JPH11294560A - Differential limiter - Google Patents

Abstract

(57) [Problem] To provide a differential limiting device employing an initial torque generating component that does not generate abnormal noise and can always obtain a stable differential limiting torque under a high differential limiting action. The purpose is to: A rotational driving force of a differential case (1) is distributed to left and right side gears (4, 5) disposed on a rotational shaft of the differential case (1) via pinion gears (2, 3) rotatably supported or housed in the differential case (1). A differential limiting device that obtains a differential limiting force by braking between relative rotating portions of a differential device that transmits a braking force by applying a predetermined interference between the relative rotating portions and interposing an elastic body 8 to provide a braking force To generate an initial torque so that the vehicle can quickly escape on a bad road or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential limiting device for transmitting the rotational driving force of a differential case to left and right side gears disposed on the rotation shaft of the differential case through a pinion gear or the like in the differential case. In particular, relates to an initial torque generating member.

[0002]

2. Description of the Related Art A differential limiting device which obtains a differential limiting force by braking between relative rotating portions of a differential device comprising a pinion gear or the like of this type is disclosed, for example, in European Patent No. 130 shown in FIG.
There is a differential limiting device as disclosed in U.S. Pat. This conventional example is called a helical pinion type differential limiter, and the rotational driving force of the differential case 303 is applied to the differential case 30.
The left and right side gears 311 and 313 disposed on the rotation shaft of the differential case 303 via a plurality of sets of a pair of helical gear-type pinion gears 331 and 333 stored in the three cylindrical recesses 325 and 327, respectively. The torque is distributed and transmitted by the dynamic meshing, and the meshing thrust force from the helical gear-type pinion gears 331 and 333 generated by the relatively large driving resistance at the time of the differential causes the end face of the helical gear-type pinion gear and the differential case side wall. This is a differential limiting device that performs a differential limiting operation by a frictional resistance with an inner surface. When the differential is limited, the helical gear type pinion gears 331, 33
3 and the left and right side gears 311 and 313 in addition to the thrust force generated by the meshing reaction force between the left and right side gears 311 and 313.
Some disc springs 32 are provided between springs 313 via spring seats.
1 to generate a constant amount of thrust force, that is, an initial torque, so as to ensure the generation of a predetermined differential limiting force. Thus, even with a small differential unbalanced driving resistance. It is configured to be able to escape on a bad road.

[0003]

However, when a disc spring is interposed between left and right side gears 311 and 313 which are relative rotating parts as seen in the above-mentioned prior art, the sliding contact surface of the disc spring is in line contact. Therefore, the differential limiting torque generated as the initial torque may be unstable or generate abnormal noise. In addition, in the initial torque generating structure of these conventional devices, only the differential limiting force of only a predetermined initial torque can be obtained, and the appearance of an initial torque generating structure capable of exhibiting a higher differential limiting effect has been desired. .

