UNIVERSAL JOINT FOR DOWN HOLE DRILLING MOTOR

摘要

A universal joint carried by an elongate body having an axis. The universal joint has an inner race that pivots omni-directionally within an outer race and a series of first and second opposed cavities formed in the inner race and the outer race. There are a plurality of torque transfer elements, each torque transfer element having a first portion that engages a first cavity and a second portion that engages a corresponding second cavity. The first cavity is a socket that permits rotation of the first portion within the first cavity as the inner race pivots omni-directionally within the outer race and the second cavity is a track oriented in the direction of the axis of the elongate body. The second portion moves along the track as the inner race pivots omni-directionally within the outer race of the second portion along the track. The second portion has at least one drive surface that engages an inner surface of the track at more than one point along the direction of the track.