WO2017086344A1 - Differential device - Google Patents

Differential device Download PDF

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Publication number
WO2017086344A1
WO2017086344A1 PCT/JP2016/083962 JP2016083962W WO2017086344A1 WO 2017086344 A1 WO2017086344 A1 WO 2017086344A1 JP 2016083962 W JP2016083962 W JP 2016083962W WO 2017086344 A1 WO2017086344 A1 WO 2017086344A1
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WO
WIPO (PCT)
Prior art keywords
transmission
axis
side wall
transmission member
differential
Prior art date
Application number
PCT/JP2016/083962
Other languages
French (fr)
Japanese (ja)
Inventor
翔平 坂田
慎弥 松岡
Original Assignee
武蔵精密工業株式会社
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Filing date
Publication date
Application filed by 武蔵精密工業株式会社 filed Critical 武蔵精密工業株式会社
Publication of WO2017086344A1 publication Critical patent/WO2017086344A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H48/00—Differential gearings
    • F16H48/12—Differential gearings without gears having orbital motion
    • F16H48/14—Differential gearings without gears having orbital motion with cams
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H48/00—Differential gearings
    • F16H48/38—Constructional details
    • F16H48/40—Constructional details characterised by features of the rotating cases

Definitions

  • the present invention includes a differential case and a differential mechanism housed in the differential case, and the differential mechanism is capable of distributing rotational torque input to the differential case to a pair of drive shafts supported by the differential case. Relates to the device.
  • a gear mounting flange is connected to the outer periphery of a differential case, and a ring gear is fastened with a bolt to the flange to attach the ring gear to the differential case.
  • a large-diameter ring gear which is a separate and independent part from the differential case, is bolted to the differential case (gear for mounting the gear) by retrofitting, which increases the overall weight of the differential case and the ring gear. This increases the weight of the differential.
  • the present invention has been proposed in view of the above, and an object of the present invention is to provide a differential device that can suppress an increase in the weight of the differential case due to the ring gear and can also increase the rigidity and strength of the differential case.
  • the present invention comprises a differential case and a differential mechanism housed in the differential case, and the differential mechanism supports a pair of rotational torques input to the differential case.
  • a differential device that can be distributed to a drive shaft, wherein the differential case has a ring gear composed of a helical gear that receives the rotational torque, and a boss portion that supports the pair of drive shafts at an inner peripheral end portion and an outer peripheral end portion.
  • the thickness of the first portion of each side wall plate portion from the predetermined intermediate portion close to the ring gear in the radial direction to the outer peripheral end portion gradually increases as it approaches the outer peripheral end portion, and the first portion of each side wall plate portion
  • the inner surface, the first characterized in that it curved axially inwardly towards the ring gear.
  • the thickness of the second portion of each side wall plate portion from the predetermined intermediate portion to the boss portion gradually increases as the boss portion approaches. It is characterized by.
  • the present invention has a third feature in that a step is formed on the joint surface between the outer peripheral end of each side wall plate and the ring gear.
  • the present invention provides a first transmission integrally provided on one of the side wall plate portions with a first axis passing through the centers of the two boss portions as a central axis.
  • a member, a main shaft portion connected to one of the drive shafts and rotatable about the first axis, and an eccentric shaft portion having a second axis eccentric from the first axis as a central axis are integrally coupled to each other.
  • a third transmission member that is rotatable about the first axis, a first transmission mechanism that is capable of transmitting torque while shifting between the first and second transmission members, and a transmission between the second and third transmission members.
  • a second speed change mechanism capable of transmitting torque
  • the first speed change mechanism is a first transmission member of the first transmission member, which is on the surface facing the second transmission member and has a wavy annular shape around the first axis, and the second transmission member.
  • a second annular groove having a wave shape centered on the second axis and having a wave number different from that of the first transmission groove, and a plurality of intersections of the first and second transmission grooves
  • a plurality of first rolling elements that perform transmission transmission between the first and second transmission members while rolling along the first and second transmission grooves, and the second transmission mechanism includes a second transmission member, The third transmission groove on the surface facing the three transmission members and centered on the second axis, and the third transmission member on the surface facing the second transmission member and centered on the first axis
  • a fourth transmission groove having a wave shape and a wave number different from that of the third transmission groove, and a plurality of intersections of the third and fourth transmission grooves, and the third and fourth transmission grooves.
  • a plurality of second rolling elements that perform transmission transmission between the second and third transmission members while rolling, wherein the wave number of the first transmission groove is Z1, the wave number of the second transmission groove is Z2, and the second When the wave number of the third transmission groove is Z3 and the wave number of the fourth transmission groove is Z4,
  • the following formula (Z1 / Z2) ⁇ (Z3 / Z4) 2
  • the fourth feature is that is established.
  • the differential case has a ring gear that receives rotational torque, and a boss portion that supports a pair of drive shafts at the inner peripheral end portion, and the outer peripheral end portions at both axial end portions of the ring gear.
  • the ring gear includes a pair of side wall plates that are joined to each other, the ring gear constitutes a part of the differential case (outer peripheral wall), and thus the weight of the differential case can be reduced, contributing to the weight reduction of the differential device. Can do.
  • the both side wall plate portions of the differential case are formed so that the axial distance between the outer side surfaces of the differential case becomes longer inward in the radial direction, that is, toward the boss portion.
  • one side portion of the rotation axis (one side portion of both side wall plate portions and ring gear) is formed in a hem-like mountain shape, which can effectively increase the falling rigidity of the differential case,
  • the ring gear is a helical gear that receives a thrust load through the gear meshing portion as in the present invention, it is possible to effectively suppress the axial collapse of the differential case against the thrust load. Improvement is achieved.
  • each side wall plate portion is formed so as to gradually increase the thickness of the first portion from the predetermined intermediate portion close to the ring gear in the radial direction to the outer peripheral end portion of each side wall plate portion as it approaches the outer peripheral end portion, Since the inner surface of the first portion of the side wall plate portion bends inward in the axial direction toward the ring gear, the first portion near the outer peripheral end can efficiently receive the thrust load, and each side wall plate The differential case's falling rigidity can be efficiently enhanced while minimizing the increase in the weight of the part, and the joint surface (that is, the fitting allowance) between the outer peripheral end of each side wall plate (first part) and the ring gear is axial. Therefore, the coupling strength between the side wall plate portions and the ring gear can be effectively increased.
  • each side wall plate portion gradually increases the thickness of the second portion of each side wall plate portion from the predetermined intermediate portion to the boss portion as it approaches the boss portion.
  • the thrust load can be efficiently received also in the second portion near the boss portion, and the falling rigidity of the differential case can be further efficiently enhanced while suppressing the increase in the weight of each side wall plate portion as much as possible.
  • the boss portion can be connected to the thick inner peripheral end portion of each side wall plate portion (second portion), the bonding strength between each side wall plate portion and the boss portion can be effectively increased.
  • a plurality of intervening first and second transmission grooves having different wave numbers are interposed between the first and second transmission members of the differential mechanism. Torque is transmitted via the first rolling element (that is, distributed in a plurality of locations in the circumferential direction), and the wave-shaped third and fourth transmission grooves having different wave numbers between the second and third transmission members. Torque is transmitted via a plurality of second rolling elements interposed at a plurality of intersections (that is, distributed in a plurality of locations in the circumferential direction), so that the load burden on each transmission element is reduced and strength is increased. Increase and weight reduction are achieved.
  • the differential mechanism can be configured to be flat in the axial direction, it can contribute to the flattening of the differential case, and hence the differential device. In this way, since the collapsed rigidity is high, sufficient practical strength can be secured without difficulty.
  • FIG. 1 is a longitudinal front view of a differential according to an embodiment of the present invention.
  • FIG. 2 is an exploded perspective view of a main part (differential mechanism) of the differential device.
  • FIG. 3 is a cross-sectional view taken along arrow 3-3 in FIG.
  • First embodiment 4 is a cross-sectional view taken along arrow 4-4 of FIG.
  • FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. (First embodiment)
  • FIGS. 1 to 5 First, an embodiment of the present invention shown in FIGS. 1 to 5 will be described.
  • a differential device D as a transmission device is housed in a transmission case 1 of an automobile together with a transmission.
  • the left and right drive axles S1, S2 (in which the rotation of the ring gear Cg that rotates in conjunction with the output side of the transmission is aligned on the central axis of the differential device D, that is, the first axis X1, are relatively rotatable. That is, with respect to the drive shaft), the drive shafts S1 and S2 are distributed while allowing differential rotation between them.
  • the drive axles S1, S2 and the transmission case 1 are sealed with seal members 4, 4 '.
  • the differential device D includes a differential case C that is supported by the mission case 1 so as to be rotatable about the first axis X1, and a differential mechanism 3 described later that is accommodated in the differential case C.
  • the differential case C includes a ring gear Cg made of a helical gear having oblique teeth Cga provided on the outer periphery of a short cylindrical gear body, and a pair of left and right first and first pairs whose outer peripheral ends are joined to both axial ends of the ring gear Cg.
  • Two side wall plate portions Ca and Cb are provided.
  • the both side wall plate portions Ca and Cb integrally have a boss portion B at each inner peripheral end, and the outer peripheral portion of the boss portion B is connected to the transmission case 1 via bearings 2 and 2 '. It is supported so as to be rotatable about one axis X1. Further, first and second drive axles S1 and S2 having the first axis X1 as a rotation axis are rotatably fitted and supported on the inner peripheral portion of the boss portion B, respectively.
  • the first and second side wall plate portions Ca and Cb of the differential case C have an axial distance between their outer surfaces (that is, an axial width of the differential case C) directed radially inward. It is formed so as to become longer (that is, closer to the boss B). Moreover, each of the side wall plate portions Ca and Cb is formed so as to gradually increase the thickness of the first portion a1 from the predetermined intermediate portion m near the ring gear Cg in the radial direction to the outer peripheral end portion as it approaches the outer peripheral end portion. Is done.
  • the inner side surfaces of the first portions a1 of the side wall plate portions Ca and Cb are bent inward in the axial direction toward the ring gear Cg. Further, the side wall plate portions Ca and Cb are formed so as to gradually increase the thickness of the second portion a2 from the predetermined intermediate portion m to the boss portion B as they approach the boss portion B.
  • the joint surfaces between the outer peripheral ends of the first and second side wall plate portions Ca and Cb and the ring gear Cg are integrally joined by appropriate joining means such as welding, adhesion, and caulking. Further, a step s is formed on the joint surface, and the step s effectively enhances the axial positioning accuracy and the coupling strength between the outer peripheral end portions of the side wall plate portions Ca and Cb and the ring gear Cg. It is done.
  • the ring gear Cg constitutes a part (outer peripheral wall portion) of the differential case C, so that the weight reduction of the differential case C and thus the differential device D is achieved. Is done.
  • the first and second side wall plate portions Ca and Cb of the differential case are formed such that the axial distance between the outer side surfaces of the differential case becomes longer inward in the radial direction, the longitudinal section of the differential case C As shown in FIG. 1, the differential case C is formed in a mountain shape in which one side of the differential axis C with respect to the first axis X ⁇ b> 1 is widened, thereby effectively increasing the falling rigidity of the differential case C.
  • each of the side wall plate portions Ca and Cb is formed so as to gradually increase the thickness of the first portion a1 near the ring gear Cg as it approaches the outer peripheral end portion (that is, in a flared shape), and the first portion. Since the inner side surface of a1 bends inward in the axial direction toward the ring gear Cg, the thrust load is efficiently received by the first portion a1 near the outer peripheral end, and therefore the weight of each side wall plate portion Ca, Cb increases.
