JP6003557B2 - Deceleration mechanism and motor rotational force transmission device having the same - Google Patents

Description

  The present invention relates to a speed reduction mechanism suitable for use in, for example, an electric vehicle having an electric motor as a drive source, and a motor rotational force transmission device including the speed reduction mechanism.

  A conventional motor rotational force transmission device includes an electric motor that generates a motor rotational force, and a deceleration transmission mechanism that decelerates the motor rotational force of the electric motor and transmits a driving force to a differential mechanism. (See, for example, Patent Document 1).

  The deceleration transmission mechanism of this type of motor torque transmission device is composed of a trochoidal curve such as epitrochoid on the outer periphery that is an example of an external gear mechanism that revolves by the rotation of a motor shaft with an eccentric portion of an electric motor. A pair of revolution members made of a disk-shaped curved plate having a plurality of corrugations, a plurality of outer pins that are examples of an internal gear mechanism that imparts a rotation force to these revolution members, and a revolution member inside these outer pins A plurality of inner pins for outputting the rotation force of the motor as a rotational force to the differential mechanism.

  The pair of revolution members have a center hole whose central axis is an axis different from the axis of the eccentric part of the motor shaft with the eccentric part, and a plurality of pin insertion holes arranged in parallel at equal intervals around the central axis of the central hole. The motor shaft with the eccentric portion is rotatably supported by the eccentric portion via a bearing (cam-side bearing).

  The plurality of outer pins are arranged at equal intervals around the axis of the motor shaft with the eccentric portion, and are attached to the housing of the speed reduction transmission mechanism.

  The plurality of inner pins are disposed through the plurality of pin insertion holes in the revolution member, and are attached to the differential case. A bearing (pin side bearing) for reducing contact resistance between the inner peripheral surfaces of the plurality of pin insertion holes in the pair of revolution members is attached to the plurality of inner pins.

JP 2007-218407 A

  In the motor rotational force transmission device shown in Patent Document 1, it is not only necessary to prepare a plurality of outer pins, but the outer peripheral portion of the revolving member needs to have a complicated shape, which is uneconomical.

  Therefore, the revolution member is an external gear that is a gear that is an example of an external gear mechanism, and the rotation force applying member that is used to apply a rotation force to the revolution member is a gear that is an example of an internal gear mechanism. It is conceivable to eliminate the above-described inefficiency by setting the number of teeth of the internal gear to be larger than the number of teeth of the external gear.

  However, a reduction transmission mechanism including a disc-shaped curved plate having a plurality of waveforms formed of a trochoid system curve such as epitrochoid and a plurality of external pins on the outer peripheral portion shown in Patent Document 1, and an external gear as a gear When a reduction transmission mechanism using an external gear mechanism such as a reduction transmission mechanism using an internal gear that is a gear and an internal gear mechanism is used in a motor torque transmission device of an automobile, the revolution speed of the external gear mechanism that is a revolution member Is relatively high, a load due to centrifugal force is applied from the revolving member to the cam-side bearing during output. As a result, it is necessary to use a highly durable bearing as the cam-side bearing, which increases costs. Further, when a load due to centrifugal force is applied to the cam-side bearing, there is a problem that the life of the cam-side bearing is reduced.

  Accordingly, an object of the present invention is to provide a speed reduction mechanism capable of extending the life of a bearing and a motor rotational force transmission device including the speed reduction mechanism.

  In order to achieve the above object, the present invention provides a speed reduction mechanism (1) to (8) and a motor torque transmission device including the speed reduction mechanism.

(1) A rotary shaft that rotates around the first axis and has an eccentric portion having a second axis that is eccentric from the first axis as a central axis, and an outer periphery of the rotary shaft; And a plurality of through holes arranged in parallel at equal intervals around the third axis, and between the inner peripheral surface of the central hole and the outer peripheral surface of the eccentric part. An input member comprising an external gear mechanism having a pitch circle having a center axis as the third axis with a bearing interposed therebetween, and the external gear mechanism being disposed by being fitted to the input member in the radial direction thereof. A cylindrical housing having a rotation force application member comprising an internal gear mechanism having a pitch circle having a fourth axis as a central axis and meshing with the input member with a number of teeth larger than the number of teeth The rotation force applying member of the An output member that receives and outputs the rotation force applied to the member, and has the outer ring and the inner ring, the outer ring in the center hole, and the inner ring in the center hole. When the eccentric portion is fitted with a gap in the radial direction of the rotary shaft, the dimension between the second axis and the third axis is orthogonal to the second axis and the fourth axis. In the state where the input member moves on the line to be in contact with the housing, the difference in diameter between the outer diameter of the bearing and the inner diameter of the center hole, and between the inner diameter of the bearing and the outer diameter of the eccentric portion The speed reduction mechanism is set to a dimension that is less than half of the dimension obtained by adding the diameter difference of the bearing and the operating clearance of the radial internal clearance of the bearing.

(2) In the speed reduction mechanism described in (1) above, the input member has an annular first convex portion having the third axis as a central axis, and the housing has the first convex And an annular second convex portion having the fourth axis as a central axis.

(3) In the speed reduction mechanism according to (2), the input member has a fitting surface of the first convex portion formed on an outer peripheral surface, and the housing has a fitting surface of the second convex portion. Is formed on the inner peripheral surface.

(4) In the speed reduction mechanism according to (2), the input member has a fitting surface of the first convex portion formed on an inner peripheral surface, and the housing is fitted with the second convex portion. The surface is formed by the outer peripheral surface.

(5) In the speed reduction mechanism according to (3) or (4), the input member protrudes in the third axial direction to form the first convex portion, and the housing includes the fourth protrusion. The second protrusion is formed so as to protrude in the axial direction.

(6) In the reduction mechanism according to (3), the input member protrudes in a direction orthogonal to the third axis to form the first convex portion, and the housing has the fourth axis. The second convex portion is formed so as to protrude in a direction orthogonal to the first convex portion.

(7) In a motor rotational force transmission device comprising: an electric motor that generates a motor rotational force; and a deceleration transmission mechanism that decelerates the motor rotational force of the electric motor and transmits a driving force to a driving force transmission target. The reduction transmission mechanism is a motor rotational force transmission device that is the reduction mechanism according to any one of (1) to (6) above.

(8) In the motor rotational force transmission device according to (7), the deceleration transmission mechanism transmits the driving force to a differential mechanism serving as the driving force transmission target.

  According to the present invention, the cost can be reduced and the life of the bearing can be extended.

The top view shown in order to demonstrate the outline of the vehicle carrying the motor rotational force transmission apparatus which concerns on the 1st Embodiment of this invention. Sectional drawing shown in order to demonstrate the motor rotational force transmission apparatus which concerns on the 1st Embodiment of this invention. FIG. 3 is a cross-sectional view schematically showing the deceleration transmission mechanism of the motor torque transmission device according to the first embodiment of the present invention. Sectional drawing which shows typically the principal part of the deceleration transmission mechanism in the motor rotational force transmission apparatus which concerns on the 1st Embodiment of this invention. (A) And (b) is the front view and sectional drawing which show the contact state of the input member with respect to the autorotation force provision member of the deceleration transmission mechanism in the motor rotational force transmission apparatus which concerns on the 1st Embodiment of this invention. (A) is a front view, and (b) is a cross-sectional view. Sectional drawing which simplifies and shows the support state of the input member of the deceleration mechanism in the motor rotational force transmission apparatus which concerns on the 1st Embodiment of this invention. Sectional drawing which models the principal part of the deceleration mechanism in the motor rotational force transmission apparatus which concerns on the 1st Embodiment of this invention, and shows the modification (1). Sectional drawing which models the principal part of the deceleration mechanism in the motor rotational force transmission apparatus which concerns on the 1st Embodiment of this invention, and shows the modification (2). Sectional drawing which simplifies and shows the support state of the input member of the deceleration mechanism in the motor rotational force transmission apparatus which concerns on the 2nd Embodiment of this invention. Sectional drawing which simplifies and shows the support state of the input member of the deceleration mechanism in the motor rotational force transmission apparatus which concerns on the 3rd Embodiment of this invention. Sectional drawing which simplifies and shows the support state of the input member of the deceleration mechanism in the motor rotational force transmission apparatus which concerns on the 4th Embodiment of this invention. Sectional drawing which simplifies the support state of the input member of the deceleration mechanism in the motor rotational force transmission apparatus which concerns on the 1st Embodiment of this invention, and shows the modification (3). Sectional drawing which simplifies the support state of the input member of the deceleration mechanism in the motor rotational force transmission apparatus which concerns on the 2nd Embodiment of this invention, and shows the modification (4). Sectional drawing which simplifies the support state of the input member of the deceleration mechanism in the motor rotational force transmission apparatus which concerns on the 3rd Embodiment of this invention, and shows the modification (5). Sectional drawing which simplifies the support state of the input member of the deceleration mechanism in the motor rotational force transmission apparatus which concerns on the 4th Embodiment of this invention, and shows the modification (6).

