WO2017131141A1

WO2017131141A1 - Transmission device

Info

Publication number: WO2017131141A1
Application number: PCT/JP2017/002898
Authority: WO
Inventors: 翔平坂田
Original assignee: 武蔵精密工業株式会社
Priority date: 2016-01-29
Filing date: 2017-01-27
Publication date: 2017-08-03
Also published as: JP2017133660A

Abstract

Provided is a transmission device provided with a first transmission member of which the center axial line is a first axial line, an eccentric rotation member in which a main shaft part capable of rotating around the first axial line and an eccentric shaft part of which the center axial line is a second axial line are integrally linked, a plate-shaped second transmission member rotatably supported on the eccentric shaft part, a third transmission member of which the center axial line is the first axial line and which faces the second transmission member, a first speed change mechanism between the first and second transmission members, and a second speed change mechanism between the second and third transmission members, wherein second and third transmission grooves (22, 24) provided to both sides of the second transmission member (8) do not overlap each other as seen in a projected plane orthogonal to the second axial line (X2), and one of these transmission grooves is arranged so as to surround the other. It is thereby possible to minimize the decrease in thickness of the second transmission member between the second transmission groove of the first speed change mechanism and the bottom of the third transmission groove of the second speed change mechanism, to avoid strength insufficiency in the second transmission member without setting the thickness of the second transmission member to be especially thick, and to reduce the axial size of the device.

Description

Transmission

The present invention is centered on a transmission device, particularly a first transmission member arranged so that the first axis is a central axis, a main shaft portion rotatable around the first axis, and a second axis eccentric from the first axis. An eccentric rotating member integrally connected to an eccentric shaft portion serving as an axis, a second transmission member supported on the eccentric shaft portion so as to be rotatable about the second axis, and having one side surface facing the first transmission member; A third transmission member disposed so as to have one axis as a central axis and facing the other side surface of the second transmission member; a first transmission mechanism capable of transmitting torque while shifting between the first and second transmission members; The present invention relates to a transmission device including a second transmission mechanism capable of transmitting torque while shifting between the second and third transmission members.

The transmission device is conventionally known as disclosed in, for example, Patent Document 1. In this device, the first speed change mechanism is located on a surface of the first transmission member facing the second transmission member, and the first axis is arranged. A second corrugated annular first transmission groove and a second transmission member on a surface facing the first transmission member, the second transmission member being a corrugated annular centered on the second axis and having a wave number different from the first transmission groove. A plurality of first transmission gears and a plurality of first transmission gears that are interposed at a plurality of intersecting portions of the first and second transmission grooves and perform the transmission between the first and second transmission members while rolling the first and second transmission grooves. A third transmission groove that is on the surface of the second transmission member facing the third transmission member and that is centered on the second axis, and the second transmission mechanism has a first rolling element. A wave-shaped annular member having a wave number different from that of the third transmission groove on the surface of the member facing the second transmission member and centering on the first axis. A plurality of second transmission gears that are interposed at a plurality of intersections of the transmission groove and the third and fourth transmission grooves, and that perform speed change transmission between the second and third transmission members while rolling the third and fourth transmission grooves. 2 rolling elements. And according to the said transmission structure, there exists an advantage which can reduce the axial direction width | variety of the apparatus by reducing the axial direction width | variety of the apparatus by forming a 2nd transmission member in plate shape, for example.

Japanese Patent No. 4814351

However, in the transmission device of Patent Document 1, the second and third transmission grooves formed on both side surfaces of the plate-like second transmission member are the second and third transmission grooves as viewed from the projection plane orthogonal to the second axis. Are arranged so as to overlap each other. Therefore, the thickness of the second transmission member between the bottoms of the second and third transmission grooves inevitably decreases, which is disadvantageous in increasing the strength of the second transmission member.

That is, during transmission of the transmission, each transmission groove in the first and second transmission mechanisms receives a load in the expansion direction from the corresponding rolling element, and stress concentration occurs at the bottom of the groove. At this time, if the thickness of the second transmission member between the two grooves is reduced due to the formation of the second and third transmission grooves, there is a problem that the portion is likely to be deformed and damaged due to the stress concentration. is there.

Therefore, in order to avoid the above problem, the conventional apparatus sets the thickness of the entire second transmission member to be thick in anticipation of the reduction in the thickness, which increases the weight of the second transmission member and thus the weight of the transmission device. Not only does this increase the axial width of the transmission, but also a factor.

The present invention has been made in view of such circumstances, and even if the thickness of the plate-like second transmission member is not set to be particularly thick, the second transmission member is formed on both side surfaces without causing insufficient strength. It is an object of the present invention to provide a transmission device that can form second and third transmission grooves and can effectively suppress an increase in axial width.

