Motor assembly and vehicle

Abstract

The application provides a motor assembly and a vehicle, and belongs to the technical field of thermal management. The motor assembly comprises an outer shell, a stator assembly, a rotor assembly and a winding set. The outer shell has a containing cavity. The outer shell is provided with a first oil inlet and a second oil inlet. The radially inner edge of the stator assembly extends along the axial direction to abut against the two side cavity walls of the containing cavity respectively, so as to separate the containing cavity into an inner cavity and an outer cavity. The outer cavity is communicated with the first oil inlet. The rotor assembly is arranged in the stator assembly. The axial ends of the rotor assembly are rotationally connected with the outer shell. The rotor assembly is provided with a rotor oil passage. The oil inlet end of the rotor oil passage is communicated with the second oil inlet, and the oil outlet end is communicated with the inner cavity. The winding set is arranged in the stator assembly and is arranged in the outer cavity. The shell wall of the outer shell is provided with an oil outlet channel. The oil outlet channel is provided with a first oil outlet communicated with the outer cavity and a second oil outlet communicated with the inner cavity. The motor assembly and the vehicle provided by the application can improve the uniformity and cooling efficiency of the internal cooling of the motor.

Description

Technical Field

[0001] This application belongs to the field of thermal management technology, and more specifically, relates to an electric motor assembly and a vehicle. Background Technology

[0002] New energy vehicle drive motors and high-end equipment servo motors are continuously evolving towards higher power density and higher torque density. The heat loss per unit volume of the motor is also increasing dramatically. The uniformity and speed of cooling of the motor stator, rotor and windings directly affect the motor's continuous output capability.

[0003] In traditional technology, the cooling method of motors is mostly through connected oil circuits. For example, the stator oil circuit cools the stator and then flows to the winding end and enters the motor cavity. The rotor oil circuit cools the rotor and then flows into the motor cavity to mix with the stator oil circuit before exiting the outer casing. However, the mixed oil exists in the motor cavity, and the high temperature oil in the mixed oil can easily cause reverse heating of the stator components or windings in the mixing area, forming local hot spots. Summary of the Invention

[0004] The purpose of this application is to provide an electric motor assembly and vehicle that improves the cooling efficiency and uniformity of the electric motor and reduces the risk of localized overheating.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: In a first aspect, a motor assembly is provided, comprising: The outer casing has a receiving cavity; the outer casing is provided with a first oil inlet and a second oil inlet; A stator assembly is placed within the receiving cavity; the radial inner edge of the stator assembly extends axially to abut against the two side walls of the receiving cavity, thereby dividing the receiving cavity into an inner and outer independent inner cavity and an outer cavity; the outer cavity communicates with the first oil inlet. A rotor assembly is placed within the internal cavity and passes through the stator assembly; both axial ends of the rotor assembly are rotatably connected to the outer casing; the rotor assembly is provided with a rotor oil passage, the oil inlet of which communicates with the second oil inlet, and the oil outlet of which communicates with the internal cavity; and The winding assembly is wound inside the stator assembly and placed inside the outer cavity; The outer shell has an oil outlet channel inside its shell wall, and the oil outlet channel has a first oil outlet that connects to the outer cavity, a second oil outlet that connects to the inner cavity, and an oil return port that extends out of the outer shell.

[0006] Compared with the prior art, the solution shown in this application embodiment can divide the receiving cavity into an inner cavity and an outer cavity by extending the radial inner edge of the stator assembly along its circumference to abut against the inner wall of the receiving cavity. The stator assembly and the winding group are concentrated in the outer cavity, and the rotor assembly is concentrated in the inner cavity, thereby achieving spatial isolation between the stator assembly and the rotor assembly. Cooling oil can enter the outer cavity through the first oil inlet to immerse and cool the stator assembly and winding assembly, and then guide the cooled high-temperature oil to the oil outlet channel through the first oil outlet; cooling oil can also enter the rotor oil circuit of the rotor assembly through the second oil inlet to cool the rotor assembly, and guide the cooled high-temperature oil to the oil outlet channel through the inner cavity and the second oil outlet. Since the oil outlet channel is integrated inside the shell wall of the outer casing, the high-temperature oil after cooling the rotor assembly and stator assembly will not accumulate or remain in the cavity, thus avoiding the impact of the high-temperature oil on the bottom of the stator assembly or the winding assembly. Therefore, the embodiments of this application achieve relative independence between the inner cavity and the outer cavity, and achieve mutual independence between the cooling systems of the rotor assembly and the stator assembly. The high-temperature oil after cooling does not accumulate in the inner cavity, but is directly discharged after accumulating in the oil outlet channel in the outer shell wall. This avoids the mixing of high-temperature oil in different cooling systems, realizes independent cooling of the stator assembly and the rotor assembly, avoids the accumulation of cooling oil in the motor housing cavity, reduces the risk of reverse heating of the bottom stator core or winding assembly, can significantly improve the cooling efficiency and cooling uniformity of the motor, and reduce the risk of local overheating.

[0007] In conjunction with the first aspect, in one possible implementation, the first oil outlet is positioned above the top of the winding assembly in the vertical direction of the housing.

[0008] In this embodiment, since the height of the first oil outlet is higher than the top of the winding assembly, the cooling oil needs to reach the height of the first oil outlet before it can be discharged outward. Therefore, the accumulation height of the cooling oil in the outer cavity can be higher than that of the winding assembly, thereby achieving full immersion cooling of the winding assembly and effectively improving the cooling effect of the winding assembly.

[0009] In some embodiments, the first oil inlet is located at the top of the outer casing and extends downward into the outer cavity; The first oil outlet is located at the top of the outer cavity and extends along the axial direction of the rotor assembly; The first oil outlet and the first oil inlet are respectively located at the two ends of the axial direction of the stator assembly.

[0010] In this embodiment, the first oil inlet is located at the top of the outer casing so that the height of the first oil inlet is higher than the height of the cooling oil immersed in the outer cavity, thus preventing the cooling oil from overflowing from the first oil inlet. Furthermore, the first oil outlet and the first oil inlet are located at opposite ends of the axial direction of the stator assembly, allowing oil to enter from one side and exit from the other side, ensuring sufficient contact between the cooling oil and the stator assembly and the winding assembly, thereby improving the cooling effect.

[0011] In conjunction with the first aspect, in one possible implementation, the oil outlet channel includes: The first oil passage extends vertically within the side wall of the outer casing; the upper end of the first oil passage is provided with the first oil outlet. The second oil passage is located inside the bottom shell wall of the outer casing; one end of the second oil passage extends upward and is provided with the second oil outlet, and the extended end of the second oil passage is also connected to the lower end of the first oil passage; the bottom of the second oil passage is provided with the oil return port.

[0012] In this embodiment, a first oil passage is provided to guide the high-temperature cooling oil overflowing from the first oil outlet at the top to the second oil passage, and then the high-temperature oil in the outer cavity is discharged out of the outer shell through the oil return port on the second oil passage; the second oil passage is connected to the second oil outlet and is used to discharge the high-temperature cooling oil in the inner cavity through the second oil passage.

[0013] In some embodiments, the first oil passage includes: An upper oil passage extends vertically and is provided with a first oil outlet. An arc-shaped oil passage is arranged around the periphery of the rotor assembly and communicates with the lower end of the upper oil passage; and The lower oil passage has one end connected to the arc-shaped oil passage and the other end extending downwards to connect with the second oil passage.

[0014] The upper oil passage is used to connect to the first oil outlet, and the arc-shaped oil passage is used to make way for the rotor assembly in the center and extend the flow path of the first oil passage to promote side cooling of the motor housing; the lower oil passage is used to connect to the second oil passage to realize the flow of oil from top to bottom.

[0015] For example, the inner cavity is provided with a set of second oil outlets at both ends along the axial direction of the rotor assembly. The second oil passage is a U-shaped oil passage with the opening facing upward. The two ends of the U-shaped oil passage are connected to the two sets of second oil outlets respectively, and one end of the U-shaped oil passage is also connected to the lower end of the first oil passage.

[0016] In this embodiment of the application, by setting two sets of second oil outlets and U-shaped oil channels corresponding to the two sets of second oil outlets, the cooling oil can be discharged from the two sets of second oil outlets respectively, so as to realize the simultaneous discharge of high-temperature oil on both sides of the inner cavity and improve the flow rate of the cooling oil.

