JP2013108538A - Speed reduction mechanism and motor drive force transmission device having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speed reduction mechanism capable of suppressing decrease in a service life of a bearing, and a motor drive force transmission device having the mechanism.SOLUTION: A speed reduction mechanism 5 includes: a motor shaft 42 having an eccentric part 42a; an annular input member 50 comprising an external gear, which is rotatably supported by the eccentric part 42a of the motor shaft 42 via a bearing 54 and has a plurality of pin insertion holes 501b equally spaced around an axial line O; a rotating force imparting member 52 comprising an internal gear, which has a larger number of teeth than that of the input member 50 and meshes with the input member; and a plurality of output members 53, which receive the rotational force imparted by the rotational force imparting member 52 to the input member 50, and output the force power to be inserted into the respective pin insertion holes 501b. The input member 50 includes an outside member 500 made of an iron-based metal having external teeth of the external gear and an inside member 501 made of metal or resin mounted on an inner circumferential surface of the outside member 500, wherein the density of the material of the inside member 501 is smaller than the density of the material of the outside member 500.

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 driving force transmission device including the same.

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

  The electric motor has a motor shaft with an eccentric portion that is rotated by the electric power of the in-vehicle battery, and is disposed on the axis of the deceleration transmission mechanism.

  The deceleration transmission mechanism has a pair of deceleration transmission parts around its axis, is disposed between the electric motor and the differential mechanism (differential case), and is connected to the motor shaft and the differential case. One deceleration transmission unit is coupled to the motor shaft, and the other deceleration transmission unit is coupled to the differential case.

  With the above configuration, the motor shaft of the electric motor is rotated by the power of the on-vehicle battery, and accordingly, the motor driving force is transmitted from the electric motor to the differential mechanism via the speed reduction transmission mechanism, and the left and right wheels are transmitted from this differential mechanism. To be distributed.

  By the way, the deceleration transmission part of this type of motor driving force transmission device includes a revolving member that performs a revolving motion by rotation of a motor shaft of an electric motor, an outer pin that applies a rotating force to the revolving member, and an inner side of the outer pin. It has an inner pin that outputs the rotational force of the revolving member as a rotational force to the differential mechanism.

  The outer pin is attached to the housing of the motor driving force transmission device, and the inner pin is attached to the differential case of the differential mechanism through the revolving member inside the housing.

JP 2007-218407 A

  However, according to the motor driving force transmission device shown in Patent Document 1, since the revolution member (input member) rotates eccentrically, the load on the bearing that rotatably supports the input member increases, and the life of the bearing decreases. Was.

  Accordingly, an object of the present invention is to provide a speed reduction mechanism that can reduce the load on a bearing that supports an input member and thereby suppress a reduction in the life of the bearing, and a motor driving force transmission device including the speed reduction mechanism. .

  In order to achieve the above object, the present invention provides a reduction mechanism (1) to (4) and a motor driving force transmission device including the reduction mechanism.

(1) A rotating shaft having an eccentric portion, and an external gear having a plurality of through holes that are rotatably supported by the eccentric portion of the rotating shaft via a bearing and are arranged at equal intervals around the central axis. An annular input member, a rotation force application member comprising an internal gear meshing with the input member with a number of teeth larger than the number of teeth, and a rotation force applied to the input member by the rotation force application member. A plurality of output members that respectively pass through the plurality of through holes, and the input member includes an iron-based metal outer member provided with external teeth of the external gear, and the outer member. A speed reduction mechanism having an inner member made of metal or resin attached to an inner peripheral surface, wherein the material density of the inner member is smaller than the material density of the outer member.

(2) In the reduction mechanism according to (1), the input member is formed of an aluminum-based metal on the inner member.

(3) In the speed reduction mechanism according to (1) or (2), the input member includes the plurality of through holes.

(4) In the motor driving force transmission device comprising: an electric motor that generates a motor driving force; and a deceleration transmission mechanism that decelerates and transmits the motor driving force of the electric motor to a driving force transmission target. Is the speed reduction mechanism according to any one of (1) to (3) above.

  According to the present invention, it is possible to reduce the load on the bearing that supports the input member and to suppress a reduction in the life of the bearing.

