FR2530765A1 - Limited action differential. - Google Patents

Abstract

Limited action differential, allowing a vehicle to turn in its minimum turning circle by using the "differential" function but in which the ratio of the speeds of rotation of the two output half shafts cannot be greater than a value defined during the construction of the device. It is constituted by the bases of a conventional differential, itself completed by gears which are always engaged but mounted on free wheels and which abut each of the wheel bearing half shafts. The drive obtained by the intermediary of these supplementary gears gives for example a rotational speed of the output half shafts, only representing 80 % of that obtained by the operation of a straight line differential. The invention can be used on all vehicles where there is a mechanical transmission, such as: individual cars, heavy goods vehicles, public transport vehicles, all-terrain vehicles, agricultural tractors, forestry vehicles, rail vehicles and others.

Description

ESCRIPTION
Limited action differential.

 The present invention relates to a limited-action differential making it possible, while keeping the "differential" function, to drive the two output half-shafts.

In known devices of this kind
a) - self-locking differential with cone brakes
The construction principle is similar to that of the conventional differential. However, cone brakes placed behind and rubbing against the planetary gears are added to it.

To produce a first resistance to the differential action, we spiic between the two planets, a static preliminary charge produced by springs Under torque, to this load are added the forces produced by the separation of the planets and satellites, which increases the resistance in the different (differential known as BORG-WARNER).

b) - GLAENZER POWER LOCK servo differential
Clutches are interposed between the planets and the housing but the satellites are four in number, mounted at the ends of two separate planet carrier axes whose ends instead of being cylindrical, have the shape of a cam. These satellite carriers have a certain freedom because they can mount on hiiicoSdales ramps provided in the lights of the box. Behind the planetary gearboxes, counter-planetary gearboxes receiving the thrust from the planetary gearboxes are placed. The rotation with respect to the counter-planetary gearbox is limited by a multi-disc clutch device.

in these devices various handicaps remain - construction involving elements deemed to wear
(cones, branch lines), - tendency to undergo equipped vehicles, - transmission of non-integral engine torque. If a wheel has held
dance to skate, the wheel with the best grip re
receives a torque equal to that of the wheel which tends to slip
multiplied by the transfer coefficient, one of the wheels for
therefore not to turn, - Energy absorbed by permanent friction results in
a lesser revival than that obtained by a standard differential
if that.

The device according to the invention makes it possible to avoid all of these drawbacks: - it does not involve wearing parts, - it does not require any adjustment, - it will have no effect on the behavior of the vehicle,
(no surviving couple, no torque under tacker), - it will provide mechanical training in all circumstances
of the two wheel carrier half-shafts.

 The device which is the subject of this invention in its schematic and non-limiting preferential version according to FIG. ", a double size distributor pinion" 4 "(one for driving by the pinion pinion" 2 "and an external one to drive the bell pinion" 8 "), carrying two pinions" 5 "## ### with external teeth, these pinions will be driven when the vehicle is in forward gear by means of two free wheels "6" and "7", a bell pinion "8" carrying satellites "9" which process the planetary ies " IO "and" 11 "themselves integral with the half-shafts" 12 "and 'tI% 1l, two pinions" 14 "and" 15 ", which we call counter planetary, with external teeth and driven by" 5 "and" 6 "in forward, drive themselves8 via the two freewheels" I6 "and" I7 "the two motor half-shafts" I2 "and" I3 "at a lower speed of 20% (by e xample), to that obtained in a straight line through the bell pinion "8". This lower speed of (x%) being defined by construction for a given vehicle, so as to allow it to turn with its minimum turning radius without obtaining skidding or shifting of the inner wheel.

 The device according to the invention in another schematic and nonlimiting version could be produced after figure -2-. This arrangement works on the principle of the previous one but only involves three free wheels and should result in a differential case reserving less ground clearance than the previous one.

 These devices according to the invention involve freewheels, which are known devices and some versions of which are known for their extreme robustness and longevity. Different versions of these principles are shown in figures "3" and "4" (freewheels with rollers and spring), figure "5" (freewheels with rollers without spring, the rollers of which are placed between two raceways which are not exactly concentric , which leads to exceptional longevity).

 Different other versions of freewheels exist and we wanted to present solutions offering maximum safety, but this is not a limiting goal, these devices being known and applied.

 Furthermore, the schematic assemblies shown in FIG. -I- and FIG. -2- do not involve the ball bearings, possibly ball bearings. The appropriateness or the necessity of these arrangements being well known to the designers.

Claims (8)

 R E V E N D I C A T I O N S  I - Differential with imitated action enabling the two output half-shafts to be driven in all circumstances, while retaining the "differential" function.  2 - Disl, positive according to Revenication I - characterized by the fact that the counter planets driven at a speed voluntarily lower than that of the bell pinion, drive through the freewheels the right and left half-shafts when the gear the speed of these half-trees would like to be higher (or lower) than a value defined by construction, these half-trees can still rotate faster than the counter planetary ones.  3 - Device according to claim 2 - characterized in that ies two planetary against are driven by two pinions themselves driven by a freewheeling device.  4 - Device according to claim 3 - characterized in that the freewheel device allows to have a differential function in forward and reverse.  5 - Device according to claim 3 - characterized in that the ratio of the number of teeth of the pinions marked "5" and "I4" or "6" and "I5", compared to the ratio of the numbers of teeth of pinion marked " 4 "and" 8 "limit the action (read differential in forward gear.  6 - Device according to claim 5 - characterized in that the limited action of the differential nevertheless allows the vesicle to veer with its minimum turning radius without causing the driven internal wheel or wheels to slip,  7 - Device according to claim 2 and 3- characterized in that the book wheels are known to you (wedging devices for example) and that these free wheels can be attached or be an integral part of the constituent elements.  8 - device according to claim 3 - characterized by the absence of a wear or friction part, which improves the yield