Electric drive system and vehicle with same

Abstract

The present invention relates to an electric drive system and a vehicle with same. The electric drive system comprises: a stator; a rotor, which matches the stator; a speed reducer, which is connected to the rotor; and an oil passage mechanism, which comprises a main oil passage configured to convey a cooling liquid; and a stator side branch oil passage, a rotor side branch oil passage and a speed reducer side branch oil passage which are respectively in communication with the main oil passage so as to convey the cooling liquid to the stator, the rotor and the speed reducer at the same time. In the vehicle disclosed in the present invention, the stator, the rotor and the speed reducer of the electric drive system can be cooled at the same time, so that the overall cooling requirement of the electric drive system can be met properly.

Description

Electric drive system and vehicle having the same

[0001] Priority claim

[0002] This application claims priority to Chinese patent application CN202323368899.6, filed on December 8, 2023, with the invention name “Electric drive system and vehicle having the same”. The entire contents of the above Chinese patent application are incorporated into this application by reference. Technical Field

[0003] The present invention relates to the technical field of vehicles, and in particular to an electric drive system and a vehicle having the same. Background Art

[0004] The Electric Drive System (EDS) consists of components such as the electric motor, motor controller, and transmission mechanism. Its primary function is to convert electrical energy into mechanical energy to propel the vehicle. Because the EDS uses an electric motor as its power source, it achieves higher energy efficiency and reduces energy waste. Furthermore, the EDS utilizes electronic control technology, enabling precise control and improving vehicle efficiency and safety.

[0005] With the rapid development of new energy vehicles, the power density of electric drive systems continues to increase, placing increasing demands on their cooling. Water cooling of transmissions is no longer sufficient for current electric drive system cooling needs, and it is even more difficult to directly cool the stators and rotors in electric motors, which require high insulation. Consequently, an increasing number of automakers are turning to oil cooling for their electric drive systems.

[0006] However, most of the oil cooling methods in the existing technology can only serve as refrigerants for the rotor and stator of the electric motor, and cannot cool the rotor, stator and reducer at the same time. It is difficult to meet the overall cooling needs of the electric drive system, which greatly affects the performance and service life of the electric drive system.

[0007] Therefore, this field needs a new technical solution to solve the above problems.

[0008] Summary of the Invention

[0009] To address or, to a certain extent, improve the technical problem that oil cooling methods in the prior art cannot meet the overall cooling needs of an electric drive system, the present invention provides an electric drive system. The electric drive system comprises: a stator; a rotor mated with the stator; a reducer connected to the rotor; and an oil circuit mechanism, the oil circuit mechanism comprising a main oil circuit for conveying coolant, and stator-side branch oil circuits, rotor-side branch oil circuits, and reducer-side branch oil circuits, each connected to the main oil circuit, to simultaneously convey coolant to the stator, rotor, and reducer.

[0010] It will be understood by those skilled in the art that the electric drive system of the present invention includes a stator, a rotor, a reducer and an oil circuit mechanism. Among them, the rotor and the stator match, and the reducer is connected to the rotor. The oil circuit mechanism includes a main oil circuit, a stator side branch oil circuit, a rotor side branch oil circuit and a reducer side branch oil circuit. The main oil circuit is used to transport coolant, and the stator side branch oil circuit, the rotor side branch oil circuit and the reducer side branch oil circuit are respectively connected to the main oil circuit, so that the coolant in the main oil circuit can be simultaneously guided to the stator, rotor and reducer along the stator side branch oil circuit, the rotor side branch oil circuit and the reducer side branch oil circuit. Through the above-mentioned arrangement, the electric drive system of the present invention can guide the coolant to the stator, rotor and reducer at the same time, meeting the overall cooling needs of the electric drive system.

[0011] In a preferred technical solution of the above-mentioned electric drive system, the main oil circuit is provided with spaced-apart stator-side oil inlet holes, rotor-side oil inlet holes, and reducer-side oil inlet holes. The stator-side oil inlet holes communicate with the stator-side branch oil circuit, the rotor-side oil inlet holes communicate with the rotor-side branch oil circuit, and the reducer-side oil inlet holes communicate with the reducer-side branch oil circuit. The spaced-apart stator-side, rotor-side, and reducer-side oil inlet holes facilitate the routing of coolant from the main oil circuit to the stator-side, rotor-side, and reducer-side branch oil circuits.

[0012] In the preferred technical solution of the above-mentioned electric drive system, the stator includes a stator core, a stator core oil inlet disposed in the middle of the stator core and connected to the stator-side oil distribution path, and stator core oil outlets disposed at the left and right ends of the stator core. The stator core oil outlets are connected to the stator core oil inlet via stator core oil guide channels. This arrangement allows coolant to flow throughout the stator core, improving cooling distribution uniformity.