  • the fall rigidity of the differential case C can be efficiently reinforced while suppressing as much as possible.
  • the joint surface (that is, the fitting allowance) between the outer peripheral end of the first portion a1 and the ring gear Cg can be secured as much as possible in the axial direction, the coupling strength between the side wall plate portions Ca and Cb and the ring gear Cg is high. Effectively enhanced.
  • each side wall plate portion Ca, Cb gradually increases the thickness of the second portion a2 near the boss portion B as it approaches the boss portion B, so that the thrust load is also efficiently received at the second portion a2. It can be transmitted to the part B side, and the falling rigidity of the differential case C can be more efficiently enhanced while suppressing the increase in weight of the side wall plate parts Ca and Cb as much as possible. Moreover, since the boss portion B can be connected to the thick inner peripheral end portion of the second portion a2, the coupling strength between the side wall plate portions Ca and Cb and the boss portion B is effectively enhanced.
  • the differential mechanism 3 includes a first transmission member 5 provided integrally with the first side wall plate portion Ca (specifically, the thick second portion a2) and rotatable around the first axis X1, A main shaft portion 6j that is spline-fitted 16 to the first drive axle S1 and is rotatable about the first axis X1, and an eccentric shaft portion 6e that is centered on a second axis X2 that is eccentric from the first axis X1 by a predetermined amount e.
  • An eccentric rotating member 6 integrally connected to each other, and an annular second transmission whose one side is opposed to the first transmission member 5 and rotatably supported by the eccentric shaft portion 6e via a bearing 7.
  • An annular third transmission member 9 that is disposed opposite to the other side of the member 8 and the second transmission member 8 and is spline-fitted 17 to the second drive axle S2 and rotatable about the first axis X1;
  • a first transmission mechanism capable of transmitting torque while shifting between the first and second transmission members 5 and 8. 1, and a second transmission mechanism T2 which transmit the torque while shifting between the second and third transmission members 8,9.
  • the second transmission member 8 is fitted to and supported by the eccentric shaft portion 6e of the eccentric rotating member 6 having the main shaft portion 6j rotatably supported about the first axis X1 so as to be rotatable about the second axis X2.
  • the second transmission member 8 rotates around the first axis X1 of the eccentric rotation member 6 and rotates around the second axis X2 with respect to the eccentric shaft portion 6e, while rotating to the main shaft portion 6j.
  • it can revolve around the first axis X1.
  • the second transmission member 8 includes an annular first half 8a that is rotatably supported by the eccentric shaft portion 6e of the eccentric rotating member 6 via a bearing 7, and a balance weight described later on the first half 8a.
  • the first transmission mechanism T1 is provided between the first half body 8a and the first transmission member 5
  • the second transmission mechanism T2 is provided between the second half body 8b and the third transmission member 9. are provided respectively.
  • the third transmission member 9 is spline-fitted 17 to the second drive axle S2 and is connected coaxially to the main shaft portion 6j rotatable around the first axis X1 and the inner end portion of the main shaft portion 6j.
  • the disc portion 9c is combined and integrated.
  • a thrust washer 15 is interposed between the inner side surface of the second side wall plate portion Cb and the third transmission member 9 (the back surface of the disc portion 9c) so as to be relatively rotatable.
  • the differential mechanism 3 is opposite in phase to the eccentric shaft portion 6e of the eccentric rotating member 6 and the total center of gravity G of the second transmission member 8 across the first axis X1, and larger than the rotational radius of the total center of gravity G.
  • a balance weight W attached to the main shaft portion 6j of the eccentric rotating member 6.
  • This balance weight W is comprised from the cyclic
  • the internal space of the second transmission member 8 (the connecting member 8c) is an accommodation space SP for accommodating the balance weight W.
  • the main shaft portion 6j of the eccentric rotating member 6 has an inner end portion extending into the accommodation space SP, and a balance weight W is attached to the outer periphery of the extended end portion 6ja.
  • the mounting base portion Wm is fitted to the outer periphery of the extended end portion 6ja of the main shaft portion 6j, and the anti-rotation that allows axial sliding between the fitting surfaces but restricts relative rotation.
  • a flat engagement surface 14 is provided.
  • the balance weight W is fixed to the main shaft portion 6j by attaching or detaching a retaining ring 10 such as a circlip as a retaining member that prevents the attachment base portion Wm from being detached from the main shaft portion 6j to the extension end portion 6ja of the main shaft portion 6j. It is done by wearing it as possible.
  • a locking groove that can elastically lock the retaining ring 10 is formed in the outer periphery of the extended end portion 6ja of the main shaft portion 6j.
  • the inner surface of the first transmission member 5 facing the one side surface (that is, the first half 8a) of the second transmission member 8 has a waveform centered on the first axis X1.
  • An annular first transmission groove 21 is formed, and the first transmission groove 21 extends in the circumferential direction along a hypotrochoid curve having a virtual circle centered on the first axis X1 in the illustrated example.
  • a corrugated annular second transmission groove 22 centering on the second axis X2 is formed on one side surface (first half 8a) of the second transmission member 8 facing the first transmission member 5.
  • 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 smaller than the wave number of the first transmission groove 21. It has a wave number and intersects the first transmission groove 21 at a plurality of locations.
  • a plurality of first transmission balls 23 as first rolling elements are interposed at intersections (that is, overlapping portions) of the first transmission grooves 21 and the second transmission grooves 22, and each of the first transmission balls 23. Can roll on the inner surfaces of the first and second transmission grooves 21 and 22.
  • annular flat first holding member H1 is interposed between the opposing surfaces of the first transmission member 5 and the second transmission member 8 (first half 8a).
  • the first holding member H1 can maintain the engaged state of the plurality of first transmission balls 23 in both the transmission grooves 21 and 22 at the intersections of the first and second transmission grooves 21 and 22.
  • the plurality of first rolling balls 23 are provided with a plurality of circular holding holes 31 for holding the plurality of first rolling balls 23 in a freely rotating manner while keeping their mutual spacing constant.
  • each 1st transmission ball 23 passes through each curvature sudden change part of each of the 1st, 2nd transmission grooves 21 and 22, the turbulence in a groove is controlled effectively, the curvature Rolling can be performed smoothly even in sudden changes, and transmission efficiency is improved.
  • a corrugated annular third transmission groove 24 centering on the second axis X ⁇ b> 2 is formed on the other side surface of the second transmission member 8 (that is, the second half 8 b).
  • the third transmission groove 24 extends in the circumferential direction along a hypotrochoidal curve having a virtual circle centered on the second axis X2 as a base circle.
  • a corrugated annular fourth transmission groove 25 centering on the first axis X1 is formed on the surface of the third transmission member 9 facing the second transmission member 8, that is, on the inner side surface of the disc portion 9c.
  • 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 smaller than the wave number of the third transmission groove 24. It has a wave number and intersects with the third transmission groove 24 at a plurality of locations.
  • a plurality of second transmission balls 26 as second rolling elements are interposed at intersections (overlapping portions) of the third transmission groove 24 and the fourth transmission groove 25, and each second transmission ball 26 is The inner side surfaces of the third and fourth transmission grooves 24 and 25 can roll freely.
  • annular flat second holding member H2 is interposed between the opposing surfaces of the third transmission member 9 and the second transmission member 8 (second half 8b).
  • the second holding member H2 can maintain the engagement state of the plurality of second transmission balls 26 with the transmission grooves 24 and 25 at the intersections of the third and fourth transmission grooves 24 and 25.
  • the plurality of second rolling balls 26 are provided with a plurality of circular holding holes 32 for holding the plurality of second rolling balls 26 so as to be rotatable while restricting their mutual intervals to be constant.
  • each second transmission ball 26 is effectively prevented from violating in the groove even when passing through the suddenly changing portions of the third and fourth transmission grooves 24 and 25, so that the curvature thereof is reduced. Rolling can be performed smoothly even in sudden changes, and transmission efficiency is improved.
  • 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
  • the wave number of the fourth transmission groove 25 is Z4, the following equation is established.
  • the eight-wave first transmission groove 21 and the six-wave second transmission groove 22 intersect at seven locations, and seven first transmission balls 23 at the seven intersection portions (overlapping portions).
  • the six-wave third transmission groove 24 and the four-wave fourth transmission groove 25 intersect at five locations, and five second transmission balls 26 at the five intersections (overlapping portions). Is installed.
  • first transmission groove 21, the second transmission groove 22, and the first transmission ball 23 cooperate with each other and can transmit torque while shifting between the first transmission member 5 and the second transmission member 8.
  • the transmission mechanism T1 is configured, and the third transmission groove 24, the fourth transmission groove 25, and the second transmission ball 26 cooperate with each other to transmit torque while shifting between the second transmission member 8 and the third transmission member 9.
  • a possible second speed change mechanism T2 is configured.
  • the ring gear Cg is driven by the power from the engine, and the differential case C and therefore the first
  • the first transmission groove 21 of the first transmission member 5 is replaced with the second transmission groove 22 of the sixth transmission wave of the second transmission member 8 and the first transmission ball 23. Therefore, the first transmission member 5 drives the second transmission member 8 with a speed increasing ratio of 8/6.
  • the six-wave third transmission groove 24 of the second transmission member 8 replaces the four-wave fourth transmission groove 25 of the disk portion 9 c of the third transmission member 9. Since the second transmission ball 26 is driven through the second transmission ball 26, the second transmission member 8 drives the third transmission member 9 with a speed increasing ratio of 6/4.
  • the third transmission member 9 is driven with the speed increasing ratio.
  • the differential case C (and hence the first transmission member 5) is rotated in a state in which the third transmission member 9 is fixed by fixing the left second drive axle S2, the rotational driving force of the first transmission member 5 is rotated.
  • the second transmission member 8 rotates with respect to the eccentric shaft portion 6e (second axis X2) of the eccentric rotation member 6 by the driving reaction force of the second transmission member 8 against the stationary third transmission member 9. Revolving around the first axis X1, the eccentric shaft portion 6e is driven around the first axis X1.
  • the first transmission member 5 drives the eccentric rotating member 6 with a double speed increasing ratio.
  • 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.
  • 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.
  • the rotational torque of the first transmission member 5 is applied to the second transmission member 8 via the first transmission groove 21, the plurality of first transmission balls 23 and the second transmission groove 22, and also to the second transmission member 8.
  • the rotational torque of the second transmission member 8 is transmitted to the third transmission member 9 through the third transmission groove 24, the plurality of second transmission balls 26, and the fourth transmission groove 25, respectively.
  • torque transmission is performed in a distributed manner at a plurality of locations where the first and second transmission balls 23 and 26 exist.
  • the strength and weight of each transmission element such as the first to third transmission members 5, 8, 9 and the first and second transmission balls 23, 26 can be increased.
  • the power input from the power source to the differential case C (first transmission member 5) is transmitted via the second transmission member 8 and the first and second transmission mechanisms T1 and T2.
  • the eccentric rotation member 6 and the third transmission member 9 are distributed while allowing differential rotation.
  • the present invention is applicable to various differential devices other than the embodiment, such as pinions (differential gears). ) And a pair of side gears meshed therewith, it may be applied to a conventionally known gear-type differential device.
  • the differential gear D is accommodated in the mission case M of a motor vehicle
  • the differential gear of this invention is not limited to the differential gear for motor vehicles, Various mechanical devices It can be implemented as a differential device.
  • 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.
  • the differential device may be applied to a front / rear wheel transmission system in a front / rear wheel drive vehicle to distribute power to the front / rear drive wheels while allowing differential rotation.
