent magnet synchronous motors is constantly increasing. When the motor is running at high speed, uneven heat dissipation is likely to occur in local areas such as the stator winding ends, permanent magnets, and rotor core. Although the existing oil cooling solution can achieve local cooling inside the motor, the overall heat dissipation efficiency is low, or it may lead to an increase in the axial dimension and weight of the motor, which seriously restricts the improvement of motor performance.

[0054] refer to Figure 1 , Figure 6 , Figure 7 In a preferred embodiment, the permanent magnet synchronous motor includes a motor housing 100, with a left end cover 200 and a right end cover 300 at its ends. Inside, there is a stator and a rotor. The stator includes a stator core 400 and stator windings disposed on the stator core 400. The stator windings have ends extending out of the stator core 400; in this embodiment, these are defined as winding ends. The rotor includes a main shaft 500, a rotor core 600, and permanent magnets 700 disposed within the rotor core 600. The main shaft 500 cooperates with bearings to allow the rotor to rotate relative to the stator. During motor operation, the stator windings are energized to generate a rotating magnetic field, which drives the rotor with the permanent magnets 700 to rotate, thereby realizing the conversion of electrical energy into mechanical energy.

[0055] During high-speed operation of the motor, components such as the stator windings, permanent magnets 700, and rotor core 600 generate a large amount of heat. If this heat cannot be dissipated in time, the temperature of various components of the motor will rise rapidly, affecting the operating efficiency and service life of the motor. To solve this problem, in a preferred embodiment of this utility model, a motor cooling system suitable for permanent magnet synchronous motors is provided. This system can perform oil spray cooling on the ends of the stator windings and water cooling on the motor housing 100 without increasing the axial dimension of the motor. At the same time, heat exchange is carried out during the oil-water circulation cooling process, improving the heat exchange efficiency and cooling effect of the motor, thereby increasing the stator winding current density and the power density of the motor.

[0056] like Figure 1 In a preferred embodiment, the motor cooling system includes a motor housing 100, a stator, a rotor, a water-cooling unit, and an oil-cooling unit. The motor housing 100 has a left end cover 200 and a right end cover 300 at both ends. The stator and rotor are encapsulated within the motor housing 100. The water-cooling unit is disposed on the motor housing 100, and the oil-cooling unit is disposed within the motor housing 100, the stator, and the rotor. It should be noted that the motor cooling system in this embodiment is closely integrated with the basic structure of the permanent magnet synchronous motor. The motor housing 100 is both the basic support structure of the permanent magnet synchronous motor and an important component of the cooling system, used to arrange the flow channels for the water-cooling and oil-cooling units. The right end cover 300 not only supports the bearings but also contains part of the channel for the oil-cooling unit. The stator and rotor are each provided with specific structures for the oil-cooling unit. These structures, combined with the motor body, form a highly integrated cooling system, which can ensure cooling effect while avoiding space waste caused by external cooling devices.

[0057] refer to Figure 1 — Figure 4 In a preferred embodiment, the water-cooling unit includes an outer water channel 130 and an inner water channel 140 arranged circumferentially along the motor housing 100. Both are arranged in a U-shape and are interconnected. This U-shaped structure allows the cooling water to flow back and forth along the axial direction of the motor housing 100, extending the contact time between the cooling water and the motor housing 100. The motor housing 100 is provided with an inlet 110 and an outlet 120, both of which are connected to the outer water channel 130 and the inner water channel 140. The cooling water introduced through the inlet 110 first enters the outer water channel 130, passes through the U-shaped channel, enters the inner water channel 140, and finally flows out from the outlet 120, forming a complete water circulation system.

[0058] Preferably, in order to increase the heat exchange area of ​​water cooling, multiple sets of outer water channels 130 and inner water channels 140 are arranged along the circumference of the motor housing 100, and adjacent sets of water channels are connected by connecting sections to ensure uniform heat dissipation of the motor housing 100 by water cooling and avoid the generation of local hot spots.