[0017] In conjunction with the first aspect, in one possible implementation, the stator component includes: A stator core is arranged around the rotor assembly; the stator core is provided with an axially extending mounting groove and an axially extending oil passage. Two end rings are clamped relative to each other at both axial ends of the stator core, and the radial inner edge of the end rings extends axially along the rotor assembly to abut against the cavity wall of the receiving cavity. The winding assembly is wound within the mounting groove, and both ends extend out of the mounting groove to form extension sections, which are wound around the extension ends of the end ring.

[0018] In this embodiment, a stator core oil circuit is provided on the stator core to achieve internal cooling of the stator core; by providing two end rings, the stator core can be clamped, and the radial extension of the inner edge of the end rings allows the radial inner edge of the end rings to abut against the cavity wall of the receiving cavity, thereby dividing the receiving cavity into an inner cavity and an outer cavity; in addition, the radially extended portion of the end rings can provide internal support for the winding assembly to support the extension section of the winding assembly.

[0019] In some embodiments, the inner wall of the receiving cavity is provided with a support ring corresponding to the end ring. The support ring extends axially into the end ring and is in close contact with the inner wall of the end ring to separate the outer cavity and the inner cavity. A sealing ring is provided between the outer wall of the support ring and the inner wall of the end ring. The extension section is wound around the support ring.

[0020] In this embodiment, a support ring is provided to facilitate contact between the inner wall of the cavity and the end ring. A sealing ring is provided to further improve the sealing at the connection between the end ring and the support ring, preventing the oil from flowing between the outer cavity and the inner cavity. At the same time, the support ring and the end ring can support the extension of the winding assembly in the inner layer.

[0021] In conjunction with the first aspect, in one possible implementation, the rotor assembly includes: A rotor shaft is rotatably connected to the housing; the rotor shaft is provided with a shaft oil passage extending along its axial direction, and the oil inlet end of the shaft oil passage is connected to the second oil inlet. A rotor core is sleeved and fixed on the rotor shaft; the rotor core is provided with a rotor core oil passage, the oil inlet of the rotor core oil passage is connected to the oil outlet of the rotor shaft oil passage, and the oil outlet is connected to the internal cavity; The rotor oil circuit includes the rotor shaft oil circuit and the rotor core oil circuit.

[0022] In this embodiment, by setting a shaft oil passage on the rotor shaft and a core oil passage on the rotor core, the cooling oil can sequentially pass through the rotor assembly from the second oil inlet, the shaft oil passage, and the core oil passage, thereby achieving cooling of the rotor core and the rotor shaft.

[0023] Secondly, embodiments of this application also provide a vehicle that includes the aforementioned motor assembly.

[0024] The vehicle provided in this application, having the aforementioned motor assembly, possesses all the beneficial effects of the aforementioned motor assembly. It enables independent cooling of the stator assembly and rotor assembly, avoids the accumulation of cooling oil in the motor housing cavity, reduces the risk of reverse heating of the bottom stator core or winding assembly, significantly improves the cooling efficiency and cooling uniformity of the motor, and reduces the risk of local overheating. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A cross-sectional structural schematic diagram of the motor assembly provided in the embodiments of this application; Figure 2 A schematic diagram of the internal oil flow path of the motor assembly provided in the embodiments of this application; Figure 3 This is a schematic cross-sectional view of the rotor assembly provided in an embodiment of this application; Figure 4 This is a cross-sectional structural diagram of the outer casing provided in an embodiment of this application; Figure 5 A cross-sectional structural diagram of the end cap provided in an embodiment of this application; Figure 6 A three-dimensional structural schematic diagram of the end cap provided in an embodiment of this application; Figure 7 for Figure 1 Enlarged structural diagram at point A Figure 1 ; Figure 8 for Figure 1 Enlarged structural diagram at point A Figure 2 ; Figure 9 for Figure 1 Enlarged structural diagram at point A Figure 3 .

[0027] In the diagram: 1. Outer shell; 11. First oil inlet; 12. Second oil inlet; 13. Outer cavity; 14. Inner cavity; 15. Support ring; 16. Oil outlet channel; 161. First oil passage; 1611. Upper oil passage; 1612. Arc-shaped oil passage; 1613. Lower oil passage; 1614. Guide rib; 1615. Connecting oil passage; 162. Second oil passage; 17. First oil outlet; 18. Second oil outlet; 19. Oil return port; 2. Stator assembly; 21. Stator core; 211. Stator core oil passage; 22. End ring; 3. Rotor assembly; 31. Rotor shaft; 311. Rotor shaft oil passage; 312. First radial oil passage; 313. Second radial oil passage; 32. Rotor core; 321. Rotor core oil passage; 4. Winding assembly; 41. Extension section; 5. Sealing ring. Detailed Implementation

[0028] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0029] It should be noted that when an element is referred to as being "set on" another element, it can be directly on or indirectly on that other element. It should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0030] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0031] It should be noted that the orientation or positional relationship indicated by "inner", "outer", "upper", "lower" etc. in this embodiment is based on the orientation of the motor itself. The top of the motor represents "upper", the bottom of the motor represents "lower", "inner" side refers to the side facing the rotor assembly inside the cavity, and "outer" side refers to the side facing the outside of the motor.

[0032] In addition, the vertical direction of the motor is defined as the vertical direction of the motor when it is installed or in use, which can also be understood as the vertical direction of the motor when it is installed or in use.

[0033] In traditional motor cooling oil circuit design, a continuous oil circuit layout is often adopted to simplify the flow channel structure and reduce the number of external pipes. Specifically, the stator cooling oil flows through the internal channels of the housing or stator core, passing over the core and part of the winding surface, and then flows into the internal cavity of the motor by gravity or the action of an oil slinger. The rotor cooling oil flows through the central hole of the shaft or the magnet slot, passing over the rotor core, magnets, and balance end plate, and then is thrown out under the action of centrifugal force, also flowing into the motor cavity. The two oils mix naturally in the internal cavity of the motor, and are finally discharged from the oil return port at the bottom of the housing and flow back to the external oil tank, completing the circulation.

[0034] However, a significant cumulative temperature rise effect exists in the aforementioned interconnected oil circuits. After absorbing heat from the stator core and windings, the stator oil temperature typically rises to 80-100°C or even higher; after carrying away heat from the magnets and shaft, the rotor oil temperature is also at a similar level. When the two high-temperature oils mix in the motor cavity, although the mixed oil temperature is relatively uniform, it is still higher than the initial temperature of the surfaces of each component before entering the cavity. This is especially true for the stator end windings, slot insulation, and core end faces near the mixing zone. Surfaces that have already been cooled by the initial low-temperature oil are reheated in the opposite direction when they come into contact with the high-temperature return oil after mixing. This causes the heat transfer direction in local areas to change from heat dissipation to heat absorption, significantly worsening the uniformity of the temperature field.

[0035] Furthermore, the mixed oil is not discharged from the cavity immediately. Its residence time is affected by factors such as the location of the return port, the oil flow rate, and the motor tilt angle, often forming localized stagnant eddies in the mixing zone for several seconds to tens of seconds. During this period, the high-temperature oil continuously surrounds or washes the winding ends, leads, and insulation supports, causing the heat in these areas to be unable to dissipate effectively and even accumulate continuously, forming localized hot spots that are higher than the design expectation.

[0036] Please refer to the following: Figures 1 to 9The motor assembly and vehicle provided in this application will now be described. The motor assembly includes a housing 1, a stator assembly 2, a rotor assembly 3, and a winding assembly 4. The housing 1 has a receiving cavity. The housing 1 is provided with a first oil inlet 11 and a second oil inlet 12. The stator assembly 2 is placed in the receiving cavity. The radial inner edge of the stator assembly 2 extends axially to abut against the two side walls of the receiving cavity, thereby dividing the receiving cavity into an inner cavity 14 and an outer cavity 13, which are independent of each other. The outer cavity 13 communicates with the first oil inlet 11. The rotor assembly 3 is placed in the inner cavity 14 and passes through the stator assembly 2. Inside; the axial ends of the rotor assembly 3 are rotatably connected to the outer shell 1; the rotor assembly 3 is provided with a rotor oil passage, the oil inlet end of the rotor oil passage is connected to the second oil inlet 12, and the oil outlet end is connected to the inner cavity 14; the winding group 4 is wound inside the stator assembly 2 and placed inside the outer cavity 13; wherein, the shell wall of the outer shell 1 is provided with an oil outlet channel 16, the oil outlet channel 16 is provided with a first oil outlet 17 connected to the outer cavity 13, a second oil outlet 18 connected to the inner cavity 14, and an oil return port 19 extending to the outside of the outer shell 1.

