JPH0854052A - Lubricating structure of differential mechanism - Google Patents

Abstract

PURPOSE:To reduce an agitation loss through reduction of a total amount of lubrication oil by reliably guiding lubricating oil to each part of a differential mechanism. CONSTITUTION:A protrusion part 12 with which lubricating oil flied by a ring gear 7 is brought into contact is formed in a position above the ring gear 7 integrally with a housing 4. An oil reservoir 15 in which the lubricating oil flying resultant from contact with the protrusion part 12 is guided is formed in a position deviated in an axial direction from the ring gear 7 and above a differential gear case 5. An opening part 16 through which lubricating oil from the oil reservoir part 15 is dripped is formed in the part, corresponding to a position above a window hole 11, of the oil reservoir part 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubrication structure in a differential mechanism for performing differential between left and right wheels of a vehicle and front and rear wheels.

[0002]

2. Description of the Related Art For a final reduction gear of a vehicle and a center differential gear that distributes driving force to front and rear wheels, a pinion gear is held by a pinion pin in a differential gear case integrated with a ring gear so as to rotate freely.
Further, a differential mechanism is used in which a pair of side gears meshing with the pinion gear are rotatably held inside a differential gear case. As a lubrication method of this type of differential mechanism, so-called splash lubrication is adopted, and the lubricating oil accumulated at the bottom of the housing is splashed by a ring gear and supplied to tooth surfaces, bearings and the like. With such splash lubrication, when the amount of lubricating oil is small, or when the ring gear is rotating at high speed, the amount of lubricating oil accumulated at the bottom of the housing may be insufficient and sufficient lubrication may not be achieved. In some cases, the supply of lubricating oil to the pinion gears and bearings provided inside the differential mechanism may become insufficient.

In order to eliminate such inconvenience, in the invention disclosed in Japanese Patent Laid-Open No. 59-69568, an oil sump is provided above the housing, and an oil passage communicating with this oil sump is provided in a case or a rotating shaft. The lubricating oil that is formed inside and is splashed up by the ring gear is supplied from the oil reservoir to the central portion such as the bearing through the oil passage.

[0004]

In the splash lubrication, it is not necessary to provide a special lubrication mechanism, but the lubricating oil is agitated, which causes disadvantages such as loss of power and increase of oil temperature. Such inconvenience occurs when the rotating member such as the ring gear is in contact with the lubricating oil accumulated in the oil sump, and even in the invention described in the above publication, the oil that collects the lubricating oil splashed by the ring gear is stored. A puddle
Since the ring gear is installed above the ring gear and close to the ring gear, the ring gear agitates the lubricating oil in the oil sump, resulting in power loss and increase in oil temperature. is there.

The present invention has been made in view of the above circumstances, and provides a lubrication structure for a differential mechanism capable of reducing agitation loss and sufficiently supplying lubricating oil to the central portion of a pinion gear or the like. The purpose is to do.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention receives a lubricating oil splashed by a ring gear at a protrusion provided on the outer peripheral side thereof and places the lubricating oil away from the ring gear. It is configured such that it is guided to the oil sump portion and further supplied from there to the inside of the differential mechanism through the window hole of the differential gear case.
That is, according to the present invention, a differential gear case, which is integrated with a ring gear and has a window hole formed therein, is rotatably held inside a housing, and the pinion gear is attached inside the differential gear case by a pinion pin attached to the differential gear case. In a lubrication structure of a differential mechanism in which a pair of side gears that are rotatably supported and meshed with the pinion gears are rotatably held inside the differential gear case, the lubricating oil scattered above the ring gear by the ring gear And a position above the differential gear case in which the oil sump that abuts the projection and guides the scattered lubricating oil is axially displaced from the ring gear. It is formed, in which further a portion corresponding to a position above the window opening of the oil reservoir, wherein the opening for dropping the lubricating oil from the oil reservoir is formed.

