Bent shaft motor

• US 5,747,915 A
• Filed: 08/19/1996
• Issued: 05/05/1998
• Est. Priority Date: 08/19/1996
• Status: Expired due to Fees

• Current Assignee: Sandia Corporation (Martin Marietta Corporation)
• Original Assignee: Sandia Corporation (Martin Marietta Corporation)
• Inventors: Benavides, Gilbert L.
• Primary Examiner(s): BUDD, MARK OSBORNE
• Application Number:
  US08/699,279
• Time in Patent Office: 624 Days
• Field of Search: 310/82, 310/306, 310/307, 310/309, 310/323, 310/328, 310/330-331
• US Class Current: 310/331
• CPC Class Codes: H02N 2/105 Cycloid or wobble motors; Harmonic traction motors

Abstract

A nonelectromagnetic motor comprising a base, a bent shaft which is rotable relative to the base wherein the bent shaft comprises a straight portion aligned with a main axis and an offset portion that is offset with respect to the main axis; and a drive means for driving the offset portion of the bent shaft along a generally circular path in a plane perpendicular to the main axis to rotate the bent shaft. The bent shaft and drive means for driving the bent shaft can be selected from piezoelectric, magnetostrictive, rheological and shape memory alloys. The drive means of the nonelectromagnetic motor can additionally comprise a shell which shell surrounds and houses the bent shaft and precesses or gyrates which in turn causes the bent drive shaft to rotate. The nonelectromagnetic motor does not rely on friction for the application of torque upon a rotor.

Claims

1. A bent shaft motor, comprising:

a base;

a drive shaft which is rotable relative to said base wherein said drive shaft comprises a straight portion aligned with a main axis and an offset portion that is offset with respect to said main axis; and

compliant drive means extending between said base and said offset portion of said drive shaft wherein sequentially flexing of said drive means drives said offset portion along a generally circular path in a plane perpendicular to the main axis to rotate said drive shaft.

2. The bent shaft motor of claim 1 wherein said drive means comprises a compliant structure surrounding said shaft.

3. The bent shaft motor of claim 2 wherein said straight portion further comprises an output shaft which has an axis of rotation and wherein said structure comprises a shell which precesses about the axis of rotation of the output shaft.

4. The bent shaft motor of claim 1 further comprising an exciter assembly.

5. The bent shaft motor of claim 4 wherein the exciter assembly is a piezoelectric assembly.

6. The bent shaft motor of claim 2 wherein the structure further comprises at least one or more benders wherein said benders surround the drive shaft.

7. The bent shaft motor of claim 6 wherein each bender is fixed to at least one flexible ring.

8. The bent shaft motor of claim 7 wherein said drive shaft has a contour and each bender is shaped to conform to the contour of the drive shaft.

9. The bent shaft motor of claim 8 wherein the benders comprise piezoelectric benders.

10. The bent shaft motor of claim 2 wherein the structure comprises shape memory alloy material which in the presence of heat will conform to a preferred shape.

11. The bent shaft motor of claim 10 wherein said structure conforms to the shape of the drive shaft.

12. The bent shaft motor of claim 11 wherein said motor is externally driven by selectively applying a heat source to the exterior of the structure to induce rotary motion in a clockwise or counter-clockwise direction.

13. The bent shaft motor of claim 2 wherein the structure further comprises at least one wire made of shape memory alloy material.

14. The bent shaft motor of claim 3 wherein said output shaft extends beyond said shell and said base.

15. The bent shaft motor of claim 1 wherein said base further comprises a passageway therethrough.

16. The bent shaft motor of claim 15 wherein said shaft extends beyond the shell through said passageway.

17. The bent shaft motor of claim 3 wherein the shell is cylindrically shaped.

18. The bent shaft motor of claim 1 wherein said drive shaft further comprises parallel but offset extremities.

19. The bent shaft motor of claim 1 wherein said drive shaft comprises a bent shaft.