Electric drive system and vehicle

Abstract

The invention discloses an electric drive system and a vehicle, the electric drive system comprises a motor and a magnetic fluid sealing device, the motor comprises a shell internally provided with a mounting cavity, the mounting cavity is internally provided with at least a moving part and is suitable for accommodating a phase change medium so as to at least cool the moving part, the phase change medium can be converted between gas and liquid phases under the influence of heat, and the magnetic fluid sealing device is used for sealing the moving part. The magnetic fluid sealing device is arranged between the moving part and the shell so as to prevent leakage of the phase change medium. The phase change medium is adopted for heat exchange of the motor, the heat dissipation effect of the motor is improved, the heat dissipation uniformity of the motor is improved, the service life of the motor is guaranteed, and then the service life of the electric drive system is prolonged. The magnetic fluid sealing device is further arranged between the moving part and the shell of the motor, so that non-contact sealing between the moving part and the shell is achieved, leakage of the phase change medium is prevented, abrasion of the magnetic fluid sealing device is small, and the sealing reliability between the moving part and the shell is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and more particularly to an electric drive system and a vehicle. Background Technology

[0002] As the core power component of new energy vehicles, the power performance of the vehicle mainly depends on the performance of the electric drive system itself. When the electric drive system's motor is working, both the stator and rotor assemblies generate heat, and the motor needs to be cooled in order to ensure its working performance.

[0003] In related technologies, motors are usually cooled by cooling oil. However, the heat absorption effect of cooling oil is limited, which affects the heat dissipation efficiency of the motor and thus the service life of the motor, and consequently the service life of the electric drive system. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes an electric drive system in which the motor has good heat dissipation and high sealing reliability, which is beneficial to improving the service life of the motor, thereby improving the service life of the electric drive system.

[0005] An electric drive system according to an embodiment of the present invention includes: a motor, the motor including a housing having an internally formed mounting cavity, the mounting cavity having at least one moving part and adapted to accommodate a phase change medium for at least cooling the moving part, the phase change medium being capable of transforming between gas and liquid phases under the influence of heat; and a magnetohydrodynamic sealing device disposed between the moving part and the housing to prevent leakage of the phase change medium.

[0006] According to the electric drive system of this application embodiment, by using a phase change medium for heat exchange with the motor, it is beneficial to improve the heat dissipation effect of the motor and the heat dissipation uniformity of the motor, ensuring the service life of the motor, and thus improving the service life of the electric drive system. By further setting a magnetic fluid sealing device between the moving parts of the motor and the housing, a non-contact seal between the moving parts and the housing is achieved, preventing leakage of the phase change medium and thus preventing the loss of the phase change medium. At the same time, it can ensure the smooth movement of the moving parts. Furthermore, since the magnetic fluid sealing device has less wear, it is beneficial to ensure the sealing reliability between the moving parts and the housing, reducing the maintenance frequency, and thus reducing the maintenance frequency of the electric drive system.

[0007] According to some embodiments of the present invention, the motor further includes: a stator assembly, the stator assembly being fixedly installed within the housing, and the stator assembly including a stator and stator end plates, stator end plates being provided at both axial ends of the stator, the stator end plates being used to limit the stator; the moving component includes: a rotor assembly, the rotor assembly being disposed within the stator assembly, the rotor assembly being rotatable relative to the stator assembly, the rotor assembly including a rotor, a rotating shaft and dynamic balance plates provided at both axial ends of the rotor, the rotating shaft being disposed through the rotor along the axial direction of the rotor, and at least a portion of the rotating shaft extending out from the housing, the magnetohydrodynamic sealing device being disposed between the rotating shaft and the housing.

[0008] According to some embodiments of the present invention, the housing includes: a housing body, a front end cover and a rear end cover, the front end cover and the rear end cover are respectively disposed on both axial sides of the housing body, and the magnetohydrodynamic sealing device is respectively provided between the front end cover and the rotating shaft and between the rear end cover and the rotating shaft.

[0009] According to some embodiments of the present invention, the magnetic fluid sealing device includes: a conductive coil that generates a magnetic field when energized, wherein the conductive coil is disposed between the housing and the rotating shaft in the radial direction of the rotating shaft, and is spaced apart from the rotating shaft and the housing respectively; a magnetic conductor, wherein the magnetic conductor is disposed on both sides of the conductive coil in the axial direction parallel to the rotating shaft, and the side of the magnetic conductor facing the housing is adapted to seal with the housing; and a magnetic fluid, wherein the magnetic fluid is disposed between the rotating shaft and the magnetic conductor.

[0010] According to some embodiments of the present invention, the rotating shaft has a toothed groove on the side facing the housing, the magnetic conductive element has a toothed tip adapted to engage with the toothed groove, and the magnetic fluid is disposed in the toothed groove. The rotating shaft includes: a rotor shaft connected to the rotor, with both ends of the rotor shaft respectively mounted to the front end cover and the rear end cover via bearings, one end of the rotor shaft extending from the front end cover, and having the toothed groove on the side facing the front end cover; a spline shaft disposed within the rotor shaft, with both ends of the spline shaft extending from the front end cover and the rear end cover respectively, and having the toothed groove on the side facing the rear end cover; and an intermediate shaft disposed between the rotor shaft and the spline shaft, with at least a portion of the end of the intermediate shaft facing the rear end cover located between the spline shaft and the rotor shaft in an axial direction parallel to the rotating shaft, and spaced apart from the rotor shaft.

[0011] According to some embodiments of the present invention, the stator end plate includes: a first portion, which is disposed opposite to the stator and used to limit the stator in an axial direction parallel to the stator; and a second portion, which is connected to the radially inner end of the first portion and extends toward the housing in an axial direction parallel to the stator, the housing having an extending protrusion disposed opposite to the second portion, and an oil ring being provided between the extending protrusion and the second portion for sealing the second portion and the extending protrusion.