  • the 2nd transmission member 8 of the said embodiment was comprised from the 1st, 2nd half bodies 8a and 8b and the connection member 8c, the 2nd transmission member 8 is the 1st on one surface of a single member.
  • the two transmission grooves 22 may be provided with the third transmission groove 24 on the other surface.
  • the first and second transmission mechanisms T1 and T2 are each a rolling ball type transmission mechanism.
  • the speed change mechanism is not limited to the structure of the above embodiment. That is, various speed change mechanisms including at least an eccentric rotating member and a second transmission member capable of rotating around the second axis and revolving around the first axis in conjunction with the rotation thereof, such as an inscribed planetary gear mechanism
  • a cycloid reduction gear (speed increaser) or a trochoid reduction gear (speed increase) having various structures may be applied to at least one of the first and second transmission mechanisms of the present invention.
  • the balance weight W is stored in the internal space SP of the second transmission member 8.
  • the location of the balance weight W is not limited to the embodiment, and for example, the second transmission member. You may arrange
  • each transmission groove 21,22; 24,25 of 1st, 2nd transmission mechanism T1, T2 is made into the corrugated cyclic
  • these transmission grooves are embodiment.
  • it may be a wave-shaped wave groove along a cycloid curve.
  • 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.
  • the rolling elements 23 and 26 may be in the form of a roller or a pin.
  • 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.
  • the eccentric rotating member 6 and the third transmission member 9 are connected to the drive axles S1 and S2 supported by the differential case C (spline fitting), and the differential case C is connected via the drive axles S1 and S2.
  • the eccentric rotating member 6 and the third transmission member 9 may be directly supported by the differential case C.
  • the first and second holding members H1 and H2 are used to smoothly roll the first and second rolling balls 23 and 26. If the first and second rolling balls 23 and 26 can smoothly roll without the members H1 and H2, the first and second holding members H1 and H2 may be omitted.

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Abstract

Provided is a differential device in which power is inputted to a differential case through a helical ring gear, wherein: the differential case (C) is provided with a ring gear (Cg), and a pair of side wall plates (Ca, Cb) that have a boss (B) on the inner peripheral end and that are joined at the outer peripheral end to both axial ends of the ring gear (Cg); the axial distance between the outer lateral surfaces of the side wall plates (Ca, Cb) increases diametrically inward; the thicknesses of the first portions (a1) of the side wall plates (Ca, Cb), which extend to the outer peripheral ends from predetermined middle parts (m) diametrically near the ring gear (Cg), gradually increase towards the outer peripheral ends; and the inner-side surfaces of the first portions (a1) of the side wall plates (Ca, Cb) curve axially inward towards the ring gear (Cg). An increase in the weight of the differential case due to the ring gear can thereby be suppressed, and the rigidity and strength of the differential case can be increased.

Description

差動装置Differential
　本発明は、デフケースと、このデフケース内に収容された差動機構とを備え、その差動機構が、デフケースに入力される回転トルクを、デフケースに支持した一対のドライブ軸に分配可能な差動装置に関する。 The present invention includes a differential case and a differential mechanism housed in the differential case, and the differential mechanism is capable of distributing rotational torque input to the differential case to a pair of drive shafts supported by the differential case. Relates to the device.
　上記差動装置としては、例えば特許文献１に示されるようにデフケースの外周部にギヤ取付用フランジを連設し、このフランジにリングギヤをボルトで締結することでデフケースにリングギヤを取付けるようにしたものがよく知られている。 As the differential device, for example, as shown in Patent Document 1, a gear mounting flange is connected to the outer periphery of a differential case, and a ring gear is fastened with a bolt to the flange to attach the ring gear to the differential case. Is well known.
日本特開２０１３－７２５２４号公報Japanese Unexamined Patent Publication No. 2013-72524
　ところがこのような従来装置では、デフケースとは別個独立の部品とした大径のリングギヤをデフケース（ギヤ取付用フランジ）に後付けでボルト結合するため、そのデフケース及びリングギヤの全体重量が増え、延いては差動装置の重量増大を招いている。 However, in such a conventional device, a large-diameter ring gear, which is a separate and independent part from the differential case, is bolted to the differential case (gear for mounting the gear) by retrofitting, which increases the overall weight of the differential case and the ring gear. This increases the weight of the differential.
　本発明は、上記に鑑み提案されたものであり、リングギヤに因るデフケースの重量増加を抑制し、併せてデフケースの剛性強度アップも図ることができる差動装置を提供することを目的とする。 The present invention has been proposed in view of the above, and an object of the present invention is to provide a differential device that can suppress an increase in the weight of the differential case due to the ring gear and can also increase the rigidity and strength of the differential case.
　上記目的を達成するために、本発明は、デフケースと、このデフケース内に収容された差動機構とを備え、その差動機構が、デフケースに入力される回転トルクを、デフケースに支持した一対のドライブ軸に分配可能な差動装置であって、前記デフケースは、前記回転トルクを受けるヘリカルギヤよりなるリングギヤと、前記一対のドライブ軸を支持するボス部を内周端部に有し且つ外周端部が前記リングギヤの軸方向両端部にそれぞれ接合される一対の側壁板部とを備え、前記両側壁板部は、その両者の外側面間の軸方向距離が径方向内方に向かうにつれて長くなると共に、各側壁板部の、径方向でリングギヤ寄りの所定中間部から前記外周端部までの第１部分の肉厚が外周端部に近づくにつれて漸増し、前記各側壁板部の前記第１部分の内側面が、前記リングギヤに向かって軸方向内方側に彎曲していることを第１の特徴とする。 In order to achieve the above object, the present invention comprises a differential case and a differential mechanism housed in the differential case, and the differential mechanism supports a pair of rotational torques input to the differential case. A differential device that can be distributed to a drive shaft, wherein the differential case has a ring gear composed of a helical gear that receives the rotational torque, and a boss portion that supports the pair of drive shafts at an inner peripheral end portion and an outer peripheral end portion. And a pair of side wall plate portions respectively joined to both end portions in the axial direction of the ring gear, and the both side wall plate portions become longer as the axial distance between the outer side surfaces of the ring gears becomes radially inward. The thickness of the first portion of each side wall plate portion from the predetermined intermediate portion close to the ring gear in the radial direction to the outer peripheral end portion gradually increases as it approaches the outer peripheral end portion, and the first portion of each side wall plate portion The inner surface, the first characterized in that it curved axially inwardly towards the ring gear.
　また本発明は、第１の特徴に加えて、前記各側壁板部の、前記所定中間部から前記ボス部までの第２部分の肉厚がボス部に近づくにつれて漸増していることを第２の特徴とする。 According to the second aspect of the present invention, in addition to the first feature, the thickness of the second portion of each side wall plate portion from the predetermined intermediate portion to the boss portion gradually increases as the boss portion approaches. It is characterized by.
　また本発明は、前記第１又は第２の特徴に加えて、前記各側壁板部の外周端部と前記リングギヤとの相互の接合面には段差を有することを第３の特徴とする。 Further, in addition to the first or second feature, the present invention has a third feature in that a step is formed on the joint surface between the outer peripheral end of each side wall plate and the ring gear.
　また本発明は、前記第１～第３の何れかの特徴に加えて、前記両ボス部の中心を通る第１軸線を中心軸線として一方の前記側壁板部に一体に設けられた第１伝動部材と、一方の前記ドライブ軸に接続されて前記第１軸線回りに回転可能な主軸部、および前記第１軸線から偏心した第２軸線を中心軸線とする偏心軸部が互いに一体に連結された偏心回転部材と、前記第１伝動部材に対向配置されて前記偏心軸部に回転自在に支持される第２伝動部材と、その第２伝動部材に対向配置されると共に他方のドライブ軸に接続されて前記第１軸線回りに回転可能な第３伝動部材と、前記第１及び第２伝動部材間で変速しつつトルク伝達可能な第１変速機構と、前記第２及び第３伝動部材間で変速しつつトルク伝達可能な第２変速機構とを備えており、前記第１変速機構は、第１伝動部材の、第２伝動部材との対向面に在り且つ第１軸線を中心とする波形環状の第１伝動溝と、第２伝動部材の、第１伝動部材との対向面に在り且つ第２軸線を中心とする波形環状で波数が第１伝動溝とは異なる第２伝動溝と、第１及び第２伝動溝の複数の交差部に介装され、第１及び第２伝動溝を転動しながら第１及び第２伝動部材間の変速伝動を行う複数の第１転動体とを有し、また前記第２変速機構は、第２伝動部材の、第３伝動部材との対向面に在り且つ第２軸線を中心とする波形環状の第３伝動溝と、第３伝動部材の、第２伝動部材との対向面に在り且つ第１軸線を中心とする波形環状で波数が第３伝動溝とは異なる第４伝動溝と、第３及び第４伝動溝の複数の交差部に介装され、第３及び第４伝動溝を転動しながら第２及び第３伝動部材間の変速伝動を行う複数の第２転動体とを有し、前記第１伝動溝の波数をＺ１、前記第２伝動溝の波数をＺ２、前記第３伝動溝の波数をＺ３、前記第４伝動溝の波数をＺ４としたとき、
　次式　（Ｚ１／Ｚ２）×（Ｚ３／Ｚ４）＝２　
が成立することを第４の特徴としている。 In addition to any one of the first to third features, the present invention provides a first transmission integrally provided on one of the side wall plate portions with a first axis passing through the centers of the two boss portions as a central axis. A member, a main shaft portion connected to one of the drive shafts and rotatable about the first axis, and an eccentric shaft portion having a second axis eccentric from the first axis as a central axis are integrally coupled to each other. An eccentric rotating member, a second transmission member disposed opposite to the first transmission member and rotatably supported by the eccentric shaft portion, disposed opposite to the second transmission member and connected to the other drive shaft. A third transmission member that is rotatable about the first axis, a first transmission mechanism that is capable of transmitting torque while shifting between the first and second transmission members, and a transmission between the second and third transmission members. And a second speed change mechanism capable of transmitting torque, The first speed change mechanism is a first transmission member of the first transmission member, which is on the surface facing the second transmission member and has a wavy annular shape around the first axis, and the second transmission member. And a second annular groove having a wave shape centered on the second axis and having a wave number different from that of the first transmission groove, and a plurality of intersections of the first and second transmission grooves, A plurality of first rolling elements that perform transmission transmission between the first and second transmission members while rolling along the first and second transmission grooves, and the second transmission mechanism includes a second transmission member, The third transmission groove on the surface facing the three transmission members and centered on the second axis, and the third transmission member on the surface facing the second transmission member and centered on the first axis A fourth transmission groove having a wave shape and a wave number different from that of the third transmission groove, and a plurality of intersections of the third and fourth transmission grooves, and the third and fourth transmission grooves. A plurality of second rolling elements that perform transmission transmission between the second and third transmission members while rolling, wherein the wave number of the first transmission groove is Z1, the wave number of the second transmission groove is Z2, and the second When the wave number of the third transmission groove is Z3 and the wave number of the fourth transmission groove is Z4,
The following formula (Z1 / Z2) × (Z3 / Z4) = 2
The fourth feature is that is established.