The top view shown in order to demonstrate the outline of the vehicle by which the motor drive force transmission apparatus which concerns on embodiment of this invention is mounted. Sectional drawing shown in order to demonstrate the motor drive force transmission apparatus which concerns on embodiment of this invention. Sectional drawing shown typically in order to demonstrate the deceleration transmission mechanism of the motor drive force transmission apparatus which concerns on embodiment of this invention. The side view shown in order to demonstrate the input member of the motor drive force transmission apparatus which concerns on embodiment of this invention.

[Embodiment]
Hereinafter, a motor driving force transmission device according to an 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 with a drive source as an engine and a rear-wheel-side power system with 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 driving 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 driving force transmission device 1 is configured to transmit a motor driving force of an electric motor 4 (described later) to the pair of rear wheels 105. As a result, the motor driving 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 described later), and the pair of rear wheels 105 are driven. Details of the motor driving 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.

(Overall configuration of motor driving force transmission device 1)
FIG. 2 shows the entire motor driving force transmission device. As shown in FIG. 2, the motor driving force transmission device 1 distributes the motor driving force to the rear wheel 105 (shown in FIG. 1) and the housing 2 with the axis of the rear axle shaft 106 (shown in FIG. 1) as the axis O. The rear differential 3 to be operated, the electric motor 4 for generating a motor driving force for operating the rear differential 3, and the deceleration transmission mechanism 5 for decelerating and transmitting the motor driving force of the electric motor 4 to the rear differential 3 are roughly constituted. Has been.

(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 (the left side in FIG. 1) of the housing 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 23 that protrudes toward the second housing element 21 is integrally provided. The outer peripheral surface of the convex portion 23 is formed as a circumferential surface having an outer diameter smaller than the maximum outer diameter of the first housing element 20 and having the 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 axial line 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 convex portion 27 that protrudes toward the first housing element 20 is integrally provided on one side opening end surface of the second housing element 21 (opening end surface on the first housing element 20 side). The outer peripheral surface of the convex portion 27 is smaller than the maximum outer diameter of the second housing element 21, has an outer diameter substantially the same as the outer diameter of the convex portion 23, and is formed by a circumferential surface having the axis O as the central axis. Has been.

  The third housing element 22 is disposed on the other side of the housing 2 and is entirely formed of 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 28 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 driving 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 transmitted from the rear axle shaft 106 (shown in FIG. 1) to the left and right rear wheels 105 (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 the axis O, and is rotatably supported on the first housing element 20 via a ball bearing 34 and on the motor shaft 42 of the electric motor 4 via a ball bearing 35. The differential case 30 is configured to receive the motor driving force of the electric motor 4 from the deceleration transmission mechanism 5 and rotate around the axis O.

  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 connect the left and right rear axle shafts 106 respectively. 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 mounting holes 300c arranged in parallel at equal intervals around the axis O.

  The pinion gear shaft 31 is disposed on the axis L perpendicular to the axis O in the accommodation space 30 a of the differential case 30, and rotation around the axis L and movement in the axis L direction 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 are housed in the housing space 30a of the differential case 30 and are connected by spline fitting to a rear axle shaft 106 (shown in FIG. 1) that passes through the shaft insertion hole 30b. The pair of side gears 33 are configured to 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 (rotating shaft) 42, and is connected to the rear differential 3 on the axis O via a speed reduction transmission mechanism 5, and the stator 40 is an ECU (Electronic Control Unit: ECU). (Not shown). The electric motor 4 is configured so that the stator 40 receives a control signal from the ECU and generates a motor driving force for operating the differential 3 with the rotor 41 and rotates the rotor 41 together with the motor shaft 42. Has been.

  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 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. The inner peripheral surface is rotatably supported via ball bearings 46, and the whole is formed by a cylindrical shaft member through which the rear axle shaft 106 (shown in FIG. 1) is inserted.

