Compressor, engine or pump with a piston translating along a circular path

A device comprising:

• a chamber wall comprising an outer surface and an inner surface, wherein the inner surface encloses a lobed chamber with a plurality of lobes and the inner surface comprises segments of arcuate surfaces, each of the segments of arcuate surfaces being tangent with its immediate neighboring segments, and wherein the chamber wall further comprises channels connecting the outer surface and the inner surface of the chamber wall, channels through an end surface of the chamber wall, or both the channels connecting the outer surface and the inner surface of the chamber wall and the channels through the end surface of the chamber wall;
• and
• a piston configured to translate along a circular path relative to the chamber wall and form enclosed spaces between the piston and the chamber wall;
• wherein the piston does not rotate relative to the chamber wall during translation;
• wherein the piston comprises an outer surface enclosing a main body of the piston, the main body having a plurality of lobes located in the lobes of the lobed chamber, the outer surface of the piston and the inner surface of the chamber wall engaged during translation and forming a fluid-tight seal between some portions of the outer surface of the piston and the inner surface of the chamber wall;
• wherein the device further comprises a seal plate attached to an end of the main body;
• wherein the seal plate forms a fluid-tight seal with the chamber wall;
• wherein the seal plate comprises through holes between two opposing surfaces, and the through holes are configured to be fluidly connected to the enclosed spaces.