Peristaltic down-hole drilling motor

Peristaltic motor comprising motor parts including a stator suitable to be operatively coupled to the lower end of a drill string and a rotor suitable to be operatively coupled to a drill bit, said motor parts being rotatable relative to each other about a central axis, one of said motor parts comprising a co-axial tubular section and a membrane being secured to said section in such a manner that therebetween a series of breathing working chambers are created, the other of said motor parts comprising a carrier body having grooves therein and a plurality of rollers contacting the membrane at regular intervals with said tubular section, wherein the rollers are rotatably supported in said grooves of the carrier body such that each roller is rotatable relative to said carrier body about an axis of rotation being substantially parallel to the central axis of the motor, wherein the carrier body and the membrane are positioned in a manner such that a space is defined between said elements, and said space is filled with a lubricant, wherein each breathing working chamber comprises circumferentially spaced inlet and exhaust ports, and wherein the membrane extends in axial direction between a pair of circular terminal beads, the inlet ports extending along one of said beads over substantially the entire widths of the working chambers, the exhaust ports extending along the other bead over substantially the entire widths of the working chambers.