Epicyclic transmission

An epicyclic transmission with steplessly-variable speed control including:

• a housing;
• a drive shaft extending within said housing;
• a driven shaft extending within said housing;
• a planet carrier in said housing and mounted on said drive shaft for rotation by the latter;
• a plurality of planet wheels in the form of tapered rollers which are supported for rotation by said planet carrier and are spaced angularly from one another about the axis of rotation of said planet carrier, said planet wheels having a larger frusto-conical portion and a smaller frusto-conical portion adjacent the larger base of the larger frusto-conical portion, whereby the radially external generatrices of said larger frusto-conical portions extend substantially parallel to the axis of rotation of said planet carrier;
• respective rolling bearings which support said planet wheels for rotation on said planet carrier;
• a governing annulus locked for rotation with said housing and having its internal surface in rolling contact with the surfaces of said larger frusto-conical portions of said planet wheels;
• adjustment means for axial displacement of said governing annulus along said larger frusto-conical portions of said planet wheels;
• a driven annulus rotatable coaxially with said planet carrier for rotating said driven shaft, said annulus having an internal conical surface complementary to the surfaces of said smaller frusto-conical portions of said planet wheels, and
• means for pressing together in pressure contact the surface of said smaller frusto-conical portions of said planet wheels and said complementary conical surface of said driven annulus, and the surfaces of said larger frusto-conical portions of said planet wheels and the internal surface of said governing annulus,
• the improvement comprising said transmission further including a freely-rotatable sun wheel in the form of a sleeve which is coaxial with said planet carrier and has two axially spaced bearing surfaces, and each said planet wheel having two bearing surfaces which are complementary with said axially spaced bearing surfaces and are in rolling contact therewith, and
• wherein said means for pressing together in pressure contact said smaller frusto-conical portions of said planet wheels and said complementary conical surface of said driven annulus, and said larger frusto-conical portions of said planet wheels and said internal surface of said governing annulus, include an oleodynamic actuator.