JP4828847B2 - Differential equipment - Google Patents

Description

  The present invention relates to an automotive differential apparatus.

  The differential device is located in the vehicle's power train so that the outer wheels rotate faster than the inner wheels while turning, while maintaining a torque distribution equally divided between the left and right wheels, ensuring smooth turning. It is intended to be obtained.

  A typical differential device has a pair of side gears each composed of a bevel gear, and a pair of differential pinions. A pair of side gears arranged so as to face each other are splined to axles that transmit rotation to the left and right wheels, respectively.

  A pair of differential pinions are also arranged to face each other and mesh with both side gears. The differential pinion is fixed to a ring gear (mainly an external gear for FF vehicles and a bevel gear for FR vehicles), and the output of the transmission is transmitted to the ring gear. The differential pinion is arranged so that it can revolve together with the ring gear and can also rotate.

  A thrust washer is interposed between the side gear and the differential case to receive an axial thrust force. One surface of the thrust washer slides with the side gear, and the other surface slides with the inner surface of the differential case.

  This thrust washer is generally not fixed to either the differential case or the side gear and is merely interposed between the two, so that judder may occur depending on the degree of sliding.

To prevent this judder, the thrust washer is fixed to the differential case by providing a pair of protrusions on the outer peripheral surface of the thrust washer and fitting these protrusions into grooves formed on the inner surface of the differential case. Such a differential apparatus has been proposed in Japanese Patent Laid-Open No. 8-233068.
Japanese Unexamined Patent Publication No. 8-233068

  In the differential device described in Patent Document 1, since the thrust washer is fixed to the differential case, no sliding occurs between the thrust washer and the differential case.

  However, sliding occurred between the thrust washer and the side gear, and there was a risk of causing judder due to a change in sliding resistance on the surface of the thrust washer.

  The present invention has been made in view of the above points, and the object of the present invention is to perform processing on the surface of the thrust washer so that judder caused by sliding between the thrust washer, the side gear and the inner surface of the differential case can be obtained. Another object of the present invention is to provide a differential device that prevents generation and erroneous assembly of a mounting surface of a thrust washer.

According to the first aspect of the present invention, a differential case that rotatably supports a pair of axles, a pair of side gears that are spline-coupled to the axles and meshed with the differential pinion, respectively, and interposed between the side gears and the differential case. In the differential device having a pair of annular thrust washers, a surface of each annular thrust washer facing the side gear is coated, and at least three outer circumferential surfaces of each annular thrust washer are provided on the outer circumferential surface of each annular thrust washer. Protrusions are formed, and an inner surface of the differential case is formed with a plurality of recesses into which the respective protrusions are fitted, and at least three of the protrusions have different central angles sandwiched between adjacent protrusions. It is apart from arranged such that, two of said protrusions before It is formed at a point-symmetrical position with respect to the center of the thrust washer, a plurality of lubricating oil grooves are formed on the inner surface of the differential case, and the two convex portions formed at the point-symmetrical position The recessed portion into which the lubricating oil groove is partly used is combined, and the recessed portion into which the remaining one protruding portion is fitted is symmetric with the pointed inner surface of the differential case to which the annular thrust washer is attached. Two convex portions formed at positions are provided to be reversed left and right so as to face the concave portion where the convex portion is fitted, and the annular thrust washer is fitted to the concave portion, and the side gear and the differential case A differential device is provided which is interposed between the first and second terminals.

  According to the second aspect of the present invention, there is provided a differential apparatus in which the coating is formed from a resin coating.

  According to the first aspect of the present invention, the coating is applied only to the surface facing the side gear of the thrust washer, and at least three convex portions formed on the outer peripheral surface of the thrust washer have central angles sandwiched by the adjacent convex portions. By disposing them at different angles, it is possible to prevent erroneous attachment in which the coating surface of the thrust washer faces the inner surface of the differential case.

  Further, since the surface of the thrust washer facing the side gear is coated, the sliding resistance between the thrust washer and the side gear can be reduced, and the occurrence of judder can be suppressed.

