Bidirectional double-layer oil cooling driving motor, power assembly and electric vehicle

Abstract

The embodiment of the invention provides a bidirectional double-layer oil cooling driving motor, a power assembly and an electric vehicle, and a stator iron core of a stator comprises a first iron core, a second iron core and a third iron core. The distance between each first-layer axial flow channel of the first iron core and a center hole of the stator iron core is larger than the distance between each second-layer axial flow channel and a center hole of one first iron core, the second iron core comprises a plurality of sets of bidirectional radial flow channels, and the radial flow channels in each set of bidirectional radial flow channels comprise a plurality of first radial flow channels and a plurality of second radial flow channels. The flow direction of the cooling oil in each first radial flow channel is opposite to that of the cooling oil in each second radial flow channel; each first radial flow channel is used for communicating with one first-layer axial flow channel and one second-layer axial flow channel, and each second radial flow channel is used for communicating with the other second-layer axial flow channel and one or more oil injection flow channels. The stator can realize oil cooling at the two ends without increasing the oil quantity, and the problems of small oil quantity, low oil pressure and difficult spraying are avoided.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and in particular to a bidirectional double-layer oil-cooled drive motor, a power assembly and an electric vehicle. Background Art

[0002] With the rapid development of new energy vehicles, the performance of the drive motor is crucial to the operation of the whole vehicle, and the performance requirements for the drive motor are also increasing day by day. The motor consists of a rotor and a stator. The stator generates a magnetic field to drive the rotor to rotate and output power. The iron loss and copper loss of the stator will increase the heat of the drive motor and affect the performance of the drive motor.

[0003] In the prior art, cooling oil can be introduced into the motor stator for oil cooling and heat dissipation, but there is still room for improvement in the oil cooling and heat dissipation method. Summary of the invention

[0004] The present application provides a bidirectional double-layer oil-cooled drive motor, powertrain and electric vehicle. The double-layer oil circuit can ensure a larger cooling area for the stator. The oil cooling circuit included in the stator of the drive motor can avoid the problems of low oil pressure, difficult oil injection and uneven oil distribution, thereby improving the cooling effect of the stator and the efficiency of the drive motor.

[0005] In a first aspect, an embodiment of the present application provides a bidirectional double-layer oil-cooled drive motor, wherein the housing of the drive motor is used to accommodate and fix the stator core of the drive motor, wherein the stator core comprises a first core, a second core and a third core, wherein a second core is arranged between a first core and a third core along the axial direction of the drive motor, wherein: a first core comprises a plurality of first-layer axial flow channels and a plurality of second-layer axial flow channels, a distance between each first-layer axial flow channel and a central hole of the stator core is greater than a distance between each second-layer axial flow channel and a central hole of a first core, a plurality of first-layer axial flow channels are distributed around the central hole of a second core, and a plurality of second-layer axial flow channels are distributed around the central hole of a second core; A second core includes multiple groups of bidirectional radial flow channels, which are distributed around the central hole of the second core, each group of bidirectional radial flow channels includes multiple radial flow channels, and the multiple radial flow channels of each group of bidirectional radial flow channels are arranged in sequence along the circumference of the second core, and the multiple radial flow channels in each group of bidirectional radial flow channels include multiple first radial flow channels and multiple second radial flow channels, and the flow direction of the cooling oil in each first radial flow channel is opposite to the flow direction of the cooling oil in each second radial flow channel; a third core includes multiple oil injection flow channels, each first radial flow channel is used to connect a first-layer axial flow channel and a second-layer axial flow channel respectively, and each second radial flow channel is used to connect another second-layer axial flow channel and one or more oil injection flow channels.

[0006] In the above-mentioned drive motor, each first-layer axial flow channel can form a circulation loop through a first radial flow channel, two interconnected second-layer axial flow channels, a second radial flow channel, and one or more oil injection flow channels. The circulation loop connects the inner and outer oil paths of the stator core in series, and finally sprays the cooling oil out of an axial end face of the stator core, so as to spray oil and cool the end winding of the drive motor. The flow direction of the cooling oil in each first radial flow channel is opposite to the flow direction of the cooling oil in each second radial flow channel, so that the cooling oil has different flow directions in the stator, which helps to realize the two-way oil injection of the stator. The flow channels in each circulation loop are connected in series to ensure that the oil pressure of the cooling oil remains consistent in the loop, and can also avoid the problem of small oil volume and low oil pressure that is difficult to spray.

[0007] In one embodiment, the stator core further comprises another first core, and the other first core and the first core are arranged adjacently along the axial direction of the drive motor, wherein: the other first core and the first core are arranged staggered along the circumferential direction of the drive motor, and the multiple first-layer axial flow channels of one first core and the multiple first-layer axial flow channels of the other first core are arranged staggered along the circumferential direction of the drive motor; the housing of the drive motor comprises an oil inlet hole, and the oil inlet hole is used to deliver cooling oil to the multiple first-layer axial flow channels of one first core and the multiple first-layer axial flow channels of the second core, and the flow direction of the cooling oil in the multiple first-layer axial flow channels of one first core is opposite to the flow direction of the cooling oil in the multiple first-layer axial flow channels of the other first core. The multiple first-layer axial flow channels of the two first cores are staggered to form a bidirectional oil path that is not connected along the axial direction of the drive motor, and the cooling oil received by the multiple first-layer axial flow channels included in each of the two first cores can flow to the two ends of the stator core respectively. The cooling oil in each first-layer axial flow channel flows along the axial direction of the drive motor for a shorter distance, and the oil resistance is smaller. By connecting the double-layer flow channel of the first core through the radial flow channel of the second core, the end plates at both ends of the stator core can be omitted, which is beneficial to reducing the weight of the drive motor and improving the heat dissipation effect inside the stator core, which is beneficial to improving the performance of the drive motor.

[0008] In one embodiment, the stator core further includes another second core and another third core, and the other second core is arranged between the other first core and the other third core along the axial direction of the drive motor, and the multiple second-layer axial flow channels of a first core are connected one-to-one with the multiple second-layer axial flow channels of another first core along the axial direction of the drive motor, wherein: a first radial flow channel of a second core is connected with a second radial flow channel of another second core through a second-layer axial flow channel of a first core and a second-layer axial flow channel of another first core along the axial direction of the drive motor. The combined structure of the three cores is used to realize the heat dissipation of the stator core by double-layer bidirectional flow channels, and the structure of the bidirectional axial flow channels in the stator core is simplified, which is not only conducive to improving the structural stability of the stator core, but also conducive to reducing the manufacturing cost of the drive motor.

[0009] In one embodiment, each first core includes a plurality of first punches, and the plurality of first punches in each first core are arranged in sequence along the axial direction of the first core, and each first punch includes a plurality of groups of cooling grooves and a plurality of cooling through holes, and the plurality of groups of cooling grooves surround the outer circumferential surface of the first punch along the circumference of the drive motor, and each group of cooling grooves includes a plurality of cooling grooves, and the recessed direction of each cooling groove faces the center hole of the first punch, and the plurality of cooling through holes are spaced around the center hole of the first punch along the circumference of the drive motor, and each cooling through hole and each cooling groove penetrate the first punch along the axial direction of the drive motor, wherein: the number of cooling grooves in each first core is less than the number of cooling through holes, and the plurality of cooling grooves of a first punch in each first core are respectively connected one-to-one along the axial direction of the drive motor to the plurality of cooling grooves of another adjacent first punch to form a plurality of first-layer axial flow channels, and the plurality of cooling through holes of each first punch in the stator core are respectively connected one-to-one along the axial direction of the stator core to the plurality of cooling through holes of another adjacent first punch to form a plurality of second-layer axial flow channels.

[0010] In one embodiment, the number of cooling grooves in each first core is equal to half the number of cooling holes, and the width of the cooling hole in each first punch is smaller than the width of each cooling groove along the circumference of the first punch, wherein: a plurality of cooling grooves are unevenly spaced around the center hole of the first punch, and a plurality of cooling holes are evenly spaced around the center hole of the first punch. When two first cores are arranged adjacently, the plurality of first-layer cooling oil channels formed by the plurality of first punches included in one first core can be circumferentially offset with the plurality of first-layer cooling oil channels formed by the plurality of first punches included in another first core, and the cooling oil received by the two first cores can be transported to the two ends of the stator core along the axial direction of the drive motor. The plurality of first-layer axial flow channels included in the two first cores are isolated from each other, and the plurality of second-layer axial flow channels included in the two first cores are connected, simplifying the structure of the double-layer bidirectional flow channels of the stator core.

[0011] In one embodiment, each cooling groove includes two sub-grooves, and the interval between the two sub-grooves in each cooling groove along the circumference of the first punch is smaller than the groove width of each sub-groove, wherein: the interval between the two sub-grooves in each cooling groove along the circumference of the first punch is the same, and the interval between two adjacent cooling grooves along the circumference of the first punch is larger than the interval between the two sub-grooves in each cooling groove, ensuring that each cooling groove can be connected to a radial flow channel.

[0012] In one embodiment, each group of cooling grooves includes four cooling grooves, and the four cooling grooves include a first cooling groove, a second cooling groove, a third cooling groove, and a fourth cooling groove, wherein: the first cooling groove, the second cooling groove, the third cooling groove, and the fourth cooling groove are arranged in sequence along the circumference of the first punching plate, the interval between the second cooling groove and the third cooling groove along the circumference of the first punching plate is smaller than the interval between the first cooling groove and the second cooling groove along the circumference of the first punching plate, the interval between the second cooling groove and the third cooling groove along the circumference of the first punching plate is smaller than the interval between the third cooling groove and the fourth cooling groove along the circumference of the first punching plate, and the interval between the third cooling groove and the fourth cooling groove along the circumference of the first punching plate is equal to the interval between the first cooling groove and the second cooling groove along the circumference of the first punching plate. Four cooling grooves form a group of cooling grooves, and the four cooling grooves meet the above arrangement rules, so that the multiple first-layer cooling oil channels formed by the multiple first punching plates included in one first iron core can be circumferentially misaligned with the multiple first-layer cooling oil channels formed by the multiple first punching plates included in another first iron core. The first cooling groove, the second cooling groove, the third cooling groove and the fourth cooling groove are distributed in an axisymmetric manner, and any two groups of adjacent cooling grooves are also distributed in an axisymmetric manner.

[0013] In one embodiment, the outer peripheral surface of the first punching sheet also includes a plurality of marking grooves, and the plurality of marking grooves surround the center hole of the first punching sheet. The plurality of marking grooves of each first punching sheet in the stator core are aligned one-to-one with the plurality of marking grooves of another adjacent first punching sheet along the axial direction of the drive motor, wherein: one of the two marking grooves adjacent along the circumference of the first punching sheet is used to separate two adjacent cooling grooves, and the other of the two marking grooves adjacent along the circumference of the first punching sheet is used to separate the second cooling groove and the third cooling groove in the same group of cooling grooves. The marking groove can be welded and fixed to the housing of the drive motor as a welding point of the first punching sheet, and the plurality of first punching sheets included in a first core are marked according to the distribution law of the plurality of marking grooves 1 and the plurality of cooling grooves, which can facilitate the alignment and assembly of the plurality of first punching sheets included in the first core. The plurality of first punching sheets included in the first core are marked with a plurality of marking grooves, which facilitates the alignment of the first layer axial flow channel and the second layer axial flow channel of the two first cores during the circumferential staggered arrangement, and is also conducive to simplifying the manufacturing process of the first punching sheet.

[0014] In one embodiment, each second core includes one or more second punching sheets, and the one or more second punching sheets are sequentially arranged between a first core and a third core along the axial direction of the drive motor. Each second punching sheet includes multiple groups of oil storage grooves, and the multiple groups of oil storage grooves are distributed around the central hole of the second punching sheet along the circumference of the drive motor. Each group of oil storage grooves includes multiple oil storage grooves, wherein: the shapes of two adjacent oil storage grooves along the circumference of the drive motor are different, and the shapes of two groove walls of each oil storage groove opposite to each other along the circumference of the second punching sheet are different. The flow directions of the cooling oil in the multiple oil storage grooves in the one or more second punching sheets included in the second core cooperate with each other to form multiple groups of bidirectional radial flow channels along the circumference of the stator core, further improving the heat dissipation balance of the stator core, thereby facilitating improving the performance of the drive motor.