Accordingly, the present invention solves the above-mentioned problems in the conventional differential limiting device, and provides an initial in which no abnormal noise is generated and a stable differential limiting torque can always be obtained under a high differential limiting action. An object of the present invention is to provide a differential limiting device employing a torque generating component.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a torque distribution device for distributing the rotational driving force of a differential case to left and right side gears disposed on the rotational shaft of the differential case via a pinion gear supported or accommodated in the differential case. In a differential limiting device that obtains a differential limiting force by braking between relative rotating portions of a differential device that transmits and transmits a differential torque, a predetermined interference is provided between the relative rotating portions, and an elastic body is interposed between the relative rotating portions to set an initial torque. Is generated.
Further, the present invention is characterized in that a viscous fluid is sealed between the relative rotation parts adjacent to the elastic body. Further, the present invention is characterized in that the elastic body for giving the relative rotation portion a predetermined interference is constituted by a spring member and a seal member. Further, the present invention is characterized in that at least one of the relative rotating parts in which the viscous fluid is sealed, a large number of irregularities capable of imparting shear resistance to the viscous fluid are formed, and these are solved. Means.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show an embodiment of a differential limiting device according to the present invention. FIG. 1 is an overall sectional view of a helical pinion type differential limiting device, FIG. 2 is an enlarged view of a portion A in FIG. It is the B sectional view. The initial torque generating device of the present invention is used for distributing the rotational driving force of the differential case to the left and right side gears disposed on the rotational shaft of the differential case via a pinion gear supported or housed in the differential case. A differential limiting device that obtains a differential limiting force by braking between the relative rotating portions of the differential device that transmits the differential transmission. In the present embodiment, a helical pinion type differential limiting device, Although this is an example of a differential limiting device employing a helical gear type pinion gear, it is needless to say that the present invention can be applied to a differential limiting device employing a spur gear type pinion gear or a differential limiting device employing a bevel gear type pinion gear. In the present embodiment, the helical gear type pinion gears 2 and 3 (FIG. 1)
A right differential case 1B accommodating the left and right side gears 4, 5 and the like, and a lid-like left differential case 1A is fitted and fastened to the open side of the case by a fixing bolt or the like. The pair of helical gear-type pinion gears 2 and 3 include a double-toothed pinion gear 2 having two left teeth 2A and right teeth 2B, one of which is axially separated, and a single-tooth pinion gear 3 having the other tooth 3A. And one tooth 2 of the compound tooth pinion gear 2
B meshes with the teeth 5A of the right side gear 5 and the other teeth 2
A forms a differential device in which A meshes with the teeth 4A of the left side gear 4 through meshing with the teeth 3A of the single tooth pinion gear 3.

The present invention relates to such a differential device,
An initial torque is generated by providing an elastic body 8 with a predetermined interference between the relative rotating parts. In the present embodiment, the left and right differential cases 1A and 1B and the left and right side gears 4, which are relative rotating parts,
An initial torque is generated by providing a predetermined interference between the elastic members 5 and interposing the elastic body 8 therebetween. In the present embodiment, the left and right differential cases 1A, 1A
B, left differential case 1A formed to fit with each other
A predetermined interference is provided between the inner and outer circumferences of the case cylindrical portion 1C and the small diameter boss portion 4C of the left side gear 4, and between the inner and outer circumferences of the cylindrical portion 1D of the right differential case 1B and the small diameter boss portion 5C of the right side gear 5. The elastic body 8 is interposed. Reference numeral 7 denotes a thrust washer.

As shown in FIG. 2, which is an enlarged view of a portion A in FIG. 1, in the present embodiment, the elastic body 8 having a predetermined interference in the relative rotation portion is provided on the left side gear 4 side. To explain with an example (similarly on the right side gear 5 side), a spring member 8A made of metal or the like and having a U-shaped cross section pressed against the case cylinder 1C of the left differential case 1A by surface contact, and the spring member 8
A seal member 8B having an X-shaped cross section is pressed by A to the outer peripheral surface of the small diameter boss portion 4C of the left side gear 4.
Each end portion of the seal member 8B having the X-shaped cross section comes into contact with a relative rotating portion with which it comes into contact by surface contact. The spring member 8A and the seal member 8B may be formed so that their dimensions themselves are within a tolerance to which a tightening allowance for pressing against the relative rotation member with which they are in sliding contact is provided. May be configured so that the interference is given. A synergistic interference of both of them may be formed. Such elastic bodies 8 are provided at two locations on the outer peripheral surface of the small diameter boss portion 4C of the left side gear 4. Also,
These spring member 8A and seal member 8B can be configured such that the inside and outside arrangement positions are reversed as long as sealing of a viscous fluid described later is not impaired. The sealing member 8B
In addition to generating a differential limiting torque as an initial torque, a sealing effect of a viscous fluid, which will be described later, can be effectively performed.

