JP5598085B2 - Variable speed transmission unit - Google Patents

Description

  The present invention relates to a transmission transmission unit useful for a drive unit for each wheel (commonly referred to as an in-wheel motor unit) used in an electric vehicle capable of traveling by driving wheels by individual electric motors.

As such a speed change transmission unit, there has conventionally been proposed, for example, one described in Patent Document 1 configured as an in-wheel motor unit.
This in-wheel motor unit makes it possible to use a high-speed small transmission motor by using a reduction gear. In this case, a planetary gear set-type speed reducer is used as the speed reducer, and thus has an input shaft and an output shaft that are concentrically opposed to each other. An electric motor is coupled to the input shaft on one side in the axial direction (inside the vehicle body) of the reduction gear, and a wheel is coupled to the output shaft on the other side in the axial direction (outside the vehicle body) (see Patent Document 1).

  In an electric vehicle having such an in-wheel motor unit for each drive wheel, when the electric motor is driven, the rotation is transmitted to the wheel under deceleration by the speed reducer, and the vehicle can run.

  By the way, when the input and output shafts of the reducer that are coaxially opposed to each other are rotatably supported, the coaxial butted ends of the input and output shafts can be rotated relative to each other in order to reduce the axial dimension. Set the bearing fitting part between the input and output shafts by inserting them together, and place the input shaft and the output shaft that are separated from the bearing fitting part between the input and output shafts in the axial direction in the case of the in-wheel motor unit. Thus, the input / output shaft is supported.

JP 2008-037355 A (FIGS. 1 and 7)

  However, in such a reduction gear input / output shaft support structure, the coaxial butted ends of the input shaft and output shaft are fitted to each other so that they can rotate relative to each other. Since the parts of the input shaft and the output shaft that are spaced apart from each other are respectively bearing on the unit case, the following problems occur.

That is, when a lateral force (load in the vehicle width direction) is input from the wheel contact surface to the wheel during turning, the output shaft tends to tilt with the unit case side bearing portion as a fulcrum.
The inclination (falling) of the output shaft due to the lateral force of the wheel is caused to tilt to the input shaft through the input / output shaft bearing fitting portion, and the input shaft is tilted in a corresponding direction around the unit case side bearing portion, An axis crossing angle is generated between the input shaft and the output shaft in the input / output shaft bearing fitting portion.

  By the way, the input shaft and the output shaft are drive-coupled by the following planetary gear set type reduction gear. Therefore, an excessive inclination of the input / output shaft deteriorates the meshing between the rotating elements of the speed reducer, leading to deterioration in durability between components and generation of noise.

  The present invention has been made in view of the above problems, and even when an excessive external input such as a wheel lateral force enters the output shaft, a speed change mechanism such as a speed reducer generated by a large inclination between the input and output shafts. It is an object of the present invention to provide a speed change transmission unit that can suppress problems caused by the deterioration of the meshing between the rotating elements and the relative rotation parts such as a transmission motor coming into contact with each other.

For this purpose, the speed change transmission unit of the present invention is constituted as follows.
First, the transmission transmission unit, which is the premise of the present invention, will be described. This is because the coaxial abutting end portions of the input shaft and the output shaft are inserted so as to be relatively rotatable with each other, and the input / output shaft bearing fitting portion is set. In addition, the input shaft and the output shaft that are spaced apart from the input / output shaft bearing fitting portion in the axial direction are respectively bearing on the unit case, and the input shaft and the output shaft are drive-coupled by a speed change mechanism.

The present invention, in such variable transmission unit, provided with a contact surface for restricting the inclination of the axis of the input shaft and the output shaft by abutting on at least one axis of the input shaft and the output shaft, than the slope of the regulated In the range of small inclination, a gap allowing the inclination of the input shaft and output shaft is formed between the one shaft and the contact surface, and the contact surface rotatably supports the wheel hub of the unit case. Provided in the shield part arranged between the hub bearing and the drive unit, and the shield part has an oil seal separating the drive unit and the hub bearing, and this oil seal is provided on the drive unit side with respect to the contact surface It is characterized by the point configured as follows.

According to the speed change transmission unit of the present invention, when the external input acting on the output shaft is small and the inclination of the output shaft is small within an allowable range, the input shaft and the output between the one shaft and the contact surface are caused by the gap. When the external input is excessive and the output shaft tilts greatly while allowing the shaft to tilt, the input shaft and output can be made by contacting the contact surface provided on at least one of the input shaft and the output shaft. Regulate the tilt of the shaft.

