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

1. Compute the mandatory reduction ratio.
2. Determine the horsepower necessary for the prime mover.
3. Refer to the rating desk, observe in the ratio column and predicated on input rpm check the gear box ranking horizontally for various crane duty helical gearbox course of duty of the crane.
4. The size ought to be selected in a way that the rated HP is equal or more than the consumed HP.

EXAMPLE
1. Select a unit to transmit 9 HP from 720 rpm electric engine for hoist drive in a course II duty crane, the decrease ratio required is 31.50.
· For hoist drive a two stage horizontal gearbox type HB will end up being suitable.
· Start to see the ratio column and in the size HB-350, for input rpm of 720 in course II duty the ranked HP is 9.5
· Since the consumed HP is certainly 9, the unit HB-350 will be suitable.

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