[0037] Understandably, the radial inner edge of the stator assembly 2 extends axially and abuts against the cavity wall of the receiving cavity. Specifically, the radial inner edge of the stator assembly 2 extends axially along the rotor assembly 3, and when the extended stator assembly 2 abuts against the cavity wall of the receiving cavity, a seal is formed to prevent oil leakage from the abutment point, thereby achieving effective separation between the inner cavity 14 and the outer cavity 13.

[0038] The outer cavity 13 is used to house the stator assembly 2 and the winding assembly 4. After the cooling oil enters the outer cavity 13 from the first oil inlet 11, it realizes the immersion cooling of the stator assembly 2 and the winding assembly 4 to reduce the temperature of the stator assembly 2 and the winding assembly 4 and remove the heat generated by copper loss and iron loss. After absorbing heat, the oil flows into the oil outlet channel 16 through the first oil outlet 17 on the inner side of the shell wall.

[0039] The inner cavity 14 is used to accommodate the rotor assembly 3. Cooling oil enters the rotor oil circuit from the second oil inlet 12 to cool the rotor assembly 3. The cooled high-temperature oil enters the inner cavity 14 and is discharged from the second oil outlet 18 of the inner cavity 14 and flows into the oil outlet channel 16.

[0040] Therefore, the outer cavity 13 is specifically designed to address the winding copper losses that are difficult to dissipate heat and have a large heat load; the inner cavity 14 is specifically designed to address the rotor eddy current losses, avoiding the additional losses caused by the stirring of oil in the rotor assembly 3 during traditional immersion cooling; in addition, since the first oil inlet 11 and the second oil inlet 12 are independent of each other, the flow rate to the stator assembly 2 and the flow rate to the rotor assembly 3 can be adjusted separately by the external valve group to optimize the heat dissipation efficiency under different operating conditions.

[0041] It is worth noting that the oil outlet channel 16 is integrated into the shell wall of the outer shell 1. The oil outlet channel 16 is machined in the solid wall thickness of the outer shell, and the oil from the inner and outer cavities is collected and discharged in a unified manner. The oil converging point is located inside the shell wall of the outer shell 1, not in the receiving cavity of the outer shell 1. This avoids the influence of oil temperature rise changes at the converging point on the internal stator assembly 2 or rotor assembly 3, and avoids interference of heat radiation and heat conduction of the internal stator assembly 2 or rotor assembly 3 caused by oil temperature rise changes at the converging point. This ensures that the independent cooling temperature zones of the inner cavity 14 and the outer cavity 13 do not interfere with each other.

[0042] Understandably, although the solid metal of the outer casing 1 is thermally conductive, its outer side is usually in contact with the external air or water jacket. When the oil, after absorbing heat, mixes and releases heat inside the casing, the heat is preferentially conducted along the metal wall to the external environment (casing surface) rather than radiated to the inner cavity. This is equivalent to establishing a thermal barrier between the cavity and the hot oil junction point, which isolates the hot oil junction point from the rotor assembly 3 and stator assembly 2 inside the cavity.

[0043] Please see Figures 4 to 6 For example, the outer casing 1 includes an end cap and a casing body. One side of the casing body is open, and the end cap is placed on the open side of the casing body and encloses the aforementioned receiving cavity. The end cap and the casing body are detachably connected. The two axial ends of the rotor assembly 3 are rotatably connected to the end cap and the casing body respectively.

[0044] Specifically, the radial inner edge of the stator assembly 2 extends axially, with one end abutting and sealing against the inner wall of the end cover and the other end abutting and sealing against the inner wall of the housing body, so as to divide the receiving cavity into an inner cavity 14 and an outer cavity 13.

[0045] It is understood that the outer cavity 13 is a ring-shaped structure and is arranged around the outside of the inner cavity 14; the stator assembly 2 and the winding assembly 4 are also ring-shaped structures and are arranged around the outside of the rotor assembly 3.

[0046] Specifically, the oil outlet channel 16 has a first oil outlet 17 extending to the outer cavity 13 on the inner side facing the receiving cavity, and a second oil outlet 18 extending to the inner cavity 14; the oil outlet channel 16 has a return oil outlet 19 extending to the outer shell 1 on the outer side away from the receiving cavity. Optionally, the return oil outlet 19 is located at the bottom of the outer shell 1 so as to use the weight of the oil itself to discharge the heated oil from the bottom.

[0047] Compared with the prior art, the motor assembly provided in this application can divide the receiving cavity into an inner cavity 14 and an outer cavity 13 by extending the radial inner edge of the stator assembly 2 along its circumference to abut against the inner wall of the receiving cavity. The stator assembly 2 and the winding group 4 are concentrated in the outer cavity 13, and the rotor assembly 3 is concentrated in the inner cavity 14, thereby achieving spatial isolation between the stator assembly 2 and the rotor assembly 3.

[0048] Cooling oil can enter the outer cavity 13 through the first oil inlet 11 to immerse and cool the stator assembly 2 and the winding assembly 4. Then, the cooled high-temperature oil is guided to the oil outlet channel 16 through the first oil outlet 17. Cooling oil can also enter the rotor oil circuit of the rotor assembly 3 through the second oil inlet 12 to cool the rotor assembly 3. The cooled high-temperature oil is then guided to the oil outlet channel 16 through the inner cavity 14 and the second oil outlet 18.

[0049] Since the oil outlet channel 16 is integrated into the shell wall of the outer casing 1, the high-temperature oil after cooling the rotor assembly 3 and the stator assembly 2 will not accumulate or remain in the cavity, thus avoiding the impact of the high-temperature oil on the bottom of the stator assembly 2 or the winding group 4.

[0050] Therefore, this embodiment achieves relative independence between the inner cavity 14 and the outer cavity 13, and makes the cooling systems of the rotor assembly 3 and the stator assembly 2 independent of each other. The cooled high-temperature oil does not accumulate in the inner cavity, but is directly discharged after accumulating in the oil outlet channel 16 in the outer shell 1, avoiding the mixing of high-temperature oil in different cooling systems. This achieves independent cooling of the stator assembly 2 and the rotor assembly 3, avoids the accumulation of cooling oil in the motor cavity, reduces the risk of reverse heating of the bottom stator core 21 or the winding group 4, and can significantly improve the cooling efficiency and cooling uniformity of the motor, reducing the risk of local overheating.

[0051] Please see Figure 1 and Figure 4 In some possible embodiments, the first oil outlet 17 is positioned above the top of the winding assembly 4 in the vertical direction of the housing 1.

[0052] In this embodiment, since the height of the first oil outlet 17 is higher than the top of the winding assembly 4, the cooling oil needs to reach the height of the first oil outlet 17 before it can be discharged outward. Therefore, the accumulation height of the cooling oil in the outer cavity 13 can be higher than that of the winding assembly 4, thereby achieving full immersion cooling of the winding assembly 4 and effectively improving the cooling effect of the winding assembly 4.

[0053] By setting the height of the first oil outlet 17, the oil can accumulate in the outer cavity 13. Since the first oil outlet 17 is higher than the top of the winding, after the cooling oil is injected into the outer cavity 13 from the first oil inlet 11, it can completely submerge the entire winding assembly 4. Only then will the oil level rise to the top of the first oil inlet 11 and overflow.

[0054] When the copper wires at the ends of the winding assembly 4 and in the groove are submerged, their surface area can be kept in contact with the cooling oil. Compared with spray cooling, full immersion cooling can eliminate the risk of local overheating at the top of the winding assembly 4 and improve heat exchange efficiency.