Therefore, according to the present invention, even when an excessive external input such as a wheel lateral force enters the output shaft, the meshing between the rotating elements of the speed change mechanism, which is caused by a large inclination between the input and output shafts, is deteriorated. In addition, it is possible to suppress problems caused by relative rotating parts such as a transmission motor coming into contact with each other. Therefore, it is possible not only to prevent malfunction of the transmission mechanism and the like, but also to suppress the interference of the relative rotating parts and improve the durability of the transmission unit. Also, the shield part has an oil seal that separates the drive unit and the hub bearing, and this oil seal is provided on the drive unit side with respect to the contact surface. Therefore, it is possible to separate the drive unit composed of the electric motor and the speed change mechanism from the outer bearing and prevent the oil and grease from entering each other.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal side view showing a speed change transmission unit configured as an in-wheel motor unit according to a first embodiment of the present invention. FIG. 2 is an enlarged detail cross-sectional view of a main part of the in-wheel motor unit in FIG. FIG. 7 is a longitudinal side view showing a speed change transmission unit configured as an in-wheel motor unit according to a second embodiment of the present invention. FIG. 4 is an enlarged detailed cross-sectional view of a main part of the in-wheel motor unit in FIG. 3. It is a vertical side view which shows the transmission transmission unit comprised as an in-wheel motor unit of 3rd Example which concerns on this invention. It is an enlarged front view which shows the metal bush with a contact surface used with the in-wheel motor unit shown in FIG. It is the figure which showed typically the mode of inclination of the input-output shaft etc. of the in-wheel motor unit of 1st Example-3rd Example at the time of the limit inclination of an output shaft.

Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.
<Configuration of the first embodiment>
1 and 2 show a transmission transmission unit according to a first embodiment of the present invention configured as an in-wheel motor unit, FIG. 1 is a longitudinal side view thereof, and FIG. 2 is an enlarged detail cross-sectional view of an essential part thereof. .
As shown in these drawings, the in-wheel motor unit of the present embodiment is provided for each of the front, rear, left and right wheels of an electric vehicle or the like, and each includes a unit case 3, an electric motor 4, a planetary gear set type reduction gear 5 (hereinafter referred to as a gearbox). , Simply referred to as “reducer”).

  The unit case 3 includes a case body 1 of the in-wheel motor unit, a rear cover 2 that is assembled with bolts at a plurality of locations on the rear side of the case body 1 (inside the vehicle body), and a plurality of unit cases 3 on the front side of the case body 1 (outside the vehicle body). The shield member 30 is assembled at a location with bolts. In the unit case 3, the electric motor 4 and the speed reducer 5 are incorporated and stored. The electric motor 4 and the speed reducer 5 correspond to the drive unit of the present invention, and the shield member corresponds to the shield part of the present invention.

  The electric motor 4 is rotatable with an annular stator 6 fitted and fixed to the annular inner peripheral surface of the case body 1 and a radial gap with respect to the inner peripheral surface of the annular stator 6 And an annular stator 6 and a rotor 7 concentrically arranged.

  The speed reducer 5 corresponds to the speed change mechanism in the present invention, and in the present embodiment, the input shaft 8 and the output shaft 9 that are coaxially butted and opposed to each other, and the front side of the input shaft 8 near the coaxial butted end portion 8a. A sun gear 11 integrally formed on the outer surface, a ring gear 12 fixed to the case body 1 in a state of being concentrically arranged on the outer side of the sun gear 11 in the radial direction and close to the output shaft 9 side in the axial direction, and a large diameter meshing with the sun gear 11 A plurality of (three in this embodiment) stepped planetary pinions (stepped pinions) 13 including a pinion portion 13a and a small-diameter pinion portion 13b formed integrally therewith and meshing with the ring gear 12, and these stepped planetary pinions 13 And a carrier 14 that rotatably supports the.

The input shaft 8 has a rear side portion extending from the sun gear 11 toward the rear cover 2, and an inner peripheral side portion of a flange 7 a that fixes and supports the rotor 7 at an intermediate portion thereof is bolted.
On the other hand, the output shaft 9 has its front side portion extending from the speed reducer 5 in the direction opposite to the input shaft 8 (front side) and protruding from the front side end of the case body 1, that is, the opening of the shield member 30. The wheel 15 is coupled at the protruding portion as described later.

