Page:The Kinematics of Machinery.djvu/425

 CHAMBER-WHEEL TRAINS. 403

A chamber-wheel train consists of a chain (R Z C^) so formed into a mechanism, by making one of its links a chamber, that it can be chained with a pressure-organ which shall enter the spaces between the teeth, pair with them, move forward with them, and finally be compelled to leave them where the two wheels gear with each other. One or both of the spur-wheels is used as the piston, while the frame C ...... G is formed into the chamber.

There are necessarily a number of solutions of this general problem. The machines thus obtained may as we have already found in the case of the crank mechanisms be used either to cause the motion of a pressure-organ (as in a pump), or as a " prime mover," receiving motion from the pressure-organ, or for other purposes. The general character of the mechanism remains always the same, the special arrangement of it adopted depending upon the particular object in view. We shall here briefly examine a few of the most important forms of chamber- wheel gear.

94.

The Pappenheim Chamber-wheels. Plate XXXII.

The spur-wheel mechanism (C z (?' 2 ') (Fig. 278), as the geometri- cally simplest case of (P n (7 2 ), furnishes our first chamber-wheel train ; the form chosen for it being that in which the wheels a and I are made equally large. The frame c becomes a chamber encircl- ing a and b, and furnished with an inlet and outlet passage upon opposite sides of the two shafts. This gives us the oldest form of chamber-wheel gear, the construction of which is shown schema- tically in Figs. 1 and 2, PL^XXII. Two similar spur-wheels, a and ft, having their teeth made so as to work without play, are enclosed in a chamber which has two semi-cylindrical wings, with which the points of the teeth remain in contact during their motion. The chamber has two openings, one on each side of the parallel shafts, and has plane end surfaces with which the ends of the

it with the present chapters it will be noticed that the general method and scope of both are very much alike, although here I can go considerably further into the matter than was formerly possible. JP. :

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