JP2009190440A - In-wheel motor for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-wheel motor for a vehicle in which the inclination of gears in a reduction gear is suppressed, which has less number of parts for a structure to suppress the inclination of the gears, and the size of which in a vehicle lateral direction is maintained. <P>SOLUTION: This in-wheel motor 11 for a vehicle comprises a hub 25 rotatably supporting a wheel 12, a motor housing 13 which supports the hub 25 through a bearing 26 and in which a stator 14 and a rotor 15 are stored, a gear 36 to which the rotation of the rotor 15 is transmitted, and a rotating shaft part 24 for transmitting the rotation of the gear 36 to the hub 25. The rotating shaft part 24 comprises a first shaft part 46 one end of which is fitted to the gear 36, a second shaft part 47 which is disposed in series with the first shaft part 46, the center of which is supported by the bearing 26, and which has the hub 25 at the one end, and a shaft connection member 51 flexibly connecting the second shaft part 47 to the first shaft part 46. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an in-wheel motor for a vehicle that generates a driving force of a wheel within the wheel of the wheel.

Some in-wheel motors are arranged such that a reduction gear is placed out of the wheel in an electric motor in the wheel, and the driving force is transmitted from the reduction gear to the hub that supports the wheel (for example, (See Patent Document 1).
Japanese Patent Laid-Open No. 2006-240429 (page 8, FIG. 2)

However, in the drive unit of Patent Document 1, when the vehicle is turned left or right, if a lateral load generated on the wheels is applied from the hub to the shaft, the shaft bends and moves like a lever. There is a problem that the gear in the reduction gear meshing with the gear may be tilted.
In a reduction gear, the meshing of gears becomes inappropriate, and noise may be generated or durability may be reduced.

The present invention suppresses the inclination of the gear in the speed reducer, improves the durability of the gear in the speed reducer,
It is an object of the present invention to provide an in-wheel motor for a vehicle in which the number of components configured to suppress the inclination of the gear is small, the size in the vehicle width direction is maintained, and the gear noise in the reduction gear is reduced.

  In the invention which concerns on Claim 1, the hub which supports the wheel rotatably, The motor housing which supports a hub via a bearing and accommodates the stator and the rotor, The gear to which rotation of a rotor is transmitted, And an in-wheel motor for a vehicle having a rotating shaft portion that transmits the rotation of the gear to the hub, the rotating shaft portion being in series with the first shaft portion having one end attached to the gear and the first shaft portion. A second shaft portion disposed at the center and supported by a bearing and having a hub disposed at one end thereof; and a shaft coupling member that bendably connects the second shaft portion to the first shaft portion. It is characterized by that.

  The invention according to claim 2 is characterized in that the first shaft portion and the second shaft portion are attached so that the shaft coupling member is disposed radially inward of the rotor.

  In the invention according to claim 3, the motor housing is provided with a bearing fitting portion that fits the bearing and elastically deforms in response to a load applied to the second shaft portion via the hub. .

  In the invention according to claim 1, the rotating shaft portion is arranged in series with the first shaft portion, one end of which is attached to the gear, is supported in the center by the bearing, and the hub is disposed at one end side. And a shaft connecting member that flexibly connects the second shaft portion to the first shaft portion. When a lateral load is applied, the second shaft part can be bent at a desired angle with the shaft coupling member as a fulcrum with respect to the first shaft part, and the lateral load from the wheel can be absorbed and orthogonal to the first shaft part. There is an advantage that the inclination of the gear in the existing reducer can be suppressed.

  Further, when a lateral load from the wheel is applied, the second shaft portion can be bent at a desired angle with the shaft coupling member as a fulcrum with respect to the first shaft portion, and the lateral load from the wheel can be absorbed. There is an advantage that the inclination of the gear in the speed reducer orthogonal to the portion can be suppressed, and the durability of the gear in the speed reducer can be improved.

