JPH0313644Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Technical field of invention) The present invention relates to a differential device for a vehicle.

(Prior art) As a differential device for a vehicle, a plurality of sets of two worm wheels are arranged in a differential case, a worm is attached to each of a pair of axles, and a worm wheel of each set is installed. Some wheels are constructed by engaging one of the worm wheels of a pair of axles, and the other of each set of worm wheels engages the worm of the other of a pair of axles (POPULAR).
SCIENCE p. 58~, February 1984). In addition to having the original differential function, this differential device also has the function of changing the distribution ratio of driving force and transmitting it to the wheels, so that both functions can be performed without sacrificing one during traction and turning.

(Problem to be solved by the invention) By the way, in the above-mentioned differential device, the two worm wheels mesh in a one-to-one relationship via spur gears provided at both ends of each worm wheel, and the structure is Since this is very complicated, it is difficult to increase productivity and costs are high, so a new differential device was proposed (Japanese Patent Application No. 59-260692; Japanese Patent Application Laid-open No. 61-140654). .

This differential device includes a differential case,
a worm wheel rotatably supported by the differential case; a pair of worms that engage with the worm wheel and are rotatably arranged at symmetrical positions with respect to the center of the worm wheel; A pair of first side gears arranged on both sides of the worm wheel on the axis of the pair of worms, one of which is connected to one of the pair of worms, and the other is connected to the other of the pair of worms. a first side gear, a second side gear that meshes with each of the first side gears, and an axle connected to the second side gear.

The above-mentioned two differential devices, that is, the differential device in which the differential section consisting of the worm wheel and the worm is placed inside the differential case, can improve the differential characteristics without changing the torsion angle of the worm. , it is preferable that it can be easily adjusted.

The present invention provides a differential device that has a differential section composed of a worm wheel and a worm, and whose differential characteristics can be easily adjusted.

(Means for Solving the Problems) The present invention is a differential device in which a differential portion constituted by a worm wheel and a worm is disposed in a differential case, and in which and a friction torque generating means provided between the worm wheel or worm and the differential case.

(Example) As shown in FIG. 1, the differential device 10 includes a differential case 12 and a worm wheel 1.
A differential section constituted by the worm wheel 14 and the worm 16 is disposed within the differential case 12.

Differential case 12 is link gear 1
8 and both are rotatably disposed within the differential carrier. A pinion shaft is rotatably supported by the differential carrier, and a pinion of the pinion shaft meshes with the ring gear 18 to rotate the ring gear 16 and the differential case 12.
The configuration is the same as that of a conventional differential device, so illustration is omitted.

The worm wheel 14 is disposed approximately at the center within the differential case 12 and is rotatably held by a shaft 20. A worm wheel 14 is spline-fitted to the shaft 20, and as shown in FIG. 2, the shaft 20 is rotatably supported by a pair of supports 22 disposed within the differential case 12 via bearings. As a result, the worm wheel 14 cannot rotate relative to the shaft 20 and is movable in the axial direction.

In the illustrated example, two worms 16 are provided,
Each meshes with a worm wheel 14. The two worms 16 have the same size, that is, the same design values, and are arranged symmetrically with respect to the axis of the shaft 20 that supports the worm wheel 14. The worm wheel 14 and the worm 16 may both be cylindrical or hourglass-shaped.

The pair of worms 16 are rotatably held by shafts 24 and 26, respectively. As shown in FIG. 3, the shaft 24 has a spline 25, into which the worm 16 is fitted. Thereby, the worm 16 cannot rotate with respect to the shaft 24 and can move in the axial direction. The shaft 24 is
The differential case 12 passes through one of a pair of support parts 28 (one support part is shown in FIG. 3) disposed inside the differential case 12.
It extends toward one wall surface 29a. axis 24
is rotatably supported via a bearing 30.

The shaft 26 has the same configuration as the shaft 24, and supports the worm 16 located below in FIG. 1 so as to be non-rotatable but movable in the axial direction. The shaft 26 is arranged parallel to the shaft 24, extends toward the other wall surface 29b of the differential case 12, and is rotatable.

