WO2020181466A1

WO2020181466A1 - Hub motor driving system and motor vehicle

Info

Publication number: WO2020181466A1
Application number: PCT/CN2019/077690
Authority: WO
Inventors: 饶玲军
Original assignee: 舍弗勒技术股份两合公司; 饶玲军
Priority date: 2019-03-11
Filing date: 2019-03-11
Publication date: 2020-09-17

Abstract

The present invention relates to the field of motor vehicles such as electric vehicles, and in particular, to a hub motor driving system for a motor vehicle and a motor vehicle. The hub motor driving system changes positions of a radial beating and a sealing assembly between a housing body and a rotor spider, so that it would easy for a lubricant to reach the radial bearing and the sealing assembly under the action of a centrifugal force, and an adequate space can be provided for storing more lubricants to improve the stock of the lubricant.

Description

Wheel hub motor drive system and motor vehicle

Technical field

The present invention relates to the field of motor vehicles such as electric vehicles, and in particular to an in-wheel motor drive system for motor vehicles and a motor vehicle including the in-wheel motor drive system.

Background technique

In the prior art, new energy vehicles such as electric vehicles integrate drive motors, planetary gear reducers, wheel bearings and braking systems in the wheel space to form a wheel hub motor drive system, where the drive motor can directly drive the wheels No transmission and drive shaft are required.

Figure 1a shows the structure of a prior art in-wheel motor drive system. As shown in Figure 1a, the in-wheel motor drive system includes a housing assembly (including a housing body 1 and a housing cover 2) assembled together, a drive motor 3, a rotor bracket 4, a sealing assembly 5, a radial bearing 6, a planetary Gear reducer 7, (axial) thrust bearing 8, output shaft 9, etc. The sealing assembly 5 is arranged between the housing main body 1 and the rotor support 4 for sealing the installation space in the housing assembly. The radial bearing 6 is arranged between the housing main body 1 and the rotor support 4 and located at the radial inner side of the sealing assembly 5, and the radial bearing 6 is used to support the rotor support 4 so that the rotor support 4 can rotate relative to the housing main body 1. The thrust bearing 8 is arranged between the rotor carrier 4 and the planet carrier of the planetary gear reducer 7 and is used to enable the planet carrier to rotate relative to the rotor carrier 4.

In the prior art in-wheel motor drive system with the above-mentioned structure, in terms of the continuous reliability of the performance and function of the in-wheel motor drive system, the sealing assembly 5, the radial bearing 6, the planetary gear reducer 7 and the thrust bearing The lubrication of 8 is important, especially the lubrication of the bearing between the pin shaft of the planetary gear carrier in the planetary gear reducer 7 and the planetary gear under the high-speed load state.

However, on the one hand, in the prior art in-wheel motor drive system, the seal assembly 5, the radial bearing 6, the planetary gear reducer 7 and the thrust bearing 8 are not sufficiently lubricated due to structural limitations. On the other hand, due to space constraints, the amount of oil that can be stored in the in-wheel motor drive system is insufficient, and the molecular chain of the lubricating oil will be damaged by gear meshing, and the amount of lubricating oil is far unable to meet the service life of the planetary gear reducer 7. Needs. Specifically, as shown in Figure 1b, when the liquid level of the lubricating oil is 45mm below the position of the center axis of the output shaft 9 of the in-wheel motor drive system, the amount of lubricating oil in the in-wheel motor drive system is only 89ml, which cannot To meet the service life of the in-wheel motor drive system, the replacement of lubricating oil must be planned.

Summary of the invention

The present invention was made based on the above-mentioned defects of the prior art. An object of the present invention is to provide a new type of in-wheel motor drive system, which can improve the lubrication effect of the radial bearing and seal assembly between the housing main body and the rotor support and is compared with the prior art Can increase the stock of lubricating oil. The invention also provides a motor vehicle including the in-wheel motor drive system.

In order to achieve the above-mentioned purpose of the invention, the present invention adopts the following technical solutions.

The present invention provides an in-wheel motor drive system as follows, which includes a housing assembly including a housing body and a housing cover assembled together in an axially opposed manner, the housing An installation space is formed inside the assembly, the housing body includes an axial portion of the housing body extending substantially along the axial direction, a drive motor, the drive motor is housed in the installation space, and the drive motor includes A stator fixed to the housing body and a rotor located radially inside the stator and capable of rotating relative to the stator; and a rotor support that supports the rotor from the radial inside and is fixed to the rotor The rotor support includes a first rotor support axial portion extending substantially along the axial direction and fixed to the rotor, the first rotor support axial portion being located radially outside of the housing main body axial portion, The in-wheel motor drive system further includes a first bearing and a seal provided in the radial gap between the radially inner surface of the axial portion of the first rotor support and the radially outer surface of the axial portion of the housing body Components.