  Further, the lateral load from the wheel can be absorbed, and it is not necessary to provide an absorption mechanism for absorbing the lateral load from the wheel between the gear and the rotating shaft portion, and the number of parts can be reduced.

  A lateral load from the wheel can be absorbed, and an absorption mechanism provided between the motor housing of the in-wheel motor and the vehicle body can be used, and the number of parts can be reduced.

  In the invention according to claim 2, since the first shaft portion and the second shaft portion are attached so that the shaft coupling member is disposed inward in the radial direction of the rotor, the shaft coupling is performed in the inner space of the rotor. There is an advantage that the member can be accommodated and the size of the in-wheel motor in the vehicle width direction can be maintained.

  In the invention according to claim 3, the motor housing includes a bearing fitting portion that fits the bearing and elastically deforms in response to a load applied to the second shaft portion via the hub. When a lateral load from the wheel, such as a lateral load that is sometimes generated on the wheel, is applied, the second shaft part breaks and the bearing fitting part elastically deforms to absorb the lateral load, further increasing the inclination of the gear in the reducer. There is an advantage that it can be surely suppressed.

  Further, there is an advantage that the bearing fitting portion can be elastically deformed to absorb a lateral load, and gear noise in the reduction gear can be reduced.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a sectional view of an in-wheel motor for a vehicle according to the present invention.
The vehicle in-wheel motor 11 is disposed on a wheel 12 and includes a motor housing 13 connected to a suspension device (not shown), a stator 14 and a rotor 15 disposed in the motor housing 13. The main motor output shaft 16 attached to the rotor 15, a first bearing (rolling bearing) 17 that supports the main motor output shaft 16 on the motor housing 13, and a first gear (pinion) 21 included in the main motor output shaft 16. A reduction gear 22 meshing with the first gear (pinion) 21, a second bearing (rolling bearing) 23 supporting the reduction gear 22 on the motor housing 13, and a rotation connected to the reduction gear 22. A shaft portion (secondary motor output shaft) 24, a hub 25 fitted to the rotary shaft portion (secondary motor output shaft) 24, and a rotary shaft portion (secondary motor output shaft) together with the hub 25 4 and the third bearing (rolling bearing) 26 where a bearing that supports that the, is provided with a.

The wheel 12 includes a wheel 31 attached to the hub 25 and a tire 32.
The rotor 15 is cylindrical and has a disk part 34 at one end 33 of the cylinder, and the end of the main motor output shaft 16 is integrally fitted into the opening of the disk part 34 so that the main motor output shaft 16 is fitted. And is rotatably supported by the motor housing 13.

  The main motor output shaft 16 is hollow, and a first gear (pinion) 21 that transmits driving force to the speed reducer 22 is formed at one end, and a fourth bearing 35 is fitted in the center of the first gear (pinion) 21. The rotor 15 is joined to the center and the first bearing 17 is fitted to the other end to serve as a support for the speed reducer 22.

The speed reducer 22 is a planetary gear speed reducer.
In the speed reducer 22, three gears 36, which are gears, are engaged with the first gear (pinion) 21 of the main motor output shaft 16 at an equal pitch central angle, so that the first gear (pinion) 21 is radially outward. On the other hand, the internal gear 37 meshes with the three gears 36 and is fixed to the motor housing 13 to form a disk-like output portion 41 that rotates by the revolution of the three gears 36 and outputs power, and is A bearing 35 is rotatably supported on the main motor output shaft 16, and a second bearing 23 is rotatably supported on the motor housing 13.

The output portion 41 is formed with a bearing fitting boss portion 42 fitting the second bearing 23 in the center, and the rotating shaft portion (secondary motor output shaft) 24 is integrated with a through hole opened in the bearing fitting boss portion 42. Are fitted together.
The planetary gear speed reducer (reduction gear) 22 is an example, and the specific configuration is arbitrary.

