GB1464101A - Vehicles - Google Patents

Abstract

1464101 Full-face disc brakes; other friction members M M HINE 8 May 1974 [10 May 1973 7 Sept 1973] 22361/73 and 42143/73 Heading F2E A hub drivably coupled to an epicyclic gear train is braked by applying a braking force to a rotatable component of the gear train. As shown in Fig. 1 a hub assembly for a road wheel comprises a hub 1 which is rigidly secured to a planet carrier 2, planet pinions 3, a stationary ring gear 4 and a sun wheel 5 on a half shaft 6. A stack of sintered metal brake plates 7 has alternate plates internally and externally toothed and engaged with an externally splined extension 5a of sun wheel 5 and an internally splined extension 2a of planet carrier 2 alternately. For braking, the plates are all moved towards the planet carrier by hydraulic, pneumatic or mechanical means not illustrated, so that when eventually relative rotation between the planet carrier and sun wheel ceases, the road wheel is stopped. In modifications, not illustrated, alternate brake plates are carried by the ring gear 5, and the remainder by either the sun wheel extension 5a or the planet carrier 2 or the hub 1. In further modifications, each of the three planet wheels carries plates, while the remaining plates are carried by one of the other components (including, as one example, an extension of the ring gear 4) or by the hub. In Fig. 5, plates 71 on a splined extension 3a of a planet pinion 3 are interleaved with circular plates 73 slidable axially on dowels 10 extending from a cover-plate 9 of the hub 1; actuation is by a mechanism 11. The same features are repeated for the other planet pinions. Cover-plate 9 is removable. In Fig. 3 the planet pinions 3 are indirectly locked for braking by providing each with a set of circular plates 71 interleaved with a common stack of floating plates 72 each of which is of tri-lobular shape. In general, a third brake member or set of members may be moved, for braking, into engagement with brake members or sets of members carried by any two relatively movable parts respectively. Brake plates may be dispensed with; instead, one or more components of the gear train may have surfaces covered with frictional material or be formed from a frictional material and may be displaced axially for direct frictional engagement for braking. Brake actuation may be by hydraulic cylinders supplied through ducts in the hub shaft; an axially movable sleeve rotatable with the shaft and sun-wheel having projections extending through the latter; or a cam mechanism operated by pins projecting from a sleeve which can perform limited rotational movement with respect to the shaft. The brake may be located nearer to the vehicle centre-line than is the gearing so that elements of the latter must be removed for brake servicing. The road wheel may be free running or gear driven by the vehicle engine.