Since the transmitted speed of a single cross coupling fluctuates sinusoidally, it is rarely used.Generally, two cross couplings are used in series, and the two waveforms are superimposed to transmit the speed and torque uniformly.I am a car maker, so I will use car parts as an example.The steering gear of the car and the drive shaft of the rear drive vehicle (the front drive vehicle does not use this, its drive shaft is a ball and cage type constant velocity universal joint).The former is to transfer the steering wheel angle to the steering mechanism through the steering column and coupling.The latter transfers the engine torque through the gearbox and clutch to the differential on the rear axle to drive the wheels through the coupling. (Look for a truck, you can see it when you climb down).
