Abstract: A gear including a frame, a first shaft, a first gearwheel arranged on the first shaft and in engagement with a second gearwheel mounted on a second shaft, the second shaft including bearings at both sides of the second gearwheel between the frame and the second shaft. The second shaft revolves about the bearings placed on each side of the second gearwheel. At least one spring is fitted to act with a force upon an outer race of rolling members of one of the bearings. A glide fitting is provided between a circumferential face of the outer race and the gear frame or a connected part. The force effect applied by the spring(s) is transferred through the rolling members of the bearing to the inner race of the bearing and further to the other bearing placed at the opposite side of the gearwheel whereby the play in both bearings between the rolling members and the bearing races is eliminated.

Abstract: A roll and roll-driving assembly includes an internal stationary shaft and an outer shell surrounding the internal shaft as well as a bearing structure supporting the outer shell for rotation with respect to the internal shaft. A rotary input shaft is coaxial with the stationary shaft to receive a rotary drive from an outside source. A sun gear is fixed coaxially to the rotary input shaft so as to rotate therewith, while a plurality of planetary gears which respectively have axes parallel to the axis of the input shaft and which mesh with the sun gear are uniformly distributed about the axis of the input shaft. An internal ring gear surrounds and meshes with the planetary gears while being supported exclusively thereby so that the internal ring gear can automatically center itself with respect to the plurality of planetary gears while a load is uniformly distributed along a plurality of power-transmission paths extending from the sun gear through the plurality of planetary gears to the internal ring gear.