GB471325A - Differential or balance mechanism - Google Patents

Abstract

471,325. Differential gearing. LFIELD, R. J. Feb. 3, 1937, No. 4497. [Class 80 (ii)] A differential mechanism comprises a planet carrier and casing 12 driven through bevel gearing 11 and co-axial internally-toothed driven wheels 16a, 16b on the half-axles 17, 17. The planets comprise pairs of intermeshing pinions 13a, 13b which also mesh respectively with the driven wheels 16a, 16b. For limiting the differential effect and preventing the half-axles 17, 17 from being driven at different speeds the ratio of the greater to the less of which exceeds a predetermined value, two additional gears 26 on sleeves 20a, 20b are provided which are geared to the planet pinions 13a, 13b respectively, and are prevented from backward rotation by one-way locking devices (not shown) coacting with adjacent surfaces 21 on the outer ends of the sleeves 20a, 20b. Thus for equal speeds of the axles 17 and for speeds within the predetermined ratio the sleeves 20a, 20b rotate freely in a forward direction. When this speed ratio is exceeded however, the sleeve co-operating with the faster moving axle tends to rotate backwards but is prevented from doing so by its respective oneway locking device. Thus the normal differential effect is allowed for, but an excessive differential effect such as "spinning" is prevented. The locking devices which are associated with a stationary part may include a common outer member and provision may be made for releasing the locking devices to allow of a drive in the reverse direction when required. In a modification, one of the driven axle gears comprises a sun pinion and stepped compound planets are used. In another modification, the planet carrier is secured to one of the driven axles and the driving element comprises an internal annulus.