JP2018096502A - Differential device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an assembling workability at a differential device when an output shaft having an elastic engagement member engaged in advance is fitted and inserted into an output gear.SOLUTION: An output gear 30 comprises: a thrust supported surface 101; a first elastic member receiving surface 201 adjacent to a radial direction inner side of the output gear at the thrust supported surface; and a first inner end surface 301 of the first elastic member receiving surface, adjacent to a radial direction inner side of the output gear 30. An input member 10 has: a thrust supporting surface 102 supporting the supported surface directly or through a washer 34; a second elastic member receiving surface 202 of the thrust supporting surface opposing against between it and the first elastic member receiving surface adjacent to a radial direction inner side of the output gear while holding an elastic member 50; and a second inner end surface 302 adjacent to a radial direction inner side of the output gear of the second elastic member receiving surface and opposing to the first inner end surface while holding a clearance 500. A releasing end 500e at a radial direction inner side of the output gear of the clearance is formed to have a smaller width w than a thickness t of an elastic engagement member 41.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a differential device suitable for a vehicle such as an automobile.

  Conventionally, as a differential device, a pair of side gears (output gears) facing each other, a differential case (input member) covering the back of the pair of side gears, and a plurality of gears that are rotatably supported by the differential case and mesh with the pair of side gears, respectively. Pinion gears (differential gears), side gear washers (output gear washers) interposed between the spherically curved back surface of each side gear and the spherically curved inner surface of the differential case, and each side gear on the pinion gear side For example, Patent Document 1 discloses a spring (elastic member) that biases each of the side gear and the side gear and the pinion gear with each other without rattling by the biasing force of the spring.

  In addition, a differential device in which a side gear washer and a spring are arranged in parallel in the radial direction of the side gear between the inner surface of the differential case and the back surface of the side gear has already been proposed (see, for example, Patent Document 2).

  Further, in a differential device in which a drive shaft (output shaft) is inserted into the center hole of the side gear so as not to be relatively rotatable, a snap ring (elastic locking member) interposed between the fitting surfaces of the side gear and the drive shaft is used. A technique for preventing the drive shaft from coming off from the side gear is also known (see, for example, Patent Document 3).

JP 2009-198003 A Japanese Utility Model Publication No. 58-165359 JP 2008-223835 A

  In the differential device combining the techniques of Patent Documents 1 to 3, a spring is installed between the opposing surfaces of the inner surface of the differential case and the back surface of the side gear, particularly between the opposing surfaces on the radially inner side of the side gear from the side gear washer. It is the arrangement in which the space to be provided is provided.

  However, in the above arrangement, when the drive shaft is fitted into the center hole of the side gear and assembled, the snap ring previously locked to the outer periphery of the tip end portion of the drive shaft passes through the side of the space. There is a case where the diameter is expanded and the inner wall or the spring forming the space is strongly contacted. In that case, in order to allow the snap ring to ride over (i.e., pass through) the inner wall or spring forming the space against the strong contact resistance received from the inner wall or spring forming the space, It is necessary to increase the insertion load, and the assembly workability of the differential device may be deteriorated.

  An object of this invention is to provide the differential device which can solve the said subject.

  In order to achieve the above object, a differential device according to the present invention includes a pair of output gears each having a center hole, opposite input gears covering the back surfaces of the pair of output gears, and the input members. A plurality of differential gears that are rotatably supported by the pair of output gears, and outer peripheral surfaces of the pair of output shafts that are inserted into the center holes of the pair of output gears so as not to rotate relative to each other. A pair of elastic locking members interposed between the center hole and preventing the pair of output shafts from coming off from the pair of output gears, respectively, between the output gear and the input member; And a pair of elastic members that respectively bias the pair of output gears toward the differential gear in the axial direction of the output gear, and each of the output gears includes the input gear of the output gear. Acts on the output gear on the back facing the member A thrust supported surface that transmits at least a portion of the thrust to the input member, a first elastic member receiving surface adjacent to the radially inner side of the output gear of the thrust supported surface, and the first A first inner end surface of the elastic member receiving surface adjacent to the radially inner side of the output gear, and the input member has an inner surface facing the back surface of the input member, A thrust support surface that rotatably supports a thrust supported surface directly or via an output gear washer; the thrust support surface adjacent to the radially inner side of the output gear and sandwiching the elastic member; A second elastic member receiving surface facing the elastic member receiving surface, and the second elastic member receiving surface adjacent to the radially inner side of the output gear and with respect to the first inner end surface. The second facing the gap in the axial direction of the output gear Has an inner end surface, a of the gap, radially inner side of the open end of said output gear is formed smaller width than the thickness of the elastic locking member in the axial direction of the output gear.

