Electric drive system cooling structure and electric drive system with same

Abstract

The application provides an electric drive system cooling structure and an electric drive system with the same. The electric drive system cooling structure comprises a rotor assembly cooling structure, which comprises: a rotor shaft, an inner part of the rotor shaft having an oil cavity containing oil; two dynamic balance plates, one of the two dynamic balance plates being provided with an oil inlet groove, the other of the two dynamic balance plates being provided with an oil outlet groove, the oil outlet groove being provided with an oil throwing hole penetrating through the dynamic balance plate at an end away from the rotor shaft, the oil throwing hole being arranged close to a winding of a stator assembly, and the oil inlet groove being in communication with the oil cavity; and an inner part of a rotor core group being provided with a cooling oil channel, two ends of the cooling oil channel being in communication with the oil inlet groove and the oil outlet groove respectively; wherein, when the rotor shaft rotates, part of the oil entering the cooling oil channel can perform cooling operation on the inner part of the rotor core group, and part of the oil thrown out by the oil throwing hole can perform cooling operation on the winding of the stator assembly. The application solves the problem of poor cooling effect of the electric drive cooling system in the prior art.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric drive system design, in particular to an electric drive system cooling structure and an electric drive system with the same. BACKGROUND

[0002] With the development of hybrid electric vehicles, hybrid electric drive systems are developing towards high integration, high speed and high efficiency. Therefore, the structure is more compact, the system integration is higher, and at the same time, to meet the higher power generation and driving efficiency, the cooling and lubricating system is required to be higher. The conventional hybrid electric drive system needs to consider the electromagnetic performance scheme, structure and material process scheme, system integration scheme, etc. of the electric drive system to meet the system efficiency requirement, realizes the effective operation of the system through the hybrid power series-parallel configuration, and reasonable cooling and lubricating system design plays an important role in improving the system efficiency and meeting the vehicle mileage requirement.

[0003] The electric drive cooling system includes generator cooling and drive motor cooling, both of which include stator cooling and rotor cooling. In the prior art (CN214888767U), the stator assembly is sprayed and the rotor assembly is internally cooled, but the stator winding cannot be cooled by the rotor internal cooling scheme, so this scheme cannot fully meet the heat dissipation requirement of the stator winding, thereby resulting in poor cooling effect of the electric drive system cooling structure. At the same time, the stator is sprayed by the pipeline on the shell, and since the spraying hole position is far away from the winding position, the electric drive internal high-speed oil throwing will also cause the bubble phenomenon.

[0004] In view of the above problems in the prior art, no effective solution has been proposed so far. SUMMARY

[0005] The main purpose of the present application is to provide an electric drive system cooling structure and an electric drive system with the same, so as to solve the problem of poor cooling effect of the electric drive cooling system in the prior art.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present application, an electric drive system cooling structure is provided, which comprises a rotor assembly cooling structure, the rotor assembly cooling structure comprising: a rotor shaft, the inside of the rotor shaft having an oil cavity containing oil; two dynamic balance plates, both of which are connected with the rotor shaft and are arranged in the axial direction of the rotor shaft, one of the two dynamic balance plates being provided with an oil inlet groove, the other of the two dynamic balance plates being provided with an oil outlet groove, the oil outlet groove being provided with an oil throwing hole penetrating the dynamic balance plate at the end away from the rotor shaft, the oil throwing hole being arranged close to the winding of the stator assembly, the oil inlet groove being in communication with the oil cavity; and a rotor core group, which is arranged between the two dynamic balance plates, is connected with the rotor shaft, and is provided with a cooling oil channel inside, both ends of the cooling oil channel being in communication with the oil inlet groove and the oil outlet groove; wherein when the rotor shaft rotates, part of the oil entering the cooling oil channel can perform cooling operation on the inside of the rotor core group, and part of the oil thrown out by the oil throwing hole can perform cooling operation on the winding of the stator assembly.

[0007] Further, the rotor assembly cooling structure further comprises: a rotor oil injection pipe, which is arranged inside the rotor shaft, is provided with at least one oil outlet on the rotor oil injection pipe, and is in communication with the oil cavity through the oil outlet to perform cooling operation on the inside of the oil cavity, wherein the first end of the rotor shaft in the direction of its own axis is connected with the rear end cover of the electric drive system, the second end of the rotor shaft in the direction of its own axis is connected with the transmission of the electric drive system through a spline, the oil inlet end of the rotor oil injection pipe is connected with the second end of the rotor shaft through a connecting piece, the first end of the rotor shaft is provided with a first bearing, and the connecting piece and the first bearing form a first cooling cavity; and an oil guide end pad, which is connected with the bearing hole of the rear end cover, is provided with a rotor oil inlet located in the middle and a bearing oil inlet hole located at the edge, the rotor oil inlet is in communication with the oil inlet end of the rotor oil injection pipe, and the bearing oil inlet hole is in communication with the first cooling cavity, so that the oil performs cooling operation on the first bearing.