[0015] In one embodiment, the slot opening of each oil storage groove is away from the center hole of the second punch along the radial direction of the second punch, the slot bottom of each oil storage groove is toward the center hole of the second punch along the radial direction of the second punch, and the length of each oil storage groove along the radial direction of the second punch is greater than the interval between each cooling hole in each first punch and the outer peripheral surface of the first punch, so that each oil storage groove can be connected to a cooling hole.

[0016] In one embodiment, the number of oil storage tanks used as the first radial flow channels in each group of oil storage tanks is the same as the number of oil storage tanks used as the second radial flow channels. The cooling oil is evenly distributed in the radial bidirectional flow of the drive motor in the second core, which can improve the heat dissipation balance of the stator core, thereby facilitating the improvement of the performance of the drive motor.

[0017] In one embodiment, each group of oil storage tanks includes eight oil storage tanks, four of the eight oil storage tanks in each group of oil storage tanks are used as four first radial flow channels, and the other four of the eight oil storage tanks in each group of oil storage tanks are used as four second radial flow channels, wherein: along the circumference of the second punching sheet, two of the four oil storage tanks as the first radial flow channels are adjacently arranged between the two oil storage tanks as the second radial flow channels, and the other two of the four oil storage tanks as the first radial flow channels are arranged between the two oil storage tanks of the second radial flow channels. The heat dissipation balance of the stator core is further improved, which is conducive to improving the performance of the drive motor.

[0018] In one embodiment, each third iron core includes a plurality of third punching sheets, each third punching sheet includes a plurality of pairs of oil outlet holes, the plurality of pairs of oil outlet holes are distributed around the central hole of the third punching sheet, and the interval between two pairs of oil outlet holes adjacent to each other along the circumference of the drive motor is greater than the interval between two oil outlet holes in each pair of oil outlet holes. This structural design is conducive to the oil outlet holes circumferentially avoiding the first layer of axial flow channels, facilitating the structural design of the first radial flow channel connecting the first layer of axial flow channels with the second layer of axial flow channels, and the structural design of the second radial flow channel connecting the injection oil channel with the second layer of axial flow channels.

[0019] In one embodiment, a plurality of third punching sheets in each third core are arranged adjacent to each other in the axial direction of the driving motor, a plurality of third punching sheets in each third core are arranged in a staggered manner in the circumferential direction of the driving motor, at least one oil outlet hole in each pair of oil outlet holes in each third punching sheet is used to connect to an oil outlet hole in another adjacent third punching sheet to form an oil injection flow channel; a third punching sheet in each third core and a second punching sheet in a second core are arranged adjacent to each other in the axial direction of the driving motor, each oil storage tank in the second punching sheet used to connect to the oil injection flow channel is used to connect to one oil outlet hole in a pair of oil outlet holes in a third punching sheet, and the other oil outlet hole in a pair of oil outlet holes is blocked by the second punching sheet. Each pair of two oil injection holes is used to connect to the oil injection according to demand, which is beneficial to the structural design of the third core and the second core.

[0020] In one embodiment, along the radial direction of the drive motor, the distance between each oil injection hole and the axis of the drive motor is smaller than the distance between each axial flow channel and the axis of the drive motor, thereby preventing the oil injection hole from connecting with the axial flow channel to form a parallel oil path.

[0021] In one embodiment, along the radial direction of the drive motor, the distance between each oil injection hole of a third punching plate and the axis of the drive motor is smaller than the distance between an oil injection hole of another third punching plate and the axis of the drive motor. The cooling oil can be sprayed obliquely in a direction close to the axis of the drive motor, thereby achieving more precise oil injection into the stator winding and achieving better cooling effect.

[0022] In a second aspect, the present application provides a power assembly, the power assembly includes a drive motor and a reducer, and the rotor shaft of the rotor is drivingly connected to the reducer. Since the motor has good heat dissipation performance, the heat dissipation performance and power performance of the power assembly can be improved.

[0023] In a third aspect, the present application provides an electric vehicle, the electric vehicle comprising wheels and a powertrain as provided in the second aspect, wherein a power output end of the powertrain is connected to the wheels through a transmission mechanism. The powertrain drives the wheels through a transmission mechanism. The electric vehicle provided by the present application has good heat dissipation performance and power performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of an electric vehicle provided in an embodiment of the present application;

[0025] Figure 2 A schematic diagram of the structure of a powertrain provided in an embodiment of the present application;

[0026] Figure 3 A schematic cross-sectional structure diagram of a drive motor provided in an embodiment of the present application;

[0027] Figure 4A schematic structural diagram of a stator of a drive motor provided in an embodiment of the present application;

[0028] Figure 5a A schematic diagram of a partial structure of a stator core of a drive motor provided in an embodiment of the present application;

[0029] Figure 5b An exploded view of a portion of the structure of a stator core of a drive motor provided in an embodiment of the present application;

[0030] Figure 6a A schematic diagram of a partial oil cooling circuit of a stator core of a drive motor provided in an embodiment of the present application;

[0031] Figure 6b A schematic diagram of a partial oil cooling circuit of a stator core of a drive motor provided in an embodiment of the present application;

[0032] Figure 7 A schematic diagram of a partial oil cooling circuit of a stator core of a drive motor provided in an embodiment of the present application;

[0033] Figure 8 A schematic structural diagram of two first cores of a stator core of a drive motor provided in an embodiment of the present application;

[0034] Figure 9a A schematic structural diagram of a stator core of a drive motor provided in an embodiment of the present application;

[0035] Figure 9b An exploded diagram of a stator core of a drive motor provided in an embodiment of the present application;

[0036] Fig.10a A schematic diagram of a partial oil cooling circuit of a stator core of a drive motor provided in an embodiment of the present application;

[0037] Fig.10b A schematic diagram of a partial oil cooling circuit of a stator core of a drive motor provided in an embodiment of the present application;

[0038] Fig.11 A schematic diagram of a partial oil cooling circuit of a stator core of a drive motor provided in an embodiment of the present application;

[0039] Fig.12a A schematic diagram of the structure of an oil cooling circuit of a drive motor provided in an embodiment of the present application;

[0040] Figure 12b A schematic diagram of the structure of an oil cooling circuit of a drive motor provided in an embodiment of the present application;

[0041] Fig.13aA schematic diagram of the structure of a first punching sheet of a driving motor provided in an embodiment of the present application;

[0042] Fig.13b A schematic diagram of a partial structure of a first punching sheet of a drive motor provided in an embodiment of the present application;

[0043] Fig.14 A schematic diagram of a partial structure of a stator of a drive motor provided in an embodiment of the present application;

[0044] Fig.15a A schematic diagram of the structure of a second punching plate of a drive motor provided in an embodiment of the present application;

[0045] Fig.15b A schematic diagram of the structure of a second punching plate of a drive motor provided in an embodiment of the present application;

[0046] Fig.16 A schematic diagram of a partial structure of a stator of a drive motor provided in an embodiment of the present application;

[0047] Fig.17 A schematic diagram of a partial structure of a stator of a drive motor provided in an embodiment of the present application;

[0048] Fig.18 A schematic diagram of the structure of a third punching plate of a drive motor provided in an embodiment of the present application;

[0049] Fig.19 A schematic diagram of a partial structure of a stator of a drive motor provided in an embodiment of the present application;

[0050] Fig. 20 A schematic cross-sectional view of a portion of the structure of a stator core of a drive motor provided in an embodiment of the present application;

[0051] Fig.21 A schematic diagram of a partial structure of a stator core of a drive motor provided in an embodiment of the present application;

[0052] Fig.22a A schematic diagram of the structure of two third punching sheets of a driving motor provided in an embodiment of the present application;

[0053] Figure 22b A schematic diagram of the structure of a plurality of third punching sheets of a drive motor provided in an embodiment of the present application;

[0054] Fig.23 A schematic diagram of the structure of two third punching sheets of a driving motor provided in an embodiment of the present application;

[0055] Fig.24a A schematic cross-sectional view of a portion of the structure of a stator core of a drive motor provided in an embodiment of the present application;

[0056] Figure 24b A schematic diagram of the cross-sectional structure of multiple third punching sheets of a drive motor provided in an embodiment of the present application;

[0057] Fig.25 A schematic diagram of the structure of multiple third punching sheets of a drive motor provided in an embodiment of the present application.

[0058] Reference numerals:

[0059] 1000-powertrain; 2000-transmission mechanism; 3000-wheel;

[0060] 100-motor; 200-motor controller; 300-reducer;

[0061] 10-stator; 1-stator core; 101-first core; 102-second core; 103-third core; 2-stator winding; 20-rotor; 30-housing; 301-annular flow channel;

[0062] 11, 11i, 11j-first punch; 111, 111i, 111j-cooling through hole; 112, 112i, 112j-cooling groove; 112a-first cooling groove; 112b-second cooling groove; 112c-third cooling groove; 112d-fourth cooling groove; 1121-sub-groove; 113, 113m, 113n, 113i, 113j-marking groove; 12, 12i, 12j-second punch; 121, 121m, 121n, 121i, 121j-oil storage tank; 13, 13i, 13j-third punch; 131, 131i, 131j, 131m, 131n, 131p, 131q, 131w, 131v-oil outlet hole;

[0063] a, a1, a2-axial end face; c-groove; d11-first layer axial flow channel; d12-second layer axial flow channel; d2-radial flow channel; d21-first radial oil channel; d22-second radial oil channel; d3-injection oil channel; d31-straight flow channel; d32-oblique flow channel; j-oil inlet; k-center through hole; K, k, k1, k2, k3-center hole; Z-winding slot. DETAILED DESCRIPTION

[0064] The drive motor is an important part of the powertrain of electric vehicles. With the vigorous development of the electric vehicle industry, the requirements for the performance of the drive motor are also increasing day by day. There is a strong coupling between the performance improvement of the drive motor and the thermal risk: on the one hand, with the increase of speed, current density, and power density, the iron loss and copper loss of the motor stator will cause the heat to increase, and the stator coil, especially the winding in the stator core, will have the risk of overheating; on the other hand, improving the heat dissipation capacity of the stator core can bring room for improvement of motor performance, which is conducive to increasing motor power, improving motor efficiency, and reducing risks such as demagnetization. Therefore, efficient heat dissipation of the drive motor is an important measure to enhance the endurance and safety of electric vehicles.

[0065] In traditional technology, oil cooling is generally used to dissipate heat from the stator of the motor. In current oil-cooled motors, the oil cooling effect of the stator core with a single-layer oil circuit is poor, and the oil passing through the stator core slot requires high sealing. In the cooling method of forming a double-layer oil circuit in the stator core and spraying oil at both ends, the oil pressure, oil volume, oil resistance and other issues need to be considered in the oil circuit design, and the cooling effect is not ideal.

[0066] Based on this, the embodiments of the present application provide a bidirectional double-layer oil-cooled drive motor, powertrain and electric vehicle. The double-layer oil circuit can ensure a larger cooling area for the stator. The bidirectional oil circuit can avoid the problems of low oil pressure, difficult oil injection and uneven oil distribution, and can improve the cooling effect and efficiency of the drive motor.

[0067] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings.

[0068] Figure 1 A schematic diagram of the structure of an electric vehicle provided in an embodiment of the present application is shown in FIG. Figure 1As shown, the electric vehicle is a wheeled device driven or towed by a power device, and can be specifically a pure electric vehicle (pure electric vehicle / battery electric vehicle, pure EV / battery EV), a hybrid electric vehicle (hybrid electric vehicle, HEV), a range extended electric vehicle (range extended electric vehicle, REEV) or a plug-in hybrid electric vehicle (plug-in hybrid electric vehicle, PHEV), etc. The electric vehicle includes a powertrain 1000, a transmission mechanism 2000 and a wheel 3000. The powertrain 1000 drives the wheel 3000 through the transmission mechanism 2000. Among them, the powertrain 1000 is used to convert electrical energy into mechanical energy. The transmission mechanism 2000 is used to transmit and connect the powertrain 1000 and the wheel 3000. Of course, the electric vehicle also includes a frame that withstands the internal and external environmental loads of the vehicle and a battery for supplying power to the powertrain 1000.

[0069] Figure 2 This is a schematic diagram of the structure of the powertrain 1000 provided in the embodiment of the present application. Figure 2 As shown, the powertrain 1000 includes a drive motor 100 and a motor controller 200. The motor controller 200 is used to convert the direct current provided by the battery into alternating current, and transmit the alternating current to the drive motor 100. In one embodiment, the powertrain 1000 also includes a reducer 300, and the power output end of the drive motor 100 is connected to the wheel 3000 of the vehicle through the reducer 300. In some embodiments, the reducer 300 is replaced by a transmission. Among them, the drive motor 100 of the electric vehicle is generally a permanent magnet synchronous or AC asynchronous motor.