[0007]

In the lubricating structure of the present invention, when the ring gear integrated with the differential gear case rotates,
Lubricating oil is splashed up by the ring gear, and a part of the lubricating oil is scattered in the close engagement direction of the ring gear. A part of the lubricating oil scattered from the tangential direction of the ring gear comes into contact with a protrusion located above the ring gear and is scattered in multiple directions. A part of the lubricating oil thus scattered by the protrusions is introduced into the oil sump and is gradually accumulated there. Since the oil sump portion is provided at a position deviated from the ring gear in the axial direction, the lubricating oil therein is not agitated by the ring gear.

Since the ring gear is rotating, the lubricating oil is continuously introduced into the oil sump, while the lubricating oil is dripped from the opening formed in the oil sump. Since this opening is provided in a portion corresponding to the upper position of the window hole formed in the differential gear case, the lubricating oil dripping from the opening can be absorbed by the window because the differential gear case is rotating together with the ring gear. It goes into the inside through the hole. As a result, the lubricating oil is sufficiently supplied to the pinion pin, the pinion gear, the side gear, etc. provided inside the differential gear case.

[0009]

The present invention will now be described in detail with reference to the embodiments shown in the drawings. The embodiment shown in FIG. 1 to FIG.
An example in which the present invention is applied to a differential mechanism incorporated in a transaxle of a vehicle (front-mounted engine front-wheel drive vehicle),
The differential mechanism 1 shown here is housed inside a housing 4 composed of a clutch case 2 and a transmission case 3. That is, the differential gear case 5 is rotatably held inside the housing 4 via bearings 6 fitted to both ends thereof, and the ring gear 7 is integrally attached to the differential gear case 5. In addition, inside the differential gear case 5,
A pair of left and right side gears 8 are rotatably housed in a state in which the central axis is aligned with the central axis of the differential gear case 5, and a pinion gear 9 meshing with these side gears 8 is rotatably attached to a pinion pin 10. There is. The pinion pin 10 is attached to the differential gear case 5 by penetrating the differential gear case 5 in the direction orthogonal to the rotation center axis thereof. In addition, the differential gear case 5
Has window holes 11 formed at two locations that face each other in the radial direction.

The vertical direction in FIGS. 1 and 3 is the vertical direction when the vehicle is mounted, and the projection 12 is provided above the ring gear 7 in this state. The projection 12 is formed by projecting a part of a rib 13 formed on the inner wall surface of the housing 4, more specifically, the inner wall surface of the clutch case 2, above the ring gear 7. In the example shown in the drawing, the shape of the protrusion 12 is a rectangular plate shape, and extends from the side portion of the ring gear 7 and projects to a position where it overlaps a part of the outer peripheral side thereof.

The rib 13 integral with the protrusion 12 is located on the upper side of the differential gear case 5, and another rib 14 is formed in parallel with the rib 13. That is, an oil sump 15 is formed by these ribs 13 and 14. Therefore, the oil sump 15 is disengaged from the outer peripheral side of the ring gear 5 and is separated from the differential gear case 5.
Is provided on the outer peripheral side, that is, above the differential gear case 5. And the ribs 13 and 14
The lower end portion between the two is cut out for a predetermined length to form an opening 16, and the opening 16 is located above the window hole 11 formed in the differential gear case 5.

Lubricating oil is contained in the housing 4 so that the lower end of the ring gear 7 is immersed therein.
When the ring gear 7 rotates in the direction shown by the arrow in FIGS. 3 and 4, the lubricating oil is splashed up by the ring gear 7. A part of the lubricating oil attached to the ring gear 7 scatters in the tangential direction by the centrifugal force, and a part of the lubricating oil abuts on the protrusion 12.
The kinetic energy of the lubricating oil abutted on the projections 12 and scattered causes the lubricating oil to enter the oil sump 15 as shown by the arrows in FIGS. 3 and 4, and gradually accumulate there.

