Abstract: A low speed high torque motor-gear reducer assembly is disclosed of the type having a first gerotor (motoring gerotor) including a ring member (41) having (N+1) internal teeth (47) and a star (49) having (N) external teeth. A second gerotor (reduction gerotor) includes a ring (85) having (M+1; wherein M does not equal N) internal teeth (89) and a star (91) having (M) external teeth. The internally-toothed portion of the second gerotor is fixed by means of a flange (81) to an output shaft (25). Pressurized fluid is communicated only to the motoring gerotor whereby the output shaft rotates at a speed reduced from the speed of rotation of the star (49) by a reduction factor R wherein: ##EQU1## In accordance with one embodiment of the invention, a third gerotor (support gerotor) is included having a star (103) identical to the star (49) and being in engagement with an intermediate shaft (97) such that the stars (49) and (103) orbit and rotate in unison.