STEEL BALL ROLLING STRUCTURE AND CONSTANT VELOCITY UNIVERSAL JOINT

摘要

The present invention provides a steel ball rolling configuration and a constant velocity universal joint that achieve a superior oil retention effect between a surface of a steel ball and a partner rolling surface, can form a thick oil film, improve lubrication, and extend life of the steel ball. The constant velocity universal joint of the present invention includes a rolling surface and a steel ball 7 that is lubricated by grease and rolls over the rolling surface. A surface roughness of the steel ball 7 is roughened to become more similar to a surface roughness of a partner rolling surface. Numerous miniscule recesses 15 roughly tens of micrometers in size are randomly disposed on the surface of the steel ball 7.