Coaxial drive device and vehicle

Abstract

The application provides a coaxial driving device and a vehicle, wherein the coaxial driving device comprises a shell, a stator and a rotor, the shell comprises an end cover, the end cover is provided with a first overflow channel, the rotor shaft has a cavity inside, the cavity penetrates through both ends of the rotor shaft, the rotor shaft is provided with a second hole, the second hole is in communication with the cavity and the rotor, a through shaft is arranged in the cavity of the rotor shaft, one end of the through shaft extends to the end cover, the through shaft is provided with a second overflow channel, the through shaft is provided with a third hole and a fourth hole in communication with the second overflow channel. After the cooling medium flows out from the first hole, the cooling medium can be buffered in the buffer groove and fill the buffer groove, and the pressure in the buffer groove is easy to increase. Therefore, in the case that the through shaft rotates at high speed and the first hole and the third hole are misaligned, the cooling medium can also flow into the third hole, and the cooling effect on the rotor is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle power systems, in particular to a coaxial driving device and a vehicle. BACKGROUND

[0002] The driving motor is a core component of a new energy vehicle, which has the characteristics of compact structure, high power density and high efficiency. However, the motor generates a large amount of heat during operation, and high temperature affects the output performance of the motor. Therefore, how to control the temperature rise of the motor during operation is a key factor to improve the performance of the new energy vehicle.

[0003] In the driving mode of the electric vehicle, the coaxial electric drive has the advantages of high mechanical efficiency and compact structure. However, due to the through shaft crossing the entire driving mechanism, there are certain difficulties in the oil feeding mode of the rotor. In the prior art, two methods are usually used to realize the cooling and oil feeding of the coaxial electric drive: one is to feed oil through the gap between the through shaft and the motor shaft, but this oil feeding mode requires high sealing between the through shaft and the motor shaft, and the system has a large radial size, which is not conducive to the selection of parts, and the bearing loss is also increased; the other is to set an oil channel in the through shaft, and introduce cooling oil into the through shaft at the end cover position, but the through shaft is always in a high-speed rotating state, so the oil inlet hole and the oil injection hole on the through shaft are always in a state of alignment and misalignment, and reciprocate switching, so the oil feeding resistance is large, and the fluctuation is large, which finally leads to poor cooling effect of the rotor. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to overcome the defects of large fluctuation and large resistance in the oil feeding mode of the through shaft in the coaxial electric drive system in the prior art, so as to provide a coaxial driving device and a vehicle.

[0005] In order to solve the above problems, the present application provides a coaxial driving device, comprising: a housing, a stator and a rotor, the stator and the rotor are arranged in the housing, the housing comprises an end cover, the end cover is provided with a first flow passage, and the end cover is provided with a first hole communicated with the first flow passage; a rotor shaft rotatably arranged in the housing and fixedly connected with the rotor, the rotor shaft has a cavity inside, the cavity penetrates through both ends of the rotor shaft, the rotor shaft is provided with a second hole communicated with the cavity and the rotor; a through shaft is arranged in the cavity of the rotor shaft, and one end of the through shaft extends to the end cover, the through shaft is provided with a second flow passage, and the through shaft is provided with a third hole and a fourth hole communicated with the second flow passage, the third hole is communicated with the first hole, and the fourth hole is communicated with the cavity, wherein a buffer groove is arranged on the surface of the end cover and / or the surface of the through shaft at the matching position of the end cover and the through shaft, and the first hole and the third hole are both communicated with the buffer groove.

[0006] Optionally, the buffer groove is annular, and the buffer groove extends along the circumferential direction.

[0007] Optionally, the end cover is provided with a rotating shaft hole, one end of the penetrating shaft is arranged in the rotating shaft hole, and the buffer groove is arranged on the hole wall of the rotating shaft hole.

[0008] Optionally, two groups of sealing structures are arranged between the end cover and the penetrating shaft, and the two groups of sealing structures are located on the two sides of the buffer groove in the axial direction.

[0009] Optionally, the fourth holes are a plurality of holes, at least part of the fourth holes are arranged in a staggered manner along the axial direction of the penetrating shaft, and / or at least part of the fourth holes are arranged in a staggered manner along the circumferential direction of the penetrating shaft.

