Crane Duty Helical Equipment Boxes
SELECTION PROCEDURE
Satisfactory performance of the gearbox is crane duty helical gearbox dependent upon correct selection. The selection of a gear unit is influenced by the class of duty of the crane which should be determined and specific. Single, Dual and Triple stage Horizontal equipment models type HA, HB and HC are recommended for Hoist and Long Travel drive. Three stage vertical gear devices type VC are recommended for cross travel drives of the EOT crane. Assembly arrangement must be specified while purchasing the gear units.
1. Compute the required reduction ratio.
2. Determine the horsepower required for the prime mover.
3. Make reference 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 should be selected such that the ranked HP is equal or more compared to the consumed HP.
EXAMPLE
1. Select a unit to transmit 9 HP from 720 rpm electric engine for hoist drive in a class II duty crane, the reduction 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 insight rpm of 720 in class II duty the rated HP is 9.5
· As the consumed HP is 9, the unit HB-350 will end up being 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 be suitable.
· Start to see the ratio column and in the size VC – 32Q, for insight rpm of 960 in course IV duty the rated HP is 3