[0059] like Figure 5 — Figure 7 Preferably, the oil cooling unit includes a heat exchange oil passage 170 disposed on the motor housing 100. The heat exchange oil passage 170 is disposed between the outer water passage 130 and the inner water passage 140. The heat exchange oil passage 170 is also arranged in a U-shape. This sandwich layout allows the heat exchange oil passage 170 to fully exchange heat with the water passage, thereby improving the cooling effect of the oil cooling medium.

[0060] Preferably, the motor housing 100 is provided with an oil inlet 150 and an oil outlet 160. The oil inlet 150 is connected to the heat exchange oil passage 170. The cooling oil introduced through the oil inlet 150 is first pre-cooled through the heat exchange oil passage 170 to reduce its temperature before entering the subsequent oil passage of the oil cooling unit. Preferably, the oil cooling unit also includes an oil chamber 180 disposed inside the outer casing. The oil chamber 180 is connected to the oil outlet 160 and is used to collect the cooling oil flowing out from various parts of the stator and rotor and discharge it. The oil chamber 180 is preferably disposed at the bottom of the motor housing 100 to achieve natural collection of cooling oil by gravity, thereby improving the oil return efficiency.

[0061] like Figure 3 Preferably, each set of outer water channels 130 corresponds one-to-one with each set of inner water channels 140 in the radial direction. Multiple sets of heat exchange oil channels 170 are also provided along the circumference of the motor housing 100, with each set of heat exchange oil channels 170 positioned between one set of outer water channels 130 and one set of inner water channels 140 to ensure a tight fit between the heat exchange oil channels 170 and the water channels, improving heat exchange efficiency. This also makes the entire cooling system structure more compact and symmetrical, facilitating system assembly and maintenance. Through the synergistic effect of the inner water channels 140, outer water channels 130, and heat exchange oil channels 170, efficient heat dissipation is achieved in the motor housing 100.

[0062] In a preferred embodiment, each set of outer water channels 130, inner water channels 140, and heat exchange oil channels 170 has certain dimensions in both the axial and circumferential directions. Optionally, in the axial direction, the length of the outer water channels 130, inner water channels 140, and heat exchange oil channels 170 substantially covers the effective length of the motor housing 100 to ensure sufficient cooling of the motor body. In the circumferential direction, the width of each set of inner water channels 140, outer water channels 130, and heat exchange oil channels 170 is approximately 1 / 6, 1 / 8, or other proportions of the circumferential dimension of the motor housing 100, allowing for the uniform arrangement of the outer water channels 140 and heat exchange oil channels 170 in the circumferential direction of the motor housing 100. By rationally setting the dimensions of the water channels and heat exchange oil channels 170 in the axial and circumferential directions, sufficient heat exchange area is ensured, and sufficient heat exchange between the cooling medium and the motor housing 100 is achieved, thereby improving the heat exchange efficiency of the entire cooling system.

[0063] It should be noted that those skilled in the art can make adaptive adjustments to parameters such as the type of pipe material, the size of the inner water passage 140, the outer water passage 130, and the heat exchange oil passage 170 according to actual application scenarios, such as the specific model of the motor, power level, heat dissipation requirements, and installation space. As long as the heat dissipation requirements of the motor can be met, no specific limitation is made in this embodiment.

[0064] like Figure 5 , Figure 7 In a preferred embodiment, the cooling oil pre-cooled by the heat exchange oil circuit 170 enters the structure of the oil cooling unit disposed in the stator and rotor through two different connection passages. The heat exchange oil circuit 170 is connected to the first housing oil circuit cavity 171 disposed in the inner wall of the motor housing 100 through the first connection passage. The first housing oil circuit cavity 171 is connected to the stator and is used for cooling the stator. The heat exchange oil circuit 170 is connected to the second housing oil circuit cavity 172 disposed in the inner wall of the motor housing 100 through the second connection passage. The second housing oil circuit cavity 172 extends axially to the right end cover 300 and communicates with the end cover oil circuit 310 disposed on the right end cover 300. Finally, the cooling oil is transported to the rotor through the end cover oil circuit 310.

