System and method for sensing torque on a rotating shaft

• US 7,322,250 B1
• Filed: 08/15/2005
• Issued: 01/29/2008
• Est. Priority Date: 04/09/2002
• Status: Expired due to Fees

• Current Assignee: Rockwell Automation Technologies Incorporated (Rockwell Automation, Inc.)
• Original Assignee: Rockwell Automation Technologies Incorporated (Rockwell Automation, Inc.)
• Inventors: Discenzo, Frederick M.
• Primary Examiner(s): NOORI, MASOUD H
• Application Number:
  US11/203,790
• Time in Patent Office: 897 Days
• Field of Search: 738/00
• US Class Current: 73/800
• CPC Class Codes: G01L 1/241 by photoelastic stress analysis
• CPC Class Codes: G01L 3/12 involving photoelectric means

Abstract

A system and method relating to the measuring of torque in a rotating shaft is provided. An optical torque sensing system comprises a rotating shaft, wherein a sleeve of photo-elastic material overlays a portion of the shaft. A light emitting component delivers light into the photo-elastic material, wherein the light delivered by the light emitting component is directed through the photo-elastic material along an axis of the rotating shaft. A capturing component captures the light that exits the photo-elastic material. The exiting light comprises fringe pattern data, and a computing system computes torsion strain of the shaft based at least in part on the fringe pattern information.

Claims

1. An optical characteristic inspection system comprising:

a layer of photo-elastic material that overlays a portion of a structure associated with a motor;

a measurement component that delivers a signal into the photo-elastic material, the signal is re-directed through the photo-elastic material in a substantially parallel direction with respect to an axis of the structure;

an analysis component that receives light exiting the photo-elastic material, the exiting signal associated with structural degradation characteristics; and

a correction component that controls a material located at each end of the motor based at least in part on analysis of the exiting signal.

2. The system of claim 1, the signal is delivered orthogonally with respect to the axis of the structure.

3. The system of claim 1, the material re-positions a bearing associated with the structure.

4. The system of claim 1, the material is a smart material.

5. The system of claim 4, the smart material is at least one of a Shape Memory Alloy, a piezoelectric ceramic and an electroactive polymer.

6. The system of claim 1, the structure is at least one of a shaft, a coupler, and a composite joint.

7. The system of claim 1, the structural degradation characteristics are at least one of fatigue, cracking, breakage, rate of degradation, amount of degradation, and misalignment.

8. The system of claim 1, the signals are at least one of:

an optical signal, an electromagnetic signal, a RF signal, and an IR signal.

9. The system of claim 1, further comprising a joint integrity verifier that detects defective composite joints.

10. The system of claim 9, the correction component modifies parameters of the structure, based at least in part on information received from the joint integrity verifier.

11. The system of claim 1, at least one collar of the photo-elastic material is coated with a reflective substance.

12. The system of claim 1, the signal passes along a longitudinal axis of the structure twice, initially transmitted and then reflected.