[0013] In the preferred technical solution of the above electric drive system, the stator core oil inlet is arranged at the top of the stator core. Through the above arrangement, the coolant entering the stator core oil inlet can flow quickly under the action of its own gravity, thereby improving cooling efficiency.

[0014] In a preferred technical solution for the aforementioned electric drive system, the stator core is formed by stacking multiple silicon steel sheets in sequence, with adjacent sheets arranged in a staggered pattern. Each sheet is provided with oil holes spaced apart from one another, so that the oil holes on all sheets together form a stator core oil channel arranged spirally about the central axis of the stator core. This arrangement allows the stator core oil channel to be evenly arranged spirally along the central axis of the stator core, further improving the uniformity of coolant distribution.

[0015] In the preferred technical solution of the above-mentioned electric drive system, an oil retaining ring is provided at each end of the stator core, and a plurality of oil drain holes spaced apart from each other are provided on each oil retaining ring, so that the coolant flowing out of the oil outlet of the stator core can be discharged through the oil drain holes. The provision of the oil retaining ring can prevent excessive or insufficient coolant in the stator core, thereby providing isolation and sealing. In addition, the coolant dripping from the oil retaining ring can also cool the stator windings at both ends.

[0016] In the preferred technical solution of the above-mentioned electric drive system, the rotor includes: a rotor shaft, on which is provided a central cavity connected to the rotor-side oil distribution circuit and a plurality of spaced-apart oil-swing holes, each of which is connected to the central cavity; and a rotor core, which surrounds the rotor shaft, with a plurality of oil guide grooves spaced between the rotor core and the rotor shaft, each of which is connected to a corresponding oil-swing hole. This arrangement allows coolant in the rotor-side oil distribution circuit to sequentially pass through the central cavity, the oil-swing holes, and the oil guide grooves, thereby cooling the rotor shaft and rotor core.

[0017] In the preferred technical solution of the electric drive system, the plurality of oil-slinging holes are evenly spaced along the circumference of the rotor shaft. This arrangement can improve the uniformity of the coolant flowing out of the central cavity.

[0018] In a preferred technical solution of the above-mentioned electric drive system, the rotor core is provided with a plurality of spaced-apart rotor core oil guide channels; a dynamic balancing plate is provided at each end of the rotor core, and each dynamic balancing plate is provided with a spaced-apart dynamic balancing plate oil inlet hole and a dynamic balancing plate oil outlet hole. Each dynamic balancing plate oil inlet hole and dynamic balancing plate oil outlet hole are connected to a corresponding oil guide groove, and the dynamic balancing plate oil inlet hole on each dynamic balancing plate is connected to the dynamic balancing plate oil outlet hole on another dynamic balancing plate through the corresponding rotor core oil guide channel. This arrangement allows coolant to flow evenly within the rotor core oil guide channels between the dynamic balancing plate oil inlet hole and the dynamic balancing plate oil outlet hole, thereby improving the cooling effect on the rotor core.

[0019] In a preferred embodiment of the electric drive system, each dynamic balancing plate is provided with a first L-shaped oil guide structure. The first L-shaped oil guide structure comprises a first radial segment and a first circumferential segment connected to each other. The first radial segment is connected to the oil guide groove, and the dynamic balancing plate oil inlet is provided on the first circumferential segment. The provision of the first L-shaped oil guide structure facilitates communication between the oil guide groove and the rotor core oil guide channel.

[0020] In a preferred embodiment of the electric drive system, each dynamic balancing plate is provided with a second L-shaped oil guide structure, spaced apart from the first L-shaped oil guide structure. The second L-shaped oil guide structure comprises a second radial segment and a second circumferential segment connected to each other, with the oil outlet opening of the dynamic balancing plate being provided in the second circumferential segment. The provision of the second L-shaped oil guide structure facilitates the discharge of coolant from the rotor core through the dynamic balancing plates at both ends.

[0021] In the preferred technical solution of the above electric drive system, each rotor core oil guide channel is arranged spirally around the central axis of the rotor shaft. The spiral arrangement of the rotor core oil guide channel can extend the oil path and improve the cooling effect of the coolant on the rotor core.

[0022] In a preferred embodiment of the electric drive system, the electric drive system further includes a liquid distribution pipe connected to the reducer-side oil distribution circuit. The liquid distribution pipe has multiple, spaced-apart branches, and at least some of the branches can direct the coolant to the reducer. The provision of the liquid distribution pipe facilitates directing the coolant in the reducer-side oil distribution circuit to appropriate locations on the reducer, thereby providing cooling and lubrication for these locations.