  In the input shaft 8 and the output shaft 9, the coaxial butted end portion 8a of the input shaft 8 is inserted into a hole 9b formed in the coaxial butted end portion 9a on the rear side of the output shaft 9, and a needle roller bearing is provided between them. By interposing the allowable bearing 16, an input / output shaft bearing fitting portion that supports each other so as to be relatively rotatable is set. In the present embodiment, the bearing 16 performs the fitting at substantially the same axial position when the sun gear 11 and the large-diameter gear portion 13a mesh with each other during the above-described fitting.

  A bearing 17 and a double row that allow ball bearings are provided at positions of the input shaft 8 and the output shaft 9, respectively, separated from the bearing 16 forming the input / output shaft bearing fitting portion in the axial direction rear side and front side. A bearing 18 that allows an angular bearing is mounted on the unit case 3. The bearing 18 is between the inner periphery of the end lid 19 that closes the front end opening of the case body 1 and the outer periphery of the wheel hub 21 that is fitted to the protruding portion of the output shaft 9 that protrudes from the front end opening of the case body 1. Intervene.

  The ring gear 12 is fixedly installed in the front end opening of the case body 1 so as not to rotate but to come off. The stepped planetary pinions 13 are arranged as a set of three at equal intervals in the circumferential direction, and the stepped planetary pinions 13 are rotatably supported by a common carrier 14 while maintaining the circumferentially equal intervals. The pinion carrier 14 includes carrier plates 14a and 14b, and carrier pins 14c that connect the plate plates 14a and 14b and rotatably support the stepped planetary pinion 13.

  In this embodiment, the front-side carrier plate 14a is integrally formed with the output shaft 9 at the rear end near the input shaft 8 of the output shaft 9, and serves as an output rotating member of the speed reducer 5. Therefore, the carrier 14 and the stepped planetary pinion 13 project from the output shaft 9 to the input shaft 8 side and are bound to the output shaft 9.

Next, a structure for coupling the wheel 15 to the output shaft 9 will be described.
On the inner peripheral side of the rotor of the wheel hub 21 and the brake disc 22 that is concentrically attached thereto, holes that are separated by a predetermined distance along the circumferential direction are provided so as to penetrate these bolt holes and protrude in the axial direction. A plurality of wheel bolts 23 are planted on the wheel hub 21.

  When installing the wheel 15, the wheel bolt 23 is aligned with the bolt hole drilled in the wheel disc so that the wheel disc is in close contact with the side surface of the brake disc 22. In this state, the wheel nut is attached to the wheel bolt 23. By tightening and screwing 24, the wheel 15 is attached to the output shaft 9.

  An annular shield member 30 extending radially inward toward the input shaft 8 is provided between the outer peripheral end of the support portion 21a disposed outside the wheel hub 21 via the ball bearing 17 and the case body 1. Tighten together with bolts. The inner peripheral side of the shield member 30 is bent to fix the oil seal 31, and the tip thereof is brought into contact with the outer peripheral surface of the input shaft 8. As a result, the oil seal 31 separates the inside and outside of the unit case 3 from each other, and thus the drive unit composed of the electric motor 4 and the speed reducer 5 and the bearing 18 outside thereof. Can be suppressed.

  A cylindrical metal bush 32 is fixed to the inner peripheral side end of the shield member 30. The metal bush 32 is opposed to the outer peripheral surface of the input shaft 8 with a gap 33 in the radial direction. As will be described later, the size of the annular gap 33 is such that when an excessive input from the outside acts on the output shaft 9 and the output shaft 9 is largely inclined with the bearing 18 of the case body 1 as a fulcrum, the output shaft 9 Reduce the output shaft 9 and input shaft 8 so that the output shaft 9 and the input shaft 8 do not tilt more than that (limit tilt angle). The size is set within an allowable range in which there is no adverse effect.

In the present embodiment, the size of the gap 33 is, for example, about 0.25 mm as shown in FIG. In the case of the first embodiment, the contact surface is closest to the bearing 18 as a fulcrum when the output shaft 9 receives an external input, as compared with the second and third embodiments described later. The direction dimension is small, and it is necessary to set it small from the viewpoint of variations in processing and assembly. In FIGS. 1 and 2, the size of the gap 33 is exaggerated and enlarged for easy understanding.
The contact surface of the metal bush 23 is located on the wheel 15 side from the oil seal 31 as can be seen from the figure.

