Abstract: When, with engine kept stopped, driven road wheels are turned, the toroidal type continuously variable transmission is suppressed from shifting toward a higher speed side. That is, when, with the engine kept stopped, the road wheels are turned in a reverse direction due to a traction of a motor vehicle with its front end facing backward, an extra oil pump driven by the road wheels produces an oil pressure which is applied to a hydraulic servo mechanism to keep a speed change ratio at a lower speed side. While, when, with the engine kept stopped, the road wheels are turned in a forward direction due to a traction of the motor vehicle with its front end facing forward, the oil pressure produced by the extra oil pump is not practically used. Under this condition, a biasing spring suppresses a servo piston from moving in a direction to bring about a speed change ratio for the higher speed side.

Abstract: In a toroidal continuously variable transmission, a primary oil pump is driven by an engine, whereas a secondary oil pump is driven in response to rotation of a road wheel. A hydraulic servo mechanism is connected to a trunnion to create an offset of the trunnion from a neutral position for a tilting motion of the power roller. Also provided is a hydraulic system that supplies the hydraulic pressure discharged from the secondary pump to the hydraulic servo mechanism to prevent the offset of the trunnion in the trunnion-axis direction, corresponding to an upshift, occurring owing to rotation of the road wheel in a stopped state of the engine. A modulated hydraulic pressure, which is constantly produced by the hydraulic system during operation of the engine, acts to hold the secondary pump at either of an inoperative state and an unloaded condition during the operation of the engine.

Abstract: In a toroidal continuously variable transmission, a primary oil pump is driven by an engine, whereas a secondary oil pump is driven in response to rotation of a road wheel. A hydraulic servo mechanism is connected to a trunnion to create an offset of the trunnion from a neutral position for a tilting motion of the power roller. Also provided is a hydraulic system that supplies the hydraulic pressure discharged from the secondary pump to the hydraulic servo mechanism to prevent the offset of the trunnion in the trunnion-axis direction, corresponding to an upshift, occurring owing to rotation of the road wheel in a stopped state of the engine. A modulated hydraulic pressure, which is constantly produced by the hydraulic system during operation of the engine, acts to hold the secondary pump at either of an inoperative state and an unloaded condition during the operation of the engine.

Abstract: When, with engine kept stopped, driven road wheels are turned, the toroidal type continuously variable transmission is suppressed from shifting toward a higher speed side. That is, when, with the engine kept stopped, the road wheels are turned in a reverse direction due to a traction of a motor vehicle with its front end facing backward, an extra oil pump driven by the road wheels produces an oil pressure which is applied to a hydraulic servo mechanism to keep a speed change ratio at a lower speed side. While, when, with the engine kept stopped, the road wheels are turned in a forward direction due to a traction of the motor vehicle with its front end facing forward, the oil pressure produced by the extra oil pump is not practically used. Under this condition, a biasing spring suppresses a servo piston from moving in a direction to bring about a speed change ratio for the higher speed side.

Abstract: A toroidal type continuously variable transmission includes trunnions (4) formed with shoulder portions (40) which oppose an upper link (5) and a lower link (6), and projections (50) on the links (5, 6) which can slide on the shoulder portions (40) when the links (5, 6) perform swinging movement. Along with forming the trunnions (4) in single units by forging, step portions (4B) are arranged between the shoulder portions (40) and sloping portions (45) of the offset portions (4A). Planar portions (40A) are formed in the shoulder portions (40) which can slide on the projections (50) by cutting or grinding so that their radiuses R from the rotation axes (4C) up to the end portions of the step portions (4B) are set in advance.

Abstract: In a toroidal type continuously variable transmission, shoulder portions are formed on a trunnion which opposes an upper link or a lower link, and projecting portions are formed on the links which slidably contact the shoulder portions when the links execute swinging movement. The end portions of the projecting portions which slidably contact the shoulder portions are formed with arcuate faces.

Abstract: A preloading mechanism (16) of a toroidal continuously variable transmission applies a predetermined preload to disks (1a, 1b, 2a, 2b) by belleville springs (9a, 9b). The input disk (1b) displaces in such a compressing direction of the belleville spring (9a) as the speed ratio increases. The displacement of the input disk (1b) is limited by a spacer (50), so the clearance (S) of the belleville springs (9a, 9b) is never zero and a large force is prevented from acting on the belleville springs (9a, 9b).