1. Use standard couplings.When choosing a coupling, the designer should first choose from the couplings that have been formulated as standards, mechanical industry standards, and patents. Only when the existing standard couplings and patented couplings cannot meet the design needs, do they need to do it themselves Design the coupling.

　　2. Select the type and type of coupling

　　Understand the comprehensive function of the coupling (especially the flexible coupling) in the transmission system, and choose the type and type of the coupling from the overall design of the transmission system.According to the type of prime mover and the type of working load, working speed, transmission accuracy, two-axis offset conditions, temperature, humidity, working environment and other comprehensive factors to select the type of coupling.Select the structure of the coupling according to the needs of the supporting host. When the coupling is used in conjunction with the brake, a coupling with a brake wheel or a brake disc should be selected; when overload protection is required, the coupling should be selected; When connecting with flanges, the flange type should be selected; for long-distance transmission, when the axial size of the connection is large, the intermediate shaft type or the intermediate sleeve type should be selected.

　　3. Calculation of coupling torque

　　The power of the power machine in the transmission system should be greater than the power required by the work machine.According to the power and speed of the power machine, the high-speed theoretical short moment T connected to the power machine can be calculated; according to the working condition coefficient K and other related coefficients, the calculated torque Tc of the coupling can be calculated.The coupling T is inversely proportional to n, so the low-speed end T is greater than the high-speed end T.

　　4. Primary selection of coupling model

　　According to the calculated torque Tc, an approximate nominal torque Tn can be selected from the standard series, and the selection should satisfy Tn≥Tc.The coupling model (specification) is preliminarily selected, and the allowable speed of the coupling [n], the large radial dimension D, and the axial dimension L0 can be found from the standard, which meets the coupling speed n≤[n].

　　5. Adjust the model according to the shaft diameter

　　The initially selected coupling size, that is, the diameter of the shaft hole d and the length of the shaft hole L, should meet the requirements of the shaft diameter of the driving and driven ends, otherwise the coupling specifications must be adjusted according to the shaft diameter d.It is a common phenomenon that the shaft diameters of the main and driven ends are different. When the torque and speed are the same, and the shaft diameters of the main and driven ends are different, the coupling model should be selected according to the larger shaft diameter.In the newly designed transmission system, the seven shaft hole types specified in GB/T3852 should be selected, and the J1 shaft hole type is recommended to improve versatility and interchangeability. The shaft hole length is in accordance with the coupling product standard. .

　　6. Choose the connection type

　　The choice of coupling connection type depends on the connection type of the main and driven ends to the shaft. Generally, a key connection is adopted, which is the same key connection type and code. In GB/T3852, there are seven keyway types and four keyless connections. , The most used is the A-type key.

　　7. Select the type, type and specification (model) of the coupling

　　According to the comprehensive factors such as power machine and coupling load, speed, working environment, etc., select the type of coupling; select the coupling type according to the matching and connection conditions of the coupling; according to the nominal torque and shaft hole Select specifications (models) for diameter and shaft hole length.In order to ensure the strength of the shaft and key, after the coupling model (specification) is selected, the strength of the shaft and key should be checked, and the coupling model should be determined later.