Preferably, the rotor support further includes a rotor support radial portion extending from the first rotor support axial portion in a radial direction toward a radial inner side, and the housing main body axial portion includes an axially facing The free end of the rotor support radial portion and spaced apart from the rotor support radial portion, the first bearing is positioned closer to the free end than the seal assembly.

Preferably, the axial portion of the first rotor support is formed with a thickened portion whose radial thickness is greater than that of the rest, and the first bearing is located on the radially inner side of the thickened portion and the axial portion of the housing body. Between the radially outer sides.

Preferably, the in-wheel motor drive system further includes a planetary gear reducer located radially inward of the axial portion of the housing main body, and the planetary gear reducer includes a second bearing located between the planetary carrier and the planetary gears , And the planetary gear carrier includes a pin shaft penetrating through the planetary gear, an oil channel communicating with the second bearing is formed inside the pin shaft, and the planetary gear reducer further includes The oil passage starts from an oil guide ring extending toward the rotor support, so that lubricating oil from the radially inner side of the oil guide ring can be guided into the oil guide passage.

More preferably, the rotor support further includes a second rotor support axial portion extending substantially in the axial direction and located at the radial inner side of the rotor support radial portion of the rotor support, and the planetary carrier further includes The pin shaft has end plates at both axial ends, and the in-wheel motor drive system further includes a thrust bearing provided between the axial portion of the second rotor support and the end plate, and the thrust bearing is located on the The radial inner side of the oil guide ring.

More preferably, an axial side surface of the radial portion of the rotor support facing the planetary gear reducer extends in the radial direction without protrusions in the axial direction.

More preferably, in the axial direction, the interval between the oil guide ring and the radial portion of the rotor support is not less than the interval between the axial portion of the housing main body and the radial portion of the rotor support.

More preferably, the oil guide ring includes an oil guide ring main body extending substantially along the axial direction, and a cross-sectional profile of a portion of the radially inner peripheral surface of the oil guide ring main body away from the planetary gear reducer is formed to face A curved shape bent radially inside.

More preferably, a part of the main body of the oil guide ring is inserted into the pin shaft and installed with the pin shaft through interference fit.

The present invention also provides the following motor vehicle, which includes the in-wheel motor drive system described in any one of the above technical solutions.

By adopting the above technical solutions, the present invention provides a new type of in-wheel motor drive system and a motor vehicle including the in-wheel motor drive system. The in-wheel motor drive system changes the radial bearing and seal between the housing body and the rotor support. The position of the component makes it easy for the lubricating oil to reach the radial bearing and the sealing component under the action of centrifugal force and makes it possible to free up enough space for storing more lubricating oil to increase the amount of lubricating oil.

Description of the drawings

Fig. 1a is a schematic cross-sectional view of an in-wheel motor drive system according to the prior art; Fig. 1b is an explanatory diagram for explaining the amount of lubricating oil in the in-wheel motor drive system in Fig. 1a.

Fig. 2a is a schematic cross-sectional view of an in-wheel motor drive system according to an embodiment of the present invention; Fig. 2b is an enlarged schematic view of a partial structure of the in-wheel motor drive system in Fig. 2a.

Fig. 3a is a schematic sectional view of the partial structure of the planetary gear reducer of the in-wheel motor drive system in Fig. 2a; Fig. 3b is a perspective view of the partial structure of the planetary gear reducer of the in-wheel motor drive system in Fig. 2a.

Description of reference signs

1 Housing body 11 Axial part of housing body 2 Housing cover 3 Drive motor 31 Rotor 4 Rotor support 41 First rotor support axial part 41 T thickened part 42 Rotor support radial part 43 Second rotor support axial part 5 Seal assembly 6 Radial bearing (first bearing) 7 Planetary gear reducer 71 Sun gear shaft 72 Planetary gear 73 Planetary gear carrier 731 Pin shaft 732 End plate 74 Oil guide ring 75 Pin shaft bearing (second bearing) 8 Thrust bearing 9 Output axis

S installation space G1 first gap G2 second gap A axis R radial.

detailed description

The specific embodiments of the present invention will be described in detail below with reference to the drawings of the specification. In this specification, "axial", "radial" and "circumferential" refer to the axial, radial and circumferential directions of the housing assembly (including the housing body and the housing cover) of the in-wheel motor drive system, respectively. One side in the axial direction refers to the left side in FIGS. 2a to 3a, and the other side in the axial direction refers to the right side in FIGS. 2a to 3a.

