JP2569143Y2 - Differential limiter - Google Patents

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 used for a vehicle or the like.

[0002]

2. Description of the Related Art Conventionally, as this type of differential limiting device,
For example, there is one shown in FIGS. 7 and 8 described in Japanese Patent Application Laid-Open No. 3-37455.

In this differential limiting device 1, a first driven shaft gear 5 and a second driven shaft gear 7 are coaxially supported by an intermediate sleeve 9 in a housing 3, and a first driven shaft gear 5 is provided. The shaft gear 5 is engaged with a first group of four balancing gears 11 distributed asymmetrically around the circumference, and the balancing gears 11 are engaged with the second group of four balancing gears 13 in a pair, respectively. The balance gears 13 of the second group are engaged with the second driven shaft gear 7.

A carrier 15 is held in the housing 3 so as to be movable in the radial direction, and all the balancing gears 11 and 13 and the first and second driven shaft gears 57 are slidable in the carrier 15. Is housed in The radial movement of the balancing gears 11 and 13 pushes the carrier 15 on the opposite side to the driven shaft gears 5 and 7.

In such a differential gear device 1, when there is a difference in the number of rotations between the driven shaft gears 5 and 7 to which torque is applied, the fixing action is performed by the reaction force of the balance gears 11 and 13. Is caused by a corresponding additional frictional force between the driven shaft gears 5 and 7 and the carrier 15 caused by sliding in the radial direction.

[0006]

However, such a conventional differential gear device has a problem that the number of parts is increased, the structure is complicated, and the weight is heavy.

[0007] Therefore, the present invention aims to provide a differential limiting device capable of improving functions with a simple structure.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a differential case which is connected to a drive side and rotates, a pinion shaft which rotates integrally with the differential case, and a pinion shaft which is rotatable. A supporting pinion gear; and a pair of side gears meshing with the pinion gear. The boss portion of the pinion gear is rotatably supported by a support hole of the differential case, and a lightening portion is provided in the support hole. The contact surface is formed with a predetermined angle before and after the torque transmission direction.

[0009]

When the differential rotation between the side gears occurs, the differential limiting force can be obtained by the stable frictional resistance generated on the contact surface between the boss of the pinion gear and the support hole of the differential case.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an upper half of a sectional view of a differential limiting device according to an embodiment of the present invention.

The differential case 21 is rotatably supported by a differential carrier (not shown), and a ring gear (not shown) connected to a drive shaft (not shown), which is a driving side, is fixed to the differential case 21 so that the ring gear and the differential case 21 are fixed. 2
1 and rotates together.

A pinion shaft 23 is provided substantially at the center of the differential case 21. A pair of pinion gears 25 are rotatably mounted on the pinion shaft 23.
The pinion gear 25 has a boss 27, and the boss 27
Are rotatably fitted in the support holes 29 of the differential case 21. A plurality of (four in FIG. 2) lightening portions 31 are provided in the support holes 29 of the differential case 21 as shown in FIG.
A predetermined angle γ is given to the contact surface 33 between the pinion gear 25 and the support hole 29 with respect to the front and rear in the torque transmission direction.

The pinion gear 25 has a differential case 2
A pair of side gears 35 arranged coaxially with 1 mesh from left and right. An axle (not shown) is connected to the side gear 35 by spline fitting.

The side gear 33 includes a cone clutch 3.
7 are provided. On the other hand, the inner peripheral surface of the differential case 21 has a cone shape, and the inner peripheral surface 21a engages with the outer peripheral surface 37a of the cone clutch 37.

Next, the operation of the embodiment will be described.

When the differential case 21 is rotated by rotation of a ring gear (not shown) connected to the driving side, the rotation is transmitted to a side gear 35 via a pinion shaft 23 and a pinion gear 25, and left and right sides (not shown) connected to the side gear 35. Rotate the axle. At this time, if a driving resistance difference occurs between the left and right axles, the driving force is differentially distributed between the left and right axles due to the rotation of the pinion gear 25.

