1. Coupling function

　　It is used to connect the two shafts together. The two shafts cannot be separated when the machine is running. The two shafts can only be separated after the machine is stopped and the connection is disconnected.

　　2. Type of coupling

　　Due to manufacturing and installation errors, deformation after load, and the influence of temperature changes on the two shafts connected by the coupling, the relative position of the two shafts will change, and strict alignment is often not guaranteed.According to whether the coupling has elastic elements, whether it has the ability to compensate various relative displacements, that is, whether it can maintain the connection function and the purpose of the coupling under the condition of relative displacement, the coupling can be divided into rigid couplings, Flexible coupling and safety coupling.

　　Rigid coupling: It can only transmit motion and torque, and does not have other functions including flange coupling, sleeve coupling, clamp coupling, etc.

　　Flexible coupling: A flexible coupling without elastic elements can not only transmit motion and torque, but also has different degrees of axial, radial and angular compensation performance, including gear couplings, universal couplings Couplings, chain couplings, slider couplings, etc.

　　The flexible coupling with elastic elements can transmit motion and torque; it has different degrees of axial, radial, and angular compensation performance; it also has different degrees of damping and buffering effects to improve the working performance of the transmission system, including Various non-metal elastic element flexible couplings and metal elastic element flexible couplings have different structures and differences, and their roles in the transmission system are also different.

　　Safety coupling: transfer movement and torque, overload safety protection.Flexible safety couplings also have different degrees of compensation performance, including pin type, friction type, magnetic powder type, centrifugal type, hydraulic type and other safety couplings.