[0023] In a preferred embodiment of the electric drive system, the reducer includes an intermediate shaft meshing with the rotor's input gear, the intermediate shaft having a first intermediate shaft bearing and a second intermediate shaft bearing for supporting the intermediate shaft. Furthermore, the multiple branch pipes include a first branch pipe mating with the first intermediate shaft bearing, a second branch pipe mating with the second intermediate shaft bearing, and a third branch pipe mating with the meshing portion between the intermediate shaft and the input gear. This arrangement facilitates cooling and lubrication of the intermediate shaft bearings (i.e., the first and second intermediate shaft bearings) and the meshing portion between the intermediate shaft and the input gear.

[0024] In the preferred technical solution of the above electric drive system, the rotor has a first rotor bearing close to the reducer, a second rotor bearing farther from the reducer, and a third rotor bearing located between the first and second rotor bearings. Furthermore, the multiple branch pipes further include a fourth branch pipe corresponding to the first rotor bearing and a fifth branch pipe corresponding to the third rotor bearing. With this arrangement, the liquid distribution pipe can also direct some of the coolant in the oil distribution circuit on the reducer side to the first and third rotor bearings.

[0025] In a preferred embodiment of the electric drive system, the oil circuit mechanism further includes a rotor bearing oil circuit, which communicates with the stator-side oil circuit to direct a portion of the coolant within the stator-side oil circuit to the second rotor bearing. This arrangement facilitates directing a portion of the coolant within the stator-side oil circuit to the second rotor bearing for cooling and lubrication, thereby improving oil circuit utilization.

[0026] In the preferred technical solution of the above-mentioned electric drive system, the electric drive system also includes a casing, and the stator, the rotor, and the reducer are all arranged in the casing, and the stator-side oil branch circuit, the rotor-side oil branch circuit, and the reducer-side oil branch circuit are all integrally formed with the casing. The setting of the casing can provide suitable installation space for the stator, rotor, and reducer. In addition, the stator-side oil branch circuit, the rotor-side oil branch circuit, and the reducer-side oil branch circuit are all integrally formed with the casing, which can simplify the component structure, facilitate processing and manufacturing, and ensure the sealing performance of the oil circuit.

[0027] To address or, to a certain extent, improve the technical problem in existing oil cooling methods that cannot meet the overall cooling requirements of an electric drive system, the present invention provides a vehicle. The vehicle includes any of the above-described electric drive systems. By employing any of the above-described electric drive systems, the vehicle of the present invention can simultaneously cool the stator, rotor, and reducer of the electric drive system, effectively meeting the overall cooling requirements of the electric drive system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0029] FIG1 is a schematic structural diagram of an embodiment of an electric drive system of the present invention;

[0030] FIG2 is a first cross-sectional schematic diagram of an embodiment of the electric drive system of the present invention;

[0031] FIG3 is a schematic structural diagram of an embodiment of a stator of an electric drive system of the present invention;

[0032] FIG4 is a schematic structural diagram of an embodiment of a silicon steel sheet of a stator of an electric drive system according to the present invention;

[0033] FIG5 is a schematic structural diagram of an embodiment of an oil slinger ring of an electric drive system of the present invention;

[0034] FIG6 is a second cross-sectional schematic diagram of an embodiment of the electric drive system of the present invention;

[0035] FIG7 is a schematic structural diagram of an embodiment of a rotor of an electric drive system of the present invention;

[0036] FIG8 is a cross-sectional schematic diagram of an embodiment of a rotor core of an electric drive system of the present invention;

[0037] FIG9 is a schematic structural diagram of an embodiment of a dynamic balancing plate of an electric drive system of the present invention;

[0038] FIG10 is a third cross-sectional schematic diagram of an embodiment of the electric drive system of the present invention;

[0039] FIG11 is a schematic structural diagram of an embodiment of a housing and a liquid dispensing pipe of an electric drive system of the present invention.

