DIFFERENTIAL DEVICE AND METHOD OF MANUFACTURING THE DEVICE

摘要

A differential device, comprising (a) a casing having an opening part in both side walls, (b) a pair of disk plates which are stored rotatably and opposedly to each other in the casing, of which connection part with a shaft is supported on each opening part of the casing, and which are formed in the opposed surfaces thereof with a continuous meandering groove varying in radial position, (c) a plurality of balls rolling in the meandering groove, and (d) a ball holder which is positioned between the disk plates, locked to the casing, and in which a plurality of slender guide holes for holding the balls one by one are formed in the radial direction, characterized in that the meandering groove has a first district extending from a radial outer side to a radial inner side and a second district extending from a radial inner side to a radial outer side, and an inflection district which connects the first district to the second district is made larger in width and/or depth dimension than the first and second districts so as to reduce a stress of contact between the balls and the meandering groove.