Enter the shaft torque, the load mode, the shaft end diameter and the speed — the calculator finds the design torque T_p = K_p·T, picks the nearest MUVP coupling from GOST 21424-93 with a suitable bore and checks the allowed speed.
How a coupling is selected
Design torqueT_p = K_p·T ≤ T_nom, where K_p is the load-mode factor: 1.25…1.5 for belt conveyors, 1.5…2 for screw, chain and scraper conveyors, 2…3 for cranes, winches and elevators.
Diameter: the coupling is chosen by the larger diameter of the two shaft ends; the standard allows half-couplings with different bores for one nominal torque.
Speed must not exceed the allowed value for the chosen size.
Shaft load. An elastic pin-and-bush coupling loads the shaft with a radial force caused by misalignment; for the project F ≈ 50√T on the high-speed and 125√T on the low-speed shaft is taken.
Couplings join the motor shaft to the gearbox input shaft and the gearbox output shaft to the machine shaft; the latter are more often chain or torus-shell couplings.
FAQ
What is the design torque of a coupling?
The nominal shaft torque multiplied by the load-mode factor K_p. It accounts for starting and shock loads; the coupling is chosen so that T_p does not exceed the nominal torque of the standard.
How is the load-mode factor chosen?
By the driven machine: belt conveyors 1.25…1.5, screw, chain and scraper conveyors 1.5…2, cranes, winches and elevators 2…3.
By which diameter is a coupling chosen?
By the larger diameter of the two connected shaft ends. If the motor shaft is thicker than the gearbox shaft end, choose by the motor shaft.
What are the drawbacks of a MUVP coupling?
A small compensating ability: with misaligned shafts it loads the shafts and supports, and the rubber bushes wear quickly.
Do the pins and bushes need a check?
In a course project a standard coupling is checked by the design torque and the speed; the pins and bushes are checked only if the assignment requires it.