A method of controlling a continuously variable electric drivetrain (CVED) including a high ratio traction drive transmission and at least one of a first motor-generator and a second motor-generator is disclosed. The method includes the steps of receiving an output speed, determining a kinematic output speed, and determining a slip state of the high ratio traction drive transmission based on a comparison of the output speed to the kinematic output speed.

A planetary roller transmission includes: a fixed ring; a sun shaft; a plurality of planetary rollers; a carrier that has a plurality of support shafts that support the planetary rollers via bearing portions and that revolves together with the planetary rollers; and an annular flange ring provided on one side, in the axial direction, of the fixed ring and the planetary rollers. The inside diameter of the flange ring is smaller than the diameter of a circumscribed circle circumscribed by bearing portions which are arranged in the circumferential direction. An oil storage portion that receives oil that has climbed over the flange ring from the side of the planetary rollers is provided between a side surface of the flange ring and an inner wall surface of the housing. A passage that allows oil to permeate from the oil storage portion to the side of the planetary rollers is provided.

A speed increaser includes an annular peripheral wall rotatable with a rotation of the low-speed shaft, a high-speed shaft disposed within the peripheral wall and having a rotation axis extending in the same direction as that of the peripheral wall, and three rollers disposed within the peripheral wall and in contact with both the peripheral wall and the high-speed shaft. The three rollers are disposed at different positions along the rotation axis of the high-speed shaft with rotation axes of the three rollers extending in the same direction as the rotation axis of the high-speed shaft, and the rotation axes of the three rollers are spaced in a circumferential direction of the high-speed shaft. The three rollers are disposed so that at least part of contact areas between the high-speed shaft and the rollers is free from overlapping with each other along the rotation axis of the high-speed shaft.

A speed increaser includes an annular peripheral wall rotatable with a rotation of the low-speed shaft, a high-speed shaft disposed within the peripheral wall and having a rotation axis extending in the same direction as that of the peripheral wall, and three rollers disposed within the peripheral wall and in contact with both the peripheral wall and the high-speed shaft. The three rollers are disposed at different positions along the rotation axis of the high-speed shaft with rotation axes of the three rollers extending in the same direction as the rotation axis of the high-speed shaft, and the rotation axes of the three rollers are spaced in a circumferential direction of the high-speed shaft. The three rollers are disposed so that at least part of contact areas between the high-speed shaft and the rollers is free from overlapping with each other along the rotation axis of the high-speed shaft.

An electric phaser for dynamically adjusting a rotational relationship of a camshaft with respect to an engine crankshaft of an internal combustion engine includes an electric motor and a tapered roller drive. The tapered roller drive includes a sun, rollers, a carrier, at least one ring, and at least one load generator providing an axial load. The rollers are maintained in rolling engagement with the sun and the ring without the use of teeth. In some embodiments, the tapered roller drive is based on a fixed-sun design. In other embodiments, the tapered roller drive is based on a split ring design.

An electric phaser for dynamically adjusting a rotational relationship of a camshaft with respect to an engine crankshaft of an internal combustion engine includes an electric motor and a tapered roller drive. The tapered roller drive includes a sun, rollers, a carrier, at least one ring, and at least one load generator providing an axial load. The rollers are maintained in rolling engagement with the sun and the ring without the use of teeth. In some embodiments, the tapered roller drive is based on a fixed-sun design. In other embodiments, the tapered roller drive is based on a split ring design.

A high speed ratio drive system is formed of planet rollers, each having varying diameter, an outer fixed ring in contact with one diameter of the planet rollers, and an outer drive ring in contact with another diameter of the planet rollers. An inner drive element is provided by a sun drive roller in contact with the planet rollers or by a planet carrier. Preferably the system has an axial reflective symmetry minimizing twisting forces on the planet rollers.

Projections protruding towards a cam plate and a disc are provided on both axial side surfaces of the retainer at a plurality of positions at which phases of the projections in the circumferential direction are offset from pockets. One axial direction surface of the cam plate and the disc are formed with concave portions at portions facing the respective projections. The concave portions have an axial depth deepest at a center portion thereof in the circumferential direction and becoming shallower towards both end portions thereof.

A pivot holder of a friction-roller-type reduction gear has a pair of bearing parts configured to support a rotational shaft of an intermediate roller and having a pivot axis at an eccentric position from a center of the rotational shaft, and a bridging part configured to integrally couple the pair of bearing parts. A carrier has a holder support part configured to rotatably support the bearing parts. An interaxial distance between a center of the pivot axis and the center of the rotational shaft is equal to or smaller than a maximum radius of an outer diameter of the intermediate roller, and the center of the pivot axis is located on an applying line of a torque reaction force of transmission torque to be applied to the pivot holder.

A pivot holder of a friction-roller-type reduction gear has a pair of bearing parts configured to support a rotational shaft of an intermediate roller and having a pivot axis at an eccentric position from a center of the rotational shaft, and a bridging part configured to integrally couple the pair of bearing parts. A carrier has a holder support part configured to rotatably support the bearing parts. An interaxial distance between a center of the pivot axis and the center of the rotational shaft is equal to or smaller than a maximum radius of an outer diameter of the intermediate roller, and the center of the pivot axis is located on an applying line of a torque reaction force of transmission torque to be applied to the pivot holder.