[First embodiment]
Hereinafter, a motor torque transmission device according to a first embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 schematically shows a four-wheel drive vehicle. As shown in FIG. 1, a four-wheel drive vehicle 101 uses a front-wheel-side power system that uses a drive source as an engine, and a rear-wheel-side power system that uses a drive source as an electric motor. , An engine 102, a transaxle 103, a pair of front wheels 104, and a pair of rear wheels 105.

  The motor rotational force transmission device 1 is disposed in a power system on the rear wheel side of the four-wheel drive vehicle 101 and is supported by a vehicle body (not shown) of the four-wheel drive vehicle 101.

  The motor rotational force transmission device 1 transmits a driving force based on the motor rotational force of the electric motor 4 (shown in FIG. 2) to the pair of rear wheels 105. As a result, the motor rotational force of the electric motor 4 is output to the rear axle shaft 106 via the deceleration transmission mechanism 5 and the rear differential 3 (both shown in FIG. 2), and the pair of rear wheels 105 are driven. Details of the motor rotational force transmission device 1 and the like will be described later.

  The engine 102 is disposed in the power system on the front wheel side of the four-wheel drive vehicle 101. As a result, the driving force of the engine 102 is output to the front axle shaft 107 via the transaxle 103, and the pair of front wheels 104 are driven.

(Whole structure of the motor rotational force transmission device 1)
FIG. 2 shows the entire motor torque transmission device. As shown in FIG. 2, the motor rotational force transmission device 1 includes a housing 2 having a center axis that is an axis (rotation axis O as a first axis) of a rear axle shaft 106 (shown in FIG. 1), and a pair of rear wheels. 105 (shown in FIG. 1), a rear differential 3 as a driving force transmission target that distributes the driving force, an electric motor 4 that generates a motor rotational force for operating the rear differential 3, and a motor rotational force of the electric motor 4 And a deceleration transmission mechanism 5 that transmits the driving force to the rear differential 3 by decelerating the motor.

(Configuration of housing 2)
The housing 2 includes a rotation force applying member 52 to be described later, a first housing element 20 that houses the rear differential 3, a second housing element 21 that houses the electric motor 4, and a one-side opening of the second housing element 21. And a third housing element 22 that closes a portion (an opening on the side opposite to the opening on the first housing element 20 side).

  The first housing element 20 is disposed on one side of the housing 2 (left side in FIG. 2), and is entirely formed of a stepped bottomed cylindrical member that opens to the second housing element 21 side. A shaft insertion hole 20 a through which the rear axle shaft 106 (shown in FIG. 1) is inserted is provided at the bottom of the first housing element 20. On the opening end surface of the first housing element 20, an annular convex portion (second convexity) that protrudes toward the second housing element 21 along the direction of the fourth axis (rotation axis O in the present embodiment). Part) 23 is provided integrally. An inner peripheral surface (a fitting surface for one input member 50) 23a of the convex portion 23 has an inner diameter larger than the maximum inner diameter of the first housing element 20, and is formed by a circumferential surface having the rotation axis O as a central axis. Has been. The outer peripheral surface 23 b of the convex portion 23 has an outer diameter smaller than the maximum outer diameter of the first housing element 20 and is formed by a circumferential surface having the rotation axis O as the central axis. The inner peripheral surface of the first housing element 20 is disposed between the outer peripheral surface of the rear axle shaft 106 and a seal member 24 that seals the shaft insertion hole 20a.

  The second housing element 21 is disposed at an intermediate portion in the axial direction of the housing 2, and is entirely formed by a bottomless cylindrical member that opens in both directions of the fourth axis (rotation axis O). A stepped inner flange 21 a interposed between the electric motor 4 and the speed reduction transmission mechanism 5 is integrally provided at one side opening of the second housing element 21 (opening on the first housing element 20 side). ing. An annular member 25 for attaching a race is attached to the inner peripheral surface of the inner flange 21a. An annular projecting portion (second projection) projecting toward the first housing element 20 along the rotation axis O direction is formed on one side opening end surface of the second housing element 21 (opening end surface on the first housing element 20 side). (Convex portion) 27 is integrally provided. An inner peripheral surface (a fitting surface with respect to the other input member 51) 27a of the convex portion 27 is a circumferential surface having an inner diameter substantially the same as the maximum inner diameter of the second housing element 21 and having the rotation axis O as a central axis. Is formed. The outer peripheral surface 27b of the convex portion 27 is a circumferential surface having an outer diameter that is smaller than the outer diameter of the second housing element 21 and substantially the same as the outer diameter of the convex portion 23 and that has the rotation axis O as the central axis. Is formed.

  The third housing element 22 is disposed on the other side of the housing 2 (the right side in FIG. 2), and is entirely formed by a stepped bottomed cylindrical member that opens to the second housing element 21 side. A shaft insertion hole 22 a through which the rear axle shaft 106 is inserted is provided at the bottom of the third housing element 22. A cylindrical portion 22b for attaching a stator that protrudes toward the electric motor 4 is integrally provided on the inner opening periphery of the shaft insertion hole 22a. The inner peripheral surface of the third housing element 22 is disposed between the outer peripheral surface of the rear axle shaft 106 and a seal member 24 that seals the shaft insertion hole 22a.

(Configuration of rear differential 3)
The rear differential 3 includes a bevel gear type differential mechanism having a differential case 30, a pinion gear shaft 31, a pair of pinion gears 32, and a pair of side gears 33, and is disposed on one side of the motor rotational force transmission device 1.

  As a result, the rotational force of the differential case 30 is distributed from the pinion gear shaft 31 to the side gear 33 via the pinion gear 32, and further from the side gear 33 to the left and right rear wheels 105 (shown in FIG. 1) via the rear axle shaft 106 (shown in FIG. 1). ).

  On the other hand, when a driving resistance difference occurs between the left and right rear wheels 105, the rotational force of the differential case 30 is differentially distributed to the left and right rear wheels 105 by the rotation of the pinion gear 32.

  The differential case 30 is disposed on an axis different from the rotation axis O, and rotates via the ball bearing 34 on the first housing element 20 and via the ball bearing 35 on the motor shaft (rotation shaft) 42 of the electric motor 4. Supported as possible. The differential case 30 rotates by receiving a driving force based on the motor rotational force of the electric motor 4 from the deceleration transmission mechanism 5.

  The differential case 30 includes a housing space 30a that houses the differential mechanism (pinion gear shaft 31, pinion gear 32, and side gear 33), and a pair of shaft insertion holes 30b that communicate with the housing space 30a and through which the left and right rear axle shafts 106 are respectively inserted. Is provided.

  The differential case 30 is integrally provided with an annular flange 30 c that faces the speed reduction transmission mechanism 5. The flange 30c is provided with a plurality (six in this embodiment) of pin attachment holes 300c arranged in parallel at equal intervals around the axis of the differential case 30.

  The pinion gear shaft 31 is disposed on the axis L perpendicular to the axis in the accommodation space 30 a of the differential case 30, and the rotation around the axis L and the movement in the direction of the axis L are restricted by the pin 36.

  The pair of pinion gears 32 is rotatably supported by the pinion gear shaft 31 and is accommodated in the accommodating space 30 a of the differential case 30.

  The pair of side gears 33 have shaft connecting holes 33a for connecting the left and right rear axle shafts 106 (shown in FIG. 1) by spline fitting, and are accommodated in the accommodating space 30a of the differential case 30. The pair of side gears 33 mesh with the pair of pinion gears 32 with their gear shafts orthogonal to the gear shafts of the pair of pinion gears 32.

(Configuration of electric motor 4)
The electric motor 4 includes a stator 40, a rotor 41, and a motor shaft 42. The electric motor 4 is connected to the rear differential 3 via a reduction transmission mechanism 5 on the rotation axis O, and the stator 40 is an ECU (Electronic Control Unit: not shown). )It is connected to the. In the electric motor 4, the stator 40 receives a control signal from the ECU, generates a motor rotational force for operating the rear differential 3, and rotates the rotor 41 together with the motor shaft 42.

  The stator 40 is disposed on the outer peripheral side of the electric motor 4 and is attached to the inner flange 21 a of the second housing element 21 by mounting bolts 43.

  The rotor 41 is disposed on the inner peripheral side of the electric motor 4 and is attached to the outer peripheral surface of the motor shaft 42.

  The motor shaft 42 is disposed on the rotation axis O, and has one end on the inner peripheral surface of the annular member 25 via a ball bearing 44 and a sleeve 45 and the other end on the third housing element 22. These are respectively rotatably supported by ball bearings 46 and formed entirely by a cylindrical shaft member through which a rear axle shaft 106 (shown in FIG. 1) is inserted.