[0008] Further, the dynamic balance plate comprises a first dynamic balance plate and a second dynamic balance plate arranged at both ends of the outer side wall of the oil cavity respectively, the first dynamic balance plate is connected with the rotor shaft, the first dynamic balance plate is provided with a plurality of oil inlet grooves arranged in the circumferential direction of the first dynamic balance plate at intervals, the first dynamic balance plate is provided with a plurality of oil outlet grooves arranged in the circumferential direction of the first dynamic balance plate at intervals, the second dynamic balance plate is arranged opposite to the first dynamic balance plate in the axial direction of the rotor shaft, and the second dynamic balance plate is arranged in the same structure as the first dynamic balance plate, wherein the first dynamic balance plate and the second dynamic balance plate are installed on the rotor shaft at a preset angle, so that each oil inlet groove of the first dynamic balance plate and each oil outlet groove of the second dynamic balance plate are arranged one by one in correspondence, and each oil inlet groove of the second dynamic balance plate and each oil outlet groove of the first dynamic balance plate are arranged one by one in correspondence.

[0009] Further, the rotor core assembly includes a plurality of magnetic steel sheets stacked between the first dynamic balance plate and the second dynamic balance plate, each magnetic steel sheet is arranged in the same structure, and each magnetic steel sheet is circumferentially provided with a plurality of flow guide holes. The plurality of magnetic steel sheets are stacked to form a plurality of cooling oil channels with the plurality of flow guide holes coaxially arranged on different magnetic steel sheets. The two ends of part of the cooling oil channels are respectively communicated with the oil inlet grooves of the first dynamic balance plate and the oil outlet grooves of the second dynamic balance plate. The two ends of another part of the cooling oil channels are respectively communicated with the oil inlet grooves of the second dynamic balance plate and the oil outlet grooves of the first dynamic balance plate.

[0010] Further, the second end of the rotor shaft is provided with a second bearing, the second end of the rotor shaft is provided with a rotary transformer rotor pressure ring, the rotary transformer rotor pressure ring is arranged adjacent to the second bearing, the rotary transformer rotor pressure ring has an oil blocking structure facing the second bearing, the oil blocking structure, the second bearing and part of the side wall of the rotor shaft form a second cooling cavity, the first oil hole is arranged in the rotor shaft, the first oil hole is communicated with the second cooling cavity, and part of the oil in the rotor oil injection pipe can enter the second cooling cavity through the first oil hole to cool the second bearing.

[0011] Further, the second end of the rotor shaft is provided with a second bearing, the second end of the rotor shaft is provided with a rotary transformer rotor pressure ring, the rotary transformer rotor pressure ring is arranged adjacent to the second bearing, the rotary transformer rotor pressure ring has an oil blocking structure facing the second bearing, the oil blocking structure, the second bearing and part of the side wall of the rotor shaft form a second cooling cavity, the first oil hole is arranged in the rotor shaft, the first oil hole is communicated with the second cooling cavity, and part of the oil in the rotor oil injection pipe can enter the second cooling cavity through the first oil hole to cool the second bearing.

[0012] Further, a plurality of third oil holes are arranged at both ends of the oil cavity of the rotor shaft, the oil cavity is communicated with each oil inlet groove of the first dynamic balance plate through part of the third oil holes, and the oil cavity is communicated with each oil inlet groove of the second dynamic balance plate through another part of the third oil holes.

[0013] Further, the rotor assembly cooling structure is arranged on the rotor assembly of the generator of the electric drive system, and the rotor assembly cooling structure is connected with the generator stator assembly, and / or the rotor assembly cooling structure is arranged on the rotor assembly of the driving motor of the electric drive system, and the rotor assembly cooling structure is connected with the driving motor stator assembly.

[0014] Further, the electric drive system cooling structure further includes a stator cooling assembly structure, the stator cooling assembly structure includes a generator stator oil injection pipe and a driving motor stator oil injection pipe, at least one of the generator stator oil injection pipe and the driving motor stator oil injection pipe includes a bypass oil path, and the bypass oil path extends into the housing of the transmission to cool the transmission end bearing.

[0015] According to another aspect of the present application, there is provided an electric drive system, the electric drive system comprising an electric drive system cooling structure, the electric drive system cooling structure being the electric drive system cooling structure described above.

[0016] The application has the advantages that the oil inlet groove is arranged on one of the two dynamic balance plates, the oil outlet groove is arranged on the other one of the two dynamic balance plates, and the cooling oil channel is arranged inside the rotor core group, so that the three can form a channel for circulating and flowing of the oil, and the oil can cool the inside of the rotor core group, and the oil throwing hole on the oil outlet groove can cool the winding of the stator assembly close to the oil throwing hole, so that the cooling structure inside the rotor can meet the heat dissipation requirement of the stator winding, and the oil throwing hole is close to the winding of the stator assembly, so that the bubble phenomenon caused by high-speed oil throwing can be prevented. The application effectively solves the problem of poor cooling effect of the electric drive cooling system in the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which form a part of the present description, illustrate further aspects of the present application, and together with the description serve to explain the principles of the present application. In the drawings:

[0018] Figure 1 A structure schematic view of a first embodiment of a rotor assembly cooling structure according to the present application is shown;

[0019] Figure 2 A structure schematic view of a second embodiment of a rotor assembly cooling structure according to the present application is shown;

[0020] Figure 3 A structure schematic view of a first embodiment of a dynamic balance plate according to the present application is shown;

[0021] Figure 4 A structure schematic view of a second embodiment of a dynamic balance plate according to the present application is shown;

[0022] Figure 5 A structure schematic view of a first embodiment of an electric drive system cooling structure according to the present application is shown;

[0023] Figure 6 A structure schematic view of a second embodiment of an electric drive system cooling structure according to the present application is shown;

[0024] Figure 7 A structure schematic view of a third embodiment of an electric drive system cooling structure according to the present application is shown;

[0025] Figure 8 A structure schematic view of a third embodiment of a rotor assembly cooling structure according to the present application is shown.