[0040] Reference numerals: 1. electric drive system; 10. housing; 11. oil sump; 20. oil pump; 30. oil filter; 40. Heat exchanger; 50. Stator; 51. Stator core; 511. Stator core oil inlet; 512. Stator core oil outlet; 513. Stator core oil guide channel; 514. Silicon steel sheet; 5141. Oil hole; 52. Stator winding; 60. Oil retaining ring; 61. Oil drain hole; 70. Rotor; 71. Rotor shaft; 711. Central cavity; 712. Oil throwing hole; 713. Input gear; 72. Rotor core; 721. Rotor core oil guide channel; 73. Oil guide groove; 74. Rotor first bearing; 75. Rotor second bearing; 76. Rotor third bearing; 80. Dynamic balancing plate; 81. First L-shaped oil guide structure; 811. First radial section; 812. First circumferential section; 813. Dynamic balancing plate oil inlet; 82. Two L-shaped oil guide structures; 821, second circumferential section; 822, second radial section; 823, dynamic balancing plate oil outlet hole; 83, dynamic balancing plate auxiliary oil outlet hole; 90, reducer; 91, intermediate shaft; 911, first gear; 912, second gear; 92, output gear; 100, oil circuit mechanism; 110, main oil circuit; 111, stator side oil inlet hole; 112, rotor side oil inlet hole; 113, reducer side oil inlet hole; 120, stator side oil branch circuit; 130, rotor side oil branch circuit; 140, reducer side oil branch circuit; 150, rotor bearing oil branch circuit; 160, flow limiter; 170, liquid distribution pipe; 171, first branch pipe; 172, second branch pipe; 173, third branch pipe; 174, fourth branch pipe; 175, fifth branch pipe. DETAILED DESCRIPTION

[0041] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0042] It should be noted that in the description of the present invention, terms such as "upper," "lower," "left," "right," "front," "back," "inner," and "outer" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. These are merely for ease of description and are not intended to indicate or imply that the device or component described must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "installed," "disposed," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0044] To solve or, to a certain extent, improve the technical problem that oil cooling methods in the prior art cannot meet the overall cooling requirements of an electric drive system, the present invention provides an electric drive system 1. The electric drive system 1 includes: a stator 50; a rotor 70, which is matched with the stator 50; a reducer 90, which is connected to the rotor 70; and an oil circuit mechanism 100. The oil circuit mechanism 100 includes a main oil circuit 110 for conveying coolant, and a stator-side branch oil circuit 120, a rotor-side branch oil circuit 130, and a reducer-side branch oil circuit 140, which are respectively connected to the main oil circuit 110, so as to simultaneously convey coolant to the stator 50, the rotor 70, and the reducer 90.

[0045] Figure 1 is a schematic structural diagram of an embodiment of an electric drive system according to the present invention; Figure 2 is a first cross-sectional schematic diagram of an embodiment of the electric drive system according to the present invention. As shown in Figures 1 and 2, in one or more embodiments, the electric drive system 1 according to the present invention includes components such as a housing 10, an oil pump 20, a heat exchanger 40, a stator 50, a rotor 70, a reducer 90, and an oil circuit mechanism 100. The housing 10 can be made of a suitable metal material, such as cast iron, stainless steel, or aluminum alloy, to provide good mechanical strength. The housing 10 provides suitable installation space for components such as the oil pump 20, the heat exchanger 40, the stator 50, the rotor 70, the reducer 90, and the oil circuit mechanism 100, thereby ensuring the structural stability of the entire electric drive system 1. An oil pool 11 for storing coolant is formed at the bottom of the housing 10. The oil pump 20 is connected to the oil pool 11 to pump the coolant within the oil pool 11. In one or more embodiments, the electric drive system 1 also includes a resolver sensor (not shown) for detecting the position signal of the rotor 70 and a temperature sensor (not shown) for detecting the real-time oil temperature of the coolant. The oil pump 20 is configured to adjust the flow rate of the coolant based on the data fed back by the rotary sensor and the temperature sensor. The oil circuit mechanism 100 includes a main oil circuit 110. The main oil circuit 110 is connected to the oil pump 20 to transport the coolant. The main oil circuit 110 is connected to the heat exchanger 40 to reduce the temperature of the coolant in the main oil circuit 110. In one or more embodiments, an oil filter 30 is further provided downstream of the oil pump 20 to filter impurities in the coolant. Alternatively, the arrangement position of the oil filter 30 can also be adjusted according to actual needs, for example, it can be arranged upstream of the oil pump 20.

[0046] Continuing with Figure 2 , the stator 50 is fixed within the housing 10, and the rotor 70 is rotatably fixed within the housing 10 and mated with the stator 50, so that when the magnetic field of the stator 50 changes, the rotor 70 is driven to rotate, thereby converting electrical energy into mechanical energy. The reducer 90 is connected to the rotor 70 to adjust the output speed. Continuing with Figure 1 , the main oil circuit 110 is provided with a stator-side oil inlet 111, a rotor-side oil inlet 112, and a reducer-side oil inlet 113, which are spaced apart from each other. The oil circuit mechanism 100 also includes a stator-side branch oil circuit 120, a rotor-side branch oil circuit 130, and a reducer-side branch oil circuit 140 (see Figures 2 and 10 ). The stator-side oil inlet 111 is connected to the stator-side oil branch 120, the rotor-side oil inlet 112 is connected to the rotor-side oil branch 130, and the reducer-side oil inlet 113 is connected to the reducer-side oil branch 140, thereby simultaneously supplying coolant to the stator 50, the rotor 70, and the reducer 90. In one or more embodiments, the stator-side oil branch 120, the rotor-side oil branch 130, and the reducer-side oil branch 140 are integrally formed with the housing 10 to simplify the component structure, facilitate processing and manufacturing, and ensure the sealing performance of the oil circuits.

