Rotary piston engine with contra-rotating rotors - has main rotor pitch and addendum circles coinciding and of same dia. as secondary rotor dedendum circle

摘要

The rotary piston engine with contrarotating pistons has these conventionally mounted on parallel shafts, meshing so that during rotation, they define working chambers (18) varying cyclically in volume. There are seals (23, 25) and external gearing to reduce seal loading. The main rotor (13) has coinciding addendum and pitch-circles of the same dia. as the secondary rotor (14) dedendum-circle over which it rolls. The main rotor has 3-5 recesses, the other rotor having 2-4 lobes. As well as pairs of inlet (20) and exhaust (19) ports the casing includes pressure balance ducts (21).