  Preferably, at least one inner end surface of the first and second inner end surfaces is more than the elastic member receiving surface adjacent to the at least one inner end surface in the radial direction of the output gear. Projecting in the axial direction of the output gear.

  Further preferably, the input member has a support hole that rotatably fits and supports the outer peripheral surface of the output shaft, and the output shaft can be inserted into the center hole of the output gear through the support hole. The inner diameter of the end portion of the support hole on the output gear side is smaller than the inner diameter of the end portion of the center hole on the outer side in the axial direction of the output gear.

  According to the present invention, it is possible to avoid deterioration in workability of assembling the differential device.

The schematic diagram of the principal part longitudinal cross-section of the transmission including the differential gear which concerns on 1st Embodiment of this invention. A2 enlarged sectional view of FIG. It is a schematic diagram (corresponding to FIG. 2) of an enlarged cross section for explaining the process of inserting and assembling the drive shaft into the side gear, (a) showing the initial stage of insertion, and (b) showing the snap ring on the side gear side. Shows the intermediate stage of sliding on the spline teeth Schematic diagram of the cross section of the relevant part showing the second embodiment of the present invention (corresponding to FIG. 2)

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

  First, in FIGS. 1 to 3 showing the first embodiment, a differential device D is housed in a transmission case 3 of an automobile together with a transmission (not shown). The differential device D includes, for example, a differential case 10 made of a seamless single member and having a first axis X1 as a rotation axis, and the differential gear mechanism 1 incorporated in the differential case 10.

  The differential case 10 includes, for example, a pair of cylindrical main bodies 11 that can accommodate the differential gear mechanism 1 and a pair of cylindrical bodies that project integrally from both side walls of the case main body 11 in the direction along the first axis X1. Bosses 10b and 10b '. Further, the pair of boss portions 10b and 10b ′ are arranged on the first axis X1 at intervals. The differential case 10 is rotatably supported by the transmission case 3 via bearings 2 and 2 'at the boss portions 10b and 10b'. The inner peripheral surfaces of the boss portions 10b and 10b 'constitute support holes 5 and 5' for fitting and supporting a pair of drive shafts 40 described later rotatably.

  In addition, an annular flange 6 is integrally formed in a part of the case body 11 so as to be offset from the center C of the differential case 10 to one side in the axial direction of the side gear 30 described later. A ring gear 8 that meshes with the drive gear 7 of the transmission connected to the power source is fixed to the flange 6 with appropriate fixing means (for example, a bolt 9 in this embodiment). A ring gear may be formed integrally with the differential case 10.

  The differential gear mechanism 1 includes, for example, a pinion shaft 21 that is on the second axis X2 orthogonal to the first axis X1 and is held by the differential case 10 so as to pass through the center C of the differential case 10, and both ends of the pinion shaft 21 And a pair of pinion gears 20 that are fitted and supported so as to be rotatable about the second axis X2, and are arranged so that each pinion gear 20 is sandwiched between them in the direction along the first axis X1. And a pair of side gears 30 that mesh with 20. In the present embodiment, the differential case 10 is an example of an input member, the pinion gear 20 is an example of a differential gear, the side gear 30 is an example of an output gear, and the drive shaft 40 is an example of an output shaft. The inner surface 10f of the differential case 10 is formed in a spherical shape equidistant from the center C, for example.

  The pinion gear 20 has, for example, a pinion center hole into which the pinion shaft 21 can be inserted. In the present embodiment, the pinion gears 20 are each constituted by a bevel gear, and are incorporated (accommodated) in the differential case 10 together with the pinion shaft 21.

  Further, the back surface of the pinion gear 20 is formed in a spherical shape in accordance with the spherical inner surface 10f of the differential case 10 and an annular curved surface around the second axis X2. A spherical pinion gear washer 24 is interposed between the opposing surfaces of the back surface of the pinion gear 20 and the inner surface 10f of the differential case 10.

  A pair of shallow recesses 21 a that form an oil passage between the inner surface of the center hole of the pinion gear 20 are provided on the outer peripheral surfaces of both ends of the pinion shaft 21. The pinion shaft 21 is fixed to the differential case 10 by press-fitting a retaining pin 23 that passes through the pinion shaft 21 into the differential case 10. As a means for fixing the retaining pin 23 to the differential case 10, fixing means other than press fitting (for example, welding, screwing, etc.) can be employed.