Figures 2a and 2b show an in-wheel motor drive system according to an embodiment of the present invention. Except for the partial structure of the in-wheel motor drive system shown in FIG. 2b, other structures of the in-wheel motor drive system may be the same as the prior art in-wheel motor drive system in FIG.

As shown in Figures 2a and 2b, the in-wheel motor drive system according to an embodiment of the present invention includes a housing assembly (including a housing body 1 and a housing cover 2) assembled together, a drive motor 3, a rotor bracket 4, Seal assembly 5, radial bearing 6, planetary gear reducer 7, thrust bearing 8 and output shaft 9.

In this embodiment, the housing assembly constituted by the housing main body 1 and the housing cover 2 has a substantially cylindrical shape as a whole. The housing main body 1 is located on one axial side of the housing cover 2 and is formed with an opening facing the other axial side. The housing cover 2 is opposed to the housing body 1 in the axial direction A and is assembled with the housing body 1 in such a way as to cover the opening of the housing body 1, so that the housing body 1 and the housing cover 2 surround and form an installation space S. The bottom of the housing body 1 opposite to the opening is formed in a bent shape and the housing cover 2 is also formed in a bent shape, so that the size of the installation space S between the housing body 1 and the housing cover 2 in the axial direction A Decrease from the radial outside toward the radial inside.

Further, the radially inner portion of the housing body 1 is formed as a housing body axial portion 11 extending substantially along the axial direction, and the housing body axial portion 11 is formed with the first rotor support axial portion 41 described below. Relatively multi-step structure.

In this embodiment, the entire drive motor 3 is housed in the installation space S of the housing assembly. The driving motor 3 includes a stator and a rotor 31 each having an annular shape.

Specifically, the stator is located at the radially inner side of the housing body 1 and is fixed relative to the housing body 1. A cooling assembly is preferably provided between the stator and the outer periphery of the housing body 1 to reduce the work of the stator in the drive motor 3. The temperature in the process.

The rotor 31 is located on the radially inner side of the stator and is opposed to the stator in the radial direction R. The rotor 31 can rotate relative to the stator, so that when the stator generates a magnetic field, the rotor 31 can rotate in the magnetic field.

In this embodiment, the rotor holder 4 is used to support the rotor 31 and has a cylindrical shape as a whole. The rotor support 4 includes a first rotor support axial portion 41, a rotor support radial portion 42 and a second rotor support axial portion 43 which are connected to each other.

Specifically, the first rotor support axial portion 41 extends substantially along the axial direction A. The first rotor support axial portion 41 is located on the radially outer side of the casing main body axial portion 11 and a radial gap is formed in the radial direction R between the first rotor support axial portion 41 and the casing main body axial portion 11. The first rotor support axial portion 41 is fixed to the rotor 31 from the radial inner side to support the rotor 31. The length of the first rotor support axial portion 41 in the axial direction A is substantially equal to the length of the rotor 31 in the axial direction A. Further, a thickened portion 41T with a relatively large radial thickness is formed at a portion of the first rotor support axial portion 41 for connecting with the rotor support radial portion 42.

The rotor support radial portion 42 extends from the first rotor support axial portion 41 along the radial direction R toward the radial inner side and protrudes from the installation space S of the housing assembly. The radially inner end of the radial portion 42 of the rotor support is used to fix the axial portion 43 of the second rotor support together. In this embodiment, the surface of the axial side of the radial portion 42 of the rotor holder does not have any convex shape, so compared with the structure of the prior art rotor holder in FIG. 1, the structure of the rotor holder 4 is simple and can be A space for storing lubricating oil is vacated at a position on the axial side of the radial portion 42 of the rotor holder.

The second rotor support axial portion 43 extends substantially along the axial direction and is located at the radial inner side of the rotor support radial portion 42. The second rotor support axial portion 43 is used to fix the following sun gear shaft 71 together to drive The sun gear shaft 71 rotates together.

In this embodiment, the seal assembly 5 and the radial bearing 6 are arranged in the radial gap between the radially inner surface of the first rotor support axial portion 41 and the radially outer surface of the housing main body axial portion 11. In this way, compared with the structure of the in-wheel motor drive system of the prior art in FIG. 1, this arrangement can free up more space for storing lubricating oil.

In addition, the axial portion 11 of the housing body includes a free end facing the radial portion 42 of the rotor holder in the axial direction A and spaced apart from the radial portion 42 of the rotor holder. The radial bearing 6 is positioned closer to the free end than the seal assembly 5. position. More specifically, the radial bearing 6 is located between the radially inner surface of the thickened portion 41T and the radially outer surface of the housing main body axial portion 11 including a part of its free end. In this way, after the lubricating oil flows between the axial portion 11 of the housing main body and the axial portion 41 of the first rotor bracket under the action of centrifugal force, the radial bearing 6 can be lubricated first before it reaches the seal assembly 5 and is isolated by the seal assembly 5. Outside the installation space S of the housing assembly.

