Abstract: A pneumatic rotary motor comprising a body to which is secured a bracer bushing closed by a cover. A deformable bushing is freely housed within the bracer bushing and is interposed between the cover and the casing. The bushing has a bore and two opposed longitudinal circular recesses extending from the bore. Two intermeshed rotary gears extend longitudinally in the bushing and are centered in a respective recess, the gears teeth sealably contacting the internal bushing along the circular recesses. The gears have shafts respectively supported for rotation in the cover and the casing and form opposed working chambers on either side of the recesses and in communication with openings provided in the cover for the intake and exhaust of a fluid. Screws, or the like, are mounted in the bracer bushing for abutting against the internal bushing to produce deformation thereof at the recesses for effecting sealed contact with the teeth of the gears.