  The pair of side gears 30 are each constituted by a bevel gear in the present embodiment, and are incorporated (accommodated) in the differential case 10 in the same manner as the pinion gear 20.

  Each side gear 30 integrally includes a hub portion 30 h and a tooth portion 30 g that is located on the radially outer side of the hub portion 30 h in the side gear 30 and meshes with the pinion gear 20. A central hole 30ha that penetrates the hub portion 30h in the axial direction is formed at the center portion of the hub portion 30h. Spline teeth 32 are formed at the axial center of the side gear 30 of the center hole 30ha. The spline teeth 32 are fitted to the spline teeth 42 provided on the outer periphery of the front end portion of the drive shaft 40 so as to be slidable in the axial direction of the side gear 30 and not relatively rotatable. Thereby, the pair of side gears 30 are coupled so as to be able to rotate integrally with the tip portions of the pair of drive shafts 40 fitted into the support holes 5, 5 ′ of the differential case 10.

  Thus, the rotational driving force input from the power source to the differential case 10 via the transmission is transmitted to the pair of side gears 30 and further to the pair of drive shafts 40 via the pinion shaft 21 and each pinion gear 20. As a result, the pair of drive shafts 40 are rotationally driven while allowing differential rotation.

  The inner diameter d2 of at least the axially outward end of the side hole 30 of the center hole 30ha of the side gear 30 is the end of the support hole 5, 5 'of the differential case 10 on the side gear 30 side as illustrated in FIG. The diameter is set larger than the inner diameter d1 of the part (that is, d2> d1).

  A snap ring 41 as an elastic locking member for preventing the drive shaft 40 from coming off with respect to the side gear 30 is interposed between the outer periphery of the front end portion of each drive shaft 40 and the corresponding center hole 30ha. The

  The snap ring 41 is made of, for example, a C-shaped elastic material, and has elasticity that expands more than the inner diameter of the center hole 30ha (and hence the minimum inner diameter of the spline teeth 32) in a free state.

  Further, the snap ring 41 has, for example, an inner peripheral end engaged with an annular groove 40 a provided on the outer periphery of the tip end of the drive shaft 40, and an outer peripheral end of the spline teeth 32 of the side gear 30. Engage with the inner end in the direction. Therefore, when the snap ring 41 is set on the side gear 30 together with the drive shaft 40, the snap ring 41 is pressed against the inner periphery of the center hole 30ha by its own elastic force, and the drive shaft 40 is prevented from coming off from the side gear 30. Has the function of retaining. That is, the snap ring 41 has a function of preventing the drive shaft 40 from coming off from the side gear 30.

  Of the rear surface 30f of the side gear 30 (that is, the outer surface of the side gear 30 opposite to the tooth surface of the tooth portion 30g in the axial direction of the side gear 30), for example, The first curved surface 101 is formed in a spherical shape around the first axis X1 in conformity with the spherical inner surface 10f of the differential case 10. Between the first curved surface 101 and the inner surface 10f of the differential case 10 facing the first curved surface 101 (that is, the second curved surface 102), relative rotation and thrust transmission are allowed. A spherical and annular side gear washer 34 is interposed. As a variation of the present embodiment, the side gear washer 34 may be omitted and the first and second curved surfaces 101 and 102 may be directly brought into contact with each other so as to be slidable.

  Thus, the first curved surface 101 is an example of a supported surface (that is, a thrust supported surface) in the side gear 30 of the thrust transmitted from the side gear 30 to the differential case 10, and the second curved surface 102 is the side gear. 3 is an example of a thrust support surface in the differential case 10 that receives the thrust transmitted from 30 to the differential case 10. The pinion gear washer 24 is an example of a differential gear washer, and the side gear washer 34 is an example of an output gear washer.

  The back surface 30f of the side gear 30 has a short cylindrical shape that is adjacent to the radially inward side of the first curved surface 101 in the side gear 30 and protrudes outward in the axial direction of the side gear 30 from the first curved surface 101. A shaft portion 30j is formed. An annular recess 10fa that receives the shaft portion 30j is formed on the inner surface 10f of the differential case 10 so as to surround the support holes 5 and 5 '.

  Further, the shaft portion 30j is recessed by one step from the end surface of the shaft portion 30j on the radially inner side of the side gear 30 to the radially inner side of the side gear 30 on the radially outer side of the shaft portion 30j. An annular recess 30ja is formed. The bottom surface of the recess 30ja (that is, the end surface in the axial direction of the side gear 30) is a first spring receiving surface (adjacent to the first curved surface 101 on the radially inward side of the side gear 30 via an annular step surface). 1st elastic member receiving surface) 201 is comprised.