The one side end portion of the motor shaft 42, flat circular eccentric portion 42a to the rotational axis (first axis) axis eccentric with a eccentricity [delta] ₁ from O (second axis) center axis line O ₁ and eccentricity from the axis of rotation _{O δ 2 (δ 1 = δ} 2 = δ) plane circular eccentric portion 42b of the axis (second axis) O ₂ as the center axis of the eccentric with a is integrally provided . The one eccentric portion 42a and the other eccentric portion 42b are arranged at a position where they are arranged in parallel around the rotation axis O with an equal interval (180 °). That is, the one eccentric portion 42a and the other of the eccentric portion 42b is equal to the distance from the distance and the axis O ₂ from the axis O ₁ to the rotational axis O to the rotation axis O, and the axis O ₁ and the axis O ₂ Are arranged around the outer periphery of the motor shaft 42 so that the distances around the rotation axis O are equal. Further, the eccentric part 42 a and the eccentric part 42 b are arranged in parallel with each other along the direction of the rotation axis O.

  At the other end of the motor shaft 42, a resolver 47 is disposed as a rotation angle detector interposed between the outer peripheral surface and the inner peripheral surface of the cylindrical portion 22b. The resolver 47 has a stator 470 and a rotor 471 and is accommodated in the third housing element 22. The stator 470 is attached to the inner peripheral surface of the cylindrical portion 22b, and the rotor 471 is attached to the outer peripheral surface of the motor shaft 42.

(Configuration of deceleration transmission mechanism 5)
FIG. 3 shows a deceleration transmission mechanism. FIG. 4 shows the air gap between the input member and the first bearing. 5A and 5B show the contact state of the input member with respect to the housing. FIG. 6 shows the support state of the input member. 3 and 4, the speed reduction transmission mechanism 5 has a pair of input members 50 and 51, a rotation force applying member 52, and an output member 53, and the rear differential 3 and the electric motor 4 (both shown in FIG. 2). Between the two. As described above, the deceleration transmission mechanism 5 decelerates the motor rotational force of the electric motor 4 and transmits the driving force to the rear differential 3.

As shown in FIGS. 4 and 6, one input member 50 is an external gear that is a gear having a center hole 50 a having an axis (third axis) O ₁ ′ as a center axis, and the other input member 51 is disposed on the side of the rear differential 3 and is rotatably supported by the motor shaft 42 with a ball bearing 54 serving as a first bearing interposed between the inner peripheral surface of the center hole 50a and the eccentric portion 42a. . An external gear that is a gear is an example of an external gear mechanism. One input member 50 receives a motor rotational force from the electric motor 4 and performs a circular motion (revolving motion around the rotation axis O) in the directions of arrows m ₁ and m ₂ (shown in FIG. 3) having an eccentricity δ. Do. The ball bearing 54 includes an inner ring 540 and an outer ring 541 as two races arranged inside and outside thereof, and a rolling element 542 that rolls between the inner ring 540 and the outer ring 541. The inner ring 540 is attached to the eccentric portion 42a, and the outer ring 541 is attached to the center hole 50a with a gap (gap) in the radial direction of the motor shaft 42, respectively. That is, the inner ring 540 is attached to the outer peripheral surface of the eccentric portion 42a, and the outer ring 541 is attached to the inner peripheral surface of the center hole 50a by clearance fitting. In FIG. 4 and FIG. 6 shows a state where the centrifugal force _{P 1} is applied to one input member 50, an inner ring 540, outer ring 541 and the rolling elements 542.

One input member 50 is provided with a plurality (six in this embodiment) of pin insertion holes (through holes) 50b arranged in parallel at equal intervals around the axis O ₁ ′. The hole diameter of the pin insertion hole 50b is set to be larger than the dimension obtained by adding the outer diameter of the needle roller bearing 55 as the second bearing to the outer diameter of the output member 53. The outer diameter of the needle roller bearing 55 is set to be smaller than the outer diameter of the ball bearing 54. On the outer peripheral surface of one input member 50, external teeth 50c having an involute tooth profile are provided.

The outer teeth 50c have two tooth surfaces (torque transmission / reception surfaces on both sides in the circumferential direction of the outer teeth 50c), and the torque transmission surfaces on one side in the circumferential direction are inner teeth (the two inner teeth adjacent to each other in the rotation force applying member 52). As the revolving force applying surface and the rotating force receiving surface for the torque transmitting / receiving surface of one of the teeth 52c, the torque receiving surface on the other side in the circumferential direction has two adjacent teeth on the inner tooth (the rotating force applying member 52). It functions as a revolving force application surface and a rotation force receiving surface with respect to the torque receiving surface of the other inner tooth) 52c. Number of teeth _{Z 1} of the external teeth 50c is set to, for example, _Z 1 = 195.

On one end face (end face on the rear differential 3 side) of one input member 50, an annular convex part (first convex part) 50d protruding toward the rear differential 3 along the third axis O ₁ ′ direction is provided. It is provided integrally.

The convex portion 50d is disposed at a portion having high rigidity in the one input member 50 (for example, the inner peripheral side of the external tooth 50c). An outer peripheral surface (a fitting surface with respect to the first housing element 20) 500d of the convex portion 50d faces the inner peripheral surface 23a of the convex portion 23 of the first housing element 20, and the axis O ₁ ′ is the central axis. It is formed with a circumferential surface.

Here, as shown in FIGS. 4 to 6, the dimension L ₁ between the axis O ₁ and the axis O ₁ ′ is determined by the movement of one input member 50 on the rotation axis O and the line orthogonal to the axis O ₁ . In a state where the outer peripheral surface 500d of the convex portion 50d is in contact with the inner peripheral surface 23a of the convex portion 23 of the first housing element 20, the outer ring 541 is in the center hole 50a and the inner ring 540 is in the eccentric portion 42a. Since it is fitted with a gap in the radial direction, the diameter difference d ₁ -D ₁ between the outer diameter D ₁ of the ball bearing 54 and the inner diameter d ₁ of the center hole 50a, the inner diameter D ₂ of the ball bearing 54 and the eccentric portion The dimension {(d ₁ −D ₁ ) + (D ₂ −d ₂ ) is obtained by adding the diameter difference D ₂ −d ₂ between the outer diameter d _{2 of} 42 a and the operating clearance G ₁ of the radial internal clearance of the ball bearing 54. ) + G ₁ } less than half the dimension {(d ₁ −D ₁ ) + (D ₂₋ d ₂ ) + G ₁ } / 2 ≧ L ₁ is set.

That is, the dimension _{L 1,} the diameter difference between the inner diameter _{d 1} of the outer diameter _{D 1} and the center hole 50a of the ball bearing 54 _(d 1 _-D 1), the inner diameter _{D 2} and the eccentric portion 42a of the ball bearing 54 One input member 50 is in an initial state in which the diameter difference between the outer diameter d ₂ (D ₂ -d ₂ ) and the radial inner clearance of the ball bearing 54 is less than half of the dimension obtained by adding the operating clearance G _1. 5A and 5B, the outer peripheral surface 500d of the convex portion 50d is set to a size that comes into contact with the inner peripheral surface 23a of the convex portion 23, as shown in FIGS.

For this reason, when one input member 50 receives a load due to the centrifugal force P ₁ generated based on the circular motion and moves in that direction, the outer peripheral surface 500d of the convex portion 50d abuts on the inner peripheral surface 23a of the convex portion 23. In this contact position, the first housing element 20 receives a radial load from one input member 50. This makes it possible to load due to centrifugal force P ₁ from one of the input member 50 the inner circumferential surface 23a of the protrusion 23 of the first housing element 20 receives concentrated to the load applied by the centrifugal force P ₁ is the ball Acting on the bearing 54 (the outer ring 541 and the rolling element 542 and the rolling element 542 and the inner ring 540) is suppressed.

As shown in FIGS. 4 and 6, the other input member 51 includes an external gear that is a gear having a center hole 51 a having an axis (third axis) O ₂ ′ as a center axis, and one input member 50 is disposed on the side of the electric motor 4 and is rotatably supported by the motor shaft 42 with a ball bearing 56 serving as a first bearing interposed between the inner peripheral surface of the center hole 51a and the eccentric portion 42b. . An external gear that is a gear is an example of an external gear mechanism. The other input member 51 receives a motor rotational force from the electric motor 4 and performs a circular motion (revolving motion around the rotation axis O) in the directions of arrows m ₁ and m ₂ (shown in FIG. 3) having an eccentricity δ. Do. The ball bearing 56 includes an inner ring 560 and an outer ring 561 as two races arranged inside and outside thereof, and a rolling element 562 that rolls between the inner ring 560 and the outer ring 561. The inner ring 560 is attached to the eccentric portion 42b, and the outer ring 561 is attached to the center hole 51a with a gap (gap) in the radial direction of the motor shaft 42, respectively. That is, the inner ring 560 is attached to the outer peripheral surface of the eccentric portion 42b, and the outer ring 561 is attached to the inner peripheral surface of the center hole 51a by clearance fitting. In FIG. 4 and FIG. 6 illustrates another input member 51, an inner ring 560, a state where the centrifugal force _{P 2} is applied to the outer ring 561 and the rolling elements 562.