[0026] Wherein, the above figures include the following reference signs:

[0027] 10, oil cavity; 101, generator stator assembly; 102, generator rotor assembly; 103, drive motor stator assembly; 104, drive motor rotor assembly; 105, transmission; 106, all-in-one inverter assembly; 109, transmission front shell; 110, transmission rear shell; 111, rotor shaft; 1111, first oil hole; 1112, third cooling cavity; 112, bowl-shaped plug; 113, spline; 114, output shaft sealing ring; 115, rotor oil injection pipe; 1151, oil outlet; 1152, connecting piece; 1153, first cooling cavity; 116, high and low voltage integrated terminal block;

[0028] 20, dynamic balance plate; 201, oil guide end pad; 202, rotor oil inlet; 203, bearing oil inlet hole; 207, oil inlet channel; 208, generator oil channel; 209, drive motor oil channel;

[0029] 401, magnetic steel sheet; 4010, flow guide hole; 402, first dynamic balance plate; 403, second dynamic balance plate; 404, resolver rotor pressure ring; 4041, oil blocking structure; 4042, second cooling cavity; 4043, first oil hole; 406, second bearing; 407, first bearing; 408, resolver rotor assembly; 409, third oil hole; 410, oil inlet groove; 411, cooling oil channel; 412, oil outlet groove; 413, oil throwing hole;

[0030] 30, rotor core group; 301, generator stator oil injection pipe; 302, drive motor stator oil injection pipe; 303, rear end cover; 305, cooler; 306, pressure filter; 307, cooling oil pump. DETAILED DESCRIPTION

[0031] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] It should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and it should also be understood that, when the terms "comprise" and / or "include" are used in the specification, there is a presence of a feature, step, operation, device, component and / or combination thereof.

[0033] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, unless the contrary is indicated. For example, the description of the example embodiments is intended to include equivalents, modifications, and variations of the example embodiments. The terms "including", "comprising", "having" and variations thereof as used herein are intended to be inclusive in a manner similar to the term "comprising" as "comprising" is interpreted when employed as a transitional term in a claim. Furthermore, the description is intended to cover all possible combinations with two or more of the described features, steps, components, objects, materials, acts, functions, etc. The terminology includes the expressions "first", "second", and so on only for distinguishing between similar objects discussed in the specification and is not otherwise intended to limit the scope of the example embodiments or to imply that the example embodiments relate only to the relative placement or order of the features recited.

[0034] Example embodiments according to the present application will now be described in detail with reference to the accompanying drawings. However, these example embodiments can be implemented in various different forms and should not be construed as being limited to only the embodiments set forth herein. It is understood that the embodiments are provided so as to make the disclosure of the present application complete and comprehensive, and to fully convey the concept of the example embodiments to those having ordinary skill in the art, and in the drawings, the thicknesses of layers and regions are exaggerated for clarity, and the same reference numerals are used throughout the drawings to designate the same elements, and thus a repeated description thereof will be omitted.

[0035] In conjunction with Figures 1 to 8 As shown, according to specific embodiments of the present application, an electric drive system cooling structure is provided.

[0036] The electric drive system cooling structure includes a rotor assembly cooling structure, which includes a rotor shaft 111, dynamic balance plates 20, and a rotor core set 30. The rotor shaft 111 has an oil cavity 10 inside to accommodate oil. The dynamic balance plates 20 are two. Both of the dynamic balance plates 20 are connected with the rotor shaft 111. The two dynamic balance plates 20 are arranged in an axial direction of the rotor shaft 111. One of the two dynamic balance plates 20 is provided with an oil inlet groove 410. The other of the two dynamic balance plates 20 is provided with an oil outlet groove 412. The oil outlet groove 412 is provided with an oil throwing hole 413 penetrating the dynamic balance plate 20 at an end away from the rotor shaft 111. The oil throwing hole 413 is arranged close to a winding of a stator assembly. The oil inlet groove 410 is in communication with the oil cavity 10. The rotor core set 30 is arranged between the two dynamic balance plates 20. The rotor core set 30 is connected with the rotor shaft 111. The rotor core set 30 is internally provided with a cooling oil channel 411. Both ends of the cooling oil channel 411 are in communication with the oil inlet groove 410 and the oil outlet groove 412, respectively. When the rotor shaft 111 rotates, part of the oil entering the cooling oil channel 411 can perform cooling work on the inside of the rotor core set 30, and part of the oil thrown out by the oil throwing hole 413 can perform cooling work on the winding of the stator assembly.

