Rotating Horsepower

 Rotation horsepower, abbreviated as \(HP_r\), is converting the objects horsepower into rotational motion.

 

Rotating Horsepower formula
\(\large{ HP_r = \frac{ \tau \; s }{ 5252 } }\)
Symbol	English	Metric
\(\large{ HP_r }\) = rotating horsepower	\(\large{\frac{lbf-ft}{sec}}\)	\(\large{\frac{Btu}{s}}\)
\(\large{s}\) = rotation shaft speed, RPM	\(\large{\frac{ft}{sec}}\)	\(\large{\frac{m}{s}}\)
\(\large{ \tau }\)  (Greek symbol tau) = torque	\(\large{lbf-ft}\)	\( N-m \)

• \(\large{ 1 \; HP  =  5252\; RPM }\)   When charting torque and horsepower, the math always cross at 5252 RPM.

 

Rotating Horsepower formula
\(\large{ RHP =  \tau \; \frac{ s }{ 33,000 } \; 2 \; \pi }\)
Symbol	English	Metric
\(\large{ HP_r }\) = rotating horsepower	\(\large{\frac{lbf-ft}{sec}}\)	\(\large{\frac{Btu}{s}}\)
\(\large{ \pi }\) = Pi	\(\large{3.141 592 653 ...}\)
\(\large{s}\) = rotational shaft speed, RPM	\(\large{\frac{ft}{sec}}\)	\(\large{\frac{m}{s}}\)
\(\large{ \tau }\)  (Greek symbol tau) = torque	\(\large{lbf-ft}\)	\( N-m \)

• \(\large{ 1 \; HP  =  33,000 \; \frac{lbm-ft}{min}  }\)