The rotary shaft portion 24 is divided into a first shaft portion 46 and a second shaft portion 47, and the first shaft portion 46 and the second shaft portion 47 are connected concentrically and in the space of the rotation center of the rotor 15. It is connected.
Further, a first shaft portion 46 having one end integrally attached to the output portion 41 of the planetary gear speed reducer 22, a shaft coupling member 51 to which the other end of the first shaft portion 46 is coupled, and a shaft coupling member And a second shaft portion 47 having the other end connected to 51, and transmits power to the hub 25.

  The hub 25 is formed with a fitting hollow shaft portion 52 that is fitted to the rotating shaft portion (secondary motor output shaft) 24, and is formed with a mounting plate portion 53 that is continuous with the fitting hollow shaft portion 52. The third bearing 26 is fitted to the outer diameter portion of the shaft portion 52 and supported by the motor housing 13.

The motor housing 13 includes a housing main body 54 to which the stator 14 is fixed and housing the rotor 15, and a wheel side lid 55 and a vehicle body side lid 56 that respectively seal the opening of the housing main body 54.
The vehicle body side cover 56 has a gear mounting portion 57 formed on the peripheral wall portion so that the internal gear 37 can be mounted, and a concave portion formed so as to fit the second bearing 23 in the center of the side wall portion connected to the peripheral wall portion. Concentric with the wheel side lid 55.

The wheel-side lid 55 is integrally formed with a bearing fitting portion 61 into which the hub 25 and the third bearing (rolling bearing) 26 are fitted at the center.
The bearing fitting portion 61 is a portion formed in a length and thickness that bulges into a cylindrical shape and elastically deforms with a predetermined force applied from the hub 25.

The first shaft portion 46 is formed so that the power input end portion 63 is fitted to the bearing fitting boss portion 42 at one end, and the motor housing 13 is fitted by the second bearing 23 fitted to the bearing fitting boss portion 42. The first stop portion 64 is formed at the other end, and the first connection end portion 65 (see FIG. 2) is formed so as to fit the shaft connection member 51 so as to be connected to the first stop portion 64.
The length of the first shaft portion 46 is a length at which the other end is disposed at the inner center of the rotor 15.

The second shaft portion 47 has the hub 25 fitted to the entire outer diameter portion, and is supported by the motor housing 13 by the third bearing 26 fitted to the hub 25, and the mounting plate portion 53 of the hub 25 is provided at one end. The second stop portion 66 is formed at the other end, and the second connection end portion 67 (see FIG. 2) is formed so as to fit the shaft connection member 51 so as to be connected to the second stop portion 66.
The length of the second shaft portion 47 is a length at which the other end is disposed at the inner center of the rotor 15.

  FIGS. 2A and 2B are diagrams for explaining an example of a shaft coupling member used in an in-wheel motor, where FIG. 2A is a cross-sectional view and FIG. 2B is an exploded view. This will be described with reference to FIG.

The shaft connecting member 51 is configured to engage the inner tooth ring 71 with an arc tooth ring 72 so as to be swingable. The retaining ring 73 restricts movement of the inner tooth ring 71 in the longitudinal direction and transmits rotational power.
The arc tooth ring 72 is formed with a shaft hole 74 into which a shaft is fitted, a key groove 75, a key set screw portion 76, and a retaining ring groove 77.
Further, the shaft connecting member 51 is arranged such that the axis Cu of the shaft connecting member 51 is concentric with the axis Cr of the rotor 15.

“The second shaft portion 47 is connected so as to be bent” means that the second shaft portion 47 is connected so that it can be bent by an angle δ (see FIG. 3).
The shaft connecting member 51 is an example, and the shape of the shaft connecting member is arbitrary.