At one end of the motor shaft 42, a planar circular eccentric portion 42a having an axis O ₁ that is eccentric with an axis δ _{1 on} its axis (axis O), and an eccentric amount δ ₂ (δ ₁ == A flat circular eccentric part 42b having an axis O ₂ that is eccentric with δ ₂ = δ) is integrally provided. The one eccentric portion 42a and the other eccentric portion 42b are arranged at positions that are arranged in parallel around the axis O with an equal interval (180 °). That is, the one eccentric portion 42a and the other of the eccentric portion 42b, between the distance and the axis O ₂ from the axis O ₁ to the axis O equal to the distance to the axis O, and the axis O ₁ and the axis O ₂ Are arranged on the outer peripheral surface of the motor shaft 42 so that the distances around the axis O are equal. Further, the eccentric part 42 a and the eccentric part 42 b are arranged at positions parallel to the direction of the 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 input member. As shown in FIGS. 2, 3, and 4, the speed reduction transmission mechanism 5 includes a pair of input members 50, 51, a rotation force applying member 52, and an output member 53, and between the rear differential 3 and the electric motor 4. It is arranged in the middle. The deceleration transmission mechanism 5 is configured to decelerate and transmit the motor driving force of the electric motor 4 to the rear differential 3 as described above.

One input member 50 is formed of an annular external gear having an outer member 500 and an inner member 501, is arranged on the rear differential 3 side of the other input member 51, and is a ball bearing on the eccentric portion 42 a of the motor shaft 42. 54 is rotatably supported via 54. The one input member 50 is configured to receive a motor driving force from the electric motor 4 and perform circular motion (revolution motion around the axis O) in the directions of arrows m ₁ and m ₂ having an eccentricity δ. .

The outer member 500 is disposed on the outer peripheral portion of one input member 50, and is formed of an annular member made of an iron-based metal such as cast iron having a density of 7.0 to 8.8 g / cm ³ , for example. . Thereby, the outer member 500 is hardly deformed, and a dimensional change between two adjacent external teeth is suppressed. As a material of the outer member 500, cast steel or steel may be used instead of cast iron, or other iron-based metal may be used.

The outer member 500, are provided along the circumference (outer circumferential surface) in which a plurality of external teeth 500a with the involute tooth profile is a center axis corresponding to the axis O _1. Number of teeth _{Z 1} of the external teeth 500a is set to, for example, _Z 1 = 195.

The inner member 501 is disposed on the inner peripheral portion of one input member 50 and is attached to the inner peripheral surface of the outer member 500, and the whole is a phenol with cloth having a density of, for example, 1.2 to 1.4 g / cm ^3. It is formed of an annular member made of resin such as resin. As a material for the inner member 501, another resin may be used instead of the phenol resin with cloth.

The inner member 501, the center hole 501a interposing the ball bearings 54 between the axis O ₁ and the center axis, and the eccentric portion 42a of the motor shaft 42 is provided. Moreover, the inner member 501, the pin insertion hole (through hole) 501b of a plurality (six in this embodiment) in parallel at equal intervals in the axial line O ₁ around is provided. The hole diameter of the pin insertion hole 501b is set to be larger than the dimension obtained by adding the outer diameter of the needle roller bearing 55 (described later) to the outer diameter of the output member 53.

  One input member 50 is manufactured by, for example, forming an annular outer member 500 by casting, and forming an annular inner member 501 by processing a commercially available pipe material made of phenol resin with cloth by cutting or the like. After that, the inner member 501 is pressed into the outer member 500.

  Instead of forming the inner member 501 by processing the pipe material made of phenol resin with cloth by cutting or the like, the inner member 501 may be formed using an injection molding technique. Molding materials include polyphenylene sulfide, polyamideimide, polyethylene, polyamide, polyacetal, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyethersulfone, polyetherimide, polyetheretherketone, thermoplastic polyimide, thermosetting polyimide, epoxy Resin or the like is used.

  When these resins are used for the molding material, reinforcing fibers such as glass fibers, carbon fibers, aramid fibers, potassium titanate whiskers and the like may be contained in the resin. The mass of the reinforcing fiber is preferably about 10 to 50% by mass with respect to the mass of the entire inner member 501. Further, the resin may contain additives such as fillers, lubricants and solid lubricants.

The other input member 51 is formed of an annular external gear having an outer member 510 and an inner member 511, is disposed on the electric motor 4 side of the one input member 50, and has a ball bearing on the eccentric portion 42 b of the motor shaft 42. 56 is rotatably supported. The other input member 51 is configured to receive a motor driving force from the electric motor 4 and perform a circular motion (revolution motion around the axis O) in the directions of arrows m ₁ and m ₂ having an eccentricity δ. .

