PNEUMATIC STEPPER MOTOR

摘要

A stepper motor suitable for use in a medical imaging environment has (a) a cylindrical central gear (10) having two ends (11a, 11b) with a center line (12) extending between these ends, and an external surface (13) with circumferentially distributed and radially directed teeth (14), (b) a means for mounting the central gear (10) such that it is constrained to move in rotational motion about its centerline (12), (c) a cylindrical hoop gear (20) having a bore (22) with an internal surface (24) having circumferentially distributed and radially directed teeth (26), (d) a means for mounting (40) the hoop gear such that it is constrained to move in translational-circular motion about the central gear's centerline (12), wherein this central gear (10) is further configured to fit within the hoop gear's bore (22) in such a manner that a plurality of the central gear (14) and hoop gear (26) teeth intermesh, and wherein these hoop gear teeth (26) are further configured so as to cooperate with the central gear teeth (14) so that the planetary movement of the hoop gear teeth causes the central gear (10) to rotate, and (e) a means for applying a fluid pressure driven force to specified points on the hoop gear (20) so as to cause its movement.