In order to achieve the above object, the present invention provides a first transmission member arranged so that the first axis is a central axis, a main shaft portion rotatable around the first axis, and a first shaft eccentric from the first axis. An eccentric rotating member in which an eccentric shaft portion having two axes as a central axis is integrally connected, and a plate that is supported by the eccentric shaft portion so as to be rotatable about a second axis and has one side faced to the first transmission member. A second transmission member having a shape, a third transmission member disposed so as to have the first axis as a central axis, and facing the other side of the second transmission member, and a speed change between the first and second transmission members A first transmission mechanism capable of transmitting torque and a second transmission mechanism capable of transmitting torque while shifting between the second and third transmission members, wherein the first transmission mechanism includes a first transmission member of the first transmission member. , Located on the surface facing the second transmission member and centered on the first axis A second annular transmission having a wave shape different from that of the first transmission groove and having a wave shape centered on the second axis and located on the surface of the second transmission member facing the first transmission member, the first transmission groove having an annular shape. A plurality of first gears that are interposed in a plurality of intersecting portions of the groove and the first and second transmission grooves, and perform transmission transmission between the first and second transmission members while rolling the first and second transmission grooves. The second transmission mechanism is located on a surface of the second transmission member facing the third transmission member and has a wave-shaped annular third transmission groove centered on the second axis; A fourth transmission groove on the surface of the third transmission member facing the second transmission member and having a wave shape centered on the first axis and having a wave number different from that of the third transmission groove; and third and fourth transmissions Shifting between the second and third transmission members while rolling through the third and fourth transmission grooves, which are interposed at a plurality of intersections of the grooves. A plurality of second rolling elements, wherein the second and third transmission grooves do not overlap each other when the transmission grooves are viewed on a projection plane orthogonal to the second axis, The first feature is that one of the transmission grooves is disposed so as to surround the other transmission groove.

Further, in addition to the first feature, the present invention has a second feature that the one transmission groove has a higher wave number than the other transmission groove surrounded by the one transmission groove.

In addition to the first or second feature, the present invention further includes a casing that houses the first to third transmission members and supports the first transmission member so as not to be relatively rotatable. One of the input shaft and the output shaft arranged side by side is connected to the main shaft portion, and the other is connected to the third transmission member.

According to the first feature of the present invention, the second and third transmission grooves formed on both side surfaces of the second transmission member do not overlap each other when the transmission grooves are viewed on the projection plane orthogonal to the second axis. Thus, since the one transmission groove is disposed so as to surround the other transmission groove, the thickness reduction of the second transmission member between the bottoms of the second and third transmission grooves can be minimized. . As a result, even if the thickness of the plate-like second transmission member is not set to a particularly large thickness, the second transmission member can accurately form the second and third transmission grooves on both side surfaces without causing insufficient strength. Therefore, it is possible to contribute to the weight reduction of the second transmission member and thus to the weight reduction of the transmission device, and further, it is possible to contribute to the flat size reduction by suppressing the increase in the axial width of the transmission device.

According to the second feature of the present invention, the one transmission groove has a higher wave number than the other transmission groove surrounded by the one transmission groove, so that the two transmission grooves do not overlap each other when viewed on the projection plane. The arrangement in which one of the transmission grooves surrounds the other transmission groove can be easily and easily performed.

According to the third aspect of the present invention, the casing includes the casing that houses the first to third transmission members and supports the first transmission member so that the first transmission member cannot be relatively rotated, and the input shaft and the output shaft that are aligned on the first axis. Since either one of them is connected to the main shaft portion of the eccentric rotating member and the other one is connected to the third transmission member, the transmission device is compact in the axial direction between the input shaft and the output shaft arranged on the same axis. It can be configured as a speed reducer or speed increaser that can be deployed in the vehicle.

FIG. 1 is a longitudinal sectional view of an essential part showing an example of a power unit for a motorcycle including a transmission (reduction gear) according to a first embodiment of the present invention. (First embodiment) FIG. 2 is an enlarged cross-sectional view of an essential part of the first embodiment (enlarged view taken along the arrow 2 in FIG. 1). (First embodiment) 3 is a cross-sectional view taken along the line 3-3 in FIG. (First embodiment) 4 is a cross-sectional view taken along arrow 4-4 of FIG. (First embodiment) FIG. 5 is an overall longitudinal sectional view of a transmission device (differential device) according to the second embodiment. (Second Embodiment)

C ··· Casing D ··· Differential gear (transmission device)
R ... Reducer (transmission device)
S1 ... 1st transmission shaft (input shaft)
S2 ... 2nd transmission shaft (output shaft)
T1, T2,..., First and second transmission mechanisms X1, X2,..., First and

second axes

5, 8, 9, .., first, second, and third transmission members 6. 6e... Eccentric shaft portion 6j...

Main shaft portions

21, 22,..., First and

second transmission grooves

23, 26 .., first and second balls (first and second rolling elements)
24, 25 ... 3rd and 4th transmission groove

Embodiments of the present invention will be described below with reference to the accompanying drawings.