The in-wheel motor unit configured as described above operates as follows.
<Operation of the first embodiment>
When the stator 6 of the electric motor 4 is energized, the rotor 7 of the electric motor 4 is rotationally driven by the electromagnetic force from now on, and this rotational driving force is transmitted to the sun gear 11 of the speed reducer 5 via the input shaft 8.
As a result, the sun gear 11 rotates the stepped planetary pinion 13 via the large-diameter gear portion 13a. At this time, since the fixed ring gear 12 functions as a reaction force receiver, the stepped planetary pinion 13 has a small-diameter gear portion 13b. Performs a planetary motion that rolls along the ring gear 12.
The planetary motion of the stepped planetary pinion 13 is transmitted to the output shaft 9 via the carrier 14 and rotates the output shaft 9 at a reduced speed in the same direction as the input shaft 8.

Due to the above transmission operation, the speed reducer 5 reduces the rotation from the electric motor 4 to the input shaft 8 at a ratio determined by the number of teeth of the sun gear 11 and the number of teeth of the ring gear 12 and transmits it to the output shaft 9.
The rotation to the output shaft 9 is transmitted to the wheel 15 via the wheel hub 21 and the wheel bolt 23 coupled to the output shaft 9, so that the vehicle can run.
When braking the vehicle, the intended purpose can be achieved by friction-braking the wheel 15 by clamping the brake disc 22 with the brake pad 25 from both sides in the axial direction.

  If the lateral force on the wheel 15 is small and the inclination angle of the output shaft 9 (the angle formed by the output shaft 9 with respect to the line connecting the bearings 17 and 18) is small during normal straight running, etc., between the output shaft 9 and the input / output shaft The inclination angle of the input shaft 8 connected by the bearing fitting portion (the angle formed by the input shaft 8 with respect to the line connecting the bearings 17 and 18) is also small. Therefore, in this case, the wheel 15 can be smoothly rotated without any trouble in the rotation of the speed reducer, the electric motor 4, and the like.

  On the other hand, when the lateral force on the wheel 15 is large and the inclination angle of the output shaft 9 is large due to curve driving etc., the outer peripheral surface of the output shaft 9 is the contact surface on the inner peripheral side of the metal bush 32 provided on the shield member 30. As long as it does not hit, a gap 33 is secured between them. Therefore, in this range, the meshing of the gear of the speed reducer deteriorates beyond the allowable range, or other peripheral parts interfere with each other, thereby hindering the operation of the in-wheel motor unit or deteriorating its durability. Such a problem does not occur.

  Further, when the inclination angle of the output shaft 9 is further increased, the outer peripheral surface of the output shaft 9 abuts the contact surface on the inner peripheral side of the metal bush 32 provided on the shield member 30, and the gap 33 in the portion where these contact with each other is It becomes zero. As a result, the output shaft 9 cannot be inclined any further, and as a result, the inclination of the input shaft 8 connected to the output shaft 9 by the coaxial abutting end portions 8a and 9a is prevented from further increasing. Since the inclination of these input / output shafts 8 and 9 can be suppressed to the limit inclination angle as described above, even in this case, the meshing with the gear of the reduction gear deteriorates beyond the allowable range, or other peripheral parts interfere with each other. Thus, there is no problem that the operation of the in-wheel motor unit is hindered or its durability is deteriorated.

  FIG. 7 schematically shows the relationship between the input / output shafts 8, 9 and the like in the case of the above limit inclination angle. The upper half of FIG. 7 shows the relationship between the input / output lines L81 and L91 representing the input / output shafts 8 and 9 in the first embodiment, and the lower half of FIG. The components are drawn in a diagram.

  As shown in the figure, in the case of the limit inclination angle, the output shaft 9 indicated by the line L91 rises to the left in the figure and contacts the contact surface of the metal bush 32 of the shield member 30 (shown in the figure A). ) Further inclination angle is suppressed. At this time, the contact portion A has moved about 0.25 mm radially outward from the case where the inclination angle is zero. On the other hand, the input shaft 8 indicated by the line L81 connected by the bearing 16 at the input / output shaft bearing fitting portion rises to the right in the figure, and the maximum inclination angle is suppressed.