  The end portion of the shaft portion 30j on the radially inward side of the side gear 30 is adjacent to the radially inward side of the side spring 30 of the first spring receiving surface 201 via an annular step surface and A first inward end surface 301 that protrudes in the axial direction of the side gear 30 from the spring receiving surface 201 is configured. The first spring receiving surface 201 and the first inner end surface 301 are both flat surfaces orthogonal to the first axis X1 in this embodiment.

  On the other hand, the first spring receiving surface 201 on the bottom surface of the annular recess 10fa on the inner surface 10f of the differential case 10 (that is, the end surface of the recess 10fa in the axial direction of the side gear 30) faces the first spring receiving surface 201 across the annular space 400. The bottom surface portion of the second spring 102 constitutes a second spring receiving surface (second elastic member receiving surface) 202 adjacent to the second curved surface 102 on the radially inward side of the side gear 30 via an annular step surface. . The second bottom surface portion of the bottom surface of the annular recess 10fa facing the first inner end surface 301 is a second adjacent to the radially inner side of the side gear 30 of the second spring receiving surface 202. An inner end surface 302 is formed.

  In this embodiment, the second spring receiving surface 202 and the second inner end surface 302 are both flat surfaces orthogonal to the first axis X1 and are flush with each other. Note that the second spring receiving surface 202 and the second inner end surface 302 do not necessarily have to be flush with each other, and for example, a slight level difference may be provided between them.

  Further, in the present embodiment, a chamfered portion 302 c that gradually increases the diameter of the opening edge of the support holes 5, 5 ′ of the differential case 10 is provided at the inner peripheral end portion of the second inner end surface 302. The outer peripheral edge of the chamfered portion 302c is located outward by a predetermined distance s in the radial direction of the side gear 30 from the opening edge of the center hole 30ha of the side gear 30 on the axially outward side (left side in FIG. 2). Located in. Thereby, when pulling out the drive shaft 40 from the side gear 30 as described later, the snap ring 41 is guided while sliding on the chamfered portion 302c, and can be smoothly inserted into the support holes 5 and 5 '. If necessary, a modified example in which the chamfered portion 302c is omitted or a modified example in which the chamfered portion 302c is formed to be narrower than that in the embodiment (all modified examples are not shown) can be implemented.

  An annular gap 500 having a width w smaller than the width of the space 400 in the axial direction of the side gear 30 is interposed between the opposing surfaces of the first and second inner end surfaces 301 and 302. Then, an open end on the radially inner side of the side gear 30 (a radially inner end of the side gear 30) 500e of the gap 500 sandwiched between the first and second inner end surfaces 301 and 302 in the axial direction of the side gear 30. Is formed with a width w smaller than the thickness t of the snap ring 41 in the axial direction of the side gear 30.

  Thus, in the present embodiment in which the chamfered portion 302 c is provided on the second inner end surface 302, the width w of the open end 500 e is such that the first inner end surface 301 is radially inward of the side gear 30. This corresponds to the mutual distance in the axial direction of the side gear 30 between the end portion and the outer peripheral portion of the chamfered portion 302c facing the end portion (see the partially enlarged view of FIG. 2). In a modification (not shown) in which the chamfered portion 302c is omitted, the width w of the open end 500e is equal to the mutual distance between the first and second inner end surfaces 301 and 302 in the side gear 30 in the axial direction.

  In the space 400 between the opposing surfaces of the first and second spring receiving surfaces 201 and 202, that is, in the space 400, a spring 50 that elastically urges and urges the side gear 30 toward the pinion gear 20 in the axial direction of the side gear 30 is disposed. The And between the one end part and the other end part of the spring 50 in the axial direction of the side gear 30 and the first and second spring receiving surfaces 201 and 202, respectively, based on the elastic force of the spring 50, each is moderate. It is connected so as to be able to rotate and slide by frictional force. As a result, the occurrence of rattling (sounding noise) at the mutual meshing part of the side gear 30 and the pinion gear 20 and the mutual spline engaging part of the side gear 30 and the drive shaft 40 is suppressed.

  The spring 50 may be of any type and material as long as it is a spring member that is disposed in the space 400 and is sandwiched between the first and second spring receiving surfaces 201 and 202 and can exhibit the desired elasticity. It can be used. For example, the spring 50 can be appropriately selected from various spring members such as a disc spring, a corrugated spring that is curved in a circumferential direction, and a coil spring. The spring 50 is an example of an elastic member.