[0012] According to some embodiments of the present invention, the stator end plate includes a first end plate and a second end plate. The first end plate is disposed on the side of the stator facing the rear end plate, and the second end plate is disposed on the side of the stator facing the front end plate. A first chamber is defined between the first end plate and the housing. The first chamber is located on the side of the first end plate near the rear end plate. A second chamber is defined between the second end plate and the housing. The second chamber is located on the side of the second end plate near the front end plate. The first chamber and the second chamber communicate with each other. The housing body is provided with a medium inlet and a medium outlet. The medium inlet is used to allow the phase change medium to flow into the mounting cavity. The medium inlet is disposed opposite to and communicates with the first chamber. The medium outlet is disposed opposite to and at least communicates with the second chamber.

[0013] According to some embodiments of the present invention, a third chamber is defined between the second end plate, the housing, and the dynamic balance plate disposed on the same side as the second end plate. The third chamber is spaced apart from the second chamber and is respectively connected to the medium inlet and the medium outlet.

[0014] According to some embodiments of the present invention, the electric drive system further includes: a heat exchange assembly comprising a condenser and a radiator; the medium outlet comprising: a first liquid outlet located at the bottom of the second chamber and used to connect the second chamber to the inlet end of the radiator; a first gas outlet located at the top of the second chamber and used to connect the second chamber to the inlet end of the condenser; a second liquid outlet located at the bottom of the third chamber and used to connect the third chamber to the inlet end of the radiator; and a second gas outlet located at the top of the third chamber and used to connect the third chamber to the inlet end of the radiator; wherein the outlet end of the condenser is connected to the inlet end of the radiator, and the outlet end of the radiator is connected to the medium inlet.

[0015] According to some embodiments of the present invention, a baffle is provided on the side of the conductive coil facing the spline shaft, the baffle being used to space the conductive coil from the spline shaft and define a first heat exchange cavity communicating with the first chamber; the magnetic conductive element is spaced apart from the bearing so that a second heat exchange cavity is formed between the magnetic conductive element, the bearing and the rotating shaft, the second heat exchange cavity communicating with the first heat exchange cavity and the third chamber respectively.

[0016] According to some embodiments of the present invention, the motor is provided with a heat exchange channel, the heat exchange channel comprising: a first channel section, the first channel section being disposed through the stator assembly in an axial direction parallel to the stator assembly to connect the first chamber and the second chamber; a second channel section, the second channel section being disposed within the rear end plate, with one end of the second channel section communicating with the first chamber and the other end of the second channel section communicating with both the first and second heat exchange chambers; a third channel section, the third channel section being disposed on a magnetic guide near the bearing, and the third channel section being disposed through the magnetic guide in an axial direction parallel to the rotating shaft, the third channel section being used to connect the first and second heat exchange chambers; and a fourth channel section, the fourth channel section being disposed on the rotor assembly and extending bently on the rotor assembly, the fourth channel section being used to connect the second heat exchange chamber and the third chamber; wherein the flow cross-sectional area of ​​the fourth channel section is at least smaller than the flow cross-sectional area of ​​the second channel section.

[0017] According to some embodiments of the present invention, a switching valve is provided at the first liquid outlet, the switching valve being adapted to open when the temperature of the phase change medium reaches a preset temperature, the preset temperature being greater than the critical temperature at which the phase change medium undergoes a phase change.

[0018] The second objective of this invention is to provide a vehicle.

[0019] The vehicle according to an embodiment of the present invention includes the electric drive system described above.

[0020] The vehicle described above has the same advantages as the electric drive system mentioned above, which will not be repeated here.

[0021] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the electric drive system according to an embodiment of the present invention; Figure 2 A schematic diagram of the structure of the motor described in this embodiment of the invention; Figure 3 for Figure 2 Enlarged view of point A in the middle; Figure 4 for Figure 2 Enlarged view of point B in the middle.

[0023] Figure label: Electric drive system 100 Motor 110 Shell 111, shell body 1111, front cover 1112, rear cover 1113, extension protrusion 1114 Rotor assembly 112, rotor 1121 Rotor shaft 1122, rotor shaft 1, splined shaft 2, intermediate shaft 3 Dynamic balancing plate 1123 Stator assembly 113, stator 1131, Part 1 11321, Part 2 11322, First End Plate 11323, Second End Plate 11324 Bearing 114, Oil ring 115, Magnetic fluid sealing device 120, conductive coil 121, magnetic conductive element 122 Seals 123 First chamber a, second chamber b, medium inlet c, first liquid outlet d1, first gas outlet d2, second liquid outlet d3, second gas outlet d4, third chamber e, first heat exchange chamber f, second heat exchange chamber g, second flow channel section h2, fourth flow channel section h4 Condenser 151, Radiator 152 Baffle 160, switch valve 170. Detailed Implementation

[0024] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0025] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not 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 the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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 an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] The following reference Figures 1-4 An electric drive system 100 according to an embodiment of the present invention is described.

[0027] Combination Figures 1 to 3 According to an embodiment of the present invention, the electric drive system 100 includes a motor 110. The motor 110 includes a housing 111 with an internal mounting cavity. At least one moving part is provided in the mounting cavity. That is, the housing 111 can provide mounting space for the moving part and can protect the parts disposed inside it, thereby reducing the risk of damage to the motor 110. The moving part can move relative to the housing 111. For example, the moving part can be a rotor assembly 112, which can rotate relative to the housing 111.

