2. Select the type and type of coupling.
Understand the comprehensive function of coupling (especially flexible coupling) in transmission system, and choose the variety and type of coupling from the overall design of transmission system. According to the type of prime mover, working load, working speed, transmission accuracy, two-axis deviation, temperature, humidity, working environment and other comprehensive factors, the variety of coupling is selected. Select the structure type of coupling according to the need of supporting the main engine. When the coupling and brake are used together, the coupling with brake wheel or brake disc should be selected. When overload protection is needed, safety 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, coupling torque calculation
The power of the power machine in the transmission system should be greater than the power required by the workpiece machine. According to the power and speed of the power machine, the theoretical short torque t of the high-speed end 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 degree t is inversely proportional to n, so the low-speed end t is greater than the high-speed end t.
4. Preliminary selection of coupling model
According to the calculated torque Tc, similar nominal torque Tn can be selected from the standard series, and Tn≥Tc should be satisfied when selecting the model. The model (specification) of the coupling is preliminarily selected, and the allowable rotational speed [n], the maximum radial dimension d and the axial dimension L0 of the coupling can be found from the standard, so that the rotational speed n of the coupling is ≤ [n].
5. Adjust the model according to the shaft diameter.
The shaft hole diameter d and the shaft hole length l initially selected should meet the requirements of the shaft diameters of the driving end and the driven end, otherwise, the specifications of the coupling should be adjusted according to the shaft diameter d, and it is common that the shaft diameters of the driving end and the driven end are different. When the torque and speed are the same and the shaft diameters of the driving and driven ends are different, the coupling model should be selected according to the large shaft diameter. In the newly designed transmission system, seven shaft hole types conforming to GB/T3852 should be selected, and J 1 shaft hole type is recommended to improve universality and interchangeability, and the length of shaft hole should meet the requirements of coupling product standard.
6. Select the connection type
The choice of coupling connection mode depends on the connection mode of the driving end and the driven end on the shaft, and the key connection is generally adopted. In order to unify the key connection types and codes, GB/T3852 stipulates 7 keyway types and 4 keyless connections, and A-type keys are widely used.
7. Select the variety, type and specification (model) of the coupling.
According to the comprehensive factors such as load category, speed and working environment of power machine and coupling, the type of coupling is selected; Select the coupling type according to the matching and connection of the coupling; Select specifications (models) according to nominal torque, shaft hole diameter and shaft hole length. In order to ensure the strength of shaft and key, after selecting the model (specification) of coupling, the strength of shaft and key should be checked to finally determine the model of coupling.