Abstract: A continuously variable transmission of the half-toroidal type, comprising an input shaft connected to a drive source, an input disc supported on the input shaft, an output disc supported on the input shaft and opposed to the input disc, and a power roller provided between the input and output discs for rocking motion and in rolling contact with the discs. In this transmission, the discs are shaped so that (R.multidot.d)/(D.multidot.t) is given by 0.5<(R.multidot.d)/(D.multidot.t)<1.5, where R is the radius of curvature of each traction surface, D is the distance between the centers of curvature, d is the inside diameter of each disc, and t is the thickness of each disc.

Abstract: The amounts of displacement of trunnions installed in first and second cavities are made equal to each other irrespective of the amount of resilient deformation. Also, if the worst should happen, the stability of the running of an automobile is secured. The supply and discharge of pressure oil to first and second actuators for displacing the trunnions installed in the first and second cavities are effected by first and second control valves independent of each other. A value is included for controlling so that the difference between oil pressure fed into the first actuator and oil pressure fed into the second actuator may not become great.

Abstract: For a toroidal type continuously variable transmission, the end portion of a radial needle bearing provided for a trunnion is protruded from the inner face of the trunnion. Also, the inner face of the trunnion is made substantially flat. Therefore, the processing of the trunnion is made easy, and the holder of the thrust needle bearing can be easily positioned simultaneously. Also, the structure is arranged to enable the recess formed on the trunnion to engage with the extrusion formed on the holder, thus preventing any plane pressure from being exerted excessively on the rolling surface of the needles of the thrust needle bearing, as well as preventing the needles from falling out of the pockets of the holder.

Abstract: A sufficient quantity of lubricating oil can be sent into a radial needle bearing and a thrust ball bearing supporting a power roller. The lubricating oil is discharged into a gap space through a send-in side oil supply path formed in a trunnion, and is sent into a receiving side oil supply path in a pivotal support shaft portion. A thrust sliding bearing having a through-hole is provided in the gap space. The downstream end opening of the send-in side oil supply path and the upstream end opening of the receiving side oil supply path are located inside the through-hole.

Abstract: In order to improve the transmission efficiency of a toroidal type continuously variable transmission by reducing the dynamic torque loss of an antifriction bearing, a first output gear is constituted by a pair of helical gears of which the directions of inclinations are opposite to each other, and a second output gear is constituted by a double helical gear. By this construction, a thrust force created in the meshing portion between the first and second output gears is offset and the dynamic torque loss of the antifriction bearing is reduced.

Abstract: For a toroidal type continuously variable transmission, the end portion of a radial needle bearing provided for a trunnion is protruded from the inner face of the trunnion. Also, the inner face of the trunnion is made substantially flat. Therefore, the processing of the trunnion is made easy, and the holder of the thrust needle bearing can be easily positioned simultaneously. Also, the structure is arranged to enable the recess formed on the trunnion to engage with the extrusion formed on the holder, thus preventing any plane pressure from being exerted excessively on the rolling surface of the needles of the thrust needle bearing, as well as preventing the needles from falling out of the pockets of the holder.

Abstract: A half-toroidal-type continuously variable transmission capable of transmitting great power has two sets of discs, which each include an input side disc and an output side disc, and two sets of three power rollers, one between each of the sets of discs, thus providing a total of six power rollers. Trunnions supporting the power rollers are supported by support posts. Loads applied to the support posts are transmitted to fixing rods and connecting rods and are offset in those rods.

Abstract: A toroidal type continuously variable transmission is arranged to support one disc on the input side, facing a pressure device, on the outer circumference of an input shaft through a needle bearing. The other disc on the input side is supported on the input shaft by means of a spline coupling and a flange. A cam board which constitutes a pressure device is supported on the outer circumference of the input shaft through a ball spline. Disc springs are installed between one face of the cam board and a loading nut. In this way, the number of difficult processing steps and the degree of required precision can be reduced at the same time, hence making it possible to implement the reduction of the manufacturing costs.

Abstract: In order to prevent strong bending stress given to outer rings of thrust ball bearings of power roller assemblies and to improve the durability of the outer rings, a toroidal-type continuously variable transmission has thrust needle bearings which absorb thrust load given to the outer rings as well as allow the outer rings and corresponding trunnions to be shifted from each other. Preferably, the entire circumference of the pitch circle of the balls of each thrust ball bearing overlaps with a load-absorbing region, which is one or more annular and/or arcuate regions having the same width as the needles of needle bearings radially arranged in said regions in order to absorb thrust load.

Abstract: In a vehicle having first and second wheels (e.g., front and rear wheels) to be driven with a speed difference, the wheels are driven by a toroidal type continuously variable transmission having a single input shaft and which is effective to accommodate the speed difference between the first and second wheels without a separate differential for such purpose.