[0055] It is understandable that the winding assembly 4 is wound on the rotor assembly 3. In the vertical direction of the outer casing 1, when the first oil outlet 17 is higher than the top of the winding assembly 4, the cooling oil in the outer cavity 13 will immerse the winding assembly 4 and the rotor assembly 3 that passes through the stator assembly 2. Therefore, the cooling oil in the outer cavity 13 can form a cooling layer outside the inner cavity 14 to further reduce the temperature inside the inner cavity 14.

[0056] In addition, an oil outlet channel 16 is provided inside the shell wall of the outer shell 1. The oil discharged in the oil outlet channel 16 carries a certain amount of heat. The oil outlet channel 16 is separated from the outer cavity 13 by a portion of the shell wall. The oil outlet channel 16 is separated from the inner cavity 14 by a portion of the shell wall and the oil immersion layer of the outer cavity 13. Therefore, the influence of the oil discharged outward on the rotor assembly 3 of the inner cavity 14 can be effectively avoided.

[0057] Please see Figure 1 and Figure 4 In some embodiments, the first oil inlet 11 is located at the top of the outer casing 1 and extends downward into the outer cavity 13; the first oil outlet 17 is located at the top of the outer cavity 13 and extends along the axial direction of the rotor assembly 3; wherein the first oil outlet 17 and the first oil inlet 11 are respectively located at the two ends of the axial direction of the stator assembly 2.

[0058] In this embodiment, the first oil inlet 11 is located at the top of the outer casing 1, so that the height of the first oil inlet 11 is higher than the height of the cooling oil immersed in the outer cavity 13, thus preventing the cooling oil from overflowing from the first oil inlet 11. Furthermore, the first oil outlet 17 and the first oil inlet 11 are respectively located at the two ends of the axial direction of the stator assembly 2, which can realize oil inlet on one side and oil outlet on the other side, ensuring that the cooling oil has sufficient contact with the stator assembly 2 and the winding group 4, thereby improving the cooling effect.

[0059] Cooling oil enters the outer cavity 13 from the top first oil inlet 11. Relying on gravity and jet kinetic energy, the oil can flow downward and impact the winding end of one axial end of the stator assembly 2. The first oil outlet 17 is located at the top of the other axial end of the stator assembly 2 and is in the shape of an axially extending elongated hole. When the cooling oil is discharged, it needs to flow from one end of the winding group 4 near the first oil inlet 11 to the other end so that it can overflow from the laterally extended first oil outlet 17.

[0060] It is understandable that the oil in the rotor oil passage within the inner cavity 14 flows primarily through centrifugal force, tending to flow radially; while the oil in the outer cavity 13 flows axially. The two cooling media flow directions are orthogonal, shearing each other at the stator-rotor air gap, which is beneficial for cooling the partition structure that isolates the inner cavity 14 and the outer cavity 13 from different directions, thus improving the cooling effect of the partition structure; specifically, the partition structure includes a structure in which the stator assembly 2 extends axially to abut against the inner wall of the receiving cavity.

[0061] In addition, since the first oil inlet 11 and the first oil outlet 17 are respectively located on both sides of the stator assembly 2, and both the first oil inlet 11 and the first oil outlet 17 are located above the winding group 4, the top of the outer cavity 13 is the most active flow area. The trace amount of air or oil vapor that is released at high temperature will be directly carried into the first oil outlet 17 and discharged with the high-speed oil flow at the top, thus avoiding the accumulation of hot air flow inside the cavity.

[0062] Specifically, the first oil outlet 17 is located at the top of the outer cavity 13, the second oil outlet 18 is located at the bottom of the inner cavity 14, and the oil return port 19 is located at the bottom of the outer shell 1; the oil outlet channel 16 extends downward from the top of the outer shell 1 to the bottom, so as to communicate with the first oil outlet 17, the second oil outlet 18 and the oil return port 19 respectively.

[0063] As can be seen, the first oil outlet 17, the second oil outlet 18 and the return oil outlet 19 are distributed from top to bottom, and the oil outlet channel 16 extends from top to bottom to the bottom, which can receive the cooled oil from the outer cavity 13 and the inner cavity 14 in sequence, and exit the outer shell 1 through the return oil outlet 19 at the bottom.

[0064] It should be noted that the first oil outlet 17, the second oil outlet 18, the first oil inlet 11, and the second oil inlet 12 can all be configured as oil hole structures or as oil passage structures with a certain extension length to realize the introduction or export of oil. Furthermore, an oil cavity can be provided at the first oil outlet 17, which is connected to the first oil outlet 17, and the height of the oil cavity is higher than the height of the first oil outlet 17, so as to accommodate the hot air or high-temperature oil vapor at the top and avoid the accumulation of hot airflow that blocks the first oil outlet 17 and affects the overflow of oil.

[0065] For example, the second oil outlet 18 is an oil passage structure formed by an inclined hole extending at an incline. The second oil outlet 18 extends downward at an incline from the bottom of the inner cavity 14, and the extended end of the second oil outlet 18 communicates with the second oil passage 162. In addition, the extended end of the second oil outlet 18 extends through the second oil passage 162.

[0066] Overall, the cooling system of this motor assembly consists of two independent oil inlets, independent cooling channels, and a final convergence of oil lines. The first oil inlet 11 is located at the top of the outer casing 1 and is responsible for supplying cooling oil to the outer cavity 13 (stator side); the second oil inlet 12 is located at the end of the outer casing 1 and is responsible for supplying cooling oil to the inner cavity 14 (rotor side). After each oil line has completed cooling of its target components, the two oil lines flow out through the first oil outlet 17 located at the top of the casing and the second oil outlet 18 located at both axial ends at the bottom of the casing, respectively, and converge into the oil outlet channel 16 embedded in the casing wall of the outer casing 1, and are discharged to the external cooler through the return oil outlet 19.

[0067] Please see Figure 4 In some possible embodiments, the oil outlet channel 16 includes a first oil channel 161 and a second oil channel 162; the first oil channel 161 extends vertically and is disposed within the side shell wall of the outer casing 1; the upper end of the first oil channel 161 is provided with a first oil outlet 17; the second oil channel 162 is disposed within the bottom shell wall of the outer casing 1; one end of the second oil channel 162 extends upward and is provided with a second oil outlet 18, and the extended end of the second oil channel 162 is also connected to the lower end of the first oil channel 161; the bottom of the second oil channel 162 is provided with an oil return port 19.

[0068] In this embodiment, a first oil passage 161 is provided to guide the high-temperature cooling oil overflowing from the first oil outlet 17 at the top to the second oil passage 162, and then the high-temperature oil in the outer cavity 13 is discharged out of the outer shell 1 through the oil return port 19 on the second oil passage 162; the second oil passage 162 is connected to the second oil outlet 18 and is used to discharge the high-temperature cooling oil in the inner cavity 14 through the second oil passage 162.

[0069] Specifically, the hot oil path of the outer cavity 13 is as follows: it enters the first oil passage 161 from the first oil outlet 17 at the top, and falls vertically and rapidly to the bottom of the shell wall under its own gravity and the negative pressure traction of the return oil pump.

[0070] Hot oil path in inner cavity 14: It enters the extension end of the second oil passage 162 from the bottom second oil outlet 18 and mixes with the oil at the lower end of the first oil passage 161. The mixed oil is finally discharged from the return oil outlet 19 at the bottom of the second oil passage 162.

[0071] One end of the second oil passage 162 extends upward to allow the bottom second oil passage 162 to bypass the lower half of the outer cavity 13, thereby forming a second oil outlet 18 that communicates with the inner cavity 14 to meet the requirements of the oil discharge height of the inner cavity 14.

[0072] Optionally, an arc transition guide surface is provided at the intersection of the first oil passage 161 and the second oil passage 162 to facilitate smooth oil convergence and reduce impact energy.

[0073] Please see Figure 5In some embodiments, the first oil passage 161 includes an upper oil passage 1611, an arc-shaped oil passage 1612, and a lower oil passage 1613; the upper oil passage 1611 extends vertically and has a first oil outlet 17; the arc-shaped oil passage 1612 is arranged around the periphery of the rotor assembly 3 and is connected to the lower end of the upper oil passage 1611; one end of the lower oil passage 1613 is connected to the arc-shaped oil passage 1612, and the other end extends downward to connect with the second oil passage 162.