The other input member 51 is provided with a plurality (six in this embodiment) of pin insertion holes (through holes) 51b arranged in parallel at equal intervals around the axis O ₂ ′. The hole diameter of the pin insertion hole 51b is set to be larger than the dimension obtained by adding the outer diameter of the needle roller bearing 57 as the second bearing to the outer diameter of the output member 53. The outer diameter of the needle roller bearing 57 is set to be smaller than the outer diameter of the ball bearing 56. An outer tooth 51 c having an involute tooth profile is provided on the outer peripheral surface of the other input member 51.

The outer teeth 51c have two inner surfaces (torque transmission / reception surfaces on both sides in the circumferential direction of the outer teeth 51c), and the torque transmission surfaces on one side in the circumferential direction are inner teeth (two inner teeth adjacent to each other in the rotation force applying member 52). As the revolving force applying surface and the rotating force receiving surface for the torque transmitting / receiving surface of one of the teeth 52c, the torque receiving surface on the other side in the circumferential direction has two adjacent teeth on the inner tooth (the rotating force applying member 52). It functions as a revolving force application surface and a rotation force receiving surface with respect to the torque transmitting / receiving surface of the other inner tooth) 52c. Number of teeth _{Z 2} of the external teeth 51c is set to, for example, _Z 2 = 195.

On one end face (end face of the electric motor 4) of the other input member 51, an annular convex portion (first convex portion) 51d that protrudes toward the electric motor 4 along the third axis O ₂ ′ direction is provided. It is provided integrally.

The convex portion 51d is disposed at a portion having high rigidity in the other input member 51 (for example, the inner peripheral side of the external tooth 50c). An outer peripheral surface (a fitting surface with respect to the second housing element 21) 510d of the convex portion 51d is opposed to the inner peripheral surface 27a of the convex portion 27 of the second housing element 21, and has a central axis line as an axis O ₂ ′. It is formed with a circumferential surface.

Here, as shown in FIGS. 4 to 6, the dimension L ₂ between the axis O ₂ and the axis O ₂ ′ is determined by the movement of the other input member 51 on the rotation axis O and the line orthogonal to the axis O ₂ . In a state where the outer peripheral surface 510d of the convex portion 51d is in contact with the inner peripheral surface 27a of the convex portion 27 of the second housing element 21, the outer ring 561 is in the center hole 51a and the inner ring 560 is in the eccentric portion 42b. Since it is fitted with a gap in the radial direction, the diameter difference d ₃ -D ₃ between the outer diameter D ₃ of the ball bearing 56 and the inner diameter d ₃ of the center hole 51a, the inner diameter D ₄ of the ball bearing 56 and the eccentric portion the diameter difference _D 4 -d _4, and the sum of the running clearance _{G 2} of the radial internal clearance of the ball bearing 56 dimension between the outer diameter _{d 4} of _{42b {(d 3 -D 3)} + (D 4 -d 4 ) + less than half the size of _{G 2} {(d 3 -D} 3) + (D ₄ −d ₄ ) + G ₂ } / 2 ≧ L ₂ .

That is, the dimension _{L 2,} the diameter difference between the outer diameter _{D 3} and the inner diameter _{d 3} of the central hole 51a of the ball bearing 56 _(d 3 _-D 3), the inner diameter _{D 4} of the ball bearing 56 and the eccentric portion 42b In the initial state, the other input member 51 has a dimension that is less than half the dimension obtained by adding the diameter difference from the outer diameter d ₄ (D ₄ -d ₄ ) and the operating clearance G ₂ of the radial internal clearance in the ball bearing 56. 5A and 5B, the outer peripheral surface 510d of the convex portion 51d is set to a size that abuts on the inner peripheral surface 27a of the convex portion 27, as shown in FIGS.

Therefore, when you move in that direction under a load and the other of the input member 51 due to the centrifugal force P ₂ generated on the basis of the circular motion, the outer circumferential surface 510d of the protrusion 51d comes into contact with the inner peripheral surface 27a of the protrusion 27 In this contact position, the second housing element 21 receives a radial load from the other input member 51. This makes it possible to receive the load caused by the centrifugal force P ₂ from the other input member 51 the inner circumferential surface 27a is concentrated in the convex portion 27 in the second housing element 21, a load due to the centrifugal force P ₂ is the ball Acting on the bearing 56 (the outer ring 561 and the rolling element 562 and the rolling element 562 and the inner ring 560) is suppressed.

As shown in FIG. 4, the rotation force imparting member 52 includes an internal gear that is a gear having a fourth axis (in the present embodiment, the fourth axis coincides with the rotation axis O) as a central axis. The first housing element 20 and the second housing element 21 are disposed between the first housing element 20 and the second housing element 21. The whole is formed by a bottomless cylindrical member that opens in both directions of the rotation axis O and forms a part of the housing 2. Yes. An internal gear that is a gear is an example of an internal gear mechanism. The rotation force applying member 52 meshes with the pair of input members 50 and 51, and receives the rotation force in the directions of the arrows n ₁ and n _{2 on one} input member 50 that revolves by receiving the motor rotation force of the electric motor 4. Further, rotational forces in the directions of the arrows l ₁ and l ₂ are applied to the other input member 51, respectively.

  A first fitting portion 52 a that fits to the outer peripheral surface 23 b of the convex portion 23 and a second fitting portion 52 b that fits to the outer peripheral surface 27 b of the convex portion 27 are formed on the inner peripheral surface of the rotation force applying member 52. Are provided in the direction of the rotation axis O with a predetermined interval. Further, the external teeth 50c of one input member 50 and the other input member are interposed on the inner peripheral surface of the rotation force applying member 52 between the first fitting portion 52a and the second fitting portion 52b. An involute tooth-shaped inner tooth 52 c that meshes with the outer tooth 51 c of 51 is provided.

The inner tooth 52c has a torque transfer surface on one side in the circumferential direction among the both tooth surfaces (the torque transfer surfaces on both sides in the circumferential direction of the inner tooth 52c), and the external teeth (the two external teeth adjacent to each other in the input member 50). As one of the external teeth) 50c torque transfer surface and external teeth (one of the two external teeth adjacent to each other in the input member 51) 51c as a rotational force application surface and a revolving force application surface. Further, the torque transmitting / receiving surface on the other side in the circumferential direction has two external teeth (the other external tooth of two external teeth adjacent to each other in the input member 50) 50c and the external teeth (two adjacent to each other in the input member 51). It functions as a rotation force application surface and a revolving force application surface with respect to the torque transmission / reception surface of the other external tooth) 51c. Number of teeth _{Z 3} of the internal teeth 52c is set to, for example, _Z 3 = 208. Accordingly, the reduction ratio α of the deceleration transmission mechanism 5 is calculated from α = Z ₂ / (Z ₃ −Z ₂ ).

  As shown in FIG. 4, the output member 53 includes a plurality of (six in this embodiment) bolts having a threaded portion 53a at one end and a head 53b at the other end. The threaded portion 53 a is attached to the pin attachment hole 300 c of the differential case 30 through the pin insertion hole 50 b of the input member 50 and the pin insertion hole 51 b of the other input member 51. Further, the output member 53 is disposed by inserting an annular spacer 58 interposed between the head 53b and the other input member 51. The output member 53 receives the rotation force applied by the rotation force applying member 52 from the pair of input members 50 and 51 and outputs the rotation force to the differential case 30 as its rotational force.

  The contact resistance between the outer peripheral surface of the output member 53 and the inner peripheral surface of the pin insertion hole 50b in one input member 50 is reduced at a portion interposed between the screw portion 53a and the head portion 53b. Needle roller bearings 55 for reducing contact resistance with the inner peripheral surface of the pin insertion hole 51b of the other input member 51 are attached.

  The needle roller bearing 55 is a race 550 that can contact the inner peripheral surface of the plurality of pin insertion holes 50 b in one input member 50, and a needle shape that rolls between the race 550 and the outer peripheral surface of the output member 53. There are rollers 551. The needle roller bearing 57 has a race 570 that can contact the inner peripheral surface of the plurality of pin insertion holes 51 b in the other input member 51, and a needle shape that rolls between the race 570 and the outer peripheral surface of the output member 53. It has rollers 571.

(Operation of the motor rotational force transmission device 1)
Next, the operation of the motor torque transmission device shown in the present embodiment will be described with reference to FIGS.