[0037] The application has the advantages that the oil inlet groove 410 is arranged on one of the two dynamic balance plates 20, the oil outlet groove 412 is arranged on the other one of the two dynamic balance plates 20, and the cooling oil channel 411 is arranged inside the rotor core group 30, so that the three can form a channel for circulating and flowing of the oil, and the oil can cool the inside of the rotor core group 30, and the oil throwing hole 413 on the oil outlet groove 412 can cool the winding of the stator assembly close to the oil throwing hole 413, so that the cooling effect of the electric drive cooling system in the prior art is improved.

[0038] As shown in Figures 5 to 7 The hybrid electric drive system is composed of a generator stator assembly 101, a generator rotor assembly 102, a drive motor stator assembly 103, a drive motor rotor assembly 104, a transmission 105 and a multi-in-one inverter assembly 106. The generator stator assembly 101, the generator rotor assembly 102, the drive motor stator assembly 103 and the drive motor rotor assembly 104 are integrated in the transmission 105 housing, and the multi-in-one inverter assembly 106 is fixed on the transmission 105. The generator stator assembly 101 and the drive motor stator assembly 103 are fixed on the transmission housing by three bolts respectively, and the stator high-voltage three-phase is connected with the high-low voltage integrated terminal block 116, and the multi-in-one inverter assembly 106 is also connected with the stator three-phase through the high-low voltage integrated terminal block 116, and the high-low voltage integrated terminal block 116 assembly connects the internal rotary variable of the motor, the temperature sensor signal and introduces them into the multi-in-one inverter assembly 106. In addition to considering the overall oil circuit cooling design, the technical scheme of the embodiment increases the consideration of system integration design, realizes the wiring inside the closed cavity and reduces the low-voltage conduction radiation, and improves the EMC level requirement through the high-low voltage terminal block integrated design. The transmission 105 and the motor share the housing, and the oil cooling scheme is used for motor cooling and gear lubrication, so that the integration degree is improved.

[0039] It should be noted that the rotor assembly cooling structure in the above embodiment is suitable for the generator rotor assembly and the drive motor rotor assembly, and is also suitable for the non-hybrid power configuration electric drive.

[0040] As shown in the figure, the rotor assembly cooling structure further comprises a rotor oil injection pipe 115 and an oil guide end pad 201. The rotor oil injection pipe 115 is arranged inside the rotor shaft 111. The rotor oil injection pipe 115 is provided with at least one oil outlet 1151. The rotor oil injection pipe 115 communicates with the oil cavity 10 through the oil outlet 1151 to perform cooling operation inside the oil cavity 10. The first end of the rotor shaft 111 along the axis direction thereof is connected with the rear end cover 303 of the electric drive system, and the second end of the rotor shaft 111 along the axis direction thereof is connected with the transmission 105 of the electric drive system through the spline 113. The oil inlet end of the rotor oil injection pipe 115 is connected with the second end of the rotor shaft 111 through a connecting piece 1152. The first end of the rotor shaft 111 is provided with a first bearing 407, and the first bearing 407 and the connecting piece 1152 form a first cooling cavity 1153. The oil guide end pad 201 is connected with the bearing hole of the rear end cover 303. The oil guide end pad 201 is provided with a rotor oil inlet 202 at the middle part and a bearing oil inlet hole 203 at the edge. The rotor oil inlet 202 communicates with the oil inlet end of the rotor oil injection pipe 115. The bearing oil inlet hole 203 communicates with the first cooling cavity 1153 to perform cooling operation on the first bearing 407. By using the above scheme, the cooling and lubrication of the first bearing 407 are realized, and the internal spray cooling of the rotor shaft 111 is also realized.

[0041] As shown in the figure, Figure 5 The gear set of the hybrid electric drive system is arranged inside the transmission front shell 109 and the transmission rear shell 110, and the drive motor stator assembly and the drive motor rotor assembly, and the generator stator assembly and the generator rotor assembly share the transmission rear shell 110. The drive motor stator assembly 103 and the generator stator assembly 101 adopt a 6-layer flat wire winding scheme. The generator rotor assembly 102 and the drive motor rotor assembly 104 contain a rotor oil injection pipe 115 which is integratedly arranged inside the rotor shaft 111. The cooling oil enters the inside of the rotor oil injection pipe 115 to perform internal spray cooling of the rotor shaft 111, and multiple oil injection holes are arranged inside the rotor shaft 111 to spray the cooling oil.

[0042] As shown in the figure, Figure 6 The motor rear end cover is internally integrated with a generator oil channel 208 and a drive motor oil channel 209. The oil guide end pad 201 is assembled in the bearing hole position of the motor rear end cover by interference fit. The oil guide end pad 201 contains a rotor oil inlet 202 and a bearing oil inlet hole 203 to perform cooling for the rear end bearing of the rotor and the inside of the rotor, respectively. The cooling oil enters the oil inlet channel 207 from the motor rear end cover, and then enters the generator oil channel 208 and the drive motor oil channel 209, respectively. The lubrication and cooling system of the electric drive system comprises an internal oil channel of the transmission rear end cover, a stator spray oil channel, an internal rotor oil throwing channel, and a gear lubrication oil channel.