Further, in order to ensure that lubricating oil can flow between the axial portion 11 of the housing main body and the axial portion 41 of the first rotor support, the free end of the axial portion 11 of the housing main body and the first rotor support axial portion 41 is between A first gap G1 exists in the axial direction A.

In this embodiment, the planetary gear reducer 7 is integrally located outside the installation space S surrounded by the housing body 1 and the housing cover 2, and the planetary gear reducer 7 is integrally arranged on the radial inner side of the stator. 7 is arranged coaxially with the drive motor 3. Further, with additional reference to Figures 3a and 3b, the planetary gear reducer 7 includes a sun gear shaft 71 assembled with each other, a plurality of planet gears 72, a planet gear carrier 73, a ring gear, and a pin shaft mounted on the planet gear carrier. The oil guide ring 74 of the 731 and the pin bearing 75 located between the planetary gear 72 and the planetary carrier 73, the entire planetary gear reducer is arranged on the axial side of the radial portion 42 of the rotor carrier.

Specifically, the sun gear shaft 71 is a hollow shaft and is fixed to the axial portion 43 of the second rotor support.

A plurality of planetary gears 72 are located on the radially outer side of the sun gear shaft 71 and are evenly distributed along the circumferential direction. Each planetary gear 72 is formed with teeth that mesh with the outer teeth of the sun gear shaft 71, so that as the sun gear shaft 71 rotates, each planetary gear 72 can perform rotation around the respective central axis and revolution around the sun gear shaft 71.

The planetary gear carrier 73 is located on the radially outer side of the sun gear shaft 71, and the planetary gear carrier 73 is fixed to the output shaft 9 while mounting a plurality of planetary gears 72. As the planetary gear 72 revolves, the planetary gear carrier 73 can be driven to rotate and the output shaft 9 can be driven to rotate.

Furthermore, the planetary gear carrier 73 further includes a pin shaft 731 penetrating through each planet gear 72, and an oil guide channel is formed in the pin shaft 731 to communicate with the pin shaft bearing 75. The oil guide ring 74 extends from the oil guide passage toward the rotor holder radial portion 42 of the rotor holder 4 so that the oil from the radially inner side of the oil guide ring 74 can be guided into the oil guide passage. The planetary carrier 73 also includes end plates 732 fixed to both axial ends of the pin shaft 731. In this embodiment, preferably, a part of the oil guide ring 74 extends into the oil guide channel and is assembled with the pin shaft 731 through interference fit.

More specifically, the oil guide ring 74 includes an oil guide ring main body extending substantially in the axial direction, and a cross-sectional profile of a part (including a part of the free end) of the radially inner peripheral surface of the oil guide ring main body is formed to be curved toward the radially inner side. In a curved shape, the free end of the oil guide ring body facing the radial portion 42 of the rotor holder forms a hook shape that is bent toward the radial inner side. In this way, it is possible to facilitate the lubricating oil from the radially inner side to flow into the oil guide passage along the radially inner circumferential surface of the oil guide ring 74. Further, in the axial direction A, there is a second gap G2 between the free end of the oil guide ring 74 and the radial portion 42 of the rotor support. The size of the second gap G2 in the axial direction A is not less than the size of the first gap G1 in the axial direction A. In this way, lubricating oil is not prevented from reaching the first gap G1.

The ring gear is located on the radially outer side of the plurality of planetary gears 72 and is fixed to the housing body 1. A track for the revolution of the plurality of planetary gears 72 is formed between the ring gear and the sun gear shaft 71, and the ring gear is formed with the plurality of planetary gears 72 Teeth meshing with teeth.

In this embodiment, the thrust bearing 8 is disposed between the second rotor bracket axial portion 43 and the end plate 732 located on the other side of the axial direction, and the thrust bearing 8 is located on the radial inner side of the oil guide ring 74. In this way, part of the lubricating oil from the oil guide ring 74 will flow into the thrust bearing 8 to improve the lubrication effect of the thrust bearing 8.

In this embodiment, the output shaft 9 is fixed to the planetary carrier 73 so that the driving force/torque from the rotor 31 can be output from the output shaft 9 to the wheels via the rotor carrier 4 and the planetary gear reducer 7 in sequence.

