System for determining shaft load parameters including shaft windup angle per unit length, torque output and power output in a generally cylindrical rotating shaft

• US 5,452,616 A
• Filed: 12/20/1994
• Issued: 09/26/1995
• Est. Priority Date: 02/01/1993
• Status: Expired due to Fees

• Current Assignee: Liberty Technology Company Limited
• Original Assignee: Liberty Technology Company Limited
• Inventors: Leon, Robert L., Moffa, Anthony L.
• Primary Examiner(s): Chilcot, Jr., Richard E.
• Assistant Examiner(s): Dougherty, Elizabeth L.
• Application Number:
  US08/359,965
• Time in Patent Office: 280 Days
• Field of Search: 73/862.08, 73/862.191, 73/862.21, 73/862.23, 73/116, 415/30
• US Class Current: 73/862.08
• CPC Class Codes: G01L 3/101 involving magnetic or electromagnetic means
• CPC Class Codes: G01L 3/109 involving measuring phase difference of two signals or pulse trains
• CPC Class Codes: G01L 3/242 by measuring and simultaneously multiplying torque and velocity

Abstract

A system for determining shaft load parameters including shaft windup angle per unit length, torque output and power output in a generally cylindrical rotating shaft having an outer surface and a longitudinal axis extending through the center thereof includes a plurality of probes spaced apart from each other. Each probe has a first end and a second end, the first end of each probe being in facing relationship with the rotating shaft. A rigid frame commonly supports all of the probes at a predetermined distance from the outer surface of the shaft. The frame is supported in such a manner that the frame may vibrate or displace relative to the rotating shaft essentially as a rigid body. Targets on the outer surface of the rotating shaft are located for triggering a probe output response each time during shaft rotation that a target passes the first end of one of the probes. A calculator calculates the torque induced shaft windup angle of the rotating shaft based in part on the probe trigger times and the spacing of the probes.

Claims

1. A turbine train monitoring system for identifying a turbine in the train having a lagging output torque, each turbine in the train having a load end and a power output, the monitoring system comprising:

a plurality of shaft power systems, each for measuring a shaft torsional load parameter, at least one system located on a shaft section between each turbine in the train to be monitored;

differencing means for determining the power output of each turbine as the difference between the shaft power at the train load end and the shaft power at the train end opposite the load; and

comparison means for identifying a turbine in the turbine train that is supplying less power than the other turbines and a turbine that is supplying less power as time goes by thereby indicating a degrading condition.