On the other hand, when a difference in driving resistance between the left and right axles occurs, that is, when the side gears 35 rotate differentially, friction occurs on the contact surface 33 between the boss portion 27 of the pinion gear 25 and the support hole 29 of the differential case 21. resistance force f _p occurs.
The frictional resistance force f _p is the angle of the contact surface 33 of the boss portion 27 and the supporting hole 29 gamma, when the friction coefficient between them and mu _1,

(Equation 1) Given by with γ amplifies the frictional resistance force f _p, it acts to keep the contact angle of the pinion gear 25 and the differential case 21 constant to stabilize.

Further, the side gear 35 and the pinion gear 2
The cone clutch 37 is fastened by the thrust force meshing with the cone clutch 37. The fastening force f _G is defined as r _{G as} the inner diameter of the meshing pitch between the pinion gear 25 and the side gear 35, r _{C as} the effective diameter of the cone clutch 37, β as the inclination angle of the cone clutch 37, and α as the pressure angle of the pinion gear 25 and the side gear 35 as α. , The maximum root diameter of the pinion gear 25 (the diameter of the boss portion 27) is r _p , and the friction coefficient of the cone clutch 37 is μ _2.

(Equation 2) Given by

Furthermore, since it is given a differential limiting force f by the fastening force f _G of the frictional resistance force f _p and the cone clutch 37 of the boss portion 27 and the support hole 29 of the pinion gear 25,
This differential limiting force f is

(Equation 3) Becomes

The differential rotation between the axles is limited by the differential limiting force f, and torque is distributed to both wheels as needed.

According to this embodiment, since the differential limiting effect can be obtained only by changing the shape of a part of the components constituting the ordinary differential gear device, the structure is extremely simple and the reliability is high. Can be improved.

FIGS. 3 and 4 show another embodiment of the present invention. 1 and 2 are denoted by the same reference numerals, and redundant description will be omitted.

In this embodiment, a disc spring 39 for urging the pinion gear 25 in the axial direction of the pinion shaft 23 is provided between the boss 27 of the pinion gear 25 and the support hole 29 of the differential case 21. The disc spring 39 is prevented from coming off by a stop ring 41 provided on the pinion shaft 23.

According to this embodiment, the pinion gear 25 and the side gear 35 are pre-loaded by the spring force of the disc spring 39.
5, a predetermined initial torque is applied to the cone clutch 37, and as shown in FIG. 5, when a driving resistance difference occurs between the left and right axles, braking is applied to the side gear 35 to limit the differential.

Therefore, the vehicle is stabilized by running on an icy road or severe cornering.

FIG. 6 shows a modification of FIG. 4. In this embodiment, a disc spring 39 is provided in the opposite direction.

Accordingly, the same effects as in the above embodiment can be obtained.

[0029]

As is clear from the above description, according to the present invention, a highly reliable differential limiting device with an extremely simple structure can be obtained.

[Brief description of the drawings]

FIG. 1 shows an upper half of a sectional view of a differential limiting device according to an embodiment.

FIG. 2 is a view showing an arrow II in FIG. 1;

FIG. 3 shows an upper half of a sectional view of another embodiment.

FIG. 4 is a view showing an arrow IV in FIG. 3;

FIG. 5 is an operation explanatory view.

FIG. 6 shows an upper half of a sectional view of a modification of FIG. 3;

FIG. 7 is a longitudinal sectional view showing a conventional example.

FIG. 8 is a sectional view taken along line IIX-IIX of FIG. 7;

[Explanation of symbols]

 21 Diff Case 23 Pinion Shaft 25 Pinion Gear 27 Boss 29 Support Hole 35 Side Gear 37 Cone Clutch

Claims (1)

(57) [Scope of request for utility model registration] A differential case that is connected to and rotates with the driving side, a pinion shaft that rotates integrally with the differential case, a pinion gear rotatably supported by the pinion shaft, and a pair of side gears that mesh with the pinion gear. A boss portion of the pinion gear is rotatably supported in a support hole of the differential case, and a lightening portion is provided in the support hole to provide a predetermined angle between a contact surface between the boss portion and the support hole in the torque transmission direction. A differential limiting device characterized by being formed as follows.