[0047] Figure 3 is a schematic structural diagram of an embodiment of the stator of an electric drive system according to the present invention. As shown in Figures 2 and 3, in one or more embodiments, the stator 50 includes a stator core 51 and stator windings 52 wound around the stator core 51. Referring to Figure 2 and based on the orientation shown in Figure 2, the inner wall of the upper housing 10 and the circumferential outer wall of the stator core 51 together form a stator-side oil distribution path 120. Continuing with Figure 3, in one or more embodiments, three stator core oil inlets 511 are spaced apart from each other in the central portion of the stator core 51. Each stator core oil inlet 511 is connected to the stator-side oil distribution path 120. Alternatively, the number of stator core oil inlets 511 may be set to any other suitable number, such as two or four, or more. In one or more embodiments, the stator core oil inlets 511 are located at the top of the stator core 51, allowing the coolant to flow rapidly under its own gravity. In one or more embodiments, three stator core oil outlets 512 are provided at the left and right ends of the stator core 51, respectively, spaced apart from each other. Alternatively, the stator core oil outlets 512 may be provided at a suitable number greater or less than three, such as two or four. The stator core oil inlet 511 and the stator core oil outlet 512 are connected by a stator core oil guide channel 513, so that coolant flowing into the stator core oil inlet 511 flows along the stator core oil guide channel 513 and out of the stator core oil outlet 512.

[0048] As shown in FIG3 , in one or more embodiments, the stator core 51 is formed by stacking a plurality of silicon steel sheets 514 in sequence. FIG4 is a schematic structural diagram of an embodiment of the silicon steel sheets of the stator of the electric drive system of the present invention. As shown in FIG4 , in one or more embodiments, three oil holes 5141 spaced apart from each other are provided on each silicon steel sheet 514. Alternatively, the number of oil holes 5141 can also be set to other suitable numbers that are more or less than three. Continuing to refer to FIG3 , adjacent silicon steel sheets 514 are arranged in a staggered manner so that the oil holes 5141 on all silicon steel sheets 514 together form a stator core oil guide channel 513 that is spirally arranged around the central axis of the stator core 51. It can be understood that the oil holes 5141 on the silicon steel sheets 514 at the left and right ends are the stator core oil outlets 512 of the entire stator core 51. In addition, one or more silicon steel sheets 514 located in the middle of the stator core 51 are provided with notches that communicate with the stator-side oil distribution passage 120, thereby forming a stator core oil inlet 511. This arrangement allows the stator core oil guide channels 513 to be evenly arranged in a spiral along the central axis of the stator core 51, further improving the uniformity of coolant distribution.

[0049] As shown in Figure 2, in one or more embodiments, an oil retaining ring 60 is provided at the left and right ends of the stator core 51. The oil retaining ring 60 is fixed on the casing 10. Figure 5 is a structural schematic diagram of an embodiment of the oil retaining ring of the electric drive system of the present invention. As shown in Figure 5, in one or more embodiments, a plurality of oil drain holes 61 spaced apart from each other are provided on the oil retaining ring 60. The provision of the oil retaining ring 60 can prevent excessive or insufficient coolant in the stator core 51, and play an isolation and sealing role. The provision of the oil drain hole 61 can allow the coolant flowing out of the stator core oil outlet 512 to be smoothly discharged from the oil drain hole 61, thereby returning to the oil pool 11 to achieve the recycling of the coolant. In addition, the coolant dripping from the oil retaining ring 60 can also cool the stator windings 52 at both ends. It can be understood that the number, aperture, shape and arrangement position of the oil drain holes 61 can be adjusted according to actual needs.

