Hypocyclic drive transmission apparatus

Claim 1

An improved hypocyclic drive transmission apparatus for reducing the rotational speed of the output of a motor and increasing the torque thereof, said improved transmission apparatus comprising: a transmission spindle shaft rotating about a central axis in a first radial direction; a circular gear having first and second sets of lug-shaped, external gear teeth, and defining an interior diameter, a pitch diameter and an outside diameter, said circular gear operatively connected to said transmission spindle shaft for rotational movement thereby; a fixedly disposed annulus gear having lug-shaped internal gear teeth, the internal gear teeth of said annulus gear engageable with the first set of external gear teeth of said circular gear upon overlap between said circular gear and said annulus gear; eccentric means fixedly mounted on said transmission spindle shaft, said eccentric means having a center defining a cam offset distance from said spindle shaft central axis, and freely mounting said circular gear on said eccentric means for maintaining said circular gear and said annulus gear in overlapping relationship, for engaging the respective gear teeth thereof, and for tracing a hypocycloid at reduced rotational speed within said annulus gear by said circular gear in a second radial direction which is opposite the first radial direction of said transmission spindle shaft, said overlap defining a point of maximum overlap; a rotatable drive hub having internally disposed lug-shaped teeth and disposed to surround a portion of said circular gear, the internal teeth of said drive hub engaging the second set of external gear teeth of said circular gear upon overlap between said circular gear and said drive hub; rotational output means connected to said drive hub for receiving the reduced rotational speed output; the first set of external gear teeth of said circular gear and the internal gear of said annulus gear being disengaged at said point of maximum overlap, and in engagement at a radial distance of greater than 0 degrees but less than 90 degrees as measured in said angular direction from said point of maximum overlap, said circular gear teeth tracing a prolate cycloid at each of said circular gear interior, pitch and outside diameters immediately prior to, during and immediately after said engagement.