While most rotary engines use the principle of volume variation between a
curve and a moving
cord of fixed length, this new engine concept uses a four degrees of freedom
X, Y, .theta., .PHI. rotor,
confined inside an internal housing contour wall, and does not require a
central power shaft or
support. The invention is an assembly of four carriages supporting the ends
pivots of four
pivoting blades forming a variable-shape rotor. This rotor rolls just like a
roller bearing un the
surface of an internal housing contour wall shaped like a skating rink. During
the rotation, the
rotor pivoting blades align alternatively in a lozenge and a square
configuration. All ports are
radial in the housing and/or axial on the lateral side covers. Since the
compression and expansion
strokes start and end simultaneously, an ignition flame transfer slot is used
to maintain a
continuous combustion while four strokes are completed in every rotation. A
central power shaft
is not needed for the engine to operate, but can be added and driven by the
blades, through
mechanical coupling arms. The rotary engine incorporates few parts, does not
need a crankshaft
or a flywheel, and can be made strong enough to meet the criteria of photo-
detonation and direct
hydrogen combustion.