The outer member 510 is disposed on the outer peripheral portion of the other input member 51, and is entirely formed of an annular member made of an iron-based metal such as cast iron having a density of 7.0 to 8.8 g / cm ³ , for example. . Thereby, the outer member 510 is hardly deformed, and a dimensional change between two adjacent external teeth is suppressed. As a material of the outer member 510, cast steel or steel may be used instead of cast iron, or another iron-based metal may be used.

The outer member 510, are provided along the circumference (outer circumferential surface) in which a plurality of external teeth 510a with the involute tooth profile is a center axis corresponding to the axis O _2. Number of teeth _{Z 2} of the external teeth 510a is set to, for example, _Z 2 = 195.

The inner member 511 is disposed on the inner peripheral portion of the other input member 51 and is attached to the inner peripheral surface of the outer member 510, and the whole has a density of, for example, 1.2 to 1.4 g / cm ^3. It is formed of an annular member made of resin such as resin. As a material of the inner member 511, another resin may be used instead of the phenol resin with cloth.

The inner member 511, the center hole 511a interposing the ball bearings 56 between the axis O ₂ as the center axis, and the eccentric portion 42b of the motor shaft 42 is provided. Moreover, the inner member 511, the pin insertion hole (through hole) 511b of a plurality (six in this embodiment) in parallel at equal intervals in the axis O ₂ around is provided. The hole diameter of the pin insertion hole 511b is set to be larger than the dimension obtained by adding the outer diameter of the needle roller bearing 57 (described later) to the outer diameter of the output member 53.

  Since the other input member 51 is manufactured in the same manner as the one input member 50, the description thereof is omitted.

As described above, in the input members 50 and 51, the parts (outer members 500 and 510) that require mechanical strength are made of ferrous metal, and the parts that do not need mechanical strength more than the outer members 500 and 510 ( Each of the inner members 501 and 511) is formed of a resin, thereby reducing the weight as a whole (weight reduction). In this case, in order to reduce the weight of the input members 50 and 51, the boundary between the outer member 500 and the inner member 501 is formed from the center (axis O ₁ ) of the input member 50 and between the outer member 510 and the inner member 511. It is preferable to arrange the boundary at a part as far away as possible from the center (axis O ₂ ) of the input member 51.

The rotation force imparting member 52 is composed of an internal gear having the axis O as the center axis, and is disposed between the first housing element 20 and the second housing element 21, and is entirely disposed in both directions of the axis O. It is formed by a bottomless cylindrical member that opens and constitutes a part of the housing 2. 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. and it is also configured other input member 51 to the arrow l _1, l ₂ direction of rotation force so as to give respectively.

On the inner peripheral surface of the rotation force applying member 52, a first fitting portion 52 a that fits on the outer peripheral surface of the convex portion 23 and a second fitting portion 52 b that fits on the outer peripheral surface of the convex portion 27 are axes. It is provided with a predetermined interval in the direction of O. Further, the external teeth 500a 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. Involute toothed inner teeth 52c that mesh with the outer teeth 510a of 51 are provided. Number of teeth _{Z 3} of the internal teeth 52c is set to, for example, _Z 3 = 208. The reduction ratio α of the deceleration transmission mechanism 5 is calculated from α = (Z ₃ −Z ₂ ) / Z ₂ .

  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, and pin insertion of one input member 50 is performed. The threaded portion 53 a is attached to the pin attachment hole 300 c of the differential case 30 through the hole 501 b and the pin insertion hole 511 b of the other input member 51. The output member 53 is disposed around the axis O at equal intervals through an annular spacer 58 interposed between the head 53 b and the other input member 51. The output member 53 is configured to receive the rotation force applied by the rotation force applying member 52 from the pair of input members 50 and 51 and output the rotation force to the differential case 30 as the rotation force.

  The contact resistance between the outer peripheral surface of the output member 53 and the inner peripheral surface of the pin insertion hole 501b in one input member 50 is reduced at a portion interposed between the screw portion 53a and the head portion 53b. A needle roller bearing 55 for reducing contact resistance with the pin insertion hole 511b in the other input member 51 is also attached.

