Rotary mechanism with a continuous curve at the chamber waist

Abstract

An improved rotary mechanism including a housing having a chamber with a wall of a predetermined geometric shape including at least one lobe, the lobe being defined by a continuous curve, a shaft journalled in the housing and having an eccentric within the chamber, a rotor journalled on the eccentric for rotation and translation within the chamber, the rotor having plural apexes, each being provided with an apex seal receiving groove, the wall of the housing deviating from the predetermined geometric shape by being spaced outwardly from the envelope of the predetermined geometric shape and by being generally spaced inwardly from the envelope of a closed geometric figure spaced outwardly of and parallel to the predetermined geometric shape. The closed geometric shape has sharp transition points at the lobes and the wall at the lobes is defined by a continuous curve substantially encompassing the sharp transition points and extending to both sides thereof. Apex seals are disposed within the grooves and have arcuate crowns sealingly engaging the wall. The crowns are relieved on both sides of the midpoints thereof from the theoretical shape required to ensure good sealing engagement with a wall configured in the form of the closed geometric figure with minimal movement within the grooves. Thus, the seals can be wider than in conventional rotary mechanisms and provide a greater area of contact with the wall to decrease the wear rate.

Dependencies are inferred from the claim text.