Crane Duty Helical Gear Boxes
SELECTION PROCEDURE
Satisfactory performance of the gearbox depends upon correct selection. The selection of a gear unit is definitely influenced by the course of duty of the crane that ought to be determined and specified. Single, Double and Triple stage Horizontal gear units type HA, HB and HC are suggested 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 required 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 rating horizontally for various course of duty of the crane.
4. The size ought to 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 motor for hoist drive in a class II duty crane, the decrease ratio required is 31.50.
· For hoist drive a two stage horizontal gearbox type HB will become suitable.
· See the ratio column and in the size HB-350, for input rpm of 720 in course II duty the ranked HP is 9.5
· Since the consumed HP is definitely 9, the machine HB-350 will end up being suitable.
2. Select a unit to transmit 3 HP from 960 rpm electric 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 become 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