  Furthermore, by applying the coating only to one side of the thrust washer, the dimensional variation in the thickness direction that occurs in the coating process can be reduced compared to the double-sided coating, and the meshing accuracy of the differential device can be reduced. Both securing and prevention of stick-slip are possible.

  According to the second aspect of the present invention, since the coating is a resin coating, the friction coefficient can be stably kept low even in a state where there is little lubrication at the initial stage of the start, so that the occurrence of stick slip can be suppressed.

  Furthermore, the resin coating on the outer peripheral surface of the thrust washer is eliminated, and the contact portion between the convex portion and the differential case is made a metal contact, so that the problem of the resin coating peeling can be avoided.

  With reference to FIG. 1, the structure of the differential apparatus 2 of embodiment of this invention is demonstrated in detail. In the description of the present embodiment, an example in which the present invention is applied to the front differential device 2 will be described.

  In FIG. 1, only a part of the transmission case 4 is shown. The differential device 2 includes a differential case 10 that is rotatably supported by a transmission case 4 via a pair of ball bearings 6 and 8.

  A final driven gear 12 is fixed to the differential case 10 by a plurality of bolts 14 (only one is shown). The differential case 12 has inboard portions (boss portions) 16 and 18 extending in the left-right direction of the vehicle body.

  A shaft end portion of the left axle 20 is rotatably supported on the inner periphery of the left inboard portion 16, and a shaft end portion of the right axle 22 is rotatably supported on the inner periphery of the right inboard portion 18. The pinion shaft 28 is supported in a pair of pinion shaft support holes 24, 26 formed in the differential case 10 so as to be positioned between opposed ends of the two axles 20, 22 and to be orthogonal to the axis of the two axles 20, 22. Has been.

  The pinion shaft 28 is fixed to the differential case 10 so that it cannot rotate and cannot be inserted and removed by inserting a pin 34 through a pin hole 30 formed at one end thereof and a pin hole 32 formed in the differential case 10.

  A pair of differential pinions 36, 38 are rotatably supported on the pinion shaft 28, and a pair of side gears (drive pinions) 40, 42 that mesh with the pair of differential pinions 36, 38 are a left axle 20 and a right axle 22. Are splined together.

  Curved thrust washers 44 and 46 are interposed between the back surfaces of the differential pinions 36 and 38 and the differential case 10, and a planar annular thrust washer is interposed between the side gears 40 and 42 and the differential case 10. 48 and 50 are interposed.

  The curved thrust washers 44 and 46 have a function of receiving a thrust force in the axial direction of the pinion shaft 28, and the thrust washers 48 and 50 have a function of receiving a thrust force in the axial direction of the axles 20 and 22.

  Between the oil seal 52 provided between the left axle 20 and the transmission case 4 and the left ball bearing 6, the final driven gear 12 rakes up and scatters, and is collected through a lubricating oil guide groove provided in the transmission case 4. An annular groove (annular space) 54 to which lubricating oil is supplied is formed.

  Similarly, a lubricating oil guide groove provided in the transmission case 4 is swept up and scattered by the final driven gear 12 between the oil seal 56 provided between the right axle 22 and the transmission case 4 and the right ball bearing 8. An annular groove (annular space) 58 is formed to which the lubricating oil collected along the path is supplied.

  Next, with reference to FIG. 2 thru | or FIG. 4, the detailed structure of the cyclic | annular thrust washers 48 and 50 which are the characteristics of this invention is demonstrated. Since the structure of the thrust washer 50 is the same as that of the thrust washer 48, the thrust washer 48 will be mainly described in the following description.

  The annular thrust washer 48 has three detent tabs (projections) 60, 62, 64 on its outer peripheral surface. The detent tab 62 is formed in a point-symmetrical position with the detent tab 60 with respect to the center of the annular thrust washer 48.

  In other words, the detent tab 62 is formed 180 degrees away from the detent tab 60 in the circumferential direction. The detent tab 64 is formed at a position where the central angle between the two detent tabs 60 and 64 is different from the central angle between the two detent tabs 62 and 64.

  A coating is applied to one side of the thrust washer 48, that is, the side facing the side gear 40. This coating is composed of a resin layer such as tetrafluoroethylene resin containing a filler (solid lubricant), for example.

