Page:The Kinematics of Machinery.djvu/475

 FLYWHEELS.

453

Toothed-wheels, Chain-wheels.

Toothed wheels are links of the chain (R t C') t of which an ex- ample is furnished by the spur-train of Fig. 316. The framing carrying the plummer-blocks takes the place ( 112) of the straight

FIG. 31<>.

FIG. 317.

link c. If a toothed wheel be geared with a chain we obtain the pair R 7, T (Fig. 323). A suitable combination of such pairs gives us chain- wheel gearing.

116. Fly-wheels.

We have already had an opportunity ( 45) of examining the kinematic meaning of fly-wheels. They are heavy bodies formed as revolutes, and attached to links of the form C + ... \ ... C + in order either to carry the machine over its dead points by their momen- tum, or to make its motion more uniform. They do not demand any special symbolic indication as links or elements, for our nota- tion is not concerned with the masses of the parts it represents.