　本発明の第１の特徴によれば、デフケースは、回転トルクを受けるリングギヤと、一対のドライブ軸を支持するボス部を内周端部に有し且つ外周端部がリングギヤの軸方向両端部にそれぞれ接合される一対の側壁板部とを備えるので、リングギヤがデフケースの一部（外周壁部）を構成することとなり、それだけデフケースの軽量化が達成され、差動装置の軽量化に寄与することができる。その上、デフケースの両側壁板部は、その両者の外側面間の軸方向距離が径方向内方、即ちボス部に向かうにつれて長くなるように形成されるので、デフケースの回転軸線を通る縦断面で見てデフケースの、回転軸線に関して片側部分（両側壁板部及びリングギヤの各片側部分）が裾拡がり状の山形状に形成され、これにより、デフケースの倒れ剛性を効果的に高めることができ、特に本発明のようにリングギヤが、ギヤ噛合部を通してスラスト荷重を受けるヘリカルギヤであっても、そのスラスト荷重に抗してデフケースの軸方向倒れを効果的に抑制可能であることから、デフケースの耐久性向上が図られる。更に各側壁板部が、その各側壁板部の、径方向でリングギヤ寄りの所定中間部から外周端部までの第１部分の肉厚を外周端部に近づくにつれて漸増させるように形成され、各側壁板部の第１部分の内側面が、リングギヤに向かって軸方向内方側に彎曲するので、外周端部寄りの第１部分で上記スラスト荷重を効率よく受け止めることができて、各側壁板部の重量増加を極力抑えながらデフケースの倒れ剛性を効率よく強化することができ、しかも各側壁板部（第１部分）の外周端部とリングギヤとの接合面（即ち嵌合代）を軸方向に極力広く確保可能となるから、各側壁板部とリングギヤとの結合強度が効果的に高められる。 According to the first feature of the present invention, the differential case has a ring gear that receives rotational torque, and a boss portion that supports a pair of drive shafts at the inner peripheral end portion, and the outer peripheral end portions at both axial end portions of the ring gear. Since the ring gear includes a pair of side wall plates that are joined to each other, the ring gear constitutes a part of the differential case (outer peripheral wall), and thus the weight of the differential case can be reduced, contributing to the weight reduction of the differential device. Can do. In addition, the both side wall plate portions of the differential case are formed so that the axial distance between the outer side surfaces of the differential case becomes longer inward in the radial direction, that is, toward the boss portion. In the differential case, one side portion of the rotation axis (one side portion of both side wall plate portions and ring gear) is formed in a hem-like mountain shape, which can effectively increase the falling rigidity of the differential case, In particular, even if the ring gear is a helical gear that receives a thrust load through the gear meshing portion as in the present invention, it is possible to effectively suppress the axial collapse of the differential case against the thrust load. Improvement is achieved. Further, each side wall plate portion is formed so as to gradually increase the thickness of the first portion from the predetermined intermediate portion close to the ring gear in the radial direction to the outer peripheral end portion of each side wall plate portion as it approaches the outer peripheral end portion, Since the inner surface of the first portion of the side wall plate portion bends inward in the axial direction toward the ring gear, the first portion near the outer peripheral end can efficiently receive the thrust load, and each side wall plate The differential case's falling rigidity can be efficiently enhanced while minimizing the increase in the weight of the part, and the joint surface (that is, the fitting allowance) between the outer peripheral end of each side wall plate (first part) and the ring gear is axial. Therefore, the coupling strength between the side wall plate portions and the ring gear can be effectively increased.
　また本発明の第２の特徴によれば、各側壁板部は、その各側壁板部の、前記所定中間部からボス部までの第２部分の肉厚をボス部に近づくにつれて漸増させるので、ボス部寄りの第２部分においても上記スラスト荷重を効率よく受け止めることができて、各側壁板部の重量増加を極力抑えながらデフケースの倒れ剛性を一層効率よく強化することができる。しかも各側壁板部（第２部分）の、厚肉となる内周端部にボス部を連ねることができるから、各側壁板部とボス部との結合強度が効果的に高められる。 According to the second feature of the present invention, each side wall plate portion gradually increases the thickness of the second portion of each side wall plate portion from the predetermined intermediate portion to the boss portion as it approaches the boss portion. The thrust load can be efficiently received also in the second portion near the boss portion, and the falling rigidity of the differential case can be further efficiently enhanced while suppressing the increase in the weight of each side wall plate portion as much as possible. Moreover, since the boss portion can be connected to the thick inner peripheral end portion of each side wall plate portion (second portion), the bonding strength between each side wall plate portion and the boss portion can be effectively increased.
　また本発明の第３の特徴によれば、各側壁板部の外周端部とリングギヤとの相互の接合面には段差が形成されるので、各側壁板部の外周端部とリングギヤとの軸方向位置決め精度及び結合強度を効果的に高めることができる。 According to the third feature of the present invention, since a step is formed on the joint surface between the outer peripheral end of each side wall plate and the ring gear, the shaft between the outer peripheral end of each side wall plate and the ring gear. Directional positioning accuracy and coupling strength can be effectively increased.
　また本発明の第４の特徴によれば、差動機構の第１及び第２伝動部材間では、波数が異なる波形環状の第１及び第２伝動溝相互の複数の交差部に介在する複数の第１転動体を介して（即ち周方向で複数箇所に分散して）トルク伝達が行われ、また、第２及び第３伝動部材間では、波数が異なる波形環状の第３及び第４伝動溝相互の複数の交差部に介在する複数の第２転動体を介して（即ち周方向で複数箇所に分散して）トルク伝達が行われるため、その各々の伝動要素の荷重負担が軽減されて強度増及び軽量化が図られる。しかも差動機構を軸方向に扁平に構成可能となるため、デフケース、延いては差動装置の扁平化に寄与することができ、またそのように扁平化しても、本発明のデフケースは前述のように倒れ剛性が高いことから、十分な実用強度を無理なく確保可能である。 Further, according to the fourth feature of the present invention, a plurality of intervening first and second transmission grooves having different wave numbers are interposed between the first and second transmission members of the differential mechanism. Torque is transmitted via the first rolling element (that is, distributed in a plurality of locations in the circumferential direction), and the wave-shaped third and fourth transmission grooves having different wave numbers between the second and third transmission members. Torque is transmitted via a plurality of second rolling elements interposed at a plurality of intersections (that is, distributed in a plurality of locations in the circumferential direction), so that the load burden on each transmission element is reduced and strength is increased. Increase and weight reduction are achieved. In addition, since the differential mechanism can be configured to be flat in the axial direction, it can contribute to the flattening of the differential case, and hence the differential device. In this way, since the collapsed rigidity is high, sufficient practical strength can be secured without difficulty.
図１は本発明の一実施形態に係る差動装置の縦断正面図である。（第１の実施の形態）FIG. 1 is a longitudinal front view of a differential according to an embodiment of the present invention. (First embodiment) 図２は前記差動装置の要部（差動機構）の分解斜視図である。（第１の実施の形態）FIG. 2 is an exploded perspective view of a main part (differential mechanism) of the differential device. (First embodiment) 図３は図１の３－３矢視断面図である。（第１の実施の形態）FIG. 3 is a cross-sectional view taken along arrow 3-3 in FIG. (First embodiment) 図４は図１の４－４矢視断面図である。（第１の実施の形態）4 is a cross-sectional view taken along arrow 4-4 of FIG. (First embodiment) 図５は図１の５－５矢視断面図である。（第１の実施の形態）FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. (First embodiment)
ａ１，ａ２・・第１，第２部分
Ｂ・・・・・ボス部
Ｃ・・・・・デフケース
Ｃａ，Ｃｂ・・第１，第２側壁板部
Ｃｇ・・・・リングギヤ
Ｄ・・・・・差動装置
ｍ・・・・・所定中間部
Ｓ１・・・・一方のドライブ軸としての右方の第１駆動車軸
Ｓ２・・・・他方のドライブ軸としての左方の第２駆動車軸
Ｔ１，Ｔ２・・第１，第２変速機構
Ｘ１，Ｘ２・・第１，第２軸線
３・・・・・差動機構
５・・・・・第１伝動部材
６・・・・・偏心回転部材
６ｊ・・・・主軸部
６ｅ・・・・偏心軸部
８・・・・・第２伝動部材
９・・・・・第３伝動部材
２３・・・・・第１転動体としての第１伝動ボール
２４，２５・・第３，第４伝動溝
２６・・・・・第２転動体としての第２伝動ボール a1, a2... first and second parts B .. boss C... differential case Ca, Cb .. first and second side wall plate Cg... ring gear D.・ Differential gear m... Predetermined intermediate portion S1... Right first drive axle S2 as one drive shaft... Left second drive axle T1 as the other drive shaft , T2,..., First and second speed change mechanisms X1, X2,..., First and second axis 3 ... differential mechanism 5 ... first transmission member 6 ... eccentric rotation member 6j ··· Main shaft portion 6e ··· Eccentric shaft portion 8 ··· 2nd transmission member 9 ··· 3rd transmission member 23 ··· 1st transmission as first rolling element Balls 24, 25,..., Third and fourth transmission grooves 26... Second transmission balls as second rolling elements
　本発明の実施形態を添付図面に基づいて以下に説明する。 Embodiments of the present invention will be described below with reference to the accompanying drawings.
第１の実施の形態First embodiment
　先ず、図１～図５に示す本発明の一実施形態を説明する。図１において、自動車のミッションケース１内には、伝動装置としての差動装置Ｄが変速装置と共に収容される。 First, an embodiment of the present invention shown in FIGS. 1 to 5 will be described. In FIG. 1, a differential device D as a transmission device is housed in a transmission case 1 of an automobile together with a transmission.
　この差動装置Ｄは、前記変速装置の出力側に連動回転するリングギヤＣｇの回転を、差動装置Ｄの中心軸線即ち第１軸線Ｘ１上に相対回転可能に並ぶ左右の駆動車軸Ｓ１，Ｓ２（即ちドライブ軸）に対して、両駆動車軸Ｓ１，Ｓ２相互の差動回転を許容しつつ分配する。尚、各々の駆動車軸Ｓ１，Ｓ２とミッションケース１との間は、シール部材４，４′でシールされる。 In the differential device D, the left and right drive axles S1, S2 (in which the rotation of the ring gear Cg that rotates in conjunction with the output side of the transmission is aligned on the central axis of the differential device D, that is, the first axis X1, are relatively rotatable. That is, with respect to the drive shaft), the drive shafts S1 and S2 are distributed while allowing differential rotation between them. The drive axles S1, S2 and the transmission case 1 are sealed with seal members 4, 4 '.
　差動装置Ｄは、ミッションケース１に第１軸線Ｘ１回りに回転可能に支持されるデフケースＣと、そのデフケースＣ内に収容される後述の差動機構３とで構成される。デフケースＣは、短円筒状のギヤ本体の外周に斜歯Ｃｇａを設けたヘリカルギヤよりなるリングギヤＣｇと、そのリングギヤＣｇの軸方向両端部に外周端部がそれぞれ接合される左右一対の第１，第２側壁板部Ｃａ，Ｃｂとを備える。 The differential device D includes a differential case C that is supported by the mission case 1 so as to be rotatable about the first axis X1, and a differential mechanism 3 described later that is accommodated in the differential case C. The differential case C includes a ring gear Cg made of a helical gear having oblique teeth Cga provided on the outer periphery of a short cylindrical gear body, and a pair of left and right first and first pairs whose outer peripheral ends are joined to both axial ends of the ring gear Cg. Two side wall plate portions Ca and Cb are provided.
　その両側壁板部Ｃａ，Ｃｂは、各々の内周端部においてボス部Ｂを一体に有しており、そのボス部Ｂの外周部は、ミッションケース１に軸受２，２′を介して第１軸線Ｘ１回りに回転自在に支持される。またボス部Ｂの内周部には、第１軸線Ｘ１を回転軸線とする第１，第２駆動車軸Ｓ１，Ｓ２がそれぞれ回転自在に嵌合、支持される。 The both side wall plate portions Ca and Cb integrally have a boss portion B at each inner peripheral end, and the outer peripheral portion of the boss portion B is connected to the transmission case 1 via bearings 2 and 2 '. It is supported so as to be rotatable about one axis X1. Further, first and second drive axles S1 and S2 having the first axis X1 as a rotation axis are rotatably fitted and supported on the inner peripheral portion of the boss portion B, respectively.