[0028] Furthermore, the mounting cavity is suitable for accommodating a phase change medium to at least cool moving parts. The phase change medium can transform between gas and liquid phases under the influence of heat. The phase change medium can not only absorb sensible heat, but also absorb latent heat during the transformation between gas and liquid phases, making its heat absorption capacity much greater than that of other liquids. This effectively improves the heat dissipation effect on the motor 110. Moreover, the phase change process of the phase change medium can occur in the area in contact with the high-temperature surface. The bubbles generated when it boils can agitate the fluid to improve the heat exchange uniformity of the phase change medium on the motor 110, ensure the consistency of thermal expansion of each component of the motor 110, reduce thermal stress, and thus help extend the service life of the motor 110. At the same time, since the phase change of the phase change medium occurs at a constant temperature point, it helps to ensure the temperature stability of the components that exchange heat with it (such as moving parts). To ensure smooth movement of the moving parts relative to the housing 111, a gap is typically formed between the moving parts and the housing 111. Considering that the phase change medium is prone to leakage through this gap, potentially affecting the heat dissipation efficiency of the motor 110, the electric drive system 100 of this application also includes a magnetic fluid sealing device 120. The magnetic fluid sealing device 120 is located between the moving parts and the housing 111. It can move with the moving parts and achieves a non-contact seal between the moving parts and the housing 111, preventing phase change medium leakage while ensuring smooth movement of the moving parts. Furthermore, compared to conventional sealing rings, the magnetic fluid sealing device 120 can adapt to high-speed movement of the moving parts and generates less wear, effectively ensuring the sealing reliability of the magnetic fluid sealing device 120 and reducing maintenance frequency.

[0029] In related technologies, motors are usually cooled by cooling oil. However, the heat absorption effect of cooling oil is limited, which affects the heat dissipation efficiency of the motor and thus the service life of the motor, and consequently the service life of the electric drive system.

[0030] This application utilizes a phase change medium for heat exchange in the motor 110, which improves the heat dissipation effect and uniformity of the motor 110, ensuring its service life and consequently extending the service life of the electric drive system 100. Furthermore, by installing a magnetic fluid sealing device 120 between the moving parts of the motor 110 and the housing 111, a non-contact seal is achieved between the moving parts and the housing 111, preventing leakage of the phase change medium and thus preventing its loss. This also ensures smooth movement of the moving parts. Additionally, the magnetic fluid sealing device 120 experiences less wear, which helps ensure the reliability of the seal between the moving parts and the housing 111, reducing maintenance frequency and consequently lowering the maintenance frequency of the electric drive system 100.

[0031] Combination Figure 2 and Figure 3 In some embodiments of the present invention, the motor 110 further includes a stator assembly 113, which is fixedly installed inside the housing 111. Specifically, the stator assembly 113 can be installed inside the housing 111 by press fitting, and the stator assembly 113 includes a stator 1131 and stator end plates. The stator end plates are respectively provided at both axial ends of the stator 1131. The stator end plates are used to limit the stator 1131. Specifically, the stator end plates can limit the stator 1131 in the axial direction and the radial direction to prevent the stator 1131 from being displaced inside the housing 111 and improve the assembly stability of the stator 1131.

[0032] The moving parts include: a rotor assembly 112, which is disposed within a stator assembly 113 and can rotate relative to the stator assembly 113. The rotor assembly 112 includes a rotor 1121, a rotating shaft 1122, and dynamic balance plates 1123 disposed at both axial ends of the rotor 1121. The rotating shaft 1122 is disposed through the rotor 1121 along the axial direction of the rotor 1121. The stator 1131 generates a magnetic field to drive the rotor 1121 to rotate. The rotor 1121 is connected to the rotating shaft 1122 to drive the rotating shaft 1122 to rotate. At least a portion of the rotating shaft 1122 extends out of the housing 111 to facilitate connection of the rotating shaft 1122 to an external load, thereby facilitating the output of mechanical energy through the rotating shaft 1122.

[0033] The dynamic balance plates 1123 located at both ends of the rotor 1121 can adjust the mass distribution of the rotor 1121, ensure the balance of the rotor 1121 when it rotates, prevent the wear of components such as the shaft 1122 due to the imbalance of the rotor 1121, extend the service life of the motor 110, improve the energy efficiency of the motor 110, and reduce energy loss.

[0034] The magnetic fluid sealing device 120 is disposed between the rotating shaft 1122 and the housing 111. Since the rotating shaft 1122 rotates relative to the housing 111, a gap is formed between the rotating shaft 1122 and the housing 111 in order to ensure the smooth rotation of the rotating shaft 1122. The phase change medium can easily leak from the housing 111 through the gap between the rotating shaft 1122 and the housing 111. Therefore, by disposing of the magnetic fluid sealing device 120 between the rotating shaft 1122 and the housing 111, a non-contact seal between the rotating shaft 1122 and the housing 111 can be achieved. This can prevent the leakage of the phase change medium and ensure the smooth movement of the rotating shaft 1122.

[0035] In some specific embodiments, the stator end plate can be formed as a PPS+40GF material part, that is, a glass fiber reinforced polyphenylene sulfide composite material part, to improve the structural strength of the stator end plate and reduce the risk of deformation of the stator end plate.

[0036] Combination Figure 2 and Figure 3 In some embodiments of the present invention, the housing 111 includes: a housing body 1111, a front end cover 1112, and a rear end cover 1113. The front end cover 1112 and the rear end cover 1113 are respectively disposed on both axial sides of the housing body 1111 and together define a mounting cavity. One end of the rotating shaft 1122 can extend from the housing 111 through the front end cover 1112, and the other end of the rotating shaft 1122 extends from the housing 111 through the rear end cover 1113. To ensure the smooth rotation of the rotating shaft 1122, the rotating shaft 1122 and the front end cover 1113 are connected. A gap is formed between the cover 1112 and the rear cover 1113. In order to prevent leakage of the phase change medium from the rotation shaft 1122 to the front cover 1112 and the rear cover 1113, a magnetic fluid sealing device 120 is provided between the front cover 1112 and the rotation shaft 1122 and between the rear cover 1113 and the rotation shaft 1122, so that a non-contact seal is formed between the rotation shaft 1122 and the front cover 1112 and the rear cover 1113, so as to ensure the smooth rotation of the rotation shaft 1122 while preventing the leakage of the phase change medium.

[0037] The magnetic fluid sealing device 120 can be pre-installed on the front cover 1112 and the rear cover 1113 respectively, and then the front cover 1112 and the rear cover 1113 are connected to the shell body 1111 respectively by bolts to realize the installation of the magnetic fluid sealing device 120.

