JPH09250623A - Differential gearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production cost competitive differential gear device having a viscous coupling. SOLUTION: A differential gear case 1 in a differential gear device 100 has a bowl-like case body 2 and a flange-coupled cover body 3 to close the opening of the case body 2. A retainer 20 having an engaging support part 21 for relatively unturnably engaging with an outer plate 26, and a flange part 22 pinchingly fixed to the flange coupling part of the case body 2 and the cover body 3 engages in the rotation direction outer plate 26 with the differential gear case 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential gear device that absorbs a rotational speed difference between left and right drive shafts during turning of a vehicle, and more specifically limits a differential between the left and right drive shafts. The present invention relates to a differential gear device including a viscous coupling.

[0002]

2. Description of the Related Art Conventionally, a differential gear device is mounted between left and right drive shafts in order to absorb a difference between inner and outer wheels generated when a vehicle turns. However, in a normal differential gear device, when one of the left and right drive wheels starts idling due to falling into a muddy state or riding on ice or snow on the road surface, the drive force cannot be transmitted to the other drive wheel. Therefore, in recent years, viscous resistance generated between a large number of thin plates arranged in a highly viscous fluid such as silicon oil is used to generate a differential limiting torque in accordance with the rotational speed difference between the left and right drive shafts. Differential gears with viscous couplings are widely used.

An example of such a differential gear device with a viscous coupling will be described with reference to FIG. The differential gear device 200 shown in FIG. 5 has a bowl-shaped case body 32 and a lid 33 that closes the opening of the case body 32.
And a differential gear case 31 composed of Further, bearings (not shown) are fitted to the tubular portion 4 formed at the right end portion of the case main body 32 in the drawing and the tubular portion 5 formed at the left end portion of the lid 33 in the drawing. Then, these bearings are supported by a differential carrier (not shown), and the differential gear case 31 is rotationally driven around the rotation axis C.

The case body 32 has the rotation axis C.
A pinion shaft 6 extending so as to be orthogonal to is fixed by a retaining pin 7. A pinion gear 8 is rotatably fitted to the pinion shaft 6, and is fitted to the case main body 32 and the lid 33 so as to be rotatably supported coaxially with the rotation axis C. 9 and 10 mesh with the pinion gear 8. As a result, when the differential gear case 31 is integrally driven to rotate about the rotation axis C, the rotational driving force is distributed to the pair of left and right side gears 9 and 10 via the pinion shaft 6 and the pinion gear 8. , 10 respectively, a pair of left and right drive shafts (not shown) that are first and second output shafts that are spline-engaged with spline portions 11 and 12 respectively, are rotationally driven.

Further, the case main body 32 and the lid 33 and the side gear 10 on the left side in the drawing form an annular working chamber 13 coaxial with the rotation axis C. The working chamber 13 is filled with silicone oil as a highly viscous fluid. Further, spline teeth 14 are engraved on the inner peripheral surface of the case body 32 facing the working chamber 13. The spline teeth 14 have the working chamber 1
Outer plate 1 of a plurality of annular thin plates arranged in 3
The outer peripheral edge portion of 5 is engaged in a non-rotatable manner. Similarly,
Spline teeth 16 are formed on the outer peripheral surface of the side gear 10 facing the working chamber 13. The outer plate 15 and the rotation axis C are attached to the spline teeth 16.
Inner peripheral edge portions of a plurality of annular thin inner plates 17 arranged in the working chamber 13 so as to be alternately arranged in the direction are relatively non-rotatably engaged.

Therefore, when either one of the left and right drive wheels falls into a muddy state and runs idle, a difference in rotational speed occurs between the left and right side gears 9 and 10. As a result, a rotational speed difference is generated between the differential gear case 31 and the left side gear 10 in the drawing, so that the outer plate 15 and the inner plate 17 relatively rotate around the rotation axis C.
Then, a differential limiting torque is generated between the plates 15 and 17 due to the shear resistance of the silicone oil sealed in the working chamber 13. Since this differential limiting torque acts between the differential gear case 31 and the side gear 10, that is, between the left and right driving wheels, the differential limiting torque is equal to the driving wheel on the opposite side of the idling driving wheel. A large amount of rotational drive force is transmitted, and the vehicle can escape from the muddy area.