  Further, the front end portions of the pair of drive shafts 40 are inserted into the center holes 30ha of the pair of side gears 30 from the outer sides in the axial direction of the side gears 30 through the support holes 5 and 5 'of the differential case 10, respectively. The spline teeth 32 of the center hole 32ha and the spline teeth 42 on the outer periphery of the tip of the drive shaft 40 are spline-fitted. As a result, the side gear 30 and the drive shaft 40 rotate integrally around each other around the first axis X1. Further, the outer end side of the drive shaft 40 in the axial direction of the side gear 30 is interlocked and connected to left and right axles (not shown) outside the differential case 10.

  At least one of the fitting surfaces of the inner peripheral surface of the support holes 5 and 5 ′ of the differential case 10 and the outer peripheral surface of the tip of the drive shaft 40 (in this embodiment, the inner peripheral surface of the support holes 5 and 5 ′) Spiral grooves 5s and 5s' are formed. The spiral grooves 5s and 5s 'exhibit a screw pump action in accordance with the relative rotation between the inner peripheral surface of the support holes 5 and 5' and the outer peripheral surface of the tip of the drive shaft 40 when the automobile is traveling forward. The lubricating oil in the case 3 can be drawn into the differential case 10. Then, the drawn lubricating oil is used for the lubricated portion in the differential case 10, for example, between the back surface 30f of the side gear 30 and the inner surface 10f of the differential case 10, the spline engaging portion between the side gear 30 and the drive shaft 40, the side gear 30 and the pinion gear. 20 can be supplied to the meshing part with the joint 20 or the like.

  A pair of work windows (not shown) are provided on the peripheral wall of the differential case 10 symmetrically on both sides of the center C across the center C of the differential case 10. The pair of work windows are, for example, a work for processing the inner surface 10f of the differential case 10 into a spherical shape, and each component of the differential gear mechanism 1 (more specifically, the pinion gear 20, the side gear 30, the pinion gear washer 24, the side gear washer 34). Etc.) is allowed to be inserted into the differential case 10 and assembled. Further, the lubricating oil in the mission case 3 can be introduced into the differential case 10 through a pair of work windows.

  Next, the operation of the first embodiment will be described with reference to FIG. In assembling the differential device D, first, the side gear 30 and the pinion gear 20, and the pinion gear washer 24 and the side gear washer 34 are inserted into the differential case 10 through a work window (not shown), and the side gear 30 and the pinion gear 20 and the pinion gear washer 24 are inserted. The side gear washer 34 is set at a predetermined assembly position in the differential case 10. From this state, the pinion shaft 21 is inserted from the outside of the differential case 10 into the pinion shaft support hole of the differential case 10 and the center hole of the pinion gear 20. Next, the pinion shaft 21 is fixed to the differential case 10 with a retaining pin (pin) 23.

  The differential case 10 of the differential device D thus assembled is attached to the transmission case 3 via the bearings 2 and 2 '. Thereby, the differential case 10 of the differential device D is rotatably supported by the mission case 3. Next, the pair of drive shafts 40 are spline-fitted to the center holes 32ha of the pair of side gears 30 through the through holes (not shown) of the transmission case 3 and the support holes 5 and 5 'of the differential case 10, respectively.

  At this time, the snap ring 41 is temporarily assembled on the outer periphery of the tip end portion of each drive shaft 40 (more specifically, the inner peripheral end portion of the snap ring 41 is inserted into the annular groove 40a of the drive shaft 40 in advance. Fit and lock). Therefore, in the process of spline fitting the tip end portion of the drive shaft 40 to the center hole 32ha of the side gear 30 through the support holes 5 and 5 'of the differential case 10, the snap ring 41 temporarily assembled to the drive shaft 40 is self-expanding. In a state where the diameter is reduced against the radial force, the inner surfaces of the support holes 5 and 5 'and the spline teeth 32 of the center hole 32ha are sequentially slid (see FIGS. 3A and 3B). .

  Then, after passing through the peak portion of the spline teeth 32 of the center hole 32ha, the snap ring 41 is expanded and deformed by its own elastic expansion force, and the spline teeth 32 are formed on the inner end of the side gear 30 in the axial direction. Engagement is automatically possible (see FIGS. 1 and 2). Thus, the drive shaft 40 is prevented from coming off from the side gear 30 by the snap ring 41.

