Trochoidal rotary piston machine with piston follow-up mechanism

A rotary piston machine of trochoidal construction comprising a rotatable drive shaft having an eccentric portion and supported for rotation in two spaced bearings, a piston eccentrically mounted on the eccentric portion of the drive shaft for contra rotation relative thereto in a housing, the piston being of epitrochoidal type with 1:1 generating circles and defined with an outer envelope and the housing having a co-operating working surface for the piston which substantially conforms to the outer envelope of the epitrochoid, and a piston follow-up mechanism comprising a pair of relatively offset eccenters mounted for eccentric rotation about the eccentric portion of the drive shaft with the piston, said eccenters being rotatably mounted in respective guide members which are constrained by respective guiding means to reciprocate rectilinearly along angularly offset paths with rotation of the piston, the pair of offset paths with rotation of the piston, the pair of eccenters being located immediately adjacent the piston and secured for rotation directly therewith whereby to reduce the length of the eccentric portion of the drive shaft, and wherein the machine housing comprises one module within which the piston rotates and defining the cooperating working surface and another module within which a first of the eccenters rotates and the respective guide member and guiding means are disposed, said another module defining an axial end wall of a working volume of the housing within which the piston rotates.