What does a constant velocity joint do?
Here’s an example. In a front wheel drive, the wheels have to turn to steer, and move up and down as part of the suspension. But the wheels are driven by the transaxle in the front of the car, which is fixed. The power cannot be transferred out in a “straight line” to the wheel, but must travel through something that can “bend” as the wheel turns, but does not slip. The constant velocity joint on the axle will do that.