[0070] Figure 3 FIG. 1 is a schematic cross-sectional view of a drive motor 100, which is a bidirectional double-layer oil-cooled drive motor. Figure 3 As shown, the drive motor 100 includes a stator 10, a rotor 20 and a housing 30, and a portion of the stator 10 and the rotor 20 are accommodated in the housing 30. One end of the rotor shaft of the rotor 20 extends out of the housing 30 to form a power output end S of the drive motor 100. The stator 10 is sleeved outside the rotor core 1, and the stator 10 includes a stator core 1 and a stator winding 2 wound around the stator core 1. When the stator winding 2 is energized, a magnetic field can be formed in the center of the stator core 1, and the rotor 20 can rotate around the axis of the rotor 20 in the magnetic field.

[0071] Please continue to refer to Figure 3As shown, in one embodiment, the outer circumference of the stator core 1 is fixed to the inner wall of the housing 30, and the housing 30 includes an oil inlet j for supplying oil to the stator core 1. The interior of the stator core 1 includes an oil cooling circuit for circulating cooling oil, and the oil inlet j supplies the cooling oil to the oil cooling circuit of the stator core 1 through the outer circumference of the stator core 1. The oil cooling circuit of the stator core 1 guides the cooling oil to the two ends of the stator core 1 along the axial direction of the drive motor to spray and cool the stator winding 2.

[0072] In the embodiment of the present application, the axial direction of the drive motor, the axial direction of the stator, the axial direction of the stator core, and the axial direction of the rotor refer to the same direction, the circumferential direction of the stator, the circumferential direction of the stator core, the circumferential direction of the drive motor, and the circumferential direction of the rotor refer to the same direction, and the radial direction of the stator, the radial direction of the stator core, the radial direction of the drive motor, and the radial direction of the rotor refer to the same direction. For ease of understanding, taking the drive motor 100 as an example, the axial direction of the drive motor is represented by the letter A, the radial direction of the drive motor is represented by the letter R, and the circumferential direction of the drive motor is represented by the letter C.

[0073] In one embodiment, Figure 4 As shown, a stator 10 provided in an embodiment of the present application includes a stator core 1 and a stator winding 2, wherein the stator core 1 includes a central hole K for accommodating a rotor 20. Along the axial direction of the drive motor, the stator core 1 includes two axial end faces a, the stator winding 2 is wound on the stator core 1, and two ends of the stator winding 2 extend out of the two axial end faces a of the stator core 1, respectively.

[0074] In one embodiment, the outer peripheral surface of the stator core 1 is used to receive the cooling oil provided by the shell 30 and supply it to the two axial end faces a of the stator core 1 through an internal oil cooling circuit. The cooling oil can be sprayed out of the two axial end faces a to perform oil cooling and heat dissipation on the ends of the stator winding 2 that expose the two axial end faces a.

[0075] Figure 5a This is a partial structural diagram of the stator core 1 provided in the embodiment of the present application. Figure 5a As shown, along the axial direction of the driving motor, the stator core 1 includes a first core 101, a second core 102 and a third core 103. Along the axial direction of the driving motor, the second core 102 is adjacently arranged between the first core 101 and the third core 103. The end face of the third core 103 facing away from the second core 102 is an axial end face a of the stator core 1. The stator core 1 includes a center hole K and a plurality of winding slots Z. The center hole K and the winding slots Z penetrate the stator core 1 along the axial direction of the driving motor. Each winding slot Z is connected to the center hole K along the radial direction of the driving motor. The plurality of winding slots Z are arranged at intervals along the circumferential direction of the driving motor. The stator winding 2 is wound around the plurality of winding slots Z of the stator core 1.

[0076] Figure 5b for Figure 5a The exploded view of the part of the stator core 1 shown. Figure 5a and Figure 5b As shown, the center hole k1 of the first core 101, the center hole k1 of the second core 102, and the center hole k3 of the third core 103 can be connected in sequence along the axial direction of the drive motor to form the center hole K of the stator 10. The inner diameters of the center hole k1 of the first core 101, the center hole k2 of the second core 102, and the center hole k3 of the third core 103 are the same, and the axes of the center hole k1 of the first core 101, the center hole k2 of the second core 102, and the center hole k3 of the third core 103 are collinear, and the axes of the first core 101, the second core 102, and the third core 103 are collinear. The axes of the first core 101, the second core 102, and the third core 103 are also the axes of the stator 10 and the axes of the drive motor 100.

[0077] like Figure 5b As shown, the first iron core 101 includes a first layer of axial flow channels d11 and a second layer of axial flow channels d12. The number of the first layer of axial flow channels d11 is multiple, and the number of the second layer of axial flow channels d12 is multiple. The multiple first layer of axial flow channels d11 are arranged in intervals around the center hole k1 of the first iron core 101 along the circumference of the drive motor, and the multiple second layer of axial flow channels d12 are arranged in intervals around the center hole k1 of the first iron core 101 along the circumference of the drive motor. In the radial direction of the drive motor, the spacing between the first layer of axial flow channels d11 and the axis of the stator 10 is greater than the spacing between each second layer of axial flow channels d12 and the axis of the stator 10. Taking the center hole k1 of the first iron core 101 as a reference, in the radial direction of the drive motor, the spacing between the first layer of axial flow channels d11 and the center hole k1 of the first iron core 101 is greater than the spacing between each second layer of axial flow channels d12 and the axis of the center hole k1 of the first iron core 101. Along the radial direction of the driving motor, a plurality of first-layer axial flow channels d11 constitute one layer of flow channels of the stator core 1, and a plurality of second-layer axial flow channels d12 constitute another layer of flow channels of the stator core 1. The first core 101 has two layers of oil channels distributed along the radial direction.

[0078] In one embodiment, each first-layer axial flow channel d11 penetrates the first core 101, and each first-layer axial flow channel d11 is connected to the first core

[0079] In one embodiment, each second-layer axial flow channel d12 penetrates the first iron core 101 , and each second-layer axial flow channel d11 communicates with two end surfaces of the first iron core 101 .

[0080] In one embodiment, each first-layer axial flow channel d11 penetrates the first iron core 101 along the axial direction of the drive motor, each first-layer axial flow channel d11 connects two end surfaces of the first iron core 101, and the extension direction of each first-layer axial flow channel d11 is parallel to the axial direction of the drive motor.

[0081] In one embodiment, each second-layer axial flow channel d12 penetrates the first iron core 101 along the axial direction of the driving motor and respectively penetrates the first iron core 101, each second-layer axial flow channel d12 connects the two end surfaces of the first iron core 101, and the extension direction of each second-layer axial flow channel d12 is parallel to the axial direction of the driving motor.

[0082] In one embodiment, the second core 102 includes a plurality of radial flow channels d2, which are arranged at intervals around the center hole k2 of the second core 102 along the circumference of the drive motor. The third core 103 includes a plurality of oil injection flow channels d3, which are arranged at intervals along the center hole k3 of the third core 103. Each oil injection flow channel d3 is connected to two end surfaces of the third core 103 along the axial direction of the drive motor.

[0083] In one embodiment, along the radial direction of the drive motor, each first-layer axial flow channel d11 of the first core 101 is connected to the outer peripheral surface of the first core 101 and can be used to receive cooling oil delivered by the housing 30 .

[0084] In one embodiment, along the radial direction of the drive motor, each radial flow channel d2 of the second core 102 is connected to the outer peripheral surface of the second core 102. Each radial flow channel d2 is connected to two end surfaces of the second core 102.

[0085] In one embodiment, each radial flow channel d2 is connected to two end surfaces of the second core 102 along the axial direction of the driving motor, and the direction in which each radial flow channel d2 penetrates the second core 102 is parallel to the axial direction of the driving motor.

[0086] Figure 6a and Figure 6b The schematic cross-sectional diagrams of the partial structures of the stator core 1 are respectively shown. In one embodiment, the plurality of radial flow channels d2 included in the second core 102 are divided into a plurality of groups of bidirectional radial flow channels, and the plurality of groups of bidirectional radial flow channels are arranged in sequence along the circumference of the drive motor. The plurality of radial flow channels d2 included in each group of bidirectional radial flow channels include a plurality of first radial flow channels d21 and a plurality of second radial flow channels d22. Figure 6a The section plane in passes through a first layer axial flow channel d11, a first radial flow channel d21 and a second layer axial flow channel d12. Figure 6b The section plane in passes through a second-layer axial flow channel d12, a second radial flow channel d22 and an oil injection flow channel d3. Figure 6a The first radial flow channel d21 and Figure 6bThe second radial flow channels d22 in belong to the same group of bidirectional radial flow channels.

[0087] like Figure 6a As shown, taking a first radial flow channel d21 as an example, each first radial flow channel d21 is used to connect a first-layer axial flow channel d11 and a second-layer axial flow channel d12. The flow direction of the cooling oil in the first radial flow channel d21 is from the first-layer axial flow channel d11 to the second-layer axial flow channel d12 along the radial direction of the drive motor. The first radial flow channel d21 can connect the first-layer axial flow channel d11 and the second-layer axial flow channel d12 to achieve the connection of the double-layer oil channel of the stator core 1. The end plates at both ends of the stator core 1 can be omitted, which is beneficial to reduce the weight of the drive motor 100, and can also improve the heat dissipation effect inside the stator core 1, which is beneficial to improve the performance of the drive motor 100.

[0088] like Figure 6b As shown, taking a second radial flow channel d22 as an example, each first radial flow channel d21 is used to connect a second layer axial flow channel d12 and one or more oil injection flow channels d3. The flow direction of the cooling oil in the second radial flow channel d22 is from the second layer axial flow channel d12 to the one or more oil injection flow channels d3 along the radial direction of the drive motor. Each oil injection flow channel d3 is used to guide the cooling oil to the axial end of the stator core 1.

[0089] Combination Figure 6a and Figure 6b As shown, the flow direction of the cooling oil in the first radial flow channel d21 and the second radial flow channel d22 is opposite, so that the flow direction of the cooling oil in the second layer axial flow channel d12 connected to the first radial flow channel d21 is opposite to the flow direction of the cooling oil in the second layer axial flow channel d22 connected to the second radial flow channel d22, and the cooling oil can flow in both directions along the axial direction of the drive motor in the stator core 1, which helps to guide the cooling oil to both ends of the stator core 1. The flow directions of the cooling oil in each group of radial flow channels d2 in the second core 102 cooperate with each other to form multiple groups of bidirectional radial flow channels d2 along the circumference of the stator core 1, which can further improve the heat dissipation balance of the stator core 1, thereby helping to improve the performance of the drive motor 100.

[0090] Figure 7 FIG. 1 is a simplified schematic diagram of a partial structure of the internal oil cooling circuit of the stator core 1. Figure 7As shown, along the axial direction of the drive motor, the second core 102 is adjacently arranged between the first core 101 and the third core 103, and the end face of the third core 103 facing away from the second core 102 is an axial end face a of the stator core 1, and the oil injection channel d3 is connected to the axial end face a. Taking a first radial channel d21 and a second radial channel d22 in a set of bidirectional radial channels as an example, the first radial channel d21 connects a first-layer axial channel d11 with a second-layer axial channel d12, and the second radial channel d22 connects a second-layer axial channel d12 with an oil injection channel d3. The cooling oil flows in the first radial flow channel d21 and the second radial flow channel d22 in opposite directions, and the cooling oil flows in a second-layer axial flow channel d12 connected to the first radial flow channel d21 and the cooling oil flows in a second-layer axial flow channel d12 connected to the second radial flow channel d22 are opposite along the axial direction of the drive motor, thereby realizing a bidirectional flow of cooling oil in the oil cooling circuit inside the stator core 1.

[0091] In one embodiment, Figure 8 As shown, the stator core 1 includes two first cores 101, and one first core 101 and the other first core 101 are arranged adjacent to each other along the circumference of the drive motor. The one first core 101 and the other first core 101 are arranged staggered along the circumference of the drive motor, and the multiple first-layer axial flow channels d11 included in the one first core 101 and the multiple first-layer axial flow channels d11 included in the other first core 101 are arranged staggered along the circumference of the drive motor. The cooling oil delivered from the housing 30 of the motor 100 can be delivered to the multiple first-layer axial flow channels d11 of the one first core 101 and the multiple first-layer axial flow channels d11 of the other first core 101, respectively. The outer axial flow channels of the two first cores 101 are staggered and not connected.