[0074] The upper oil passage 1611 is used to connect to the first oil outlet 17, and the arc-shaped oil passage 1612 is used to make way for the rotor assembly 3 at the center and extend the flow path of the first oil passage 161 to promote side cooling of the motor housing; the lower oil passage 1613 is used to connect to the second oil passage 162 to realize the flow of oil from top to bottom.

[0075] Specifically, the upper oil passage 1611 is located on the top of the side wall of the housing to quickly receive the hot oil overflowing from the top of the outer cavity, and accelerates its fall by gravity to establish initial flow potential energy; the arc-shaped oil passage 1612 is located on the side wall of the housing and is arranged around the outside of the rotor assembly 3, which can realize forced pre-cooling, extend the heat exchange stroke, preferentially transfer heat to the outer casing, and avoid the rotor shaft 31 of the rotor assembly 3.

[0076] The lower oil passage 1613 is located at the bottom of the side wall of the housing, which can draw oil into the second oil passage 162 so that the oil can be discharged to the outside of the housing 1 by means of the second oil passage 162 at the bottom and the oil return port 19.

[0077] Specifically, after the oil in the outer cavity 13 absorbs heat, the high-temperature oil rises to the top and overflows from the first oil outlet 17, entering the upper oil passage 1611. Under the influence of gravity, the hot oil falls naturally along the vertical upper oil passage 1611 and then enters the arc-shaped oil passage 1612. The hot oil flows along the circumferential arc-shaped oil passage 1612 around the rotor assembly 3, and finally enters the lower oil passage 1613 and flows into the second oil passage 162 at the bottom, where it mixes with the hot oil discharged from the bottom of the inner cavity 14 in the second oil passage 162 and is discharged through the return oil port 19.

[0078] Understandably, the oil travels around a semi-circular arc within the arc-shaped oil passage 1612, extending its residence time; heat is conducted through the shell wall metal to the external heat dissipation fins / water jacket, achieving initial cooling and preventing high-temperature oil from directly impacting the confluence area of ​​the second oil passage 162.

[0079] For example, the arc-shaped oil passage 1612 is semi-circular, and the semi-circular arc-shaped oil passage 1612 is coaxially arranged with the rotor assembly 3; optionally, a transition arc surface is provided at the junction of the arc-shaped oil passage 1612 and the upper oil passage 1611 or the lower oil passage 1613 to alleviate the impact at the oil diversion point.

[0080] Specifically, the first oil passage 161 is located inside the shell wall of the end cover. The upper end of the upper oil passage 1611 extends to a height higher than the first oil outlet 17. The cross-sectional dimension of the first oil outlet 17 is larger than the cross-sectional dimension of the upper oil passage 1611. The cross-sectional dimension of the arc-shaped oil passage 1612 is larger than the cross-sectional dimension of the upper oil passage 1611.

[0081] Optionally, the end cap is also provided with a guide rib 1614, which is arranged in an arc shape around the rotor assembly 3 to surround the arc-shaped oil passage 1612 and guide the oil from the upper oil passage 1611 to the lower oil passage 1613. Furthermore, the height of the guide rib 1614 is consistent with the weak current sealing surface. When the oil flows downward through the overflow port by gravity, the oil can be guided to the lower oil passage 1613 along the path of the guide rib 1614. The structure of the guide rib 1614 can effectively avoid the oil churning loss and oil circuit non-circulation problems caused by the oil accumulating in the weak current resolver cavity after overflow. At the same time, the arc-shaped oil passage 1612 and the guide rib 1614 can prevent the oil overflowing from the outer cavity 13 from re-entering the outer cavity 13.

[0082] Please see Figure 5 It is understood that the two ends of the rotor assembly 3 are rotatably connected to the outer casing 1 through rotating bearings. Furthermore, the end cover is provided with a rotor end cavity 1616 that is annularly arranged on the rotor shaft 31. When the cooling oil in the inner cavity 14 is cooling the rotating bearing, some of the oil will enter the rotor end cavity 1616 from the gap of the rotating bearing through the weak electro-resolver cavity. The rotor end cavity 1616 is axially connected to the gap of the rotating bearing through the weak electro-resolver cavity.

[0083] For example, the bottom of the guide rib 1614 is provided with a connecting oil passage 1615, which is used to connect the arc-shaped oil passage 1612 and the rotor end cavity 1616, so that the oil in the rotor end cavity 1616 is guided to the second oil passage 162 through the arc-shaped oil passage 1612 and discharged to the outside of the outer casing 1 through the return oil port 19.

[0084] Please see Figure 4 For example, the inner cavity 14 is provided with a set of second oil outlets 18 at both ends along the axial direction of the rotor assembly 3. The second oil passage 162 is a U-shaped oil passage with an upward opening. The two ends of the U-shaped oil passage are connected to the two sets of second oil outlets 18 respectively, and one end of the U-shaped oil passage is also connected to the lower end of the first oil passage 161.

[0085] In this embodiment of the application, by setting two sets of second oil outlets 18 and U-shaped oil channels corresponding to the two sets of second oil outlets 18, the cooling oil can be discharged from the two sets of second oil outlets 18 respectively, so as to realize the simultaneous discharge of high-temperature oil on both sides of the inner cavity 14 and improve the flow rate of the cooling oil.

[0086] Specifically, the second oil outlet 18 is located at the bottom of the inner cavity 14, and there are two sets of the second oil outlet 18. The two sets of second oil outlets 18 are arranged at intervals along the circumference of the inner cavity 14, which can simultaneously realize the drainage of oil from both sides of the inner cavity 14 and prevent oil from accumulating in the inner cavity 14.

[0087] In this embodiment, a second oil outlet 18 is provided at each end to achieve symmetrical oil discharge from both ends in the axial direction, eliminating the axial pressure difference of the oil caused by oil discharge from one side. When the rotor rotates, the lubrication state of the bearings at both ends remains consistent, and the bearing life is balanced. The second oil passage 162 is U-shaped. When the vehicle pitches / tilts (such as climbing a hill or braking suddenly), the oil in the U-shaped second oil passage 162 will flow by gravity to compensate, ensuring that the lower end will not be evacuated and the higher end will not overflow into the air gap.

[0088] It should be noted that the oil return port 19 is located at the bottom of the U-shaped second oil passage 162 and extends downward to the outer side of the outer casing 1 so as to facilitate the outward discharge of oil.

[0089] Optionally, multiple sets of second oil outlets 18 are provided, and multiple sets of second oil outlets 18 are arranged at intervals along the circumference of the inner cavity 14. Each set of second oil outlets is connected to the second oil passage 162. Specifically, the second oil outlets 18 can be connected to the second oil passage 162 through connecting branches. At this time, the second oil passage 162 can be reasonably arranged according to the connection needs of multiple sets of second oil outlets 18.

[0090] Please see Figure 1 In some possible embodiments, the stator assembly 2 includes a stator core 21 and two end rings 22; the stator core 21 is circumferentially disposed on the rotor assembly 3; the stator core 21 is provided with an axially extending mounting groove and an axially extending stator core oil passage 211; the two end rings 22 are clamped relative to each other at both axial ends of the stator core 21, and the radial inner edge of the end rings 22 extends axially along the rotor assembly 3 to abut against the cavity wall of the receiving cavity; wherein, the winding group 4 is wound in the mounting groove, and both ends extend out of the mounting groove to form an extension section 41, and the extension section 41 is wound around the extension end of the end ring 22.

[0091] In this embodiment, a stator core oil passage 211 is provided on the stator core 21 to achieve internal cooling of the stator core 21; by providing two end rings 22, the stator core 21 can be clamped, and the inner edge of the end ring 22 extends radially so that the radial inner edge of the end ring 22 abuts against the cavity wall of the receiving cavity, thereby dividing the receiving cavity into an inner cavity 14 and an outer cavity 13 by the end ring 22; in addition, the radial inner edge extension of the end ring 22 can provide internal support for the winding assembly 4 to support the extension section 41 of the winding assembly 4.