A first side gear 32 is fixed to one shaft 24, and a first side gear 34 is fixed to the other shaft 26, respectively. Side gear 32 and side gear 3
4 is the same size, and as shown in Figure 1,
In a plan view of the differential device 10, they are arranged on both sides of the worm wheel 14. In the illustrated example, the side gear 32 is arranged on the upper right side of the worm wheel, and the side gear 34 is arranged on the lower left side of the worm wheel. Both side gears 32 and 34 are connected to the shaft 2 that supports the worm wheel 14.
Preferably, the position is symmetrical with respect to the zero axis. The side gears 32 and 34 are formed by spur gears, helical gears, or bevel gears.

A second side gear 36 that meshes with the first side gear 32 and a second side gear 38 that meshes with the first side gear 34 are provided. The side gears 36 and 38 have the same size and are formed by spur gears, helical gears or bevel gears depending on the first side gear.

An axle 40 is coupled to the side gear 36 and an axle 42 is coupled to the side gear 38, and each axle is rotatable with respect to the differential case 12. The axle 40 extends to the right, perpendicular to the axis 20 of the worm wheel 14, and the axle 42 extends to the left, perpendicular to the axis 20 of the worm wheel 14. A wheel (not shown) is connected to each axle.

A friction torque generating means 50 is provided between the worm wheel 14 and the differential case 12 in the axial direction of the worm wheel 14.
A friction torque generating means 50 having the same configuration is provided between the worm 16 and the differential case 12 in the axial direction of each worm 16.

The friction torque generating means 50 shown in FIG.
It is provided between the worm 16 located above in the figure and the support portion 28 on the left side. In the illustrated example, the friction torque generating means 50 includes a clutch cage 52, three inner clutch plates 54, two outer clutch plates 56, and two thrust washers 58.

The clutch cage 52 has an annular clutch portion 60.
and four leg portions 61 that are arranged at equal intervals in the circumferential direction of the clutch portion 60 and extend toward the support portion 28, and each leg portion 61 is formed in a hole provided in the support portion 28. It is movably inserted into 29.

The inner clutch plate 54 is fitted into the spline 25 of the shaft 24, and is not rotatable with respect to the shaft 24 but is movable in the axial direction.

The outer clutch plate 56 is an annular plate, and as shown in FIG. 4, has a notch 57 on its outer periphery that can receive the leg 61 of the clutch cage 52. The outer clutch plate 56 is loosely inserted into the shaft 24 and is movable in the axial direction, but is prevented from rotating by the legs 61.

The thrust washer 58 consists of an annular plate. This thrust washer 58 is loosely inserted into the shaft 24 and disposed between the inner clutch plate 54 and the outer clutch plate 56, and the number thereof can be increased or decreased as appropriate to adjust the clearance.

When the differential gear 10 is used, when a thrust force is applied between the worm 16 and the support part 28, the worm 16
moves toward the support part 28, and the clutch part 60,
Pressing the inner clutch plate 54, thrust washer 58, and outer clutch plate 56 with the support part 28,
Friction torque proportional to the number of these sheets is generated.
Since friction torque acts as a resistance to the rotation of the worm 16, the differential characteristics can be adjusted by adjusting the friction torque by adjusting the number of inner clutch plates 54, thrust washers 58, and outer clutch plates 56.

In the above example, the friction torque generating means 50 is provided on both sides of the worm wheel 14 and on both sides of each worm 16. Alternatively, a friction torque generating means 50 can be provided in association with the worm wheel 14 or the worm 16.

In the differential gear 10 shown in FIG. 5, the friction torque generating means 50 is arranged only on one side of the pair of worms 16. In this case, the friction torque generating means 5
0, one acts when the vehicle moves forward, and the other acts when the vehicle moves backward.

The differential device 60 shown in FIG. 6 includes a differential case 62, a worm wheel 64, and a worm 66.
A differential section is arranged.

The worm wheels 64 are of the same size 2
The two worm wheels 64 of each set are restrained by spur gears 68 arranged at both ends. A plurality of sets of worm wheels configured in this manner are supported within the differential case 62 so as to be side gearable.

