The following factors need to be considered when choosing a coupling:

1. The torque to be transferred and its properties, as well as the requirements for the buffering and vibration reduction function. For example, for high-power heavy-duty transmission, can choose the gear coupling; For the transmission with severe impact load or the need to eliminate torsional vibration of shafting, the wheel coupling and other coupling with high elasticity can be selected.

2. The working speed of the coupling and the magnitude of the centrifugal force caused. For high-speed transmission shafts, couplings with high balance accuracy, such as diaphragm couplings, should be selected, and should not be selected with eccentric sliding block couplings.

Coupling is used in a variety of different host products, the surrounding working environment is relatively complex, such as temperature, humidity, water, steam, dust, sand, oil, acid, alkali, corrosive medium, salt water, radiation, etc., is one of the important factors to be considered when choosing the coupling. For high temperature, low temperature, with oil, acid, alkali medium working quality, it is not appropriate to choose the general rubber as the elastic element material of the flexible coupling, should choose metal elastic element flexible coupling, such as the diaphragm coupling, such as spring coupling snake.

3. Magnitude and direction of the relative displacement of the two axes. Flexible couplings should be used when it is difficult to keep the two shafts in strict alignment after installation and adjustment, or when the two shafts will have a large additional relative displacement in the working process. For example, when the radial displacement is large, the slider coupling can be optional, and the universal coupling can be used for the connection with the larger angular displacement or intersecting two axes.

4. Reliability and working environment of coupling. Non-lubricated couplings, usually made of metal elements, are more reliable; The performance of coupling requiring lubrication is easily affected by the degree of lubrication perfection and may pollute the environment. Coupling containing rubber and other non-metallic components is sensitive to temperature, corrosive medium and strong light, and easy to age.

5. Manufacture, installation, maintenance and cost of couplings. On the premise of satisfying the performance of convenient use, couplings with convenient installation and disassembly, simple maintenance and low cost should be selected. For example, the rigid coupling is not only simple in structure, but also easy to assemble and disassemble, and can be used for low speed, rigid transmission shaft. General non-metallic elastic element couplings (such as elastic cylindrical pin couplings, elastic cylindrical pin couplings, quin-shaped elastic couplings, etc.) are widely used for general medium and low power transmission due to their good comprehensive capacity.