  In FIG. 2, when electric power is supplied to the electric motor 4 of the motor rotational force transmission device 1 to drive the electric motor 4, this motor rotational force is applied to the deceleration transmission mechanism 5 via the motor shaft 42, and the deceleration transmission mechanism 5. Operates.

Therefore, the speed reduction transmission mechanism 5 performs circular motion with a eccentricity δ is the input member 50, 51 in the arrow m ₁ direction shown in FIG. 3, for example.

Accordingly, the input member 50 is the axis _{O 1} while meshing with the internal teeth 52c of the outer teeth 50c rotation force applying member 52 counterclockwise (the arrow _{n 1} direction shown in FIG. 3), also the input member 51 outer teeth 51c the rotates respectively with the internal teeth 52c on around the axis O ₂ while meshing rotation force applying member 52 (arrow l ₁ direction shown in FIG. 3). In this case, due to the rotation of the input members 50 and 51, the inner peripheral surface of the pin insertion hole 50b is in the race 550 of the needle roller bearing 55, and the inner peripheral surface of the pin insertion hole 51b is in the race 570 of the needle roller bearing 57, respectively. Abut.

  For this reason, the revolution movement of the input members 50 and 51 is not transmitted to the output member 53, but only the rotation movement of the input members 50 and 51 is transmitted, and the rotation force of the input members 50 and 51 is transmitted from the output member 53 to the differential case 30. It is output as the rotational force.

  As a result, the rear differential 3 is operated, and the driving force based on the motor rotational force of the electric motor 4 is distributed to the rear axle shaft 106 in FIG. 1 and transmitted to the left and right rear wheels 105.

Here, in the motor rotational force transmission device 1, the centrifugal force P ₁ is applied to the input member 50 based on the circular motion and the centrifugal force P ₂ is applied to the input member 51 based on the circular motion. .

Accordingly, the input member 50 in the direction of action of the centrifugal force P ₁ (e.g., the lower part of FIG. 6), also the input member 51 respectively move in the direction of action of the centrifugal force P ₂ (e.g., upward in FIG. 6).

In this case, as shown in FIGS. 4 to 6, when one input member 50 receives a load due to the centrifugal force P ₁ generated based on the circular motion and moves in that direction, the outer diameter D ₁ of the ball bearing 54 and Diameter difference (d ₁ -D ₁ ) between the inner diameter d ₁ of the center hole 50 a and diameter difference (D ₂ -d ₂ ) between the inner diameter D ₂ of the ball bearing 54 and the outer diameter d ₂ of the eccentric portion 42 a. and before moving half following dimensions dimensions obtained by adding the running clearance G ₁ of the radial internal clearance in the ball bearing 54, the outer peripheral surface 500d of the protrusion 50d as shown in FIG. 5 (a) and (b) It abuts on the inner peripheral surface 23 a of the convex portion 23.

For this reason, the inner peripheral surface 23 a of the convex portion 23 receives the load caused by the centrifugal force P ₁ from one input member 50 in a concentrated manner, and the load caused by the centrifugal force P ₁ acts on the ball bearing 54. It is suppressed.

Similarly, during the movement in that direction under load by centrifugal force P ₂ which is the other of the input member 51 occurring on the basis of the circular motion, the outer diameter D ₃ and the inner diameter d ₃ of the central hole 51a of the ball bearing 56 Diameter difference (d ₃ -D ₃ ), the diameter difference (D ₄ -d ₄ ) between the inner diameter D ₄ of the ball bearing 56 and the outer diameter d ₄ of the eccentric portion 42 b, and the operation of the radial internal clearance in the ball bearing 56 before moving half following dimensions of obtained by adding the gap G _2, the outer circumferential surface 510d of the protrusion 51d as shown in FIG. 5 (a) and (b) abuts against the inner peripheral surface 27a of the protrusion 27 .

For this reason, the inner peripheral surface 27 a of the convex portion 27 receives the load caused by the centrifugal force P ₂ from the other input member 51 in a concentrated manner, and the load caused by the centrifugal force P ₂ acts on the ball bearing 56. It is suppressed.

  Therefore, in the present embodiment, it is not necessary to use highly durable bearings for the ball bearings 54 and 56.

In the above embodiment has described the case where the input member 50, 51 by circular motion of the arrow m ₁ direction to actuate the motor torque transmission device 1, to indicate the input member 50, 51 in FIG. 3 the motor torque transmission device 1 also by circular motion in the arrow m ₂ direction can be operated as in the above embodiment to. In this case, the rotation of the input member 50 is performed in the direction of the arrow n ₂ , and the rotation of the input member 51 is performed in the direction of the arrow l ₂ .

[Effect of the first embodiment]
According to the first embodiment described above, the following effects can be obtained.

(1) Since the load due to the centrifugal force P ₁ from the input member 50 is suppressed from acting on the ball bearing 54 and the load due to the centrifugal force P ₂ from the input member 51 is suppressed from acting on the ball bearing 56, respectively. , 56 is not required to use a highly durable bearing, and the cost can be reduced.

(2) The suppression of the action of the load by the centrifugal force P ₁ on the ball bearing 54 and the action of the load by the centrifugal force P _{2 on} the ball bearing 56 can also increase the life of the ball bearings 54 and 56. .

In the present embodiment, one input member 50 has an annular convex portion 50d protruding toward the rear differential 3 along the axis O ₁ ′ direction, and the other input member 51 has an axis O ₂ ′ direction. However, the present invention is not limited to this, as shown in FIG. 7 (Modification 1). It is good also as a structure.

(Modification 1)
In FIG. 7, an annular convex portion (first convex portion) 50 e protruding in a direction orthogonal to the axis O ₁ ′ is provided at the end portion of one input member 50 on the rear differential 3 side, and the other input member 51 is provided. Each of the electric motor 4 side end portions is provided with an annular convex portion (first convex portion) 51e protruding in a direction orthogonal to the axis O ₂ ′.

One end (left side in FIG. 7) of the rotation force applying member 52 projects in a direction orthogonal to the rotation axis O, and the load caused by the centrifugal force P ₁ generated by the _one input member 50 based on the circular motion is applied. An annular convex portion 52d having an inner peripheral surface 520d that contacts the outer peripheral surface 500e of the convex portion (second convex portion) 50e in the received state is provided. On the other side (in FIG. 7 right) end of the rotation force applying member 52, a load due to the centrifugal force P ₂ arising under protrudes in a direction perpendicular to the rotation axis O, and the other input member 51 to the circular motion An annular convex portion (second convex portion) 52e having an inner peripheral surface 520e that contacts the outer peripheral surface 510e of the convex portion 51e in the received state is provided.

  In the present embodiment, an annular convex portion 50d having an outer peripheral surface 500d fitted to the inner peripheral surface 23a of the first housing element 20 convex portion 23 is provided on one input member 50, and the second housing element. Although the case where each of the input members 51 is provided with an annular convex portion 51d having an outer peripheral surface 510d fitted to the inner peripheral surface 27a of the twenty-first convex portion 27, the present invention is limited to this. Instead, a structure as shown in FIG. 8 (Modification 2) may be used.

(Modification 2)
In FIG. 8, an annular convex portion (second convex portion) 28 protruding toward the electric motor 4 along the rotation axis O direction is provided at the end portion of the first housing element 20 on the electric motor 4 side. An annular convex portion (second convex portion) 29 protruding toward the rear differential 3 side along the rotation axis O direction is integrally provided at the end portion of the second housing element 21 on the rear differential 3 side.

  A convex portion (first convex portion) 50f having an inner peripheral surface 500f fitted to the outer peripheral surface 28a of the convex portion 28 of the first housing element 20 is provided at the end portion on the rear differential 3 side of one input member 50. Further, a convex portion (first convex portion) 51f having an inner peripheral surface 510f fitted to the outer peripheral surface 29a of the convex portion 29 of the second housing element 21 is provided at the end of the other input member 51 on the electric motor 4 side. Each is provided integrally.

[Second Embodiment]
Next, a speed reduction mechanism in a motor torque transmission device according to a second embodiment of the present invention will be described with reference to FIGS. 4, 5A, 5B, and 9. FIG. FIG. 9 shows the support state of the input member. 9, the same or equivalent members as those in FIG. 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIGS. 4 and 9, in the speed reduction transmission mechanism 100 (partially shown) according to the second embodiment of the present invention, the inner rings 540 and 560 of the ball bearings 54 and 56 are formed of the eccentric portions 42a and 42b. It is characterized in that the outer ring 541 and 561 are attached to the outer peripheral surface by interference fit and the inner ring 50a, 51a is attached to the inner peripheral surface by clearance fit.