[0007]

By the way, as shown in FIG. 5, since the case main body 32 is formed in a bowl shape so as to integrally form the tubular portion 4 at the right end portion in the figure, the spline is formed. The teeth 14 cannot be formed by a processing method suitable for mass production such as broaching. Thereby, the spline teeth 14 are formed by cutting the inner peripheral surface of the case body 32 that has been conventionally cast by using a hobbing machine or the like. Therefore, in the conventional differential gear device 1, there is a problem that the tact time required for cutting the spline teeth 14 becomes long and the manufacturing cost required for machining the case body 32 increases.

Further, in order to secure the escape of the cutter of the hobbing machine forming the spline teeth 14, the spline teeth 14
It is necessary to previously form the concave groove 18 on the inner side adjacent to. Therefore, the outer plate 15 is provided in the groove 18.
It is necessary to fit the stopper ring 19 for preventing the falling of the parts, which causes a problem of increasing the cost of parts. Therefore, an object of the present invention is to solve the above problems, and to provide a differential gear device that includes a viscous coupling and is inexpensive to manufacture.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a differential gear case that is driven and rotated around the axes of a first output shaft and a second output shaft that are coaxial with each other, and the differential gear. A viscous fluid, and a differential gear unit that is rotatably housed in the case and that rotates integrally with the first and second output shafts and that has first and second transmission members that are differentially rotatable with respect to each other. A sealed working chamber, an outer plate set that engages with the differential gear case in the working direction in the working chamber, and an outer plate set and the second transmission member that are alternately arranged in the working chamber. A differential gear device, comprising: a differential limiting means having an inner plate set that engages in a rotational direction, wherein the differential gear case closes a bowl-shaped case body and an opening of the case body. With a lid that is flanged At the same time, a plate mounting member including an engagement support portion that engages with the outer plate set in a non-rotatable manner, and a flange portion that is sandwiched and fixed to a flange coupling portion of the case body and the lid body is the outer plate. This is achieved by a differential gearing characterized in that the set is rotationally engaged with the differential gear case.

Preferably, the flange portion of the plate mounting member is provided with an elastically deformable sealing portion projecting over the entire circumference of the flange so as to liquid-tightly seal the viscous fluid in the working chamber. That is, according to the differential gear device of the present invention, since the outer plate set engages with the differential gear case in the rotational direction via the plate mounting member, the outer plate set and the outer plate set are attached to the inner peripheral surface of the differential gear case. There is no need to machine spline teeth that engage in the rotational direction.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a differential gear device according to the present invention will be described in detail below with reference to FIGS. Here, FIG. 1 is a half cross-sectional view of a differential gear device according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of a main part of the differential gear device shown in FIG. 1, and FIG. 3 is shown in FIG. FIG. 4 is an exploded perspective view of a main part of the differential gear device, and FIG. 4 is a sectional view taken along the line AA shown in FIG. In the following description, the same parts as those of the conventional differential gear device are designated by the same reference numerals, and detailed description thereof will be omitted.

The differential gear device 100 of the present invention, like the conventional differential gear device 200 shown in FIG. 5, has a bowl-shaped case body 2 and a lid for closing the opening of the case body 2. A differential gear case 1 including a body 3 is provided. The differential gear case 1 is integrated by flange connection of the flange 2a of the case body 2 and the flange 3a of the lid 3 with a bolt (not shown).
Inside the case body 2, a pinion shaft 6 extending orthogonal to the rotation axis C of the differential gear case extends. A pinion gear 8 is rotatably fitted to the pinion shaft 6, fitted to the case main body 2 and the lid 3, rotatably supported coaxially with the rotation axis C, and differentially rotated with respect to each other. A pair of left and right side gears 9 and 10, which are possible first and second transmission members, mesh with the pinion gear 8.

An annular working chamber 13 coaxial with the rotation axis C is formed by the case body 2 and the lid body 3 and the side gear 10 which is the second transmission member on the left side in the drawing.
The working chamber 13 is filled with silicone oil as a highly viscous fluid. In the working chamber 13, a plurality of annular thin outer plates 26 are arranged as an outer plate set. Then, as will be described later, these outer plates 26 engage with the engagement support portions 21 of the retainer 20, which is a plate attachment member attached to the inner peripheral surface 2b of the case body 2, at the outer peripheral edge portions thereof, It rotates together with 2.

