Rockwell Automation 150 MNL/SMC DIALOG+/APP-PROD GUIDE User Manual

Page 164

10-2

Reference

Torque and Horsepower (cont.)

Torque is merely a turning effort. In the previous illustration, it takes
one pound at the end of the one foot wrench to turn the shaft at a
steady rate. Therefore, the torque required is one pound × one foot, or
one foot-lb. If the wrench were turned twice as fast, the torque
required would remain the same, provided it is turned at a steady rate.

Horsepower, on the other hand, takes into account how fast the shaft
is turned. Turning the shaft rapidly requires more horsepower than
turning it slowly. Thus, horsepower is a measure of the rate at which
work is done. By definition, the relationship between torque and
horsepower is as follows:

In the above example, the one pound of force moves a distance of:

To produce one horsepower, the shaft would have to be turned at
rate of:

For this relationship, an equation can be derived for determining
horsepower output from speed and torque.

For this relationship, full-load torque is:

1 Horsepower

33,000 ft.-lbs./Min.

2 Ft.

1 Lb. or 6.68 ft.-lb

1 HP

33,000 ft.-lbs./Min.

6.28 ft.-lbs./Revolutio

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5,250 R

RPM

Torqu

30,00

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RPM

Torqu

5,25

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Full-load Torque in ft.-lb

5,25

Full-load RPM

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