PNEUMATIC STEPPER MOTOR

• US 20120076681A1
• Filed: 10/11/2011
• Published: 03/29/2012
• Est. Priority Date: 08/09/2005
• Status: Active Grant

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Stoianovici, Dan, Patriciu, Alexandru, Mazilu, Dumitru, Petrisor, Doru, Kavoussi, Louis R.
• Granted Patent: US 10,024,160 B2
• Time in Patent Office: Days
• US Class Current: 418/1
• CPC Class Codes: F01C 1/10 of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member
• CPC Class Codes: F16H 1/32 in which the central axis of the gearing lies inside the periphery of an orbital gear
• CPC Class Codes: F16H 2001/325 comprising a carrier with pins guiding at least one orbital gear with circular holes
• CPC Class Codes: F16H 2001/327 with orbital gear sets comprising an internally toothed ring gear
• CPC Class Codes: F16H 35/00 Gearings or mechanisms with other special functional features
• CPC Class Codes: Y10T 74/19 Gearing

Abstract

A stepper motor suitable for use in a medical imaging environment has (a) a cylindrical central gear having an external surface with circumferentially distributed and radially directed teeth, (b) a shaft for mounting the central gear such that it is constrained to move in rotational motion about its centerline, (c) a cylindrical hoop gear having a bore with an internal surface having circumferentially distributed and radially directed teeth, (d) level arm crank mechanisms for mounting the hoop gear such that it is constrained to move in translational-circular motion about the central gear'"'"'s centerline, wherein this central gear is further configured to fit within the hoop gear'"'"'s bore in such a manner that a plurality of the central gear and hoop gear teeth intermesh and cooperate so that the planetary movement of the hoop gear causes the central gear to rotate, and (e) piston mechanisms for applying a fluid pressure driven force to specified points on the hoop gear so as to cause its movement.

Claims

17. A system for obtaining rotary motion by fluid pressure commutation, comprising:

a stepper motor having three ports for supplying fluid pressure;

three fluid-pressure-driven driving members, each said driving member being equally spaced around a perimeter of said stepper motor, each said driving member configured to be supplied by a respective port of said stepper motor, each said driving member being configured to apply a force generated by the fluid pressure of said respective port of said stepper motor so that said fluid pressure is commuted in a sequence through the respective ports of the stepper motor so as to cause motion of an output shaft of said stepper motor.

18. The system of claim 17, wherein the sequence is a full step commutation sequence.

19. The system of claim 17, wherein the sequence is a half step commutation sequence.

20. A method of obtaining rotary motion, comprising:

providing a stepper motor having at least three ports for supplying fluid pressure;

providing a three fluid-pressure-driven driving members, each said driving members being equally spaced around a perimeter of said stepper motor, each said port configured to supply the fluid pressure for the respective driving member of said stepper motor; and

commuting fluid pressure in a sequence so as to cause motion of an output shaft of said stepper motor.

21. The method of claim 20, wherein the sequence is a full step commutation sequence.

22. The method of claim 20, wherein the sequence is a half step commutation sequence.