[0092] In one embodiment, Figure 8 The plurality of second-layer axial flow passages d12 included in one first core 101 are connected in a one-to-one manner with the plurality of second-layer axial flow passages d12 included in another first core 101. The inner-layer axial flow passages of the two first cores 101 are connected.

[0093] based on Figure 8 The two first cores 101 shown in FIG. Figure 9a As shown, the stator core 1 further includes two second cores 102 and two third cores 103. Figure 9b FIG. 1 is an exploded view of the stator core 1 .

[0094] Refer to Figure 9a and Figure 9bAs shown, along the axial direction of the driving motor, a first iron core 101 and another first iron core 101 are arranged adjacent to each other along the axial direction of the driving motor, a second iron core 102 and a third iron core 103 are arranged in sequence on a side of a first iron core 101 away from another first iron core 101, and another second iron core 102 and another third iron core 103 are arranged in sequence on a side of another first iron core 101 away from one first iron core 101. The end face of each third iron core 103 on the side away from the adjacent second iron core 102 is an axial end face a of the stator iron core 1.

[0095] Fig.10a and Fig.10b The schematic cross-sectional diagrams of the stator core 1 are shown respectively. Figure 8 In the state shown, the second core 102 is arranged between the first core 101 and the third core 103, and the other second core 102 is arranged between the other first core 101 and the other third core 103. The end face of the third core 103 facing away from the second core 102 is the first end face a1, and the end face of the other third core 103 facing away from the other second core 102 is the second end face a2. The first end face a1 and the second end face a2 are the two end faces a of the stator core 1.

[0096] Refer to Fig.10a and Fig.10b As shown, a second core 102 is offset from another second core 102 along the circumferential direction of the drive motor, and each second-layer axial flow channel d12 of a first core 101 is connected to a second-layer axial flow channel d22 of another first core 101. A first radial flow channel d21 of a second core 102 is opposite to a second radial flow channel d22 of another second core 102 along the axial direction of the drive motor. Of the two connected second-layer axial flow channels d22, one second-layer axial flow channel d12 is connected to a first-layer axial flow channel d11 through a first radial flow channel d21, and the other second-layer axial flow channel d12 is connected to an injection flow channel d3 through a second radial flow channel d22.

[0097] by Fig.10aTaking a circulation circuit shown as an example, a first-layer axial flow channel d11 of a first iron core 101 on the left is connected to a second-layer axial flow channel d12 of the first iron core 101 on the left through a first radial oil channel d21 of a second iron core 102 on the left, a second-layer axial flow channel d12 of the first iron core 101 on the left is connected to a second-layer axial flow channel d12 of the first iron core 101 on the right, a second-layer axial flow channel d12 of the first iron core 101 on the right is connected to an injection oil channel d3 of the third iron core 103 on the right through a second radial oil channel d21 of a second iron core 102 on the right, and the injection oil channel d3 is connected to the second end face a2.

[0098] by Fig.10b Taking a circulation circuit shown as an example, a first-layer axial flow channel d11 of a first iron core 101 on the right side is connected to a second-layer axial flow channel d12 of the first iron core 101 on the right side through a first radial oil channel d21 of a second iron core 102 on the right side, a second-layer axial flow channel d12 of the first iron core 101 on the right side is connected to a second-layer axial flow channel d12 of the first iron core 101 on the left side, a second-layer axial flow channel d12 of the first iron core 101 on the left side is connected to an injection oil channel d3 of the third iron core 103 on the left side through a second radial oil channel d21 of a second iron core 102 on the left side, and the injection oil channel d3 is connected to the first end face a1.

[0099] Fig.11 It is a simplified schematic diagram of a part of the structure of the internal oil cooling circuit of the stator core 1. Fig.10a and Fig.10b ,like Fig.11 As shown, along the axial direction of the drive motor, each second core 102 is adjacently arranged between the first core 101 and the third core 103, and the end faces of the two third cores 103 facing away from the adjacent second cores 102 are respectively two axial end faces a of the stator core 1. A part of the cooling oil in the stator core 1 is sprayed out from the first end face a1, and a part is sprayed out from the second end face a2. Fig.11 Two flow loops are shown, one of which is similar to Fig.10a As shown, cooling oil is sprayed from the first end face a1, and another circulation circuit is similar to Fig.10b As shown, cooling oil is sprayed out from the second end face a2 to realize bidirectional flow of cooling oil in the oil cooling circuit inside the stator core 1.

[0100] Combined with the above Fig.10a , Fig.10b as well as Fig.11, the oil injection paths of the two axial end faces a of the stator core 1 are similar, but in different directions. The stator core 1 includes a plurality of circulation circuits, each of which includes a first-layer axial flow channel d11, a first radial flow channel d21, two second-layer axial flow channels d12, a second radial flow channel d22, and an oil injection flow channel d3 that are sequentially connected. In one embodiment, in each circulation circuit, the first-layer axial flow channel d11 and the second-layer axial flow channel d12 are arranged at intervals along the radial direction of the drive motor, the first-layer axial flow channel d11 is close to the outer peripheral surface of the stator core 1, and the second-layer axial flow channel d12 is close to the center hole K of the stator core 1. The first radial oil passage d21 and the second radial oil passage d22 are arranged opposite to each other along the axial direction of the drive motor, and the first radial oil passage d21 and the second radial oil passage d22 are respectively close to the two axial end faces of the stator core 1. Each circulation circuit connects the first-layer axial flow channel d11 and the second-layer axial flow channel d12 in series, and the cooling oil can maintain a relatively consistent oil pressure and oil volume during the circulation of any oil passage. When the amount of cooling oil remains unchanged, the cooling oil can be distributed to the multiple first-layer axial flow channels d11 included in each first core 101, wherein the cooling oil in the multiple first-layer axial flow channels d11 of one first core 101 and the cooling oil in the multiple first-layer axial flow channels d11 of another first core 101 respectively flow toward both ends of the stator 10. The cooling oil flowing in each first-layer axial flow channel d11 has a shorter distance along the axial direction of the drive motor, and the oil resistance is smaller.

[0101] Fig.12a and Figure 12b The schematic diagram of the scheme of liquid cooling the stator 10 by cooling oil is illustrated. The housing 30 is fixed to the outer peripheral surface of the stator core 1 along the circumference of the drive motor, and the stator winding 2 is wound on the stator core 1. The two ends of the stator winding 2 extend out of the two axial end surfaces a of the stator core 1 along the axial direction of the drive motor. The housing 30 includes an oil inlet j and an annular flow channel 301. The oil inlet j connects the outer peripheral surface and the inner peripheral surface of the housing 30. The annular flow channel 301 is an annular groove forming the inner peripheral surface of the housing 30. The oil inlet j is connected to the annular flow channel 301.

[0102] In one embodiment, the annular flow channel 301 is connected to each first-layer axial flow channel d11 of the stator core 1 along the radial direction of the drive motor, and the annular flow channel 301 can transport the cooling oil introduced by the oil inlet j along the circumferential direction of the drive motor to each first-layer axial flow channel d11 of the stator core 1. The first-layer axial flow channel d11 of each circulation circuit receives the cooling oil transported by the housing 30.

[0103] The stator core 1 provided in the embodiment of the present application includes two first cores 101, two second cores 102 and two third cores 103, which can form a plurality of Fig.11The circulation circuit shown. The two first cores 101 are staggered along the axial direction of the drive motor, so that the multiple first-layer axial flow channels d11 of the two first cores 101 are staggered to form a bidirectional oil path that is not connected along the axial direction of the drive motor. The cooling oil received by the multiple first-layer axial flow channels d11 included in each of the two first cores 101 can be transported to the two ends of the stator 10 through their respective circulation circuits, and oil cooling of the two ends of the stator 10 can be achieved without increasing the amount of oil.

[0104] In one embodiment, the two first cores 101 have the same length along the circumference of the drive motor, and the first layer of the axial flow channel d11 of each circulation circuit is half the axial length of the stator core 1. Along the axial direction of the drive motor, the annular flow channel 301 is located at the center of the stator core 1, and can evenly distribute the cooling oil to the two first cores 101.

[0105] by Fig.12a Taking a circulation circuit shown as an example, a first-layer axial flow channel d11 of a first iron core 101 on the left receives a portion of the cooling oil delivered by the shell 30, and the portion of the cooling oil flows in the first-layer axial flow channel d11 along the axial direction of the drive motor toward the first end face a1 of the stator iron core 1 and enters a first radial oil channel d21 of a second iron core 102 on the left, flows in the first radial oil channel d21 along the radial direction of the drive motor to a second-layer axial flow channel d12 of the first iron core 101 on the left, flows in the second-layer axial flow channel d12 along the axial direction of the drive motor to a second-layer axial flow channel d12 of the first iron core 101 on the right, then passes through a second radial oil channel d22 of a second iron core 102 on the right, enters an oil injection path d3 of the third iron core 103 on the right, and finally is sprayed out of the second end face a2 of the stator iron core 1 through the oil injection path d3.

[0106] by Figure 12b Taking a circulation circuit shown as an example, a first layer axial flow channel d11 of a first iron core 101 on the right receives a portion of the cooling oil delivered by the shell 30, and the portion of the cooling oil flows in the first layer axial flow channel d11 along the axial direction of the drive motor toward the second end face a2 of the stator iron core 1 and enters a first radial oil channel d21 of a second iron core 102 on the right, flows in the first radial oil channel d21 along the radial direction of the drive motor to a second layer axial flow channel d12 of the first iron core 101 on the right, flows in the second layer axial flow channel d12 along the axial direction of the drive motor to a second layer axial flow channel d12 of the first iron core 101 on the left, then passes through a second radial oil channel d22 of a second iron core 102 on the left, enters an oil injection path d3 of the third iron core 103 on the left, and finally is sprayed out of the first end face a1 of the stator iron core 1 through the oil injection path d3.

[0107] In one embodiment, the stator core 1 includes a plurality of the above-mentioned circulation circuits, a portion of the plurality of circulation circuits sprays oil from one of the axial end faces a of the stator core 1, and another portion of the plurality of circulation circuits sprays oil from another axial end face a of the stator core 1, so that the two end windings of the stator winding 2 can be sprayed with oil for cooling. The flow channels in each circulation circuit are connected in series, which can ensure that the oil pressure of the cooling oil remains consistent in the circuit. In each circulation circuit, the first radial flow channel d21 is connected between the first layer axial flow channel d11 and the second layer axial flow channel d12 to connect the inner and outer layers of the stator core 1 in series, and the second radial flow channel d22 is connected between the second layer axial flow channel d12 and the oil injection channel d3 to guide the internal oil channel to the end of the stator core 1. The series connection of each part of the oil channels in the circulation circuit can avoid the problem of small oil volume and low oil pressure that is difficult to spray.

[0108] In one embodiment, each first core 101 of the stator core 1 includes a plurality of Fig.13a The first punching sheets 11 shown, multiple first punching sheets 11 in each first core 101 are arranged in sequence along the axial direction of the drive motor. Each first punching sheet 11 includes a center hole k and multiple grooves c. The center hole k and each groove c penetrate the first punching sheet 11 along the axial direction of the drive motor. Each groove c is connected to the center hole k along the radial direction of the drive motor. Multiple grooves c are arranged at intervals along the circumferential direction of the drive motor. Multiple center holes k of multiple first punching sheets 11 are connected to form a part of the center hole K of the stator core 1, and multiple grooves c of multiple first punching sheets 11 are respectively connected to form a part of multiple winding slots Z of the stator core 1.

[0109] Please continue to refer to Fig.13a As shown, each first punching plate 11 includes multiple groups of cooling grooves 112 and multiple cooling through holes 111, each group of cooling grooves includes multiple cooling grooves 112, and each group of cooling grooves 112 is indicated by a dotted frame. Multiple cooling grooves 112 surround the outer peripheral surface distributed on the first punching plate 11, and the concave direction of each cooling groove 112 faces the central hole k of the first punching plate 11. Multiple cooling through holes 111 are distributed around the central hole k of the first punching plate 11 at intervals, and each cooling through hole 111 passes through the first punching plate 11.