[0050] Figure 6 is a second cross-sectional schematic diagram of an embodiment of an electric drive system according to the present invention; Figure 7 is a structural schematic diagram of an embodiment of a rotor of an electric drive system according to the present invention; and Figure 8 is a cross-sectional schematic diagram of an embodiment of a rotor core of an electric drive system according to the present invention. As shown in Figures 2 and 6, in one or more embodiments, rotor 70 includes a rotor shaft 71 and a rotor core 72 surrounding rotor shaft 71. Rotor shaft 71 has a central cavity 711 extending along its central axis. Central cavity 711 communicates with rotor-side oil distribution passage 130. In one or more embodiments, four oil-slinging holes 712 are provided on rotor shaft 71, spaced apart from one another. Alternatively, the number of oil-slinging holes 712 may be greater or less than four, for example, three or five. In one or more embodiments, the multiple oil-slinging holes 712 are evenly spaced along the circumference of rotor shaft 71 to improve coolant uniformity. Based on the orientations shown in Figures 2 and 7, rotor core 72 is positioned to the left of rotor shaft 71. An input gear 713 is provided on the right side of the rotor shaft 71 for connection to the reducer 90. Referring to Figures 6 and 8 , four oil guide grooves 73 are formed between the rotor shaft 71 and the rotor core 72, spaced apart from each other. Each oil guide groove 73 is connected to a corresponding oil-slinging hole 712, allowing coolant within the central cavity 711 to flow into the oil guide groove 73 through the oil-slinging hole 712. In one or more embodiments, the oil-slinging hole 712 is positioned in the middle of the rotor core 72, allowing coolant flowing into the oil guide groove 73 through the oil-slinging hole 712 to flow to the left and right ends.

[0051] Continuing with Figures 2 and 6 , in one or more embodiments, dynamic balancing plates 80 are further provided at the left and right ends of the rotor core 72. The dynamic balancing plates 80 are fixed to the rotor core 72 so that when the rotor shaft 71 rotates, the dynamic balancing plates 80 and the rotor core 72 rotate together. Figure 9 is a schematic structural diagram of an embodiment of a dynamic balancing plate in an electric drive system according to the present invention. As shown in Figure 9 , in one or more embodiments, each dynamic balancing plate 80 is provided with four spaced-apart dynamic balancing plate oil inlet holes 813 and four spaced-apart dynamic balancing plate oil outlet holes 823. Referring to Figure 8 , in one or more embodiments, eight spaced-apart rotor core oil guide channels 721 are provided on the rotor core 72. Each rotor core oil guide channel 721 extends through the rotor core 72. In one or more embodiments, each rotor core oil guide channel 721 is arranged spirally around the central axis of the rotor shaft 71 to extend the oil path and improve cooling efficiency. Each dynamic balancing plate oil inlet hole 813 and each dynamic balancing plate oil outlet hole 823 is connected to a corresponding oil guide groove 73. In addition, the dynamic balancing plate oil inlet hole 813 on each dynamic balancing plate 80 is connected to the dynamic balancing plate oil outlet hole 823 on another dynamic balancing plate 80 through the corresponding rotor core oil guide channel 721 .

[0052] Continuing with FIG. 9 , in one or more embodiments, each dynamic balancing plate 80 is provided with four spaced-apart first L-shaped oil guide structures. Each first L-shaped oil guide structure includes a first radial segment 811 and a first circumferential segment 812 that are connected to each other. The first radial segment 811 extends generally radially of the dynamic balancing plate 80, while the first circumferential segment 812 extends generally circumferentially of the dynamic balancing plate 80. The first radial segment 811 is connected to the oil guide groove 73, and the dynamic balancing plate oil inlet 813 is provided in the first circumferential segment 812. Therefore, coolant flowing out of the oil guide groove 73 passes through the first radial segment 811 and the first circumferential segment 812 in sequence and enters the rotor core oil guide channel 721 through the dynamic balancing plate oil inlet 813. In one or more embodiments, each dynamic balancing plate 80 is provided with four second L-shaped oil guide structures that are spaced-apart from the first L-shaped oil guide structures. Each second L-shaped oil guide structure includes a second radial segment 822 and a second circumferential segment 821 that are connected to each other. The second radial section 822 extends approximately along the radial direction of the dynamic balancing plate 80, while the second circumferential section 821 extends approximately along the circumference of the dynamic balancing plate 80. The dynamic balancing plate oil outlet hole 823 is provided on the second circumferential section 821. Therefore, the coolant discharged from the rotor core oil guide channel 721 will be discharged from the dynamic balancing plate oil outlet hole 823 on the second L-shaped oil guide structure, and will pass through the second circumferential section 821 and the second radial section 822 in sequence, and then flow back to the oil pool 11 along the outer wall of the dynamic balancing plate 80 to achieve the recycling of the coolant. In one or more embodiments, two auxiliary oil outlet holes of the dynamic balancing plate 80 are provided on each dynamic balancing plate 80, spaced apart from each other. Each auxiliary oil outlet hole of the dynamic balancing plate 80 penetrates the dynamic balancing plate 80, so that the coolant between the rotor core 72 and the dynamic balancing plate 80 can be smoothly discharged through the auxiliary oil outlet hole of the dynamic balancing plate 80. Alternatively, the number of auxiliary oil outlet holes of the dynamic balancing plate 80 can also be set to other suitable numbers more or less than two, such as one, three, etc.

