Coupling function is used to connect two shafts together. The two shafts cannot be separated when the machine is running. The two shafts can be separated only after the machine is stopped and the connection is disconnected.Coupling type The two shafts connected by the coupling will change the relative position of the two shafts due to manufacturing and installation errors, deformation after loading, and the influence of temperature changes. 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.The main types, characteristics and functions of the coupling and its role in the transmission system. Remarks: Rigid couplings can only transmit motion and torque, and do not have other functions including flange couplings, sleeve couplings, and clamps. Flexible couplings such as shell couplings and flexible couplings without elastic elements can not only transmit motion and torque, but also have different degrees of axial, radial and angular compensation performance, including gear couplings, Flexible couplings with elastic elements such as universal couplings, chain couplings, slider couplings, etc., can transmit motion and torque; have different degrees of axial, radial, and angular compensation performance; and It has different degrees of damping and buffering effects, and improves the working performance of the transmission system. It includes various non-metal elastic element flexible couplings and metal elastic element flexible couplings. The structure of various elastic couplings is different, and the difference is relatively large. Large, the role in the transmission system is also different. The safety coupling transmits motion and torque, and protects against overload safety.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