Pressure fluid motor

A pressure fluid motor comprising a housing of circular cross-section having a smooth, non-channeled, right-cylindrical, inner surface;

• a rotor concentric with said housing and having a roughened, non-channeled, right-cylindrical, outer surface, said rotor and said housing being complementary in shape and having a relatively-small, uniform clearance throughout the axial extent of said rotor and said housing;
• a jet orifice for introducing a pressure fluid jet into the space between said housing and said rotor;
• and, outlet means for venting spent pressure fluid, said jet orifice having its outermost surface tangential to the smooth, non-channeled, right-cylindrical, inner surface of said housing and a diameter greater than the clearance between said housing and said rotor, whereby a portion of said jet is jetted directly and tangentially into the space between said rotor and said housing and the balance of the jet impinges on the roughened, non-channeled, right-cylindrical surface of said rotor and is deflected by said rotor into the space between said rotor and said housing so that the jet, which initially has a diameter larger than the spacing between said housing and said rotor, is flattened to a thickness corresponding to the spacing between said housing and said rotor and fans out over the smooth, unchanneled, right-cylindrical, inner surfaces of said housing and said rotor in a free, unchanneled, fan-shaped stream, the clearance between said housing and said rotor being such that said stream imparts energy to said rotor by the drag of said stream on the roughened surface thereof, and by the lack of drag on the smooth, unchanneled, right-cylindrical, inner surface of said housing, and by its freedom for both circumferential and axial expansion.