Abstract: There is disclosed a fluid driven motor of particular use, for example, in drilling apparatus or in powering underwater excavation apparatus. Known motors suffer from a number of problems, e.g. lack of sufficient hydraulic efficiency. According to one aspect of the present invention there is provided a motor comprising a stator and a rotor rotatably mounted in the stator, wherein the stator is provided with at least one rod recess formed in an inner surface thereof, the stator providing at least one inlet/exhaust port communicating between a surface of the rod recess and an outer surface of the stator, the rotor is provided with a rotor channel and at least one channel for conducting motive fluid from the rotor channel to a chamber between the rotor and the stator, and the at least one rod recess is provided with a rod which, in use, may form a seal between the stator and the rotor.

Abstract: A drilling motor has been developed with a hollow tubular stator having at least one rod recess therein and an inlet port therethrough corresponding to each of the at least one rod recess; a rod movably disposed in each of the at least one rod recess; a tubular rotor movably disposed within the stator for rotation therein, the tubular rotor having a central motive fluid flow channel therethrough and extending along the length of the rotor, the rotor having one or more radial exhaust flow channels therethrough for providing a motive fluid flow path to the central motive fluid flow channel from at least one action chamber between the hollow tubular stator and tubular rotor; the tubular rotor having at least one rotor seal; and the at least one action chamber defined by an interior surface of the hollow tubular stator and an exterior surface of the tubular rotor, each of the at least one action chamber sealed at one end by the rod and at another end by one of the at least one rotor seals.

Abstract: A drilling motor has been developed with a hollow tubular stator having at least one rod recess therein and an exhaust port therethrough corresponding to each of the at least one rod recess; a rod movably disposed in each of the at least one rod recess; a tubular rotor movably disposed within the stator for rotation therein, the tubular rotor having a central motive fluid flow channel therethrough and extending along the length of the rotor, the rotor having one or more radial flow channels therethrough for providing a motive fluid flow path from the central motive fluid flow channel to at least one action chamber between the hollow tubular stator and tubular rotor; the tubular rotor having at least one rotor seal; and the at least one action chamber defined by an interior surface of the hollow tubular stator and an exterior surface of the tubular rotor, each of the at least one action chamber sealed at one end by the rod and at another end by one of the at least one rotor seals.