Disclosed is a fluid damping system for a planetary traction drive designed for a driven turbocharger on an engine. The planetary traction drive has a plurality of double roller planets that are each supported by two planet hearings, one at each end of the double roller planet. Each planet bearing has a fluid damping system that consists of a radial squeeze film damper that feeds fluid to an axial squeeze film damper to absorb vibrations and dissipate kinetic energy in the planetary traction drive.

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 a 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 high ratio traction drive transmission includes a sun roller, a traction ring, a plurality of traction planets in contact with the sun roller and the traction ring, at least one reaction roller in contact with at least one of the traction planets, and a carrier assembly coupled to at least one of the traction planets and the at least one reaction roller. The sun roller has a first longitudinal axis and the traction ring is aligned coaxially with a second longitudinal axis, wherein the first longitudinal axis is radially offset from the second longitudinal axis.

A gearbox is disclosed. The gearbox can have planetary gears. Each planetary gear can revolve around a rotational center of itself while concurrently revolving around a rotational center of the gear system as a whole. The gearbox can be used to deliver rotational output energy at a right (or other angle) from the direction of a received input energy.

A gearbox is disclosed. The gearbox can have planetary gears. Each planetary gear can revolve around a rotational center of itself while concurrently revolving around a rotational center of the gear system as a whole. The gearbox can be used to deliver rotational output energy at a right (or other angle) from the direction of a received input energy.

A speed reducer drive can drive an output relative to a fixed ring using planet rollers having different diameter in contact with the output and fixed ring. Elements of the device can be formed of axially arranged segments for ease of construction. Backlash may be removed by manipulation of the drive before tightening segments of the rollers to fix the segments together by friction. The rolling contacts between elements can include a mix of geared contacts for better torque and ungeared contacts to act as bearing surfaces. Geared or ungeared surfaces may be tapered. Elements may be axially adjustable relative to each other, allowing backlash to be removed in combination with taper.

A speed reducer drive can drive an output relative to a fixed ring using planet rollers having different diameter in contact with the output and fixed ring. Elements of the device can be formed of axially arranged segments for ease of construction. Backlash may be removed by manipulation of the drive before tightening segments of the rollers to fix the segments together by friction. The rolling contacts between elements can include a mix of geared contacts for better torque and ungeared contacts to act as bearing surfaces. Geared or ungeared surfaces may be tapered. Elements may be axially adjustable relative to each other, allowing backlash to be removed in combination with taper.

An epicyclic traction drive transmission, including a carrier having a central axis, a sun shaft rotationally mounted within the carrier, a plurality of planet rollers mounted on the carrier, and an outer ring. Wedge rollers associated with each planet roller are located in a wedging slot defined between the ring and the planet roller. A resistance mechanism is provided so that the wedge roller's movement into the wedging slot is resisted by a force that is transferred to the carrier.

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 a 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 traction device including a ring member, a carrier, and a sun member and an electric motor, wherein the electric motor is coupled to at least one of the ring member, the carrier, and the sun member.