[0010] Optionally, the inner wall of the cavity is provided with a limiting groove, the second hole is arranged at the groove bottom of the limiting groove, and the fourth hole is located within the range of the limiting groove in the axial direction of the penetrating shaft.

[0011] Optionally, the limiting groove is annular, and the limiting groove extends along the circumferential direction of the rotor shaft.

[0012] Optionally, the rotor comprises a cooling channel, the second hole comprises a first hole group, and the first hole group is in communication with the cooling channel.

[0013] Optionally, the second hole further comprises a second hole group, the second hole group is located on the outer side of the rotor, and the first hole group and the second hole group are arranged in a staggered manner along the axial direction of the rotor shaft.

[0014] The application also provides a vehicle comprising the coaxial driving device.

[0015] The application has the following advantages:

[0016] According to the technical scheme of the application, the cooling medium is introduced from the first flow passage of the end cover, and then enters the penetrating shaft through the first hole and the third hole, and then the cooling medium is introduced to the rotor through the second flow passage, the third hole and the first hole, so as to cool the rotor. During the operation of the coaxial driving device, the third hole rotates at a high speed relative to the first hole, and switches between the aligned state and the staggered state. After the cooling medium flows out of the first hole, it can be buffered in the buffer groove and fill the buffer groove, and the pressure in the buffer groove can be increased. Therefore, in the case that the penetrating shaft rotates at a high speed and the first hole and the third hole are staggered, the cooling medium can also flow into the third hole, and the cooling medium discharged from the second hole has high pressure and small pressure fluctuation, thereby ensuring the cooling effect of the rotor. Therefore, the technical scheme of the application solves the defects of large fluctuation and large resistance of the oil inlet mode of the penetrating shaft in the coaxial electric drive system in the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the specific embodiments of the present application or the prior art, the accompanying drawings needed to be used in the description of the specific embodiments or the prior art will be briefly introduced. Obviously, the accompanying drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0018] Figure 1 A structural schematic diagram of a coaxial driving device of the present application is shown.

[0019] Figure 2 A structural schematic diagram of a coaxial driving device of the present application is shown. Figure 1 A sectional view schematic diagram of a coaxial driving device of the present application is shown.

[0020] Figure 3 A structural schematic diagram of a coaxial driving device of the present application is shown. Figure 2 A structural schematic diagram of an end cover position of a coaxial driving device of the present application is shown.

[0021] Figure 4 A structural schematic diagram of a second hole of a coaxial driving device of the present application is shown. Figure 2

[0022] A structural schematic diagram of an end cover of a coaxial driving device of the present application is shown. Figure 5 Figure 1 A sectional view schematic diagram of an end cover of a coaxial driving device of the present application is shown.

[0023] Figure 6 Figure 5 A structural schematic diagram of a rotor shaft of a coaxial driving device of the present application is shown.

[0024] Figure 7 A sectional view schematic diagram of a rotor shaft of a coaxial driving device of the present application is shown. Figure 1

[0025] A structural schematic diagram of a through shaft of a coaxial driving device of the present application is shown. Figure 8 Figure 7 A sectional view schematic diagram of a through shaft of a coaxial driving device of the present application is shown.

[0026] Figure 9 Figure 1 A structural schematic diagram of a through shaft of a coaxial driving device of the present application is shown.

[0027] Figure 10 A sectional view schematic diagram of a through shaft of a coaxial driving device of the present application is shown. Figure 9

[0028] Explanation of reference signs:

[0029] ​​​​​10, stator; 20, rotor; 30, end cover; 31, first flow passage; 32, first hole; 33, rotating shaft hole; 40, rotor shaft; 41, cavity; 411, limiting groove; 42, second hole; 421, first hole group; 422, second hole group; 50, through shaft; 51, second flow passage; 52, third hole; 53, fourth hole; 60, buffer groove; 70, sealing structure. DETAILED DESCRIPTION

