JP2000291778A - Differential limitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stable differential limitting force and improve a durability by enlarging the slide-contact area of a slide surface. SOLUTION: This device is composed of a pair of pinion gears 2, 3 stored in the pocket of a differential case 1 and meshed with each other, a pair of right/left side gears 4, 5 coaxial with the rotary shaft of the differential case meshed by a bevel gear with the either one of them respectively and right/left output shafts 9, 10 connected to the inner periphery of these respective side gears 4, 5 respectively. By extending the inner diameter of the slide surface mutually facing to a pair of side gears 4, 5 upto the axial center side from the outer diameter of the output shaft, the slide-contact area of the slide surface is enlarged and the surface pressure is also minified and the durability is improved and a stable differential operation and differential restriction operation can be carried out under Rt with a few change.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a pair of pinion gears housed in a pocket of a differential case and meshing with each other, and a pair of left and right side gears coaxial with the rotation shaft of the differential case respectively meshing with one of them. To a differential limiting device.

[0002]

2. Description of the Related Art A differential limiting device of this type is composed of a pair of pinion gears housed in a pocket of a differential case and meshing with each other, and a pair of left and right side gears coaxial with the rotation shaft of the differential case meshing with one of them. A typical example is disclosed in Japanese Patent Application Laid-Open No. 8-247261 shown in FIG.
This is housed in a pocket of the differential case 20 in which the left and right differential cases 20A and 20B are connected, and has a pair of meshing pinion short gears (not shown) and pinion long gears 2 having a rotation axis parallel to the rotation axis of the differential case.
2 and left and right side gears 24, 25 coaxial with the rotation axis of the differential case 20 meshing with either one of them.
(Tooth portion 22B of pinion long gear 22 meshes with tooth portion 25A of right side gear 25, and tooth portion of pinion short gear (not shown) and left side gear 2).
4 is meshed with the tooth portion 24A).
A thrust block 26 is interposed between the left and right side gears 4 and 25 so as to abut the inner ends of the left and right output shafts (not shown) fitted to the inner circumferences of the left and right side gears 24 and 25 by spline fitting or the like. It was done.

In the differential limiting device having such a configuration, when one of the left and right drive wheels connected to the left and right output wheels connected to the left and right side gears 24 and 25 by spline fitting or the like slightly slips. In addition, the outer peripheral surface of the tooth tip of the pinion gear is caused to be differential by a meshing reaction force generated by the helical meshing between the pair of pinion gears and the side gears 24 and 25 on the idling drive side between the pair of pinion gears and the side gears 24 and 25. While being pressed against the inner peripheral surface of the pocket, the side gear on the idling side is pressed against the inner wall surface of the differential case via the side washer provided on the back to brake,
The limited driving force is transferred to the stationary driving wheels, and the differential action of the helical differential device is limited, thereby escaping from a rough road such as muddy land. A center washer 28 is provided on the outer periphery of the thrust block 26 between the left and right side gears 24 and 25.
4 and 25 are slidably contacted so that they do not separate from each other, or are strongly slidably contacted when pressed during coasting. In the case where a disc spring or the like as a preload applying member is interposed as the center washer 28, the center washer 28 also has a differential limiting function by generating an initial torque.

[0004]

However, the sliding surface between the side gears 24 and 25 on which the center washer 28 is interposed is located at the outer peripheral portion of the thrust block 26, and thus has a relatively large diameter. However, the contact area was restricted, the surface pressure was high, the centering function was not sufficient, and the peripheral speed during sliding contact tended to be high. Therefore, the distribution ratio (transfer ratio: Rt) of the generated differential limiting force to the left and right side gears is not stable, and the change may be large. Further, when a disc spring or the like capable of applying a preload is installed as the center washer 28 provided on the sliding surface, the spring load, that is, the initial torque characteristic is also restricted.

Therefore, in the present invention, the above-described differential limiting device is further improved to obtain a stable differential limiting force by enlarging the sliding area of the sliding surface, and to further improve the durability of the differential limiting device. It is intended to provide a device.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a pair of pinion gears housed in a pocket of a differential case and meshing with each other, and a pair of left and right side gears coaxial with the rotation shaft of the differential case respectively meshing with one of them. And a left and right output shaft respectively connected to the inner periphery of each of the side gears, wherein the inner diameter of the sliding surfaces of the pair of side gears facing each other is from the outer diameter of the output shaft to the axis side. It is characterized by being extended. The present invention also provides a pair of pinion gears housed in a pocket of a differential case and meshing with each other, a pair of left and right side gears coaxial with a rotation shaft of the differential case respectively meshing with any one of them, and an inner periphery of each of these side gears. In a differential limiting device including left and right output shafts connected to each other, an inner diameter of a sliding member disposed between the pair of side gears is extended from an outer diameter of the output shaft to an axis side. It is assumed that. Further, the invention is characterized in that the sliding member is configured to apply a thrust force to a side gear. Further, the present invention is characterized in that the centering of the sliding member is performed at an axis, and these are used as means for solving the problems.

