Calculate the belt RPM for a motor / fan unit with a 22” Fan Sheave and a 148” belt length. The fan is running at 32.7 HZ

Question

Its a question about vibration analysis.

Answer 1

Adrian,

 

The fan sheave is a small-diameter, grooved circular fan wheel that holds the bigger belt.  The circumference of this fan wheel is given as 22".  The big belt circumference is 148". The same circumferential distance is traveled on the fan wheel as the big belt if there is no slippage due to lack of tension.

 

Thus, the small driving fan wheel has to turn many times for the big belt to rotate once.  It is merely the ratio of their circumferences = 148" big belt/22" fan belt = 6.727 rotations ratio.

 

So the RPM for the big belt = 32.7 rotations/sec for fan (1/6.727 ratio)(1/60 sec/min) = 0.081 rpm