Rand cam engine
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The RadMax engine, also known as Ram-cam or Rand-cam engine is a pistonless rotary engine.
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[edit] Design
The engine has a cylindrical housing, and the interior surface of either end of the housing forms a sinusoidal cam, such that the displacement along the engine's axis of any point on the interior surface varies sinusoidally as sin(2θ), each cam having two 'peaks' and two 'valleys'. The two cams at either end are offset by π / 2 with respect to each other, such that the peaks of one end line up with the troughs of the other end and the interior of the engine between the two cams has constant length along the axis of the engine at all points.
Between these two sinusoidal surfaces, a cylindrical rotor occupies almost all the cylindrical space between the two cams, and holds a series of vanes, 12 in current designs, dividing the interior space into 12 segments. The vanes make contact with both cams at either end of the housing, and move freely up and down these sinusoidal tracks through slots in the rotor.
The spaces between the rotor and each cam, and between the vanes, form combustion chambers whose volume varies in an approximately sinusoidal manner as they are swept around the engine, and into the cams at either end are inlaid induction, exhaust and fuel injection ports at appropriate points around the cycle, so each of the 24 rotating combustion chambers goes through a complete 4-stroke combustion cycle as it rotates.
This engine was invented by the Canadian inventor James McCann.
[edit] Advantages
The advantage of the rand-cam engine is its compactness and power output. Whereas a 4-cycle piston engine's piston only fires once every other turn of the crankshaft, and a Wankel engine fires once every turn of the e-shaft, a Rand-cam engine fires 24 times per revolution of its main shaft. It can also achieve high compression ratios for diesel operation.
[edit] Current status
The engine is currently under development by the US based company Regi U.S., Inc and has reportedly reached the prototype stage. According to their published information, the prototype will deliver 42 bhp from a unit only 6 inches wide by 6 inches long[citation needed] and can run on Ethanol, Natural Gas, Diesel, LPG (Propane) and Hydrogen. There are immediate plans to demonstrate the engine. The first intended users are military contractors.