First embodiment

First, a first embodiment of the present invention shown in FIGS. 1 to 4 will be described. In FIG. 1, a power unit P of a motorcycle includes an electric motor M as a drive source and a speed reducer R as a transmission device that decelerates the driving force and transmits it to the wheels (rear wheels W). The power unit P is mounted on the rear end of a swing arm (not shown) that is pivotally supported on the motorcycle body so as to swing up and down so that it can swing together with the swing arm.

In the power unit P, the speed reducer R decelerates the rotation of the first transmission shaft S1 that also serves as the output shaft of the electric motor M via the first and second transmission mechanisms T1 and T2 and transmits the reduced speed to the second transmission shaft S2. In this case, the rear wheel W is coupled to the second transmission shaft S2 so as to rotate integrally. The first and second transmission shafts S1 and S2 rotate around the first axis X1 through the pair of first and second bearings B1, B1 '; B2, B2' in the unit case Pc of the power unit P, respectively. Supported as possible.

The electric motor M includes a motor case 1, a stator 2 that is fixed to the inner surface of the outer peripheral wall of the case 1, and a rotor 3 that is located inside the stator 2 and is fixed to the first transmission shaft S1. The motor case 1 is divided into two parts, for example, a bottomed cylindrical case body and a lid that closes its open end.

The speed reducer R cooperates with the motor case 1 to form a hollow casing C that constitutes a unit case Pc of the power unit P, and first, second, and second housings that are accommodated in the casing C in an axial state in series. 3 between the

transmission members

5, 8, 9, the eccentric rotation member 6 housed in the casing C and surrounded by the annular first and

second transmission members

5, 8, and the first and

second transmission members

5, 8. The first transmission mechanism T1 capable of transmitting torque while shifting and the second transmission mechanism T2 capable of transmitting torque while shifting between the second and

third transmission members

8 and 9 are main components.

In particular, in the present embodiment, the electric motor M is coupled to the speed reducer R on the same axis (first axis X1), and the casing C and the motor case 1 of the speed reducer R are combined and integrated. The adjacent end portions of each other are fastened by a plurality of bolts 10. In this fastened state, one side wall 1a of the motor case 1 separates the internal spaces of the speed reducer R and the electric motor M, and also functions as one side wall Ca of the casing C of the speed reducer R. The first transmission shaft S1 is rotatably supported on one side wall Ca of the casing C and the other side wall 1b of the motor case 1 via first bearings B1 and B1 ′ (for example, ball bearings).

The first bearing B1 near the speed reducer R has its inner race adjacent to the rotor 3 of the electric motor M with the collar 40 in between, and the first bearing B1, the collar 40 and the rotor 3 are connected to the first transmission shaft. It is clamped and fastened between the intermediate step portion of S1 and the nut 4 screwed to the outer end portion of the shaft S1. An annular seal member 11 is interposed between one side wall Ca of the casing C and the outer periphery of the collar 40. An annular seal member 41 is also interposed between the inner periphery of the collar 40 and the first transmission shaft S1.

The first transmission member 5 is disposed adjacent to the inner surface of the one side wall Ca of the casing C with the first axis X1 as the central axis, and the outer peripheral portion of the first transmission member 5 is splined on the inner peripheral surface of the outer peripheral wall of the casing C. It is fitted SP1. Further, a gap adjusting shim 12 is interposed between the opposing surfaces of the inner surface Ca of the casing C and the outer surface of the first transmission member 5.

The eccentric rotating member 6 integrally includes a main shaft portion 6j having the first axis line X1 as a central axis, and an eccentric shaft portion 6e having a second axis line X2 eccentric from the first axis line X1 by a predetermined eccentric amount e as a central axis line. The first transmission shaft S1 is coaxially connected to the main shaft portion 6j (coupled integrally in the present embodiment). The eccentric shaft portion 6e supports the inner peripheral portion of the annular second transmission member 8 via a third bearing B3 (for example, a ball bearing) so as to be rotatable around the second axis X2. One side surface of the second transmission member 8 faces the inner side surface of the first transmission member 5. Note that the eccentric rotating member 6 and the first transmission shaft S1 may be formed separately and connected so as to rotate together (for example, spline fitting).

The third transmission member 9 is coaxially connected to the second transmission shaft S2 that rotates about the first axis X1. The inner side surface of the third transmission member 9 faces the other side surface of the second transmission member 8.

Thus, the second transmission member 8 rotates about the second axis X2 with respect to the eccentric shaft portion 6e as the eccentric rotation member 6 (first transmission shaft S1) rotates about the first axis X1, while rotating about the second axis X2. Revolve around the first axis X1 with respect to one transmission shaft S1.