Further, the present invention is characterized in that a viscous fluid 9 is sealed between the relative rotating parts adjacent to the elastic body 8 as shown in FIG. Between the elastic bodies 8, 8 installed at an axial interval, between the inner and outer peripheries of the case cylinder portion 1C of the left differential case 1A and the small diameter boss portion 4C of the left side gear 4, which are relative rotating parts (the right differential case 1B A predetermined gap is formed between the inner and outer circumferences of the right side gear 5 and the small-diameter boss portion 5C), and a viscous fluid 9 such as silicone oil is sealed in the gap between the inner and outer circumferences. The viscous fluid 9 is provided in at least one of the relative rotating portions where the viscous fluid 9 is sealed.
A large number of irregularities capable of effectively imparting shear resistance to the substrate. In the illustrated example, a large number of irregularities 10, 10 are formed both on the inner peripheral side of the case cylinder 1C and on the outer peripheral side of the small diameter boss 4C of the left side gear 4. In the elastic body 8 in the above-described embodiment, in the illustrated example, a housing recess 1E for the elastic body 8 is formed on the inner periphery of the case cylinder 1C of the left differential case 1A, which is a relative rotating part. The storage recess may be formed on the small diameter boss 4C side of the left side gear 4, or these recesses may not be formed.

When the initial torque generating member of the present invention is employed in a helical pinion type differential limiting device as in the above embodiment, the rotational driving force of the differential case 1 is set in the cylindrical recess of the differential case 1 respectively. Torque is distributed and transmitted by differentially meshing with left and right side gears 4, 5 arranged on the rotation shaft of the differential case 1 via a plurality of pairs of stored helical gear type pinion gears 2, 3. The frictional resistance between the end surface of the helical gear type pinion gear and the inner surface of the differential case side wall is caused by the meshing thrust force from the helical gear type pinion gears 2, 3 caused by an unbalanced relatively large driving resistance at the time of differential operation. When the differential is limited, the thrust force due to the meshing reaction force between the helical gear type pinion gears 2 and 3 and the left and right side gears 4 and 5 is added to the front limit force. Differential case 1A, the differential limiting force by the braking force of the elastic body 8 interposed made to have a predetermined fastening margin between the relative rotating parts between the side gears 4, 5 and the left and right between 1B occurs. Since the elastic body 8 interposed with these predetermined interferences can be configured to brake the relative rotating portion by surface contact, it is possible to always obtain a stable initial torque without generating abnormal noise. Can be.

In addition, a viscous fluid 9 is sealed between the relative rotating parts adjacent to the elastic body 8, and a large number of irregularities 10 capable of imparting shear resistance to the viscous fluid 9 are provided on at least one of the relative rotating parts. Due to the formation, apart from the thrust force due to the meshing reaction force between the helical gear-type side gears 4 and 5 and the pinion gears 2 and 3, the relative movement between the differential case 1 and the side gears 4 and 5 based on the differential operation. Also by rotation, a braking force, that is, a differential limiting force is generated between them, thereby effectively supplementing the initial torque due to the tightening of the elastic body 8 and exerting a higher differential limiting effect. Becomes possible. Further, the elastic body 8 can generate an initial torque by a predetermined braking force in the radial direction between the left and right side gears 4 and 5 by a tightening allowance, and can employ a seal member 8B having an X-shaped cross section to provide a differential gear. The limiting force can generate a predetermined braking force, that is, an initial torque, not only in the radial direction but also in the axial direction, and at the same time, can perform an effective sealing action of the viscous fluid. In addition, since the elastic body 8 is constituted by the spring member 8A and the seal member 8B, the predetermined interference can be maintained for a long period of time. Also, in the case where the pinion gear is not a helical pinion type, for example, the structure is the same as that of FIG. Even if no power is generated, a braking force of a certain magnitude, that is, an initial torque by the elastic body 8 interposed between the relative rotating parts, and a complementary differential limiting force due to the shear resistance of the viscous fluid 9 are generated. It is ensured that a high differential limiting effect is obtained.