　図１に明示したように、デフケースＣの第１，第２側壁板部Ｃａ，Ｃｂは、その両者の外側面間の軸方向距離（即ちデフケースＣの軸方向幅）が径方向内方に向かう（即ちボス部Ｂに近づく）につれて長くなるように形成される。しかもその各側壁板部Ｃａ，Ｃｂは、それらの、径方向でリングギヤＣｇ寄りの所定中間部ｍから外周端部までの第１部分ａ１の肉厚を外周端部に近づくにつれて漸増させるように形成される。また、各側壁板部Ｃａ，Ｃｂの前記第１部分ａ１の内側面（即ちデフケースＣの内部空間に臨む内面）は、リングギヤＣｇに向かって軸方向内方側に彎曲している。更に各側壁板部Ｃａ，Ｃｂは、それらの、前記所定中間部ｍからボス部Ｂまでの第２部分ａ２の肉厚をボス部Ｂに近づくにつれて漸増させるように形成される。 As clearly shown in FIG. 1, the first and second side wall plate portions Ca and Cb of the differential case C have an axial distance between their outer surfaces (that is, an axial width of the differential case C) directed radially inward. It is formed so as to become longer (that is, closer to the boss B). Moreover, each of the side wall plate portions Ca and Cb is formed so as to gradually increase the thickness of the first portion a1 from the predetermined intermediate portion m near the ring gear Cg in the radial direction to the outer peripheral end portion as it approaches the outer peripheral end portion. Is done. Further, the inner side surfaces of the first portions a1 of the side wall plate portions Ca and Cb (that is, the inner surfaces facing the inner space of the differential case C) are bent inward in the axial direction toward the ring gear Cg. Further, the side wall plate portions Ca and Cb are formed so as to gradually increase the thickness of the second portion a2 from the predetermined intermediate portion m to the boss portion B as they approach the boss portion B.
　第１，第２側壁板部Ｃａ，Ｃｂの外周端部とリングギヤＣｇとの相互の接合面間は、溶接、接着、かしめ等の適当な結合手段により一体的に接合される。またその接合面には、段差ｓが形成されており、この段差ｓにより、各側壁板部Ｃａ，Ｃｂの外周端部とリングギヤＣｇとの互いの軸方向位置決め精度及び結合強度が効果的に高められる。 The joint surfaces between the outer peripheral ends of the first and second side wall plate portions Ca and Cb and the ring gear Cg are integrally joined by appropriate joining means such as welding, adhesion, and caulking. Further, a step s is formed on the joint surface, and the step s effectively enhances the axial positioning accuracy and the coupling strength between the outer peripheral end portions of the side wall plate portions Ca and Cb and the ring gear Cg. It is done.
　而して、上記した本実施形態のデフケース構造によれば、リングギヤＣｇがデフケースＣの一部（外周壁部）を構成するため、それだけデフケースＣ、延いては差動装置Ｄの軽量化が達成される。その上、デフケースの第１，第２側壁板部Ｃａ，Ｃｂは、その両者の外側面間の軸方向距離が径方向内方に向かうにつれて長くなるように形成されるので、デフケースＣの縦断面（図１）で見てデフケースＣの、第１軸線Ｘ１に関して片側部分が裾拡がり状の山形状に形成され、これにより、デフケースＣの倒れ剛性が効果的に高められる。従って、リングギヤＣｇが、ギヤ噛合部を通して大きなスラスト荷重を受けるヘリカルギヤであっても、スラスト荷重に抗してデフケースＣの軸方向倒れが効果的に抑制可能となる。更に各側壁板部Ｃａ，Ｃｂが、それらのリングギヤＣｇ寄りの前記第１部分ａ１の肉厚を外周端部に近づくにつれて漸増させるように（即ち先拡がり状に）形成され、且つその第１部分ａ１の内側面がリングギヤＣｇに向かって軸方向内方側に彎曲するため、外周端部寄りの第１部分ａ１でスラスト荷重が効率よく受け止められ、従って、各側壁板部Ｃａ，Ｃｂの重量増加を極力抑えつつデフケースＣの倒れ剛性が効率よく強化可能となる。しかも上記第１部分ａ１の外周端部とリングギヤＣｇとの接合面（即ち嵌合代）を軸方向に極力広く確保可能となるから、各側壁板部Ｃａ，ＣｂとリングギヤＣｇとの結合強度が効果的に高められる。 Thus, according to the differential case structure of the present embodiment described above, the ring gear Cg constitutes a part (outer peripheral wall portion) of the differential case C, so that the weight reduction of the differential case C and thus the differential device D is achieved. Is done. In addition, since the first and second side wall plate portions Ca and Cb of the differential case are formed such that the axial distance between the outer side surfaces of the differential case becomes longer inward in the radial direction, the longitudinal section of the differential case C As shown in FIG. 1, the differential case C is formed in a mountain shape in which one side of the differential axis C with respect to the first axis X <b> 1 is widened, thereby effectively increasing the falling rigidity of the differential case C. Therefore, even if the ring gear Cg is a helical gear that receives a large thrust load through the gear meshing portion, the axial fall of the differential case C can be effectively suppressed against the thrust load. Further, each of the side wall plate portions Ca and Cb is formed so as to gradually increase the thickness of the first portion a1 near the ring gear Cg as it approaches the outer peripheral end portion (that is, in a flared shape), and the first portion. Since the inner side surface of a1 bends inward in the axial direction toward the ring gear Cg, the thrust load is efficiently received by the first portion a1 near the outer peripheral end, and therefore the weight of each side wall plate portion Ca, Cb increases. The fall rigidity of the differential case C can be efficiently reinforced while suppressing as much as possible. In addition, since the joint surface (that is, the fitting allowance) between the outer peripheral end of the first portion a1 and the ring gear Cg can be secured as much as possible in the axial direction, the coupling strength between the side wall plate portions Ca and Cb and the ring gear Cg is high. Effectively enhanced.
　さらに各側壁板部Ｃａ，Ｃｂは、それらのボス部Ｂ寄りの第２部分ａ２の肉厚をボス部Ｂに近づくにつれて漸増させるので、この第２部分ａ２においてもスラスト荷重を効率よく受け止めてボス部Ｂ側に伝達でき、各側壁板部Ｃａ，Ｃｂの重量増加を極力抑えながらデフケースＣの倒れ剛性が一層効率よく強化可能となる。しかも上記第２部分ａ２の、厚肉となる内周端部にボス部Ｂを連ねることができるから、各側壁板部Ｃａ，Ｃｂとボス部Ｂとの結合強度が効果的に高められる。 Further, each side wall plate portion Ca, Cb gradually increases the thickness of the second portion a2 near the boss portion B as it approaches the boss portion B, so that the thrust load is also efficiently received at the second portion a2. It can be transmitted to the part B side, and the falling rigidity of the differential case C can be more efficiently enhanced while suppressing the increase in weight of the side wall plate parts Ca and Cb as much as possible. Moreover, since the boss portion B can be connected to the thick inner peripheral end portion of the second portion a2, the coupling strength between the side wall plate portions Ca and Cb and the boss portion B is effectively enhanced.
　次にデフケースＣ内の差動機構３の構造を説明する。差動機構３は、第１側壁板部Ｃａ（具体的には厚肉の前記第２部分ａ２）に一体的に設けられて第１軸線Ｘ１回りに回転自在な第１伝動部材５と、第１駆動車軸Ｓ１にスプライン嵌合１６されて第１軸線Ｘ１回りに回転自在な主軸部６ｊ、および第１軸線Ｘ１から所定量ｅだけ偏心した第２軸線Ｘ２を中心軸線とする偏心軸部６ｅを互いに一体に連結してなる偏心回転部材６と、第１伝動部材５に一側部が対向配置され且つ前記偏心軸部６ｅに軸受７を介して回転自在に支持される円環状の第２伝動部材８と、第２伝動部材８の他側部に対向配置されると共に第２駆動車軸Ｓ２にスプライン嵌合１７されて第１軸線Ｘ１回りに回転自在な円環状の第３伝動部材９と、第１及び第２伝動部材５，８間で変速しつつトルク伝達可能な第１変速機構Ｔ１と、第２及び第３伝動部材８，９間で変速しつつトルク伝達可能な第２変速機構Ｔ２とを備える。 Next, the structure of the differential mechanism 3 in the differential case C will be described. The differential mechanism 3 includes a first transmission member 5 provided integrally with the first side wall plate portion Ca (specifically, the thick second portion a2) and rotatable around the first axis X1, A main shaft portion 6j that is spline-fitted 16 to the first drive axle S1 and is rotatable about the first axis X1, and an eccentric shaft portion 6e that is centered on a second axis X2 that is eccentric from the first axis X1 by a predetermined amount e. An eccentric rotating member 6 integrally connected to each other, and an annular second transmission whose one side is opposed to the first transmission member 5 and rotatably supported by the eccentric shaft portion 6e via a bearing 7. An annular third transmission member 9 that is disposed opposite to the other side of the member 8 and the second transmission member 8 and is spline-fitted 17 to the second drive axle S2 and rotatable about the first axis X1; A first transmission mechanism capable of transmitting torque while shifting between the first and second transmission members 5 and 8. 1, and a second transmission mechanism T2 which transmit the torque while shifting between the second and third transmission members 8,9.
　而して、第１軸線Ｘ１回りに回転自在に支持される主軸部６ｊを有した偏心回転部材６の偏心軸部６ｅに第２伝動部材８が第２軸線Ｘ２回りに回転自在に嵌合支持されることで、その第２伝動部材８は、偏心回転部材６の第１軸線Ｘ１回りの回転に伴い、それの偏心軸部６ｅに対し第２軸線Ｘ２回りに自転しつつ、主軸部６ｊに対し第１軸線Ｘ１回りに公転可能である。 Thus, the second transmission member 8 is fitted to and supported by the eccentric shaft portion 6e of the eccentric rotating member 6 having the main shaft portion 6j rotatably supported about the first axis X1 so as to be rotatable about the second axis X2. As a result, the second transmission member 8 rotates around the first axis X1 of the eccentric rotation member 6 and rotates around the second axis X2 with respect to the eccentric shaft portion 6e, while rotating to the main shaft portion 6j. On the other hand, it can revolve around the first axis X1.
　また第２伝動部材８は、偏心回転部材６の偏心軸部６ｅに軸受７を介して回転自在に支持される円環状の第１半体８ａと、その第１半体８ａに後述するバランスウェイトＷの収容空間ＳＰを挟んで対向する円環状の第２半体８ｂと、その収容空間ＳＰを囲むようにして両半体８ａ，８ｂ間を一体的に連結する基本的に円筒状の連結部材８ｃとを備えていて、第１半体８ａと第１伝動部材５との間に前記第１変速機構Ｔ１が、また第２半体８ｂと第３伝動部材９との間に前記第２変速機構Ｔ２がそれぞれ設けられる。 The second transmission member 8 includes an annular first half 8a that is rotatably supported by the eccentric shaft portion 6e of the eccentric rotating member 6 via a bearing 7, and a balance weight described later on the first half 8a. An annular second half 8b opposed across the accommodation space SP of W, and a basically cylindrical connecting member 8c integrally connecting the two halves 8a, 8b so as to surround the accommodation space SP. The first transmission mechanism T1 is provided between the first half body 8a and the first transmission member 5, and the second transmission mechanism T2 is provided between the second half body 8b and the third transmission member 9. Are provided respectively.