[0038] In some embodiments of the present invention, the front cover 1112 and the shell body 1111 are formed as one piece to simplify the assembly steps of the motor 110 and improve the production and assembly efficiency of the motor 110.

[0039] Combination Figure 2 and Figure 3 In some embodiments of the present invention, the magnetic fluid sealing device 120 includes: a magnetic conductor 122, a magnetic fluid, and a conductive coil 121 that generates a magnetic field after being energized. In the radial direction of the rotating shaft 1122, the conductive coil 121 is disposed between the housing 111 and the rotating shaft 1122, and is spaced apart from the rotating shaft 1122 and the housing 111 respectively, so as to prevent the conductive coil 121 from being damaged due to the rotation of the rotating shaft 1122 or the vibration of the housing 111, and at the same time, it can reduce the transfer of heat generated by the conductive coil 121 to the housing 111 and the rotating shaft 1122.

[0040] In the axial direction parallel to the rotating shaft 1122, the magnetic conductor 122 can be sleeved on the rotating shaft 1122, and the magnetic conductor 122 is respectively disposed on both sides of the conductive coil 121. The side of the magnetic conductor 122 facing the housing 111 is suitable for sealing with the housing 111. For example, the side of the magnetic conductor 122 facing the housing 111 can be provided with a sealing member 123. The sealing member 123 is sandwiched between the magnetic conductor 122 and the housing 111 to achieve a sealing fit between the magnetic conductor 122 and the housing 111. The magnetic fluid is disposed between the rotating shaft 1122 and the magnetic conductor 122.

[0041] When the conductive coil 121 is energized, it generates a magnetic field. The magnetic conductor 122 can serve as a magnetic path for the magnetic field, so that the magnetic field is mainly concentrated in the gap area between the rotating shaft 1122 and the magnetic conductor 122. The magnetic fluid is a liquid functional material that responds to the magnetic field. Under the magnetic force of the magnetic field, the magnetic fluid can be adsorbed in the gap between the rotating shaft 1122 and the magnetic conductor 122, and under the influence of the magnetic field gradient, a continuous and stable magnetic fluid sealing film is formed. The magnetic fluid sealing film can fill the gap between the rotating shaft 1122 and the magnetic conductor 122. When the rotating shaft 1122 rotates, the magnetic fluid sealing film will not leak with the rotation of the rotating shaft 1122 due to the constraint of the magnetic force. At the same time, its fluid characteristics can adapt to the rotation of the rotating shaft 1122, thereby achieving dynamic sealing between the housing 111 and the rotating shaft 1122.

[0042] In some specific embodiments, the magnetic conductor 122 may be configured as a pole shoe.

[0043] Combination Figure 2 and Figure 3 In some embodiments of the present invention, the rotating shaft 1122 is provided with a toothed groove on the side facing the housing 111, the magnetic conductive element 122 is formed with a tooth tip, the tooth tip is adapted to cooperate with the toothed groove, and the toothed groove is provided with magnetic fluid. That is to say, the toothed groove can play the role of storing magnetic fluid, which is beneficial to increasing the content of magnetic fluid. Furthermore, the cooperation between the toothed groove and the tooth tip helps to reduce the loss of magnetic fluid, thereby preventing the magnetic fluid sealing device 120 from failing.

[0044] The rotating shaft 1122 includes a rotor shaft 1, a splined shaft 2, and an intermediate shaft 3. The rotor shaft 1 is connected to the rotor 1121, and both ends of the rotor shaft 1 are respectively mounted on the front end cover 1112 and the rear end cover 1113 via bearings 114. One end of the rotor shaft 1 extends out from the front end cover 1112, and a toothed groove is provided on the side facing the front end cover 1112. The toothed groove can cooperate with the tip of the magnetic guide 122 of the magnetic fluid sealing device 120 provided on the side of the front end cover 1112, and the magnetic fluid can be disposed on the toothed groove of the rotor shaft 1 to achieve a seal between the rotating shaft 1122 and the front end cover 1112.

[0045] Splined shaft 2 is located inside rotor shaft 1, and both ends of splined shaft 2 extend from front end cover 1112 and rear end cover 1113 respectively. Splined shaft 2 has a toothed groove on the side facing rear end cover 1113. The toothed groove can cooperate with the tip of the magnetic guide 122 of the magnetic fluid sealing device 120 located on the side of rear end cover 1113. Magnetic fluid can be disposed on the toothed groove of splined shaft 2 to achieve a seal between rotor shaft 1122 and rear end cover 1113.

[0046] The intermediate shaft 3 is located between the rotor shaft 1 and the spline shaft 2. In the axial direction parallel to the rotating shaft 1122, at least a portion of the end of the intermediate shaft 3 facing the rear end cover 1113 is located between the spline shaft 2 and the rotor shaft 1 and is spaced apart from the rotor shaft 1. The gap formed between the intermediate shaft 3 and the rotor shaft 1 allows the phase change medium to flow through the rotating shaft 1122, so that the phase change medium can dissipate heat from the rotating shaft 1122.

[0047] The sealing pressure can be adjusted by changing the number of teeth on the magnetic conductor 122. It is understood that the specific number of teeth on the magnetic conductor 122 can be determined according to actual production requirements, and no specific limit is made here.

[0048] Combination Figure 2 and Figure 4 In some embodiments of the present invention, the stator end plate includes: a first portion 11321 and a second portion 11322. In an axial direction parallel to the stator 1131, the first portion 11321 is disposed opposite to the stator 1131 and is used to limit the stator 1131. The second portion 11322 is connected to the radial inner end of the first portion 11321 and extends toward the housing 111 in an axial direction parallel to the stator 1131. The housing 111 has an extension protrusion 1114. The extension protrusion 1114 is disposed opposite to the second portion 11322. An oil ring 115 is provided between the extension protrusion 1114 and the second portion 11322. The oil ring 115 is used to seal the second portion 11322 and the extension protrusion 1114.

