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

1. Compute the required reduction ratio.
2. Determine the horsepower required for the prime mover.
3. Refer to the rating desk, see in the ratio column and based on input rpm verify the gear box rating horizontally for various class of duty of the crane.
4. The size ought to be crane duty helical gearbox selected such that the ranked HP is equal or even more compared to the consumed HP.

EXAMPLE
1. Decide on a unit to transmit 9 HP from 720 rpm electric motor 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 be suitable.
· See the ratio column and in the size HB-350, for insight rpm of 720 in class II duty the ranked HP is 9.5
· As the consumed HP is definitely 9, the unit HB-350 will be suitable.

2. Decide on a unit to transmit 3 HP from 960 rpm electric engine for cross travel drive in a course IV duty crane, the reduction ratio required is 14.26.
· For cross travel drive, a vertical gearbox type VC will end up being suitable.
· Start to see the ratio column and in the size VC – 32Q, for insight rpm of 960 in class IV duty the ranked HP is 3