　また第３伝動部材９は、第２駆動車軸Ｓ２にスプライン嵌合１７されて第１軸線Ｘ１回りに回転自在な主軸部６ｊと、その主軸部６ｊの内端部に同軸状に連設される円板部９ｃとを結合一体化して構成される。尚、第２側壁板部Ｃｂの内側面と第３伝動部材９（円板部９ｃの背面）との間には、スラストワッシャ１５が相対回転自在に介装される。 The third transmission member 9 is spline-fitted 17 to the second drive axle S2 and is connected coaxially to the main shaft portion 6j rotatable around the first axis X1 and the inner end portion of the main shaft portion 6j. The disc portion 9c is combined and integrated. A thrust washer 15 is interposed between the inner side surface of the second side wall plate portion Cb and the third transmission member 9 (the back surface of the disc portion 9c) so as to be relatively rotatable.
　更に差動機構３は、第１軸線Ｘ１を挟んで偏心回転部材６の偏心軸部６ｅ及び第２伝動部材８の総合重心Ｇとは逆位相であり且つその総合重心Ｇの回転半径よりも大なる回転半径を有していて偏心回転部材６の主軸部６ｊに取付けられるバランスウェイトＷを備えている。このバランスウェイトＷは、環状の取付基部Ｗｍと、その取付基部Ｗｍの周方向特定領域に固設される重錘部Ｗｗとから構成される。 Further, the differential mechanism 3 is opposite in phase to the eccentric shaft portion 6e of the eccentric rotating member 6 and the total center of gravity G of the second transmission member 8 across the first axis X1, and larger than the rotational radius of the total center of gravity G. And a balance weight W attached to the main shaft portion 6j of the eccentric rotating member 6. This balance weight W is comprised from the cyclic | annular attachment base Wm and the weight part Ww fixedly provided in the circumferential direction specific area | region of the attachment base Wm.
　第２伝動部材８（連結部材８ｃ）の内部空間は、バランスウェイトＷを収容する収容空間ＳＰとなっている。そして、偏心回転部材６の主軸部６ｊは、その内端部が前記収容空間ＳＰに延出しており、その延出端部６ｊａの外周にバランスウェイトＷが装着される。そして、前記取付基部Ｗｍは、主軸部６ｊの延出端部６ｊａ外周に嵌合されており、その嵌合面間には、その間の軸方向摺動は許容するが相対回転を規制する回り止め用の平坦な係合面１４が設けられる。バランスウェイトＷの主軸部６ｊへの固定は、前記取付基部Ｗｍの主軸部６ｊからの離脱を阻止する抜け止め部材としてのサークリップ等の止輪１０を主軸部６ｊの延出端部６ｊａに着脱可能に装着することで行われる。その装着のために、主軸部６ｊの延出端部６ｊａの外周には、止輪１０が弾力的に係止可能な係止溝が凹設される。 The internal space of the second transmission member 8 (the connecting member 8c) is an accommodation space SP for accommodating the balance weight W. The main shaft portion 6j of the eccentric rotating member 6 has an inner end portion extending into the accommodation space SP, and a balance weight W is attached to the outer periphery of the extended end portion 6ja. The mounting base portion Wm is fitted to the outer periphery of the extended end portion 6ja of the main shaft portion 6j, and the anti-rotation that allows axial sliding between the fitting surfaces but restricts relative rotation. A flat engagement surface 14 is provided. The balance weight W is fixed to the main shaft portion 6j by attaching or detaching a retaining ring 10 such as a circlip as a retaining member that prevents the attachment base portion Wm from being detached from the main shaft portion 6j to the extension end portion 6ja of the main shaft portion 6j. It is done by wearing it as possible. For the mounting, a locking groove that can elastically lock the retaining ring 10 is formed in the outer periphery of the extended end portion 6ja of the main shaft portion 6j.
　図１～図３に示すように、第１伝動部材５の、第２伝動部材８の一側面（即ち第１半体８ａ）に対向する内側面には、第１軸線Ｘ１を中心とした波形環状の第１伝動溝２１が形成され、この第１伝動溝２１は、図示例では第１軸線Ｘ１を中心とする仮想円を基礎円としたハイポトロコイド曲線に沿って周方向に延びている。一方、第２伝動部材８の、第１伝動部材５に対向する一側面（第１半体８ａ）には、第２軸線Ｘ２を中心とした波形環状の第２伝動溝２２が形成される。この第２伝動溝２２は、図示例では第２軸線Ｘ２を中心とする仮想円を基礎円としたエピトロコイド曲線に沿って周方向に延びており、上記第１伝動溝２１の波数よりも少ない波数を有して第１伝動溝２１と複数箇所で交差する。これら第１伝動溝２１及び第２伝動溝２２の交差部（即ち重なり部）には、第１転動体としての複数の第１伝動ボール２３が介装されており、各々の第１伝動ボール２３は、それら第１及び第２伝動溝２１，２２の内側面を転動自在である。 As shown in FIGS. 1 to 3, the inner surface of the first transmission member 5 facing the one side surface (that is, the first half 8a) of the second transmission member 8 has a waveform centered on the first axis X1. An annular first transmission groove 21 is formed, and the first transmission groove 21 extends in the circumferential direction along a hypotrochoid curve having a virtual circle centered on the first axis X1 in the illustrated example. On the other hand, a corrugated annular second transmission groove 22 centering on the second axis X2 is formed on one side surface (first half 8a) 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 smaller than the wave number of the first transmission groove 21. It has a wave number and intersects the first transmission groove 21 at a plurality of locations. A plurality of first transmission balls 23 as first rolling elements are interposed at intersections (that is, overlapping portions) of the first transmission grooves 21 and the second transmission grooves 22, and each of the first transmission balls 23. Can roll on the inner surfaces of the first and second transmission grooves 21 and 22.
　第１伝動部材５及び第２伝動部材８（第１半体８ａ）の相対向面間には、円環状の扁平な第１保持部材Ｈ１が介装される。この第１保持部材Ｈ１は、複数の第１伝動ボール２３の、第１、第２伝動溝２１，２２相互の交差部での両伝動溝２１，２２への係合状態を維持し得るように、複数の第１転動ボール２３をそれらの相互間隔を一定に規制しつつ回転自在に保持する複数の円形の保持孔３１を有している。これにより、各々の第１伝動ボール２３は、第１、第２伝動溝２１，２２の各々の曲率急変部を通過する際にも溝内での暴れが効果的に抑制されるため、その曲率急変部でもスムーズに転動可能となり、伝動効率が高められる。 Between the opposing surfaces of the first transmission member 5 and the second transmission member 8 (first half 8a), an annular flat first holding member H1 is interposed. The first holding member H1 can maintain the engaged state of the plurality of first transmission balls 23 in both the transmission grooves 21 and 22 at the intersections of the first and second transmission grooves 21 and 22. The plurality of first rolling balls 23 are provided with a plurality of circular holding holes 31 for holding the plurality of first rolling balls 23 in a freely rotating manner while keeping their mutual spacing constant. Thereby, since each 1st transmission ball 23 passes through each curvature sudden change part of each of the 1st, 2nd transmission grooves 21 and 22, the turbulence in a groove is controlled effectively, the curvature Rolling can be performed smoothly even in sudden changes, and transmission efficiency is improved.
　また、図１，２，４に示すように、第２伝動部材８の他側面（即ち第２半体８ｂ）には、第２軸線Ｘ２を中心とした波形環状の第３伝動溝２４が形成され、この第３伝動溝２４は、図示例では第２軸線Ｘ２を中心とする仮想円を基礎円としたハイポトロコイド曲線に沿って周方向に延びている。一方、第３伝動部材９の、第２伝動部材８との対向面すなわち円板部９ｃの内側面には、第１軸線Ｘ１を中心とした波形環状の第４伝動溝２５が形成される。この第４伝動溝２５は、図示例では第１軸線Ｘ１を中心とする仮想円を基礎円としたエピトロコイド曲線に沿って周方向に延びており、上記第３伝動溝２４の波数よりも少ない波数を有して第３伝動溝２４と複数箇所で交差する。これら第３伝動溝２４及び第４伝動溝２５の交差部（重なり部）には、第２転動体としての複数の第２伝動ボール２６が介装されており、各々の第２伝動ボール２６は、それら第３及び第４伝動溝２４，２５の内側面を転動自在である。 As shown in FIGS. 1, 2, and 4, a corrugated annular third transmission groove 24 centering on the second axis X <b> 2 is formed on the other side surface of the second transmission member 8 (that is, the second half 8 b). In the illustrated example, the third transmission groove 24 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 surface of the third transmission member 9 facing the second transmission member 8, that is, on the inner side surface of the disc portion 9c, a corrugated annular fourth transmission groove 25 centering on the first axis X1 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 smaller than the wave number of the third transmission groove 24. It has a wave number and intersects with the third transmission groove 24 at a plurality of locations. A plurality of second transmission balls 26 as second rolling elements are interposed at intersections (overlapping portions) of the third transmission groove 24 and the fourth transmission groove 25, and each second transmission ball 26 is The inner side surfaces of the third and fourth transmission grooves 24 and 25 can roll freely.
　第３伝動部材９及び第２伝動部材８（第２半体８ｂ）の相対向面間には、円環状の扁平な第２保持部材Ｈ２が介装される。この第２保持部材Ｈ２は、複数の第２伝動ボール２６の、第３、第４伝動溝２４，２５相互の交差部での両伝動溝２４，２５への係合状態を維持し得るように、複数の第２転動ボール２６をそれらの相互間隔を一定に規制しつつ回転自在に保持する複数の円形の保持孔３２を有している。これにより、各々の第２伝動ボール２６は、第３、第４伝動溝２４，２５の各々の曲率急変部を通過する際にも溝内での暴れが効果的に抑制されるため、その曲率急変部でもスムーズに転動可能となり、伝動効率が高められる。 Between the opposing surfaces of the third transmission member 9 and the second transmission member 8 (second half 8b), an annular flat second holding member H2 is interposed. The second holding member H2 can maintain the engagement state of the plurality of second transmission balls 26 with the transmission grooves 24 and 25 at the intersections of the third and fourth transmission grooves 24 and 25. The plurality of second rolling balls 26 are provided with a plurality of circular holding holes 32 for holding the plurality of second rolling balls 26 so as to be rotatable while restricting their mutual intervals to be constant. As a result, each second transmission ball 26 is effectively prevented from violating in the groove even when passing through the suddenly changing portions of the third and fourth transmission grooves 24 and 25, so that the curvature thereof is reduced. Rolling can be performed smoothly even in sudden changes, and transmission efficiency is improved.
　以上において、第１伝動溝２１の波数をＺ１、第２伝動溝２２の波数をＺ２、第３伝動溝２４の波数をＺ３、第４伝動溝２５の波数をＺ４としたとき、下記式が成立するように、第１～第４伝動溝２１，２２，２４，２５は形成される。
（Ｚ１／Ｚ２）×（Ｚ３／Ｚ４）＝２ In the above, when 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, the following equation is established. Thus, the first to fourth transmission grooves 21, 22, 24, 25 are formed.
(Z1 / Z2) × (Z3 / Z4) = 2
　望ましくは、図示例のように、Ｚ１＝８、Ｚ２＝６、Ｚ３＝６、Ｚ４＝４とするか、又はＺ１＝６、Ｚ２＝４、Ｚ３＝８、Ｚ４＝６とするとよい。 Desirably, Z1 = 8, Z2 = 6, Z3 = 6, Z4 = 4, or Z1 = 6, Z2 = 4, Z3 = 8, and Z4 = 6, as shown in the illustrated example.