  When removing the drive shaft 40 from the differential device D for maintenance or the like, a large pulling force greater than a predetermined value is applied to the drive shaft 40. Then, the snap ring 41 on the outer periphery of the tip end portion of the drive shaft 40 can be deformed to reduce its diameter against its own elastic expansion force, and can get over the peak portion of the spline teeth 32. Thereby, the drive shaft 40 can be pulled out, and the drive shaft 40 can be detached from the differential device D.

  In the present embodiment, the back surface 30f of each side gear 30 includes a first curved surface 101 serving as a thrust supported surface that transmits at least a part of the thrust acting on each side gear 30 to the differential case 10, and a first curved surface. A first spring receiving surface 201 adjacent to the surface 101 on the radially inner side of the side gear 30 and a first inner end surface of the first spring receiving surface 201 adjacent to the radially inner side of the side gear 30. 301. On the other hand, the differential case 10 has a second curved surface 102 that functions as a thrust support surface that supports the first curved surface 101 directly or via the side gear washer 34 on the inner surface 10f facing the back surface 30f of the side gear 30; A second spring receiving surface 202 that sandwiches the spring 50 between the second curved surface 102 and the first spring receiving surface 201 adjacent to the radially inward side of the side gear 30. A second inner end face 302 that is adjacent to the radially inner side of the side gear 30 and faces the first inner end face 301 with the gap 500 interposed therebetween in the axial direction of the side gear 30. . An open end 500 e on the radially inner side of the side gear 30 in the gap 500 is formed with a width w smaller than the thickness t of the snap ring 41 in the axial direction of the side gear 30.

  Therefore, according to the dimensional relationship (w <t) between the gap 500 (more specifically, the open end 500e) and the snap ring 41, the drive shaft 40 is assembled by being inserted into the center hole 30ha of the side gear 30. In addition, even when the snap ring 41 previously locked to the drive shaft 40 passes through the side of the space 400, there is no possibility that the diameter of the snap ring 41 expands by its own elasticity and is pressed against and interferes with the inner wall of the space 400 and the spring 50. . This eliminates the need for specially increasing the insertion load of the drive shaft 40 in order for the snap ring 41 to pass through the side of the space 400. Therefore, the deterioration of the assembly workability of the differential device D (more specifically, the deterioration of the assembly workability due to the increase of the insertion load) is avoided.

  In addition, one of the first and second inner end surfaces 301 and 302 has an inner end surface (the first inner end surface 301 in the first embodiment) and the one inner end surface 301 and the side gear 30. It protrudes in the axial direction of the side gear 30 from the spring receiving surface 201 adjacent in the radial direction. Therefore, the step surface (more specifically, the inner peripheral surface of the recess 30ja) generated between the inner end surface 301 and the first spring receiving surface 201 temporarily causes the spring 50 to be temporarily attached during the assembly process of the differential device D. It can be used as a spring holding surface (elastic member holding surface) that can be temporarily fixed. Thereby, the assembly workability is improved.

  Further, in the present embodiment, the inner diameter d1 of the end portion on the side gear 30 side of the support holes 5 and 5 ′ is set smaller than the inner diameter d2 of the end portion on the axially outer side in the side gear 30 of the center hole 30ha of the side gear 30. Has been. As a result, the process of inserting the drive shaft 40 into the center hole 30ha of the side gear 30 through the support holes 5 and 5 'of the differential case 10, particularly when the snap ring 41 moves from the support holes 5 and 5' to the center hole 30ha ( 3A), the snap ring 41 can be effectively prevented from being caught by the opening edge of the center hole 30ha. Therefore, the operation of inserting the drive shaft 40 into the side gear 30 can be performed more smoothly.

  In the present embodiment, the first curved surface 101 that is the thrust supported surface of the side gear 30 and the second curved surface 102 that is the thrust supported surface of the differential case 10 are slidable through the side gear washer 34. Although supported, the elastic force of the spring 50 is directly transmitted to the rear surface 30f side of the side gear 30 via the first spring receiving surface 201 (that is, the rear surface of the side gear 30 without the side gear washer 34). The structure is directly transmitted to the 30f side). Accordingly, the surface pressure distribution of the rotational sliding portion between the side gear washer 34 and the side gear 30 is biased, causing uneven wear on the contact surface between the side gear washer 34 and the side gear 30 or seizure of the side gear washer 34 of the side gear 30. It can be prevented before it becomes a cause. In addition, there is no possibility that the effective area of the second curved surface 102 that is the thrust support surface is reduced due to the support of the side gear washer 34.