The specific implementation of the in-wheel motor drive system according to the present invention has been described in detail above, but it needs to be supplemented:

I. The in-wheel motor drive system according to the present invention may also include other necessary components that are not described in the foregoing specific embodiments. For example, the in-wheel motor drive system may also include a steering knuckle sleeve, a sensor and a braking system, etc., and the in-wheel motor drive system may also include other necessary sealing components and bearings.

II. Although not explicitly stated in the above specific embodiments, it should be understood that the radial bearing 6 is preferably a ball bearing, and the pin bearing 75 and the thrust bearing 8 are preferably needle bearings.

III. By adopting the above technical solution, when the liquid level of the lubricating oil is 45mm below the position of the center axis of the output shaft 9 of the in-wheel motor drive system according to the present invention, the inventory of the lubricating oil in the in-wheel motor drive system can reach 131ml. This can increase the inventory by almost 50% compared with the prior art in-wheel motor drive system. In this way, the in-wheel motor drive system according to the present invention can improve the lubrication state of each bearing and seal assembly, and more lubricating oil can prolong the service life of the planetary gear reducer.

Claims

A wheel hub motor drive system, which includes:

A housing assembly, the housing assembly includes a housing body and a housing cover assembled together in an axially opposed manner, an installation space is formed inside the housing assembly, and the housing body includes a substantially Along the axially extending axial part of the housing body,

A drive motor, the drive motor being housed in the installation space, the drive motor including a stator fixed relative to the housing body and a rotor located radially inside the stator and capable of rotating relative to the stator; as well as

A rotor support, the rotor support supports the rotor from a radial inner side and is fixed to the rotor, the rotor support includes a first rotor support axial portion extending substantially along the axial direction and fixed to the rotor,

The axial portion of the first rotor bracket is located on the radially outer side of the axial portion of the housing main body, and the in-wheel motor drive system further includes a radially inner surface disposed on the axial portion of the first rotor bracket and the The first bearing and sealing assembly of the radial gap between the radially outer side surfaces of the axial portion of the housing main body.
The in-wheel motor drive system according to claim 1, wherein the rotor support further comprises a rotor support radial portion extending from the first rotor support axial portion in the radial direction toward the radial inner side, the The axial portion of the housing body includes a free end facing the radial portion of the rotor holder in the axial direction and spaced apart from the radial portion of the rotor holder, and the first bearing is positioned closer to the seal assembly. The position of the free end.
The in-wheel motor drive system according to claim 1 or 2, wherein the axial portion of the first rotor support is formed with a thickened portion with a radial thickness greater than the rest, and the first bearing is located at the thickened portion. Between the radially inner surface of the portion and the radially outer surface of the axial portion of the housing body.
The in-wheel motor drive system according to any one of claims 1 to 3, wherein the in-wheel motor drive system further comprises a planetary gear reducer located on the radially inner side of the axial portion of the housing body, so The planetary gear reducer includes a second bearing located between the planetary carrier and the planetary gears, and

The planetary gear carrier includes a pin shaft penetrating through the planetary gears, an oil guide passage communicating with the second bearing is formed inside the pin shaft, and the planetary gear reducer further includes an oil guide passage The oil guide ring extending toward the rotor bracket enables the lubricating oil from the radially inner side of the oil guide ring to be guided into the oil guide passage.
The in-wheel motor drive system according to claim 4, wherein the rotor support further comprises a second rotor support shaft extending substantially along the axial direction and located at the radial inner side of the rotor support radial portion of the rotor support In the forward part, the planetary carrier further includes end plates fixed to both axial ends of the pin shaft, and

The in-wheel motor drive system further includes a thrust bearing provided between the axial portion of the second rotor support and the end plate, and the thrust bearing is located on the radial inner side of the oil guide ring.
The in-wheel motor drive system according to claim 4 or 5, wherein the radial portion of the rotor bracket is along the axial side surface facing the planetary gear reducer in a form without protrusions in the axial direction. Radial extension.
The in-wheel motor drive system according to any one of claims 4 to 6, wherein:

In the axial direction, the interval between the oil guide ring and the radial portion of the rotor support is not less than the interval between the axial portion of the housing main body and the radial portion of the rotor support.
The in-wheel motor drive system according to any one of claims 4 to 7, wherein the oil guide ring comprises an oil guide ring main body extending substantially along the axial direction, and the oil guide ring main body is radially inwardly The cross-sectional profile of a part of the peripheral surface away from the planetary gear reducer is formed in a curved shape curved toward the radially inner side.
The in-wheel motor drive system according to claim 8, wherein a part of the oil guide ring body is inserted into the pin shaft and is installed with the pin shaft through interference fit.
A motor vehicle comprising the in-wheel motor drive system according to any one of claims 1 to 9.