US 6,129,643 AGranted

Variable diameter pulley

AssigneeKoyo Seiko Co., Ltd.

InventorsTakao Tamagawa, Toyohisa Asaji, Shinji Yasuhara, Yasuhiko Hasuda

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Abstract

A variable diameter pulley comprises a pair of pulley main bodies (18, 19) connected to a rotating shaft (15), and a power transmission ring (20) interposed between the pulley main bodies. A belt (2) is passed around an outer periphery of the power transmission ring (20). The power transmission ring (20) is made eccentric relative to an axis (15a) of the rotating shaft (15) so as to be varied in its contact diameter (D). Both pulley main bodies (18, 19) are threadedly connected to the rotating shaft (15) by a torque cam mechanism (T) composed of a pair of thread connection mechanisms, which are inversely threaded to each other. Torque for effecting rotation of the respective pulley main bodies (18, 19) relative to the rotating shaft (15) is converted into a force, which causes both pulley main bodies (18, 19) to approach each other in equal amounts of stroke.

Claims23

Dependent claims

A pulley with a variable effective radius with respect to a belt stretched therearound, the pulley comprising:

a rotation shaft;
a pair of annular pulley main bodies fitted around said rotation shaft for rotating with the shaft about an axis in a predetermined rotation direction, said main bodies having respective opposing tapered torque transmission faces, and defining, therebetween a retention groove for holding the belt;
first coupling means coupling the pair of pulley main bodies to each other in a co-rotatable manner while permitting the pair of pulley main bodies to synchronously move relative to each other in an axial direction;
biasing means biasing the pair of pulley main bodies toward each other;
and
a pair of second coupling means coupling the pair of pulley main bodies to the shaft for torque transmission thereto,
the pair of second coupling means including a pair of conversion mechanisms converting rotational movements of the corresponding pulley main bodies relative to the shaft into axial movements of the corresponding pulley main bodies so as to move the pair of pulley main bodies synchronously toward each other by equal stroke amounts in cooperation with the first coupling means.

4 more elements

A pulley with a variable effective radius with respect to a belt stretched therearound, the pulley comprising:

a rotation shaft;
a pair of annular pulley main bodies fitted around said rotation shaft for rotating with the shaft about an axis in a predetermined rotation direction, said main bodies having respective opposing tapered torque transmission faces, and defining therebetween a retention groove for holding the belt;
first coupling means-coupling the pair of pulley main bodies to each other in a co-rotatable manner while permitting the pair of pulley main bodies to axially move relative to each other;
biasing means biasing the pair of pulley main bodies toward each other;
a pair of second coupling means coupling the pair of pulley main bodies to the shaft for torque transmission thereto,
the pair of second coupling means including a pair of conversion mechanisms converting rotational movements of the corresponding pulley main bodies relative to the shaft into axial movements of the corresponding pulley main bodies so as to move the pair of pulley main bodies toward each other by equal stroke amounts;
and
an annular power transmission member around which the belt is stretched, said transmission member being circular and being formed of resin;
wherein the power transmission member is held between the pair of torque transmission faces in a state where the power transmission member is movable eccentrically with respect to said axis, whereby a torque is transmitted between the belt and the pair of pulley main bodies via the power transmission member.

6 more elements

Dependencies are inferred from the claim text.