  FIG. 3 is a view of the differential case 10 as viewed from the inner surface side. Two lubricating oil grooves 66 and 68 are formed on the inner surface of the differential case 10. Further, when the thrust washer 48 is interposed between the differential case 10 and the side gear 40 so that the resin coating 72 formed on one side of the thrust washer 48 faces the side gear 40 on the inner surface of the differential case 10, A recess 70 into which the stop tab 64 is fitted is formed.

  The anti-rotation tabs 60 and 62 are fitted to the end portions 66a and 68a of the oil supply grooves 66 and 68, respectively. As described above, since the three anti-rotation tabs 60, 62, 64 are fitted into the end portions 66 a, 68 a of the oil supply grooves 66, 68 and the recess 70, the thrust washer 48 is fixed to the differential case 10.

  Therefore, the thrust washer 48 does not slide with respect to the differential case 10, and sliding occurs only between the surface on which the resin coating layer 72 is applied and the side gear 40.

  However, since the resin coating layer 72 is blended with a solid lubricant, the friction coefficient can be stably kept low even in a state where the lubrication at the initial stage of the start is small, so that the friction between the side gear 40 and the thrust washer 48 is reduced. Generation | occurrence | production of the stick slip which generate | occur | produces can be suppressed. As a result, the occurrence of judder due to stick-slip can be prevented.

  A recess is formed on the inner surface of the right side of the differential case 10 to which the thrust washer 50 is attached, at a position where the left and right sides of the recess 70 shown in FIG. 3 are reversed, and the rotation of the thrust washer 50 is stopped in this recess. The tab 64 is designed to fit. Of course, the anti-rotation tabs 60 and 62 of the thrust washer 50 are fitted into the end portions 66a and 68a of the oil supply grooves 66 and 68, respectively.

  Since the positions of the recesses into which the anti-rotation tabs 64 are fitted are formed in opposite directions on the left and right inner surfaces of the differential case 10, the thrust washer 48 shown in FIG. 2 having the resin coating layer 72 only on one side is thrust. It can also be used as the washer 50.

  According to the present embodiment, by applying the resin coating layer for reducing the friction coefficient only to the surface facing the side gear of the thrust washer, when the differential device rotates due to turning and rough terrain, the side gear and Stick-slip generated on the sliding surface with the thrust washer can be suppressed, and noise and vibration caused by stick-slip can be reduced.

  In addition, by coating only one side of the thrust washer, it is possible to reduce the dimensional variation in the thickness direction that occurs during the coating process compared to double-sided coating, ensuring differential gear meshing accuracy and It is possible to achieve both stick-slip prevention and reduce coating process cost, process time and material cost.

  Furthermore, since the resin coating on the outer surface of the thrust washer has been eliminated, the contact portion between the detent tab and the differential case can be made into a metal contact, making it possible to both prevent the resin coating from peeling and stick slip. .

  In addition, in an embodiment where a part of the oil supply groove can also be used as a recess for fitting a non-rotating tab, in the case of a car model that does not require countermeasures against abnormal noise and vibration, there is no resin coating without changing the differential case It is possible to use a thrust washer. As a result, it is possible to selectively use the thrust washer with or without a coating depending on the vehicle type, and it is possible to reduce costs and man-hours.

  In the embodiment described above, the anti-rotation tabs 60 and 62 are arranged 180 degrees apart in the circumferential direction, but the present invention is not limited to this, and two adjacent anti-rotation tabs are sandwiched. What is necessary is just to arrange | position at least 3 detent | locking tabs so that a center angle may differ, respectively.

  By disposing the rotation stop tab in this manner, it is possible to prevent erroneous assembly that attaches the coated surface of the thrust washer toward the differential case 10 side.

  The coating is not limited to resin coating, and carbon film coating or metal plating may be applied only to one side of the thrust washers 48, 50.

  In the above-described embodiment, an example in which the present invention is applied to a front differential device has been described. However, the present invention is also applicable to a rear differential device for a four-wheel drive vehicle as described in Japanese Patent Application Laid-Open No. 2003-146099. It is.

