JPH0447469Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention relates to improvement of a differential device.

(B) Prior Art A differential device that transmits the rotational force of a differential case that rotates in conjunction with a drive shaft to a wheel shaft via a pinion gear and a side gear is well known. The pinion gear of this device plays the role of transmitting the above-mentioned power while allowing differential movement between the left and right wheel axles, thereby allowing the vehicle to travel smoothly around curves.

However, with such a differential device, if one wheel falls into muddy ground, the rotational force is mainly transmitted to the wheel axle with a smaller load, that is, the wheel axle that has fallen down. However, due to the high speed slip rotation of the fallen wheel, it is inconvenient that it becomes difficult to get the wheel out of the muddy ground.

In order to eliminate such inconvenience, various differential limiting mechanisms have been proposed that limit the differential movement of pinion gears when the relative rotational speed of the left and right wheel axles exceeds a predetermined value. The differential limiting mechanism includes, for example, an inner rotor fixed to the wheel axle and an eccentric outer rotor that meshes with the inner rotor, and has a pumping means that performs a pumping action by relative rotation between the differential case and the wheel axle. There are some (see Utility Model Publication No. 46-35772).

Then, due to the relative rotation between the differential case and the wheel axle, the pump means sucks up the lubricating oil scraped up by the rotation of the differential case and performs a pumping action, and the drive reaction force of this pump means acts as a regulator of the relative rotation. do. Therefore, when the relative rotation speed is above a predetermined value, it is possible to limit this relative rotation.

However, since the lubricating oil used for the pumping action is scraped up by the rotation of the differential case, it is not sufficiently distributed to the pumping means, which may damage the differential limiting mechanism. In addition, the lubricating oil that is scooped up by the differential case is only for lubrication, and its properties are regulated, so the differential limiting function cannot be fully utilized, and there is a risk that the degree of freedom in design will be restricted. It was hot.

(c) Purpose of the invention This invention was created in view of the above problems.
The purpose is to provide a differential device that can further improve the differential limiting function and increase the degree of freedom in design.

(d) Structure of the invention In order to achieve the above object, the invention includes a differential case, a pair of side gears that rotate together with a pair of shafts that are rotatable with respect to the differential case, a pinion shaft that receives rotational input from the differential case side, and a pinion. In the differential device, the differential case includes a pinion gear that is rotatably provided on the shaft and meshes with the pair of side gears, and a differential limiting coupling that is provided in the differential case, and the differential case has a side wall portion in the direction of the rotation axis of the differential case. The coupling ring is provided between the divided parts and has a circular shape eccentric to the rotational axis of the differential case. an annular coupling chamber; an annular outer rotor provided in the coupling chamber and slidably supported in the circumferential direction in the coupling chamber and having internal teeth; and an external tooth meshing with the internal teeth of the outer rotor; The coupling chamber has an inner rotor fixed to the shaft thereof, and a fluid sealed inside the coupling chamber.

(E) Example An example of the present invention will be described below based on screens.

As shown in FIG. 1, the embodiment device of the present invention has the following features:
It has a differential case 1 that rotates in conjunction with a drive shaft (not shown). This differential case 1
consists of a left end case 1a, a side case 1b, and a right end case 1c.The left end case 1a and the side case 1b are fixed with fastening screws 3, and the side case 1b and the right end case 1c are connected with bolts 5. It is fixed by. Therefore, the differential case 1 has a divided part on the side wall in the direction of the rotation axis, and has a side case 1b as a part that houses the side gears 11, 13, etc., and a left end case 1a as a part that covers the outer end surface. is forming. and,
A ring gear (not shown) is formed on the peripheral surface of the side end of the left end case 1a, and this ring gear meshes with a drive pinion (not shown).

A left wheel shaft 7 is rotatably supported on the left end case 1a, and a right wheel shaft 9 is rotatably supported on the right end case 1c as a pair of shafts rotatable with respect to the differential case 1. , 9 have side gears 11, 13 fixed to their ends. On the other hand, a pinion shaft 15 is fixed to the side case 1b in a direction orthogonal to the axes of the wheel shafts 7 and 9, and a pinion gear 17 is rotatably fitted into the pinion shaft 15. This pinion gear 17 meshes with both side gears 11 and 13.

Counterbore step surfaces are formed on the opposing surfaces of the left end case 1a and the side case 1b, and the space surrounded by the left wheel axle 7 and the step surfaces of both cases 1a and 1b is the differential case. The coupling chamber 19 has an annular shape and is eccentric with respect to the center line of the rotation axis. A rotor 21 is housed within this coupling chamber 19, and a coupling for limiting differential movement is configured. This rotor 2
1 consists of an inner rotor 23 and an outer rotor 25. The inner rotor 23 is fitted and fixed to the left wheel shaft 7, and external teeth 23a are provided around the outer peripheral surface of the inner rotor 23. On the other hand, the outer rotor 25 is formed in an annular shape, and has the outer teeth 2 on its inner peripheral surface.
Internal teeth 25a having one more tooth than 3a are provided around the periphery. A portion of the inner teeth 25a is engaged with a portion of the outer teeth 23a of the inner rotor 23 when the outer rotor 25 is fitted into the inner rotor 23. The inner rotor 23 is supported concentrically with respect to the differential case 1, and the outer rotor 25 is eccentric by a predetermined amount e, and its outer peripheral surface is in sliding contact with the differential case 1.

