Patent ID: 7051610
Filing Date: 2006-05-30
Classification: F16H,Y10T

Abstract:
1. A ball-worm transmission assembly comprising: a worm; a plurality of spherical balls; and a gear coupled to the worm via the plurality of spherical balls; wherein the gear comprises a plurality of teeth each having a thickness in a central plane of the gear and a lesser thickness towards both sides of the gear, so that a gap is defined between the teeth which is larger towards both sides of the gear than in the central plane of the gear; and wherein a ball path of the spherical balls comprises: (i) an active path along which the balls roll between the worm and the teeth of the gear so as to engage the gear and the worm: (ii) a passive path along which the balls roll on the worm outside the teeth of the gear; and (iii) a ball recirculation along which the balls pass through the worm; wherein the gap, between the teeth of the gear is defined to correspond to the space swept by the balls on the active path rolling between the worm and the gear during a full engagement cycle of the worm and the gear, so as to allow passage of the balls on the active path with a minimized amount of backlash.