[0049] Specifically, in the axial direction parallel to the rotating shaft 1122, an extension protrusion 1114 is formed on one side wall of the front end cover 1112 and the rear end cover 1113 located in the mounting cavity. The extension protrusion 1114 extends toward the stator end plate in the axial direction parallel to the rotating shaft 1122. The second part 11322 extends from the first part 11321 in the axial direction parallel to the rotating shaft 1122. An oil ring 115 is sleeved between the second part 11322 and the extension protrusion 1114. Rubber is vulcanized on the oil ring 115 to seal the gap between the second part 11322 and the extension protrusion 1114, so that the stator end plate and the housing 111 can define the following annular first chamber a and second chamber b, and can ensure the sealing effect of the first chamber a and the second chamber b.

[0050] like Figure 2 As shown, in some embodiments of the present invention, the stator end plate includes a first end plate 11323 and a second end plate 11324. The first end plate 11323 is disposed on the side of the stator 1131 facing the rear end plate, and the second end plate 11324 is disposed on the side of the stator 1131 facing the front end plate. A first chamber a is defined between the first end plate 11323 and the housing 111, and the first chamber a is located on the side of the first end plate 11323 near the rear end plate. A second chamber b is defined between the second end plate 11324 and the housing 111, and the second chamber b is located on the side of the second end plate 11324 near the front end plate. The first chamber a and the second chamber b communicate with each other. The body 1111 is provided with a medium inlet c and a medium outlet. The medium inlet c is used to allow the phase change medium to flow into the mounting cavity. The medium inlet c is opposite to and connected to the first chamber a. The medium outlet is opposite to and at least connected to the second chamber b. After the phase change medium enters through the medium inlet c, it can flow through the first chamber a and the second chamber b in sequence. During this process, the phase change medium can exchange heat with the stator assembly 113 to absorb the heat of the stator assembly 113, thereby achieving heat dissipation of the stator assembly 113. The phase change medium after absorbing heat can be discharged from the motor 110 through the medium outlet to ensure the heat exchange efficiency of the phase change medium to the motor 110.

[0051] Reference Figure 2In some embodiments of the present invention, a third chamber e is defined between the second end plate 11324, the housing 111, and the dynamic balance plate 1123 disposed on the same side as the second end plate 11324. Since the second part 11322 of the second end plate 11324 and the extended protrusion 1114 of the housing 111 can be sealed by an oil ring 115, the third chamber e can be spaced apart from the second chamber b, and the third chamber e is connected to the medium inlet c and the medium outlet respectively. The third chamber e can be connected to the medium inlet c through the first chamber a. In the flow direction of the phase change medium, since the second chamber b and the third chamber e are both located downstream of the first chamber a, and the second chamber b and the third chamber e are spaced apart, the medium outlet can be connected to the second chamber b and the third chamber e respectively, which facilitates the cooling medium passing through the second chamber b and the third chamber e to be discharged from the motor 110.

[0052] The phase change medium flowing into the motor 110 through the medium inlet c can flow into the third chamber e after passing through the first chamber a. During this process, the phase change medium can exchange heat with the rotor assembly 112 to absorb the heat of the stator and rotor assembly 112, thereby achieving heat dissipation of the rotor assembly 112. After absorbing heat, the phase change medium can be discharged from the motor 110 through the medium outlet from the third chamber e to ensure the heat exchange efficiency of the phase change medium to the motor 110.

[0053] Therefore, not only can heat dissipation be achieved for the stator assembly 113, but also for the rotor assembly 112, effectively improving the heat dissipation effect of the motor 110. At the same time, by separating the second chamber b and the third chamber e, the phase change medium can be diverted, improving the flow order of the phase change medium, which is conducive to improving the heat exchange efficiency. In addition, compared with immersing the stator assembly 113 and the rotor assembly 112 separately to dissipate heat from the stator assembly 113 and the rotor assembly 112, diverting the phase change medium to dissipate heat from the stator assembly 113 and the rotor assembly 112 separately can effectively reduce the amount of phase change medium used, which is conducive to reducing the mechanical loss of the motor 110.

[0054] Combination Figure 1 and Figure 2 In some embodiments of the present invention, the electric drive system 100 further includes a heat exchange assembly, which includes a condenser 151 and a radiator 152. The condenser 151 is a phase change heat exchanger that can liquefy the gaseous phase change medium and release latent heat, and the radiator 152 is a sensible heat heat exchanger that can cool the liquid medium and release sensible heat.

[0055] Since the second chamber b and the third chamber e are separated, the medium outlet needs to be connected to the second chamber b and the third chamber e respectively. Furthermore, considering that at least part of the liquid phase change medium will transform into a gaseous phase change medium after absorbing heat, and that the gaseous phase change medium has a lower density than the liquid phase change medium, the gaseous phase change medium in the second chamber b and the third chamber e will flow upward, while the liquid phase change medium will sink. Therefore, the medium outlets connected to the second chamber b and the third chamber e need to include outlets for discharging gaseous phase change medium and outlets for discharging liquid phase change medium respectively.

[0056] Based on this, the medium outlet of this application includes: a first liquid outlet d1, a first gas outlet d2, a second liquid outlet d3, and a second gas outlet d4. The first liquid outlet d1 is located at the bottom of the second chamber b, so that the liquid phase change medium in the second chamber b can be discharged from the second chamber b through the first liquid outlet d1. The first liquid outlet d1 is used to connect the second chamber b to the inlet end of the radiator 152, so that the liquid phase change medium discharged from the second chamber b can flow into the radiator 152 for cooling. The first gas outlet d2 is located at the top of the second chamber b, so that the gaseous phase change medium in the second chamber b can flow upward and be discharged from the second chamber b through the first gas outlet d2. The first gas outlet d2 is used to connect the second chamber b to the inlet end of the condenser 151. The gaseous phase change medium can flow into the condenser 151 to be converted into a liquid state; the second liquid outlet d3 is located at the bottom of the third chamber e so that the liquid phase change medium in the chamber can be discharged from the third chamber e through the second liquid outlet d3. The second liquid outlet d3 is used to connect the third chamber e to the inlet end of the radiator 152 so that the liquid phase change medium discharged from the third chamber e can flow into the radiator 152 for cooling; the second gas outlet d4 is located at the top of the third chamber e. The gaseous phase change medium in the third chamber e flows upward and can be discharged from the third chamber e through the second gas outlet d4. The second gas outlet d4 is used to connect the third chamber e to the inlet end of the radiator 152. The gaseous phase change medium can flow into the condenser 151 to be converted into a liquid state.