Lubricating oil inside the oil sump 15 gradually drips from the opening 16 due to gravity, but since the opening 16 is located above the window hole 11 formed in the differential gear case 5, the opening is not opened. The lubricating oil dropped from 16 enters the inside of the differential gear case 5 through the window hole 11. The lubricating oil thus supplied to the inside of the differential gear case 5 is the pinion pin 1
0, the pinion gear 9 or the side gear 8 is supplied to bearing portions or tooth surfaces and used for lubrication of these portions. The lubricating oil thus sent to the lubrication point flows down along the inner wall surface of the housing 4, or is shaken off by the differential gear case 5 and flows down to the bottom of the housing 4. Then, from here, it is rebounded by the ring gear 7 and sent to the place to be lubricated.

Therefore, in the above-mentioned lubrication structure,
Oil sump 15 that stores the lubricating oil splashed by the ring gear 7.
However, since the ring gear 7 is provided at a position deviated from the ring gear 7 in the axial direction thereof, the lubricating oil splashed by the ring gear 7 is not further stirred by the ring gear 7, and thus the stirring loss can be reduced. The lubricating oil once stored in the oil sump 15 is dripped from the opening 16 toward the window hole 11 of the differential gear case 5,
The inside of the differential mechanism 1 can be lubricated in a necessary and sufficient manner. Lubricating oil can be sufficiently and surely supplied to necessary parts including the internal mechanism such as the pinion gear 9 and the side gear 8, so that the amount of lubricating oil can be suppressed to a necessary minimum. In other words, the total amount of the lubricating oil in the housing 4 can be reduced as compared with the conventional one, so that the power loss due to stirring the lubricating oil can be suppressed also in this respect.

In the above-mentioned embodiment, the shape of the protrusion is a rectangular plate, but the shape of the protrusion in the present invention can be any shape as required, and the area thereof is The amount can be appropriately set in consideration of the amount of lubricating oil to be introduced into the oil sump and the amount of lubricating oil to be splash-lubricated to other places. Further, the present invention is not limited to the final reduction gear built in the front axle shown in the above-mentioned embodiment, but can be applied to lubrication of other differential mechanisms.

[0016]

As described above, according to the lubricating structure of the present invention, the lubricating oil scattered from the ring gear is captured by the protrusion and introduced into the oil sump, and the oil sump is passed from the ring gear to its axis. Since it is formed at a position deviated in the direction, and the lubricating oil is dropped from this into the window hole of the differential gear case, the degree of stirring of the lubricating oil by the ring gear decreases and the power generated by stirring the lubricating oil decreases. Loss can be suppressed, and moreover, lubricating oil can be reliably supplied to the inside of the differential gear case. As a result, a small amount of lubricating oil enables necessary and sufficient lubrication, thus reducing the total amount of lubricating oil. It can be reduced to further reduce the stirring loss.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view for explaining the structure of the differential mechanism.

FIG. 3 is a front view of a clutch case for explaining positions and shapes of a protrusion and an oil sump.

FIG. 4 is a schematic perspective view for explaining the shapes of a protrusion and an oil sump.

[Explanation of symbols]

 1 differential mechanism 4 housing 5 differential gear case 7 ring gear 8 side gear 9 pinion gear 11 window hole 12 protrusion 15 oil sump 16 opening

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Go Sakai 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd.

Claims (1)

[Claims] 1. A differential gear case, which is integrated with a ring gear and has a window hole formed therein, is rotatably held inside the housing, and a pinion gear is attached inside the differential gear case by a pinion pin attached to the differential gear case. In a lubrication structure of a differential mechanism in which a pair of side gears that are rotatably supported and meshed with the pinion gears thereof are rotatably held inside the differential gear case, the lubricating oil scattered above the ring gear by the ring gear And a position above the differential gear case in which the oil sump that abuts the projection and guides the scattered lubricating oil is axially displaced from the ring gear. Formed into It is further lubrication structure of the differential mechanism to a portion corresponding to a position above the window opening of the oil reservoir, wherein an opening for dropping the lubricating oil from the oil reservoir is formed.