[0030] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0031] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0032] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0033] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0034] For example, Figures 1 to 10As shown, the coaxial driving device according to the embodiment of the present application comprises a housing, a stator 10, a rotor 20, a rotor shaft 40 and a through shaft 50. Among them, the stator 10 and the rotor 20 are both arranged in the housing, and the housing comprises an end cover 30, the end cover 30 is provided with a first flow channel 31, and the end cover 30 is provided with a first hole 32 in communication with the first flow channel 31. The rotor shaft 40 is rotatably arranged in the housing and fixedly connected with the rotor 20. The rotor shaft 40 has a cavity 41 inside, the cavity 41 penetrates through both ends of the rotor shaft 40, and the rotor shaft 40 is provided with a second hole 42 in communication with the cavity 41 and the rotor 20. The through shaft 50 is arranged in the cavity 41 of the rotor shaft 40, and one end of the through shaft 50 extends to the end cover 30. The through shaft 50 is provided with a second flow channel 51, and the through shaft 50 is provided with a third hole 52 and a fourth hole 53 in communication with the second flow channel 51, the third hole 52 is in communication with the first hole 32, and the fourth hole 53 is in communication with the cavity 41.

[0035] Further, at the matching position of the end cover 30 and the through shaft 50, a buffer groove 60 is arranged on the surface of the end cover 30 and / or the surface of the through shaft 50, and the first hole 32 and the third hole 52 are both in communication with the buffer groove 60.

[0036] By using the technical scheme of the embodiment, the cooling medium is introduced from the first flow channel 31 of the end cover 30, and enters the through shaft 50 through the first hole 32 and the third hole 52, and then the cooling medium is introduced to the rotor 20 through the second flow channel 51, the third hole 52 and the first hole 32, so as to cool the rotor 20. During the operation of the coaxial driving device, the third hole 52 rotates at high speed relative to the first hole 32, and reciprocally switches between the aligned state and the misaligned state. After the cooling medium flows out of the first hole 32, it can be buffered in the buffer groove 60 and fill the buffer groove 60, and the pressure in the buffer groove 60 is easy to increase. Therefore, in the case that the through shaft 50 rotates at high speed and the first hole 32 and the third hole 52 are misaligned, the cooling medium can also flow into the third hole 52, and the cooling medium discharged from the second hole 42 can have high pressure and small pressure fluctuation, so as to ensure the cooling effect of the rotor 20. Therefore, the technical scheme of the embodiment solves the defects of large fluctuation and large resistance of the through shaft oil inlet mode in the coaxial electric drive system in the prior art.

[0037] It should be noted that the cooling medium in the embodiment is cooling lubricating oil, of course, the cooling medium can also be other liquids, gases and the like.

[0038] The coaxial driving device comprises a housing, that is, the shell of the motor, and the housing comprises an end cover 30 arranged at the axial end position of the shell. From the above description, it can be seen that the end cover 30 is arranged at the axial end position of the shell, and the first flow channel 31 is arranged on the end cover 30. Figure 5 And Figure 6It can be seen that the end cover 30 is roughly in the shape of an umbrella. The first flow passage 31 is arranged in the end cover 30. Figure 5 It can be seen that the first flow passage 31 forms an inlet on the outer surface of the end cover 30, through which the cooling medium can enter the first flow passage 31.

[0039] From Figure 6 It can be seen that the inner side of the end cover 30 is provided with a first hole 32, which is in communication with the first flow passage 31, so that the cooling medium can be discharged from the end cover 30 through the first hole 32.

[0040] Further, the housing is provided with the stator 10 and the rotor 20, which can rotate around its axis after being energized, thereby providing driving force. At the same time, a large amount of heat will be generated during the high-speed rotation of the rotor 20, so the rotor 20 needs to be cooled to ensure the performance of the motor.

[0041] From Figure 2 It can be seen that the rotor shaft 40 is arranged in the housing, the inner hole of the rotor 20 is sleeved on the outer side of the rotor shaft 40, and the rotor shaft 40 is fixedly arranged in the inner hole of the rotor 20. Therefore, when the rotor 20 rotates at high speed, the rotor shaft 40 can rotate synchronously.

[0042] From Figure 7 And Figure 8 It can be seen that the rotor shaft 40 has an inner cavity, which penetrates through both ends of the rotor shaft 40, so that the rotor shaft 40 is in the form of a hollow shaft with both ends open. The second hole 42 is further arranged on the rotor shaft 40, which penetrates through the inside and outside of the rotor shaft 40. The inner side of the second hole 42 is in communication with the cavity 41, and the outer side is in communication with the rotor 20.

