Abstract: Six planets in a planetary gear are arranged in groups of two each wherein the planets of two groups are similarly spaced, the spacing of the two planets in the third group is larger but still smaller than the spacing from group to group. The radial lines of symmetry of the three groups are angularly spaced by 120.degree..

Abstract: A play-free planetary drive includes a sun gear and an internal gear between which planetary gears revolve as they rotate. The planetary gears are slightly beveled. The sun gear and the internal gear also are beveled, so that the bevel of the sun gear and of the internal gear match that of the planetary gears. With this arrangement of the gears, the sun gear and the internal gear are urged axially against the planetary gears, meshing into them until play has been eliminated. The internal gear is non-rotatably mounted to the housing, but is permitted to shift slightly radially to accommodate radial run-out of the planetary gears. Likewise, the sun gear is permitted to shift slightly radially to accommodate radial run-out of the planetary gears. The radial accommodation thus provided achieves a degree of load equalization among the planetary gears.

Abstract: The rolls in a straightening machine are arranged in an upper and a lower row each being associated with a gear, and these gears establish groups of three wherein one gear pertains to one row and drives the two others pertaining to the respective other row. The one gear of each group is on a shaft that is driven by a larger gear and these larger gears are correspondingly arranged in two rows. One of these larger gears receives driving input through a speed reducing gear from a drive motor, and meshes two of the larger gears but of the respective other row. A bypass gear drivingly links that one larger gear with a fourth one but being associated with the same row. The fourth and one of the two gears mesh with play.