RU2728881C1 - Differential lock coupling - Google Patents

Abstract

FIELD: machine building.SUBSTANCE: invention relates to toothed clutches for locking differential. Coupling consists of two half-couplings with end teeth (1), movable half-coupling (2) installed on splines of semi-axle (3) and fixed half-coupling (40) connected or combined with cup (5) of differential. In the cavity at the base of end teeth (1) of the movable and fixed half-couplings (2 and 4) there are grooves (6) having the following ratio of sizes: r = from h to 5h, where: r is the half-coupling face tooth groove radius, h is the groove height made in the half-clutch end tooth base.EFFECT: increased bending strength of teeth of half-couplings.1 cl, 6 dwg

Description

The invention relates to the field of transport engineering, namely to the interwheel and center differentials of the driving axles of vehicles.

Known cam clutch of differential lock, consisting of two half-couplings, movable, installed on the slots of the differential cup, and fixed, which is used as a semi-axial gear, which has special holes on the end surface. In these holes, when the locking mechanism is turned on, special pins enter - fingers connected to the movable clutch, thereby blocking the differential (EP 0343146 A2, MPK4 F16H 57/04, F16H 1/40, publ. 23.11.1989).

The disadvantage is the complexity of this design, due to the presence of a large number of parts involved in the blocking process, high manufacturing accuracy is required, which means that the cost of parts is high.

Known differential lock clutch for transmission of torque in Volvo cars, consisting of two half couplings that have end teeth parallel to each other, movable, mounted on the splines of the axle shaft, and fixed, mounted on the slots of the differential cup and fixed from axial movement on one side by the inner ring bearing, and on the other - a retaining ring inserted into the outer annular groove of the differential cup ("Trucks VOLVO FH12. Release since 1993 Operation, maintenance and repair, ed. Tertsiya, St. Petersburg, 2004 p. 135).

Also known is the interwheel differential lock clutch, consisting of two coupling halves that have end teeth parallel to each other, movable, mounted on the splines of the axle shaft, and fixed, mounted on the slots of the differential cup and fixed from axial movement by the retaining antenna of the ring inserted into the outer annular groove fixed clutch and differential cup bore. The end teeth of both coupling halves are made at an angle to the coupling axis and parallel to each other (RU No. 175068 U1, IPC B60K 17/02 (2006.01), F16D 11/10 (2006.01), publ. 11/17/2017).

The known solutions have insufficient bending strength of the teeth, because at the base of the teeth in the places of transition to the main body of the half-couplings there are radii, which, due to their small value and a sharp transition from the tooth to the body of the coupling, create stress concentrators that lead to tooth destruction.

The problem solved by the invention is to increase the bending strength of the teeth of the half couplings.

To increase the bending strength of the teeth of the half couplings, it is necessary:

- to increase the thickness of the tooth, but this will reduce the number of teeth with constant geometric dimensions, which will lead to an increase in contact stresses on the teeth and, as a consequence, to a decrease in the durability of the couplings;

- to increase the radial dimensions of the coupling halves, which is unacceptable due to the limited space for the coupling.

The task is solved as follows.

In the differential lock clutch, consisting of two coupling halves, movable and fixed, the end teeth of which are made parallel to each other, and their thickness decreases towards the base, in addition, the end teeth of the movable and stationary coupling halves are made parallel to the coupling axis and have chamfers, and in the lower grooves are made to the point of the end teeth.

The set of distinctive features, consisting in the fact that the end teeth of the movable and stationary coupling halves are made parallel to the coupling axis and have chamfers, and grooves are made at the bottom point of the end teeth, make it possible to obtain the claimed technical result in all cases covered by the requested scope of legal protection of this invention.

The analysis of known technical solutions, carried out on the basis of scientific, technical and patent documentation, showed that the set of essential features of the proposed technical solution is not known from the prior art.

The claimed technical solution is illustrated by the following drawings:

fig. 1 - differential lock clutch assembly, general sectional view;

fig. 2 - clutch in the on state, sectional view of the assembly;

fig. 3 - half-coupling, view of the groove;

fig. 4 - movable half-coupling in axonometric projection;

Fig. 5, 6 is a view of the end part of the coupling halves with the teeth being cut by the cutting head or by milling.

The differential lock clutch consists of two coupling halves with end teeth 1, parallel to each other, a movable coupling half 2 installed on the splines of the axle shaft 3 and a fixed coupling half 4, connected or combined with the differential cup 5. In the depression at the base of the end teeth 1 of the movable and stationary coupling halves 2 and 4, grooves 6 of a certain size and shape are made.

The teeth 1 of the coupling halves 2 and 4 can be made either by milling around a circle with a radius R coinciding with the radius of the machining cutter (Fig. 5), or by milling along a straight line (Fig. 6).

The aspect ratio of the groove of the clutch teeth is shown in FIG. 4:

r = h to 5h, where:

r is the radius of the groove of the half-coupling end tooth;

h is the height of the groove made at the base of the half-coupling end tooth.

This size ratio was chosen empirically, and corresponds to the highest bending strength of the coupling half teeth.

The differential lock clutch works as follows.

In the initial state, there is a gap between the teeth of the movable coupling half 2 and the fixed half of the coupling 4, which ensures free rotation with different angular velocities of the cup 5 of the differential and the half-axis 3.

When the differential lock mechanism is turned on (not shown), the movable half-coupling 2 moves along the half-axis 3. The teeth of the movable half-coupling 2 and the stationary half-coupling 4 engage, providing joint rotation of the differential cup 5 and the half-axis 3 with the same angular speed, thereby blocking the differential. Thereafter, bending stresses arise in the cavity at the base of the end teeth 1 of the movable coupling half 2 and the stationary coupling half 4 at a significant torque. But since in this place of maximum stresses there is a groove 6, the maximum stresses are evenly redistributed, which contributes to their significant reduction in the dangerous section of the teeth. This increases the strength of the teeth and hence the strength of the coupling halves.

The declared coupling has a simple reliable design and high load capacity.

The technical solution is possible for implementation on standard technological equipment using modern technologies and materials.

Claims (1)

The differential lock clutch, consisting of two coupling halves, movable and fixed, the end teeth of which are made parallel to each other, and their thickness decreases towards the base, characterized in that the end teeth of the movable and stationary coupling halves are parallel to the coupling axis and have chamfers, and in the lower grooves are made to the point of the end teeth.

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