Two worms 66 of the same size are provided, and are spline-fitted to axles 70 and 72 which are rotatably arranged in the center of the differential case 62, so that they cannot rotate relative to the axles and are aligned with the axis. It is now possible to move in any direction.
One worm 66 meshes with one of the plural sets of worm wheels 64, and the other worm 66 meshes with the other worm wheel 64. Warm 6
A friction torque generating means 50 is disposed between the worm 66 and the differential case 62 in the axial direction of the worm 66 .

In the differential device 60 shown in FIG. 7, each worm wheel 64 and each spur gear 68 are spline-fitted to a shaft 74 rotatably supported by the differential case 62, and rotate relative to the shaft 74. and is movable in the axial direction. A friction torque generating means 50 is arranged between the spur gear 68 and the differential case 62 in the axial direction of the worm wheel 64.

(Effects of the Embodiment) Differential Function: Assume a case where the left axle 42 rotates by ΔN more than the differential case 12 and the right axle 40 rotates by ΔN less than the differential case 12.

In FIG. 1, as the left axle 42 rotates by ΔN in the A direction, the left worm 16 (lower worm in the figure) is moved in the B direction via the left second and first side gears 38, 34. Rotate. This causes the worm wheel 14 to rotate in the C direction.

Here, when the right axle 40 rotates by ΔN less than the differential case 12, it means that the right axle 40 rotates by ΔN in the direction D, which is opposite to the left axle 42.
The right worm 16 (the upper worm in the figure) is rotated in the E direction via the right second and first side gears 36 and 32 by the amount of ΔN rotation of 0 in the D direction.

The rotation of the left worm 16 in the B direction is a clockwise rotation of the left worm 16 when the left worm 16 is viewed from the side gear 34. On the other hand, the rotation of the right worm 16 in the E direction is caused by the side gear 32.
When looking at the right worm 16 from above, this is a clockwise rotation of the right worm 16. This means that the worm wheel 14 rotates in the C direction as the right worm 16 rotates in the E direction. That is, if the left worm 16 and the right worm 16 rotate the worm wheel 14 in the same direction, as is clear from FIG.
2 and 40 will be differentially operated.

Distribution of driving force: Assume that the load on the left axle 42 is zero and the vehicle is about to spin.

In this case, as if spinning, left axle 4
In an attempt to increase the rotation level of the left axle 42, the second and first side gears 38,3
4. Attempt to rotate the engaged gears such as the left worm 16 and worm wheel 14. However, at this time, the fact that the worm wheel 14 rotates the right worm 16 means that the right worm 16
This is not possible unless the rotation is reversed. As a result, the axle 42, the second and first side gears 38, 34
cannot increase the level of rotation, so it does not spin and all drive power can be transferred to the right axle 40.

(Effect of idea) According to the present invention, the following effects can be obtained.

Since the friction torque generating means is arranged between the worm wheel or worm and the differential case in the axial direction of the worm wheel or worm, the axial force acting on the worm wheel or worm when using the differential device causes A friction torque generating means can be activated. As a result, the differential characteristics, particularly the bias ratio, can be adjusted without changing the twist angle of the worm.

Both differential function and drive power distribution function can be achieved without sacrificing one during towing or turning. It also prevents spin and ensures steering stability when turning, driving on frozen roads, etc.

[Brief explanation of the drawing]

FIG. 1 is a sectional view schematically showing the main parts of the differential gear, FIG. 2 is a sectional view taken along line 2-2 in FIG. 1, and FIG. 3 is a sectional view of the friction torque generating means.
FIG. 4 is a sectional view taken along the line 4--4 in FIG. 3, and FIGS. 5 to 7 are sectional views schematically showing essential parts of another differential gear. 10, 60: differential gear, 12, 62: differential case, 14, 64: worm wheel, 16, 66: worm, 32, 34: first side gear, 36, 38: second side gear, 4
0, 42: Axle, 50: Friction torque generating means.

Claims (1)

[Scope of utility model registration request] A differential device in which a differential section constituted by a worm wheel and a worm is disposed in a differential case, wherein the worm wheel or the worm and the differential case are arranged in an axial direction of the worm wheel or the worm. A differential device including a friction torque generating means provided between.