[0043] The "outer side of the second hole 42 is in communication with the rotor 20" means that the cooling medium discharged from the second hole 42 can flow into the inside or the outer surface of the rotor 20, thereby cooling the rotor 20. It includes that the second hole 42 is in communication with the cooling flow passage of the rotor 20, or the second hole 42 is in communication with the outer side space of the rotor 20.

[0044] From Figure 2 It can be seen that the through shaft 50 is arranged in the cavity 41 of the rotor shaft 40, and the two are coaxially arranged. The two ends of the through shaft 50 pass through the two ends of the rotor shaft 40, and the Figure 2 In the direction shown, the right end of the through shaft 50 passes out of the end cover 30.

[0045] During the actual operation of the coaxial driving device, the rotor 20 drives the rotor shaft 40 to rotate, and then the Figure 2The left position shown, the rotor shaft 40 and through the shaft 50 through the transmission mechanism connection. That is, the rotation of the rotor shaft 40 (or the rotation of the rotor 20) through the transmission to the through shaft 50, that is, the rotor shaft 40 and the through shaft 50 are not synchronous rotation. The rotation of the through shaft 50 is output to the wheel, thereby realizing the drive of the vehicle.

[0046] Further, from Figure 9 And Figure 10 It can be seen that the through shaft 50 is provided with a second flow channel 51, and the second flow channel 51 is specifically provided at the central axis position of the through shaft 50 and extends along the axial direction of the through shaft 50. And the second flow channel 51 penetrates the Figure 2 The right end face shown, thereby facilitating processing. The through shaft 50 is also provided with a third hole 52 and a fourth hole 53, wherein the third hole 52 and the fourth hole 53 both extend along the radial direction of the through shaft 50, both of which communicate the second flow channel 51 and the outside of the through shaft 50. And the third hole 52 and the fourth hole 53 are arranged in a circumferential direction.

[0047] From Figure 6 It can be seen that the inner side of the end cover 30 is provided with a buffer groove 60, and the first hole 32 is located in the buffer groove 60, that is, the first hole 32 communicates with the buffer groove 60.

[0048] When the relationship between the various components after assembly, such as Figure 3 And Figure 4 The third hole 52 communicates with the buffer groove 60, and the fourth hole 53 communicates with the cavity 41.

[0049] Based on the above structure, the following describes the flow mode of the cooling medium in the coaxial drive device in this embodiment:

[0050] 1. The cooling medium is introduced from the first flow channel 31 into the end cover 30, and then discharged from the first hole 32 into the buffer groove 60;

[0051] 2. The cooling medium in the buffer groove 60 enters the second flow channel 51 inside the through shaft 50 through the third hole 52;

[0052] 3. The cooling medium enters the cavity 41 through the fourth hole 53;

[0053] 4. The cooling medium is discharged from the second hole 42 to the rotor 20, thereby cooling the rotor 20.

[0054] In the above structure, those skilled in the art can understand that during the rotation of the through shaft 50, the third hole 52 rotates at high speed relative to the first hole 32, and the two reciprocate in the aligned and staggered state, which will bring the following two problems:

[0055] 1. During the rotation of the through-shaft 50, the cooling medium can flow smoothly from the end cover 30 into the through-shaft 50 only when the third hole 52 and the first hole 32 are completely aligned. In other states (when the third hole 52 and the first hole 32 are partially aligned or completely misaligned), the cooling medium has a large flow resistance, so the flow rate of the cooling medium discharged at the second hole 42 fluctuates greatly.

[0056] 2. Since the apertures of the third hole 52 and the first hole 32 are relatively small, they can only be aligned for a very short time during the rotation of the through-shaft 50. At other times, the cooling medium has a large flow resistance. Therefore, from an overall perspective, the pressure of the cooling medium discharged from the second hole 42 is relatively small, that is, the flow rate is relatively small, and the cooling effect on the rotor 20 is relatively weak.