[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. FIG. 1 is an overall sectional view showing a first embodiment of a differential limiting device according to the present invention. FIG.
As shown in FIG. 1, the differential limiting device according to the present invention includes, for example, a right differential case 1 closed like a lid by a left differential case 1A.
B, a pair of pinion long gears 2 and a pinion short gear 3 (see FIG. 3 for the pinion short gear 3) meshing with each other in a pair of pockets extending in the axial direction parallel to the rotation axis of the differential case 1 and drilled. What is drawn below relates to another combination of a plurality of pairs.In practice, a pair of pinion short gears and pinion long gears are arranged adjacent to and mesh with each other, for example, four pairs, a circle. Are arranged at equal intervals on the circumference) and are housed in a floating state, and are constituted by left and right side gears 4 and 5 coaxial with the rotation shaft of the differential case 1 meshing with one of them. In the illustrated example, the second pinion long gear 2
The teeth 2B mesh with the teeth 5A of the right side gear 5, the teeth 3A of the pinion short gear 3 mesh with the teeth 4A of the left side gear 4, and the first teeth 2A of the pinion long gear 2.
And the tooth portion 3A of the pinion short gear 3 mesh with each other. Further, left and right output shafts (not shown) are provided on the inner periphery of each of the side gears 4 and 5 (see 9 and 10 in FIG. 4).
Are inserted and connected by spline fitting or the like.

The most characteristic point of the present invention is that, in a differential limiting device including left and right output shafts connected to the inner periphery of each of the side gears, the inner diameter of the sliding surfaces of the pair of side gears facing each other. Are extended from the outer diameter of the output shaft to the axial center side. The opposed surfaces of the left and right side gears 4 and 5 are configured to have bottoms, and the left and right An abutment portion of the output shaft is formed, and these opposed sliding surfaces are configured to be in sliding contact with each other. Centering protrusions and recesses as in the embodiment described later may be formed on the sliding surfaces of the left and right side gears 4 and 5 facing each other. Also, left and right side washers 11, 12 are interposed between the back surfaces of the side gears 4, 5 and the inner wall surfaces of the left and right differential cases 1A, 1B, and the thrust force generated by the meshing reaction force of the differential gears. Responsible for friction when braking each side gear. The differential gear of the present invention is not limited to the helical type in which the axis of the pinion gear and the axis of the side gear are parallel as described above, and the differential gear of the worm type in which the axis of the pinion gear and the axis of the side gear are orthogonal to each other. It goes without saying that the present invention can be applied to a motion limiting device.

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 2 and pinion short gears arranged in a pocket of the differential case 1. 3 and
Any one of these gears is appropriately differentially distributed by a differential action with a pair of left and right side gears 4 and 5 that mesh with each other and transmitted to the left and right side gears 4 and 5, that is, the left and right drive wheels. 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 move between the pinion gears 2 and 3 and the pockets, and the rear surfaces of the side gears 4 and 5 and the inner wall surface of the differential case 1. Are locked together by the differential limiting force via the side washers 11 and 12 generated between them, and the driving force is transmitted strongly.

When one of the left and right drive wheels slips lightly, the other drive wheel in the differential device idles and the helical teeth on the idle drive side between the pair of pinion gears and the side gears 4 and 5 are rotated. Due to the meshing reaction force generated by the meshing, 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 idle side gear is pressed against the inner wall surface of the differential case via a side washer provided on the back surface. Then, the limited driving force is transferred to the stationary driving wheels, and the differential action of the differential device is limited, thereby escaping from a rough road such as muddy land. The sliding surface between the left and right side gears 4 and 5 is slidably contacted so that the side gears 4 and 5 do not separate from each other and strongly slidably pressed during coasting. The opposing sliding surfaces between 4 and 5 have the inner diameter sufficiently extended from the outer diameter of the output shaft to the shaft center side.
The sliding contact area is large, the surface pressure is small, and the portion where the peripheral speed of the sliding contact is low occupies a large portion, and the durability is improved.

