534 MACHINES, WORK, AND ENERGY 



is possible to run each machine at its proper speed. The usual 

 method of distributing power from a single MOTOR (see Art. 

 651) and of regulating the speed of each machine is illustrated 

 in Fig. 334 and the following set of problems: 



PROBLEMS 



1. The gasoline engine (Fig. 334), runs at the rate of 400 r.p.m. 

 (revolutions per minute) and has a pulley 8 in. in diameter. The 

 line shaft is to have 200 r.p.m. What must be the diameter of the 

 shaft pulley? 



2. If the dynamo has a 4-in. pulley and is to run at 1200 r.p.m., 

 what must be the diameter of the line-shaft pulley which drives it? 



3. If the pulley of the feed grinder is 6 in. in diameter and the 

 line-shaft pulley which drives it is 18 in., what is the speed of the 

 grinder in r.p.m.? 



4. If the corn sheller is to have 500 r.p.m. and the line-shaft pulley 

 which drives it is 20 in. in diameter, what must be the diameter of 

 the sheller pulley? 



5. The diameter of the line-shaft pulley which drives the cream 

 separator is 18 in. The pulley on the separator is 4 in. in diameter. 

 What is the speed of the pulley in r.p.m. ? 



This pulley and the spur-wheel, No. 1, are keyed to the same shaft. 

 What is the speed of the spur-wheel? 



The spur-wheel, No. 1, has 16 cogs. These cogs mesh with the 

 cogs of an 8-cog pinion, No. 2. What is the speed of the pinion? 



The pinion, No. 2, and the spur-wheel, No. 3, are keyed to the 

 same shaft. What is the speed of the spur-wheel? 



The spur-wheel, No. 3, has 32 cogs which mesh with the cogs of 

 the 6-cog pinion, No. 4. How many r.p.m. has the pinion? 



If pinion, No. 4, has the same speed as the disks of the separator, 

 what are the r.p.m. of the disks? This is how many times the r.p.m. 

 of the line shaft? It is how many times the r.p.m. of the engine? 



6. The line-shaft pulley for driving the pump is 8 in. in diameter. 

 The pump pulley is 16 in. in diameter. How many r.p.m. has the 

 pump pulley? 



The pump pulley and pinion, No. 1, are keyed to a common shaft. 

 The pinion, No. 1 ; has 8 cogs which mesh with the 40-cog spur-wheel, 

 No. 2. The pump rod is operated by a pitman attached to the 

 spur-wheel. How many strokes per minute does the pump make? 



Is the pump gearing used to increase, or to decrease, the speed, or 

 r.p.m.? What is true of the gearing of the cream separator? 



