CREAMERY BUTTER MAKING 



189 



the pulley when the diameter is given ; the other is to find 

 the diameter when the speed is given. 



i. To find the speed of a driven pulley : Multiply the 

 diameter of the driver by its speed and divide the product 

 by the diameter of the driven pulley. 



A i NI SNA r -r 



X SPEED X 



Fig. 54. Belting from engine to separator. 



Example : Diameter of engine pulley, 20 inches ; speed 

 of engine, 200 revolutions per minute ; diameter of driven 

 pulley, 25 inches. 



20 X 200 -r- 25 160= No. rev. per min. of driven pulley. 



2. To find diameter of driven pulley: Multiply the 

 diameter of driver by its speed and divide the product 

 by the required speed of driven pulley. 



Example : Diameter of engine pulley, 20 inches ; speed 

 of engine, 200 revolutions per minute ; speed of driven 

 pulley, 200 revolutions per minute. 



20 X 200 -f- 200 = 20 = diameter of driven pulley. 



