GB739917A - Variable transmission - Google Patents

Abstract

739,917. Variable-speed gearing. FIAT SOC. PER AZIONI. Jan. 14, 1954, No. 1139/54. Class 80 (2). Variable-speed epicyclic friction gearing comprises three rows of interengaging balls 2, 3, 4 coacting with annular races on driving, driven and reaction members, the axial position of one of the latter relative to the other two being adjustable to vary the speed ratio. The balls 2 engage races on members 1, 6, the balls 4 engage races on a member 5 and a ring 7 freely rotatable in member 6, and the intermediate balls 3 engage a freely-mounted guide ring 9, contact being maintained by a spring 10 between members 1, 5 or by fluid-pressure or electromagnetic means. In Fig. 1, shaft 1 drives, shaft 5 is driven, and member 6 is non- rotatable. The member 6 or the assembly 1-5 is moved axially to vary the speed ratio. In Fig. 4, member 6 is rigid with the driving shaft 19, and member 5 is held against rotation in one direction by a.one-way detent 24, or alternatively is held against rotation in both directions, so that member 1 is driven forwardly or reversely as the assembly 1-5 is moved in one or other direction from central position. This gear is combined with a spur epicyclic gear cf which the sun 20 is rigid with shaft 19, annulus 12 -is rigid with member 1, and carrier 23 is rigid with the output shaft 21. The assembly 1-5 is movable axially from central position by supplying pressure fluid to one or other side of a plunger 15 on shaft 19 in a cylinder 16 in member 1 under the control of a valve operated manually or automatically under torque control, or by mechanical or electromagnetic means. The members 1, 5 may be locked together by a clutch ring 25, the member 5 being at the same time freed from restraint by the detent 24, to obtain direct drive.