  Therefore, in the in-wheel motor unit of the first embodiment, the meshing of the gear of the reduction gear is deteriorated beyond the allowable range, or other peripheral parts interfere with each other, and the operation of the in-wheel motor unit is hindered. The durability is not deteriorated. As shown in the figure, the bearing 16, the center point G1 of the sun gear 11, the center point G2 of the small-diameter pinion 13a, etc. are 16 ', G1', G2 ', etc. as a result of the input / output shafts 8 and 9 being inclined. It moves slightly in the axial direction as shown by.

<Effects of the first embodiment>
As described above, the speed change transmission unit of the first embodiment can obtain the effects listed below.
(1) A contact surface that restricts the inclination of one of the shafts by contacting the output shaft 9 is formed by the inner peripheral surface of the metal bush 32 fixed to the inner peripheral surface of the shield member 30 of the unit case 3. In the range of tilt smaller than the tilt to be configured, the output shaft 9 is configured to form a clearance 33 that allows the tilt of the input shaft 8 and the output shaft 9 between the contact surface and the output shaft 9. Even when the I / O shafts 8 and 9 are tilted, the radial movement distance K1 of the contact surface from the time when the input / output shafts 8 and 9 are at the tilt angle to the limit tilt angle can be suppressed to the size of the gap 33, and the speed reducer It is possible to prevent the meshing of the gears from deteriorating beyond an allowable range, interfering with other peripheral components, and hindering the operation of the in-wheel motor unit or deteriorating its durability. Therefore, there is no need to worry about these concerns, and an additional effect that the degree of design freedom is increased accordingly. On the other hand, since it is configured to form a gap 33 that allows the input shaft 8 and the output shaft 9 to be tilted between the output shaft 9 and the contact surface, the normal running state (the state in which excessive external input is not acting) ), The shaft does not hit the surface for the time being, so that the shaft is allowed to fall down due to the generated vibration or the like. Therefore, it is possible to prevent the rotation of the shaft from interfering with the normal traveling state and the generation of abnormal noise.

  (2) Since the contact surface is provided outside the drive unit consisting of the speed reducer and the electric motor 4, it is possible to suppress contamination that occurs when the contact surface hits the outer peripheral surface of the output shaft 9 from entering the drive unit. Can do.

  (3) Since the oil seal 31 attached to the shield member 30 is provided on the drive unit side with respect to the contact surface, contamination from the contact surface or the outside to the inside of the drive unit can be reliably prevented.

  (4) Since the contact surface is formed by the metal bush 32, the maximum inclination angle can be regulated within the limit inclination angle while allowing the output shaft 9 to rotate.

  For this reason, in the first embodiment, the gears 13a of the stepped planetary pinion 13 and the meshing part of the sun gear 11 on the input shaft 8 hardly cause any gear contact, and the speed reducer 5 It is possible to eliminate the concern that the operation will be hindered or that the durability thereof will be reduced, and it is possible to surely eliminate the concern that the relative rotating parts come into contact with each other.

<Configuration of the second embodiment>
Next, a second embodiment according to the present invention will be described.
3 and 4 show a transmission gear transmission unit according to a second embodiment of the present invention configured as an in-wheel motor unit as in the first embodiment, FIG. 3 is a longitudinal side view thereof, and FIG. 4 is a main portion thereof. It is an enlarged detailed sectional view.
In these drawings, parts that function in the same manner as in FIGS. 1 and 2 are denoted by the same reference numerals. Here, only parts different from the first embodiment shown in FIGS. Avoid duplicating explanations of important components.

  This embodiment differs from the first embodiment in that a contact surface is provided on the output shaft side instead of the first embodiment in which a metal bush is provided on the inner peripheral surface of the shield member with a contact surface.

  For this reason, in this embodiment, as in the first embodiment, the input shaft 8 and the output shaft 9 are connected to the coaxial butted end portion 8a of the input shaft 8 and the coaxial butted end portion 9a on the rear side of the output shaft 9. By inserting a bearing 16 that allows a needle roller bearing between them, an input / output shaft bearing fitting portion that supports each other so as to be relatively rotatable is set.