By the way, in the present embodiment, the position of the total center of gravity of the eccentric shaft portion 6e of the eccentric rotating member 6 and the second transmission member 8 is unevenly distributed at a position spaced in the direction from the first axis X1 to the second axis X2. Therefore, when the second transmission member 8 revolves while rotating as described above, the centrifugal force of the eccentric rotation system acts in a specific direction (on the offset side of the second axis X2) with respect to the first axis X1. The rotation of the eccentric rotation system is in an unbalanced state, but in order to eliminate or reduce the unbalanced state, a rotation radius that is opposite in phase to the total center of gravity and larger than the rotation radius of the total center of gravity is used. The balance weight 7 is integrally connected to the main shaft portion 6j of the eccentric rotating member 6.

Further, in the present embodiment, the second transmission shaft S2 includes a long shaft body 13 that also serves as an axle, and a cylindrical shaft 14 that is fitted and fixed (for example, welded) to the outer periphery of the inner end portion of the shaft body 13. The outer end portion 13o of the shaft body 13 is a wheel mounting portion having a spline groove on the outer periphery, and a wheel hub Wh of the rear wheel W is detachably coupled to the wheel body Wh by fastening means such as a nut n and the like so as not to be relatively rotatable. Has been.

The second transmission shaft S2 has a first axis line through a pair of second bearings B2 and B2 '(for example, a ball bearing and a roller bearing) on the inner wall of the casing C in the intermediate portion of the shaft body 13 and the cylindrical shaft 14. It is supported rotatably around X1. An annular seal member 15 is interposed between the inner periphery of the casing C and the outer periphery of the shaft body 13 between the second bearings B2 and B2 ′.

Also, the outer periphery of the inner end portion of the cylindrical shaft 14 is spline-fitted SP2 to the inner peripheral surface of a connecting cylindrical portion 9a that protrudes in a cylindrical shape on the outer surface of the third transmission member 9.

Next, the first and second speed change mechanisms T1 and T2 will be described in order.

On the inner surface of the first transmission member 5 facing the second transmission member 8, a wavy annular first transmission groove 21 centering on the first axis X <b> 1 is formed, and the first transmission groove 21 is illustrated in the illustrated example. Then, it extends in the circumferential direction along a hypotrochoid curve having a virtual circle centered on the first axis X1 as a base circle. On the other hand, a corrugated annular second transmission groove 22 centering on the second axis X2 is formed on one side surface of the second transmission member 8 facing the first transmission member 5. In the illustrated example, the second transmission groove 22 extends in the circumferential direction along an epitrochoid curve having a virtual circle centered on the second axis X2 as a base circle, and is different from the wave number Z1 of the first transmission groove 21. Crosses the first transmission groove 21 at a plurality of locations with a wave number Z2 (for example, small). A plurality of first balls 23 as first rolling elements are interposed at intersections (that is, overlapping portions) of the first transmission groove 21 and the second transmission groove 22, and each of the first balls 23 is a first one. And the inner surface of the

2nd transmission grooves

21 and 22 can roll freely.

Between the opposing surfaces of the first transmission member 5 and the second transmission member 8, an annular flat first holding member H1 capable of rotatably holding the plurality of first balls 23 is interposed.

Further, on the other side surface of the second transmission member 8 facing the third transmission member 9, a wavy annular third transmission groove 24 centering on the second axis X2 is formed, and the third transmission groove 24 is In the illustrated example, it extends in the circumferential direction along a hypotrochoidal curve having a virtual circle centered on the second axis X2 as a base circle. On the other hand, on the inner surface of the third transmission member 9 facing the second transmission member 8, a wavy annular fourth transmission groove 25 centering on the first axis X <b> 1 is formed. In the illustrated example, the fourth transmission groove 25 extends in the circumferential direction along an epitrochoidal curve having a virtual circle centered on the first axis X1 as a base circle, and is different from the wave number Z3 of the third transmission groove 24. It intersects with the third transmission groove 24 at a plurality of locations with a wave number Z4 (for example, less). A plurality of second balls 26 as second rolling elements are interposed at the intersecting portion (overlapping portion) of the third transmission groove 24 and the fourth transmission groove 25, and each second ball 26 has a third and a third one. 4 The inner surfaces of the

transmission grooves

24 and 25 can roll freely.

Between the opposing surfaces of the third transmission member 9 and the second transmission member 8, an annular flat second holding member H2 capable of rotatably holding the plurality of second balls 26 is interposed.

By the way, the second and

third transmission grooves

22 and 24 that are formed on both side surfaces of the second transmission member 8 and have a corrugated annular shape are overlapped with each other when the

grooves

22 and 24 are viewed on the projection plane orthogonal to the second axis X2. The first transmission groove (for example, the second transmission groove 22) is arranged so as to surround the other transmission groove (for example, the third transmission groove 24). Moreover, the one transmission groove (for example, the second transmission groove 22) is formed to have a higher wave number than the other transmission groove (for example, the third transmission groove 24) that surrounds the one transmission groove.

