What is the difference in performance between single universal coupling and double universal coupling?

The universal coupling can allow the two shafts to be connected to work under a relatively large deflection (<45 degrees).However, when the driving shaft of the single universal joint rotates one revolution at a constant angular velocity, although the follower also rotates one revolution, the angular velocity changes periodically in w/Cosa-w cosa, which will cause additional dynamic load and deflection during transmission. The larger the angle, the greater the angular velocity fluctuation of the driven shaft and the dynamic load caused by it.The double universal coupling can avoid this shortcoming.When the double universal coupling is connected, the fork joints at both ends of the intermediate shaft should be located in the same plane, and the angle between the intermediate shaft, the driving shaft and the driven shaft should be equal, so as to ensure the driving shaft and the driven shaft The instantaneous angular velocities are equal.