Abstract
Such a mechanism that the elements are bilaterally symmetrical with respect to the bisecting plane of driving and driven rotational axes is able to use as the constant velocity joint. The constant velocity joint that is composed of two straight-line-contacting elements and the frame is most elementally one. The double offset constant velocity joint and the cross groove constant velocity joint are composed of several sets of the ball and two straight-line grooves. The relative motion of the ball to each of two straight grooves and the transmission of the force between them may be simulated by the straight-line-contacting constant velocity joint.