[0110] In one embodiment, each cooling through hole 111 and each cooling groove 112 penetrate the first punching plate 11 along the axial direction of the driving motor, and multiple cooling through holes 111 are arranged at intervals along the circumferential direction of the driving motor, and multiple cooling grooves 112 are arranged at intervals along the circumferential direction of the driving motor. Each cooling groove 112 is connected to the outer peripheral surface of the first punching plate 11 along the radial direction of the driving motor, and the cooling groove 112 is used to receive the cooling oil transmitted from the housing 30. The cooling groove 112 and the cooling through hole 111 are both used to circulate the cooling oil. The structural design of the two-layer oil circuit of the first punching plate 11 can be realized along the radial direction of the driving motor, thereby increasing the oil cooling area of ​​the cooling oil and bringing about a better cooling effect. For the first punching plate 11, the manufacturing process of the cooling groove 112 and the cooling through hole 111 is also relatively simple and easy to implement.

[0111] In one embodiment, Fig.13a As shown, along the circumferential direction of the drive motor, each cooling through hole 111 is arranged between two grooves c. Along the radial direction of the drive motor, the distance between each cooling through hole 111 and the center hole k is smaller than the distance between the bottom of each groove c and the center hole k. Each groove c is used to accommodate the stator winding 2. The cooling oil passing through the cooling through hole 111 can exchange heat through the first punching sheet 11, take away the heat generated by the stator winding 2, and realize oil cooling of the stator 10.

[0112] In one embodiment, Fig.13a As shown, the multiple grooves c and the multiple cooling holes 111 included in each first punching sheet 11 are evenly distributed along the circumference of the drive motor, the number of the grooves c is the same as the number of the cooling holes 111, and each cooling hole 111 is arranged between two adjacent grooves c at intervals.

[0113] In one embodiment, in each first punching sheet 11, the number of cooling grooves 112 is less than the number of cooling through holes 111. In each first core 101, the multiple cooling grooves 112 of one first punching sheet 11 are connected one-to-one with the multiple cooling grooves 112 of another adjacent first punching sheet 11 along the axial direction of the drive motor to form a plurality of first-layer axial flow channels d11, and the multiple cooling through holes 111 of each first punching sheet 11 in the first core 101 are connected one-to-one with the multiple cooling through holes 111 of another adjacent first punching sheet 11 along the axial direction of the drive motor to form a plurality of second-layer axial flow channels d12.

[0114] For a first iron core 101, each cooling through hole 111 in a part of the cooling through holes 111 is used to connect to one cooling groove in a plurality of cooling grooves 112 through a first radial flow channel d21, and each cooling through hole 111 in another part of the cooling through holes 111 is used to connect to an oil injection channel through a second radial flow channel d22. In one embodiment, in each first iron core 101, the number of cooling grooves 112 is equal to half the number of cooling through holes 111, which is conducive to the cooling oil in different directions being distributed in a more uniform state in the first iron core 101, bringing a more uniform cooling effect.

[0115] In one embodiment, Fig.13a In the first punching sheet 11 shown, the number of cooling grooves 112 is equal to half the number of cooling through holes 111 , and a first core 101 in which the number of cooling grooves 112 is equal to half the number of cooling through holes 111 can be formed by arranging a plurality of such first punching sheets 11 adjacent to each other.

[0116] like Fig.13a As shown, in a first punching plate 11, along the circumference of the drive motor, the width of each cooling through hole 111 is smaller than the width of each cooling groove 112. A plurality of cooling grooves 112 are unevenly spaced around the center hole k of the first punching plate 11, and a plurality of cooling through holes 111 are evenly spaced around the center hole k of the first punching plate 11.

[0117] In one embodiment, Fig.13a As shown, each cooling groove 112 includes two sub-grooves 1121 arranged adjacently along the circumference of the drive motor, and the two sub-grooves 1121 are parallel. The interval between the two sub-grooves 1121 in each cooling groove 112 along the circumference of the drive motor is the same. Each cooling groove 112 is used to form a first layer axial flow channel d11 of a first core 101, and the interval between two adjacent cooling grooves 112 along the circumference of the drive motor is greater than the interval between the two sub-grooves 1121 in each cooling groove 112, which is convenient for the bidirectional oil circuit design according to the stator core 1.

[0118] In one embodiment, Fig.13a As shown, the outer peripheral surface of each first punching plate 11 includes a plurality of marking grooves 113, and the first punching plate 11 is welded and fixed to the inner wall of the housing 30 through the plurality of marking grooves 113. Along the circumference of the drive motor, each marking groove 113 is arranged at intervals with any cooling groove 112, and the two structures do not interfere with each other.

[0119] In one embodiment, a plurality of marking grooves 113 surround the center hole k of the first punching sheet 11, and the plurality of marking grooves 113 of each first punching sheet 11 in the stator core 1 are aligned one-to-one with the plurality of marking grooves 113 of another adjacent first punching sheet 11 along the axial direction of the drive motor. Marking the plurality of first punching sheets 11 included in a first core 101 according to the distribution pattern of the plurality of marking grooves 113 and the plurality of cooling grooves 112 can facilitate the alignment and assembly of the plurality of first punching sheets 11 included in the first core 101. Marking the two first cores 101 with the plurality of marking grooves 113 can facilitate the alignment of the first layer axial flow channel d11 and the second layer axial flow channel d12 of the two first cores 101 during the circumferential staggered arrangement. In the manufacture of the first punching sheet 11, the plurality of marking grooves 113 are also conducive to simplifying the manufacturing process of the first punching sheet.

[0120] In one embodiment, Fig.13a As shown, the multiple marking grooves 113 included in each first punching sheet 11 are evenly distributed along the circumference of the drive motor, and the central angle β between any two marking grooves 113 is an integer multiple of the central angles of any two cooling through holes 111 .

[0121] In one embodiment, Fig.13a As shown, in each first punch 11, the central angle β corresponding to any two marking grooves 113 is 30°, and half of a group of cooling grooves 112 is distributed within the range of the central angle β corresponding to any two marking grooves 113, so the central angle corresponding to the distribution range of a group of cooling grooves 112 is 60°.

[0122] In one embodiment, Fig.13a As shown, along the circumference of the driving motor, the axial flow channels 112 on both sides of each marking groove 113 are symmetrically distributed with the marking groove 113 as the symmetry axis.

[0123] In one embodiment, Fig.13a As shown, each first punching plate 11 includes a plurality of cooling grooves 112, and a dotted line frame indicates a group of axial flow channels 112. The plurality of cooling grooves 112 are arranged at intervals along the circumference of the drive motor. Fig.13b In the partial structure of the first punching plate 11 shown, each group of cooling grooves 112 includes four cooling grooves 112, and the four cooling grooves 112 include a first cooling groove 112a, a second cooling groove 112b, a third cooling groove 112c and a fourth cooling groove 112d. The first cooling groove 112a, the second cooling groove 112b, the third cooling groove 112c and the fourth cooling groove 112d are arranged in sequence along the circumference of the drive motor.

[0124] In one embodiment, along the circumference of the drive motor, the interval between the second cooling groove 112b and the third cooling groove 112c is smaller than the interval between the first cooling groove 112a and the second cooling groove 112b, the interval between the second cooling groove 112b and the third cooling groove 112c is smaller than the interval between the third cooling groove 112c and the fourth cooling groove 112d, and the interval between the third cooling groove 112c and the fourth cooling groove 112d is equal to the interval between the first cooling groove 112a and the second cooling groove 112b. The four cooling grooves 112 in each group of cooling grooves 112 are unevenly distributed, which is conducive to the multiple first-layer axial flow channels d11 of one first core 101 and the multiple second-layer axial flow channels d12 of another first core 101 to form a bidirectional flow channel.

[0125] In one embodiment, Fig.13b As shown, one marking groove 113m of two adjacent marking grooves 113 along the circumference of the drive motor is used to separate two adjacent cooling grooves 112, and the marking groove 113m is located between two groups of cooling grooves 112, and the two adjacent groups of cooling grooves 112 are axially symmetrically distributed about one marking groove 113m. Another marking groove 113n of two adjacent marking grooves 113 along the circumference of the drive motor is used to separate the second cooling groove 112b and the third cooling groove 112c in the same group of cooling grooves 112, and the four cooling grooves 112 in one group of cooling grooves 112 are axially symmetrically distributed about the marking groove 113n. In each first punch 11, multiple cooling grooves 112 are periodically distributed, and two groups of adjacent cooling grooves 112 can be regarded as one period.

[0126] Fig.14 The structure of the first punching sheet 11 of a first iron core 101 and the first punching sheet 11 of another first iron core 101 provided in the embodiment of the present application is schematically shown. Fig.14 As shown, in one embodiment, the two first punching sheets 11 are arranged adjacent to each other along the axial direction of the drive motor, and the two first punching sheets 11 respectively include the same structure and distribution of the center hole k, multiple grooves c, multiple cooling through holes 111, multiple cooling grooves 112, and multiple marking grooves 113. The center holes k of the two first punching sheets 11 are connected along the axial direction of the drive motor to accommodate the rotor 20, and the multiple grooves c of the two first punching sheets 11 are respectively connected along the axial direction of the drive motor to accommodate the stator winding 2.

[0127] Please continue to refer to Fig.14As shown, for the convenience of description, the two first punches 11 are respectively exemplified as the first punch 11i belonging to one of the first cores 101 and the first punch 11j belonging to the other first core 101. Along the circumferential direction of the drive motor, the first punch 11i is displaced with the first punch 11j by a certain angle, that is, the first punch 11i is rotated relative to the first punch 11j by a certain angle along the circumferential direction of the drive motor. The first punch 11i and the first punch 11j after circumferential dislocation satisfy the following structural form: the multiple cooling through holes 111i included in the first punch 11i and the multiple cooling through holes 111j included in the first punch 11j are respectively connected along the axial direction of the drive motor, that is, each cooling through hole 111i is connected with a cooling through hole 111j, each cooling through hole 111j is connected with a cooling through hole 111i, and the multiple cooling through holes 111i and the multiple cooling through holes 111j are connected in a one-to-one correspondence along the axial direction of the drive motor. The multiple cooling grooves 112i included in the first punching sheet 11i and the multiple cooling grooves 112j included in the first punching sheet 11j are mutually offset, and each cooling groove 112i is not connected to any cooling groove 112j. Each cooling groove 112i and each cooling groove 112j are used to receive cooling oil delivered by the housing 30. Among them, part of the structure of the first punching sheet 11i is blocked by the first punching sheet 11j, and the multiple cooling grooves 112i of the first punching sheet 11i are indicated by dotted lines.

[0128] In one embodiment, the first punching piece 11i and the first punching piece 11j after circumferential misalignment satisfy the following structural form: the multiple marking grooves 113i included in the first punching piece 11i and the multiple marking grooves 113j included in the first punching piece 11j correspond to each other in a one-to-one manner along the axial direction of the drive motor, and the welding positions of the outer peripheral surfaces of the first punching piece 11i and the first punching piece 11j are the same, which can reduce the welding difficulty of the stator core 1.

[0129] In one embodiment, the misalignment angle of the first punch 11i and the first punch 11j along the circumference of the drive motor is an integer multiple of the central angle between any two adjacent cooling holes 111 and an integer multiple of the central angle corresponding to any two adjacent marking grooves 113, which simplifies the alignment of the first punch 11i and the first punch 11j, and is beneficial to the alignment of the two first iron cores 101.

[0130] In one embodiment, please continue to refer to Fig.14 As shown, the relative rotation angle of the first punching piece 11i and the first punching piece 11j along the circumferential direction of the driving motor is the central angle corresponding to any two adjacent marking grooves 113, which is also the central angle corresponding to a group of cooling grooves 112.

[0131] In one embodiment, the central angle β corresponding to any two marking grooves 113 is 30°, the first punch 11i and the first punch 11j are relatively rotated 30° along the circumferential direction of the drive motor, and each cooling groove 112i of the first punch 11i is circumferentially offset by 30° and is not connected to each cooling groove 112j of the first punch 11j.

[0132] In one embodiment, Fig.14 As shown, along the circumference of the drive motor, the multiple axial flow channels 112i distributed between any two marking grooves 113i and the multiple cooling grooves 112j distributed between any two marking grooves 113j are alternately distributed. The central angle corresponding to a cooling groove 112i and an adjacent cooling groove 112j is the central angle corresponding to two adjacent cooling through holes 111i.

