Patent ID: 8777759

Claim:
A universal joint comprising: a cross shaft member including first, second, third and fourth shaft parts forming a cross-shape; and first, second, third and fourth bearing cups corresponding respectively to the first, second, third and fourth shaft parts, wherein each bearing cup has a hollow-cylindrical shape having a bottom and is rotatably mounted to the corresponding shaft part through a roller disposed between an inner peripheral surface of the each bearing cup and an outer peripheral surface of the corresponding shaft part, wherein each bearing cup includes an inner bottom surface in sliding contact with a distal end surface of the corresponding shaft part, wherein the sliding contact is in an annular region encompassing a central axis of the corresponding shaft part; wherein the distal end surface of the first shaft part is formed with at least one annular groove encompassing the central axis of the first shaft part for storing oil, wherein the at least one annular groove is located within the annular region, wherein each shaft part is formed with an oil hole inside thereof, wherein the oil hole has an opening at the distal end surface of each shaft part, and each bearing cup has a recess at the inner bottom surface, and wherein the recess faces the oil hole of the corresponding shaft part and defines a space configured to hold oil.