METHOD AND APPARATUS FOR MONITORING ROTARY MACHINES

• US 20080007256A1
• Filed: 07/06/2006
• Published: 01/10/2008
• Est. Priority Date: 07/06/2006
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Spalding, Michael Charles, Waters, Robert Lyngle
• Granted Patent: US 7,728,583 B2
• Time in Patent Office: Days
• US Class Current: 324/207.25
• CPC Class Codes: E21B 44/00 Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions
• CPC Class Codes: E21B 47/04 Measuring depth or liquid level
• CPC Class Codes: G01D 5/2515 with magnetically controlled switches, e.g. by movement of a magnet

Abstract

A method of determining the amount of travel of a rotating component that includes a rotor shaft includes providing a self-contained magnetically-powered encoder. The encoder includes an encoder rotor that extends outward from a sealed housing such that a clearance gap is defined between the rotor and housing. The encoder also includes at least one sensor configured to activate via magnetic flux and is configured to dissipate electrical signals with a power amplitude less than approximately one microwatt. The method also includes rotatably coupling the encoder to the rotor shaft. The method further includes measuring a first position of the encoder rotor and determining a first linear position measurement of the rotor shaft based on the encoder rotor. The method also includes rotating the rotor shaft to a second position and determining a direction of rotation and a second linear position measurement of the rotor shaft using the encoder.

Claims

1. A method of determining the amount of travel of a rotating component including a rotor shaft, said method comprising:

providing a self-contained magnetically-powered encoder that includes at least one encoder rotor that extends outward from a sealed housing such that a clearance gap is defined between the rotor and housing;

rotatably coupling the encoder to the rotor shaft;

measuring a first position of the encoder rotor;

determining a first linear position measurement of the rotor shaft based on the encoder rotor;

rotating the rotor shaft to a second position; and

determining a direction of rotation and a second linear position measurement of the rotor shaft using the encoder.

2. A method in accordance with claim 1 wherein providing an encoder further comprises:

providing an encoder including a plurality of magnets coupled within at least a portion of the rotor; and

coupling a plurality of switches to at least a portion of the housing, wherein the plurality of switches are oriented to receive magnetic flux generated from the plurality of magnets.

3. A method in accordance with claim 1 wherein rotatably coupling the encoder to the rotor shaft comprises:

providing a drawworks including a least one cable drum rotatably coupled to a drive shaft; and

rotatably coupling the encoder to the drawworks drive shaft.

4. A method in accordance with claim 3 wherein measuring a first position of the encoder rotor comprises coupling a drilling tool to at least one cable that is coupled to the drawworks cable drum.

5. A method in accordance with claim 1 wherein determining a first linear position comprises transmitting the encoder first position measurement to a remote processor that is programmed with at least one conversion algorithm.

6. A method in accordance with claim 1 wherein rotating the rotor shaft to a second position comprises re-positioning a drilling tool by rotating a cable drum and the at least one encoder rotor substantially simultaneously.

7. A method in accordance with claim 1 wherein determining a direction of rotation and a second linear position measurement of the rotor shaft comprises rotating at least one encoder magnet having a magnetic flux past at least one encoder switch, wherein the magnetic flux generated causes one of opening and closing the at least one switch.

8. A method in accordance with claim 1 wherein determining a direction of rotation and a second linear position measurement of the rotor shaft comprises:

rotating at least one encoder magnet having a magnetic flux past a plurality of encoder switches that are spaced circumferentially across a surface of the encoder housing, wherein the magnetic flux generated causes one of opening and closing of at least one encoder switch;

generating a plurality of output signals based on the movement of each encoder switch; and

transmitting the plurality of encoder output signals to a remote processor that includes at least one of a direction of rotation algorithm, and at least one conversion algorithm.

9. An encoder for use with a machine including at least one moveable member, said encoder comprising at least one sensor configured to activate via magnetic flux, said encoder configured to dissipate electrical signals with a power amplitude that is less than approximately one microwatt.

10. An encoder in accordance with claim 9 wherein said at least one sensor comprises a plurality of switches, wherein each of said switches configured to dissipate electrical signals with a power amplitude that is less than approximately one-third of one microwatt.

11. An encoder in accordance with claim 9 wherein the machine is a rotary machine and the moveable member is a rotatable member, said encoder further comprising:

at least one rotor configured to rotatably couple to the rotary machine at least one rotating member;

a sealed housing extending over at least a portion of said at least one rotor such that a clearance gap is defined between said housing and said rotor; and

a plurality of magnets coupled within at least a portion of said at least one rotor.

12. An encoder in accordance with claim 11 wherein said plurality of magnets are configured such that said plurality of magnets are spaced circumferentially substantially equidistantly from each other, about said at least one rotor, and a radially outermost portion of each of said plurality of magnets is substantially flush with an outer surface of said rotor.

13. An encoder in accordance with claim 11 wherein said at least one sensor is coupled to said housing and configured to receive magnetic flux from said plurality of magnets.

14. An encoder in accordance with claim 13 wherein said plurality of magnets control the operation of said at least one magnetically-powered sensor.

15. An encoder in accordance with claim 13 wherein said at least one sensor and said plurality of magnets are configured to generate a signal indicative of at least one of a direction of rotation of said rotor and a number of rotations of said rotor.

16. A measurement system for a drilling assembly including at least one rotatable member, said system comprising:

an encoder comprising at least one sensor configured to activate via magnetic flux, said encoder configured to channel electrical configured to dissipate electrical signals with a power amplitude that is less than approximately one microwatt; and

at least one processor coupled in electronic data communication with said encoder via at least one input channel, said at least one processor configured to receive and process at least one encoder output signal.

17. A measurement system in accordance with claim 16 wherein said at least one sensor comprises a plurality of switches, wherein each of said switches configured to dissipate electrical signals with a power amplitude that is less than approximately one-third of one microwatt.

18. A measurement system in accordance with claim 16 wherein said encoder further comprises:

at least one rotor configured to rotatably couple to said drilling assembly at least one rotatable member;

a sealed housing extending over at least a portion of said at least one rotor such that a clearance gap is defined between said housing and said rotor; and

a plurality of magnets coupled within at least a portion of said at least one rotor

19. A measurement system in accordance with claim 18 said plurality of magnets are configured such that said plurality of magnets are spaced circumferentially substantially equidistantly from each other, about said at least one rotor, and a radially outermost portion of each of said plurality of magnets is substantially flush with an outer surface of said rotor.

20. A measurement system in accordance with claim 18 wherein said plurality of magnets control the operation of said at least one sensor, and said at least one sensor and said plurality of magnets are further configured to generate a signal indicative of at least one of a direction of rotation of said rotor and a number of rotations of said rotor.