Thus, the first transmission groove 21, the second transmission groove 22, and the first ball 23 constitute a first transmission mechanism T1 that cooperates with each other to perform a first-stage speed change (deceleration), and a third transmission. The groove 24, the fourth transmission groove 25, and the second ball 26 constitute a second transmission mechanism T2 that cooperates with each other to perform a second-stage speed change (deceleration).

Next, the operation of the first embodiment will be described.

When the vehicle travels, an on-vehicle electronic control unit controls energization to the electric motor M (and hence rotation of the motor M) based on the driver's accelerator operation. When the first transmission shaft S1 is rotationally driven by the electric motor M, the eccentric shaft portion 6e of the eccentric rotation member 6 integral with the first transmission shaft S1 revolves around the first axis X1, and accordingly, the eccentric shaft portion 6e. The upper second transmission member 8 also revolves around the first axis X1. According to this revolution, both the first transmission groove 21 of the first transmission member 5 and the second transmission groove 22 of the second transmission member 8, both of which are spline-fitted into the casing C and are restricted in rotation, are connected to each other. The first balls 23 engaged at the intersections of the

grooves

21 and 22 roll on the

grooves

21 and 22, so that the second transmission member 8 is rotated about the second axis X2 on the eccentric shaft portion 6 e. Rotate.

According to the rotation and revolution of the second transmission member 8, the intersection of the

grooves

24 and 25 between the third and

fourth transmission grooves

24 and 25 on the second and

third transmission members

8 and 9. As the second balls 26 that engage with each other roll on the

grooves

24 and 25, the third transmission member 9 is driven to rotate about the first axis X1. The rotation driving force is transmitted to the second transmission shaft S2 that is spline-fitted SP2 to the third transmission member 9.

Thus, the rotation of the first transmission shaft S1 driven by the electric motor M is transmitted to the second transmission shaft S2 by decelerating to the second transmission shaft S2 through the first and second transmission mechanisms T1 and T2 in sequence, and thus the second transmission shaft S2. The wheel W can be driven to decelerate by the electric motor M.

In the rolling ball type speed reducer R as in this embodiment, the wave number of the first transmission groove 21 is Z1, the wave number of the second transmission groove 22 is Z2, the wave number of the third transmission groove 24 is Z3, When the wave number of the transmission groove 25 is Z4, the reduction ratio ε between the first transmission shaft S1 (input shaft) and the second transmission shaft S2 (output shaft) is
ε = 1 − {(Z1 × Z3) / (Z2 × Z4)}
Represented as:

In the rolling ball type reduction gear R as in the present embodiment, torque transmission between the first transmission member 5 and the second transmission member 8 is performed by the first transmission groove 21, the plurality of first balls 23, and the second transmission groove. 22, and torque transmission between the second transmission member 8 and the third transmission member 9 is performed via the third transmission groove 24, the plurality of second balls 26, and the fourth transmission groove 25. Thereby, between each of the 1st transmission member 5 and the 2nd transmission member 8, and the 2nd transmission member 8 and the 3rd transmission member 9, torque transmission is carried out to a plurality of places where the 1st and

2nd balls

23 and 26 exist. Since it is performed in a distributed manner, the strength and weight of each transmission element such as the first to

third transmission members

5, 8, 9 and the first and

second balls

23, 26 can be increased. Moreover, according to the transmission structure of the present embodiment, the first to

third transmission members

5, 8, and 9 are each formed in a plate shape and arranged in the axial direction so that the transmission can be easily flattened in the axial direction (reduction gear R). Can be provided.

In the present embodiment, the corrugated annular second and

third transmission grooves

22 and 24 formed on both side surfaces of the second transmission member 8 are projection planes in which both

grooves

22 and 24 are orthogonal to the second axis X2. The second and third transmission grooves are arranged so that one of the transmission grooves (for example, the second transmission groove 22) surrounds the other transmission groove (for example, the third transmission groove 24) without overlapping each other. The thickness reduction of the second transmission member 8 between the

groove bottoms

22 and 24 is minimized. Thus, even if the thickness of the plate-like second transmission member 8 is not set to be particularly thick, the second transmission member 8 has the second and

third transmission grooves

22 and 24 on both side surfaces without causing insufficient strength. Therefore, it is possible to reduce the weight of the second transmission member 8, thereby reducing the transmission device (reduction gear R), and effectively increasing the axial width of the transmission device (reduction gear R). The flatness and miniaturization of the device can be achieved.

Moreover, in the second transmission member 8 of the present embodiment, the one transmission groove (for example, the second transmission groove 22) has a higher wave number than the other transmission groove (for example, the third transmission groove 24) that surrounds the one transmission groove. Thus, the two

transmission grooves

22 and 24 do not overlap each other when viewed on the projection plane, and one of the transmission grooves (for example, the second transmission groove 22) is the other transmission groove (for example, the third transmission groove 24). ) Is increased, and such

non-overlapping transmission grooves

22 and 24 can be easily and easily arranged.

