Infinitely variable transmission

Abstract

An infinitely variable transmission includes a driver shaft having a driver pulley, a driven shaft having a driven pulley, the driver and driven pulleys having fixed conical discs and movable conical discs, the movable conical discs having pressure chambers, an endless belt trained around said driver and driven pulleys, a device for supplying a fluid under pressure to the pressure chambers, a pressure regulating mechanism for regulating the fluid pressure at a prescribed pressure, and a fluid metering mechanism for regulating the amount of the fluid under the prescribed pressure in the pressure chambers. At least one of the pressure regulating mechanism and the fluid metering mechanism is disposed in the driver shaft or the driven shaft. The pressure regulating mechanism is arranged to discharge an excess amount of the fluid to a lower-pressure area when the supplied fluid pressure exceeds a prescribed level and also has passages for supplying the discharged amount of the fluid as lubricating oil to the endless belt. The fixed conical discs of the driver and driven pulleys are disposed on opposite sides of the endless belt. The fixed conical discs are arranged such that the central axis of the endless belt is inclined with respect to a line normal to pulley axes at an angle which is substantially zero at a power transmission speed ratio which is most frequently be used between the driver and driven pulleys.