Patent ID: 8663049
Filing Date: 2014-03-04
Classification: F16H

Abstract:
1. A speed reducer comprising: a sleeve-shaped rotation member having front and rear ends open, the rotation member comprising a plurality of equally spaced main rollers disposed on an inner surface; a disc-shaped rear carrier comprising a central through hole and a plurality of eccentric stepped-diameter holes equally spaced around the central through hole and connecting each other; a disc-shaped front carrier comprising a central through hole and a plurality of recesses equally spaced around the central through hole thereof; a first bearing assembly disposed between the rotation member and the rear carrier; a second bearing assembly disposed between the rotation member and the front carrier; a front wheel comprising a first through hole, a plurality of second through holes equally spaced around the first through hole, and a plurality of front rollers equally spaced on a circular edge of the front wheel, the front rollers being in contact with the main rollers; a rear wheel comprising a third through hole, a plurality of fourth through holes equally spaced around the third through hole, and a plurality of rear rollers equally spaced on a circular edge of the rear wheel, the rear rollers being in contact with the main rollers; a plurality of coupling members for holding the front carrier, the front wheel, the rear wheel, and the rear carrier together; a plurality of outer gear assemblies each rotatably disposed in the eccentric stepped-diameter hole, the fourth through hole, the second through hole, and one of the recesses; and a central gear unit rotatably disposed through the central hole of the rear carrier, the third through hole, the first through hole, and the central through hole of the front carrier to be in gear mesh with the outer gear assemblies; wherein the numbers of the recesses, the eccentric stepped-diameter holes, the second through holes, the fourth through holes, and the outer gear assemblies are the same; and wherein a rotation of the central gear unit rotates the outer gear assemblies which in turn rotate both the front and rear wheels so as to rotate the rotation member.