Torque Calculation: Use these formulas and the appropriate safety factor to determine the correct clutch size for any application. Clutch size requirement should be determined based on peak torque capability of the engine.
RPM
Safety Factor
Duty Classification Selection Guide
Extra Light Duty
Pumps - Centrifugal
Hydraulic Pumps
w/o priming
Irrigation Pumps
Light Duty
Cereal Dryers
Elevators - Bucket
Machines, general - all types with uniform loads,
non reversing
Medium Duty
Agitators - solid or semi solids
Blowers & fans
centrifugal & lobe.
Compressors - all
centrifugal, screw
Elevators - bucket, non-uniformly loaded or fed
Mixers - continuous
Pumps - two or more
cylinders
conveyors - uniformly loaded
Dredge Pumps
(allow for shock loading)
Heavy Duty
Cranes & Hoist
- working clutch
Crushers - ore & stone
Chipper - wood
Drums - barking
Compressors - lobe rotary plus three or more cylinder reciprocal type.
Machines - impact load types
Mills - ball type
Mud pumps
Allowable Side Load
Allowable side-pull loads for PTO's. The following formula should be used for determining the allowable side load "L" (lbs.).
L = 126,000 x HP x FL
N x D
L = Allowable side load (lbs.) N = Shaft speed (RPM) D = Pitch dia. of pulley, chain or gear (inches) FL = Load factor 1.0 for single chain or gear 1.25 for double chain 1.5 for V-belt drive 2.0 for single ply belt 2.5 for double ply belt 3.0 for triple ply belt
Important: A support plate for double and triple 14" PTO's is required in side pull applications and is recommended for inline applications.