JPS6338586B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates primarily to a differential device for automobiles, and particularly to a structure for increasing lubrication within a differential case.

When the lubricating oil of the differential device rotates as the differential case rotates, it sticks to the outer circumferential surface of the case and rotates with it, causing a phenomenon such as cracking. For this reason, it is difficult for lubricating oil to flow into the differential case, and in particular, in a four-pinion type differential device in which the pinion shaft is supported at four points relative to the case, a large window must be opened in the peripheral wall of the case. Since this is not possible due to space constraints, insufficient lubrication within the case is likely to occur. Insufficient lubrication in the differential case can cause abnormal wear on the differential gears (side gears and pinions) and other friction parts, and the resulting noise. In the case of a differential device, this also causes wear on the friction plates that make up the multi-plate clutch.

Wear of each friction plate that makes up a multi-disc clutch not only reduces its durability, but also causes a decline in the differential limiting function due to changes in the friction characteristics of the multi-disc clutch, or abnormalities due to stick slip between the friction plates. This may cause inconveniences such as noise generation.

In view of such conventional circumstances, the present invention provides an opening formed in the peripheral wall of the differential case within the range that the space allows.
The object of the present invention is to provide a lubrication structure that can forcibly introduce lubricating oil into the case, thereby improving the lubricity of each member incorporated within the case.

In order to achieve the above object, the present invention forms an opening for lubricating oil in the peripheral wall of a differential case, and uses the edge of this opening to actively distribute lubricating oil through rotation of the case. The device is characterized by forming a guide surface and a deflector that allow the material to be introduced into the case.

Next, the configuration of the present invention described above will be explained in detail according to embodiments shown in the drawings.

In FIG. 1, which is a cross-sectional view of the main parts of an automobile differential device equipped with a preload type differential limiting device, and in FIG. 2, which is a partially enlarged view of FIG. 1 is rotatably supported by side bearings (tapered roller bearings) on differential carriers (not shown). Further, a ring gear (not shown) is fixed to a flange portion 3 integrally formed on the outer periphery of the differential case 1, and the case 1 transmits torque from a drive pinion (not shown) through this ring gear. is configured to receive. A pair of side gears 6 and four pinions 8 are installed inside the differential case 1 in a mutually engaged state. Note that left and right axle shafts (not shown) are respectively inserted into the case 1 through the inner holes of the left and right cylindrical parts 2 mentioned above, and the inner ends of these shafts are formed on the inner periphery of the sleeve part 7 of both side gears 6. It is integrally centered and fitted to the inner spline 7b. Also,
Each of the pinions 8 described above is rotatably supported by a pinion shaft 9 which is formed in a cross shape and whose ends are supported by the case 1 .

A ring-shaped holding portion 9a is integrally formed in the center of the pinion shaft 9, and both side surfaces of this holding portion 9a and inner end surfaces 6a of both side gears 6
A disk-shaped retainer 10 is interposed between the two. Both of these retainers 10 are capable of relative displacement (mutual movement away from and approaching each other) in the left-right direction in FIG. The retainer (located on the left side in FIG. 1) is prevented from rotating with respect to the holding portion 9a. A preload spring 11 made of a combination of large-diameter and small-diameter coil springs is incorporated into the holding portion 9a.
is connected to both side gears 6 via both retainers 10 mentioned above.
It acts to press the left and right direction.

A multi-plate clutch 5 for limiting differential movement is provided between the rear surface 6b of the above-mentioned both side gears 6 and the inner surface 20 of both side walls of the differential case 1 facing thereto.
0 is arranged respectively. These multi-plate clutches 50 alternately arrange a plurality of friction plates 51 which are prevented from rotating by the sleeve portion 7 of the side gear 5 and a plurality of friction plates 52 which are prevented from rotating by the differential case 1. It is composed of: That is, as is clear from FIG. 3, which shows a cross section viewed from the - arrow direction in FIG.
is an inner spline 51a on the inner periphery of the center hole.
is assembled by being fitted into an outer spline 7a formed on the outer periphery of the sleeve portion 7 of the side gear 6. Further, the friction plate 52 that is prevented from rotating by the case 1 has a plurality of protrusions 52a formed on its outer periphery.
is assembled by being engaged with a locking groove 4 formed on the inner periphery of the case 1 (see FIG. 3). Due to this anti-rotation structure, each friction plate 51, 52 can slide freely in the axial direction (left and right direction in FIG. 1), and can rotate integrally with both side gears 6 or the case 1 in the rotation direction. becomes. The friction plates 51 and 52 of the multi-plate clutch 50 are brought into pressure contact with each other by the elasticity of the preload spring 11 acting on both side gears 6 and the reaction force of the engagement between the pinion 8 and the side gear 6. Retained. As a result, both side gears 6
is subjected to a differential limiting action due to the frictional resistance of the multi-plate clutch 50.

In addition, the above differential case 1 is
As is clear from FIG. 4, in which all internal components are omitted, the structure is divided into left and right halves from approximately the center, and in each divided state, the aforementioned side gear 6 , pinion 8, preload spring 11, multi-plate clutch 50, and other related components, and then the left and right divided cases 1A, 1B are integrally connected with bolts 5.