  FIG. 4 shows a sectional view of the rear differential device 3 of the four-wheel drive vehicle. The rear differential device 3 is accommodated in a housing 5 shown only partially. The rear differential device 3 includes a differential case 11 that is rotatably supported by a housing 5 via a pair of ball bearings 7 and 9.

  A final driven gear 13 is fixed to the differential case 11 by a plurality of bolts 15 (only one is shown). The differential case 13 has inboard portions (boss portions) 17 and 19 extending in the left-right direction of the vehicle body.

  The shaft end portion of the left axle 21 is rotatably supported on the inner periphery of the left inboard portion 17, and the shaft end portion of the right axle 23 is rotatably supported on the inner periphery of the right inboard portion 19. The pinion shaft 29 is supported in a pair of pinion shaft support holes 25 and 27 formed in the differential case 11 so as to be positioned between the opposed ends of the two axles 21 and 23 and to be orthogonal to the axes of the two axles 21 and 23. Has been.

  The pinion shaft 29 is fixed to the differential case 11 so that it cannot rotate and cannot be inserted and removed by inserting a pin 35 through a pin hole 31 formed at one end of the pinion shaft 29 and a pin hole 33 formed in the differential case 11.

  A pair of differential pinions 37, 39 are rotatably supported on the pinion shaft 29, and a pair of side gears (drive pinions) 41, 43 that mesh with the pair of differential pinions 37, 39 are the left axle 21 and the right axle 23. Are splined together.

  Curved thrust washers 45 and 47 are interposed between the back surfaces of the differential pinions 37 and 39 and the differential case 11, and a planar annular thrust washer is interposed between the side gears 41 and 43 and the differential case 11. 49 and 51 are interposed.

  The curved thrust washers 45 and 47 have a function of receiving a thrust force in the axial direction of the pinion shaft 29, and the thrust washers 49 and 51 have a function of receiving a thrust force in the axial directions of the axles 21 and 23.

  An annular thrust washer 48 having a resin coating 72 on one side as shown in FIG. 2 can be adopted for the annular thrust washers 49 and 51 described above. Thus, the annular thrust washers 49 and 51 having the resin coating only on the surfaces facing the side gears 41 and 43 are used, and these thrust washers are fixed to the differential case 11 with the same structure as shown in FIG. As a result, the same effects as those of the front differential device 2 described with reference to FIG. 1 can be obtained.

It is a longitudinal cross-sectional view of the differential apparatus of this invention embodiment. It is a top view of a thrust washer. It is the figure which looked at the differential case from the inside. It is a longitudinal cross-sectional view of the rear differential apparatus which concerns on other embodiment.

Explanation of symbols

2 Differential device 10 Differential case 20, 22 Axle 28 Pinion shaft 36, 38 Differential pinion 40, 42 Side gear (drive pinion)
48, 50 Annular thrust washer 60, 62, 64 Anti-rotation tab 66, 68 Oil supply groove 70 Recess

Claims (2)

A differential case for rotatably supporting a pair of axles, a pair of side gears splined to each axle and meshing with each differential pinion, and a pair of annular thrust washers interposed between each side gear and the differential case Having a differential device,
The surface facing each side gear of each annular thrust washer is coated,
At least three convex portions are formed on the outer peripheral surface of each annular thrust washer,
The inner surface of the differential case is formed with a plurality of recesses into which the projections are fitted,
At least three of the convex portions are spaced apart so that the central angles between adjacent convex portions are different from each other,
Two of the convex portions are formed at positions symmetrical with respect to the center of the thrust washer,
A plurality of lubricating oil grooves are formed on the inner surface of the differential case, and a concave portion into which the two convex portions formed at the point-symmetrical positions are fitted is a part of the lubricating oil groove. ,
The concave portion into which the remaining one convex portion is fitted is opposed to the concave portion into which the two convex portions formed at the point-symmetric positions are fitted on the opposing inner surface of the differential case to which the annular thrust washer is attached. Is provided in the left-right reversal,
The differential apparatus, wherein the annular thrust washer is interposed between the side gear and the differential case with the convex portions fitted into the concave portions. The differential apparatus according to claim 1, wherein the coating is a resin coating.

Images