Second embodiment

Next, a second embodiment will be described with reference to FIG. In the previous embodiment, the rolling ball type reduction gear R is exemplified as the transmission device, but the transmission device of the second embodiment is exemplified as the rolling ball type differential device D.

The differential device D is housed in a transmission case 100 together with a transmission (not shown), and a pair of drive axles arranged on the first axis X1 to rotate the ring gear Cg linked to a power source such as an engine via the transmission. Distribution is performed while allowing differential rotation between the drive axles S1 and S2 with respect to S1 and S2 (that is, the first and second transmission shafts). The drive axles S1, S2 and the transmission case 100 are sealed with a seal member 101.

The differential device D includes a casing C that is supported by the mission case 100 so as to be rotatable about the first axis X1, and a differential mechanism Dm described later that is housed in the casing C. The casing C functions as a differential case, and a cylindrical casing main body Cm having a ring gear Cg made of a helical gear on the outer peripheral portion and an outer peripheral end portion integrally joined to both axial end portions of the casing main body Cm. And a pair of left and right first and second side walls Ca and Cb.

Both side walls Ca and Cb integrally have cylindrical boss-like first and second bearings B1 and B2 extending outward in the axial direction at the respective inner peripheral ends. The outer peripheral portions of the first and second bearings B1 and B2 are supported by the transmission case 100 so as to be rotatable around the first axis X1 via an outer bearing 102 (for example, a ball bearing). The first and second drive axles S1 and S2 are rotatably fitted and supported on the inner peripheral surfaces (that is, bearing surfaces) of the first and second bearings B1 and B2, respectively. A spiral groove 121 is provided on the inner peripheral surfaces of the first and second bearings B1 and B2 for pressure-feeding and guiding the lubricating oil in the transmission case 100 into the casing C with relative rotation with the drive axles S1 and S2. , 122 are recessed.

Next, the structure of the differential mechanism Dm will be described. The differential mechanism Dm includes first, second, and

third transmission members

5, 8, and 9 that are accommodated in the axial direction in the casing C, and an annular first and second that are accommodated in the casing C. The eccentric rotating member 6 surrounded by the

transmission members

5, 8, the first transmission mechanism T 1 capable of transmitting torque while shifting between the first and

second transmission members

5, 8, the second and third transmission members 8, The second transmission mechanism T2 capable of transmitting torque while shifting between the nine gears is a main component.

The first transmission member 5 is disposed adjacent to the inner surface of the one side wall Ca of the casing C with the first axis X1 as the central axis, and the outer periphery of the first transmission member 5 is an annular recess of the inner surface of the one side wall Ca of the casing C. Spline fitting SP1 is performed on the inner peripheral surface. Further, a gap adjusting shim 12 is interposed between opposing surfaces of the inner surface Ca of the casing C and the outer surface of the first transmission member 5.

The eccentric rotating member 6 integrally includes a main shaft portion 6j having the first axis line X1 as a central axis, and an eccentric shaft portion 6e having a second axis line X2 eccentric from the first axis line X1 by a predetermined eccentric amount e as a central axis line. The inner end portion of the first drive axle S1 as the first transmission shaft is coaxially connected to the main shaft portion 6j (in the present embodiment, spline fitting 111). A second transmission member 8 is supported on the eccentric shaft portion 6e via a third bearing B3 (for example, a ball bearing) so as to be rotatable about the second axis X2, and one side surface of the second transmission member 8 is 1 It faces the inner surface of the transmission member 5.

The third transmission member 9 is coaxially connected to the second drive axle S2 that rotates about the first axis X1 via the cylindrical shaft 114, and rotates about the first axis X1 together with the second drive axle S2. Further, the inner side surface of the third transmission member 9 faces the other side surface of the second transmission member 8.

The cylindrical shaft 114 is formed in a bottomed cylindrical shape whose inner end is closed, and the closed wall 114b faces the outer surface of the third transmission member 9. Further, the outer periphery of the inner end portion of the cylindrical shaft 114 is spline-fitted SP2 to the inner peripheral surface of the connecting cylindrical portion 9a projecting from the outer surface of the third transmission member 9. Further, the inner peripheral surface of the cylindrical portion 114a of the cylindrical shaft 114 is coaxially connected to the inner end portion of the second drive axle S2 (in this embodiment, spline fitting 112).

Further, between the outer surface of the eccentric rotating member 6 (main shaft portion 6j) and the facing surface of the casing C (first side wall Ca), and between the outer surface of the cylindrical shaft 114 and the facing surface of the casing C (second side wall Cb). A thrust washer is interposed as necessary.

Thus, also in the second embodiment, the second transmission member 8 has the second axis X2 with respect to the eccentric shaft portion 6e as the eccentric rotation member 6 (first drive axle S1) rotates about the first axis X1. Revolving around the first axis X1 relative to the first drive axle S1 while rotating around.

