Crane Duty Helical Equipment Boxes
Satisfactory performance of the gearbox depends 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 equipment units type HA, HB and HC are suggested for Hoist and Long Travel drive. Three stage vertical gear devices type VC are suggested for cross travel drives of the EOT crane. Assembly arrangement must be specified while buying the gear units.
1. Compute the required reduction ratio.
2. Determine the horsepower necessary for the prime mover.
3. Make reference to the rating table, find in the ratio column and predicated on input rpm crane duty helical gearbox verify 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 ranked HP is equal or more than the consumed HP.
1. Decide on a unit to transmit 9 HP from 720 rpm electric engine for hoist drive in a course II duty crane, the reduction ratio required is 31.50.
· For hoist drive a two stage horizontal gearbox type HB will be suitable.
· Start to 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
· As the consumed HP is 9, the machine 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 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 rated HP is 3