Seal members 27 each made of an O-ring are interposed between the shaft of the inner rotor 23 and the bearing of the differential case 1 that supports this shaft, and on the pressure contact surface between the left end case 1a and the side case 1b. The coupling chamber 19 is kept in a sealed state. And this coupling room 19
Silicone oil 29 is sealed inside as a fluid.

A thrust block 31 is slidably and rotatably provided at the end of the left wheel shaft 7 by being fitted into the shaft hole of the side gear 11, and this thrust block 31 is connected to the pinion shaft 15 via a spring pin 33. is mated to.

The embodiment of the present invention has the above configuration, and the operation of the embodiment will be explained below.

When the vehicle is running, the rotation of the drive pinion is transmitted to the differential case 1 through engagement with the ring gear, and the rotation of the differential case 1 is further transmitted to the side gears 11 and 13 via the pinion gear 17, and due to the rotation of the left and right wheel axles 7 and 9. , the vehicle is traveling straight ahead. When the vehicle travels around a curve, the relative rotation of the left and right wheel axles 7, 9 is effectively absorbed by the differential rotation of the pinion gear 17, resulting in smooth travel.

Next, when a wheel on one side, for example, the left vehicle, falls into muddy ground while the vehicle is running, the load on this left wheel decreases, so the rotational force from the differential case 1 is mainly applied to the left wheel axle 7. The left wheel starts rotating at high speed. At this time, the left wheel axle 7
The inner rotor 23 fixed to the inner rotor 23 and the outer rotor 25 meshing with the inner rotor 23 also rotate at high speed, and the rotor 21 and the differential case 1
A high rotational speed difference occurs between the two, and the rotor 21 rotates at a high speed within the coupling chamber 19 in response to this rotational speed difference. In this case, since the rotational axes of the inner rotor 23 and the outer rotor 25 are eccentric, the silicone oil 29 between the two rotors 23 and 25 is
are sent out one after another in the rotational direction, and return to the original position after each rotation. This kind of resistance action causes the rotor 21
However, as the rotation of the rotor 21 becomes faster, its rotational resistance increases, and this resistance limits the rotation of the side gear 11, and the rotational force of the differential case 1 is also applied to the right wheel axle. Conveyed. As a result, the vehicle can easily escape from the muddy area.

In this embodiment, the coupling chamber 19 is made airtight, and the silicone oil 29 is filled in this airtight coupling chamber 19, so that it is completely independent of the properties and deterioration of the lubricating oil, and is The differential function can be improved in any condition, regardless of whether the wheels are tilted or not, and the wheels can easily escape from muddy ground. Further, since the coupling chamber 19 is made airtight, the silicone oil 29 in the coupling chamber 19 is not mixed with lubricating oil, and therefore oils with various properties different from lubricating oil can be used as the fluid. This makes it possible to increase the degree of freedom in device design.

(f) Effects of the invention Since the invention is constructed as described above,
The differential limiting function can be improved regardless of the properties and deterioration of the lubricating oil, and a sufficient amount of fluid for resistance can be secured, so the differential limiting function can be significantly improved. Moreover, the properties of the fluid can be freely set separately from those of the lubricating oil, increasing the degree of freedom in design. Further, since the coupling ring is provided in the divided portion of the differential case, the coupling ring can be easily assembled by dividing the differential case. Replacing the fluid sealed in the coupling chamber, disassembling and repairing the coupling,
It is extremely easy to assemble, and the split parts can be joined together with the ring gear attachment.

Furthermore, while the differential case has a coupling ring for limiting differential movement, the split part of the side wall of the differential case consists of a part that houses the side gear etc. and a part that covers the outer end surface of the differential case. It is possible to assemble side gears etc. into a unit. Then, the coupling ring can be assembled and completed. Therefore,
Separate assembly lines can be set up for assembling side gears, pinion gears, etc. into the differential case to form a unit as a differential mechanism, and an assembly line for subsequently assembling the coupling.
The ease of assembly is significantly improved.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the configuration of the device of the present invention, Figure 2
The figure is a sectional view showing the internal structure of the coupling chamber of the device of the present invention. 1...Differential case, 7...Left wheel axle (axle), 9
...Right wheel axle (shaft), 11, 13...Side gear,
15... Pinion shaft, 17... Pinion gear, 19... Coupling chamber, 21... Rotor,
23...Inner rotor, 23a...External tooth, 25
...Outer rotor, 25a...Inner tooth, 29...
Silicone oil (fluid), e... Eccentricity.

Claims (1)

[Scope of utility model registration request] a differential case, a pair of side gears that rotate together with a pair of shafts that are rotatable with respect to the differential case, a pinion shaft that receives rotational input from the differential case side, a pinion gear that is rotatably provided on the pinion shaft and meshes with the pair of side gears, and the differential case. In the differential device, the differential case has a divided portion on a side wall portion in the direction of the rotational axis, and has a portion housing the side gear etc. and an outer end surface thereof. the coupling chamber has an annular coupling chamber provided between the divided portions and eccentric to the rotational axis of the differential case; an annular outer rotor that is slidably supported and has internal teeth; an inner rotor that is fixed to the one shaft and has external teeth that mesh with the internal teeth of the outer rotor; and an inner rotor that is enclosed within the coupling chamber. A differential device comprising a fluid.