[0057] To address these two issues, this embodiment incorporates a buffer tank 60. Specifically, after the coolant is discharged from the first hole 32, it is first filled into the buffer tank 60. Once the buffer tank 60 is filled with coolant, the pressure of the coolant increases within the buffer tank 60, enhancing its fluidity. Therefore, regardless of whether the third hole 52 and the first hole 32 are fully aligned, partially aligned, or misaligned, the coolant can flow smoothly into the third hole 52. Consequently, the coolant discharged from the second hole 42 maintains a stable and high flow rate, providing enhanced cooling for the rotor 20.

[0058] from Figure 3 From the content shown, those skilled in the art can understand that, in the two opposite surfaces of the end cover 30 and the through shaft 50, the buffer groove 60 can be set on the surface of the end cover 30, or on the surface of the through shaft 50, or the buffer groove 60 can be set on the surfaces of both the end cover 30 and the through shaft 50.

[0059] In fact, as long as both the first hole 32 and the third hole 52 are connected to the buffer tank 60 , the cooling medium can be stored in the buffer tank 60 before entering the third hole 52 .

[0060] like Figure 3 and Figure 6 As shown, in the technical solution of this embodiment, the buffer groove 60 is annular and extends along the circumferential direction.

[0061] Specifically, the annular buffer groove 60 ensures that the third hole 52 is within the range of the buffer groove 60 no matter to which angle the through shaft 50 rotates, thereby ensuring that the cooling medium can smoothly enter the third hole 52 after being pressurized in the buffer groove 60 .

[0062] from Figure 9It can also be seen that the third holes 52 are arranged in a plurality, and the plurality of third holes 52 are uniformly distributed along the circumference. In this way, after the cooling medium is discharged from the first holes 32, the cooling medium can enter the through shaft 50 in a shorter path, thereby reducing the flow resistance of the cooling medium and increasing the flow of the cooling medium discharged from the second holes 42.

[0063] Further, the plurality of third holes 52 are at the same axial position, and this arrangement ensures that the plurality of third holes 52 can be within the range of the buffer groove 60 during rotation of the through shaft 50, and the buffer groove 60 does not have to have a large width.

[0064] Optionally, the third holes 52 can be arranged in three, four, five, etc.

[0065] In addition, uniformly distributing the plurality of third holes 52 along the circumference ensures that the through shaft 50 has a stable center of mass, thereby ensuring that the through shaft 50 does not shake significantly during high-speed rotation.

[0066] From Figure 3 It can also be seen that the cross-sectional shape of the buffer groove 60 includes a bottom side and two side sides, one of which is a straight side and the other is an inclined side. Further, the side of the cross-sectional shape of the buffer groove 60 facing the rotor 20 is an inclined side, and the inclined side is inclined towards the rotor 20.

[0067] As shown in Figure 3 , Figure 5 and Figure 6 , in the technical solution of the present embodiment, the end cover 30 is provided with a shaft hole 33, one end of the through shaft 50 is arranged in the shaft hole 33, and the buffer groove 60 is arranged on the hole wall of the shaft hole 33.

[0068] Specifically, the through shaft 50 passes through the shaft hole 33, thereby passing through the end cover 30. From Figure 6 It can be seen that the shaft hole 33 has a plurality of stepped surfaces, and the above-mentioned buffer groove 60 is arranged on the surface of the shaft hole 33 closest to the through shaft 50. That is Figure 6 In the above-mentioned buffer groove 60, the wall surface on the left side of the shaft hole 33. In this way, the gap between the through shaft 50 and the shaft hole 33, and the buffer groove 60 form a small volume chamber. When the cooling medium flows into the chamber, the chamber can be quickly filled, and the pressure of the cooling medium is increased, thereby increasing the pressure of the cooling medium discharged from the second hole 42.

[0069] As shown in Figure 3 and Figure 6 , in the technical solution of the present embodiment, two sets of sealing structures 70 are arranged between the end cover 30 and the through shaft 50, and the two sets of sealing structures 70 are respectively located on the two sides of the buffer groove 60 in the axial direction.