Lubricating oil in a differential carrier (not shown) is applied to the peripheral wall 12 of the differential case 1 constructed as described above.
A plurality of openings 13 are formed for guiding the inside. That is, four openings 13 are formed at regular intervals in the circumferential direction in each of the left and right divided cases 1A and 1B (Fig. 3,
(See Figure 4). The opening 13 of the left divided case 1A is clearly shown in FIG. 5, which shows a cross section viewed from the direction of the - arrow in FIG. 4. These openings 13 are aligned in the rotational direction P of the differential case 1 shown in FIGS. 3, 4, and 5.
Regarding case 1 on the side preceding the opening 13
The outer circumferential surface forms a guide surface 14 that is inclined to become gradually lower toward the opening 13. The edge of the opening 13 on the side facing the guide surface 14 forms a deflector 15 that forms a slightly acute angle with respect to the guide surface 14 . Furthermore, as is clear from FIG. 6, which is a perspective view of the area where each opening 13 is formed, the inner surface of the peripheral wall 12 is partially recessed. An oil reservoir 17 is formed. Further, a stopper surface 16 is formed between these oil reservoirs 17 and the openings 13 to receive lubricating oil flowing from the openings 13 and properly guide it to the oil reservoirs 17.

Next, the lubricating action within the differential case 1 will be explained. First, in a stationary state where no rotation is transmitted to the differential case 1, the lubricating oil level L in the differential carrier (not shown) is at the position shown in FIG. Therefore, when the rotation is transmitted to the differential case 1 and it begins to rotate in the direction of the arrow P mentioned above, the lubricating oil is stirred by the case 1 and the ring gear (not shown) rotating together with the lubricating oil. If a part of the case 1 is attached to the outer circumferential surface of the case 1 and moved around, a phenomenon such as irritation occurs. As the case 1 rotates, this oil flows along the guide surface 14 of each opening 13 described above, and flows through the deflector 1.
5 into the case 1 (see dotted arrows in FIGS. 3 and 5). The oil that has flowed into the case 1 in this way is absorbed by the stopper surface 16.
The oil is received by the case 1, and each oil reservoir 1 is
7 (see especially the dotted line arrow in FIG. 6), and is temporarily stored in this oil reservoir 17. The oil stored in this oil reservoir 17 is transferred to each friction plate 51, 5 of the multi-plate clutch 50.
It is supplied between the two and lubricates their friction surfaces. Further, each of the oil reservoirs 17 causes turbulence in the oil flow within the case 1, and each friction plate 51, 5
The lubricating effect of No. 2 is further enhanced. In this way, the oil flowing along the outer periphery of the case 1 can be controlled by the guide surface 14 of the opening 13 and the deflector 15 without forming any projections or fins on the outer periphery of the case 1 to introduce the oil. It is properly introduced into the case.

Note that the above-mentioned lubrication effect not only improves the lubricity of the friction plates 51 and 52 of the multi-plate clutch 50, but also improves the lubricity between the side gear 6 and pinion 8 and other friction parts in the case 1. Naturally, lubricity can also be improved. Therefore, the lubrication structure of this embodiment can also be applied to a normal differential device that is not equipped with the multi-plate clutch 50 for limiting differential movement. Moreover, although the above-mentioned opening 13 is formed in each of the divided cases 1A and 1B, a sufficient lubrication effect can be obtained even if it is formed in only one of the divided cases. However, in this case, the opening 13 is larger in the left divided case 1B than in the left divided case 1A to which the ring gear is fixed.
This is advantageous in obtaining the opening space.

As described above, the present invention makes it possible to actively introduce lubricating oil into the case by utilizing the rotation of the differential case through the opening formed in the peripheral wall of the differential case. The lubrication effect inside the case can be sufficiently enhanced even if the opening is formed with Inconveniences such as deterioration of the differential limiting function and generation of abnormal noise due to this can be avoided. Moreover, in the case of this invention, the guide surface and the deflector, which are located on the outer periphery of the differential case and are used to actively introduce lubricating oil into the interior through the openings, do not have a shape that protrudes from the outer periphery of the case. Therefore, it is possible to avoid increasing the size of the differential carrier in which the differential case is accommodated. Note that if the deflector is set at a slightly acute angle with respect to the guide surface, oil flowing along the guide surface can be effectively introduced into the case.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a partially cutaway plan view of an automobile differential device equipped with a differential limiting device, and FIG.
A cross-sectional view showing a part of the figure enlarged, Figure 3 is the 1st
Fig. 4 is a partially cutaway plan view of only the differential case at a different position from Fig. 1; Fig. 4 is a sectional view taken from the arrow - in a state where Fig. 4 is regarded as a complete view, and Fig. 6 is a perspective view showing the structure inside the case near the opening. 1...Differential case, 6...Side gear, 8...Pinion, 12...Peripheral wall, 13...Opening, 1
4...Guide surface, 15...Deflector, 17...Oil sump,
50...Multi-plate clutch.

Claims (1)

[Scope of Claims] 1. A differential device comprising a pair of side gears and a pinion that meshes with these gears incorporated inside a differential case, wherein a peripheral wall of the differential case includes: An opening for lubricating oil that communicates with the inside and outside of the case is formed, and the opening is inclined downwardly toward the opening from the outer peripheral surface of the case on the side that precedes the opening in the direction in which the differential case rotates. A lubrication structure characterized in that a guide surface is formed, and an edge of an opening facing the guide surface is a deflector capable of receiving lubricating oil flowing along the guide surface. 2. The lubrication structure according to claim 1, wherein the deflector is set at a surface forming a slightly acute angle with respect to the guide surface. 3. The lubrication structure according to claim 1 or 2, wherein a part of the lubricant flow path leading from the opening into the differential case is an oil reservoir.