[0133] In one embodiment, each second core 102 includes one or more Fig.15a The second punching sheet 12 shown, the one or more second punching sheets 12 are sequentially arranged between a first core 101 and a third core 103 along the axial direction of the drive motor. Each second punching sheet 12 includes a center hole k and a plurality of grooves c, the center hole k and each groove c penetrate the second punching sheet 12 along the axial direction of the drive motor, each groove c is connected to the center hole k along the radial direction of the drive motor, and the plurality of grooves c are arranged at intervals along the circumferential direction of the drive motor. When there are multiple second punching sheets 12, the multiple center holes k of the multiple second punching sheets 12 are connected to form a part of the center hole K of the stator core 1, and the multiple grooves c of the multiple second punching sheets 12 are respectively connected to form a part of the multiple winding slots Z of the stator core 1.

[0134] like Fig.15a As shown, each second punching plate 12 includes multiple groups of oil storage grooves 121, and the multiple groups of oil storage grooves 121 are distributed around the center hole k of the second punching plate 12. Each group of oil storage grooves 121 includes multiple oil storage grooves 121, and the multiple oil storage grooves 121 included in each group of oil storage grooves 121 are arranged in sequence along the circumference of the drive motor. Each oil storage groove 121 is used to form a radial flow channel d2 of the second iron core 102. The notch of each oil storage groove 121 is away from the center hole k of the second punching plate 12 in the radial direction of the drive motor, and the bottom of each oil storage groove 121 is toward the center hole k of the second punching plate 12 in the radial direction of the drive motor. The bottom of each oil storage groove 121 is used to connect the second layer of axial flow channel d12 of the first iron core 101.

[0135] by Fig.15aTaking a second punching plate 12 as an example, along the circumferential direction of the drive motor, each oil storage groove 121 is arranged between two grooves c. Along the radial direction of the drive motor, the distance between each oil storage groove 121 and the center hole k of the second punching plate 12 is smaller than the distance between the bottom of each groove c and the center hole k. Each groove c is used to accommodate the stator winding 2, and the cooling oil passing through the oil storage groove 121 can exchange heat through the second punching plate 12, take away the heat generated by the stator winding 2, and realize oil cooling of the stator 10.

[0136] In one embodiment, along the circumference of the drive motor, the circumferential width of one end p2 of each oil storage groove 121 used to connect to the outer peripheral surface of the second punching piece 12 is greater than the circumferential width p1 of one end of the oil storage groove 121 used to connect to the cooling through hole 111, so that each oil storage groove 121 has an oil storage function, and being connected in series in the oil cooling circuit is conducive to ensuring that the oil pressure meets the requirements of spray cooling.

[0137] In one embodiment, Fig.15b In the partial structure of a second punching sheet 12 shown, the shapes of two adjacent oil storage grooves 121 along the circumference of the driving motor are different, and the shapes of the two groove walls of each oil storage groove 121 opposite to each other along the circumference of the driving motor are different, so that the oil storage groove 121 can have a larger area along the circumference of the driving motor. In the structural design of the stator core 1, different structural forms can be selected according to the position of the connected first-layer axial flow channel d11 or the injection oil channel d3, so that each oil storage groove 121 is easier to connect with a first-layer axial flow channel d11, or one or more injection oil channels d2.

[0138] Fig.16 The diagram is a partial structural diagram of a second punching sheet 12 and an adjacent first punching sheet 11. The second punching sheet 12 is a punching sheet of the second iron core 102 used to be arranged adjacent to the first iron core 101, and the first punching sheet 11 is a punching sheet of the first iron core 101 used to be arranged adjacent to the second iron core 102. Fig.16 As shown, along the radial direction of the drive motor, the length of each oil storage groove 121 is greater than the spacing between each cooling through hole 111 in each first punch 11 and the outer peripheral surface of the first punch 11. The spacing between each oil storage groove 121 and the axis of the stator 10 is less than or equal to the sum of the spacing between each cooling through hole 111 and the axis of the stator 10 and the radial height of the cooling through hole 111. With the center hole k of the second punch 12 as a reference, the spacing between each oil storage groove 121 and the center hole k is less than or equal to the sum of the spacing between each cooling through hole 111 and the center hole k and the radial height of the cooling through hole 111, so that the bottom of each oil storage groove 121 can be connected to a cooling through hole 111.

[0139] like Fig.16As shown, an oil storage groove 121m connected to a cooling groove 112 is used as a part of the first radial flow channel d21, and the oil storage groove 121m connects a cooling groove 112 and a cooling through hole 111 along the radial direction of the drive motor. The notch of each oil storage groove 121m is used to connect a cooling through hole 111, and the notch of each oil storage groove 121m is used to connect a cooling groove 112. An oil storage groove 121n that is not connected to the cooling groove 112 is used as a part of the second radial flow channel d22, and the bottom of each oil storage groove 121n is used to connect a cooling through hole 111.

[0140] In one embodiment, Fig.16 As shown, the number of oil storage grooves 121m serving as the first radial flow channels d21 in each group of oil storage grooves 121 is the same as the number of oil storage grooves 121n serving as the second radial flow channels d22, and the cooling oil with different flow directions is distributed more evenly in the second punching plate 12, which is conducive to uniform heat dissipation.

[0141] In one embodiment, Fig.16 As shown, along the circumference of the drive motor, a group of cooling grooves 112 is indicated by a dotted frame. The group of cooling grooves 112 is distributed between two marking grooves 113, and another marking groove 113 is distributed between the two marking grooves 113. A corresponding group of oil storage grooves 121 is distributed between the two marking grooves 113, and the group of oil storage grooves 121 includes eight oil storage grooves 121, and four oil storage grooves 121m of the eight oil storage grooves 121 of each group of oil storage grooves 121 are respectively used as four first radial flow channels d21, and the four oil storage grooves 121m are respectively used to connect the four cooling grooves 112 in a group of cooling grooves 112 in a one-to-one manner. The other four oil storage grooves 121n of the eight oil storage grooves 121 of each group of oil storage grooves 121 are respectively used as four second radial flow channels d22, and the four oil storage grooves 121n are circumferentially offset and not connected with any cooling groove 112. In each second iron core 102, the flow directions of the cooling oil in the multiple oil storage tanks 121 in each group of oil storage tanks 121 cooperate with each other to form multiple groups of bidirectional radial flow channels along the circumference of the drive motor, further improving the heat dissipation balance of the stator 10, which is beneficial to improving the performance of the drive motor 100.

[0142] In one embodiment, along the circumference of the driving motor, two oil storage tanks 121m of the four oil storage tanks 121m serving as the first radial flow channel d21 are adjacently arranged between two oil storage tanks 121n serving as the second radial flow channel d22, and the other two oil storage tanks 121m of the four oil storage tanks 121m serving as the first radial flow channel d21 are respectively arranged between the two oil storage tanks 121n of the second radial flow channel d22.

[0143] Fig.17The stator core 1 has two first cores 101 and two second punching sheets 12. Figure 8 Arranged in the manner shown, each second punching sheet 12 is a punching sheet of a second core 102 arranged adjacent to the first core 101 .

[0144] In one embodiment, Fig.17 As shown, along the axial direction of the drive motor, a second punching plate 12i is arranged on the side of a first core 101 away from another first core 101, and the second punching plate 12i is adjacent to a first punching plate 11i of a first core 101. Another second punching plate 12j is arranged on the side of another first core 101 away from a first core 101, and the second punching plate 12j is adjacent to a first punching plate 11j of another first core 101. The second punching plate 12i includes a plurality of oil storage grooves 121i, a part of the oil storage grooves 121i is connected to a cooling groove 112i of an adjacent first punching plate 11i along the axial direction of the drive motor, and a part of the oil storage grooves 121i is not connected to any cooling groove 112. The second punching plate 12j includes a plurality of oil storage grooves 121j, a part of the oil storage grooves 121j is connected to a cooling groove 112j of an adjacent first punching plate 11j along the axial direction of the drive motor, and a part of the oil storage grooves 121j is not connected to any cooling groove 112j.

[0145] Please continue to refer to Fig.17 As shown, each oil storage groove 121i is connected to a cooling through hole 111i of the adjacent first punching plate 11i along the axial direction of the drive motor, and the multiple oil storage grooves 121i of the second punching plate 12i are connected to the multiple cooling through holes 111i of the first punching plate 11i in a one-to-one correspondence along the axial direction of the drive motor. Each oil storage groove 121j is connected to a cooling through hole 111j of the adjacent first punching plate 11j along the axial direction of the drive motor, and the multiple oil storage grooves 121j of the second punching plate 12j are connected to the multiple cooling through holes 111j of the first punching plate 11j in a one-to-one correspondence along the axial direction of the drive motor.

[0146] In one embodiment, Fig.17 Taking the second punching plate 12j and the first punching plate 11j in the example, a part of the oil storage tank 121j is connected to a cooling groove 112j and a cooling through hole 111j along the axial direction of the drive motor, and the cooling oil in the cooling groove 112j can be guided to the cooling through hole 111j, and the cooling oil outside the first punching plate 11j can be guided to the inside of the first punching plate 11j. This part of the oil storage tank 121j is used as the first radial flow channel d21. The other part of the oil storage tank 121j that is not connected to the cooling groove 112j is used as the second radial flow channel d22.

[0147] In one embodiment, between a cooling through hole 111i and a cooling through hole 111j connected to the first punch 11i and the first punch 11j, the cooling through hole 111i is connected to an oil storage tank 121i connected to a cooling groove 112i, and the cooling through hole 111j is connected to an oil storage tank 121j that is not connected to the cooling groove 112j. Alternatively, between a cooling through hole 111i and a cooling through hole 111j connected to the first punch 11i and the first punch 11j, the cooling through hole 111i is connected to an oil storage tank 121i that is not connected to the cooling groove 112i, and the cooling through hole 111j is connected to an oil storage tank 121j that is connected to a cooling groove 112j.

[0148] by Fig.17 The structure shown is for reference. For the entire stator core 1, a cooling through hole 111i of a first punch 11i and another cooling through hole 111j of another first punch 11j are connected along the axial direction of the drive motor to form a channel for cooling oil circulation, and the channel is used to form a second-layer axial flow channel d12. The cooling oil in any channel is either connected to a cooling groove 112i through an oil storage tank 121i or connected to a cooling groove 112j through an oil storage tank 121j, and the cooling oil at the outer peripheral surface of the stator core 1 can be guided to the inside of the stator core 1. Only one end of each channel can be connected to a cooling groove 112 through an oil storage tank 121.

[0149] In one embodiment, each third core 103 includes a plurality of third punching sheets 13. The structure of the third punching sheets 13 can refer to Fig.18 As shown. Each third punching sheet 13 includes a center hole k and a plurality of grooves c. The center hole k and each groove c penetrate the third punching sheet 13 along the axial direction of the driving motor. Each groove c is connected to the center hole k along the radial direction of the driving motor. The plurality of grooves c are arranged at intervals along the circumferential direction of the driving motor. When there are multiple third punching sheets 13, the multiple center holes k of the multiple third punching sheets 13 are connected to form a part of the center hole K of the stator core 1, and the multiple grooves c of the multiple third punching sheets 13 are respectively connected to form a part of the multiple winding slots Z of the stator core 1.

[0150] like Fig.18 As shown, each third punching sheet 13 includes a plurality of pairs of oil outlet holes 131, and the dotted box indicates a pair of oil outlet holes 131. The plurality of pairs of oil outlet holes 131 are distributed around the central hole k of the third punching sheet 13, and the interval between two pairs of oil outlet holes 131 adjacent to each other along the circumference of the third punching sheet 13 is greater than the interval between two oil outlet holes 131 in each pair of oil outlet holes 131. This is beneficial for the oil outlet holes 131 to avoid the first layer of axial flow channel d11 of the first core 101 along the circumference of the drive motor, thereby facilitating the flow channel design of the stator core 1.

[0151] In one embodiment, Fig.18 As shown, the spacing between the multiple pairs of oil outlet holes 131 included in a third punching plate 13 and the axis of the stator 10 varies along the radial direction of the drive motor. Along the radial direction of the drive motor, the spacing between the two oil outlet holes 131 included in each pair of oil outlet holes 131 and the axis of the stator 10 is equal, and the spacing between the two adjacent pairs of oil outlet holes 131 and the axis of the stator 10 is not equal. Taking two pairs of adjacent oil outlet holes 131 as an example, compared with one oil outlet hole 131q in one pair of oil outlet holes 131 and one oil outlet hole 131p in the other pair of oil outlet holes 131, along the radial direction of the drive motor, the spacing r1 between the oil outlet hole 131p and the axis of the stator 10 is greater than the spacing r2 between the oil outlet hole 131q and the axis of the stator 10. Along the circumferential direction of the drive motor, the corresponding central angle between any two pairs of adjacent oil outlet holes 131 is twice the corresponding central angle between any two adjacent grooves c.