[0053] Figure 10 is a third cross-sectional schematic diagram of an embodiment of the electric drive system of the present invention; Figure 11 is a schematic structural diagram of an embodiment of the housing and liquid distribution pipe of the electric drive system of the present invention. As shown in Figures 10 and 11, in one or more embodiments, the electric drive system 1 further includes a liquid distribution pipe 170 connected to the reducer-side oil distribution channel 140. Liquid distribution pipe 170 has multiple branch pipes spaced apart from each other, and at least some of the branch pipes can direct coolant to the reducer 90.

[0054] Continuing with Figures 10 and 11 , in one or more embodiments, the reducer 90 includes an intermediate shaft 91 that meshes with the input gear 713 of the rotor 70 . Specifically, the intermediate shaft 91 includes a coaxial first gear 911 and a second gear 912 . The first gear 911 meshes with the input gear 713 . The reducer 90 also includes an output gear 92 that meshes with the second gear 912 . Furthermore, the intermediate shaft 91 includes a first intermediate shaft bearing and a second intermediate shaft bearing (not shown) for supporting the intermediate shaft 91 . Multiple branch pipes include a first branch pipe 171 that mates with the first intermediate shaft bearing, a second branch pipe 172 that mates with the second intermediate shaft bearing, and a third branch pipe 173 that mates with the meshing portion between the intermediate shaft 91 and the input gear 713 . After flowing through the first and second intermediate shaft bearings, as well as the meshing portion between the intermediate shaft 91 and the input gear 713 , the coolant, under its own weight, flows back to the oil sump 11 , thereby achieving coolant recycling.

[0055] Continuing with FIG2 , in one or more embodiments, the rotor 70 includes a first rotor bearing 74 located near the reducer 90, a second rotor bearing 75 located away from the reducer 90, and a third rotor bearing 76 located between the first and second rotor bearings 74, 75. Referring to FIG11 , the plurality of branch pipes further includes a fourth branch pipe 174 corresponding to the first rotor bearing 74 and a fifth branch pipe 175 corresponding to the third rotor bearing 76. Through the above arrangement, the liquid distribution pipe 170 can direct a portion of the coolant in the reducer-side oil distribution path 140 to the first and third rotor bearings 74, 76, to cool and lubricate the rotor 70. After flowing through the first and third rotor bearings 74, 76, the coolant will flow back to the oil pool 11 under its own weight, thereby achieving recycling of the coolant.

[0056] Continuing with FIG. 2 , in one or more embodiments, the oil circuit mechanism 100 further includes a rotor bearing oil passage 150. The rotor bearing oil passage 150 communicates with the stator-side oil passage 120 to direct a portion of the coolant within the stator-side oil passage 120 to the rotor's second bearing 75. Accordingly, after flowing through the second bearing 75, the coolant, under its own weight, flows back into the oil reservoir 11, thereby recycling the coolant. In one or more embodiments, a flow restrictor 160 is further provided within the rotor bearing oil passage 150 to regulate the coolant flow within the rotor bearing oil passage 150.

[0057] To address or, to a certain extent, improve the technical problem that oil cooling methods in the prior art cannot meet the overall cooling requirements of electric drive systems, the present invention further provides a vehicle (not shown). The vehicle includes the electric drive system 1 described in any of the above embodiments. The vehicle can be an electric vehicle or a hybrid vehicle. The vehicle can be of any model, such as a sedan, SUV, or MPV.

[0058] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. An electric drive system, characterized in that: The electric drive system comprises: stator; a rotor, the rotor being matched with the stator; a speed reducer connected to the rotor; and An oil circuit mechanism includes a main oil circuit for conveying coolant and a stator-side branch oil circuit, a rotor-side branch oil circuit and a reducer-side branch oil circuit respectively connected to the main oil circuit, so as to convey the coolant to the stator, the rotor and the reducer at the same time.

2. The electric drive system according to claim 1, characterized in that: The main oil circuit is provided with a stator side oil inlet hole, a rotor side oil inlet hole and a reducer side oil inlet hole which are spaced apart from each other, wherein the stator side oil inlet hole is connected to the stator side branch oil circuit, the rotor side oil inlet hole is connected to the rotor side branch oil circuit, and the reducer side oil inlet hole is connected to the reducer side branch oil circuit.

3. The electric drive system according to claim 1, characterized in that: The stator comprises: The stator core has a stator core oil inlet connected to the stator side oil distribution path in the middle of the stator core, and stator core oil outlets are respectively provided at the left and right ends of the stator core, and the stator core oil outlet is connected to the stator core oil inlet through a stator core oil guide channel.

4. The electric drive system according to claim 3, characterized in that: The stator core oil inlet is arranged at the top of the stator core.