[0057] The outlet end of the condenser 151 is connected to the inlet end of the radiator 152 so that the phase change medium converted into liquid in the condenser 151 can flow into the radiator 152 for further heat dissipation, thereby improving the heat absorption capacity of the phase change medium. The outlet end of the radiator 152 is connected to the medium inlet c so that the phase change medium after heat dissipation can flow back into the motor 110 for the next heat exchange cycle.

[0058] Combination Figure 2 and Figure 3In some embodiments of the present invention, a baffle 160 is provided on the side of the conductive coil 121 facing the spline shaft 2. The baffle 160 is used to separate the conductive coil 121 from the spline shaft 2 and define a first heat exchange cavity f that communicates with the first chamber a. The phase change medium can flow from the first chamber a into the first heat exchange cavity f and exchange heat with the conductive coil 121 to absorb the heat generated when the conductive coil 121 is working, which is beneficial to improving the service life of the conductive coil 121. Due to the setting of the baffle 160, the first heat exchange cavity f can be effectively isolated from the spline shaft 2 to prevent the phase change medium in the first heat exchange cavity f from leaking on the spline shaft 2 side.

[0059] The magnetic conductive element 122 and the bearing 114 are spaced apart so that a second heat exchange cavity g is formed between the magnetic conductive element 122, the bearing 114 and the rotating shaft 1122. The second heat exchange cavity g is connected to the first heat exchange cavity f and the third cavity e, respectively. For ease of explanation, the magnetic conductor 122, bearing 114, and rotating shaft 1122 located on one side of the rear end cover 1113 are used as examples. The magnetic conductor 122, which is positioned opposite to the bearing 114, is spaced apart from the bearing 114 in a direction parallel to the rotating shaft 1122. The bearing 114 is sleeved on one end of the rotor shaft 1. The intermediate shaft 3 is located between the spline shaft 2 and the rotor shaft 1 and is spaced apart from the rotor shaft 1, so that the magnetic conductor 122, bearing 114, rotor shaft 1, and intermediate shaft 3 together define a second heat exchange cavity g. The second heat exchange cavity g connects the first heat exchange cavity f and the third cavity e. The phase change medium flowing through the first heat exchange cavity f can further flow into the second heat exchange cavity g, and after passing through the rotor assembly 112, it flows into the third cavity e, thereby achieving heat dissipation for the magnetic conductor coil and the rotor assembly 112 respectively, improving the heat dissipation efficiency of the motor 110, and thus helping to improve the operational reliability of the motor 110.

[0060] Combination Figure 2 and Figure 3In some embodiments of the present invention, the motor 110 is provided with a heat exchange channel, which includes a first channel section, a second channel section h2, a third channel section, and a fourth channel section h4. The first channel section is disposed through the stator assembly 113 in a direction parallel to the axial direction of the stator assembly 113 to connect the first chamber a and the second chamber b. The phase change medium flowing into the first chamber a through the medium inlet c can flow through the first channel section through the stator assembly 113. During the process of the phase change medium flowing through the stator assembly 113, it can absorb heat. The heat generated by the stator assembly 113 is absorbed to dissipate heat from the stator assembly 113. The phase change medium after heat exchange with the stator assembly 113 flows further into the second chamber b through the first flow channel section. During this process, since the phase change medium absorbs the heat from the stator assembly 113, a portion of the phase change medium will be converted into a gaseous state. The gaseous phase change medium flows upward and is discharged from the motor 110 through the first gas outlet d2, while the remaining portion of the phase change medium sinks and can be discharged from the motor 110 through the first liquid outlet d1.

[0061] The second flow channel section h2 is located inside the rear end plate, and one end of the second flow channel section h2 is connected to the first chamber a. The other end of the second flow channel section h2 is connected to the first heat exchange chamber f and the second heat exchange chamber g respectively. The third flow channel section is located on the magnetic guide 122 near the bearing 114, and the third flow channel section is arranged through the magnetic guide 122 in an axial direction parallel to the rotating shaft 1122. The third flow channel section is used to connect the first heat exchange chamber f and the second heat exchange chamber g. The fourth flow channel section h4 is located on the rotor assembly 112 and extends bent on the rotor assembly 112. The fourth flow channel section h4 is used to connect the second heat exchange chamber g and the third chamber e.

[0062] In other words, the phase change medium entering the first chamber a can be split. One part of the phase change medium flows through the first flow channel section to the stator assembly 113 to exchange heat with the stator assembly 113, while the other part of the phase change medium can flow into the first heat exchange chamber f and the second heat exchange chamber g through the second flow channel section h2. The phase change medium entering the first heat exchange chamber f can absorb the heat generated when the conductive coil 121 is working. After absorbing heat in the first heat exchange chamber f, the phase change medium can further flow into the second heat exchange chamber g through the third flow channel section provided on the magnetic conductive element 122. The phase change medium entering the second heat exchange chamber g through the second flow channel section h2 and the phase change medium flowing into the second heat exchange chamber g through the third flow channel section are combined. The phase change medium inside can converge and then flow through the fourth flow channel section h4 provided on the rotor assembly 112. The phase change medium can absorb the heat generated by the rotor assembly 112 to dissipate heat from the rotor assembly 112. After absorbing heat, the phase change medium further flows into the third chamber e through the fourth flow channel section h4. During this process, because the phase change medium absorbs the heat of the rotor assembly 112, a portion of the phase change medium will be converted into a gaseous state. The gaseous phase change medium flows upward and is discharged from the motor 110 through the second gas outlet d4, while the remaining portion of the phase change medium sinks and can be discharged from the motor 110 through the second liquid outlet d3.