  An annular metal bush 34 is fixed to a position on the front side of the bearing 16 on the inner peripheral surface of the hole 9b formed in the coaxial abutting end portion 9a of the output shaft 9. The inner peripheral surface of the metal bush 34 forms a contact surface, and an annular gap 33 is formed in the radial direction between the coaxial abutting end portion 8a of the input shaft 8 and the front side portion from the bearing 16. In this embodiment, the limit inclination angle of the output shaft 9 is set larger than that in the first embodiment. Further, since the contact surface is closer to the rear side than the bearing 18, the gap 33 in the second embodiment is set to, for example, about 0.7 mm as shown in FIG.

<Operation of Second Embodiment>
Also in the second embodiment shown in FIGS. 3 and 4 described above, the rotational driving force of the electric motor 4 (rotor 7) passes through the input shaft 8, the sun gear 11 of the speed reducer 5, the stepped planetary pinion 13, and the output shaft 9 sequentially. Can be transmitted to the wheels 15 to drive the vehicle.

  When the lateral force to the wheel 15 is small and the inclination angle of the output shaft 9 is small due to normal straight traveling or the like, the inclination angle of the input shaft 8 connected by the output shaft 9 and the input / output shaft bearing fitting portion is also small. Therefore, in this case, the wheel 15 can be smoothly rotated without any trouble in the rotation of the speed reducer, the electric motor 4, and the like.

  On the other hand, when the lateral force on the wheel 15 is large and the inclination angle of the output shaft 9 becomes large due to curve driving etc., the outer peripheral surface of the coaxial abutting end 8a of the input shaft 8 on the contact surface of the metal bush 34 of the output shaft 9 In the range where does not hit the contact surface, a gap 33 is secured between them. Therefore, in this range, the meshing of the gear of the speed reducer deteriorates beyond the allowable range, or other peripheral parts interfere with each other, thereby hindering the operation of the in-wheel motor unit or deteriorating its durability. Such a problem does not occur.

  When the inclination angle of the output shaft 9 is further increased, the outer peripheral surface of the coaxial butted end portion 8a of the input shaft 8 abuts on the inner peripheral side contact surface of the metal bush 34 provided in the hole 9b of the output shaft 9. The gap 33 at the part where they abut is zero. As a result, the output shaft 9 cannot be inclined any further, and as a result, the inclination of the input shaft 8 connected to the output shaft 9 by the coaxial abutting end portions 8a and 9a is prevented from further increasing. Since the inclination of these input / output shafts 8 and 9 can be suppressed to the limit inclination angle as described above, even in this case, the meshing with the gear of the reduction gear deteriorates beyond the allowable range, or other peripheral parts interfere with each other. Thus, there is no problem that the operation of the in-wheel motor unit is hindered or its durability is deteriorated.

  As schematically shown in FIG. 7 which shows the relationship between the input / output shafts 8 and 9 when the tilt angle is at the above limit tilt angle, in the case of the limit tilt angle, the output shaft 9 indicated by the line L92 rises to the left in the figure. Thus, it is suppressed that the coaxial butted end portion 8a of the input shaft 8 abuts against the contact surface of the metal bush 34 of the output shaft 9 (shown in FIG. 5B) and the inclination angle is further increased. At this time, the contact portion B has moved about 0.7 mm radially outward from the case where the inclination angle is zero. On the other hand, the input shaft 8 indicated by the line L81 connected by the bearing 16 at the input / output shaft bearing fitting portion rises to the right in the figure, and the maximum inclination angle is suppressed. The bearing 16 comes to a position indicated by 16 ".

  Therefore, in the in-wheel motor unit according to the second embodiment, the meshing of the speed reducer with the gear deteriorates beyond the allowable range, or other peripheral parts interfere with each other, thereby hindering the operation of the in-wheel motor unit. The durability is not deteriorated.

<Effect of the second embodiment>
As can be seen from the above, the in-wheel motor unit of the second embodiment has the following effects in addition to the effect (1) of the first embodiment.
(5) The contact surface of the metal bush 34 is provided on the front side of the bearing 16 between the coaxial butted end 8a of the input shaft 8 inserted into the hole 9b formed in the coaxial butted end 9a of the output shaft 9. Therefore, it is possible to suppress the contamination generated on the contact surface from entering the drive unit.

(6) Further, since the metal bush 34 is disposed between the coaxial abutting end portions 8a and 9a, the structure is compact and the degree of freedom in designing the in-wheel motor unit is increased.