[0043] As shown in the figure, Figure 1 and Figure 2As shown, the dynamic balance plate 20 includes a first dynamic balance plate 402 and a second dynamic balance plate 403 respectively arranged at both ends of the outer side wall of the oil cavity 10. The first dynamic balance plate 402 is connected with the rotor shaft 111. The first dynamic balance plate 402 is spaced apart along the circumferential direction of the first dynamic balance plate 402 and is provided with a plurality of oil inlet grooves 410. The first dynamic balance plate 402 is spaced apart along the circumferential direction of the first dynamic balance plate 402 and is provided with a plurality of oil outlet grooves 412. The second dynamic balance plate 403 is arranged opposite to the first dynamic balance plate 402 along the axis direction of the rotor shaft 111. The second dynamic balance plate 403 is arranged in the same structure as the first dynamic balance plate 402. The first dynamic balance plate 402 and the second dynamic balance plate 403 are installed on the rotor shaft 111 at a preset angle, so that each oil inlet groove 410 of the first dynamic balance plate 402 and each oil outlet groove 412 of the second dynamic balance plate 403 are arranged one by one, and each oil inlet groove 410 of the second dynamic balance plate 403 and each oil outlet groove 412 of the first dynamic balance plate 402 are arranged one by one. The lubrication and cooling system of the electric drive system includes a transmission rear end cover internal oil circuit, a stator spraying oil circuit, a rotor internal oil throwing circuit, and a gear lubricating oil circuit. A single oil inlet groove 410, a single oil outlet groove 412, and a single cooling oil channel 411 form a rotor internal oil throwing circuit. Such arrangement not only cools the magnetic steel sheet 401, but also sets up an oil throwing circuit to spray the stator winding, effectively improving the cooling efficiency. Figure 2 and Figure 3 As shown, the first dynamic balance plate 402 is provided with four oil inlet grooves 410 and four oil outlet grooves 412. Similarly, the second dynamic balance plate 403 is also provided with four oil inlet grooves 410 and four oil outlet grooves 412. The magnetic steel sheet 401 is provided with eight flow guide holes 4010, so that the rotor core group 30 has eight cooling channels. The first dynamic balance plate 402 and the second dynamic balance plate 403 are installed on the rotor shaft at an angle of 45°. Among them, the four oil inlet grooves 410 on the first dynamic balance plate 402, four of the eight cooling channels, and the oil outlet grooves 412 on the second dynamic balance plate 403 form four complete cooling liquid channels one by one, and the cooling oil flows in the cooling liquid channels in the first direction. The four oil inlet grooves 410 on the second dynamic balance plate 403, four of the eight cooling channels, and the oil outlet grooves 412 on the first dynamic balance plate 402 form four complete cooling liquid channels one by one, and the cooling oil flows in the cooling liquid channels in the second direction. Among them, the first direction and the second direction are coaxial and opposite. In this way, bidirectional cooling inside the rotor assembly is realized, the cooling efficiency is improved, and the temperature of the permanent magnet is reduced.

[0044] Adopt the technical scheme of the application, the rotor internal cooling is carried out through the oil cooling distribution inside the rear end cover of the transmission, the rotor shaft is welded or spin formed, the rotor shaft internal cooling is carried out through the integrated oil injection pipe inside, the rotor assembly is provided with oil injection holes on the two sides close to the dynamic balance plate, the cooling oil channel is established inside the dynamic balance plate, the high-speed oil is thrown to the end of the stator winding through the oil channel design, and the cooling efficiency is greatly improved.

[0045] The rotor assembly is composed of the magnetic steel sheet 401, the first dynamic balance plate 402, the second dynamic balance plate 403, the second bearing 406, the first bearing 407, the rotor shaft 111, the spin variable rotor assembly 408, the spin variable rotor pressure ring 404 and the iron core rear end pressure ring. The rotor shaft 111 internally contains the rotor oil injection pipe 115, the rotor oil injection pipe 115 is provided with an oil injection hole for internal spraying of the rotor shaft, meanwhile, the rotor shaft 111 is provided with oil holes at the first dynamic balance plate 402, the second dynamic balance plate 403, the spin variable rotor pressure ring 404 and the spline position respectively, meanwhile, the oil holes are blocked by the bowl-shaped plug 112 at the spline end, so that the cooling oil flows out from the corresponding positions respectively. The first dynamic balance plate 402 and the second dynamic balance plate 403 are provided with a drainage structure (i.e. the oil inlet groove 410), the spin variable rotor pressure ring 404 is provided with the oil blocking structure 4041 to fix the spin variable rotor assembly and lubricate the second bearing 406.

[0046] As shown in Figure 1 An oil cooling path of the rotor cooling assembly is shown, as shown in Figure 2 Another oil cooling path of the rotor cooling assembly is shown. The third oil holes 409 are respectively drained to the first dynamic balance plate 402 and the second dynamic balance plate 403 through the third oil holes 409 arranged on the rotor shaft, and then the bidirectional oil cooling path is realized through the internal flow channel of the iron core, the heat dissipation area is increased, and the heat dissipation efficiency is improved.

[0047] As shown in Figure 5 The rotor front and rear end dynamic balance plates (i.e. the first dynamic balance plate 402 and the second dynamic balance plate 403) contain the drainage structure (i.e. the oil inlet groove 410), correspond to the plurality of third oil holes 409 of the rotor shaft 111 respectively, the cooling oil enters the rotor iron core cooling oil channel 411 through the oil inlet groove 410 to cool the rotor iron core, and then is thrown out from the oil throwing hole 413 through the four oil outlet grooves 412 respectively to cool the winding end of the stator assembly. In the actual assembly process, the first dynamic balance plate 402 and the second dynamic balance plate 403 are installed at an angle of 45°, so that the bidirectional oil path cooling in the rotor can be realized.

