GB881045A - Improvements relating to differential-drive devices - Google Patents

Abstract

881,045. Balance gear. DAIMLER-BENZ A.G. July 1, 1958 [July 6, 1957], No. 21107/58. Class 80 (2). A slip-limiting device in a motor vehicle differential gear of the kind wherein balls or blocks 16 caged in an input crown-wheel 12 engage different pitched undulating cam tracks 17, 18 in rings 19, 28 fast on two outputs, which device may be interposed between the two outputs or, as shown, between the input and one output, comprises undulating tracks 26, 25, of staggered equal wavelengths, provided respectively in the ring 28 and in a further ring 27 fast on the same output, and one or more ball or roller pistons 21 preferably pitched at one at one and a half wavelengths of the track undulations in axial or radial cylinders 22 of an input fast cage 23 interposed between the rings 28, 27, the said tracks and cage faces forming one or more cells 30, 31, such that on relative rotation between the tracks and the cage arising from relative output rotation contained liquid, preferably oil, is displaced by the piston 21 between the cells 30, 31 against a throttling resistance determined by the various clearances. Conical surfaces 33 between an input housing 13 and the output ring 27 are engaged for frictional resistance between the two output rings 19, 28 by axial thrust from the balls 16 which is dependent on the input tangential driving force and the pitch of the cam tracks 17, 18 and independent of the difference in output speeds, the opposing axial thrust being taken up between the ring 19 and the input housing 13. Further axial thrust urging the rings 19, 27 against the housing 13 may be provided hydraulically by pressurized liquid conducted from the cells 30, 31 to act between faces 40, 41 respectively of the rings 19, 28. The relative rotation between the cage 23 and the rings 28, 27 may be increased by suitable transmission means. Reference has been directed by the Comptroller to Specification 782,314.