<Third embodiment>
Next, a third embodiment according to the present invention will be described below.
FIG. 5 is a longitudinal side view showing a transmission transmission unit according to a third embodiment of the present invention configured as an in-wheel motor unit as in the first embodiment, and FIG. 6 is used in the transmission transmission unit according to the third embodiment. It is an enlarged front view of a metal bush with a contact surface.
In these drawings, parts that function in the same manner as in FIGS. 1 and 2 are denoted by the same reference numerals. Here, only parts different from the first embodiment shown in FIGS. Avoid duplicating explanations of important components.

  In the third embodiment, the planetary gear mechanism constituting the speed reducer is configured in the same manner as in the first embodiment. In other words, the speed reducer has a sun gear 11, a ring gear 12, and a pinion carrier 14 that rotatably supports a stepped piston 13. The pinion carrier 14 includes a front carrier plate 14a integrally formed by extending outward from the outer periphery of the coaxial abutting end 9a of the output shaft 9 on the front side, a rear carrier plate 14b provided on the rear side, and a space between them. And a pinion shaft 14c that rotatably supports the stepped pinion 13 is provided. The pinion shaft 14c is equally divided into three places around the circumference of the input and output shafts 8 and 9, and has an axial oil hole and a radial oil hole connected thereto, and is stepped. Oil is supplied to the needle bearing that supports the pinion. The axial oil hole is connected to a radial oil hole formed in the rear carrier plate 14b so as to receive the oil blown from the blowing oil hole of the input shaft 8 at the inner peripheral side opening. It is.

  An annular metal bush 35 is attached to the inner peripheral side of the rear carrier plate 14b by welding or the like. The inner peripheral surface of the metal bush 35 forms a contact surface, and a gap 33 is formed in the radial direction between the inner peripheral surface and the portion of the input shaft 8 facing the inner peripheral surface. In the third embodiment, the gap 33 is set to 0.6 mm as shown in FIG. 7 in order to keep the same limit inclination angle as in the second embodiment.

  As shown in FIG. 6, the metal bush 35 is formed in an annular shape, and an oil hole 35a is formed in accordance with the position of the pinion shaft 14c. The oil hole 35a has an inner diameter that is larger than the diameter of the oil hole of the rear carrier plate 14b to make it easier to receive oil, and the diameter of the oil hole of the rear side carrier plate 14b increases toward the outside in the radial direction. Reduce the diameter. The metal bush 35 may be formed with an oil receiving groove along the circumference on the inner circumferential surface. In order to facilitate oil supply to the oil hole of the rear carrier plate 14b on the outer circumferential side, You may make it form the oil groove of a direction.

<Operation of the third embodiment>
Even in the in-wheel motor unit of the third embodiment, as in the first and second embodiments, when the inclination of the output shaft 9 is small, it is between the input shaft 8 and the metal bush 35 of the rear carrier plate 14b. Therefore, the gap 33 is secured and can be operated smoothly.
On the other hand, when the inclination of the output shaft 9 is increased, the input shaft 8 connected via the bearings 16 of the coaxial abutting end portions 8a and 9a is inclined, and at the limit inclination angle, the outer periphery of the input shaft 8 is the rear carrier plate 14b. It hits the inner peripheral surface of the metal bush 35, that is, the contact surface. Thereby, further inclination of the input shaft 8 is suppressed, and further inclination of the output shaft 9 connected to the input shaft via the bearing 16 is also suppressed. As a result, problems such as poor meshing at the reduction gear and interference with other parts can be prevented.

  This state is shown in FIG. 7, and the input shaft 8 indicated by the line L83 and the output shaft 9 indicated by the line L93 are the same as the lines L82 and L92 of the second embodiment. The radial movement distance K3 of the contact surface from when the input / output shafts 8 and 9 are at a tilt angle of zero to the limit tilt angle can be suppressed to the size of the gap 33. Further, the limit inclination angle is determined by the contact between the contact surface of the metal bush 35 of the rear carrier plate 14b and the outer peripheral surface of the input shaft 8 at the position where the line L93 of the output shaft 9 is extended to the rear side. ing. Accordingly, in this case, the contact surface comes into contact with the line L93 rising left and the line L83 rising right in FIG. 7 at a position far away in the radial direction. In contrast, in the first embodiment, the contact surface is closest to the bearing 18, and in the second embodiment, the contact surface is farther from the bearing 18 than the contact surface of the first embodiment, but the contact surface of the third embodiment. It is in a position much closer to the bearing 18. From this, the third embodiment has the largest radial distance between the contact surface and the metal bushes 32, 34, 35 on the contact side with respect to the same inclination of the output shaft 9. This means that the sensitivity to the inclination of the output shaft 9 is the highest in the third embodiment.