[0152] In one embodiment, along Fig.18 Observe the multiple pairs of oil outlet holes 131 in the counterclockwise direction of the viewing angle shown, with the position indicated by W as the starting position and the position indicated by V as the end position, and the distances between the multiple pairs of oil outlet holes 131 and the axis of the drive motor 100 along the radial direction of the drive motor gradually decrease. The distance between the pair of oil outlet holes 131 at the position indicated by W and the axis of the drive motor 100 along the radial direction of the drive motor is the largest, and the distance between the pair of oil outlet holes 131 at the position indicated by V and the axis of the stator 10 along the radial direction of the drive motor is the smallest. In one embodiment, the multiple pairs of oil outlet holes 131 are arranged in an asymptotic manner counterclockwise or clockwise along the circumference of the drive motor, and the distances between any two adjacent pairs of oil outlet holes 131 and the axis of the drive motor 100 along the radial direction of the drive motor are different.

[0153] Fig.19 It is a partial structure of the stator core 1, which includes a first core 101, a second core 102 and a third punching sheet 13. The first core 101 includes a plurality of first punching sheets 11, the second core 102 includes a second punching sheet 12, and the third punching sheet 13 is arranged on the side of the second punching sheet 12 away from the first core 101 as a part of the third core 103, and the part blocked by other structures is shown in dotted lines.

[0154] like Fig.19 As shown, each cooling through hole 111 of a portion of the cooling through holes 111 of the first punch 11 is connected to a cooling groove 112 through an oil storage groove 121, and each cooling through hole 111 of another portion of the cooling through holes 111 of the first punch 11 is connected to an oil outlet hole 131 through an oil storage groove 121. Each oil storage groove 121 is connected to a cooling through hole 111.

[0155] In one embodiment, please continue to refer to Fig.19As shown, a third punching sheet 13 in each third iron core 103 and a second punching sheet 12 in the second iron core 102 are arranged adjacent to each other along the axial direction of the drive motor, and the groove wall of each oil storage groove 121 in the second punching sheet 12 for connecting an oil outlet hole 131 is used to block one oil outlet hole 131 in a pair of oil outlet holes 131 in the third punching sheet 13, and each oil storage groove 121 in the second punching sheet 12 for connecting an oil outlet hole 131 is used to connect the other oil outlet hole 131 in a pair of oil outlet holes 131 in a third punching sheet 13. The dotted ellipse illustrates a pair of oil outlet holes 131 of the third punching sheet 13. One of the two oil outlet holes 131 included in each pair of oil outlet holes 131 is connected to an oil storage groove 121 along the axial direction of the drive motor, and the other is blocked by the second punching sheet 12. If the oil storage tank 121 needs to be connected to an oil outlet hole 131 , the oil storage tank 121 only needs to be connected to an oil outlet hole 131 with a smaller circumferential spacing in a group of oil outlet holes 131 , which is beneficial to the structural design of the third iron core 103 and the second iron core 102 .

[0156] In order to make the plurality of oil storage grooves 121 of the second punching plate 12 meet the above conditions, the shape of each oil storage groove 121 of the second punching plate 12 can be a special shape. Fig.19 As shown, in one embodiment, along the circumference of the drive motor, the circumferential width of the notch of an oil storage groove 121 for connecting to a cooling groove 112 is smaller than the circumferential width of the notch of the oil storage groove 121 for connecting to an oil outlet hole 131. The notch of the oil storage groove 121 is an opening of the outer circumferential surface of the oil storage groove 121 for connecting to the second punching plate 12. Some oil storage grooves 121 connected to the cooling groove 112 cannot be completely connected to the cooling groove 112 along the axial direction of the drive motor, and a part of the second punching plate 12 may block a part of the cooling groove 112, preventing the cooling groove 112 from being connected in parallel with the cooling through hole 111.

[0157] Please continue to refer to Fig.19 As shown, along the radial direction of the drive motor, the distance between each oil outlet hole 131 and the axis of the stator 10 is smaller than the distance between each cooling groove 112 and the axis of the stator 10. With the center hole k of the third punch 13 and the first punch 11 as a reference, the distance between each oil outlet hole 131 and the center hole k is smaller than the distance between each cooling groove 112 and the center hole k, ensuring that the cooling groove 112 will not be directly connected to the oil outlet hole 131, preventing the cooling groove 112 from being connected to the cooling through hole 111 to make the oil passages parallel.

[0158] In one embodiment, among the multiple groups of cooling grooves 112 included in the first punching plate 11, the cooling grooves 112 of each group are axially symmetrically distributed about a marking groove 113. The communication mode between any group of cooling grooves 112 and the oil storage tank 121, the oil outlet hole 131, and the cooling through hole 111 is also axially symmetrical.

[0159] Fig. 20 1 is a cross-sectional view of a partial structure of the stator core 1, which includes two first cores 101, two second cores 102, and third punching sheets 13. Each first core 101 includes a plurality of first punching sheets 11, each second core 102 includes a second punching sheet 12, and each third punching sheet 13 is arranged as a part of a third core 103 on a side of a second punching sheet 12 away from the first core 101. Figure 8 In the manner shown, each second punch 12 is adjacent to a first punch 11 and a third punch 13. Fig.19 The two second punching sheets 12 are respectively a second punching sheet 12i and a second punching sheet 12j, the second punching sheet 12i is arranged between a first punching sheet 11i and a third punching sheet 13i, and the second punching sheet 12j is arranged between a first punching sheet 11j and a third punching sheet 13j.

[0160] like Fig. 20 As shown, in one embodiment, between a group of interconnected cooling through holes 111i and cooling through holes 111j, the cooling through hole 111i is connected to an oil outlet hole 131i through an oil storage tank 121i, and the cooling through hole 111j is connected to a cooling groove 112j through an oil storage tank 121j. The cooling through hole 111i is used to form a part of the second layer axial flow channel d12, the cooling through hole 111j is used to form a part of the second layer axial flow channel d12, the oil storage tank 121m is used as the second radial flow channel d22, the oil storage tank 121n is used for the first radial oil channel d21, the cooling groove 112j is used to form a part of the first layer axial flow channel d11, and the oil outlet hole 131i is used to form a part of the injection flow channel d3. The cooling groove 112j, the oil storage tank 121j, the cooling through hole 111j, the cooling through hole 111i, the oil storage tank 121i and the oil outlet hole 131i are connected in sequence to form a circulation circuit.

[0161] Please continue to refer to Fig. 20 As shown, it can be understood that the cooling groove 112i, which is circumferentially offset and not connected to the cooling groove 112j, can be connected to another cooling through-hole 111i through another oil storage groove 121i, and the cooling groove 112i can be connected to another oil storage groove 121j through the other cooling through-hole 111i and another cooling through-hole 111j connected to the cooling through-hole 111i, and the other oil storage groove 121j is connected to an oil outlet hole 131j, thereby forming another circulation circuit.

[0162] In one embodiment, Fig.21A partial structure of a stator core 1 is shown, and each third core 103 includes a plurality of third punching sheets 13 along the axial direction of the drive motor. In one embodiment, each oil outlet hole 131 of each third punching sheet 13 can be connected with an oil outlet hole 131 of an adjacent third punching sheet 13. After the plurality of third punching sheets 13 are stacked along the axial direction of the drive motor, the plurality of oil outlet holes 131 of each third punching sheet 13 can be respectively connected with the plurality of oil outlet holes 131 of another third punching sheet 13, and the plurality of oil outlet holes 131 connected in sequence form an oil injection channel d3. The structure and arrangement of each third punching sheet 13 are designed so that the spraying direction of the cooling oil can be changed after the plurality of third punching sheets 13 are arranged adjacently. In one embodiment, among the plurality of pairs of oil outlet holes 131 of each third punching sheet 13, one of the two oil outlet holes 131 included in a pair of oil outlet holes 131 is used for oil injection.

[0163] In one embodiment, a plurality of third punches 13 are adjacent to each other in the axial direction of the driving motor and are rotationally stacked, so that a plurality of third punches 13 in each third core 103 are staggeredly arranged in the circumferential direction of the driving motor, and at least one oil outlet hole 131 in each pair of oil outlet holes 131 in each third punch 13 is used to connect an oil outlet hole 131 in another adjacent third punch 13 to form an oil injection channel d3.

[0164] Fig.22a The structure of two third punching plates 13 being stacked in a relatively circumferential rotation around the axis of the driving motor 100 is illustrated, and the two third punching plates 13 are stacked after being rotated circumferentially by an angle twice the corresponding central angle between adjacent grooves c. Fig.22a As shown, an oil outlet hole 131q on a third punching sheet 13 is connected to an oil outlet hole 131q on another third punching sheet 13, and the distance between the oil outlet hole 131q and the axis of the drive motor 100 is smaller than the distance between the oil outlet hole 131p and the axis of the drive motor 100, and the oil outlet hole 131q and the oil outlet hole 131p can be connected to form an inclined oil channel. When the third core 103 includes a plurality of third punching sheets 13, a plurality of third punching sheets 13 of the same structure can be rotated and stacked to form an inclined flow channel, simplifying the manufacturing process and reducing production costs.

[0165] A plurality of third punching sheets 13 are Fig.22a The partial structures after being rotated and stacked in sequence can be referred to Figure 22bAs shown, any two adjacent third punching plates 13 are rotated and misaligned along the circumferential direction of the drive motor by the central angles corresponding to the two groups of adjacent oil outlet holes 131, so as to form a plurality of inclined oil injection paths. In the radial direction of the drive motor, the distance between an oil outlet hole 131 of a third punching plate 13 and the axis of the drive motor 100 is smaller than the distance between an oil outlet hole 131 of another connected third punching plate 13 and the axis of the stator 10. Taking an adjacent oil outlet hole 131m and another adjacent oil outlet hole 131n as an example, in the radial direction of the drive motor, the distance between the oil outlet hole 131m and the axis of the drive motor 100 is smaller than the distance between the oil outlet hole 131n and the axis of the drive motor 100.

[0166] In one embodiment, combining Fig.18 , Fig.22a as well as Figure 22b ,like Fig.23 As shown, two third punching plates 13 are rotated and stacked, and a group of oil outlet holes 131v indicated by the V position of the third punching plate 13 of the bottom layer corresponds to a group of oil outlet holes 131w at the W position of the third punching plate 13 of the top layer along the axial direction of the drive motor, and a group of oil outlet holes 131w at the position indicated by W of the third punching plate 13 of the top layer is blocked by the third punching plate 13 of the bottom layer. A group of oil outlet holes 131v indicated by the V position of the third punching plate 13 of the top layer is connected to a group of oil outlet holes 131 adjacent to the V position of the third punching plate 13 of the bottom layer in the clockwise direction to form an inclined channel. When multiple third punching plates 13 are arranged axially, there is always a pair of oil outlet holes 131 between any two adjacent third punching plates 13 that are blocked and cannot be connected, so that the stator core 1 is unevenly sprayed along the circumference of the drive motor. In specific applications, by adjusting the structural design of the oil outlet holes 131 of the multiple third punching sheets 13, it is possible to adjust whether the multiple oil outlet holes 131 of the multiple third punching sheets 13 can be connected to form an oil injection oil circuit, thereby accurately adjusting the range of oil injection cooling of the stator winding 2 to meet the cooling requirements.

[0167] Fig.24a The partial structure of the stator core 1 is shown, which includes the adjacent second core 102 and the third core 103, the second core 102 includes a second punching sheet 12, and the third core 103 includes a plurality of third punching sheets 13. In one embodiment, taking a plurality of oil outlet holes 131 connected in sequence and connected to an oil storage tank 121 of the second punching sheet 12 as an example, the plurality of oil outlet holes 131 are divided into two parts connected along the axial direction of the drive motor, one part of the oil outlet holes 131 is connected in sequence to form a straight flow channel d31, and the other part of the oil outlet holes 131 is connected in sequence to form an oblique flow channel d32 oblique to the axial direction of the stator 10. The straight flow channel d31 is connected to an oil storage tank 121, and the straight flow channel d31 can guide the cooling oil in the oil storage tank 121 to the oblique flow channel d32, and the oblique flow channel d32 can spray the cooling oil in a manner inclined to the axis of the stator, so as to better spray and cool the stator winding 2.

