JP2002081525A - Differential limiting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a differential limiting device enabling forced circulation in a differential case sealed by a sealed easing, and removal of abrasion powder, etc. SOLUTION: In a parallel axis type sealed differential device provided with the differential case 1B sealed by the sealed easing 2, at least one discharge passage 8A is provided from a gear pocket 3 of the differential case 1B containing a pair of pinion gears 4 and 5 meshed with each other to compose a differential gear, and a circulation passage 9A is provided to be communicated with the inside and the outside of the differential case 1B. By pump action generated by rotation of the pinion gears 4 and 5 in the gear pocket 3 during differential action, lubricating oil around the pinion gears 4 and 5 is discharged through the discharge passage 8A out of the differential case 1B. Lubricating oil filled in a sealed space 10 outside the differential case 1B is thus forcedly circulated through the circulation passage 9A into the differential case 1B, thereby engagement parts, etc., in the differential gear can be effectively lubricated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parallel shaft type sealed differential device having a differential case sealed by a sealed casing.

[0002]

2. Description of the Related Art A parallel shaft type differential limiting device is lightweight and has a high performance because a pair of pinion gears meshing with each other and constituting a differential gear can be arranged adjacent to each other in the circumferential direction to make the bulk in the radial direction compact. It has come to be frequently used as a differential limiting device. FIG. 4 shows a typical example of such a parallel shaft type differential limiting device, which is disclosed in Japanese Patent Application Laid-Open No. 3-37455. This is a pair of pinion gears 104 and 105 that are housed in the gear pocket 113 of the differential case 101 and have a rotation axis parallel to the rotation axis of the differential case 101, and the rotation of the differential case 20 that meshes with one of them. It is composed of left and right side gears 103 and 111 coaxial with the shaft.

In the differential limiting device constructed as described above, in order to lubricate each meshing portion of the pinion gear and the side gear constituting these differential gears, the gearbox 113 in which the pinion gears 104 and 105 are stored is moved out of the differential case 101. Are provided with lubrication holes 114 communicating with the lubrication holes. Through this lubrication hole 114, the differential case 1
The lubricating oil stored in an external carrier or the like during the rotation of the motor 01 rotates the lubrication of each of the meshing portions.

[0004]

However, the lubrication holes 11 provided in such a conventional differential case 101 are not provided.
No. 4 lubricates the lubricating oil stored in a carrier or the like outside the differential case 101 by utilizing the rotation of the differential case 101, and does not provide sufficient lubrication performance.

Accordingly, an object of the present invention is to provide a differential limiting device that enables forced circulation in a differential case sealed by a sealed casing and also enables removal of wear powder and the like.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a parallel shaft type sealed differential device having a differential case sealed by a sealed casing, wherein the differential case comprises a pair of pinion gears which constitute a differential gear and mesh with each other. And at least one discharge path is provided from the gear pocket, and a return path communicating with the inside and outside of the differential case is provided. Further, the present invention is characterized in that the discharge path is provided so as to correspond to a meshing portion of a pair of pinion gears housed in a gear pocket. Further, the present invention is characterized in that a filter is provided in the return passage, and these are used as means for solving the problem.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a differential limiting device according to an embodiment of the present invention. 1 and 2 show a first embodiment of a differential limiting device according to the present invention. FIG. 1 is a cross-sectional view of a main part, which is a cross-sectional view taken along line AA of FIG. 2, and FIG. It is BB sectional drawing of FIG. As shown in FIG. 1, the differential limiting device of the present invention is a parallel shaft type sealed differential device having a differential case 1 sealed by a sealed casing 2. 5 and at least one discharge path 8A is provided from the gear pocket 3 of the differential case 1
A recirculation passage 9A communicating with the inside and outside of the differential case 1 is provided.

More specifically, as shown in FIG. 2, the right differential case 1 closed in a lid shape by the left differential case 1A.
B, a pinion long gear 4 and a pinion short gear 5 meshing with each other in a gear pocket 3 extending in the axial direction parallel to the rotation axis of the differential case 1 (for convenience, FIG. The meshing state is drawn in a dash-dot line. The meshing state is shown in FIG. 1), and is stored in a floating state. In the example of FIG.
They are arranged at equal intervals on the circumference of the set. And, it is composed of left and right side gears 6, 7 coaxial with the rotation shaft of the differential case 1 meshing with either one of them. In the illustrated example, the second tooth portion 4B of the pinion long gear 4 meshes with the tooth portion 7A of the right side gear 7, the tooth portion 5A of the pinion short gear 5 meshes with the tooth portion 6A of the left side gear 6, and the pinion The first teeth 4A of the long gear 4 and the teeth 5A of the pinion short gear 5 mesh with each other. further,
Left and right output shafts (not shown) are inserted and connected to the inner periphery of each of the side gears 6 and 7 by spline fitting or the like.

The most characteristic point of the present invention is that the differential case 1 (the right differential case 1B in the illustrated example) is sealed by a sealing casing 2 with an appropriate sealing ring or the like, and a gap between the outside of the differential case 1B and the sealing casing 2 is provided. Preferably, in a differential limiting device having a sealed space 10 preferably filled with lubricating oil, at least one discharge passage 8A is provided from a gear pocket 3 of the differential case 1B accommodating a pair of pinion gears 4, 5. , A return path 9A communicating with the inside and outside of the differential case 1B.

