Rotary internal combustion engine

In a rotary internal combustion engine of the type which includes a fixed engine frame, a block rotatable about a block axis, an output shaft rotatable about a shaft axis, said shaft axis being offset from said block axis to define an eccentricity, at least one cylinder means including a cylinder housing, a piston and a drive rod, said piston having an edge surface slidably engaging said cylinder housing, said drive rod being connected to said piston, said cylinder means having a cycle including a power stroke, means for supplying a combustible mixture to said cylinder means, and ignition means for igniting said combustible mixture in said cylinder means, an improved means for driving said output shaft comprising, in combination:

• a housing within said block and rotatable about said one block axis, said housing having at least a pair of opposing walls and substantially enclosing said output shaft, said housing defining a lubricant reservoir for said rotary engine;
• a key member rigidly secured to said output shaft;
• a yoke member slidably engaging said opposing walls of said housing, said key member slidably engaging said yoke member, said yoke member being rotatable substantially about said shaft axis;
• and
• means for connecting said drive rod and said yoke member to define a connection point, said connection point being radially offset from said block axis throughout said cycle of said cylinder means;
• said housing, yoke member, key member, connecting means and eccentricity cooperatively defining variable moment arm means for rotating said block and output shaft in response to said cylinder means, said variable moment arm means having a predetermined length at initiation of said power stroke and a maximum length during said power stroke.