Patent ID: 6186778
Filing Date: 2001-02-13
Classification: F16H,F27B

Abstract:
A device for driving a cylinder (1) in rotation about its longitudinal axis, said cylinder resting on raceways permitting said rotation, said device comprising:a) at least one ring gear (2) having side faces that are substantially parallel to each other and substantially radial from (perpendicular to) the cylinder axis, said gear being substantially concentric with the cylinder and being arranged outside the cylinder and connected thereto by securing means (3) capable of withstanding distance variations between the cylinder and the ring gear.b) one or more modules each comprising a rigid structure (16), even numbers of truncated rollers (4, 5) and supports (27, 21) for the truncated rollers, said truncated rollers being capable of rotating about their longitudinal axes (6, 7) and being connected to their supports through ball or plain bearings, said truncated rollers having their generators (37, 38) intersect substantially on the cylinder axis at a point (C) which is substantially the center of the ring gear and being arranged in facing pairs on either side of the side faces of the ring gear and being capable of pressing on said side faces, at least one of the rollers being a drive roller whose function is to transmit a driving force to the ring gear,c) at least one actuator (30) for each pair of rollers, capable of exerting, through the roller supports, enough direct or indirect pressure on the rollers of said pair to firmly press said rollers against the ring gear and to enable them to drive both the ring gear and the cylinder in rotation, the actuator supports and the roller supports of each module being connected to said rigid structure, which comprises means (22) allowing it to move and change direction in response to the movements and direction changes experienced by the ring gear during its operation.