The structure of the first and second speed change mechanisms T1 and T2 of the second embodiment is basically the same as the structure of the first and second speed change mechanisms T1 and T2 of the first embodiment. The description of the mechanism is omitted only by attaching the same reference numerals. However, in the second embodiment, when the first and second speed change mechanisms T1 and T2 rotate the casing C with the eccentric rotating member 6 (first driving axle S1) fixed, the first transmission member 5 is used. The third transmission member 9 is configured to be driven with a double speed increasing ratio.

Therefore, in the second embodiment, the wave number of the first transmission groove 21 is Z1, the wave number of the second transmission groove 22 is Z2, the wave number of the third transmission groove 24 is Z3, and the wave number of the fourth transmission groove 25 is Z4. Then, the first to

fourth transmission grooves

21, 22, 24, and 25 are formed so that the following formula is established.

(Z1 / Z2) × (Z3 / Z4) = 2
Desirably, for example, Z1 = 8, Z2 = 6, Z3 = 6, Z4 = 4, or Z1 = 6, Z2 = 4, Z3 = 8, and Z4 = 6.

For example, in the former case, the eight-wave first transmission groove 21 and the six-wave second transmission groove 22 intersect at seven locations, and seven first balls are formed at the seven intersection portions (overlapping portions). 23, and the six-wave third transmission groove 24 and the four-wave fourth transmission groove 25 intersect at five locations, and five second balls 26 are formed at the five intersections (overlapping portions). Is installed.

In the former case, for example, in a state where the eccentric rotation member 6 (and hence the eccentric shaft portion 6e) is fixed by fixing the first drive axle S1, the ring gear Cg is driven by the power from the engine, and the casing C (and therefore the first shaft). When the first transmission member 5) is rotated about the first axis X1, the first transmission groove 21 of the first transmission member 5 and the second transmission groove 22 of the second transmission member 8 are replaced by the first ball 23. Therefore, the first transmission member 5 drives the second transmission member 8 with a speed increasing ratio of 8/6. Then, according to the rotation of the second transmission member 8, the six-wave third transmission groove 24 of the second transmission member 8 passes the four-wave fourth transmission groove 25 of the third transmission member 9 via the second ball 26. Therefore, the second transmission member 8 drives the third transmission member 9 with a speed increasing ratio of 6/4.

After all, the first transmission member 5 is
(Z1 / Z2) × (Z3 / Z4) = (8/6) × (6/4) = 2
The third transmission member 9 is driven with the speed increasing ratio.

On the other hand, when the differential case (and hence the first transmission member 5) is rotated in a state where the third transmission member 9 is fixed by fixing the second drive axle S2, the rotational drive force of the first transmission member 5 and the second The second transmission member 8 rotates with respect to the eccentric shaft portion 6e (second axis X2) of the eccentric rotating member 6 by the driving reaction force of the transmission member 8 against the stationary third transmission member 9, and the first axis X1. Revolving around, the eccentric shaft portion 6e is driven around the first axis X1. As a result, the first transmission member 5 drives the eccentric rotating member 6 with a double speed increasing ratio.

Thus, when the loads of the eccentric rotating member 6 and the third transmission member 9 are balanced with each other or change with each other, the amount of rotation and the amount of revolution of the second transmission member 8 change steplessly, and the eccentric rotation The average value of the rotational speeds of the member 6 and the third transmission member 9 is equal to the rotational speed of the first transmission member 5. Thus, the rotation of the first transmission member 5 is distributed to the eccentric rotation member 6 and the third transmission member 9, so that the rotational force transmitted from the ring gear Cg to the differential case C can be distributed to the left and right drive axles S1, S2. it can.

Thus, according to the transmission structure of the second embodiment, the first to

third transmission members

5, 8, 9 are each formed in a plate shape and arranged in the axial direction so that the differential device D that can be easily flattened and reduced in the axial direction can be obtained. It can be provided.

Also in this second embodiment, if the arrangement configuration of the second and

third transmission grooves

22 and 24 on both side surfaces of the second transmission member 8 is the same as that of the first embodiment, it is related to the arrangement configuration. Thus, the same effects as the first embodiment can be achieved.

The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

For example, in the first embodiment, as the transmission device, the transmission gear of the vehicle (rear wheel W) implemented on the vehicle speed reducer R for driving the electric motor M to reduce the speed is illustrated, but the transmission device of the present invention is exemplified. May be used for driving wheels of vehicles other than motorcycles, for example, four-wheeled vehicles, or may be used as a speed reducer for various mechanical devices other than vehicles. In any case, the drive source may be an electric motor, an engine or a hydraulic motor, and the drive source case and the transmission casing may be combined and integrated as in the present embodiment. However, it may be configured separately. Further, when used for rear wheel driving of a motorcycle, for example, as in the first embodiment, the drive source (electric motor) is not directly connected to the transmission device (reduction gear R) and is spaced forward from the rear wheel. The drive source may be linked to the transmission device (reduction gear R) via an endless transmission mechanism such as a chain transmission mechanism, a drive shaft mechanism, or the like.

