Crane Duty Helical Gear Boxes
SELECTION PROCEDURE
Satisfactory performance of the gearbox is dependent upon correct selection. The selection of a gear unit is usually influenced by the course of duty of the crane which should be determined and specific. Single, Double and Triple stage Horizontal equipment units type HA, HB and HC are suggested for Hoist and Long Travel drive. Three stage vertical equipment products type VC are recommended for cross travel drives of the EOT crane. Assembly arrangement should be specified while ordering the gear units.

1. Compute the required reduction ratio.
2. Determine the horsepower necessary for the prime mover.
3. Refer to the rating table, find in the ratio column and predicated on input rpm verify the gear box ranking horizontally for various class of duty of the crane.
4. The size should be selected in a way that the rated HP is equal or even more than the consumed HP.

EXAMPLE
1. Select a unit to transmit 9 HP from 720 rpm electric motor for hoist drive in a course II duty crane, the reduction ratio required is 31.50.
· For hoist drive a two stage horizontal gearbox type HB will end up being suitable.
· See the ratio column and in the size HB-350, for input rpm of 720 in class II duty the ranked HP is 9.5
· Because the consumed HP is 9, the unit HB-350 will become suitable.

2. Decide on a unit to transmit 3 HP from 960 rpm electric electric motor for cross travel drive in a class IV duty crane, the reduction ratio required is 14.26.
· For cross travel drive, a vertical gearbox type VC will become suitable.
· See the ratio column and in the size VC – 32Q, for input rpm of 960 in class IV duty the ranked HP is 3

You’ll locate that there are many resources available for information pertaining to crane duty helical gearbox, yet naturally they are of varying degrees of reliability.