<Effect of the third embodiment>
As can be seen from the above, in the in-wheel motor unit of the third embodiment, the following effects can be obtained in addition to the effects (1) and (4) of the first embodiment.
(7) The outer periphery of the input shaft 8 is configured by the inner peripheral surface of the metal bush 35 provided on the inner peripheral surface of the rear carrier plate 14b and connected to the contact surface via the output shaft 9 and the bearing 16 Since the surface is applied, the sensitivity to the inclination of the output shaft 9 is increased. Therefore, there is an advantage that the design is easy.

Although the present invention has been described based on the above-described embodiments, the present invention is not limited to these embodiments, and includes various modifications as described below.
The unit case 3 is composed of the case body 1, the rear cover 2, and the shield member 30 in each of the above embodiments. However, the unit case 3 is not limited to this, and for example, the shield member 30 is integrally formed with the case body 1. It goes without saying that it is also good.
The metal bushes 32, 34, and 35 are located on the other side of the shafts 8 and 9 (such as the case body 1 and the pinion carrier 14) at positions away from the outer peripheral surfaces of the shafts 8 and 9, but conversely It may be provided on the shafts 8 and 9 side so that the outer peripheral surface is brought into contact with the other side.
Furthermore, in each of the embodiments described above, the contact surface is formed on the metal bush 32, 34, 35, but the inner peripheral surface on the inner ring side and the outer peripheral surface of the outer ring are used as the contact surface using other types of bearings. It is also possible to use other than bearings.
In each of the above-described embodiments, the speed change transmission unit is configured as an in-wheel motor unit of an electric vehicle. However, the present invention is not limited to this, and needless to say, the transmission transmission unit can be applied to any industrial transmission unit.

  In each of the above-described embodiments, the case where the planetary gear set type reduction gear is used as the speed change mechanism in the speed change transmission unit has been described. However, the speed change mechanism in the speed change transmission unit is not limited to this, and any type of speed change mechanism can be used. A mechanism (including a speed increasing mechanism) can be used, and in this case as well, it is a matter of course that the same effect can be obtained by applying the idea of the present invention.

1 Case body
2 Rear cover
3 Unit case
4 Electric motor
5 Planetary gear set reducer (transmission mechanism)
6 Stator
7 Rotor
8 Input shaft
8a Coaxial butt end
9 Output shaft
9a Coaxial butt end 9b Hole
11 Sungear
12 Ring gear
13 Stepped planetary pinion (Stepped pinion)
13a Large diameter gear
13b Small diameter gear
14 Pinion carrier
14a, 14b Carrier plate
14c carrier pin
15 wheels
16 Roller bearing (I / O shaft bearing fitting part)
17 Ball bearing
18 Double row angular contact bearings
19 End cover
21 Wheel hub
22 Brake disc
23 Wheel bolt
24 Wheel nut
30 Shield material
31 Oil seal
32 Metal bush
33 Clearance
34 Metal bush
35 Metal bush

Claims (1)

The input / output shaft bearing fitting portion is set by inserting the coaxial butted ends of the input shaft and the output shaft so as to be relatively rotatable with each other, and the input is separated from the input / output shaft bearing fitting portion in the axial direction. Bearing the shaft and output shaft in the unit case,
In a transmission transmission unit in which the input shaft and the output shaft are drive-coupled by a transmission mechanism,
A unit case that houses a drive unit that includes the speed change mechanism and an electric motor that drives the speed change mechanism;
Setting a contact surface for regulating the inclination of said input shaft and said output shaft by abutting on at least one axis of said input shaft and said output shaft,
In an inclination range smaller than the regulating inclination, a gap allowing the inclination of the input shaft and the output shaft is formed between the one shaft and the contact surface ,
The abutting surface is provided in a shield portion disposed between the drive bearing unit and a hub bearing that rotatably supports a wheel hub of a wheel of the unit case,
The shield part has an oil seal that separates the drive unit and the hub bearing;
The speed change transmission unit , wherein the oil seal is provided on the drive unit side with respect to the contact surface .

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