[0063] The gaseous phase change medium flowing out from the first gas outlet d2 and the second gas outlet d4 flows into the condenser 151 and is converted into a liquid state. The liquid phase change medium flowing out from the first liquid outlet d1, the second liquid outlet d3 and the condenser 151 flows into the radiator 152 for further heat dissipation. The phase change medium after heat dissipation flows back to the medium inlet c to facilitate the next heat exchange cycle.

[0064] The cross-sectional area of ​​the fourth flow channel section h4 is at least smaller than that of the second flow channel section h2. The pressure of the phase change medium decreases when it flows through the fourth flow channel section h4, thereby lowering its boiling point. Furthermore, due to the bend and extension of the fourth flow channel section h4, the flow path of the phase change medium through the fourth flow channel section h4 is longer, allowing the phase change medium to fully exchange heat with the rotor assembly 112 when it flows through the fourth flow channel section h4. This is beneficial to improving the conversion of the liquid phase change medium into a gaseous state. In addition, the phase change medium can absorb a large amount of latent heat during the vaporization process, thereby improving the heat dissipation effect of the rotor assembly 112.

[0065] In some specific embodiments, the fourth flow channel section h4 includes a first sub-segment, a second sub-segment, and a third sub-segment. The first sub-segment can be formed by the radial gap between the rotor shaft 1 and the intermediate shaft 3. The second sub-segment can pass through the rotor shaft 1 along the axial direction of the rotor assembly 112 and extend into the dynamic balance plate 1123. The third sub-segment extends in a direction parallel to the axial direction of the rotor assembly 112, and the third sub-segment connects to the end of the second sub-segment located in the dynamic balance plate 1123 away from the rotor shaft 1, and passes through the rotor 1121 and the dynamic balance plate 1123 located adjacent to the third chamber e. Thus, a bent and extended fourth flow channel section h4 is formed. The phase change medium can flow through the fourth flow channel section h4 not only through the rotor shaft 1122, but also through the rotor 1121 and the dynamic balance plate 1123, effectively improving the heat dissipation efficiency of the phase change medium on the rotor assembly 112.

[0066] like Figure 1 As shown, in some embodiments of the present invention, a switching valve 170 is provided at the first liquid outlet d1. The switching valve 170 is adapted to open when the temperature of the phase change medium reaches a preset temperature. The preset temperature is greater than the critical temperature at which the phase change medium undergoes a phase change, so as to prevent the phase change medium entering the motor 110 from flowing out directly through the first liquid outlet d1 before reaching the phase change temperature. This ensures that the phase change medium can immerse at least part of the components arranged in the mounting cavity, and also ensures that the phase change working medium can fully absorb heat, thereby improving the heat exchange effect of the motor 110 and improving the energy utilization rate of the phase change working medium.

[0067] The vehicle according to an embodiment of the present invention includes the electric drive system 100 described above.

[0068] Because the vehicle is equipped with the aforementioned electric drive system 100, the reliability of vehicle operation and its service life can be effectively guaranteed.

[0069] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0070] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An electric drive system, characterized in that, include: The motor (110) includes a housing (111) with an internally formed mounting cavity, the mounting cavity having at least a moving part and being adapted to contain a phase change medium for at least cooling the moving part, the phase change medium being capable of converting between gas and liquid phases under the influence of heat; A magnetic fluid sealing device (120) is disposed between the moving part and the housing (111) to prevent leakage of the phase change medium.

2. The electric drive system according to claim 1, characterized in that, The motor (110) also includes: A stator assembly (113) is fixedly installed inside the housing (111), and the stator assembly (113) includes a stator (1131) and a stator end plate. The stator (1131) has stator end plates at both axial ends, and the stator end plates are used to limit the stator (1131). The moving component includes: a rotor assembly (112), which is disposed within the stator assembly (113). The rotor assembly (112) is rotatable relative to the stator assembly (113). The rotor assembly (112) includes a rotor (1121), a rotating shaft (1122), and dynamic balance plates (1123) disposed at both axial ends of the rotor (1121). The rotating shaft (1122) is disposed through the rotor (1121) along the axial direction of the rotor (1121), and at least a portion of the rotating shaft (1122) extends out from the housing (111). The magnetohydrodynamic sealing device (120) is disposed between the rotating shaft (1122) and the housing (111).

3. The electric drive system according to claim 2, characterized in that, The housing (111) includes: a housing body (1111), a front end cover (1112), and a rear end cover (1113). The front end cover (1112) and the rear end cover (1113) are respectively disposed on both axial sides of the housing body (1111), and the magnetohydrodynamic sealing device (120) is respectively provided between the front end cover (1112) and the rotating shaft (1122) and between the rear end cover (1113) and the rotating shaft (1122).

4. The electric drive system according to claim 3, characterized in that, The magnetic fluid sealing device (120) includes: A conductive coil (121) that generates a magnetic field when energized is located in the radial direction of the rotating shaft (1122). The conductive coil (121) is disposed between the housing (111) and the rotating shaft (1122), and is spaced apart from the rotating shaft (1122) and the housing (111), respectively. The magnetic conductor (122) is disposed on both sides of the conductive coil (121) in an axial direction parallel to the rotating shaft (1122), and the side of the magnetic conductor (122) facing the housing (111) is adapted to be sealed with the housing (111). A magnetic fluid is disposed between the rotating shaft (1122) and the magnetic conductor (122).