Further, in the working chamber 13, a plurality of annular thin inner plates 17 as an inner plate set are arranged so as to be alternately arranged with the outer plates 26. The inner peripheral edges of these inner plates 17 engage with the spline teeth 16 formed on the outer peripheral surface of the side gear 10, and rotate integrally with the side gear 10. Therefore, between the side gear 10 and the case body 2,
A viscous coupling is configured to generate a differential limiting torque according to the rotational speed difference between the left and right drive shafts.

As a result, when one of the left and right drive wheels spins and the outer plate 26 and the inner plate 17 rotate relative to each other around the rotation axis C, both plates 26, 1 are rotated.
During 7, the differential limiting torque is generated due to the shear resistance of the silicone oil sealed in the working chamber 13. Then, the differential limiting torque acts between the left and right driving wheels, and the rotational driving force having the same magnitude as the differential limiting torque is transmitted to the driving wheel on the opposite side of the idling driving wheel.

The retainer 20 is manufactured by pressing a metal plate as shown in FIG. 3, and has a cylindrical engagement support portion 21 which is fitted into the inner peripheral surface 2b of the case body 2. have. A flange portion 22 extending outward in the radial direction is provided upright over the entire circumference in the end portion of the engagement support portion 21 on the lid 3 side.

The flange portion 22 is provided with a plurality of bolt insertion holes 23 so that the centers thereof coincide with the plurality of bolt insertion holes penetrating the flange 2a of the case body 2 and the flange 3a of the lid 3, respectively. It is installed throughout. The flange portion 22 is clamped and fixed by the flange 2a and the flange 3a when the case body 2 and the lid body 3 are flange-joined by a bolt (not shown),
It is fixed integrally with the differential gear case 1.

Further, on the side surface of the flange portion 22 on the lid body 3 side, there is provided a sealing projection 24 which is an elastically deformable sealing portion for liquid-tightly sealing the silicone oil in the working chamber 13.
The flange is projected all over by embossing. As a result, when the case body 2 and the lid body 3 are flange-joined, the sealing projection 24 is compressed and deformed by the flange 2a of the case body 2 and the flange 3a of the lid body 3, and thus the case body. It comes into close contact with both 2 and the lid 3. Therefore, the silicone oil sealed in the working chamber 13 does not leak out through the gap between the flange 2a of the case body 2 and the flange 3a of the lid 3.

Further, as shown in FIG. 3, a plurality of engaging projections 25 having a corrugated cross section, which extend parallel to the rotation axis C, project from the inner peripheral surface of the cylindrical engaging support portion 21. Has been done. Further, a plurality of notches capable of engaging with the engaging projections 25 are formed on the outer peripheral edge portions of the plurality of outer plates 26 arranged inside the working chamber 13. This allows
As shown in FIG. 4, the outer plate 26 rotationally engages with a plurality of engaging protrusions 25 provided on the inner peripheral surface of the retainer 20, and is integrated with the retainer 20, that is, the differential gear case 1. It is configured to rotate.

Further, as shown in FIGS. 2 and 3, a taper portion 27 is coaxially connected to the engagement support portion 21 on the side opposite to the flange 22. As a result, the outer plate 26 comes into contact with the tapered portion 27, and its displacement in the rotation axis C direction is prevented. Therefore, unlike the conventional differential gear device 200 shown in FIG. 5, it is not necessary to mount the stopper ring 19 for preventing the displacement of the outer plate, and the cost of parts can be reduced.

Further, a cylindrical seal portion 28 is continuously provided at the tip of the taper portion 27. The X seal 29 attached to the outer peripheral surface of the side gear 10 is in contact with the inner peripheral surface of the seal portion 28. This retainer 2
Since 0 is a press-formed metal plate, a slight spring back cannot be avoided, and a force is applied to the seal portion 28 to displace it radially inward to reduce its diameter. At this time, since the X seal 29 is in contact with the inner peripheral surface of the seal portion 28, the X seal 29 and the seal portion 2
This is suitable for maintaining close contact with the silicone rubber 8 and preventing the silicone oil in the working chamber 13 from leaking to the outside.