[0065] like Figure 6 — Figure 8In a preferred embodiment, the oil cooling unit is provided with a first oil groove 410 and a second oil groove in the stator. The first oil groove 410 is arranged circumferentially around the outer diameter of the stator core 400, preferably at the middle position of the outer diameter of the stator core 400. The first oil groove 410 is connected to the first outer shell oil passage cavity 171. A plurality of second oil grooves are arranged at the axial ends of the first oil groove 410 and are arranged circumferentially. The two are interconnected and are used to transport cooling oil to the second oil groove. The second oil groove includes a first group of sub-oil grooves 420 and a second group of sub-oil grooves 430. Both are evenly arranged circumferentially around the stator core 400. The first group of sub-oil grooves 420 extends axially, and the second group of sub-oil grooves 430 extends obliquely. A first preset included angle α1 is provided between the first group of sub-oil grooves 420 and the second group of sub-oil grooves 430. The second group of sub-oil grooves 430 penetrates the stator core 400 and is used to spray cooling oil over a large area onto the outer surface of the winding end.

[0066] Preferably, the first preset included angle α1 is adapted to the winding end height and / or the pressure of the cooling medium, so as to make the cooling medium sprayed along a predetermined trajectory to the outer surface of the stator winding end.

[0067] Specifically, when the height of the winding end is large, the value of the first preset angle α1 can be increased accordingly so that the cooling oil can cover the surface of the winding end at a higher position; when the height of the winding end is small, the first preset angle α1 can be decreased accordingly to prevent the cooling oil from spraying beyond the target area.

[0068] Alternatively, when the cooling oil pressure is high, a smaller first preset angle α1 can be selected, in which case the higher pressure can ensure that the cooling oil reaches the expected height; when the pressure is low, the first preset angle α1 needs to be increased to compensate for the range effect caused by insufficient pressure.

[0069] In practical applications, a correspondence between the first preset angle α1 and the winding end height and cooling medium pressure can be established based on the specific parameters of different motor models. This is used to adapt the optimal tilt angle for motors of different specifications. In this embodiment, the first preset angle α1 is configured as 45°.

[0070] It should also be noted that the specific dimensions of the first oil tank 410 and the second oil tank need to be designed according to the actual situation of the motor. As the main oil passage, the cross-sectional area of ​​the first oil tank 410 needs to meet the overall flow requirements; the dimensions of the second oil tank, especially the second set of sub-oil tanks 430, need to ensure appropriate injection speed and injection volume. These dimensions can be adjusted according to specific parameters such as the power rating of the motor, cooling requirements, and heat dissipation requirements.

[0071] In a preferred embodiment, the depth and width of the first oil tank 410 can be determined based on the dimensions of the stator core 400 and the total flow rate of the cooling oil to ensure sufficient cross-sectional area for cooling oil circulation. The dimensions of the first set of sub-oil tanks 420 and the second set of sub-oil tanks 430 can be set according to the required injection pressure and flow rate to ensure sufficient cooling effect while avoiding excessive pressure loss. Those skilled in the art can determine the optimal combination of oil tank dimensions through corresponding calculations to achieve structural compactness and material saving while ensuring cooling effect. In this embodiment, specific dimensions are not limited.