5. The electric drive system according to claim 3, characterized in that: The stator core is formed by stacking a plurality of silicon steel sheets in sequence, wherein adjacent silicon steel sheets are arranged in a staggered manner, and each silicon steel sheet is provided with oil holes spaced apart from each other, so that the oil holes on all the silicon steel sheets together form the stator core oil guide channel which is spirally arranged around the central axis of the stator core.

6. The electric drive system according to claim 3, characterized in that: Oil retaining rings are respectively provided at the left and right ends of the stator core, and a plurality of oil drain holes spaced apart from each other are opened on each of the oil retaining rings, so that the coolant flowing out of the oil outlet of the stator core can be discharged through the oil drain holes.

7. The electric drive system according to claim 1, characterized in that: The rotor comprises: A rotor shaft body, on which a central cavity connected to the rotor-side oil distribution path and a plurality of oil-slinging holes spaced apart from each other are provided, and each of the oil-slinging holes is connected to the central cavity; and The rotor core is surrounded by the rotor shaft, and a plurality of oil guide grooves are spaced between the rotor core and the rotor shaft, and each of the oil guide grooves is connected to a corresponding oil throwing hole.

8. The electric drive system according to claim 7, characterized in that: The plurality of oil-slinging holes are evenly spaced apart along the circumference of the rotor shaft.

9. The electric drive system according to claim 7, characterized in that: A plurality of rotor core oil guide passages spaced apart from each other are provided on the rotor core; Dynamic balancing plates are respectively provided at both ends of the rotor core, and dynamic balancing plate oil inlet holes and dynamic balancing plate oil outlet holes spaced apart from each other are provided on the dynamic balancing plate, each of the dynamic balancing plate oil inlet holes and the dynamic balancing plate oil outlet holes are communicated with the corresponding oil guide grooves, and the dynamic balancing plate oil inlet hole on each dynamic balancing plate is communicated with the dynamic balancing plate oil outlet hole on another dynamic balancing plate through the corresponding rotor core oil guide channel.

10. The electric drive system according to claim 9, characterized in that: A first L-shaped oil guiding structure is provided on each of the dynamic balancing plates, and the first L-shaped oil guiding structure includes a first radial section and a first circumferential section connected to each other, wherein the first radial section is connected to the oil guiding groove, and the oil inlet hole of the dynamic balancing plate is opened on the first circumferential section.

11. The electric drive system according to claim 10, characterized in that: A second L-shaped oil guiding structure separated from the first L-shaped oil guiding structure is provided on each of the dynamic balancing plates, the second L-shaped oil guiding structure comprising a second radial segment and a second circumferential segment connected to each other, wherein the oil outlet hole of the dynamic balancing plate is opened on the second circumferential segment.

12. The electric drive system according to claim 9, characterized in that: Each rotor core oil guide channel is spirally arranged around the central axis of the rotor shaft body.

13. The electric drive system according to claim 1, characterized in that: The electric drive system further includes a liquid distribution pipe connected to the oil distribution path on the reducer side, wherein the liquid distribution pipe has a plurality of branch pipes spaced apart from each other, and at least part of the branch pipes can guide the coolant to the reducer.

14. The electric drive system according to claim 13, characterized in that: The speed reducer includes an intermediate shaft meshed with an input gear of the rotor, the intermediate shaft having an intermediate shaft first bearing and an intermediate shaft second bearing for supporting the intermediate shaft; and The plurality of branch pipes include a first branch pipe matched with a first bearing of the intermediate shaft, a second branch pipe matched with a second bearing of the intermediate shaft, and a third branch pipe matched with a meshing portion of the intermediate shaft and the input gear.

15. The electric drive system according to claim 13, characterized in that: The rotor has a first rotor bearing close to the reducer, a second rotor bearing far from the reducer, and a third rotor bearing located between the first rotor bearing and the second rotor bearing; and The plurality of branch pipes further include a fourth branch pipe matched with the first bearing of the rotor and a fifth branch pipe matched with the third bearing of the rotor.

16. The electric drive system according to claim 14, characterized in that: The oil circuit mechanism further includes a rotor bearing oil branch circuit, and the rotor bearing oil branch circuit is connected to the stator side oil branch circuit so as to guide part of the coolant in the stator side oil branch circuit to the rotor second bearing.

17. The electric drive system according to any one of claims 1 to 16, characterized in that: The electric drive system also includes a casing, the stator, the rotor and the reducer are all arranged in the casing, and the stator-side oil branch path, the rotor-side oil branch path and the reducer-side oil branch path are all integrally formed with the casing.

18. A vehicle, characterized in that: The vehicle comprises an electric drive system according to any one of claims 1-17.

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