Patent ID: 8439662

Claim:
A vane air motor comprising: a motor housing comprising a cylindrical wall having a circular cylindrical inner peripheral surface, and a first end wall and a second end wall that are attached to opposite ends, respectively, of the cylindrical wall, the motor housing having a rotor chamber therein; a rotor disposed in the motor housing rotatably about an axis of rotation parallel to and spaced from a center axis of the circular cylindrical inner peripheral surface, the rotor comprising an output shaft portion extending through the second end wall along the axis of rotation, the rotor further comprising a support shaft portion extending into the first end wall; and vanes fitted to the rotor; wherein compressed air is supplied into the rotor chamber to rotationally drive the rotor by the compressed air, and the compressed air that has finished rotationally driving the rotor is discharged to an outside of the rotor chamber from a plurality of air discharge openings that open on the circular cylindrical inner peripheral surface; wherein the plurality of air discharge openings comprise a central air discharge opening that is central in the axial direction and a plurality of air discharge openings disposed at each side of the central air discharge opening in the axial direction, the air discharge openings at each side of the central air discharge opening being arranged such that a distance of the air discharge openings from the central air discharge opening increases toward an upstream side of a direction of rotation of the rotor as a distance from the central air discharge opening increases in the axial direction, the plurality of air discharge openings being spaced from each other such that each pair of the air discharge openings adjacent to each other in an axial direction of the motor housing overlap each other as seen in a circumferential direction of the motor housing and in the axial direction.