Next, the operation of the vehicle in-wheel motor of the present invention will be described.
The in-wheel motor 11 for vehicles shown in FIG. 1 drives the wheel 12 by transmitting a driving force to the wheel 12 by the rotating shaft portion 24.
When the vehicle turns to the left or right while traveling by the in-wheel motor 11, the lateral deformation (X-axis direction) of the tire 32 and the load (lateral load) in the vehicle width direction (X-axis direction) are applied to the wheels 12, for example, by an arrow. Since it occurs like a1, a lateral load is applied to the rotating shaft portion 24 via the radius portion (tire 32, wheel 31) of the wheel 12. The rotating shaft portion 24 begins to bend (bend) as indicated by an arrow a2 due to a lateral load.

FIG. 3 is a schematic diagram for explaining a mechanism corresponding to a lateral load from a tire of an in-wheel motor for a vehicle. This will be described with reference to FIG.
When the rotation shaft portion 24 begins to bend (bend) as indicated by an arrow a2 due to a lateral load, the second shaft portion 47 bends with respect to the first shaft portion 46 by an angle δ with the shaft coupling member 51 as a fulcrum. The bending of the shaft portion 46 can be suppressed. As a result, it is possible to suppress the inclination (the direction of the arrow a3 or the arrow a4) of the three gears (gears) 36 orthogonal to the first shaft portion 46.

  Further, in the vehicle in-wheel motor 11, the shaft coupling member 51 is disposed on the inner side in the radial direction of the rotor 15 (the direction of the arrow a <b> 5). There is an advantage that the size of the in-wheel motor 11 in the vehicle width direction (X-axis direction) can be maintained.

  Further, when the rotating shaft portion 24 begins to bend as indicated by an arrow a2 due to a lateral load, the bearing fitting portion 61 starts to be elastically deformed with a predetermined thickness and length almost simultaneously, so that the lateral load is absorbed. The inclination of the three gears (gears) orthogonal to the first shaft portion 46 can be more reliably suppressed.

  In addition, since the bearing fitting portion 61 is elastically deformed, there is an advantage that gear noise in the reduction gear can be reduced.

  In the embodiment, the in-wheel motor for a vehicle according to the present invention is adopted as the concentric rotating shaft portion from the speed reducer (first shaft portion) to the hub (second shaft portion). It is also possible to employ the second shaft portion that is eccentric by a predetermined distance.

  The in-wheel motor for a vehicle according to the present invention is suitable for a concentric rotating shaft portion from a reduction gear (first shaft portion) to a hub (second shaft portion).

It is sectional drawing of the in-wheel motor for vehicles of this invention. It is a figure explaining an example of the shaft connection member used for the in-wheel motor. It is a schematic diagram explaining the mechanism corresponding to the lateral load from the tire of the in-wheel motor for vehicles.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... In-wheel motor for vehicles, 12 ... Wheel, 14 ... Stator, 15 ... Rotor, 24 ... Rotating shaft part, 25 ... Hub, 26 ... Bearing, 36 ... Gear (gear), 46 ... First shaft part, 47 ... 2nd shaft part, 51 ... Shaft coupling member, 61 ... Bearing fitting part.

Claims (3)

A hub that rotatably supports the wheel; a motor housing that supports the hub via a bearing and that houses the stator and the rotor; a gear that transmits the rotation of the rotor; and the rotation of the gear. A vehicle in-wheel motor comprising: a rotating shaft portion that transmits to the hub;
The rotating shaft portion includes a first shaft portion whose one end is attached to the gear, a first shaft portion disposed in series with the first shaft portion, a center supported by the bearing, and a hub disposed on one end side. An in-wheel motor for a vehicle, comprising: a two-shaft portion; and a shaft coupling member that flexibly connects the second shaft portion to the first shaft portion.   The in-wheel motor for a vehicle according to claim 1, wherein the first shaft portion and the second shaft portion are attached so that the shaft coupling member is disposed radially inward of the rotor. .   The said motor housing is provided with the bearing fitting part which fits the said bearing and elastically deforms according to the load added to the said 2nd shaft part via the said hub. The in-wheel motor for vehicles according to claim 2.

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