  Furthermore, in the present embodiment, since the first and second spring receiving surfaces 201 and 202 are configured as flat surfaces orthogonal to the first axis X1, the set load of the spring 50 is applied to each spring receiving surface 201 and 202. However, it can be transmitted efficiently.

  Next, a second embodiment of the present invention will be described with reference to FIG. In the first embodiment described above, on the back surface 30f of the side gear 30, the first inner end surface 301 of the first spring receiving surface 201 adjacent to the radially inner side of the side gear 30 is the first spring receiving surface. By projecting in the axial direction of the side gear 30 rather than 201, the axial gap 500 in the side gear 30 between the first and second inner end surfaces 301 and 302 (more specifically, the radially inward in the side gear 30). The opening end 500e) on the side is formed such that the snap ring 41 has a width w smaller than the axial thickness t of the side gear 30. In contrast, in the second embodiment, the first inner end surface 301 and the first spring receiving surface 201 are flat surfaces that are flush with each other (more specifically, perpendicular to the first axis X1). And the second inner end surface 302 of the second spring receiving surface 202 adjacent to the radially inner side of the side gear 30 protrudes in the axial direction of the side gear 30 from the second spring receiving surface 202. Let's make it. As a result, the axial gap 500 in the side gear 30 (more specifically, the radially inner opening end 500e in the side gear 30) between the first and second inner end surfaces 301 and 302 is snap-ringed. 41 is formed to have a width w smaller than the axial thickness t of the side gear 30.

  Other configurations of the second embodiment are the same as those of the first embodiment. Therefore, the constituent elements of the second embodiment are given the same reference numerals as the corresponding constituent elements of the first embodiment, and further description thereof is omitted.

  Thus, also in the second embodiment, it is possible to achieve basically the same functions and effects as those of the first embodiment.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, A various design change is possible in the range which does not deviate from the summary.

  For example, in the first and second embodiments, the differential device D is accommodated in the vehicle mission case 3, but the differential device D is not limited to the differential device for vehicles, It can be implemented as a differential for a mechanical device. In the first and second embodiments, the differential device D is applied to the left and right wheel transmission system to distribute power while allowing differential rotation with respect to the left and right drive shafts (output shafts). However, the present invention is not limited to this. In the present invention, for example, the differential device is applied to a front / rear wheel transmission system in a front / rear wheel drive vehicle so that power is distributed while allowing differential rotation to the front and rear propeller shafts (output shafts). May be.

  In the first and second embodiments, the pair of pinion gears 20 can be rotated to the differential case 10 via a single pinion shaft 21 that is formed separately from the pinion gear 20 and extends on one diameter line of the differential case 10. Although what was supported was shown, this invention is not restricted to this. In the present invention, for example, three or more pinion gears 20 may be rotatably supported on the differential case via three or more pinion shafts extending radially from the central portion of the differential case.

  In the first and second embodiments, an integrated differential case made of a single member without a joint is used as the differential case 10, but the present invention is not limited to this. In the present invention, for example, an integrated differential case in which a plurality of case elements that divide the differential case are combined and integrated so as not to be separated by connecting means such as welding may be used, or a differential case may be used. A differential case may be used in which a plurality of case elements to be divided are detachably coupled by fastening means such as bolts.

  Moreover, although what comprised the pinion gear 20 and the side gear 30 from the bevel gear was shown in 1st, 2nd embodiment, this invention is not limited to this. In the present invention, the pinion gear 20 and the side gear 30 may be replaced with bevel gears, and other gears may be employed. For example, the side gear 30 may be a face gear and the pinion gear 20 may be a spur gear or a bevel gear.

  In the first and second embodiments, the first and second spring receiving surfaces 201 and 202 that support the terminal portion of the spring 50 are flat surfaces orthogonal to the rotation axis (first axis X1) of the side gear 30. Although shown, the present invention is not limited to this. In the present invention, depending on the structure of the spring 50 and the form of the terminal portion, at least one of the spring receiving surfaces 201 and 202 may be a tapered surface or a curved surface.

  In the first and second embodiments, one of the inner end surfaces 301 (or 302) of the first and second inner end surfaces 301 and 302 is replaced with one of the inner end surfaces 301 (or 302). ) And the spring receiving surface (elastic member receiving surface) 201 (or 202) adjacent in the radial direction of the side gear 30 is illustrated as being protruded in the axial direction of the side gear 30, but the present invention is not limited to this. In the present invention, for example, both the first and second inner end surfaces 301 and 302 are projected in the axial direction of the side gear 30 rather than the spring receiving surfaces 201 and 202 adjacent in the radial direction of the side gear 30. May be.