　尚、図示例では、８波の第１伝動溝２１と６波の第２伝動溝２２とが７箇所で交差し、この７箇所の交差部（重なり部）に７個の第１伝動ボール２３が介装され、また６波の第３伝動溝２４と４波の第４伝動溝２５とが５箇所で交差し、この５箇所の交差部（重なり部）に５個の第２伝動ボール２６が介装される。 In the illustrated example, the eight-wave first transmission groove 21 and the six-wave second transmission groove 22 intersect at seven locations, and seven first transmission balls 23 at the seven intersection portions (overlapping portions). The six-wave third transmission groove 24 and the four-wave fourth transmission groove 25 intersect at five locations, and five second transmission balls 26 at the five intersections (overlapping portions). Is installed.
　而して、第１伝動溝２１、第２伝動溝２２及び第１伝動ボール２３は互いに協働して、第１伝動部材５及び第２伝動部材８間で変速しつつトルク伝達可能な第１変速機構Ｔ１を構成し、また第３伝動溝２４、第４伝動溝２５及び第２伝動ボール２６は互いに協働して、第２伝動部材８及び第３伝動部材９間で変速しつつトルク伝達可能な第２変速機構Ｔ２を構成する。 Thus, the first transmission groove 21, the second transmission groove 22, and the first transmission ball 23 cooperate with each other and can transmit torque while shifting between the first transmission member 5 and the second transmission member 8. The transmission mechanism T1 is configured, and the third transmission groove 24, the fourth transmission groove 25, and the second transmission ball 26 cooperate with each other to transmit torque while shifting between the second transmission member 8 and the third transmission member 9. A possible second speed change mechanism T2 is configured.
　次に、前記実施形態の作用について説明する。 Next, the operation of the embodiment will be described.
　いま、例えば右方の第１駆動車軸Ｓ１を固定することで偏心回転部材６（従って偏心軸部６ｅ）を固定した状態において、エンジンからの動力でリングギヤＣｇが駆動され、デフケースＣ、従って第１伝動部材５を第１軸線Ｘ１回りに回転させると、第１伝動部材５の８波の第１伝動溝２１が第２伝動部材８の６波の第２伝動溝２２を第１伝動ボール２３を介して駆動するので、第１伝動部材５が８／６の増速比を以て第２伝動部材８を駆動することになる。そして、この第２伝動部材８の回転によれば、第２伝動部材８の６波の第３伝動溝２４が第３伝動部材９の円板部９ｃの４波の第４伝動溝２５を第２伝動ボール２６を介して駆動するので、第２伝動部材８が６／４の増速比を以て第３伝動部材９を駆動することになる。 Now, for example, in a state where the eccentric rotary member 6 (and hence the eccentric shaft portion 6e) is fixed by fixing the right first drive axle S1, the ring gear Cg is driven by the power from the engine, and the differential case C and therefore the first When the transmission member 5 is rotated about the first axis X 1, the first transmission groove 21 of the first transmission member 5 is replaced with the second transmission groove 22 of the sixth transmission wave of the second transmission member 8 and the first transmission ball 23. Therefore, the first transmission member 5 drives the second transmission member 8 with a speed increasing ratio of 8/6. According to the rotation of the second transmission member 8, the six-wave third transmission groove 24 of the second transmission member 8 replaces the four-wave fourth transmission groove 25 of the disk portion 9 c of the third transmission member 9. Since the second transmission ball 26 is driven through the second transmission ball 26, the second transmission member 8 drives the third transmission member 9 with a speed increasing ratio of 6/4.
　結局、第１伝動部材５は、
（Ｚ１／Ｚ２）×（Ｚ３／Ｚ４）＝（８／６）×（６／４）＝２
の増速比を以て第３伝動部材９を駆動することになる。 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.
　一方、左方の第２駆動車軸Ｓ２を固定することで第３伝動部材９を固定した状態において、デフケースＣ（従って第１伝動部材５）を回転させると、第１伝動部材５の回転駆動力と、第２伝動部材８の、不動の第３伝動部材９に対する駆動反力とにより、第２伝動部材８は、偏心回転部材６の偏心軸部６ｅ（第２軸線Ｘ２）に対し自転しながら第１軸線Ｘ１回りに公転して、偏心軸部６ｅを第１軸線Ｘ１回りに駆動する。その結果、第１伝動部材５は、２倍の増速比を以て偏心回転部材６を駆動することになる。 On the other hand, when the differential case C (and hence the first transmission member 5) is rotated in a state in which the third transmission member 9 is fixed by fixing the left second drive axle S2, the rotational driving force of the first transmission member 5 is rotated. The second transmission member 8 rotates with respect to the eccentric shaft portion 6e (second axis X2) of the eccentric rotation member 6 by the driving reaction force of the second transmission member 8 against the stationary third transmission member 9. Revolving around the first axis X1, 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.
　而して、偏心回転部材６及び第３伝動部材９の負荷が相互にバランスしたり、相互に変化したりすると、第２伝動部材８の自転量及び公転量が無段階に変化し、偏心回転部材６及び第３伝動部材９の回転数の平均値が第１伝動部材５の回転数と等しくなる。こうして、第１伝動部材５の回転は、偏心回転部材６及び第３伝動部材９に分配され、したがってリングギヤＣｇからデフケースＣに伝達された回転力を左右の駆動車軸Ｓ１，Ｓ２に分配することができる。 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.
　その際、Ｚ１＝８、Ｚ２＝６、Ｚ３＝６、Ｚ４＝４とするか、又はＺ１＝６、Ｚ２＝４、Ｚ３＝８、Ｚ４＝６とすることにより、差動機能を確保しつゝ構造の簡素化を図ることができる。 At that time, Z1 = 8, Z2 = 6, Z3 = 6, Z4 = 4, or Z1 = 6, Z2 = 4, Z3 = 8, Z4 = 6 to ensure the differential function. Simplification of the eaves structure can be achieved.
　ところで、この差動装置Ｄにおいて、第１伝動部材５の回転トルクは、第１伝動溝２１、複数の第１伝動ボール２３及び第２伝動溝２２を介して第２伝動部材８に、また第２伝動部材８の回転トルクは、第３伝動溝２４、複数の第２伝動ボール２６及び第４伝動溝２５を介して第３伝動部材９にそれぞれ伝達されるので、第１伝動部材５と第２伝動部材８、第２伝動部材８と第３伝動部材９の各間では、トルク伝達が第１及び第２伝動ボール２３，２６が存在する複数箇所に分散して行われることになり、第１～第３伝動部材５，８，９及び第１、第２伝動ボール２３，２６等の各伝動要素の強度増及び軽量化を図ることができる。 By the way, in this differential device D, the rotational torque of the first transmission member 5 is applied to the second transmission member 8 via the first transmission groove 21, the plurality of first transmission balls 23 and the second transmission groove 22, and also to the second transmission member 8. The rotational torque of the second transmission member 8 is transmitted to the third transmission member 9 through the third transmission groove 24, the plurality of second transmission balls 26, and the fourth transmission groove 25, respectively. Between each of the second transmission member 8, the second transmission member 8 and the third transmission member 9, torque transmission is performed in a distributed manner at a plurality of locations where the first and second transmission balls 23 and 26 exist. The strength and weight of each transmission element such as the first to third transmission members 5, 8, 9 and the first and second transmission balls 23, 26 can be increased.
　以上、本発明の実施形態を説明したが、本発明はその要旨を逸脱しない範囲で種々の設計変更を行うことが可能である。 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.
　例えば、前記実施形態の差動装置Ｄとしては、動力源からデフケースＣ（第１伝動部材５）に入力された動力を、第２伝動部材８や第１，第２変速機構Ｔ１，Ｔ２を介して偏心回転部材６及び第３伝動部材９に差動回転を許容しつつ分配するようにしたものを示したが、本発明は、実施形態以外の種々の差動装置、例えばピニオン（差動ギヤ）とこれに噛合する一対のサイドギヤとを含む従来周知の歯車式の差動装置に適用してもよい。 For example, in the differential device D of the embodiment, the power input from the power source to the differential case C (first transmission member 5) is transmitted via the second transmission member 8 and the first and second transmission mechanisms T1 and T2. In this embodiment, the eccentric rotation member 6 and the third transmission member 9 are distributed while allowing differential rotation. However, the present invention is applicable to various differential devices other than the embodiment, such as pinions (differential gears). ) And a pair of side gears meshed therewith, it may be applied to a conventionally known gear-type differential device.
　また、前記実施形態では、差動装置Ｄを自動車のミッションケースＭ内に収容しているが、本発明の差動装置は自動車用の差動装置に限定されるものではなく、種々の機械装置用の差動装置として実施可能である。 Moreover, in the said embodiment, although the differential gear D is accommodated in the mission case M of a motor vehicle, the differential gear of this invention is not limited to the differential gear for motor vehicles, Various mechanical devices It can be implemented as a differential device.
　また、前記実施形態では、差動装置Ｄを、左・右輪伝動系に適用して、左右の駆動車軸Ｓ１，Ｓ２に対し差動回転を許容しつつ動力を分配するものを示したが、本発明では、差動装置を前・後輪駆動車両における前・後輪伝動系に適用して、前後の駆動車輪に対し差動回転を許容しつつ動力を分配するようにしてもよい。 In the above-described 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 to the front / rear drive wheels while allowing differential rotation.
　また前記実施形態の第２伝動部材８は、第１，第２半体８ａ，８ｂ及び連結部材８ｃから構成されていたが、第２伝動部材８は、単一の部材の一方の面に第２伝動溝２２が、他方の面に第３伝動溝２４がそれぞれ設けられたものであってもよい。 Moreover, although the 2nd transmission member 8 of the said embodiment was comprised from the 1st, 2nd half bodies 8a and 8b and the connection member 8c, the 2nd transmission member 8 is the 1st on one surface of a single member. The two transmission grooves 22 may be provided with the third transmission groove 24 on the other surface.
　また、前記実施形態では、第１，第２変速機構Ｔ１，Ｔ２として何れも転動ボール式変速機構を用いたものを示したが、本発明の第１，第２変速機構のうちの少なくとも一方の変速機構は、前記実施形態の構造に限定されない。即ち、偏心回転部材と、それの回転に連動して第２軸線回りの自転及び第１軸線回りの公転が可能な第２伝動部材とを少なくとも含む種々の変速機構、例えば内接式遊星歯車機構や、種々の構造のサイクロイド減速機（増速機）或いはトロコイド減速機（増速機）を、本発明の第１，第２変速機構のうちの少なくとも一方に適用するようにしてもよい。 In the above-described embodiment, the first and second transmission mechanisms T1 and T2 are each a rolling ball type transmission mechanism. However, at least one of the first and second transmission mechanisms of the present invention is used. The speed change mechanism is not limited to the structure of the above embodiment. That is, various speed change mechanisms including at least an eccentric rotating member and a second transmission member capable of rotating around the second axis and revolving around the first axis in conjunction with the rotation thereof, such as an inscribed planetary gear mechanism Alternatively, a cycloid reduction gear (speed increaser) or a trochoid reduction gear (speed increase) having various structures may be applied to at least one of the first and second transmission mechanisms of the present invention.