The dimension L ₁ between the axis O ₁ and the axis O ₁ ′ is such that the outer peripheral surface 500d of the convex portion 50d is moved to the first housing element by the movement of one input member 50 on the rotation axis O and the line orthogonal to the axis O _1. in contact with the state on the inner peripheral surface 23a of the protrusion 23 of the 20, because it is fitted with a gap in the radial direction of the motor shaft 42 the outer ring 541 to the center hole 50a, the outer diameter D ₁ and the center hole of the ball bearing 54 the diameter difference _d 1 -D _1, and dimensions obtained by adding the running clearance _{G 1} of the radial internal clearance of the ball bearing 54 is less than half the size of the _{{(d 1 -D 1) +} G 1} between the inner diameter _{d 1} of 50a {(D ₁ −D ₁ ) + G ₁ } / 2 ≧ L ₁ is set.

That is, as the dimension L ₁ , the diameter difference (d ₁ -D ₁ ) between the outer diameter D ₁ of the ball bearing 54 and the inner diameter d ₁ of the center hole 50 a and the operating clearance G of the radial internal clearance in the ball bearing 54. Before one input member 50 moves from its initial state to a dimension that is less than half the dimension obtained by adding ₁ , the outer peripheral surface 500d of the convex portion 50d is formed of the convex portion 23 as shown in FIGS. The dimension is set to abut against the inner peripheral surface 23a.

For this reason, when one input member 50 receives a load due to the centrifugal force P ₁ generated based on the circular motion and moves in that direction, the outer peripheral surface 500d of the convex portion 50d abuts on the inner peripheral surface 23a of the convex portion 23. In this contact position, the first housing element 20 receives a radial load from one input member 50. This makes it possible to load due to centrifugal force P ₁ from one of the input member 50 the inner circumferential surface 23a of the protrusion 23 of the first housing element 20 receives concentrated to the load applied by the centrifugal force P ₁ is the ball Acting on the bearing 54 (the outer ring 541 and the rolling element 542 and the rolling element 542 and the inner ring 540) is suppressed.

The dimension L ₂ between the axis O ₂ and the axis O ₂ ′ is such that the outer peripheral surface 510 d of the convex portion 51 d is moved to the second housing element by the movement of the other input member 51 on the rotation axis O and the line orthogonal to the axis O _2. in 21 abuts state with the inner peripheral surface 27a of the protrusion 27 of, because it is fitted with a gap in the radial direction of the motor shaft 42 the outer ring 561 to the center hole 51a, the outer diameter D ₃ of the ball bearing 56 and the center hole A dimension {less than half the dimension {(d ₃ -D ₃ ) + G ₂ } of the diameter difference d ₃ -D ₃ between the inner diameter d _{3 of} 50a and the operating clearance G ₂ of the internal clearance of the ball bearing 54 { (D ₃ −D ₃ ) + G ₂ } / 2 ≧ L ₂ is set.

That is, as the dimension L ₂ , the diameter difference (d ₃ −D ₃ ) between the outer diameter D ₃ of the ball bearing 56 and the inner diameter d ₃ of the center hole 51 a and the operating clearance G of the radial internal clearance in the ball bearing 56. Before the other input member 51 moves from its initial state to a dimension that is less than or equal to half the dimension obtained by adding ₂ to the outer peripheral surface 510d of the convex portion 27 as shown in FIGS. 5 (a) and 5 (b). The dimension is set so as to contact the inner peripheral surface 27a.

Therefore, when you move in that direction under a load and the other of the input member 51 due to the centrifugal force P ₂ generated on the basis of the circular motion, the outer circumferential surface 510d of the protrusion 51d comes into contact with the inner peripheral surface 27a of the protrusion 27 In this contact position, the second housing element 21 receives a radial load from the other input member 51. This makes it possible to receive the load caused by the centrifugal force P ₂ from the other input member 51 the inner circumferential surface 27a is concentrated in the convex portion 27 in the second housing element 21, a load due to the centrifugal force P ₂ is the ball Acting on the bearing 56 (the outer ring 561 and the rolling element 562 and the rolling element 562 and the inner ring 560) is suppressed.

[Effect of the second embodiment]
According to the second embodiment described above, the same effects as those shown in the first embodiment can be obtained.

[Third embodiment]
Next, a speed reduction mechanism in a motor torque transmission device according to a third embodiment of the present invention will be described with reference to FIGS. 4, 5A, 5B, and 10. FIG. FIG. 10 shows the support state of the input member. 10, the same or equivalent members as those in FIG. 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIGS. 4 and 10, in the speed reduction transmission mechanism 200 (partially shown) according to the third embodiment of the present invention, the inner rings 540, 560 of the ball bearings 54, 56 are eccentric parts 42 a, 42 b. It is characterized in that the outer rings 541 and 561 are attached to the outer peripheral surface by clearance fit and the inner peripheral surfaces of the center holes 50a and 51a by interference fit.

The dimension L ₁ between the axis O ₁ and the axis O ₁ ′ is such that the outer peripheral surface 500d of the convex portion 50d is moved to the first housing element by the movement of one input member 50 on the rotation axis O and the line orthogonal to the axis O _1. in contact with the state on the inner peripheral surface 23a of the protrusion 23 of the 20, because the inner ring 540 is fitted with a gap in the radial direction of the motor shaft 42 to the eccentric portion 42a, the eccentric portion 42a and the inner diameter D ₂ of the ball bearing 54 Less than half of the dimension {(D ₂ -d ₂ ) + G ₁ } obtained by adding the diameter difference D ₂ -d _{2 from} the outer diameter d ₂ and the radial internal clearance of the ball bearing 54 to the operating clearance G ₁ {(D ₂ −d ₂ ) + G ₁ } / 2 ≧ L ₁ is set.

That is, as the dimension L ₁ , the diameter difference (D ₂ −d ₂ ) between the inner diameter D ₂ of the ball bearing 54 and the outer diameter d ₂ of the eccentric portion 42 a and the operating clearance G of the radial internal clearance in the ball bearing 54. Before one input member 50 moves from its initial state to a dimension that is less than or equal to half of the dimension obtained by adding ₁ , the outer peripheral surface 500d of the convex portion 50d is the convex portion 23 as shown in FIGS. 5 (a) and 5 (b). The dimension is set so as to abut against the inner peripheral surface 23a.

For this reason, when one input member 50 receives a load due to the centrifugal force P ₁ generated based on the circular motion and moves in that direction, the outer peripheral surface 500d of the convex portion 50d abuts on the inner peripheral surface 23a of the convex portion 23. In this contact position, the first housing element 20 receives a radial load from one input member 50. This makes it possible to load due to centrifugal force P ₁ from one of the input member 50 the inner circumferential surface 23a of the protrusion 23 of the first housing element 20 receives concentrated to the load applied by the centrifugal force P ₁ is the ball Acting on the bearing 54 (the outer ring 541 and the rolling element 542 and the rolling element 542 and the inner ring 540) is suppressed.

The dimension L ₂ between the axis O ₂ and the axis O ₂ ′ is such that the outer peripheral surface 510 d of the convex portion 51 d is moved to the second housing element by the movement of the other input member 51 on the rotation axis O and the line orthogonal to the axis O _2. in 21 abuts state with the inner peripheral surface 27a of the protrusion 27 of, for inner ring 560 is fitted with a gap in the radial direction of the motor shaft 42 to the eccentric portion 42b, the eccentric portion 42b and the inner diameter D ₄ of the ball bearing 56 Less than half of the dimension {(D ₄ -d ₄ ) + G ₂ } obtained by adding the difference D ₄ -d ₄ between the outer diameter d ₄ and the operating clearance G ₂ of the radial internal clearance of the ball bearing 56. {(D ₄ −d ₄ ) + G ₂ } / 2 ≧ L ₂ is set.

That is, as the dimension L ₂ , the diameter difference (D ₄ −d ₄ ) between the inner diameter D ₄ of the ball bearing 56 and the outer diameter d ₄ of the eccentric portion 42 b and the operating clearance G of the radial internal clearance in the ball bearing 56. less than half the size of the dimension plus ₂ before the other input member 51 to move from its initial state, FIG. 5 (a) and the outer peripheral surface of the projection 51d, as shown in (b) 510 d convex portion 27 The dimension is set so as to be in contact with the inner peripheral surface 27a.

Therefore, when you move in that direction under a load and the other of the input member 51 due to the centrifugal force P ₂ generated on the basis of the circular motion, the outer circumferential surface 510d of the protrusion 51d comes into contact with the inner peripheral surface 27a of the protrusion 27 In this contact position, the second housing element 21 receives a radial load from the other input member 51. This makes it possible to receive the load caused by the centrifugal force P ₂ from the other input member 51 the inner circumferential surface 27a is concentrated in the convex portion 27 in the second housing element 21, a load due to the centrifugal force P ₂ is the ball Acting on the bearing 56 (the outer ring 561 and the rolling element 562 and the rolling element 562 and the inner ring 560) is suppressed.