(Operation of the motor driving force transmission device 1)
Next, the operation of the motor driving force 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 driving force transmission device 1 to drive the electric motor 4, the motor driving force of the electric motor 4 is applied to the deceleration transmission mechanism 5 via the motor shaft 42. 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 rotation force applying member 52 external teeth 500a around (arrow _{n 1} direction shown in FIG. 3), also the input member 51 external teeth 510a 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, the inner peripheral surface of the pin insertion hole 501 b is in the race 550 of the needle roller bearing 55 due to the rotation of the input member 50, and the inner peripheral surface of the pin insertion hole 511 b is in the needle roller bearing 57 due to the rotation of the input member 51. Each abuts against the race 570.

  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 by this rotation movement is rotated from the output member 53 to the differential case 30. Output as power.

  As a result, the differential 3 operates, and the motor driving 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 driving force transmission device 1, centrifugal force acts on the input members 50 and 51 based on the circular motion in accordance with the operation.

  In this case, one input member 50 receives a load due to a centrifugal force generated based on the circular motion, and this load acts on the ball bearing 54 from the one input member 50. However, one input member 50 is made of an iron-based metal. Since the outer member 500 is formed, and the inner member 501 is formed of a material smaller than the density of the material of the outer member 500, the weight of one input member 50 is the case where the entire input member is formed of a ferrous metal. The load acting on the ball bearing 54 is reduced.

  Similarly, the other input member 51 receives a load due to the centrifugal force generated based on the circular motion, and this load acts on the ball bearing 56 from the other input member 51, but the other input member 51 is made of an iron-based metal. Since the outer member 510 is formed, and the inner member 511 is formed of a material smaller than the density of the material of the outer member 510, the weight of the other input member 51 is formed of an iron-based metal as a whole (see FIG. The load acting on the ball bearing 56 is reduced.

  Therefore, in the present embodiment, it is possible to suppress the life reduction of the ball bearing 54 that rotatably supports one input member 50 and the ball bearing 56 that rotatably supports the other input member 51.

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, the input member 50, 51 in the arrow m ₂ Direction Even if it makes a circular motion, the motor rotational force transmission device 1 can be operated in the same manner as in the above embodiment. 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 embodiment]
According to the embodiment described above, the following effects can be obtained.

  Since the weight of the input members 50 and 51 can be reduced, the load acting on the bearings 54 and 56 when the speed reduction transmission mechanism 5 is driven can be reduced, and the life reduction of the ball bearings 54 and 56 can be suppressed.

  As mentioned above, although the deceleration mechanism of this invention and the motor drive force transmission apparatus provided with this were demonstrated based on said embodiment, this invention is not limited to said embodiment, and 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 case where the inner members 501 and 511 of the input members 50 and 51 are made of resin has been described. However, the present invention is not limited to this, and the input member is made of, for example, an aluminum-based metal. The inner member may be formed. Further, as the material of the inner member, other metal having a density lower than that of the material of the outer member may be used instead of the aluminum-based metal. That is, in short, the material of the inner member in the present invention may be a metal or resin having a density lower than that of the material of the outer member.

(2) In the above embodiment, the distance from the axis O ₁ to the axis O is equal to the distance from the axis O ₂ to the axis O, and the distance around the axis O between the axis O ₁ and the axis O ₂ is equal. As described above, the one eccentric portion 42a and the other eccentric portion 42b are arranged on the outer periphery of the motor rotating shaft 42, and the pair of input members 50 are spaced apart from each other at an equal interval (180 °) around the axis O. However, 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. The n input members are disposed at the outer periphery of the motor shaft and at portions spaced around the axis O with an interval of 360 ° / n.

  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 line of two eccentric parts adjacent to each other and the axis line of the motor shaft is 120 °. Three input members are arranged at portions separated by an interval of 120 °.

(3) 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.

(4) In the above embodiment, the ball bearings 54 and 56 which are deep groove ball bearings are used between the inner peripheral surfaces of the center holes 501a and 511a 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 parts 42a and 42b has been described, the present invention is not limited to this, and a ball bearing other than the deep groove ball bearing is used instead of the deep groove ball bearing. Roller bearings may be used. 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. In the present invention, a sliding bearing may be used instead of the rolling bearing.

