Abstract: A coupling for use between two rotating shafts in a high-temperature, high-vacuum environment is described. The coupling includes a socket having two closed loop, axially spaced, interior bearing surfaces and a roller having two closed loop, axially spaced, exterior bearing surfaces for rolling contact with the interior bearing surfaces of the socket. The interior and exterior bearing surfaces make rolling contact at two radially opposed and axially spaced locations, and the second shaft is disposed at a desired angle with respect to the first shaft. Means are provided for preventing disengagement of the roller and shaft as they rotate. In a preferred embodiment, the angle between the shafts is constant as they rotate and the roller is sized so that it is easily removed from the socket when the axes of the shafts are approximately aligned.