Rotary Engine 101: The Cycle
Observe, below, the cycle of a rotary engine. Run your mouse over each image to see additional info. Notice that each of the four strokes is represented by a side of the square and that Top Dead Center (TDC) and Bottom Dead Center (BDC), the minimum and maximum chamber volumes, are at the corners. The rotor is rotating at one third the forward rate of the eccentric shaft and it takes 270 degrees of eccentric shaft rotation between TDC and BDC, and vice versa, which is 90 degrees longer than the 180 degree stroke of a conventional piston engine.
While we are concentrating on only one working chamber, for the sake of clarity, please note that each chamber is performing its own cycle, 120 degrees out of phase with its neighbor. In this way, the three chambers contribute to the production of one power stroke per rotor per revolution of the eccentric shaft, which yields twice the capacity of a piston engine of identical rated displacement.
Copyright © 2001 by Blake Qualley. All Rights Reserved.