Angular Transmission 4R Mechanism 2

Two spherical 4R mechanisms are connected back to back. 4R: 4 revolute joints. In each mechanism the center lines of 4 revolute joints intersect at a common point. The angle between center lines of revolute joints for the orange link is not 90 deg. (rather than Cardan joints). Angle between the input and output is A = 90 deg. Angle between cylinder of the orange link and the input shaft is B = A/2 = 45 deg. This condition makes the mechanism a constant-velocity joint. The orange link rotates without f