[Effect of the third embodiment]
According to the third embodiment described above, the same effects as those shown in the first embodiment can be obtained.

[Fourth embodiment]
Next, a speed reduction mechanism in a motor torque transmission device according to a fourth embodiment of the present invention will be described with reference to FIGS. 4, 5 </ b> A, 5 </ b> B, and 11. FIG. 11 shows the support state of the input member. 11, the same or equivalent members as in FIG. 6 are given the same reference numerals, and detailed descriptions thereof are omitted.

  As shown in FIGS. 4 and 11, the speed reduction transmission mechanism 300 (partially shown) according to the fourth embodiment of the present invention has inner rings 540 and 560 of ball bearings 54 and 56 of eccentric portions 42 a and 42 b. It is characterized in that the outer rings 541 and 561 are attached to the outer peripheral surface and the inner peripheral surfaces of the center holes 50a and 51a by an interference fit.

The dimension L ₁ between the axis O ₁ and the axis O ₁ ′ is such that the outer peripheral surface 500d of the convex portion 50d is moved to the first housing element by the movement of one input member 50 on the rotation axis O and the line orthogonal to the axis O _1. in contact with the state on the inner peripheral surface 23a of the protrusion 23 of the 20 it is set to a dimension G _1/2 ≧ L ₁ less than half the operating clearance G ₁ of the internal clearance of the ball bearing 54.

That is, the dimension L _1, before radial clearance one input member 50 to less than half the size of the operating clearance G ₁ of the ball bearing 54 is moved from its initial state, FIG. 5 (a) and (b) As shown in FIG. 5, the outer peripheral surface 500d of the convex portion 50d is set to a size that comes into contact with the inner peripheral surface 23a of the convex portion 23.

For this reason, when one input member 50 receives a load due to the centrifugal force P ₁ generated based on the circular motion and moves in that direction, the outer peripheral surface 500d of the convex portion 50d abuts on the inner peripheral surface 23a of the convex portion 23. In this contact position, the first housing element 20 receives a radial load from one input member 50. This makes it possible to load due to centrifugal force P ₁ from one of the input member 50 the inner circumferential surface 23a of the protrusion 23 of the first housing element 20 receives concentrated to the load applied by the centrifugal force P ₁ is the ball Acting on the bearing 54 (the outer ring 541 and the rolling element 542 and the rolling element 542 and the inner ring 540) is suppressed.

The dimension L ₂ between the axis O ₂ and the axis O ₂ ′ is such that the outer peripheral surface 510 d of the convex portion 51 d is moved to the second housing element by the movement of the other input member 51 on the rotation axis O and the line orthogonal to the axis O _2. in 21 abuts state with the inner peripheral surface 27a of the protrusion 27 of, and is set to a dimension G _2/2 ≧ L ₂ less than half the operating clearance G ₂ of internal clearance of the ball bearing 56.

That is, as the dimension L ₂ , before the other input member 51 moves from its initial state, the dimension less than half of the radial internal clearance operating clearance G ₂ in the ball bearing 56 is shown in FIGS. As shown in FIG. 5, the outer peripheral surface 510d of the convex portion 51d is set to a size that comes into contact with the inner peripheral surface 27a of the convex portion 27.

Therefore, when you move in that direction under a load and the other of the input member 51 due to the centrifugal force P ₂ generated on the basis of the circular motion, the outer circumferential surface 510d of the protrusion 51d comes into contact with the inner peripheral surface 27a of the protrusion 27 In this contact position, the second housing element 21 receives a radial load from the other input member 51. This makes it possible to receive the load caused by the centrifugal force P ₂ from the other input member 51 the inner circumferential surface 27a is concentrated in the convex portion 27 in the second housing element 21, a load due to the centrifugal force P ₂ is the ball Acting on the bearing 56 (the outer ring 561 and the rolling element 562 and the rolling element 562 and the inner ring 560) is suppressed.

[Effect of the fourth embodiment]
According to the fourth embodiment described above, the same effects as those shown in the first embodiment can be obtained.

  As mentioned above, although the deceleration mechanism of this invention and the motor rotational force transmission apparatus provided with this were demonstrated based on said embodiment, this invention is not limited to said embodiment, It deviates from the summary. The present invention can be carried out in various modes as long as it is not, for example, the following modifications are possible.

(1) In the above embodiment, the distance from the axis O ₁ to the rotation axis O is equal to the distance from the axis O ₂ to the rotation axis O, and around the rotation axis O between the axis O ₁ and the axis O _2. One eccentric portion 42a and the other eccentric portion 42b are provided on the outer peripheral surface of the motor shaft 42 so as to equalize the distance between the motor shaft 42 and the motor shaft 42 of the electric motor 4 about its axis (rotation axis O). Although the case where the pair of input members 50 and 51 are arranged at portions spaced apart from each other at equal intervals (180 °) has been described, the present invention is not limited to this, and the number of input members can be changed as appropriate. .

  That is, when there are n (n ≧ 3) input members, in the virtual plane orthogonal to the axis of the electric motor (motor shaft), the axis of the first eccentric part, the axis of the second eccentric part,. Assuming that the axis of the nth eccentric part is sequentially arranged in one direction around the axis of the motor shaft, the distance from the axis of each eccentric part to the axis of the motor shaft is equal, and the first eccentric part, Each of the eccentric portions is formed so that the included angle formed by a line segment connecting the axes of the two eccentric portions adjacent to each other among the two eccentric portions,..., The n-th eccentric portion and the axis of the motor shaft is 360 ° / n. Arranged on the outer periphery of the motor shaft, n input members are arranged on the motor shaft at portions spaced apart by 360 ° / n around the axis.

  For example, when there are three input members, the axis of the first eccentric part, the axis of the second eccentric part, and the axis of the third eccentric part are on the motor axis on a virtual plane orthogonal to the axis of the motor shaft. If it is sequentially arranged in one direction around the axis, the distance from the axis of each eccentric part to the axis of the motor shaft is equal, and the first eccentric part, the second eccentric part, and the third eccentric part Each eccentric part is arranged on the outer periphery of the motor shaft so that the included angle formed by the line connecting the axis of two eccentric parts adjacent to each other and the axis of the motor shaft is 120 °, and three inputs The members are arranged on the motor shaft at portions spaced apart by 120 ° around the axis.

(2) In the above embodiment, the case where the present invention is applied to the four-wheel drive vehicle 101 using both the engine 102 and the electric motor 4 as the drive source has been described. However, the present invention is not limited to this, and only the electric motor is used as the drive source. The present invention can also be applied to an electric vehicle that is a four-wheel drive vehicle or a two-wheel drive vehicle. The present invention can also be applied to a four-wheel drive vehicle having an engine, a first drive shaft by an electric motor, and a second drive shaft by an electric motor, as in the above embodiment.

(3) In the above embodiment, the ball bearings 54 and 56, which are deep groove ball bearings, are provided between the inner peripheral surfaces of the center holes 50a and 51a of the input members 50 and 51 and the outer peripheral surfaces of the eccentric portions 42a and 42b, respectively. Although the case where the input members 50 and 51 are rotatably supported with respect to the eccentric portions 42a and 42b has been described, the present invention is not limited to this, and the deep groove ball bearing is used instead of the deep groove ball bearing. A ball bearing or a roller bearing other than the bearing may be used as the first bearing. Examples of such ball bearings and roller bearings include angular contact ball bearings, needle roller bearings, rod roller bearings, cylindrical roller bearings, tapered roller bearings, and self-aligning roller bearings. Moreover, as a 1st bearing of this invention, it may replace with a rolling bearing and may use a sliding bearing.

  For example, as shown in FIGS. 12 to 15, a cylindrical roller bearing 500 (inner ring 501, outer ring 502, rolling element 503) and a cylindrical roller bearing 600 (inner ring 601, outer ring 602, rolling element 603) are used as the first bearing. In this case, one input member 50 is rotatably supported by the eccentric portion 42a via the cylindrical roller bearing 500, and the other input member 51 is rotatably supported by the eccentric portion 42b via the cylindrical roller bearing 600. In this case, FIG. 12 corresponds to FIG. 6, FIG. 13 corresponds to FIG. 9, FIG. 14 corresponds to FIG. 10, and FIG. 12-15, instead of the ball bearing 54 shown in the above embodiment, a cylindrical roller bearing 500 is provided between the inner peripheral surface of the center hole 50a of one input member 50 and the outer peripheral surface of the eccentric portion 42a. Further, instead of the ball bearing 56 shown in the above embodiment, a cylindrical roller bearing 600 is disposed between the inner peripheral surface of the center hole 51a of the other input member 51 and the outer peripheral surface of the eccentric portion 42b.

