Free-floating planetary transmission with reversible output

Claim 1

A transmission comprising: (a) a set of free-floating planetary elements spaced circumferentially about the transmission axis with each planetary element having a spindle disposed parallel to said axis; (b) a plurality of axially-spaced rings co-axial with the transmission axis and having rolling contact with said planetary elements to constrain said elements against the radial forces acting thereon; (c) each spindle having first, second and third planet gears mounted on the spindle and axially spaced therealong; (d) a first toothed wheel co-axial with the transmission axis and meshing with said first planet gears of said planetary elements and providing the transmission input; (e) a plurality of input gears each of which is connected via a driveshaft to a source of rotary power for rotation in a single direction and disposed in mesh with said first toothed wheel to rotate said first toothed wheel; (f) a second toothed wheel co-axial with the transmission axis and meshing with said second planet gears of said planetary elements; (g) a third toothed wheel co-axial with the transmission axis and meshing with said third planet gears of said planetary elements; (h) an output shaft; (i) clutch means selectively operable to connect one or the other of said second and third toothed wheels to said output shaft; (j) brake means selectively operable to prevent rotation of that one of said second and third toothed wheels not connected to said output shaft thereby providing the reaction force on each planetary element for providing rotation of said output shaft alternately in opposite directions; and (k) the three planet gears of each planetary element being so spaced apart axially along their spindle that the net turning moment exerted by the input, output and reaction forces tending to tilt each planetary element out of its radial plane, including the transmission axis, is substantially zero.