(5) In the above-described embodiment, the outer peripheral surface of the output member 53 is in contact with the inner peripheral surface of the pin insertion hole 501b of the input member 50 at a portion interposed between the screw portion 53a and the head portion 53b. Although the case where the needle roller bearing 55 which can be contacted and the needle roller bearing 57 which can contact the inner peripheral surface of the pin insertion hole 511b of the input member 51 was each demonstrated was demonstrated, this invention is limited to this. Instead of the needle roller bearing, a roller bearing or ball bearing other than the needle roller bearing may be used. 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. In the present invention, a sliding bearing may be used instead of the rolling bearing.

DESCRIPTION OF SYMBOLS 1 ... Motor drive force transmission apparatus, 2 ... Housing, 20 ... 1st housing element, 20a ... Shaft insertion hole, 21 ... 2nd housing element, 21a ... Inner flange, 22 ... 3rd housing element, 22a ... Shaft Insertion hole, 22b ... cylindrical part, 23 ... convex part, 24 ... seal member, 25 ... annular member, 27 ... convex part, 28 ... seal member, 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, 34, 35 ... ball bearing, 36 ... pin, 4 ... electric motor, 40 ... stator, 41 ... rotor 42 ... Motor shaft, 42a, 42b ... Eccentric part, 43 ... Mounting bolt, 44 ... Ball bearing, 45 ... Sleeve, 4 ... ball bearings, 47 ... resolvers, 470 ... stator, 471 ... rotor, 5 ... deceleration transmission mechanism, 50 ... one input member, 500 ... outer member, 500a ... outer teeth, 501 ... inner member, 501a ... center hole, 501b DESCRIPTION OF SYMBOLS ... Pin insertion hole, 51 ... The other input member, 510 ... Outer member, 510a ... External tooth, 511 ... Inner member, 511a ... Center hole, 511b ... Pin insertion hole, 52 ... Rotation force provision member, 52a ... 1st Fitting part, 52b ... second fitting part, 52c ... inner teeth, 53 ... output member, 53a ... screw part, 53b ... head, 54 ... ball bearing, 55 ... needle roller bearing, 550 ... race, 56 ... Ball bearings, 57 ... Needle roller bearings, 570 ... Races, 58 ... Spacers, 101 ... Four-wheel drive vehicles, 102 ... Engines, 103 ... Transaxles, 104 ... Front wheels, 105 ... Rear wheels, 106 ... Rear axles DOO, 107 ... front axle _{shafts, L, O, O 1,} O 2 ... axis, [delta], [delta] _1, [delta] ₂ ... eccentricity

On the inner peripheral surface of the rotation force applying member 52, a first fitting portion 52 a that fits on the outer peripheral surface of the convex portion 23 and a second fitting portion 52 b that fits on the outer peripheral surface of the convex portion 27 are axes. It is provided with a predetermined interval in the direction of O. Further, the external teeth 500a 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. Involute toothed inner teeth 52c that mesh with the outer teeth 510a of 51 are provided. Number of teeth _{Z 3} of the internal teeth 52c is set to, for example, _Z 3 = 208. The reduction ratio α of the deceleration transmission mechanism 5 is calculated from α = Z ₂ / (Z ₃ −Z ₂ ) .

Claims (4)

A rotating shaft having an eccentric portion;
An annular input member composed of an external gear having a plurality of through holes that are rotatably supported by the eccentric portion of the rotating shaft via a bearing and are arranged at equal intervals around a central axis;
A rotation force application member composed of an internal gear that meshes with the input member with a number of teeth larger than the number of teeth;
Receiving and outputting the rotation force applied to the input member by the rotation force applying member, and comprising a plurality of output members respectively inserted through the plurality of through holes,
The input member includes an iron-based metal outer member provided with external teeth of the external gear, and a metal or resin inner member attached to an inner peripheral surface of the outer member. A speed reduction mechanism in which the material density of the outer member is smaller than the material density of the outer member.   The speed reduction mechanism according to claim 1, wherein the input member is formed of an aluminum-based metal at the inner member.   The speed reduction mechanism according to claim 1 or 2, wherein the input member has the inner member having the plurality of through holes. An electric motor for generating a motor driving force;
In a motor driving force transmission device comprising a deceleration transmission mechanism that decelerates the motor driving force of the electric motor and transmits it to a driving force transmission target
4. The motor driving force transmission device according to claim 1, wherein the deceleration transmission mechanism is a deceleration mechanism according to claim 1.

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