In the first embodiment, the reduction gear R using the first transmission shaft S1 as the input shaft and the second transmission shaft S2 as the output shaft is shown as the transmission device. However, for example, the transmission device may be the first transmission shaft S1. By using the second transmission shaft S2 as the input shaft as the output shaft, the speed increasing device may be used.

In the second embodiment, the differential device D as a transmission device is accommodated in the transmission case 1 of the automobile. However, the differential device D is not limited to the differential apparatus for an automobile, It can be implemented as a differential for a mechanical device.

In the second embodiment, the differential device D is applied to the left / right wheel transmission system to distribute power while allowing differential rotation to the left and right drive axles S1, S2. In the present invention, the differential device may be applied to a front / rear wheel transmission system in a front / rear wheel drive vehicle to distribute power while allowing differential rotation to the front and rear drive wheels. .

Moreover, in the said embodiment, although each

transmission groove

21,22; 24,25 of 1st, 2nd transmission mechanism T1, T2 is made into the corrugated cyclic | annular wave groove along a trochoid curve, these transmission grooves are embodiment. For example, it may be a wave-shaped wave groove along a cycloid curve.

In the above-described embodiment, the first and second ball-shaped first and

second transmission grooves

21 and 22 and the third and

fourth transmission grooves

24 and 25 of the first and second transmission mechanisms T1 and T2 are provided. Although two

rolling elements

23 and 26 are interposed, the rolling elements may be in the form of a roller or a pin. In this case, the first and

second transmission grooves

21 and 22, and the third and fourth The

transmission grooves

24 and 25 are formed in an inner surface shape so that a roller-like or pin-like rolling element can roll.

In the above embodiment, the first and second holding members H1 and H2 that rotatably hold the first and

second balls

23 and 26 are shown. If the first and

second balls

23 and 26 can smoothly roll without H2, the first and second holding members H1 and H2 may be omitted.

In the above embodiment, the first transmission member 5 is formed separately from the casing C, and is connected to the casing C so as not to be relatively rotatable (for example, spline fitting). May be formed integrally with the casing C (for example, one side wall Ca).

Claims

A first transmission member (5) disposed so as to have the first axis (X1) as a central axis;
A main shaft portion (6j) rotatable around the first axis (X1) and an eccentric shaft portion (6e) having a second axis (X2) eccentric from the first axis (X1) as a central axis are integrally connected. An eccentric rotating member (6);
A plate-like second transmission member (8) supported by the eccentric shaft portion (6e) so as to be rotatable about a second axis (X2) and having one side surface facing the first transmission member (5);
A third transmission member (9) disposed so as to have the first axis (X1) as a central axis and facing the other side surface of the second transmission member (8);
A first transmission mechanism (T1) capable of transmitting torque while shifting between the first and second transmission members (5, 8);
A second transmission mechanism (T2) capable of transmitting torque while shifting between the second and third transmission members (8, 9);
The first transmission mechanism (T1) is located on a surface of the first transmission member (5) facing the second transmission member (8) and has a wave-shaped first shape centered on the first axis (X1). A first wave number is transmitted in a wave shape centered on the second axis (X2) on the surface of the transmission groove (21) and the second transmission member (8) facing the first transmission member (5). A second transmission groove (22) different from the groove (21) and a plurality of intersecting portions of the first and second transmission grooves (21, 22) are interposed between the first and second transmission grooves (21, 22). And a plurality of first rolling elements (23) that perform transmission transmission between the first and second transmission members (5, 8) while rolling
The second transmission mechanism (T2) is located on a surface of the second transmission member (8) facing the third transmission member (9) and has a waveform-shaped third centered on the second axis (X2). The wave number of the third transmission is a wave-shaped ring centered on the first axis (X1) on the surface of the transmission groove (24) and the third transmission member (9) facing the second transmission member (8). A fourth transmission groove (25) different from the groove (24) and a plurality of intersecting portions of the third and fourth transmission grooves (24, 25) are interposed between the third and fourth transmission grooves (24, 25). And a plurality of second rolling elements (26) for performing transmission transmission between the second and third transmission members (8, 9) while rolling),
The second and third transmission grooves (22, 24) are not overlapped with each other when the transmission grooves (22, 24) are viewed on the projection plane orthogonal to the second axis (X2). 22) is arranged so as to surround the other transmission groove (24).
The transmission device according to claim 1, characterized in that said one transmission groove (22) has a higher wave number than said other transmission groove (24) which it surrounds.
A casing (C) for housing the first to third transmission members (5, 8, 9) and supporting the first transmission member (5) in a relatively non-rotatable manner;
One of the input shaft (S1) and the output shaft (S2) arranged on the first axis (X1) is the main shaft portion (6j), and either one is the third transmission member (9). The transmission device according to claim 1, wherein the transmission devices are connected to each other.