Hooke joint is the type of joint used to transmit velocity between two co-planar shafts. However an important feature of the joint is that it can transmit velocity even if there is some misalignment of few degrees.
There are many types of Hooke joints but the most common one is the Cardan-type or Hooke’s joint. Normally the joint comprises of three parts – two forks and a central block.
When we are using Hooke’s joint alone in the assembly, if gives us nonuniform motion. So it means that if the driving shaft revolves with constant angular velocity then Hooke’s joint will transmit angular velocity with some fluctuations. The level of these fluctuations depend upon the misalignment between two shafts.
Sometimes we use two Hooke’s joint on the same shaft where one joint is used at the transmission and the second one is used at the rear axle. However if both joints are installed at the same angle, then it will transmit uniform velocity to the wheels.