(4) In the above-described embodiment, the outer peripheral surface of the output member 53 can be brought into contact with the inner peripheral surface of the pin insertion hole 50b of the input member 50 at a portion interposed between the screw portion 53a and the head portion 53b. When the needle roller bearing 55 as the second bearing and the needle roller bearing 57 as the second bearing that can contact the inner peripheral surface of the pin insertion hole 51b of the input member 51 are respectively attached. Although demonstrated, this invention is not limited to this, It may replace with a needle roller bearing and may use roller bearings and ball bearings other than a needle roller bearing. Examples of such ball bearings and roller bearings include deep groove ball bearings, angular ball bearings, cylindrical roller bearings, rod roller bearings, tapered roller bearings, and self-aligning roller bearings. Further, as the second bearing of the present invention, a sliding bearing may be used instead of the rolling bearing.

(5) In the above embodiment, when the pair of input members 50 and 51 are arranged around the rotation axis O at equal intervals around the outer periphery of the motor shaft 42, that is, the rotation axis of the motor shaft 42 (first The axis between the second axis O ₁ and the third axis O ₁ ′ when the axis O and the axis (fourth axis) of the rotation force applying member 52 coincide with each other, and the second axis Although an example has been described in which the dimension between O ₂ and the third axis O ₂ ′ is set to a predetermined dimension, the present invention is not limited to this, and a single input member is a motor shaft. Are arranged around the outer periphery of the motor shaft, or when a plurality of input members are arranged around the rotational axis of the motor shaft at unequal intervals, that is, the first axis and the fourth axis are Even if they do not match, the dimension between the second axis and the third axis is the predetermined dimension. Method (less than half of the dimension including the difference in diameter between the outer diameter of the bearing and the inner diameter of the center hole, the difference in diameter between the inner diameter of the bearing and the outer diameter of the eccentric part, and the operating clearance of the radial internal clearance of the bearing) It is possible to carry out similarly to the above-described embodiment.

(6) In the above embodiment, a reduction mechanism using an external gear that is a gear as the external gear mechanism, and an internal gear that is a gear as the internal gear mechanism, and a motor torque transmission device including the reduction mechanism However, the present invention is not limited to this. For example, a disk-shaped curved plate having a plurality of waveforms composed of trochoidal curves such as epitrochoid on the outer peripheral portion as an external gear mechanism. A plurality of external pins may be used as the internal gear mechanism. In this case, it goes without saying that the number of teeth of the external gear mechanism is the number of waveforms of the curved plate, and the number of teeth of the internal gear mechanism is the number of external pins. It goes without saying that a cycloid speed reducer is included as a speed reduction mechanism using such a curved plate and using an outer pin.

DESCRIPTION OF SYMBOLS 1 ... Motor rotational force transmission apparatus, 2 ... Housing, 20 ... 1st housing element, 20a ... Shaft penetration hole, 21 ... 2nd housing element, 21a ... Inner flange, 22 ... 3rd housing element, 22a ... Shaft Insertion hole, 22b ... cylindrical portion, 23 ... convex portion, 23a ... inner peripheral surface, 23b ... outer peripheral surface, 24 ... sealing member, 25 ... annular member, 27 ... convex portion, 27a ... inner peripheral surface, 27b ... outer peripheral surface 28 ... convex portion, 28a ... outer peripheral surface, 29 ... convex portion, 29a ... outer peripheral surface, 3 ... rear differential, 30 ... differential case, 30a ... accommodation space, 30b ... shaft insertion hole, 30c ... flange, 300c ... pin mounting hole 31 ... Pinion gear shaft, 32 ... Pinion gear, 33 ... Side gear, 33a ... Shaft coupling hole, 34, 35 ... Ball bearing, 36 ... Pin, 4 ... Electric motor , 40 ... stator, 41 ... rotor, 42 ... motor shaft, 42a, 42b ... eccentric part, 43 ... bolt, 44 ... ball bearing, 45 ... sleeve, 46 ... ball bearing, 47 ... resolver, 470 ... stator, 471 ... Rotor, 5 ... Deceleration transmission mechanism, 50, 51 ... Input member, 50a, 51a ... Center hole, 50b, 51b ... Pin insertion hole, 50c, 51c ... External teeth, 50d ... Convex part, 500d ... Outer peripheral surface, 51d ... Convex Part, 510d ... outer peripheral surface, 50e, 51e ... convex part, 500e, 510e ... outer peripheral surface, 50f, 51f ... convex part, 500f, 510f ... inner peripheral surface, 52 ... autorotation force imparting member, 52a ... first fitting Part, 52b ... second fitting part, 52c ... inner teeth, 52d, 52e ... convex part, 520d, 520e ... inner peripheral surface, 53 ... output member, 53a ... screw part, 53b ... head, 54 ... ball bearing 540 ... inner ring, 41 ... outer ring, 542 ... rolling element, 55 ... needle roller bearing, 550 ... race, 551 ... needle roller, 56 ... ball bearing, 560 ... inner ring, 561 ... outer ring, 562 ... rolling element, 57 ... needle roller bearing 570 ... Race, 571 ... Needle roller, 58 ... Spacer, 100 ... Deceleration transmission mechanism, 101 ... 4-wheel drive vehicle, 102 ... Engine, 103 ... Transaxle, 104 ... Front wheel, 105 ... Rear wheel, 106 ... Rear axle shaft , 107: Front axle shaft, 200, 300 ... Reduction transmission mechanism, 500 ... Cylindrical roller bearing, 501 ... Inner ring, 502 ... Outer ring, 503 ... Rolling element, 600 ... Cylindrical roller bearing, 601 ... Inner ring, 602 ... Outer ring, 603 ... rolling elements, O ... rotation _{axis, L, O 1, O 1} ', O 2, O 2' ... _{axis, δ 1, δ 2, δ} ... eccentricity, _{G 1, G} 2 _... operating _{clearance, P} 1, ₂ ... centrifugal force

Claims (8)

A rotating shaft having an eccentric portion that rotates around a first axis and has a second axis that is eccentric from the first axis as a central axis;
A central hole disposed around the rotation axis and having a third axis as a central axis; and a plurality of through holes arranged in parallel at equal intervals around the third axis; and an inner periphery of the central hole An input member comprising an external gear mechanism having a pitch circle with a third axis serving as a central axis, with a bearing interposed between a surface and an outer peripheral surface of the eccentric portion;
The input member is disposed so as to be fitted in the radial direction thereof, meshes with the input member with a number of teeth larger than the number of teeth of the external gear mechanism, and has a pitch circle having a fourth axis as a central axis. A cylindrical housing having a rotation force imparting member made of an internal gear mechanism;
An output member that receives and outputs the rotation force applied to the input member by the rotation force application member of the housing, and includes an output member that is inserted through the plurality of through holes;
When the bearing has an outer ring and an inner ring, and the outer ring is fitted into the center hole and the inner ring is fitted into the eccentric portion with a gap in the radial direction of the rotating shaft, the second axis and the second ring 3 between the outer diameter of the bearing and the center hole in a state where the input member moves on the line orthogonal to the second axis and the fourth axis and abuts against the housing. The diameter difference between the inner diameter of the bearing, the difference in diameter between the inner diameter of the bearing and the outer diameter of the eccentric part, and the radial internal clearance of the bearing is set to be less than half the dimension. There is a deceleration mechanism. The input member has an annular first convex portion having the third axis as a central axis,
2. The speed reduction mechanism according to claim 1, wherein the housing has an annular second convex portion that fits into the first convex portion and has the fourth axis as a central axis. In the input member, a fitting surface of the first convex portion is formed on an outer peripheral surface,
The speed reduction mechanism according to claim 2, wherein the housing has a fitting surface of the second convex portion formed on an inner peripheral surface. In the input member, a fitting surface of the first convex portion is formed on an inner peripheral surface,
The speed reduction mechanism according to claim 2, wherein the housing has a fitting surface of the second convex portion formed on an outer peripheral surface. The input member protrudes in the third axial direction to form the first convex portion,
5. The speed reduction mechanism according to claim 3, wherein the housing protrudes in the fourth axial direction to form the second convex portion. The input member protrudes in a direction perpendicular to the third axis to form the first convex portion,
The speed reduction mechanism according to claim 3, wherein the housing protrudes in a direction perpendicular to the fourth axis and the second convex portion is formed. An electric motor for generating motor rotational force;
A motor rotational force transmission device comprising a deceleration transmission mechanism that decelerates the motor rotational force of the electric motor and transmits the driving force to a driving force transmission target;
The speed reduction transmission mechanism is the speed reduction mechanism according to any one of claims 1 to 6. A motor rotational force transmission device.   The motor rotation force transmission device according to claim 7, wherein the deceleration transmission mechanism transmits the driving force to a differential mechanism as the driving force transmission target.

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