[0072] like Figure 9 — Figure 11 In a preferred embodiment, the oil cooling unit is provided with a central oil passage 520, a shaft end oil passage 510, and several radial oil passages in the rotor, and an end cover oil passage 310 is provided in the right end cover 300. The central oil passage 520 and the shaft end oil passage 510 are both located in the main shaft 500 of the rotor and are axially connected. The other end of the shaft end oil passage 510 is connected to the end cover oil passage 310. The radial oil passages are arranged circumferentially on the main shaft 500. The central oil passage 520 is connected to several radial oil passages. The cooling oil entering the central oil passage 520 can enter the radial oil passages through the rotation of the main shaft 500. The radial oil passages include a first radial oil passage, a second radial oil passage, and a third radial oil passage 570. The first radial oil passage is used to cool the bearing to reduce the operating temperature of the bearing and extend the service life of the bearing. The second radial oil passage is used to cool the inner surface of the winding to improve the heat dissipation efficiency of the winding. The third radial oil passage 570 is used to cool the rotor core 600. By setting up radial oil circuits with multiple branches, precise regional cooling of key motor components can be achieved, avoiding over-cooling in some areas while under-cooling in others. At the same time, each radial oil circuit is supplied with oil through a unified central oil circuit 520, simplifying the overall oil circuit structure and improving the reliability of the system.

[0073] Preferably, the number of the first radial oil passage, the second radial oil passage, and the third radial oil passage 570 can be the same or different. The number of each radial oil passage can be adaptively adjusted according to the heat generation characteristics and cooling requirements of different components to achieve a targeted cooling effect. The specific number is not limited here.

[0074] In a preferred embodiment, the first radial oil passage includes two sets of bearing cooling oil passages, namely a first bearing cooling oil passage 530 and a second bearing cooling oil passage 540 disposed at the left and right ends of the spindle 500. Both are evenly arranged along the circumference of the spindle 500 and are used to cool the bearings at both ends of the spindle 500, respectively.

[0075] like Figure 10 , Figure 11Preferably, in order to ensure that the cooling oil can be accurately sprayed to the target position of the bearing, a second preset angle α2 is provided between the first bearing cooling oil passage 530 and the central oil passage 520, and a third preset angle α3 is provided between the second bearing cooling oil passage 540 and the central oil passage 520. The second preset angle α2 and the third preset angle α3 are adapted to the specific installation position and cooling requirements of the bearing, so as to ensure that the bearings at both ends of the spindle 500 can be uniformly and fully cooled. By precisely controlling the preset angles, the cooling oil can be sprayed directly to the key parts of the bearing with the best trajectory, thereby improving the cooling efficiency.

[0076] Preferably, the second preset angle α2 and the third preset angle α3 can be adjusted independently according to actual working conditions. In this embodiment, the second preset angle α2 is configured as 40° and the third preset angle α3 is configured as 60°.

[0077] In a preferred embodiment, the second radial oil passage includes a first winding inner surface cooling oil passage 550 and a second winding inner surface cooling oil passage 560 located at both ends of the main shaft 500. Both are uniformly arranged along the circumference of the main shaft 500 and are respectively positioned at the two ends of the corresponding stator winding. By providing cooling oil passages at both ends of the main shaft 500, cooling oil can simultaneously spray and cool the inner surface of the stator winding from two directions, and can uniformly cover the entire inner surface of the stator winding, thereby avoiding local overheating and achieving a more uniform and comprehensive cooling effect.

[0078] like Figure 12 In a preferred embodiment, the rotor core 600 is provided with multiple rotor core cooling oil passages 610, each extending radially along the rotor core 600, and each rotor core cooling oil passage 610 corresponds one-to-one with a third radial oil passage 570 on the main shaft 500. This ensures that the cooling oil can be directly sprayed into the interior of the rotor core 600, achieving layer-by-layer cooling of the rotor core 600 from the inside out. Preferably, the rotor core cooling oil passages 610 are evenly distributed circumferentially along the rotor core 600 to achieve uniform cooling of the entire rotor core 600.

[0079] In this embodiment, the motor cooling system is configured as a dual cooling system combining water cooling and oil cooling, and its working process is as follows:

[0080] During the water cooling process in the water cooling unit, the cooling water first flows in through the inlet 110, then circulates along the motor housing 100 through the outer water channel 130 and the inner water channel 140, and then flows out through the outlet 120 after one cycle, so as to achieve comprehensive cooling of the motor housing 100.