The embodiments of the present invention have been described above.
The present invention is not limited to the differential device using the helical gear type pinion gear of the above-described embodiment, but can be applied to other types of differential limiting devices. In addition, in addition to the above-mentioned type of braking between the left and right differential cases and the inner and outer peripheries of the side gears as a relative rotating portion for obtaining a differential limiting force by braking, an elastic body or a viscous material is provided between the rear surface of each side gear and the inner wall of the differential case. It is also possible to arrange by configuring a fluid. Further, the shape and position of the concave portion for accommodating the elastic body in the relative rotation portion for obtaining the differential limiting force, the shapes of the spring member and the seal member constituting the elastic body, their related configurations and materials, and shearing of the viscous fluid The shape of the concavities and convexities for providing resistance can be appropriately adopted. Furthermore, the shape of the differential case, the shape of the pinion gear and the side gear, and the meshing-related configuration between them can be appropriately selected within the scope of the present invention.

[0013]

As described in detail above, the present invention provides
In a differential limiting device that obtains a differential limiting force by braking between relative rotating portions of a differential device, an initial torque is generated by providing an elastic body with a predetermined interference between the relative rotating portions. Therefore, the relative rotation portion can be braked by surface contact, and a stable initial torque, that is, a differential limiting force can be generated without generating abnormal noise. In addition, since the viscous fluid is sealed between the relative rotating parts adjacent to the elastic body, a braking force, that is, a differential limiting force is generated between the relative rotating parts based on the differential operation, thereby tightening the elastic body. The initial torque due to the margin can be effectively supplemented, and a higher differential limiting action can be exhibited. Moreover, by forming a large number of irregularities capable of imparting shear resistance to the viscous fluid on at least one side of the relative rotation portion, it is possible to more reliably obtain the differential limiting force.

The interference between the relative rotating portions formed by the elastic body can generate a predetermined initial torque between the relative rotating portions in the radial direction, the axial direction, or both directions. It can also perform an effective sealing action of a viscous fluid that can obtain a differential limiting force that complements the initial torque, can maintain the differential limiting action by the complementary viscous fluid of the initial torque for a long time, and as a whole, By generating a sufficient differential limiting force, a high differential limiting action can be exerted from low differential to high differential. As described above, according to the present invention, there is provided a differential limiting device employing an initial torque generating component that does not generate abnormal noise and can always obtain a stable differential limiting torque under a high differential limiting action. Is done.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a differential limiting device according to the present invention,
1 is an overall sectional view of a helical pinion type differential limiting device.

FIG. 2 shows an embodiment of the differential limiting device of the present invention, and is an enlarged view of a portion A in FIG. 1 and a sectional view thereof.

FIG. 3 is an overall sectional view of a conventional differential limiting device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 differential case 1C case cylinder 1D case cylinder 1E recess 2 helical gear pinion gear (double teeth) 3 helical gear pinion gear (single tooth) 4 left side gear 4C small boss 5 right side gear 5C small boss 7 thrust Washer 8 elastic body 8A spring member 8B seal member 9 viscous fluid 10 unevenness

Claims (4)

[Claims] 1. A differential device for transmitting a rotational driving force of a differential case to a left and right side gear disposed on a rotation shaft of the differential case through a pinion gear rotatably supported or accommodated in the differential case. In a differential limiting device that obtains a differential limiting force by braking between rotating parts, an initial torque is generated by interposing an elastic body with a predetermined interference between the relative rotating parts. Characteristic differential limiting device. 2. The differential limiting device according to claim 1, wherein a viscous fluid is sealed between the relatively rotating parts adjacent to the elastic body. 3. The differential limiting device according to claim 1, wherein the elastic body that gives the relative rotation portion a predetermined interference is constituted by a spring member and a seal member. 4. The viscous fluid according to claim 1, wherein a plurality of irregularities capable of imparting a shearing resistance to the viscous fluid are formed in at least one of the relative rotating portions filled with the viscous fluid. 4. The differential limiting device according to claim 1.