[0070] Specifically, the two sets of sealing structures 70, the outer surface of the through shaft 50, the inner surface of the rotating shaft hole 33 and the buffer groove 60 form the above-mentioned closed chamber. Further, the sealing structure 70 comprises a sealing ring, the outer surface of the through shaft 50 is provided with a mounting ring groove, and the sealing ring is arranged in the mounting ring groove. When the through shaft 50 is mounted in the rotating shaft hole 33, the sealing ring is compressed and deformed.

[0071] Further, the mounting ring groove is two, and the two mounting ring grooves are respectively located on both sides of the third hole 52 in the axial direction, and the two mounting ring grooves are respectively used for mounting two sealing rings.

[0072] As shown in Figure 9 In the technical scheme of the embodiment, the fourth hole 53 is a plurality of fourth holes, and at least part of the fourth holes 53 are arranged in a staggered manner along the axial direction of the through shaft 50; and / or, at least part of the fourth holes 53 are arranged in a staggered manner along the circumferential direction of the through shaft 50.

[0073] Because the torque transmitted by the through shaft 50 is large, when the fourth hole 53 is opened on the through shaft 50, the strength of the through shaft 50 needs to be ensured to meet the requirements.

[0074] Specifically, a plurality of fourth holes 53 are arranged in the embodiment, thereby increasing the number of channels for the cooling medium to flow out of the through shaft 50. In the embodiment, the plurality of fourth holes 53 are arranged in a staggered manner in the axial direction or the circumferential direction, thereby preventing too many fourth holes 53 from being arranged at a specific position of the through shaft 50, which causes the strength of the position to be relatively weak.

[0075] From Figure 9 and Figure 10 It can be seen that the plurality of fourth holes 53 in the embodiment are divided into two groups, and the two groups of fourth holes 53 are arranged in a staggered manner along the axial direction of the through shaft 50. Further, each group of fourth holes 53 comprises a plurality of fourth holes 53, and the plurality of fourth holes 53 in the same group are arranged in a staggered manner along the circumferential direction of the through shaft 50, and the fourth holes 53 in different groups are arranged in a staggered manner along the circumferential direction of the through shaft 50. In this way, it can be ensured that there is no region of the through shaft 50 where too many fourth holes 53 are arranged.

[0076] In some embodiments not shown, the arrangement mode of the plurality of fourth holes 53 can be determined by the person skilled in the art according to actual needs. As long as the region of the through shaft 50 where too many fourth holes 53 are arranged is avoided, and the centroid of the through shaft 50 is stable, the arrangement mode can be determined.

[0077] As shown in Figure 4 and Figure 8 In the technical scheme of the embodiment, the inner wall of the cavity 41 is provided with a limiting groove 411, the second hole 42 is arranged at the groove bottom of the limiting groove 411, and the fourth hole 53 is located within the range of the limiting groove 411 along the axial direction of the through shaft 50.

[0078] Specifically, the cooling medium is flung from the fourth hole 53 to the inner wall of the cavity 41 during the rotation of the shaft 50. The limiting groove 411 functions to limit the cooling medium within the range enclosed by the limiting groove 411, i.e. to limit the cooling medium to the position near the second hole 42. In this way, the adhesion of the cooling medium to the wall surface far from the second hole 42 is reduced, thereby reducing the loss of the cooling medium and improving the cooling efficiency of the multi-rotor 20.

[0079] As shown in Figure 4 and Figure 8 , the limiting groove 411 is annular, and extends along the circumference of the rotor shaft 40. In this way, the limiting groove 411 can limit the cooling medium to the position near the second hole 42 in the entire circumference.

[0080] As shown in Figure 4 and Figure 8 , in the technical solution of the embodiment, the rotor 20 comprises a cooling channel, and the second hole 42 comprises a first hole group 421, which is in communication with the cooling channel.

[0081] Specifically, the cooling medium flung from the first hole group 421 can enter the cooling channel in the rotor 20, thereby cooling the interior of the rotor 20.

[0082] As shown in Figure 4 and Figure 8 , in the technical solution of the embodiment, the second hole 42 further comprises a second hole group 422, which is located on the outer side of the rotor 20, and the first hole group 421 and the second hole group 422 are arranged in a staggered manner along the axial direction of the rotor shaft 40.