　また、前記実施形態では、バランスウェイトＷを第２伝動部材８の内部空間ＳＰに収容したものを示したが、バランスウェイトＷの配設部位は実施形態に限定されず、例えば、第２伝動部材８の外側等に配設してもよい。 In the above embodiment, the balance weight W is stored in the internal space SP of the second transmission member 8. However, the location of the balance weight W is not limited to the embodiment, and for example, the second transmission member. You may arrange | position on the outer side of 8 etc.
　また、前記実施形態では、第１，第２変速機構Ｔ１，Ｔ２の各伝動溝２１，２２；２４，２５をトロコイド曲線に沿った波形環状の波溝としているが、これら伝動溝は、実施形態に限定されるものでなく、例えばサイクロイド曲線に沿った波形環状の波溝としてもよい。 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.
　また、前記実施形態では、第１，第２変速機構Ｔ１，Ｔ２の第１及び第２伝動溝２１，２２間、並びに第３及び第４伝動溝２４，２５間にボール状の第１及び第２転動体２３，２６を介装したものを示したが、その転動体をローラ状又はピン状としてもよく、この場合に、第１及び第２伝動溝２１，２２、並びに第３及び第４伝動溝２４，２５は、ローラ状又はピン状の転動体が転動し得るような内側面形状に形成される。 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.
　また前記実施形態では、偏心回転部材６及び第３伝動部材９を、デフケースＣに支持される駆動車軸Ｓ１，Ｓ２に接続（スプライン嵌合）して、これら駆動車軸Ｓ１，Ｓ２を介してデフケースＣに支持させるようにしたものを示したが、本発明では、偏心回転部材６及び第３伝動部材９をデフケースＣに直接支持させるようにしてもよい。 In the above-described embodiment, the eccentric rotating member 6 and the third transmission member 9 are connected to the drive axles S1 and S2 supported by the differential case C (spline fitting), and the differential case C is connected via the drive axles S1 and S2. In the present invention, the eccentric rotating member 6 and the third transmission member 9 may be directly supported by the differential case C.
　また前記実施形態では、第１，第２転動ボール２３，２６を円滑に転動させるために第１，第２保持部材Ｈ１，Ｈ２を用いたものを示したが、第１，第２保持部材Ｈ１，Ｈ２無しでも第１，第２転動ボール２３，２６が円滑に転動可能な場合は、第１，第２保持部材Ｈ１，Ｈ２を省略してもよい。
  In the above embodiment, the first and second holding members H1 and H2 are used to smoothly roll the first and second rolling balls 23 and 26. If the first and second rolling balls 23 and 26 can smoothly roll without the members H1 and H2, the first and second holding members H1 and H2 may be omitted.

Claims (4)

  1. 　デフケース（Ｃ）と、このデフケース（Ｃ）内に収容された差動機構（３）とを備え、その差動機構（３）が、デフケース（Ｃ）に入力される回転トルクを、デフケース（Ｃ）に支持した一対のドライブ軸（Ｓ１，Ｓ２）に分配可能な差動装置であって、
    　前記デフケース（Ｃ）は、前記回転トルクを受けるヘリカルギヤよりなるリングギヤ（Ｃｇ）と、前記一対のドライブ軸（Ｓ１，Ｓ２）を支持するボス部（Ｂ）を内周端部に有し且つ外周端部が前記リングギヤ（Ｃｇ）の軸方向両端部にそれぞれ接合される一対の側壁板部（Ｃａ，Ｃｂ）とを備え、
    　前記両側壁板部（Ｃａ，Ｃｂ）は、その両者の外側面間の軸方向距離が径方向内方に向かうにつれて長くなると共に、各側壁板部（Ｃａ，Ｃｂ）の、径方向でリングギヤ（Ｃｇ）寄りの所定中間部（ｍ）から前記外周端部までの第１部分（ａ１）の肉厚が外周端部に近づくにつれて漸増し、
    　前記各側壁板部（Ｃａ，Ｃｂ）の前記第１部分（ａ１）の内側面が、前記リングギヤ（Ｃｇ）に向かって軸方向内方側に彎曲していることを特徴とする差動装置。     A differential case (C) and a differential mechanism (3) accommodated in the differential case (C) are provided, and the differential mechanism (3) generates rotational torque input to the differential case (C). ) That can be distributed to a pair of drive shafts (S1, S2) supported by
    The differential case (C) has a ring gear (Cg) made of a helical gear that receives the rotational torque, and a boss portion (B) that supports the pair of drive shafts (S1, S2) at an inner peripheral end, and an outer peripheral end. A pair of side wall plate portions (Ca, Cb) that are respectively joined to both axial ends of the ring gear (Cg),
    The both side wall plate portions (Ca, Cb) become longer as the axial distance between the outer side surfaces of the both side wall portions (Ca, Cb) increases inward in the radial direction, and the ring gear ( Cg) The thickness of the first portion (a1) from the predetermined intermediate portion (m) close to the outer peripheral end portion gradually increases as it approaches the outer peripheral end portion,
    The differential device characterized in that an inner surface of the first portion (a1) of each side wall plate portion (Ca, Cb) is bent inward in the axial direction toward the ring gear (Cg).
  2. 　前記各側壁板部（Ｃａ，Ｃｂ）の、前記所定中間部（ｍ）から前記ボス部（Ｂ）までの第２部分（ａ２）の肉厚がボス部（Ｂ）に近づくにつれて漸増していることを特徴とする、請求項１に記載の差動装置。 The thickness of the second portion (a2) from the predetermined intermediate portion (m) to the boss portion (B) of each side wall plate portion (Ca, Cb) gradually increases as it approaches the boss portion (B). The differential device according to claim 1, wherein:
  3. 　前記各側壁板部（Ｃａ，Ｃｂ）の外周端部と前記リングギヤ（Ｃｇ）との相互の接合面には段差（ｓ）を有することを特徴とする、請求項１又は２に記載の差動装置。 3. The differential according to claim 1, wherein a step (s) is provided at a joint surface between the outer peripheral end of each of the side wall plate portions (Ca, Cb) and the ring gear (Cg). apparatus.
  4. 　前記差動機構（３）は、前記両ボス部（Ｂ）の中心を通る第１軸線（Ｘ１）を中心軸線として一方の前記側壁板部（Ｃａ）に一体的に設けられた第１伝動部材（５）と、一方の前記ドライブ軸（Ｓ１）に接続されて前記第１軸線（Ｘ１）回りに回転可能な主軸部（６ｊ）、および前記第１軸線（Ｘ１）から偏心した第２軸線（Ｘ２）を中心軸線とする偏心軸部（６ｅ）が互いに一体に連結された偏心回転部材（６）と、前記第１伝動部材（５）に対向配置されて前記偏心軸部（６ｅ）に回転自在に支持される第２伝動部材（８）と、その第２伝動部材（８）に対向配置されると共に他方のドライブ軸（Ｓ２）に接続されて前記第１軸線（Ｘ１）回りに回転可能な第３伝動部材（９）と、前記第１及び第２伝動部材（５，８）間で変速しつつトルク伝達可能な第１変速機構（Ｔ１）と、前記第２及び第３伝動部材（８，９）間で変速しつつトルク伝達可能な第２変速機構（Ｔ２）とを備えており、
    　前記第１変速機構（Ｔ１）は、第１伝動部材（５）の、第２伝動部材（８）との対向面に在り且つ第１軸線（Ｘ１）を中心とする波形環状の第１伝動溝（２１）と、第２伝動部材（８）の、第１伝動部材（５）との対向面に在り且つ第２軸線（Ｘ２）を中心とする波形環状で波数が第１伝動溝（２１）とは異なる第２伝動溝（２２）と、第１及び第２伝動溝（２１，２２）の複数の交差部に介装され、第１及び第２伝動溝（２１，２２）を転動しながら第１及び第２伝動部材（５，８）間の変速伝動を行う複数の第１転動体（２３）とを有し、
    　前記第２変速機構（Ｔ２）は、第２伝動部材（８）の、第３伝動部材（９）との対向面に在り且つ第２軸線（Ｘ２）を中心とする波形環状の第３伝動溝（２４）と、第３伝動部材（９）の、第２伝動部材（８）との対向面に在り且つ第１軸線（Ｘ１）を中心とする波形環状で波数が第３伝動溝（２４）とは異なる第４伝動溝（２５）と、第３及び第４伝動溝（２４，２５）の複数の交差部に介装され、第３及び第４伝動溝（２４，２５）を転動しながら第２及び第３伝動部材（８，９）間の変速伝動を行う複数の第２転動体（２６）とを有し、
    　前記第１伝動溝（２１）の波数をＺ１、前記第２伝動溝（２２）の波数をＺ２、前記第３伝動溝（２４）の波数をＺ３、前記第４伝動溝（２５）の波数をＺ４としたとき、
    　次式　（Ｚ１／Ｚ２）×（Ｚ３／Ｚ４）＝２
    が成立することを特徴とする、請求項１～３の何れかに記載の差動装置。
          The differential mechanism (3) is a first transmission member provided integrally with the one side wall plate (Ca) with a first axis (X1) passing through the centers of the bosses (B) as a central axis. (5), a main shaft portion (6j) that is connected to one of the drive shafts (S1) and is rotatable about the first axis (X1), and a second axis that is eccentric from the first axis (X1) ( An eccentric shaft member (6e) whose central axis is X2) is connected to the eccentric rotating member (6) integrally connected to each other and the first transmission member (5) so as to rotate to the eccentric shaft portion (6e). A second transmission member (8) that is freely supported, and disposed opposite to the second transmission member (8) and connected to the other drive shaft (S2) and rotatable about the first axis (X1). The third transmission member (9) and the first and second transmission members (5, 8) First transmission mechanism Phrases can transmit and (T1), and a second transmission mechanism capable torque transmission (T2) while shifting between said 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 corrugated annular first transmission groove centered on the first axis (X1). (21) and the second transmission member (8) on the surface facing the first transmission member (5) and having a corrugated annular shape centered on the second axis (X2) and having a wave number of the first transmission groove (21) Different from the second transmission groove (22) and a plurality of intersecting portions of the first and second transmission grooves (21, 22), rolling the first and second transmission grooves (21, 22). While having a plurality of first rolling elements (23) for performing transmission transmission between the first and second transmission members (5, 8),
    The second transmission mechanism (T2) is located on the surface of the second transmission member (8) facing the third transmission member (9) and has a wave-shaped third transmission groove centered on the second axis (X2). (24) and the third transmission member (9) on the surface facing the second transmission member (8) and having a wave shape centered on the first axis (X1) and having a wave number of the third transmission groove (24) Different from the fourth transmission groove (25) and a plurality of intersections of the third and fourth transmission grooves (24, 25), and rolls on the third and fourth transmission grooves (24, 25). A plurality of second rolling elements (26) for performing transmission transmission between the second and third transmission members (8, 9),
    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 When Z4
    The following formula (Z1 / Z2) × (Z3 / Z4) = 2
    The differential device according to any one of claims 1 to 3, wherein:
PCT/JP2016/083962 2015-11-17 2016-11-16 Differential device WO2017086344A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61192949A (en) * 1985-02-19 1986-08-27 Honda Motor Co Ltd Planet gear type differential gears
JPH09144852A (en) * 1995-11-22 1997-06-03 Kenji Mimura Differential device
US20100056320A1 (en) * 2008-09-04 2010-03-04 Ziech James F Spider-less vehicle differential

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61192949A (en) * 1985-02-19 1986-08-27 Honda Motor Co Ltd Planet gear type differential gears
JPH09144852A (en) * 1995-11-22 1997-06-03 Kenji Mimura Differential device
US20100056320A1 (en) * 2008-09-04 2010-03-04 Ziech James F Spider-less vehicle differential

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