[0092] The two end rings 22 can be made of aluminum, copper, or non-magnetic materials. The end rings 22 clamp the stator core 21 from both ends in the axial direction, and their radial inner edges extend axially to form an interference fit with the cavity wall of the housing, thus creating a physical barrier. It can be understood that the inner edge of the stator core 21 is located on the outer periphery of the rotor assembly 3, and the end rings 22 are clamped at both ends of the stator core 21. Therefore, the oil in the inner cavity 14 cannot enter the outer cavity 13 through the clamping gap between the end rings 22 and the stator core 21. Even if it occasionally enters through the gap, it is only a very small amount. Therefore, the radial inner edge of the stator core 21 and the end rings 22 together form a physical barrier structure between the inner cavity 14 and the outer cavity 13.

[0093] After the copper wire of the winding group 4 extends out from the mounting groove, it is directly wound on the axial extension end of the end ring 22. The end ring 22 serves as both the skeleton support of the winding and a thermal bridge for transferring heat to the outer casing 1.

[0094] Specifically, the stator core 21 is fixed within the receiving cavity of the outer casing 1, and remains stationary while the rotor assembly 3 rotates. The end ring 22 is subsequently fixed to the stator core 21 and remains stationary with it. The stator core 21 includes a plurality of first core laminations stacked sequentially along the axial direction of the rotor assembly 3. Each first core lamination has a first oil passage hole suitable for oil to pass through. The plurality of first oil passage holes on the plurality of first core laminations are sequentially connected along the axial direction of the rotor assembly 3, forming an axially extending stator core oil passage 211, so that oil can pass through the stator core oil passage 211 from one end of the stator core 21 to the other end of the stator core 21.

[0095] Please see Figure 7 or Figure 8 For example, the end ring 22 is a single piece, which can be divided into a sealing ring that is radially clamped between the rotor assembly 3 and the winding group 4, and an annular end plate that is axially clamped between the stator core 21 and the winding group 4. The annular end plate is connected to the end face of the stator core 21, and the sealing ring is sealed to the cavity wall of the receiving cavity. The annular end plate is provided with a relief groove at the same position as the mounting groove, and the size of the relief groove is larger than that of the mounting groove.

[0096] It should be noted that the annular end plate of the end ring 22 is provided with a second oil passage hole that is axially opposite to the first oil passage hole, so that the oil can be discharged or introduced from the second oil passage hole on the end ring 22; specifically, the stator oil passage of the stator assembly 2 includes the first oil passage hole and the second oil passage hole.

[0097] During cooling, the cooling oil is injected into the outer cavity 13 from the first oil inlet 11 at the top, directly flushing the extension section 41 wound around the end ring 22, carrying away the heat loss of copper. The stator core oil passage 211 specially set on the stator core 21 allows the cooling oil to flow from one end of the stator core 21 to the other end, directly carrying away the hysteresis loss and eddy current loss heat of the silicon steel sheet, and further cooling the winding group 4 at the other end, and then overflowing out of the outer cavity 13 from the first oil outlet 17 at the other end.

[0098] For example, as a second embodiment of the end ring 22, the end ring 22 includes a second sealing ring that is radially clamped between the rotor assembly 3 and the winding group 4, and a second annular end plate that is axially clamped between the stator core 21 and the winding group 4. Further, the second annular end plate is provided with a plurality of radially extending wedge grooves, one side of which penetrates the radial outer edge of the second annular end plate. One end of the second sealing ring abuts against the end face of the stator core 21, and the other end is sealed to the cavity wall of the receiving cavity.

[0099] Please see Figure 9 For example, as a third embodiment of the end ring 22, the end ring 22 is a single piece and only includes a third sealing ring that is radially sandwiched between the rotor assembly 3 and the winding group 4. One end of the third sealing ring abuts against the end face of the stator core 21, and the other end is sealed to the cavity wall of the receiving cavity. It can be understood that in this embodiment, the end ring 22 does not include the sealing ring portion that is axially sandwiched between the rotor assembly 3 and the winding group 4.

[0100] Specifically, the annular end plate of the end ring 22, which is axially clamped between the stator core 21 and the winding assembly 4, can be selectively set as needed. Optionally, the radial height of the annular end plate can be adjusted according to actual needs.

[0101] The end ring 22 can be injection molded and fixedly connected to the stator core 21 by welding, riveting or gluing. Optionally, the end ring 22 can be made of insulating material.

[0102] Please see Figure 1 and Figure 4 In some embodiments, the inner wall of the receiving cavity is provided with a support ring 15 corresponding to the end ring 22. The support ring 15 extends axially into the end ring 22 and is close to the inner wall of the end ring 22 to separate the outer cavity 13 and the inner cavity 14. A sealing ring 5 is provided between the outer wall of the support ring 15 and the inner wall of the end ring 22. The extension section 41 is wound around the support ring 15.

[0103] In this embodiment, a support ring 15 is provided to facilitate contact between the inner wall of the cavity and the end ring 22. A sealing ring 5 is provided to further improve the sealing performance at the connection between the end ring 22 and the support ring 15, preventing the oil from flowing between the outer cavity 13 and the inner cavity 14. At the same time, the support ring 15 and the end ring 22 can support the extension section 41 of the winding assembly 4 in the inner layer.

[0104] The support ring 15 is fixed to the inner wall of the housing cavity and extends axially. The outer wall has a groove for installing the sealing ring 5. The end ring 22 is fixed to the axial end of the stator core 21. The inner hole is fitted around the outside of the support ring 15 and clamped and fixed to the end of the stator core 21. The radial gap between the outer wall of the support ring 15 and the inner wall of the end ring 22 can be sealed by compression of the sealing ring 5.

[0105] In addition, after the copper wire extension 41 of the winding assembly 4 comes out of the mounting groove, it is directly wound on the outer circumference of the end ring 22 and the support ring 15. The end ring 22 and the support ring 15 provide support for the winding assembly 4 and form a physical isolation structure between the inner cavity 14 and the outer cavity 13.

[0106] Optionally, the support ring 15 is fixed to the inner cavity wall; specifically, the support ring 15 is integrally connected to the corresponding inner cavity wall of the outer shell 1, or the support ring 15 is fixed to the corresponding inner cavity wall by welding, bolting or other means.

[0107] Since the outer casing 1 is actually divided into an end cover and a motor housing, the two support rings 15 are actually one-to-one with the end cover and the motor housing. That is, one support ring 15 is fixed on the end cover and another support ring 15 is fixed inside the motor housing. The two are arranged opposite each other in the axial direction of the rotor assembly 3.

[0108] In this embodiment, the end ring 22 and the support ring 15 are sealed radially. Specifically, the support ring 15, the sealing ring 5 and the end ring 22 are stacked radially from the inside to the outside. Compared with the axial sealing method, that is, the support ring 15, the sealing ring 5 and the end ring 22 are stacked sequentially in the axial direction, the advantage of the radial sealing method is that the length of the iron core pole shoe can be controlled to be smaller and the electromagnetic performance is less affected.

[0109] Specifically, the iron core pole shoe is a key component in the magnetic circuit of equipment such as motors and electromagnets. It is an enlarged part of the main magnetic pole iron core near the rotor (or air gap). Through its special shape, the magnetic field generated by the magnetic pole is distributed more evenly in the air gap, thus optimizing the motor performance.

[0110] If an axial seal is used, the support ring 15, sealing ring 5, and end ring 22 must be arranged sequentially along the axial direction. This means that in order to allow for compression space and assembly clearance space for the sealing ring 5, the end ring 22 must be extended further along the axial direction, resulting in an increase in the total axial length of the entire stator assembly 2. However, the total length of the outer casing 1 is usually limited by the overall vehicle installation dimensions. In order to fit this seal, the effective stacking thickness of the iron core pole shoes can only be compressed, sacrificing electromagnetic performance.

[0111] In this design, the support ring 15, sealing ring 5, and end ring 22 are stacked radially from the inside out. The sealing ring 5 occupies only the radial thickness, with almost zero axial occupancy. The end ring 22 does not need to protrude axially outward for sealing, and the effective length of the iron core pole shoe can fully utilize the maximum axial dimension allowed by the outer casing 1. This has minimal impact on the electromagnetic performance of the motor and can accommodate the installation space of the motor.