[0048] The rotor core assembly 30 includes multiple magnetic steel plates 401 stacked between the first dynamic balancing plate 402 and the second dynamic balancing plate 403. Each magnetic steel plate 401 has an identical structure. Each magnetic steel plate 401 has multiple guide holes 4010 arranged circumferentially. The stacked arrangement of the multiple magnetic steel plates 401 allows the coaxially arranged guide holes 4010 on different magnetic steel plates 401 to form cooling oil channels 411. There are multiple cooling oil channels 411. The two ends of some cooling oil channels 411 are connected to the oil inlet groove 410 of the first dynamic balancing plate 402 and the oil outlet groove 412 of the second dynamic balancing plate 403, respectively; the two ends of other cooling oil channels 411 are connected to the oil inlet groove 410 of the second dynamic balancing plate 403 and the oil outlet groove 412 of the first dynamic balancing plate 402, respectively.

[0049] Preferably, a second bearing 406 is provided at the second end of the rotor shaft 111. A resolver rotor pressure ring 404 is provided at the second end of the rotor shaft 111. The resolver rotor pressure ring 404 is disposed adjacent to the second bearing 406. The resolver rotor pressure ring 404 has an oil-blocking structure 4041 facing the second bearing 406. The oil-blocking structure 4041, the second bearing 406, and part of the sidewall of the rotor shaft 111 form a second cooling chamber 4042. A first section oil hole 4043 is provided inside the rotor shaft 111. The first section oil hole 4043 communicates with the second cooling chamber 4042, and part of the oil in the rotor oil injection pipe 115 can enter the second cooling chamber 4042 through the first section oil hole 4043 to cool the second bearing 406. This arrangement improves the cooling effect on the second bearing 406 on the rotor shaft and prevents the drive assembly from becoming less efficient or even interrupted due to overheating of the second bearing 406.

[0050] In an optional embodiment, a cup-shaped plug 112 is provided inside the second end of the rotor shaft 111. A spline 113 is provided on the outer side wall of the second end of the rotor shaft 111. The rotor shaft 111 is connected to the transmission 105 via the spline 113. A second oil sluice hole 1111 is provided inside the rotor shaft 111. An output shaft seal 114 is provided on the outer side wall of the second end of the rotor shaft 111 near the spline 113. The output shaft seal 114, the spline 113, and part of the outer side wall of the rotor shaft 111 form a third cooling chamber 1112. The third cooling chamber 1112 communicates with the second oil sluice hole 1111, and part of the oil in the rotor oil injection pipe 115 can enter the third cooling chamber 1112 through the second oil sluice hole 1111 to cool the spline 113. The use of the output shaft seal 114 and the cup-shaped plug 112 near the spline 113 ensures that the cooling oil only lubricates the spline through the oil sluice hole on the spline side of the rotor shaft 111. Spline 113 is used to transmit torque from the rotor shaft to the gearbox. Its structural strength is affected by its own temperature. Cooling it using the solution in this embodiment can improve the stability of the electric drive operation.

[0051] As shown in Figure 2 The third oil hole 409 is arranged at both ends of the oil cavity 10 of the rotor shaft 111. The oil cavity 10 is communicated with each oil inlet groove 410 of the first dynamic balance plate 402 through part of the third oil hole 409, and the oil cavity 10 is communicated with each oil inlet groove 410 of the second dynamic balance plate 403 through another part of the third oil hole 409. In this way, the oil supply of the bidirectional cooling oil circuit can be realized.

[0052] Further, the rotor assembly cooling structure is arranged on the rotor assembly of the generator of the electric drive system, and is connected with the generator stator assembly 101, and / or the rotor assembly cooling structure is arranged on the rotor assembly of the drive motor of the electric drive system, and is connected with the drive motor stator assembly 103.

[0053] The electric drive system cooling structure further comprises a stator cooling assembly structure, and the stator cooling assembly structure comprises a generator stator oil injection pipe 301 and a drive motor stator oil injection pipe 302. At least one of the generator stator oil injection pipe 301 and the drive motor stator oil injection pipe 302 comprises a bypass oil circuit which extends into the housing of the transmission 105 to cool the transmission end bearing.

[0054] The cooling oil is filtered by the oil suction filter, enters the cooler 305, is cooled by the cooling water, and then is pumped into the rear end cover 303 by the pressure filter 306 and the cooling oil pump 307, and enters the drive motor and the generator through the oil paths on the rear end cover 303. The generator stator oil injection pipe 301 and the drive motor stator oil injection pipe 302 adopt a “Wang” or H-shaped pipe layout, and the specific structure form is not limited to the “Wang” or H-shaped pipe layout. The oil injection pipe is formed by welding an annular pipe and a straight pipe, and throttle holes are reasonably arranged on the annular pipe and the straight pipe. The straight pipe is used for cooling the winding end and the middle part of the core, and the annular pipe is mainly used for cooling the core. The drive motor stator oil injection pipe 302 and the generator stator oil injection pipe 301 respectively have a straight pipe extending into the transmission housing to form a transmission end bearing cooling oil path through the oil path in the transmission housing to cool the bearing.

