296 CREAMERY BUTTER MAKING 



the pulley when the diameter is g-iven ; the other is to find 

 the diameter when the speed is g^iven. 



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. 



....eo »,.t = o X sfcto X 



•ooe *«cv. 



Fig. 85.— 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-^ 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 ^ 200 = 20 — diameter of driven pulley. 



