Gearbox Selection for Horizontal Units
Select Gearbox Type
Parallel Shafts (helical) or right angle drive
(bevel/helical), foot mount, shaft mount with or without foot.
Calculate gearbox ratio = Input Speed/ Output speed
Select Gearbox Size from Mechanical Capacity
Determine type of load from table uniform, moderate shock or
Determine mechanical service factor from table 1
Calculate the required mechanical power capacity (Pm )
(Pm ) = absorbed power (kW) x mechanical service factor
Select gearbox size from rating tables.
Pm must be equal to or less than the mechanical rating of the
Thermal Rating Check
3.1 Thermal ratings are given for the following four cases :
Gearbox without additional cooling.
Gearbox fitted with fan.
Gearbox fitted with cooling water coil.
Gearbox fitted with fan and coil.
Determine the thermal service factor from table 2
Calculate the required thermal power capacity (Pt)
(Pt ) = absorbed power (kW) ÷ thermal service factor.
Specify the type of cooling required by referring to thermal
must be equal to or less than the thermal capacity of the
Additional Catalogue Information
Gearbox overload capacity at start.
2.5 x mechanical rating, 5 times per day or,
2 x mechanical rating, 5 times per hour.
Higher power than catalogue mechanical ratings can be
transmitted on very intermittent operation within the finite
life of the gears. Consult us with specific application