5. The electric drive system according to claim 4, characterized in that, The rotating shaft (1122) has a toothed groove on the side facing the housing (111), the magnetic conductive element (122) has a tooth tip adapted to engage with the toothed groove, and the magnetic fluid is disposed within the toothed groove. The rotating shaft (1122) includes: Rotor shaft (1), the rotor shaft (1) is connected to the rotor (1121), and the two ends of the rotor shaft (1) are respectively mounted on the front end cover (1112) and the rear end cover (1113) through bearings (114). One end of the rotor shaft (1) extends out from the front end cover (1112), and the toothed groove is provided on the side facing the front end cover (1112). Spline shaft (2), the spline shaft (2) is located inside the rotor shaft (1), and the two ends of the spline shaft (2) extend from the front end cover (1112) and the rear end cover (1113) respectively. The spline shaft (2) has the toothed groove on the side facing the rear end cover (1113). Intermediate shaft (3), the intermediate shaft (3) is located between the rotor shaft (1) and the spline shaft (2), and in the axial direction parallel to the rotating shaft (1122), at least a portion of the end of the intermediate shaft (3) facing the rear end cover (1113) is located between the spline shaft (2) and the rotor shaft (1), and is spaced apart from the rotor shaft (1).

6. The electric drive system according to claim 5, characterized in that, The stator end plate includes: The first part (11321) is disposed opposite to the stator (1131) in an axial direction parallel to the stator (1131) and is used to limit the stator (1131); The second part (11322) is connected to the radial inner end of the first part (11321) and extends toward the housing (111) in an axial direction parallel to the stator (1131). The housing (111) has an extension protrusion (1114) which is disposed opposite to the second part (11322). An oil ring (115) is provided between the extension protrusion (1114) and the second part (11322) for sealing the second part (11322) and the extension protrusion (1114).

7. The electric drive system according to claim 6, characterized in that, The stator end plate includes a first end plate (11323) and a second end plate (11324). The first end plate (11323) is disposed on the side of the stator (1131) facing the rear end plate, and the second end plate (11324) is disposed on the side of the stator (1131) facing the front end plate. A first chamber (a) is defined between the first end plate (11323) and the housing (111). The first chamber (a) is located on the side of the first end plate (11323) near the rear end plate. A second chamber (b) is defined between the second end plate (11324) and the housing (111). The second chamber (b) is located on the side of the second end plate (11324) near the front end plate. The first chamber (a) and the second chamber (b) communicate with each other. The shell body (1111) is provided with a medium inlet (c) and a medium outlet. The medium inlet (c) is used to allow the phase change medium to flow into the mounting cavity. The medium inlet (c) is opposite to and communicates with the first chamber (a). The medium outlet is opposite to and at least communicates with the second chamber (b).

8. The electric drive system according to claim 7, characterized in that, A third chamber (e) is defined between the second end plate (11324), the housing (111), and the dynamic balance plate (1123) disposed on the same side as the second end plate (11324). The third chamber (e) is spaced apart from the second chamber (b), and the third chamber (e) is connected to the medium inlet (c) and the medium outlet, respectively.

9. The electric drive system according to claim 8, characterized in that, Also includes: The heat exchange assembly includes a condenser (151) and a radiator (152), and the medium outlet includes: The first liquid outlet (d1) is located at the bottom of the second chamber (b) and is used to connect the second chamber (b) to the inlet end of the radiator (152); A first gas outlet (d2) is located at the top of the second chamber (b) and is used to connect the second chamber (b) to the inlet end of the condenser (151); The second liquid outlet (d3) is located at the bottom of the third chamber (e) and is used to connect the third chamber (e) to the inlet end of the radiator (152); The second gas outlet (d4) is located at the top of the third chamber (e) and is used to connect the third chamber (e) to the inlet end of the radiator (152); The outlet end of the condenser (151) is connected to the inlet end of the radiator (152), and the outlet end of the radiator (152) is connected to the medium inlet (c).

10. The electric drive system according to claim 9, characterized in that, A baffle (160) is provided on the side of the conductive coil (121) facing the spline shaft (2). The baffle (160) is used to space the conductive coil (121) from the spline shaft (2) and define a first heat exchange chamber (f) that communicates with the first chamber (a). The magnetic conductor (122) is spaced apart from the bearing (114) so ​​that a second heat exchange chamber (g) is formed between the magnetic conductor (122), the bearing (114) and the rotating shaft (1122), and the second heat exchange chamber (g) is connected to the first heat exchange chamber (f) and the third chamber (e) respectively.

11. The electric drive system according to claim 10, characterized in that, The motor (110) is provided with a heat exchange channel, the heat exchange channel including: A first flow channel section is provided through the stator assembly (113) in an axial direction parallel to the stator assembly (113) to connect the first chamber (a) and the second chamber (b). The second flow channel section (h2) is located inside the rear end plate, and one end of the second flow channel section (h2) is connected to the first chamber (a), and the other end of the second flow channel section (h2) is connected to the first heat exchange chamber (f) and the second heat exchange chamber (g) respectively. The third flow channel section is disposed on the magnetic guide (122) near the bearing (114), and the third flow channel section is disposed through the magnetic guide (122) in an axial direction parallel to the rotating shaft (1122). The third flow channel section is used to connect the first heat exchange chamber (f) and the second heat exchange chamber (g). The fourth flow channel section (h4) is disposed on the rotor assembly (112) and extends by bending on the rotor assembly (112), and the fourth flow channel section (h4) is used to connect the second heat exchange chamber (g) and the third chamber (e); The flow cross-sectional area of ​​the fourth flow channel section (h4) is at least smaller than the flow cross-sectional area of ​​the second flow channel section (h2).

12. The electric drive system according to claim 9, characterized in that, A switching valve (170) is provided at the first liquid outlet (d1). The switching valve (170) is adapted to open when the temperature of the phase change medium reaches a preset temperature, which is greater than the critical temperature at which the phase change medium undergoes a phase change.

13. A vehicle, characterized in that, Includes the electric drive system according to any one of claims 1-12.

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