Rotary piston internal combustion engines

Claim 1

A rotary piston engine comprising: a housing having n lobes, a shaft extending axially of said housing, an eccentric provided on said shaft, a piston having (n+1) sides and rotatable in planetary fashion within said housing about said eccentric, injection means for injecting fuel into said housing, inlet port means and outlet port means respectively admitting and exhausting working fluid from said housing, a combustion chamber formed in each of the sides of said piston, each said combustion chamber being in the form of a recess having a sidewall surrounding a base wall and having a substantially oval shape in plan view with a major axis transverse to a plane through an axis of said piston and a minor axis, each said combustion chamber lying substantially in the leading half of the side of said piston, at least one channel extending across at least a part of the trailing half of each side of said piston in a direction parallel to the plane of the side of the pistoN and opening into the combustion chamber thereon, said sidewall of each said recess including means shaped to impart a rotary motion to working fluid in said recess in a plane substantially parallel to the base wall of the recess, and said base wall of each said recess comprising at least one step therein increasing the depth of said recess toward the leading half of the side of said piston.