[0081] During the oil circuit process in the oil cooling unit, the cooling oil flows into the heat exchange oil circuit 170 through the oil inlet 150, and then splits into two branches. The cooling oil of one branch enters the stator after passing through the first connecting passage and the first outer shell oil circuit cavity 171, while the cooling oil of the other branch enters the rotor after passing through the second connecting passage, the second outer shell oil circuit cavity 172 and the end cover oil circuit 310.

[0082] After entering the stator, the cooling oil passes through the first oil groove 410 and enters the second oil groove. Then, it is evenly sprayed along the second set of sub-oil grooves 430 onto the outer surface of the winding end. Finally, the cooling oil flows out through the oil outlet 160 after passing through the oil cavity 180.

[0083] After entering the rotor, the cooling oil passes through the shaft end oil passage 510 and enters the central oil passage 520. The cooling oil in the central oil passage 520 can enter each radial oil passage through the rotation of the main shaft 500. The cooling oil entering the first radial oil passage can be sprayed onto the bearing, the cooling oil entering the second radial oil passage can be sprayed onto the inner surface of the winding end, and the cooling oil entering the third radial oil passage 570 can be sprayed into the rotor core 600 through the rotor core cooling oil passage 610. All of the aforementioned cooling oil finally flows out through the oil outlet 160 after passing through the oil chamber 180.

[0084] In one embodiment of this utility model, a permanent magnet synchronous motor is also provided, including the motor cooling system described above. Specifically, other structures of the permanent magnet synchronous motor, such as the stator core 400, the arrangement of the stator windings, the structural design of the rotor core 600, the mounting method of the permanent magnet 700, and the selection of bearing types, can be flexibly adjusted and optimized according to actual application requirements, and this utility model embodiment does not impose specific limitations on them.

[0085] By adopting the motor cooling system of this invention, the cooling effect of permanent magnet synchronous motor can be effectively improved, the operating temperature of the motor can be reduced, and the power density and operational reliability of the motor can be increased.

[0086] This utility model embodiment also provides a vehicle, preferably a pure electric new energy vehicle, including the permanent magnet synchronous motor as described above. Other structures of the vehicle, such as the configuration of the power battery system, the design of the vehicle control system, the layout of the transmission system, as well as the body structure and chassis system, can be flexibly adjusted and optimized according to actual application requirements. This utility model embodiment does not make specific limitations in this regard.

[0087] Preferably, the vehicle can also be a purely electric commercial vehicle. By adopting the permanent magnet synchronous motor of this invention, the power density and operational reliability of the vehicle drive system can be improved, effectively enhancing overall vehicle performance and providing strong support for the development of new energy vehicles.

[0088] Although exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above exemplary embodiments are merely illustrative and are not intended to limit the scope of this application. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of this application. All such changes and modifications are intended to be included within the scope of this application as claimed in the appended claims.

[0089] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of this application may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0090] Similarly, it should be understood that, in order to streamline this application and aid in understanding one or more of the various aspects of the invention, features of this application may sometimes be grouped together in a single embodiment, figure, or description thereof in the description of exemplary embodiments of this application. However, this approach should not be construed as reflecting an intention that the claimed application requires more features than are expressly recited in each claim. Rather, as reflected in the corresponding claims, its novelty lies in the fact that the corresponding technical problem can be solved with fewer features than all of those in a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of this application.

[0091] Those skilled in the art will understand that, apart from the mutual exclusion of features, all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or elements of any method or apparatus so disclosed can be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature serving the same, equivalent, or similar purpose.

