A speed reducer including: an input shaft; a first barrel cam; a first output table; an intermediate shaft; a second cam; and a second output table, in the first output table, the plurality of first cam followers being provided concentrically around a rotation center position of the intermediate shaft, concerning a certain first cam follower among the plurality of first cam followers, when a center position of the certain first cam follower when the certain first cam follower has been moved to a farthest end on one side in the up-down direction is defined as a reference position, a center position of the first barrel cam being shifted to another side in the up-down direction with respect to the reference position, an engagement center position in the front-rear direction between an engagement start position and an engagement end position being shifted either of forward and rearward with respect to the reference position.

Disclosed is an adjustable ring shim for a planetary traction drive designed for a driven turbocharger on an engine. The adjustable ring shim has two parts that interface through a ramp feature to provide an ability to vary the overall width of the ring roller assembly of the planetary traction drive. This adjustability in the width of the ring roller allows for setting a desired preload force on the traction surfaces of the traction drive during assembly, even with variation in manufacturing of the different parts of the traction drive.

Disclosed is an adjustable ring shim for a planetary traction drive designed for a driven turbocharger on an engine. The adjustable ring shim has two parts that interface through a ramp feature to provide an ability to vary the overall width of the ring roller assembly of the planetary traction drive. This adjustability in the width of the ring roller allows for setting a desired preload force on the traction surfaces of the traction drive during assembly, even with variation in manufacturing of the different parts of the traction drive.

In a cycloid transmission a second input side eccentric cam and a first output side eccentric cam are integrally fixed to a rotary shaft to be eccentric in the same phase, a first input side eccentric cam is fixed to the rotary shaft so that the first input side eccentric cam is eccentric in a phase different from that of the second input side eccentric cam and that of the first output side eccentric cam, a second output side eccentric cam is rotatably attached to the rotary shaft, a second input side cycloid gear and a first output side cycloid gear are integrally formed to be rotated in synchronism with each other in the same phase, and a first input side cycloid gear is connected to the second output side cycloid gear by a connection member to be rotated in synchronism with each other in the same phase.

In a cycloid transmission a second input side eccentric cam and a first output side eccentric cam are integrally fixed to a rotary shaft to be eccentric in the same phase, a first input side eccentric cam is fixed to the rotary shaft so that the first input side eccentric cam is eccentric in a phase different from that of the second input side eccentric cam and that of the first output side eccentric cam, a second output side eccentric cam is rotatably attached to the rotary shaft, a second input side cycloid gear and a first output side cycloid gear are integrally formed to be rotated in synchronism with each other in the same phase, and a first input side cycloid gear is connected to the second output side cycloid gear by a connection member to be rotated in synchronism with each other in the same phase.

A variety of transmissions, and improvements thereof, are provided having improved efficiency and other benefits. The transmissions include one or more inner members that are driven by one or more cams or other means to engage in precessional rotation about an axis of rotation that, itself, orbits about a primary axis of rotation. A plurality of shaped rollers are in contact with shaped cutouts on the inner member(s) and on a ground member such that an input rotation/torque applied via the cam is realized as an output rotation/torque at an output member that is coupled to the inner member(s). Tire rollers and contact surfaces are shaped such that the rollers engage in rolling motion relative to the contact surfaces, providing improved efficiency. Multiple inner members, and corresponding sets of shaped rollers, can be provided to increase power capacity, reduce torque ripple, reduce wobble, or provide other benefits.

A variety of transmissions, and improvements thereof, are provided having improved efficiency and other benefits. The transmissions include one or more inner members that are driven by one or more cams or other means to engage in precessional rotation about an axis of rotation that, itself, orbits about a primary axis of rotation. A plurality of shaped rollers are in contact with shaped cutouts on the inner member(s) and on a ground member such that an input rotation/torque applied via the cam is realized as an output rotation/torque at an output member that is coupled to the inner member(s). Tire rollers and contact surfaces are shaped such that the rollers engage in rolling motion relative to the contact surfaces, providing improved efficiency. Multiple inner members, and corresponding sets of shaped rollers, can be provided to increase power capacity, reduce torque ripple, reduce wobble, or provide other benefits.

To provide a frictional drive unit that can arrange drive rollers with high density and facilitate an attachment operation of the drive rollers, a frictional drive unit 2 includes a pair of drive disks 4, a plurality of drive rollers 5 rotatably supported by an outer circumferential portion of each drive disk, a pair of actuators 8 configured to independently rotate the pair of drive disks, and an annular main wheel 7 arranged between the pair of drive disks and coming into contact with the drive rollers. Each drive roller includes a roller shaft 41 and a round roller body 42 provided on an intermediate portion of the roller shaft. Each drive disk includes plural pairs of bearing grooves 45 each receiving both ends of the roller shaft of each drive roller. Each bearing grooves open toward the main wheel.

To provide a frictional drive unit that can arrange drive rollers with high density and facilitate an attachment operation of the drive rollers, a frictional drive unit 2 includes a pair of drive disks 4, a plurality of drive rollers 5 rotatably supported by an outer circumferential portion of each drive disk, a pair of actuators 8 configured to independently rotate the pair of drive disks, and an annular main wheel 7 arranged between the pair of drive disks and coming into contact with the drive rollers. Each drive roller includes a roller shaft 41 and a round roller body 42 provided on an intermediate portion of the roller shaft. Each drive disk includes plural pairs of bearing grooves 45 each receiving both ends of the roller shaft of each drive roller. Each bearing grooves open toward the main wheel.

A structure is achieved capable of ensuring excellent transmission efficiency while preventing the occurrence of gross slipping at traction portions.

A pressing device 9 rotationally drives a cam disk 21 by a pressing force adjusting motor 23, which causes an annular roller element 6a of a pair of annular roller elements 6a, 6b to displace in the axial direction. A controller 31, by adjusting the rotational drive of the pressing force adjusting motor 23, adjusts the surface pressure at the traction portions between rolling surfaces 16 of planetary rollers 7 and an inner-diameter side rolling contact surface 5 of an input shaft 3 and outer-diameter side rolling contact surfaces 12a, 12b of the pair of annular roller elements 6a, 6b to a target value.