抄録
Double offset and cross groove constant velocity joints transmit uniform rotational motion and a torque from the input shaft to the output shaft throughballs which are retained between two straight grooves of outer and inner races. In the paper, by using inclination angles between two planes perpendicular to center lines of grooves of outer and inner races, the essential condition that two straight grooves retain the ball is obtained such a condition that two points of contact between the ball and sides of the inner-race groove exist mutually the opposite side of the plane which is perpendicular to the center line of the outer-race groove and passes through the center of the ball. The condition is expressed by the inequality with respect to the twist angle of center lines of grooves and the angle between input and output shafts (the joint angle).