[0112] Please see Figure 7 and Figure 8 The cross-section of the sealing ring 5 can be Y-shaped or H-shaped. The opening of the Y-shaped sealing ring 5 faces the oil cavity side. Under the action of oil pressure, the lip of the sealing ring 5 can be squeezed to the other side due to the oil pressure, thereby ensuring a better sealing effect and making the seal more reliable. Compared with the Y-shaped sealing ring 5, the H-shaped sealing ring 5 has openings on both sides, which can achieve bidirectional sealing.

[0113] Please see Figure 3 In some possible embodiments, the rotor assembly 3 includes a rotor shaft 31 and a rotor core 32; the rotor shaft 31 is rotatably connected inside the outer casing 1; the rotor shaft 31 is provided with a shaft oil passage 311 extending axially thereon, and the oil inlet end of the shaft oil passage 311 is connected to the second oil inlet 12; the rotor core 32 is sleeved and fixed on the rotor shaft 31; the rotor core 32 is provided with a core oil passage 321, and the oil inlet end of the core oil passage 321 is connected to the oil outlet end of the shaft oil passage 311, and the oil outlet end is connected to the inner cavity 14; wherein, the rotor oil passage includes the shaft oil passage 311 and the core oil passage 321.

[0114] In this embodiment of the application, by setting a shaft oil passage 311 on the rotor shaft 31 and a core oil passage 321 on the rotor core 32, the cooling oil can pass through the rotor assembly 3 sequentially from the second oil inlet 12, the shaft oil passage 311 and the core oil passage 321, thereby achieving cooling of the rotor core 32 and the rotor shaft 31.

[0115] Specifically, the rotor shaft 31 and the rotor core 32 can be fixed by means of interference fit or bolt connection, so that when the rotor shaft 31 rotates, it can drive the rotor core 32 to rotate synchronously.

[0116] For example, the rotor shaft 31 has an axially extending oil passage 311, and a first radial oil passage 312 extending radially is also provided on the rotor shaft 31. The first radial oil passage 312 is used to connect to the oil inlet end of the rotor core oil passage 321. Specifically, each set of first radial oil passages 312 includes multiple radially extending oil channels. The multiple radially extending oil channels are distributed circumferentially along the rotor shaft 31 to guide the oil from the multiple radially extending oil channels into the rotor core oil passage 321.

[0117] For example, there are two rotating core oil passages 321. The two rotating core oil passages 321 are distributed at intervals along the axial direction of the rotor shaft 31. Each rotating core oil passage 321 corresponds to a set of first radial oil passages 312. The oil enters the rotating core oil passage 321 from the rotating shaft oil passage 311 through the corresponding first radial oil passage 312.

[0118] Specifically, both rotor core oil passages 321 are U-shaped oil passages, and the oil inlet ends of both U-shaped oil passages are connected to the rotor shaft oil passage 311 through the first radial oil passage 312. The oil inlet ends of the two rotor core oil passages 321 are spaced apart along the axial direction of the rotor shaft 31, and the oil outlet ends are located at the two ends of the axial direction of the rotor core 32, so that the U-shaped opening directions of the two U-shaped oil passages are opposite.

[0119] Furthermore, oil-throwing plates are provided on both sides of the rotor core 32. The oil-throwing plates are provided with oil-throwing holes that are connected to the oil passage 321 of the rotor core. The oil-throwing holes are arranged to pass through the rotor shaft 31 along the axial direction so as to throw the oil out of the rotor core 32 along the axial direction of the rotor shaft 31.

[0120] In addition, the rotor shaft 31 is also provided with a second radial oil passage 313. There are two sets of the second radial oil passage 313. The two sets of the second radial oil passage 313 are respectively located on both sides of the stator core 21 and close to the rotating bearings on the rotor shaft 31. The oil outlet of the second radial oil passage 313 is connected to the inner cavity 14. The cooling oil can be directly thrown from the second radial oil passage 313 into the inner cavity 14 to cool the rotating bearings on both sides of the stator core 21.

[0121] Understandably, the cooling oil enters from the second oil inlet 12 at the end of the outer casing 1 and flows into the rotor shaft oil passage 311 extending axially from the center of the rotor shaft 31. When the oil flows to the corresponding axial position of the rotor core 32, it enters the interior of the rotor core 32 through the radial through hole opened on the rotor shaft 31. The oil flows in the rotor core oil passage 321, directly scouring the silicon steel sheets and the internal permanent magnets, carrying away the heat generated by eddy current loss and hysteresis loss. Under the action of the huge centrifugal force generated by the high-speed rotation of the rotor, the oil is forced out from the outer end of the rotor core oil passage 321 and sprayed into the inner cavity 14 as a high-speed oil mist or oil droplet, and finally falls to the bottom of the inner cavity 14 under the action of gravity.

[0122] Optionally, the rotor core 32 includes a plurality of second core laminations stacked sequentially along the axial direction of the rotor shaft 31. Each second core lamination is provided with a second oil passage suitable for oil to pass through. The plurality of second oil passages on the plurality of second core laminations are connected sequentially along the axial direction of the rotor assembly 3 and form a zigzag-shaped rotor core oil passage 321 so that the oil can be guided from the inside of the rotor core 32 to the outside of the rotor core 32.

[0123] In addition, the second core lamination is also provided with a weight removal hole to achieve the weight reduction of the motor assembly. During the stacking process of the second core lamination, there will be gaps between the laminations. A small amount of oil may enter the weight removal hole through the gaps between the laminations and accumulate. Optionally, an oil hole corresponding to the weight removal hole of the rotor core 32 is provided on the oil slinger plate to facilitate the smooth discharge of oil in the weight removal hole. This can reduce the noise generated by the oil accumulated in the weight removal hole during operation and also play a positive role in the internal heat conduction of the rotor.

[0124] The oil flow path of the motor assembly in this application is specifically divided into two paths: one is the cooling oil flow direction of the outer cavity 13, which is defined as the first path, and the second is the cooling oil flow direction of the inner cavity 14, which is defined as the second path.

[0125] In the first path, the cooling oil is injected from the first oil inlet 11 and flows downwards into the outer cavity 13. The two end extensions 41 of the winding assembly 4 inside the outer cavity 13 are wound around the support ring 15 fixed to the inner wall of the housing. After the oil enters the outer cavity, it immerses the winding assembly 4 and cools the stator core 21 body. The oil flows axially from one end of the stator assembly 2 to the other end through the stator core oil passage 211, directly carrying away the heat generated by the hysteresis loss and eddy current loss of the silicon steel sheet. The immersed oil carries away the heat generated by the copper loss of the winding assembly 4. At the same time, some of the heat is transferred to the outer shell 1 and dissipated outwards through the solid phase heat conduction path of the support ring 15.

[0126] After cooling the winding assembly 4 and the stator core 21, the heated oil overflows from the first oil outlet 17 located at the top of the other axial end of the stator assembly 2 and enters the upper oil passage 1611 embedded in the upper part of the side wall of the outer casing 1. The upper oil passage 1611 extends vertically, and the oil flows downward along the upper oil passage 1611 under the dominant force of gravity, and then the oil enters the arc-shaped oil passage 1612.

[0127] The arc-shaped oil passage 1612 is arranged around the side wall of the outer casing 1 surrounding the rotor assembly 3, extending in an arc shape. Its purpose is to avoid the central rotor assembly 3 to save axial space, while significantly extending the flow path of the first oil passage 161. The oil extends circumferentially in a semi-circular shape within the arc-shaped oil passage 1612. The heat carried by the oil is conducted through the metal of the side wall of the outer casing 1 to the external heat dissipation fins or cooling water jacket of the casing, achieving pre-cooling of the returning oil.

[0128] The pre-cooled oil enters the lower oil passage 1613 from the end of the arc-shaped oil passage 1612. The lower oil passage 1613 extends vertically, and the oil continues to flow downward to the bottom of the outer shell 1 under the action of gravity, and finally flows into one end of the U-shaped second oil passage 162.

[0129] In the second path, the cooling oil enters the rotor shaft 31 from the second oil inlet 12 and first flows axially along the shaft oil passage 311 at the center of the rotor shaft 31. The shaft oil passage 311 extends along the axial center of the rotor shaft 31, and the oil initially cools the rotor shaft 31 during the flow inside the shaft.