That is, the differential gear device 10 of the present embodiment.
At 0, since the outer plate 26 is engaged with the case body 2 in the rotational direction via the retainer 20, the inner peripheral surface 2b of the case body 2 has spline teeth that engage with the outer plate 26 in the rotational direction. Since it is not necessary to form the case by machining, the manufacturing cost of the case body 2 can be significantly reduced. Further, the retainer 20 can be integrally formed by press working, is fitted to the inner peripheral surface 2b of the case body 2, and the flange portion 22 is sandwiched by the flange 2a of the case body 2 and the flange 3a of the lid body 3. It can be attached simply by fixing it and is easy to assemble.
Further, since the sealing projection 24 provided on the flange portion 22 of the retainer 20 is compressed and deformed and comes into close contact with the flange joint portion of the case body 2 and the lid body 3, a sealing for keeping the working chamber 13 liquid-tight. The part can also be integrally molded.

Therefore, although the differential gear device 100 is provided with the viscous coupling for generating the differential limited torque, the manufacturing cost of the differential gear device 100 can be significantly reduced as compared with the conventional differential gear device 200. You can It is needless to say that the differential gear device according to the present invention is not limited to the above-described embodiment and various modifications can be made.

[0024]

According to the differential gear device of the present invention as described above, the plate mounting member in which the outer plate set constituting the viscous coupling which is the differential limiting means is mounted on the inner peripheral surface of the differential gear case. Since it is configured to be engaged with the differential gear case in the rotational direction via, it is not necessary to directly machine the inner peripheral surface of the differential gear case with the spline teeth that engage with the outer peripheral edge portion of the outer plate set. Further, the plate mounting member is rotatably mounted integrally with the differential gear case by being clamped and fixed to the flange coupling portion of the case body and the lid body, so that the assembly is easy. Therefore, the manufacturing cost and time required for machining the differential gear case can be significantly reduced, and the manufacturing cost of the entire differential gear device can be reduced.

[Brief description of drawings]

FIG. 1 is a half cross-sectional view of a differential gear device according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of the differential gear device shown in FIG.

3 is an exploded perspective view of essential parts of the differential gear device shown in FIG.

4 is a cross-sectional view taken along the line AA shown in FIG.

FIG. 5 is a half sectional view of a conventional differential gear device.

6 is a cross-sectional view taken along the line BB shown in FIG.

[Explanation of symbols]

 1 Differential Gear Case 2 Case Body 2a Flange 2b Inner Surface 3 Lid 3a Flange 9 Side Gear 10 Side Gear 13 Working Chamber 17 Inner Plate (Inner Plate Set) 20 Retainer 21 Engagement Support Part 22 Flange Part 23 Bolt Insertion Hole 24 Seal Convex portion 25 engaging protrusion 26 outer plate (outer plate group) 27 taper portion 28 seal portion 100 differential gear unit

Claims (2)

[Claims] 1. A differential gear case that is driven and rotated around coaxial axes of a first output shaft and a second output shaft, and a differential gear case that is rotatably housed in the differential gear case and has a first output shaft and a second output shaft. 1
And differential gear means having first and second transmission members that rotate integrally with the second output shaft and that are differentially rotatable with respect to each other; a working chamber in which a viscous fluid is sealed; An outer plate set that engages with the differential gear case in the rotational direction, and an inner plate set that is alternately arranged in the working chamber and that engages with the second transmission member in the rotational direction. A differential gear device including differential limiting means, wherein the differential gear case has a bowl-shaped case body and a lid body that is flange-coupled to close an opening of the case body, and The plate mounting member including an engagement support portion that engages with the outer plate set in a non-rotatable manner and a flange portion that is sandwiched and fixed to the flange coupling portion of the case body and the lid body is the outer plate. Differential gear unit, characterized in that engaging in the rotational direction over Efforts to said differential gear case. 2. The flange portion of the plate mounting member is provided with an elastically deformable sealing portion projecting over the entire circumference of the flange so as to liquid-tightly seal the viscous fluid in the working chamber. The differential gear unit according to claim 1.