The elastic deformation of the Flexible Couplings compensates the relative displacement of the two connected shafts, which is a metal elastic element flexible coupling with good performance; In the process of mechanical transmission, the load transmitted by the transmission shaft system will often change, causing different reasons for load changes, such as unstable motor speed, unstable load of the working machine and dynamic load caused by centrifugal force due to unbalanced rotating parts in the shaft system may cause load changes. Elastic coupling can adapt to the fluctuation of load, and has the capacity of buffering and vibration reduction. The stiffness of the coupling includes radial stiffness, axial stiffness and torsional stiffness. In the work of elastic coupling, periodic load is a typical load form in mechanical transmission. Changing the natural frequency of the shafting is generally to change the moment of inertia or stiffness of the shafting, which is related to the mechanical structure. Fix the outer leg on one side of the motor of the coupling of the lifting accessories, and move the inner leg until the deviation between the motor and the pump base is zero. In order to avoid resonance, the change frequency of the periodic load should be staggered from the natural frequency of the drive shaft system. Because the change frequency of the load is related to the speed of the spindle, and the speed is a mechanical property parameter, which cannot be changed at will. Since the motor cannot move at will, after fixing one side of the motor leg, the other side should be supported by the jackscrew. The elastic coupling is easy to bend under various deviations, but it also has the same effect on the rigidity of the coupling under torsional load. If the elastic rings are of the same size, they cannot be mixed, especially if the elastic rings on the same pin need to be replaced with new ones; If the clearance between the elastic coupling and the pin hole does not meet the requirements after installation, the excircle of the elastic ring can be trimmed with a fine file to make it meet the clearance requirements and meet the use conditions.