Crane Duty Helical Gear Boxes
SELECTION PROCEDURE
Satisfactory performance of the gearbox is dependent upon correct selection. The selection of a gear unit is definitely influenced by the course of duty of the crane which should be determined and specified. 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 models 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 mandatory reduction ratio.
2. Determine the horsepower required for the prime mover.
3. Refer to the rating table, find in the ratio column and based on input rpm verify the gear box ranking horizontally for various course of duty of the crane.
4. The size should be selected in a way that 
the ranked HP is equal or more compared to the consumed HP.
EXAMPLE
1. Decide on a unit to transmit 9 HP from 720 rpm electric 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 become suitable.
· Start to see the ratio column and in the size HB-350, for input rpm of 720 in course II duty the rated HP is 9.5
· Since the consumed HP can be 9, the machine HB-350 will become suitable.
2. Decide on a unit to transmit 3 HP from 960 rpm electric motor for cross travel drive in a class IV duty crane, the decrease ratio required is 14.26.
· For cross travel drive, a vertical gearbox type VC will be suitable.
· Start to see the ratio column and in the size VC – 32Q, for input rpm of 960 in class IV duty the ranked HP is 3
This website will give you with reliable info regarding crane duty helical gearbox.