The operation of such a differential limiting device will be described. The rotational driving force transmitted to the differential case 1 is applied to a pair of mutually meshing pinion long gears 4 and a pinion long gear 4 disposed in the gear pocket 3 of the differential case 1B. The short gear 5 and a pair of left and right side gears 6, 7 meshing with one of the short gears 5 are appropriately differentially distributed by a differential action and transmitted to the left and right side gears 6, 7, that is, to the left and right drive wheels. Is done. During normal straight running, the differential unit is integrated without performing a differential action and transmits the driving force to the left and right drive wheels. At this time, the driving force on the differential case side with respect to the driving resistance of the wheels causes the meshing reaction force between the differential gears to generate a force between the pinion gears 4 and 5 and the peripheral surface of the gear pocket 3 and the rear surfaces of the side gears 6 and 7 to The driving force is transmitted strongly by being locked together by the differential limiting force generated between the inner wall surface and the like of 1B.

When one of the left and right drive wheels slips lightly, the other drive wheel in the differential device idles, and the idle drive side helical meshing between the pair of pinion gears and the side gears. Due to the generated meshing reaction force, the outer peripheral surface of the tooth tip of the pinion gear is pressed against the inner peripheral surface of the pocket of the differential case, and the idling side gear is pressed against the inner wall surface of the differential case via a side washer provided on the back surface to apply braking. As a result, the limited driving force is transferred to the stationary drive wheels, and the differential action of the differential device is limited, thereby escaping from a rough road such as muddy land.

While such a differential operation is being performed, the lubricating oil around the pinion gear is discharged out of the differential case 1B through the discharge passages 8A and 8B due to the pump action generated by the rotation of the pinion gear in the gear pocket 3.
At the same time, the lubricating oil filling the sealed space 10 is forcibly recirculated into the differential case 1B through the recirculation paths 9A and 9B. A filter 11 is interposed in the return passages 9A and 9B, and abrasion powder and the like generated at each meshing portion of the differential gear are removed when the lubricating oil is returned.

FIG. 3 shows a second embodiment of the differential limiter according to the present invention, and is a cross-sectional view taken along line A'-A 'of FIG. In this embodiment, the discharge path 8B communicating from the gear pocket 3 to the outside of the differential case 1B is
The pinion gears 4 and 5 are accommodated in a pair of gears. As a result, a high discharge pressure of the lubricating oil can be obtained by the gear pump action at the meshing portion of the pair of pinion gears 4 and 5 meshing in the gear pocket 3, and the lubricating oil circulation efficiency can be improved.

The embodiments of the present invention have been described above. However, within the scope of the present invention, the shapes of the pinion short gears and the pinion long gears, the meshing forms thereof, the number of pairs thereof, the right and left The shapes of the side gears and their arrangement, the shape of the output shaft, the pinion gears and the form of attachment to the differential case of the side gears, the shape of the sealed casing and its sealing form in the differential case, the shape, number, and arrangement position of the discharge path and the return path, Appropriate ones can be adopted for the shape and type of the filter and the mode of interposing the filter in the return path.

[0015]

As described above in detail, according to the present invention, in a parallel shaft type sealed differential having a differential case sealed by a sealed casing, a pair of pinion gears meshing with each other by forming a differential gear are provided. By providing at least one discharge path from a gear pocket of the accommodated differential case and providing a return path communicating with the inside and outside of the differential case, the pinion gear is rotated by the rotation of the pinion gear in the gear pocket during the differential operation. Since the surrounding lubricating oil is discharged out of the differential case through the discharge path, the lubricating oil filled in the sealed space outside the differential case is forcibly recirculated into the differential case through the recirculation path, so that each meshing portion of the differential gear and the like are disengaged. Effectively lubricated.

In the case where the discharge path is provided so as to correspond to the meshing portion of the pair of pinion gears housed in the gear pocket, the lubricating oil is formed by the gear pump action at the meshing portion of the pair of pinion gears meshing in the gear pocket. A high discharge pressure can be obtained and the lubricating oil circulation efficiency can be improved, and the circulation function can be effectively exerted even when a filter is provided in the return path described later. Further, when a filter is interposed in the return passage, wear powder and the like generated at each meshing portion of the differential gear is removed at the time of return of the lubricating oil, so that the wear powder and the like are not brought into the differential case. As described above, according to the present invention, there is provided a differential limiting device capable of forcibly circulating in a differential case sealed by a sealed casing and also capable of removing abrasion powder and the like.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of a differential limiting device according to the present invention, and is a cross-sectional view taken along line AA of FIG.

FIG. 2 is an overall vertical sectional view of the same, and is a BB sectional view of FIG. 1;

FIG. 3 shows a second embodiment of the differential limiting device according to the present invention, and is a cross-sectional view taken along the line A′-A ′ of FIG.

FIG. 4 is a cross-sectional and vertical sectional view of a conventional differential limiting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Differential case 1A Left differential case 1B Right differential case 2 Sealed casing 3 Gear pocket 4 Pinion long gear 4A 1st tooth part 4B 2nd tooth part 5 Pinion short gear 5A tooth part 6 Left side gear 6A tooth part 7 Right side gear 7A tooth part 8A Discharge path 8B Discharge path 9A Reflux path 9B Reflux path 10 Sealed space 11 Filter

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16H 57/04 F16H 1/45

Claims (3)

[Claims] 1. A parallel shaft type sealed differential having a differential case sealed by a sealed casing, wherein at least one discharge path is formed from a gear pocket of the differential case, which constitutes a differential gear and accommodates a pair of pinion gears meshing with each other. And a return path communicating with the inside and outside of the differential case is provided. 2. The differential limiting device according to claim 1, wherein said discharge path is provided corresponding to a meshing portion of a pair of pinion gears housed in a gear pocket. 3. The differential limiting device according to claim 1, wherein a filter is provided in the return path.