[0055] The generator stator oil injection pipe 301 and the drive motor stator oil injection pipe 302 respectively spray and cool the winding end and the middle part of the stator core on both sides of the generator stator assembly 101 and the drive motor stator assembly 103. The generator stator oil injection pipe 301 and the drive motor stator oil injection pipe 302 are opened with throttle holes from top to bottom to spray, the stator assembly adopts a 6-layer flat wire scheme, and the core adopts an ultra-thin silicon steel adhesive core forming scheme.

[0056] The technical scheme of the embodiment is a hybrid spray cooling scheme, including a stator spray and a rotor spray design, the stator spray adopts an oil pipe scheme, the stator assembly is cooled through an external oil pipe, and the size of an oil hole on the outer wall of the oil pipe is determined through CFD simulation to meet the cooling requirement. Preferably, the external oil pipe is a ring-shaped H type, which is fixed on the shell by bolts, and the H type oil pipe extends into the reducer box to cool the gear. That is, the stator assembly oil pipe is formed by welding a straight pipe and a ring-shaped pipe, and the straight pipe is inserted into the gearbox shell to build an oil channel for lubricating the gearbox bearing in addition to cooling the stator.

[0057] According to another aspect of the present application, there is provided an electric drive system, the electric drive system comprising the electric drive system cooling structure as described above.

[0058] From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects: 1. The special structure design of the dynamic balance plate can realize two-way flow channel cooling of the rotor assembly internal core, thereby increasing the cooling area and improving the cooling efficiency; 2. The oil injection hole designed on the rotor shaft can guide the cooling oil into the core, and the dynamic balance plate internal flow channel is used to splash oil on the end of the stator winding; 3. The oil blocking structure provided on the rotary variable speed rotor pressure ring can realize bearing cooling. In order to facilitate the description, spatial relative terms such as "on", "above", "upper surface", "upper" and the like can be used to describe the spatial positional relationship of one device or feature with other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawings. For example, if the device in the drawing is inverted, the device described as "above" or "on" other devices or structures will be positioned "below" or "under" other devices or structures. Therefore, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated by 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0059] In addition to the above, it should be noted that "one embodiment", "another embodiment", "embodiment" and the like mentioned in the specification refer to specific features, structures or characteristics described in conjunction with the embodiment, which are included in at least one embodiment generally described in the present application. The same description appearing in several places in the specification does not necessarily refer to the same embodiment. Further, when a specific feature, structure or characteristic is described in conjunction with any embodiment, it is claimed that the implementation of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of the present application.

[0060] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0061] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. The present application can be variously changed and modified by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A cooling structure for an electric drive system, characterized in that, The electric drive system cooling structure includes a rotor assembly cooling structure, which includes: The rotor shaft (111) has an oil cavity (10) inside to contain oil. Two dynamic balancing plates (20) are provided, both of which are connected to the rotor shaft (111). The two dynamic balancing plates (20) are spaced apart along the axial direction of the rotor shaft (111). One of the two dynamic balancing plates (20) is provided with an oil inlet groove (410), and the other of the two dynamic balancing plates (20) is provided with an oil outlet groove (412). An oil sling hole (413) is provided at the end of the oil outlet groove (412) away from the rotor shaft (111) and passes through the dynamic balancing plate (20). The oil sling hole (413) is located close to the winding of the stator assembly. The oil inlet groove (410) is connected to the oil cavity (10). The rotor core assembly (30) is disposed between the two dynamic balance plates (20). The rotor core assembly (30) is connected to the rotor shaft (111). The rotor core assembly (30) is provided with a cooling oil passage (411). The two ends of the cooling oil passage (411) are respectively connected to the oil inlet groove (410) and the oil outlet groove (412). When the rotor shaft (111) rotates, some of the oil entering the cooling oil passage (411) can cool the inside of the rotor core assembly (30), and some of the oil can cool the windings of the stator assembly after being thrown out by the oil throwing hole (413). The rotor assembly cooling structure also includes: A rotor injection pipe (115) is disposed inside the rotor shaft (111). The rotor injection pipe (115) is provided with at least one oil outlet (1151). The rotor injection pipe (115) is connected to the oil chamber (10) through the oil outlet (1151) to perform cooling operation inside the oil chamber (10). The first end of the rotor shaft (111) along its own axis is connected to the rear end cover (303) of the electric drive system. The second end of the rotor shaft (111) along its own axis is connected to the transmission (105) of the electric drive system through a spline (113). The oil inlet end of the rotor injection pipe (115) is connected to the second end of the rotor shaft (111) through a connector (1152). The first end of the rotor shaft (111) is provided with a first bearing (407). The first bearing (407) and the connector (1152) form a first cooling chamber (1153). An oil guide end gasket (201) is provided, which is connected to the bearing hole of the rear end cover (303). The oil guide end gasket (201) is provided with a rotor oil inlet (202) located in the middle and a bearing oil inlet (203) located at the edge. The rotor oil inlet (202) is connected to the oil inlet end of the rotor oil injection pipe (115). The bearing oil inlet (203) is connected to the first cooling chamber (1153) so that the oil can perform cooling operation on the first bearing (407).