[0083] Specifically, the cooling medium flung from the second hole group 422 can be flung to the outer surface of the rotor 20, i.e. to cool the winding on the rotor 20.

[0084] Optionally, the first hole group 421 comprises a plurality of second holes 42, and the plurality of second holes 42 of the first hole group 421 are arranged in a spaced manner along the circumferential direction of the rotor shaft 40.

[0085] Optionally, the second hole group 422 comprises a plurality of second holes 42, and the plurality of second holes 42 of the second hole group 422 are arranged in a spaced manner along the circumferential direction of the rotor shaft 40.

[0086] The application also provides a vehicle, and an embodiment of the vehicle according to the application comprises the coaxial driving device described above.

[0087] Optionally, the vehicle is a new energy electric vehicle.

[0088] Obviously, the above embodiments are merely example for clearly illustrating but not limitation to the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments need not and can not be enumerated. The obvious changes or variations derived from the above description are still within the protection scope of the present application.

Claims

1. A coaxial drive device characterized by comprising: The utility model relates to a kind of motor, including: Shell, stator (10) and rotor (20), the stator (10) and the rotor (20) are arranged in the shell, the shell includes end cover (30), first overflow passage (31) is arranged on the end cover (30), first hole (32) is arranged on the end cover (30) and is communicated with the first overflow passage (31); Rotor shaft (40) is rotatably arranged in the shell and is fixedly connected with the rotor (20), the rotor shaft (40) has cavity (41) inside, the cavity (41) is through the both ends of the rotor shaft (40), second hole (42) is arranged on the rotor shaft (40), and the second hole (42) is communicated with the cavity (41) and the rotor (20) place; Through shaft (50) is arranged in the cavity (41) of the rotor shaft (40), and one end of the through shaft (50) extends to the end cover (30), second overflow passage (51) is arranged in the through shaft (50), third hole (52) and fourth hole (53) are arranged on the through shaft (50) and are communicated with the second overflow passage (51), the third hole (52) is communicated with the first hole (32), and the fourth hole (53) is communicated with the cavity (41), Wherein, the end cover (30) and the cooperation of the through shaft (50), the surface of the end cover (30) and / or the surface of the through shaft (50) is provided with buffer groove (60), and the first hole (32) and the third hole (52) are communicated with the buffer groove (60).

2. The coaxial drive device of claim 1, wherein The buffer groove (60) is annular, and the buffer groove (60) extends along the circumference.

3. A coaxial drive device according to claim 1 or 2, characterized in that The end cover (30) is provided with shaft hole (33), one end of the through shaft (50) is arranged in the shaft hole (33), and the buffer groove (60) is arranged on the hole wall of the shaft hole (33).

4. The coaxial drive device of claim 3, wherein Two groups of sealing structures (70) are arranged between the end cover (30) and the through shaft (50), and the two groups of sealing structures (70) are located on the two sides of the buffer groove (60) in the axial direction.

5. The coaxial drive device according to claim 1 or 2, characterized by The fourth hole (53) is a plurality of, and at least part of the fourth hole (53) is arranged in the axial direction of the through shaft (50) and / or at least part of the fourth hole (53) is arranged in the circumferential direction of the through shaft (50).

6. The coaxial drive device according to claim 1 or 2, characterized by The inner wall of the cavity (41) is provided with limiting groove (411), and the second hole (42) is arranged at the groove bottom of the limiting groove (411), and in the axial direction of the through shaft (50), the fourth hole (53) is located in the range of the limiting groove (411).

7. The coaxial drive device of claim 6, wherein The limiting groove (411) is annular, and the limiting groove (411) extends along the circumferential direction of the rotor shaft (40).

8. The coaxial drive device according to claim 1 or 2, characterized by The rotor (20) includes a cooling channel, and the second hole (42) includes a first hole group (421), and the first hole group (421) is communicated with the cooling channel.

9. The coaxial drive device of claim 8, wherein, The second hole (42) further comprises a second hole group (422) located at the outer side of the rotor (20), and the first hole group (421) and the second hole group (422) are arranged in axial misalignment along the rotor shaft (40).

10. A vehicle characterized by comprising: A coaxial drive comprising the coaxial drive of any one of claims 1 to 9.

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