RU2347123C2 - Wheeled vehicle differential gear - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to vehicles, in particular to self-locking differential gears and can be used in both transfer box and wheel gears. The propose vehicle differential gear comprises the housing, final drive, differential gear housing with half shaft gears and cams fitted therein. The said half shaft gears are in mesh with differential pinions. The said cams are helically-cammed with half shaft gears to get in contact with the push rods furnished with rollers. The thrust bearing is fixed on the reduction gear housing, the bearing movable race features a cam-like surface to interact with push rod rollers. The bearing cage inner surface features helical grooves or a diametral bore with through holes. The coupling holds the cage down to the thrust bearing fixed race with the help of plate spring.

EFFECT: mechanical control over differential gear capable of distinguishing between slipping and normal operating conditions.

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Description

The invention relates to vehicles, in particular to self-locking differentials. It can be used both in the transfer case and in the wheel gearboxes, providing the car with all-wheel drive in constant operation.

A self-locking differential is known that contains a housing and semi-axial gears mounted inside it, connected by gearing to satellites mounted on spikes of a cross, friction clutches, the friction surfaces of which are connected to one of the satellites and the other to the spike of the cross (analogue A. Lefratov. Differentials of cars and tractors. M.: "Engineering", 1972, p. 83-84, Fig. 44).

The disadvantage of this differential is the design complexity caused by the presence of support washers and their connection with the satellite and spike spikes, which increases the differential metal consumption.

A known mechanism for locking the differential of a vehicle containing a cam clutch made of two parts, one of which is movable in the axial direction and kinematically connected with the controls, and the other fixed is equipped with a coaxially mounted ring with end cams having profiled tops (analogue A.C. USSR No. 659423, B60K 17/20).

The disadvantages of the mechanism are increased dynamic loads when the differential is turned on, the complexity of manufacturing a split ring and the assembly of the locking mechanism.

A device is known for locking the differential of a wheeled vehicle, which contains an axle axially spring-loaded axle connected with gear teeth and connecting teeth and driven by the pressure of the working agent of the power cylinder (analogue, AS No. 1047741, B60K 17/20).

A disadvantage of the known device is the design complexity of the differential lock device, which reduces the reliability of its operation.

A self-locking conical differential is known, having a locking device in the form of an insert with teeth on two opposite sides, mounted on the axis of the satellites and interacting with the teeth of opposing gears, when slipping, blocking their rotation (prototype - patent RU 2090793 C1, V. Kuzevanov). The disadvantage of this solution is the inability to distinguish slippage from the turning of the vehicle, which poses a danger to traffic and the latter is inherent in all self-locking devices to one degree or another.

The objective of the invention is to create a mechanical differential control system that can distinguish slippage from the normal mode of movement of the vehicle and prevent it with great efficiency.

The task is achieved in that in the known differential, comprising a housing and semi-axial gears mounted inside it, connected by gearing to the satellites, cams are provided having a support, which actuate the pushers with rollers, also located in the differential housing. The second part of the mechanism is mounted on the gear housing and is a thrust bearing. Moreover, the movable cage of this bearing is made with a cam surface, with which the pusher rollers interact. The separator on the inside has surfaces with spiral grooves or a diametrical channel with through holes (depending on the lubricant used). A clutch connected by splines to the differential housing and resting on a Belleville spring with a design force presses the separator against a stationary clip.

Comparison of the claimed technical solution with the prior art in scientific, technical and patent documentation at the priority date in the main and related sections shows that the set of essential features of the claimed solution was not known. Therefore, it meets the condition of patentability “novelty”.

Analysis of known technical solutions in the art showed that the proposed device has features that are not in the known technical solutions, and using them in the claimed combination of features makes it possible to obtain a new economic effect, therefore, the proposed solution has an inventive step compared to the existing level of technology .