2. The cooling structure for the electric drive system according to claim 1, characterized in that, The dynamic balancing plate (20) includes a first dynamic balancing plate (402) and a second dynamic balancing plate (403) respectively disposed at both ends of the outer side wall of the oil chamber (10). The first dynamic balancing plate (402) is connected to the rotor shaft (111). The first dynamic balancing plate (402) has a plurality of oil inlet grooves (410) spaced apart along its circumference and a plurality of oil outlet grooves (412) spaced apart along its circumference. The second dynamic balancing plate (403) is disposed opposite to the first dynamic balancing plate (402) along the axial direction of the rotor shaft (111). The dynamic balancing plate (403) is configured with the same structure as the first dynamic balancing plate (402). The first dynamic balancing plate (402) and the second dynamic balancing plate (403) are installed on the rotor shaft (111) at a preset angle offset, so that each of the oil inlet grooves (410) of the first dynamic balancing plate (402) and each of the oil outlet grooves (412) of the second dynamic balancing plate (403) are configured in a one-to-one correspondence.

3. The cooling structure for the electric drive system according to claim 2, characterized in that, The rotor core assembly (30) includes multiple magnetic steel sheets (401) stacked between the first dynamic balancing plate (402) and the second dynamic balancing plate (403). Each magnetic steel sheet (401) has the same structure, and each magnetic steel sheet (401) has multiple guide holes (4010) arranged circumferentially. The stacked arrangement of the multiple magnetic steel sheets (401) allows the multiple coaxially arranged guide holes (4010) on different magnetic steel sheets (401) to form the... The cooling oil passage (411) consists of multiple passages. The two ends of a portion of the cooling oil passage (411) are connected to the oil inlet groove (410) of the first dynamic balance plate (402) and the oil outlet groove (412) of the second dynamic balance plate (403), respectively. The two ends of the other portion of the cooling oil passage (411) are connected to the oil inlet groove (410) of the second dynamic balance plate (403) and the oil outlet groove (412) of the first dynamic balance plate (402), respectively.

4. The cooling structure for the electric drive system according to claim 2, characterized in that, A second bearing (406) is provided at the second end of the rotor shaft (111), and a resolver rotor pressure ring (404) is provided at the second end of the rotor shaft (111). The resolver rotor pressure ring (404) is arranged adjacent to the second bearing (406). The resolver rotor pressure ring (404) has an oil baffle structure (4041) facing the second bearing (406). The oil baffle structure (4041), the second bearing (406), and part of the sidewall of the rotor shaft (111) form a second cooling cavity (4042). A first oil-blocking hole (4043) is provided inside the rotor shaft (111). The first oil-blocking hole (4043) is connected to the second cooling cavity (4042). Part of the oil in the rotor oil injection pipe (115) can enter the second cooling cavity (4042) through the first oil-blocking hole (4043) to cool the second bearing (406).

5. The cooling structure for the electric drive system according to claim 2, characterized in that, A bowl-shaped plug (112) is provided inside the second end of the rotor shaft (111), and a spline (113) is provided on the outer side wall of the second end of the rotor shaft (111). The rotor shaft (111) is connected to the transmission (105) through the spline (113). A second oil hole (1111) is provided inside the rotor shaft (111). An output shaft seal (114) is provided on the outer side wall of the second end of the rotor shaft (111) near the spline (113). The output shaft seal (114), the spline (113), and part of the outer side wall of the rotor shaft (111) form a third cooling chamber (1112). The third cooling chamber (1112) is connected to the second oil hole (1111). Part of the oil in the rotor oil injection pipe (115) can enter the third cooling chamber (1112) through the second oil hole (1111) to cool the spline (113).

6. The cooling structure for the electric drive system according to claim 3, characterized in that, Multiple third-section oil holes (409) are provided at both ends of the oil chamber (10) of the rotor shaft (111). The oil chamber (10) is connected to each of the oil inlet grooves (410) of the first dynamic balance plate (402) through a portion of the third-section oil holes (409). The oil chamber (10) is connected to each of the oil inlet grooves (410) of the second dynamic balance plate (403) through another portion of the third-section oil holes (409).

7. The cooling structure for the electric drive system according to claim 2, characterized in that, The rotor assembly cooling structure is disposed on the rotor assembly of the generator of the electric drive system, and the rotor assembly cooling structure is connected to the generator stator assembly (101), and / or, the rotor assembly cooling structure is disposed on the rotor assembly of the drive motor of the electric drive system, and the rotor assembly cooling structure is connected to the drive motor stator assembly (103).

8. The cooling structure for the electric drive system according to claim 2, characterized in that, The electric drive system cooling structure also includes a stator cooling assembly structure, which includes a generator stator oil injection pipe (301) and a drive motor stator oil injection pipe (302). At least one of the generator stator oil injection pipe (301) and the drive motor stator oil injection pipe (302) includes a bypass oil passage that extends into the housing of the transmission (105) to cool the transmission end bearing.

9. An electric drive system, the electric drive system comprising an electric drive system cooling structure, characterized in that, The electric drive system cooling structure is the electric drive system cooling structure as described in any one of claims 1 to 8.

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