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### Disk Clutch Power Transmission Formula and Calculator

Power Transmitted by Disk Clutch Formula and Calculator

When designing a clutch for a given class of service, it is advisable to consider any overloads that may be encountered and base the power transmitting capacity of the clutch upon such overloads. When the load varies or is subject to frequent release or engagement, the clutch capacity should be greater than the actual amount of power transmitted. If the power is derived from a gas or gasoline engine, the horsepower rating of the clutch should be 75 or 100 percent greater than that of the engine.

The approximate amount of power that a disk clutch will transmit may be determined from the following formula,

Eq. 1
HP = µ · r · F · N · S / 63,000

Declarations

D = clutch diameter, in
R = clutch radius, mm, in
F = axial force (spring pressure) lbs
N = number of frictional surfaces
S = speed of clutch, rpm
µ = coefficient of friction
HP = horsepower frictional Horsepower

Coefficients for Clutch Calculations.

While the frictional coefficients used by designers of clutches differ somewhat and depend upon variable factors, the following values may be used in clutch calculations: For greasy leather on cast iron about 0.20 or 0.25, leather on metal that is quite oily 0.15; metal and cork on oily metal 0.32; the same on dry metal 0.35; metal on dry metal 0.15; disk clutches having lubricated surfaces 0.10.

Related:

Credits:

Machinerys Handook, 23rd edition