1. Select the standard coupling. When choosing a coupling, designers should first choose among the couplings that have been formulated as national standards, mechanical industry standards and national patents. Only if existing standard couplings and patented couplings do not meet the design requirements, you need to design your own couplings.

2. Select the type and coupling type

Learn about the comprehensive functionality of couplings in the drivetrain, especially flexible couplings, and select the type and type of coupling from the overall design of the drivetrain. The type of coupling is selected according to a combination of factors such as the type of initial idea and type of workload, working speed, transmission accuracy, two-axis offset conditions, temperature, humidity, working environment, etc. Select the structure of the coupling according to the needs of the support host. When couplings are used with brakes, couplings with brake wheels or discs should be selected. When overload protection is required, a safety coupling should be selected; When connecting with a flange, the flange type should be selected. For long-distance transmission, when the axial size of the connection is large, it is better to choose the intermediate shaft type or intermediate sleeve type.

3. Coupling torque calculation

The power of the power machinery in the transmission system should be greater than the power required by the working machinery. According to the power and speed of the power machine, the high-speed theoretical short torque T connected to the power machine can be calculated. According to the working condition coefficient K and other correlation 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. The main choice of coupling model

Based on 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 pre-selected, and the allowable velocity [n], maximum radial size D and axial dimension L0 of the coupling can be found from the standard, and the coupling speed n≤ [n].

5. Adjust the model according to the shaft diameter

The initially selected coupling size, i.e. shaft bore diameter d and shaft bore length L, should meet the requirements of spindle end and driven end shaft diameter, otherwise the coupling specification must be adjusted according to the shaft diameter d. A common phenomenon is that the shaft diameter of the drive and driven ends is different. When the torque and speed are the same, and the shaft diameter of the drive end and the driven end are different, the coupling model should be selected according to the larger shaft diameter. In the newly designed drivetrain, the shaft hole types defined in GB/T3852 should be selected, and the J1 shaft hole type is recommended to improve versatility and interchangeability. The length of the shaft bore depends on the size of the coupling product. Sketch

6. Select the connection type

The choice of coupling connection type depends on the type of connection of the spindle and driven end to the shaft. Typically, a key connection is used, where the key connection type and code are the same. There are 3852 keyway types and 4 keyless types in GB/T7. For connections, A-type keys are more commonly used.

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

Select the type of coupling according to the load type, speed, working environment and other comprehensive factors of the power machine and coupling; Select the type of coupling according to factors such as matching and connection of the coupling; Select the specifications (models) for diameter and shaft bore length according to the rated torque and shaft bore. To ensure the strength of the axes and bonds, after selecting a coupling model (specification), the strength of the axes and bonds should be checked to finalize the coupling model.