Coupling used to firmly connect the driving shaft and driven shaft in different mechanisms for rotation together and to transmit motion and torque. Sometimes it is also used to connect shafts with other parts (such as gears, pulleys, etc.).
It is usually composed of two halves, which are respectively connected by keys or tight fitting, fastened at the ends of the two shafts, and then connected by some means.
The coupling can also compensate the offset (including axial offset, radial offset, angular offset or comprehensive offset) between the two shafts due to manufacturing and installation failure, deformation or thermal expansion during operation, etc.;
As well as impact mitigation and vibration absorption. Coupling is the core component of mud pump and the main factor affecting working efficiency.