Crane Duty Helical Equipment Boxes
SELECTION PROCEDURE
Satisfactory performance of the crane duty helical gearbox gearbox is dependent upon correct selection. Selecting a gear unit is usually influenced by the class of duty of the crane that ought to be determined and specific. Single, Double and Triple stage Horizontal gear systems type HA, HB and HC are recommended for Hoist and Long Travel drive. Three stage vertical equipment devices 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 mandatory reduction ratio.
2. Determine the horsepower necessary for the prime mover.
3. Make reference to the rating desk, see in the ratio column and based on input rpm examine the gear box ranking horizontally for various course 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 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 insight rpm of 720 in course II duty the rated HP is 9.5
· Since 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 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 be suitable.
· See the ratio column and in the size VC – 32Q, for input rpm of 960 in course IV duty the ranked HP is 3