  In the first and second embodiments, the axial distance between the first and second inner end surfaces 301 and 302 in the side gear 30 is set to be uniform in each region in a region other than the region of the chamfered portion 302c ( That is, the first and second inner end surfaces 301 and 302 are parallel to each other), but the present invention is not limited to this. In the present invention, the axial distance between the first and second inner end surfaces 301 and 302 in the side gear 30 is not uniform even in the region other than the region of the chamfered portion 302c (for example, the first and second surfaces). The inner end surfaces 301 and 302 are non-parallel).

D ... Differential device d1, d2 ... Inner diameter t ... Thickness w ... Width 5,5 '... Support hole 10 ... ... Differential case (input member)
10f: inner surface of differential case (input member) 20 ... pinion gear (differential gear)
30 ・ ・ ・ ・ ・ ・ Side gear (output gear)
30f: Back side of side gear (output gear) 30ha ... Center hole of side gear (output gear) 34 ... Side gear washer (output gear washer)
40 ・ ・ ・ ・ ・ ・ Drive shaft (output shaft)
41 ・ ・ ・ ・ ・ ・ Snap ring (elastic locking member)
50 ・ ・ ・ ・ ・ ・ Spring (elastic member)
101... First curved surface (supported surface)
102... Second curved surface (thrust support surface)
201, 202 ... first and second spring receiving surfaces (first and second elastic member receiving surfaces)
301, 302... First and second inner end surfaces 500... Gaps 500 e.

Claims (3)

A pair of opposed output gears (30) each having a central hole (30ha);
An input member (10) covering the back surface (30f) of the pair of output gears (30);
A plurality of differential gears (20) rotatably supported by the input member (10) and respectively meshed with the pair of output gears (30);
Interposed between the outer peripheral surface of the pair of output shafts (40) and the center hole (30ha), which are respectively inserted in the center holes (30ha) of the pair of output gears (30) so as not to be relatively rotatable. A pair of elastic locking members (41) for preventing the pair of output shafts (40) from coming off from the pair of output gears (30);
Each is disposed between the output gear (30) and the input member (10), and the pair of output gears (30) are arranged on the differential gear (20) side in the axial direction of the output gear (30). A pair of elastic members (50) that respectively bias the
Each of the output gears (30) receives at least a part of the thrust acting on the output gear (30) on the back surface (30f) of the output gear (30) facing the input member (10). A thrust supported surface (101) for transmitting to the member (10), and a first elastic member receiving surface (201) adjacent to the radially inner side of the output gear (30) of the thrust supported surface (101). And a first inner end surface (301) of the first elastic member receiving surface (201) adjacent to the radially inner side of the output gear (30),
The input member (10) rotates the thrust supported surface (101) directly or via an output gear washer (34) on the inner surface (10f) of the input member (10) facing the back surface (30f). A thrust support surface (102) that is freely supported, and the thrust support surface (102) adjacent to the radially inner side of the output gear (30) and sandwiching the elastic member (50), the first The second elastic member receiving surface (202) facing the elastic member receiving surface (201) and the second elastic member receiving surface (202) are adjacent to the radially inner side of the output gear (30). And a second inner end face (302) opposed to the first inner end face (301) with a gap (500) in the axial direction of the output gear (30).
The open end (500e) of the gap (500) on the radially inner side of the output gear (30) is the thickness (t) of the elastic locking member (41) in the axial direction of the output gear (30). A differential device formed to have a smaller width (w).   At least one inner end surface (301, 302) of the first and second inner end surfaces (301, 302) is connected to the at least one inner end surface (301, 302) and the output gear (30). 2. The differential device according to claim 1, wherein the differential member projects in the axial direction of the output gear (30) from the elastic member receiving surface (201, 202) adjacent in the radial direction. The input member (10) has a support hole (5, 5 ') that rotatably supports the outer peripheral surface of the output shaft (40), and the output shaft (40) is supported by the support hole ( 5, 5 ') can be inserted into the central hole (30ha) of the output gear (30),
The inner diameter (d1) of the end portion of the support hole (5, 5 ') on the output gear (30) side is the end of the center hole (30ha) on the axially outer side of the output gear (30). The differential device according to claim 1 or 2, wherein the differential device is smaller than an inner diameter (d2) of the portion.

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