[0168] Combination Figure 24b As shown, along the axial direction of the drive motor, the distance between the third punching plate 13 where the oil outlet hole 131m is located and the second punching plate 12 is greater than the distance between the third punching plate 13 where the oil outlet hole 131n is located and the second punching plate 12, and the channel formed by the oil outlet hole 131m and the oil outlet hole 131n has a tendency to deviate toward the axial direction of the drive motor 100. Fig.24a and Figure 24b After being arranged in the manner shown, each oil outlet hole 131 of a third punch 13 is offset toward the axial direction of the stator 10 relative to an oil outlet hole 131 of another third punch 13 that is connected to the drive motor in the radial direction of the drive motor, thereby forming a flow channel inclined toward the axis of the drive motor 100 along the radial direction of the drive motor, thereby changing the oil outlet direction of the cooling oil.

[0169] In one embodiment, Fig.25 As shown, along the circumference of the drive motor, each oil outlet hole 131 of a third punching plate 13 is circumferentially offset and connected with an oil outlet hole 131 of another third punching plate 13, and the channel formed by the connection of the two oil outlet holes 131 has a tendency to tilt along the circumference of the drive motor. A plurality of third punching plates 13 are arranged adjacent to each other along the axial direction of the drive motor, and the channel formed by each group of sequentially connected oil outlet holes 131 is offset along the circumference of the stator and toward the center of the stator along the radial direction of the drive motor, so that the cooling oil can be sprayed in a rotating manner.

[0170] In summary, the drive motor 100 provided in the embodiment of the present application dissipates heat from the stator core 1 by stacking different stator punching sheets to form an oil cooling circuit with inner and outer layers connected in series and bidirectional oil spraying, thereby simplifying the structure of the bidirectional double-layer flow channel in the stator core 1, which is not only beneficial to improving the structural stability of the stator core 1, but also beneficial to reducing the manufacturing cost of the drive motor 100. The above-mentioned bidirectional double-layer flow channel can avoid the problems of low oil pressure and difficult oil injection and uneven oil distribution without increasing the amount of oil, thereby improving the oil cooling effect and optimizing the performance of the drive motor 100. In one embodiment, in a scenario where two motors share an oil pump, the cooling oil distribution is small, and the drive motor 100 can still maintain a relatively efficient oil cooling effect.

[0171] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A bidirectional double-layer oil-cooled drive motor, characterized in that: The housing of the drive motor is used to accommodate and fix the stator core of the drive motor, and the stator core includes a first core, a second core and a third core, and the second core is arranged between the first core and the third core along the axial direction of the drive motor, wherein: The first core comprises a plurality of first-layer axial flow channels and a plurality of second-layer axial flow channels, the distance between each of the first-layer axial flow channels and the central hole of the stator core is greater than the distance between each of the second-layer axial flow channels and the central hole of the first core, the plurality of first-layer axial flow channels are distributed around the central hole of the second core, and the plurality of second-layer axial flow channels are distributed around the central hole of the second core; The one second core comprises a plurality of groups of bidirectional radial flow channels, the plurality of groups of bidirectional radial flow channels are distributed around the central hole of the one second core, each group of the bidirectional radial flow channels comprises a plurality of radial flow channels, the plurality of radial flow channels of each group of the bidirectional radial flow channels are sequentially arranged along the circumference of the one second core, the plurality of radial flow channels in each group of the bidirectional radial flow channels comprises a plurality of first radial flow channels and a plurality of second radial flow channels, and the flow direction of the cooling oil in each of the first radial flow channels is opposite to the flow direction of the cooling oil in each of the second radial flow channels; The third core includes a plurality of oil injection channels, each of the first radial channels is used to connect a first layer axial channel and a second layer axial channel, and each of the second radial channels is used to connect another second layer axial channel and one or more oil injection channels.

2. The drive motor according to claim 1, characterized in that: The stator core further includes another first core, and the another first core and the one first core are arranged adjacent to each other along the axial direction of the drive motor, wherein: The other first iron core and the one first iron core are arranged in a staggered manner along the circumferential direction of the drive motor, and the multiple first-layer axial flow channels of the one first iron core and the multiple first-layer axial flow channels of the other first iron core are arranged in a staggered manner along the circumferential direction of the drive motor; The housing of the drive motor includes an oil inlet hole, which is used to transport cooling oil to the multiple first-layer axial flow channels of the first iron core and the multiple first-layer axial flow channels of the second iron core. The flow direction of the cooling oil in the multiple first-layer axial flow channels of the first iron core is opposite to the flow direction of the cooling oil in the multiple first-layer axial flow channels of the other first iron core.

3. The drive motor according to claim 2, characterized in that: The stator core further includes another second core and another third core, wherein the other second core is arranged between the other first core and the other third core along the axial direction of the drive motor, and the multiple second-layer axial flow channels of the one first core are connected one-to-one to the multiple second-layer axial flow channels of the other first core along the axial direction of the drive motor, wherein: One of the first radial flow channels of the one second core is connected with one of the second radial flow channels of the other second core along the axial direction of the drive motor through one of the second-layer axial flow channels of the one first core and one of the second-layer axial flow channels of the other first core.

4. The drive motor according to any one of claims 1 to 3, characterized in that: Each of the first cores includes a plurality of first punches, and the plurality of first punches in each of the first cores are sequentially arranged along the axial direction of the first core. Each of the first punches includes a plurality of groups of cooling grooves and a plurality of cooling through holes, and the plurality of cooling grooves surround the outer circumferential surface of the first punch along the circumferential direction of the drive motor, and each group of cooling grooves includes a plurality of cooling grooves, and the concave direction of each cooling groove faces the central hole of the first punch. The plurality of cooling through holes are spaced around the central hole of the first punch along the circumferential direction of the drive motor, and each of the cooling through holes and each of the cooling grooves penetrates the first punch along the axial direction of the drive motor, wherein: The number of the cooling grooves in each of the first iron cores is less than the number of the cooling through holes, and the multiple cooling grooves of one of the first punching sheets in each of the first iron cores are connected one-to-one along the axial direction of the drive motor to form multiple first-layer axial flow channels, and the multiple cooling through holes of each of the first punching sheets in the stator iron core are connected one-to-one along the axial direction of the stator iron core to form multiple second-layer axial flow channels.

5. The driving motor according to claim 4, characterized in that: The number of the cooling grooves in each of the first cores is equal to half the number of the cooling through holes, and the width of the cooling through hole in each of the first punching sheets along the circumference of the first punching sheet is smaller than the width of each of the cooling grooves, wherein: The plurality of cooling grooves are unevenly spaced and distributed around the central hole of the first punching plate, and the plurality of cooling through holes are evenly spaced and distributed around the central hole of the first punching plate.

6. The drive motor according to claim 4 or 5, characterized in that: Each of the cooling grooves includes two sub-grooves, and the interval between the two sub-grooves in each of the cooling grooves along the circumference of the first punching sheet is smaller than the groove width of each of the sub-grooves, wherein: The interval between the two sub-grooves in each cooling groove along the circumference of the first punch is the same, and the interval between two adjacent cooling grooves along the circumference of the first punch is greater than the interval between the two sub-grooves in each cooling groove.

7. The driving motor according to any one of claims 4 to 6, characterized in that: Each group of cooling grooves includes four cooling grooves, and the four cooling grooves include a first cooling groove, a second cooling groove, a third cooling groove and a fourth cooling groove, wherein: The first cooling groove, the second cooling groove, the third cooling groove and the fourth cooling groove are arranged in sequence along the circumference of the first punch plate, the interval between the second cooling groove and the third cooling groove along the circumference of the first punch plate is smaller than the interval between the first cooling groove and the second cooling groove along the circumference of the first punch plate, the interval between the second cooling groove and the third cooling groove along the circumference of the first punch plate is smaller than the interval between the third cooling groove and the fourth cooling groove along the circumference of the first punch plate, and the interval between the third cooling groove and the fourth cooling groove along the circumference of the first punch plate is equal to the interval between the first cooling groove and the second cooling groove along the circumference of the first punch plate.

8. The driving motor according to claim 7, characterized in that: The outer peripheral surface of each first punching sheet further includes a plurality of marking grooves, and the plurality of marking grooves surround the center hole of the first punching sheet, and the plurality of marking grooves of each first punching sheet in the stator core are aligned one-to-one with the plurality of marking grooves of another adjacent first punching sheet along the axial direction of the drive motor, wherein: One of the two marking grooves adjacent to each other along the circumference of the first punch is used to separate two adjacent cooling grooves, and the other of the two marking grooves adjacent to each other along the circumference of the first punch is used to separate the second cooling groove and the third cooling groove in the same group of cooling grooves.

9. The driving motor according to any one of claims 1 to 8, characterized in that: Each of the second iron cores includes one or more second punching sheets, and the one or more second punching sheets are sequentially arranged between one of the first iron cores and one of the third iron cores along the axial direction of the drive motor; Each of the second punching sheets includes a plurality of groups of oil storage grooves, and the plurality of groups of oil storage grooves are distributed around the central hole of the second punching sheet along the circumference of the second punching sheet, and each group of the oil storage grooves includes a plurality of the oil storage grooves, wherein: The shapes of the two adjacent oil storage grooves along the circumferential direction of the second punching plate are different, and the shapes of the two groove walls of each oil storage groove opposite to each other along the circumferential direction of the second punching plate are different.

10. The driving motor according to claim 9, characterized in that: The slot opening of each of the oil storage grooves is away from the center hole of the second punching sheet along the radial direction of the second punching sheet, the slot bottom of each of the oil storage grooves is toward the center hole of the second punching sheet along the radial direction of the second punching sheet, and the length of each of the oil storage grooves along the radial direction of the second punching sheet is greater than the interval between each of the cooling holes in each of the first punching sheets and the outer peripheral surface of the first punching sheet.

11. The drive motor according to claim 9 or 10, characterized in that: The number of the oil storage grooves serving as the first radial flow passages in each group of the oil storage grooves is the same as the number of the oil storage grooves serving as the second radial flow passages.

12. The driving motor according to claim 11, characterized in that: Each group of the oil storage tanks includes eight oil storage tanks, four of the eight oil storage tanks in each group of the oil storage tanks are used as four of the first radial flow channels, and the other four of the eight oil storage tanks in each group of the oil storage tanks are used as four of the second radial flow channels, wherein: Along the circumference of the second punching plate, two of the four oil storage tanks serving as the first radial flow channels are adjacently arranged between the two oil storage tanks serving as the second radial flow channels, and the other two of the four oil storage tanks serving as the first radial flow channels are respectively arranged between the two oil storage tanks serving as the second radial flow channels.

13. The driving motor according to any one of claims 9 to 12, characterized in that: Each of the third cores includes a plurality of third punching sheets, each of the third punching sheets includes a plurality of pairs of oil outlet holes, the plurality of pairs of oil outlet holes are distributed around the central hole of the third punching sheet along the circumference of the drive motor, and the interval between two pairs of the oil outlet holes adjacent to each other along the circumference of the drive motor is greater than the interval between two oil outlet holes in each pair of the oil outlet holes, wherein: The plurality of third punching sheets in each of the third iron cores are sequentially arranged adjacent to each other along the axial direction of the drive motor, and the plurality of third punching sheets in each of the third iron cores are sequentially arranged in a staggered manner along the circumferential direction of the drive motor, and at least one oil outlet hole in each pair of the oil outlet holes in each of the third punching sheets is used to connect with one of the oil outlet holes in another adjacent third punching sheet to form an oil injection flow channel; A third punching plate in each of the third iron cores and a second punching plate in the second iron core are arranged adjacent to each other along the axial direction of the drive motor, and each of the oil storage grooves in a second punching plate used for connecting the oil injection channel is used for connecting one of a pair of oil outlet holes in the third punching plate, and the other oil outlet hole in the pair of oil outlet holes is blocked by the second punching plate.

14. A powertrain, characterized in that: The powertrain includes a reducer and a drive motor as described in any one of claims 1 to 13, and the drive motor is connected to the wheels of the electric vehicle through the reducer.

15. An electric vehicle, characterized in that: The electric vehicle comprises wheels and the powertrain according to claim 14, wherein the powertrain is used to drive the wheels.

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