The proposed technical solution is industrially applicable, because can be manufactured industrially, efficiently, feasibly and reproducibly, therefore, meets the patentability condition “industrial applicability”.

Figure 1 is a kinematic diagram of a wheel gear with the proposed differential;

Figure 2 - General view of the gear assembly;

Figure 3 is a General view of the proposed differential;

Figure 4 is a General view, section;

Figure 5 is a General view without bearings (section at an angle of 90 °);

Figure 6 is a General view without bearings, section;

7 is a section by a plane in the center of the satellites perpendicular to the main axis;

On Fig - block gears and cams in engagement;

Figure 9 is an explosion diagram of the differential.

The differential includes a box 1, semi-axial gears 2, a support 3, satellites 4, a clutch 5, a cage 6, a thrust bearing race 7, a thrust bearing race with cam surface 8, pushers 9, rollers 10, a disk spring 11, double-engagement cams 12, adjusting washers 13, thrust ball bearings 14, unilateral gear cams 15, mounting bolts 16, pins 17, the main pair of gears 18, gear housing 19.

For the kinematic scheme - wheels 20, road surface 21.

The differential works as follows.

During the rectilinear movement of the car, the main pair of gears 18 rotates the box 1. The gears of the half shafts 2, the satellites 4, the cams 12, 15, the pushers 9, the rollers 10, the thrust bearing race with the cam surface 8 are stationary relative to the gearbox 1. Separator 6 with balls 14 rotates with an arithmetic average speed of rotation with respect to the housing 19 and to the differential box 1. The coupling 5, with the help of a disk spring 11, presses the cage 6 against the cage of the thrust bearing 7. By means of spiral channels on the surface In the separator 6, a hypoid lubricant film is formed between the mating surfaces with increasing speed of rotation of the box 1, sliding friction is reduced.

When making a turn or hitting an obstacle, as well as during the loss of traction on the road surface of one gear wheel of the axle shaft 2, the satellites 4 rotate in different directions. Cams 12, 15 make reciprocating movements along the radius, driving pushers 9 with rollers 10, which make the cage with cam surface 8 rotate in different directions, depending on the direction of rotation made by the car. The separator 6, compressed by the cage 7 and the sleeve 5, are affected by the equivalent and opposite pole friction and pressure forces. In parallel, the force transmitted by the cage 8 through the balls 14 with a different sign is connected, depending on the direction of the vehicle, forcing the separator 6 to equalize the revolutions with the differential box 1 or with the gear housing 19. At friction surfaces that stop between themselves, the lubricant is squeezed out due to the pressure springs 11. According to the design, the cage with cam surface 8 does not have sufficient force to violate the speed limits of the separator 6 (border 1 is the gear housing, always 0, border 2 is the speed of the box ifferentsiala) due to a small helix angle of the cam surface. Consequently, the entire differential mechanism will be limited in its actions, but not blocked in a predetermined range, allowing the vehicle to make a sufficiently small turning radius without difficulty.

The claimed solution in comparison with the prototype allows you to fully automate the differential operation of a wheeled vehicle and increase the reliability of the device due to the presence of mechanical logic obtained by the proposed design solution and able to distinguish between turning the car from the loss of adhesion of the wheel to the road surface (slipping). The mechanism does not interfere with making a turn or hitting an obstacle, but also protects the car from slipping with great efficiency.

Claims (1)

A differential of a wheeled vehicle, comprising a gear housing, a final drive, a differential box with semi-axial gears installed therein, connected by gearing to the satellites, characterized in that cams are provided that are in helical gearing with the semi-axial gears with the possibility of contact with pushers having rollers also located in the differential box; a thrust bearing is fixed on the gear case, the movable cage of which is made with a cam surface, with which the pusher rollers interact, and the separator has spiral grooves or a diametrical channel with through holes on the inside of the surface, while the clutch connected to the differential case by splines is included in the device, resting on a Belleville spring with rated force and pressing the separator to a stationary clip.

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