IMPROVEMENTS IN OR RELATING TO TRANSMISSIONS OF THE TOROIDAL-RACE ROLLING-TRACTION TYPE

摘要

A roller control system for a continuously-variable-ratio transmission of the toroidal race, rolling traction type, in which rollers (60) of variable orientation transmit traction between a part-toroidal race (85) formed on an input disc (61) and a similar race (87) formed on a coaxial output disc (62). Each roller is mounted to rotate about a fixed centre (66) and a fixed axis (58) within a rigid carriage (67), one end of which contacts operating mechanism reciprocable over a predetermined stroke of operating movement and operable to apply a control force to the carriage. The assembly of roller and carriage is located by only three contacts with adjacent structure, namely the two disc/roller contacts (86, 88) and the contact (82) with the operating mechanism. These three contacts suffice to cause the roller constantly to seek a ratio angle at which the instantaneous value of the control force is balanced by the instantaneous value of the traction forces to which the roller assembly is subjected due to the contact between the roller and the two discs, and at which the transmission is therefore in equilibrium.