FIG. 2 is an overall sectional view showing a second embodiment of the differential limiter according to the present invention. In the second embodiment, similarly to the first embodiment, the opposing surfaces of the left and right side gears 4 and 5 are configured to have bottoms, and the left and right output shafts fitted to these are set. The inner surface of the sliding member 8 disposed between the pair of side gears 4 and 5 is extended from the outer diameter of the output shafts (9 and 10) to the axial center side. And As the sliding member 8, a center washer or a disc spring as a preload applying member is employed. The sliding member 8 is fitted to a centering projection 4B formed on the axis of one of the opposed end surfaces of the left and right side gears 4 and 5 (the left side gear 4 in the illustrated example) to perform centering. In this embodiment, it is needless to say that a centering recess for receiving the centering projection 4B may be formed on the opposite end face of the right side gear 5. Thus, in the present embodiment, the thrust block and the like can be eliminated, and the configuration is simplified.

FIG. 3 is an overall sectional view showing a third embodiment of the differential limiter according to the present invention. In the present embodiment, axially divided thrust blocks 6, 7 are interposed between opposed end faces of the left and right side gears 4, 5,
A sliding member 8 is provided between the divided thrust blocks 6 and 7. Since the inner diameter of the sliding member 8 is sufficiently extended from the outer diameter of the output shaft to the axial center side,
A large sliding contact area as the sliding member 8 having the center washer function can be obtained. The sliding member 8 is fitted to a centering projection 6A formed on the axis of one of the divided end faces of the thrust blocks 6 and 7 (in the illustrated example, the thrust block 6) to perform centering. It goes without saying that a centering recess for receiving the centering projection 6A may be formed in the other end face of the thrust block, as in the example of FIG. 4 described later.

Left and right side washers 11, 12 are interposed between inner surfaces of left and right differential cases 1A, 1B on rear surfaces of the side gears 4, 5, and are generated by a meshing reaction force of a differential gear. It receives the thrust force or the friction when braking each side gear by receiving the initial torque when a disc spring or the like having a preload applying function is employed as the sliding member 8 as described later. Further, in the present invention, as described above, for example, a disc spring may be interposed as the sliding member 8 so as to apply the initial torque for limiting the differential to the side gears 4 and 5 by applying a preload. .

Thus, the rotational driving force transmitted to the differential case 1 is transmitted to one of the pair of mutually meshing pinion long gears 2 and the pinion short gears 3 arranged in the pocket of the differential case 1. The gears are appropriately differentially distributed by the differential action between the pair of left and right side gears 4 and 5 that mesh with each other, and
That is, it is transmitted to the left and right drive wheels. 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 move between the pinion gears 2 and 3 and the pockets, and the rear surfaces of the side gears 4 and 5 and the differential case 1
When one of the left and right driving wheels slips lightly, the driving force is transmitted strongly by the differential limiting force via the side washers 11 and 12 generated between the inner wheel and the left and right driving wheels. The pair of pinion gears and side gears 4 running idle with respect to the other drive wheel in the driving device;
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 by the meshing reaction force generated by the helical meshing of the idling drive side between the wheels 5, and the side gear on the idling side is interposed on the back surface. By pressing the inner wall of the differential case via a washer to apply braking, the limited driving force is transferred to the driving wheels on the stationary side, and the differential action of the differential device is limited. Escape from is made.

The sliding member 8 includes left and right side gears 4,
5, the side gears 4, 5 are in sliding contact with each other to such an extent that they do not separate from each other, and are strongly slid in contact with each other via the divided thrust blocks 6, 7 during pressing during coasting. 8 is that the inner diameter is sufficiently extended from the outer diameter of the output shaft to the axial center side, so that the sliding contact area is large and the surface pressure is small, and the peripheral speed of the sliding contact is occupied mostly by a small portion. And the durability is improved. In addition, since the centering is performed by fitting into the centering projection formed on one of the axial ends of the opposed end faces of the divided thrust blocks 6 and 7, the torque distribution of the differential and the differential limiting force is disturbed. Stable differential action and differential limiting action can be performed under Rt with little change without occurrence. In the case where a disc spring or the like as a preload applying member is interposed as the center washer 8, the preload applying member having a large sliding contact area and a small surface pressure, and a well-centered preload applying member has a wide width of the initial. In addition to being able to set the torque, stable differential limiting action can be performed with high durability.

FIG. 4 is an overall sectional view showing a fourth embodiment of the differential limiter according to the present invention. In the present embodiment, unlike the two examples described above, the left and right output shafts 9, 10 fitted by splines or the like to the inner periphery of the left and right side gears 4, 5 are configured to abut each other. A sliding member 8 as a preload applying member such as a center washer or a disc spring is interposed between opposed end surfaces of the shafts 9 and 10. The sliding member 8 is fitted to a centering protrusion 9A formed on the axis of one of the output shafts 9 and 10 (the left output shaft 9 in the illustrated example) to perform centering. In the present embodiment, a centering recess 10A for receiving the centering protrusion 9A is formed on the opposite end face of the right output shaft 10, but the centering protrusion 9A is formed.
A can be made substantially equal to the thickness of the sliding member 8, and the centering recess 10A can be omitted. Thus, in the present embodiment, members such as the thrust block can be omitted, and it is only necessary to form a straight inner peripheral hole having a spline groove in the side gear, which simplifies the configuration and facilitates manufacture.

