THE TRACTION GEARING 



123 



belief, however, it is only necessary to observe the gearing 

 on engines which have been run by men of this opinion. 

 In many cases, the gearing will be found more badly worn 

 than its use would warrant. Engines for use in plowing 

 or road work are sometimes provided with means for keep- 

 ing a continuous flow of oil to the gears all the time the en- 

 gine is moving. This is an excellent way to lubricate 

 them and it greatly prolongs their wear. 



The Friction Clutch. The friction clutch is used to 

 connect the engine to the traction gearing and wheels. 

 By means of it, the engine may be made to travel as slowly 

 as desired, while the engine proper is running at full 

 speed. A general view 

 of the Case clutch is 

 shown in Fig. 38, with 

 the names of the various 

 parts thereon. An en- 

 larged view of the hub 

 portion is shown in Fig. 

 39. When the clutch 

 is in partial engage- 

 ment, the shoes (Fig. 

 38) press lightly against 

 the rim of the fly-wheel, 

 transmitting only part 

 of its motion to the 

 gearing. But when in 



FIG. 38. FRICTION CLUTCH. 



