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

1. Compute the required reduction ratio.
2. Determine the horsepower necessary for the prime mover.
3. Make reference to the rating desk, discover in the ratio column and predicated on input rpm check the gear box ranking horizontally for various course of duty of the crane.
4. The size should be selected such 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 decrease 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 be suitable.

2. Decide on a unit to transmit 3 HP from 960 rpm electric engine 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 end up being suitable.
· See the ratio column and in the size VC – 32Q, for input rpm of 960 in course IV duty the rated HP is 3