GB788105A - Locking differential - Google Patents

Abstract

788,105. Differential gear. THORNTON, R. F. Oct. 20, 1954, No. 30246/54. Class 80 (2). A planetary differential gear is rendered selflocking by coned friction clutch surfaces 94, 96 between the respective output side-wheels 74, 76, splined on vehicle axle shafts, and an input casing 10, carrying the usual ring gear, such surfaces being brought into engagement by complementary camming surfaces 24 on radial pins 34 &c., carrying the two pairs of planet pinions 58 &c., and in casing apertures 18 in which the pins have limited circumferential movement in response to transmitted torque, the camming surfaces being oppositely directed for pairs of pins on diameters at right-angles. In operation equalized forward or reverse torques cause the respective pairs of pins 34 &c. to thrust leftwards and rightwards on their planet pinions 58, and thence, through trackways 90, on the side wheels 74, 76 to engage the friction clutch surfaces 94, 96, thus locking the differential gear. During a turn the accelerating tendency of the outside wheel causes the planet-pins 34 &c. to advance relatively to the input casing 10, thus releasing the cammed clutch pressure for normal differential action as required. A central spring 72 pre-loads the clutch surfaces. In Fig. 8, not shown, the input casing is in three pieces permanently welded together and opposite planet-pins are integrally connected by offset central bridges.