| 摘要 |
1487417 Friction gearing S R WOOD 18 Dec 1974 [4 Jan 1974] 54647/74 Heading F2Q In an epicyclic friction drive of fixed velocity ratio, Fig. 1, equally-spaced rollers 31 make rolling contact, both with a track 32 on a shaft 33 and with the inner surface of a radially contractible helicoidal element 26, which is supported under inwardly-directed pressure by a series of annular segments 19, each segment being under pressure from an adjacent component 17, and each roller 31 is rotatably mounted on a pin 38 in a manner permitting some floating displacement, in a radial direction with respect to the common shaft axis, of each roller axis, thereby ensuring that radial pressure is exerted at the surfaces in rolling contact, so as to maintain tractive engagement. The helicoidal element 26 has at each end a tab 27, Fig. 5, and each segment 19 has a tab 24, which together key these members against rotation. Each roller pin 38 with needle bearings 34, has an eccentrically offset shank portion 36, Fig. 2, rotatably mounted in an arm 41 projecting from the body 43 of a planet carrier member 42, which in turn is secured by screws 45 to shaft 44. Each segment 19 has outward conical portions 21 which are subjected to an inwardly-directed wedging action by an inward conical surface 18 of a sleeve 17 under axial pressure from springs 20, against an opposing face of a ring 5, fixed within the housing formed by members 1, 2 and 3, Fig. 1. In an alternative embodiment, Fig. 3 (not shown), the roller has two integral sections of different diameters, axially separated, providing one rolling surface engaging only the helicoidal outer race, and a separate rolling surface engaging only the shaft inner race. |