The embodiments of the present invention have been described above. However, within the scope of the present invention, the shapes of the pinion short gear and the pinion long gear and the meshing forms thereof, the number of pairs thereof, the sliding Shapes and materials of members, shapes of thrust blocks, shapes of left and right side gears and their arrangements, shapes of output shafts, forms of centering of thrust blocks, side gears and output shafts on sliding members, sliding as preload applying members Appropriate ones can be adopted for the shape of the moving member, the mounting mode of the pinion gear and the side gear to the differential case, the type of the differential device, and the like.

[0018]

As described above in detail, the present invention relates to a pair of pinion gears housed in a pocket of a differential case and meshing with each other, and coaxial with the rotation shaft of the differential case meshing with one of these. In a differential limiting device including a pair of left and right side gears and left and right output shafts respectively connected to the inner periphery of each side gear,
The sliding surfaces of the pair of side gears that are opposed to each other are extended from the outer diameter of the output shaft to the axial center side, so that the sliding surfaces of the opposed sliding surfaces between the side gears are large and the surface pressure is small. In addition, a portion where the peripheral speed of the sliding contact is small occupies a large portion, and the durability is improved. Further, when the inner diameter of the sliding member disposed between the pair of side gears is extended from the outer diameter of the output shaft to the axis side, the sliding contact area as the sliding member having the center washer function is increased. The sliding surface has a large sliding contact area and a small surface pressure, and a portion where the peripheral speed of the sliding contact is low occupies a large portion, thereby improving the durability of the sliding member.

Further, since the centering of the sliding member is performed at the center of the axis, the sliding member has a sliding contact surface between the opposed end faces of the divided thrust block and between the left and right side gears. Since the centering is performed by fitting to the centering projection formed on the shaft center between the opposed surfaces of the output shafts on the right and left sides, the torque distribution of the differential and the differential limiting force is not disturbed. A stable differential action and a differential limiting action can be performed under a small Rt. Also, when the sliding member is configured to apply a thrust force to the side gear, the sliding contact area is large, the surface pressure is small, and the pre-load applying member that is well centered has a wide width of the internal pressure. In addition to being able to set the torque, stable differential limiting action can be performed with high durability. As described above, according to the present invention, there is provided a differential limiting device in which the sliding contact area of the sliding surface is increased to obtain a stable differential limiting force and the durability is further improved.

[Brief description of the drawings]

FIG. 1 is an overall sectional view showing a first embodiment of a differential limiting apparatus according to the present invention.

FIG. 2 is an overall sectional view showing a second embodiment of the differential limiting apparatus according to the present invention.

FIG. 3 is an overall sectional view showing a third embodiment of the differential limiting device according to the present invention.

FIG. 4 is an overall sectional view showing a fourth embodiment of the differential limiting device of the present invention.

FIG. 5 is an overall cross-sectional view showing a differential limiting device as the background of the present invention.

[Explanation of symbols]

 Reference Signs List 1 differential case 1A left differential case 1B right differential case 2 pinion long gear 2A first tooth portion 2B second tooth portion 3 pinion short gear 3A tooth portion 4 left side gear 4A tooth portion 4B centering projection 5 right side gear 5A tooth portion 6 left thrust block 6A centering Projection 7 Right thrust block 8 Sliding member (center washer, disc spring) 9 Left output shaft 9A Centering projection 10 Right output shaft 10A Centering recess 11 Left side washer 12 Right side washer

Claims (4)

[Claims] 1. A pair of pinion gears housed in a pocket of a differential case and meshing with each other, a pair of left and right side gears coaxial with a rotation shaft of the differential case respectively meshing with one of them, and an inner periphery of each of these side gears. In a differential limiting device including left and right output shafts connected to each other, an inner diameter of a sliding surface of the pair of side gears facing each other is extended to an axial center side from an outer diameter of the output shaft. Differential limiter. 2. A pair of pinion gears housed in a pocket of a differential case and meshing with each other, a pair of left and right side gears coaxial with a rotation shaft of the differential case respectively meshing with one of them, and an inner periphery of each of these side gears. In a differential limiting device including left and right output shafts connected to each other, an inner diameter of a sliding member disposed between the pair of side gears is extended from an outer diameter of the output shaft to an axis side. Differential limiting device. 3. The apparatus according to claim 2, wherein the sliding member is configured to apply a thrust force to a side gear.
4. The differential limiting device according to claim 1. 4. The differential limiting device according to claim 2, wherein a centering of the sliding member is performed at an axis.