[0130] When the oil flows to the axial position corresponding to the rotor core 32, it enters the rotor core oil passage 321 inside the rotor core 32 through the first radial oil passage 312 and the second radial oil passage 313 opened on the rotor shaft 31 wall, cooling the rotor core 32. Multiple first radial oil passages 312 are evenly distributed along the circumference to ensure dynamic balance. As the oil flows within the rotor core oil passage 321, it carries away heat from the rotor core 32. Under the centrifugal force generated by the high-speed rotation of the rotor, the oil is thrown out from the oil outlet end on the outer circumference of the rotor core 32 and enters the inner cavity 14.

[0131] The oil thrown into the inner cavity 14 falls to the bottom of the inner cavity 14 under the action of gravity. The oil at the bottom flows out through the second oil outlets 18 located at both ends of the bottom of the inner cavity 14 and enters the top openings at both ends of the U-shaped second oil channel 162 embedded in the bottom shell wall of the outer shell 1.

[0132] Finally, the mixed oil flows along the bottom of the U-shaped horizontal section towards the return port 19, and the final mixed oil is discharged to the external cooler or oil tank through the return port 19 located at the lowest point of the U-shape, completing the entire cycle.

[0133] This application uses a radial sealing fit between the support ring 15 and the end ring 22 to divide the receiving cavity of the outer casing 1 into two independent outer cavity 13 and inner cavity 14, and correspondingly provides a first oil inlet 11 and a second oil inlet 12, thus constructing two independently operating cooling circulation loops. Throughout the cooling process, the oil in the outer cavity 13 and the inner cavity 14 does not flow between them, and the cooling parameters on the stator assembly 2 side and the rotor assembly 3 side can be independently adjusted according to the operating conditions, achieving precise temperature control for different heat sources in the motor.

[0134] Furthermore, this application places the first oil inlet 11 at the top of the outer casing 1 and the second oil inlet 12 at the end of the outer casing 1, with two independent oil inlets. This avoids the flow competition and pressure imbalance problems caused by a single oil inlet when distributed to multiple branches, ensuring stable oil supply pressure for each cooling circuit under different operating conditions. Simultaneously, the first oil outlet 17 is located at the top of the outer cavity 13, and the second oil outlet 18 is located at the bottom of the inner cavity 14. The oil outlet channel 16 is integrated into the shell wall of the outer casing 1 and ultimately discharged through a single return oil outlet 19, achieving a dual-inlet, single-outlet oil port layout. This reduces the number of oil pipe joints outside the outer casing 1, simplifies the vehicle's piping connections, reduces the risk of system leakage, and makes the external interface of the motor assembly simpler, facilitating its arrangement within the limited vehicle cabin space.

[0135] Based on the same inventive concept, this application also provides a vehicle that includes the above-described motor assembly.

[0136] The vehicle provided in this application, having the aforementioned motor assembly, possesses all the beneficial effects of the aforementioned motor assembly. It enables independent cooling of the stator assembly 2 and the rotor assembly 3, avoids the accumulation of cooling oil in the motor housing cavity, reduces the risk of reverse heating of the bottom stator core 21 or winding assembly 4, significantly improves the cooling efficiency and cooling uniformity of the motor, and reduces the risk of local overheating.

[0137] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A motor assembly, characterized in that, include: The outer casing (1) has a receiving cavity; the outer casing (1) is provided with a first oil inlet (11) and a second oil inlet (12); A stator assembly (2) is placed inside the receiving cavity; the radial inner edge of the stator assembly (2) extends along its axial direction to abut against the two side walls of the receiving cavity respectively, so as to divide the receiving cavity into an inner cavity (14) and an outer cavity (13) with independent inner and outer sides; the outer cavity (13) is connected to the first oil inlet (11); A rotor assembly (3) is placed inside the inner cavity (14) and passes through the stator assembly (2); the axial ends of the rotor assembly (3) are rotatably connected to the outer shell (1); the rotor assembly (3) is provided with a rotor oil passage, the oil inlet end of the rotor oil passage is connected to the second oil inlet (12), and the oil outlet end is connected to the inner cavity (14); and The winding assembly (4) is wound inside the stator assembly (2) and placed inside the outer cavity (13); The outer shell (1) has an oil outlet channel (16) inside its shell wall. The oil outlet channel (16) has a first oil outlet (17) that connects to the outer cavity (13), a second oil outlet (18) that connects to the inner cavity (14), and an oil return port (19) that extends to the outside of the outer shell (1).

2. The motor assembly as described in claim 1, characterized in that, In the vertical direction of the outer casing (1), the first oil outlet (17) is positioned above the top of the winding assembly (4).

3. The motor assembly as described in claim 2, characterized in that, The first oil inlet (11) is located at the top of the outer shell (1) and extends downward into the outer cavity (13); The first oil outlet (17) is located at the top of the outer cavity (13) and extends along the axial direction of the rotor assembly (3); The first oil outlet (17) and the first oil inlet (11) are respectively located at the two ends of the axial direction of the stator assembly (2).

4. The motor assembly as described in any one of claims 1-3, characterized in that, The oil outlet channel (16) includes: The first oil passage (161) extends vertically within the side wall of the outer shell (1); the upper end of the first oil passage (161) is provided with the first oil outlet (17); The second oil passage (162) is located inside the bottom shell wall of the outer shell (1); one end of the second oil passage (162) extends upward and is provided with the second oil outlet (18); the extended end of the second oil passage (162) is also connected to the lower end of the first oil passage (161); the bottom of the second oil passage (162) is provided with the return oil port (19).

5. The motor assembly as described in claim 4, characterized in that, The first oil passage (161) includes: An upper oil passage (1611) is provided, extending vertically, and the upper oil passage (1611) is provided with the first oil outlet (17); An arc-shaped oil passage (1612) is arranged around the periphery of the rotor assembly (3) and communicates with the lower end of the upper oil passage (1611); and The lower oil passage (1613) is connected at one end to the arc-shaped oil passage (1612) and at the other end extends downward to connect with the second oil passage (162).

6. The motor assembly as described in claim 4, characterized in that, The inner cavity (14) is provided with a set of second oil outlets (18) at both ends along the axial direction of the rotor assembly (3). The second oil passage (162) is a U-shaped oil passage with an upward opening. The two ends of the U-shaped oil passage are connected to the two sets of second oil outlets (18), and one end of the U-shaped oil passage is also connected to the lower end of the first oil passage (161).

7. The motor assembly as described in claim 1, characterized in that, The stator assembly (2) includes: The stator core (21) is arranged around the rotor assembly (3); the stator core (21) is provided with an axially penetrating mounting groove and an axially extending stator core oil passage (211); Two end rings (22) are clamped relative to each other at both ends of the stator core (21), and the radial inner edge of the end rings (22) extends along the axial direction of the rotor assembly (3) to abut against the cavity wall of the receiving cavity; The winding assembly (4) is wound in the mounting groove and extends out of the mounting groove at both ends to form an extension section (41), which is wound around the extension end of the end ring (22).

8. The motor assembly as described in claim 7, characterized in that, The inner wall of the receiving cavity is provided with a support ring (15) corresponding to the end ring (22). The support ring (15) extends axially into the end ring (22) and is close to the inner wall of the end ring (22) to separate the outer cavity (13) and the inner cavity (14). A sealing ring (5) is provided between the outer wall of the support ring (15) and the inner wall of the end ring (22). The extension section (41) is wrapped around the support ring (15).

9. The motor assembly as described in claim 1, characterized in that, The rotor assembly (3) includes: The rotor shaft (31) is rotatably connected inside the outer casing (1); the rotor shaft (31) is provided with a shaft oil passage (311) extending along its axial direction, and the oil inlet end of the shaft oil passage (311) is connected to the second oil inlet (12); A rotor core (32) is sleeved and fixed on the rotor shaft (31); the rotor core (32) is provided with a rotor core oil passage (321), the oil inlet of the rotor core oil passage (321) is connected to the oil outlet of the rotor shaft oil passage (311), and the oil outlet is connected to the inner cavity (14); The rotor oil circuit includes the shaft oil circuit (311) and the iron core oil circuit (321).

10. A vehicle, characterized in that, Includes the motor assembly as described in any one of claims 1-9.

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