Crane gearbox applications
Where LT, HC and HD crane duty gearboxes are used, and how to select the right size for a hoist or travel drive.
EOT crane main hoist
The main hoist drum is driven directly by the output shaft or through a standard gear ring. Typical hoisting ratios start at 25:1 on the HC series and go to 560:1 on the HD series for slow lifting speeds. Check the drum load against the permissible overhung load of the size.
Auxiliary hoist
High ratios with modest power: the four-stage HD series with primary reduction gives controlled, slow lifting from 140:1 to 560:1.
Long travel and cross travel
Bridge and trolley travel drives run at lower ratios. The two-stage LT series covers 6:1 to 26:1, and the HC series takes over from 25:1.
Winches, gantry and goliath cranes
Rope winches and outdoor cranes use the same crane duty construction, with fabricated steel housings for the largest sizes.
How to select a crane gearbox
Find the ratio
i = motor rpm ÷ drum rpm. Use 1440 rpm for a 4-pole and 960 rpm for a 6-pole motor.Set the service factor
Take the service factor from your crane's duty class. If you are unsure, send us the duty and we confirm it.
Pick the size
The rating at your motor speed and nominal ratio must be at least
motor kW × SF. The quick selector does this for you.Check the torque
Input torque = kW × 9550 ÷ rpm,Rated output = input × i × 0.98,Max = rated × SF.Check the drum mounting
Compare the drum load with the permissible overhung load of the size, or choose the standard gear ring arrangement.
Need a price or a certified GA drawing?
Send us your motor power, speed and ratio.