Claims

1. A motor cooling system, characterized in that, Includes the motor housing, stator, rotor, water-cooling unit, and oil-cooling unit; The water-cooling unit includes an outer water channel and an inner water channel disposed on the motor housing; The oil cooling unit includes a heat exchange oil circuit and a first oil tank, a second oil tank, a central oil circuit, and a radial oil circuit connected thereto. The heat exchange oil passage is located between the outer water passage and the inner water passage; The first oil groove is arranged circumferentially along the outer diameter of the stator core of the stator, and the second oil groove is arranged at the axial end of the first oil groove and communicates with it; Both the central oil passage and the radial oil passage are located inside the main shaft of the rotor and are connected to each other. The radial oil passage is open on the outer surface of the main shaft and is used to cool the bearings, the inner surface of the windings, and the rotor core.

2. The motor cooling system according to claim 1, characterized in that, The outer water channel and the inner water channel are both arranged in a U-shape on the motor housing and are interconnected. The motor housing is provided with a water inlet and a water outlet, and the water inlet and the water outlet are both connected to the outer water channel and the inner water channel.

3. The motor cooling system according to claim 2, characterized in that, The heat exchange oil circuit is arranged in a U-shape, and the motor housing is provided with an oil inlet and an oil outlet. The oil inlet is connected to the heat exchange oil circuit. The motor housing is provided with end caps at both ends. The oil cooling unit also includes an end cap oil passage provided on the end cap, an oil cavity provided inside the motor housing, and a first housing oil passage cavity and a second housing oil passage cavity provided on the inner wall of the motor housing. The heat exchange oil circuit is connected to the first outer shell oil circuit cavity through the first connecting passage, and the heat exchange oil circuit is connected to the second outer shell oil circuit cavity through the second connecting passage. The second outer shell oil circuit cavity extends axially and is connected to the end cover oil circuit. The oil chamber is connected to the oil outlet and is used to collect returned oil.

4. The motor cooling system according to claim 3, characterized in that, The second oil tank includes a first set of sub-oil tanks and a second set of sub-oil tanks, both of which are evenly arranged along the circumference of the stator core. The first set of sub-oil grooves extends axially, the second set of sub-oil grooves extends obliquely at a first preset angle, and the second set of sub-oil grooves penetrates the stator core, for spraying cooling medium onto the outer surface of the end of the stator winding.

5. The motor cooling system according to claim 3, characterized in that, The oil cooling unit also includes a shaft end oil passage, the two ends of which are connected to the end cover oil passage and the center oil passage, respectively.

6. The motor cooling system according to claim 4, characterized in that, The radial oil passage includes a first radial oil passage for cooling the bearing, a second radial oil passage for cooling the inner surface of the winding, and a third radial oil passage for cooling the rotor core. The central oil passage is arranged axially within the main shaft. The first radial oil passage includes a first bearing cooling oil passage and a second bearing cooling oil passage. Both the first bearing cooling oil passage and the second bearing cooling oil passage are evenly arranged circumferentially along the main shaft. A second preset angle is provided between the first bearing cooling oil passage and the central oil passage, and a third preset angle is provided between the second bearing cooling oil passage and the central oil passage.

7. The motor cooling system according to claim 6, characterized in that, The second radial oil passage is evenly arranged along the circumference of the main shaft. The second radial oil passage includes a first winding inner surface cooling oil passage and a second winding inner surface cooling oil passage located at both ends of the main shaft. The first winding inner surface cooling oil passage and the second winding inner surface cooling oil passage are respectively located at the positions corresponding to both ends of the stator winding.

8. The motor cooling system according to claim 6, characterized in that, The oil cooling unit also includes several rotor core cooling oil passages, which are arranged circumferentially along the rotor core. The rotor core cooling oil passages are connected to the third radial oil passage in a one-to-one correspondence. The rotor core cooling oil passages are used to spray the cooling medium into the rotor core.

9. A permanent magnet synchronous motor, characterized in that, Includes the motor cooling system as described in any one of claims 1-8.

10. A vehicle, characterized in that, Including the permanent magnet synchronous motor as described in claim 9.

Images