Southwest Research Institute

Cecil M Teller

Hegeon Kwun

Gary Lane Burkhardt

Roy C Meyer

Kendall R Swenson

A device and method for the non-contact measurement of dynamic torsion in a rotating shaft using magnetostrictive sensors (MsS). The monitoring and detection system has specially configured magnetostrictive signal detectors that include inductive pick-up coils, in which signals corresponding to localized shaft torques are induced. The basic system sensor utilizes either a permanent DC bias magnet positioned adjacent the rotating shaft or applies a residual magnetic field to the shaft. The techniques described in conjunction with the system are particularly advantageous for on-line monitoring of loaded rotating shafts that are integral parts of power trains, by providing a low-cost and a long-term sensor for acquiring dynamic data of the shaft portion of the machinery system being monitored and/or controlled.

Measurement of torsional dynamics of rotating shafts using magnetostrictive sensors

A method and apparatus is provided for the sensing, collection, and analysis of information on combustive and mechanical events occurring within an operating internal combustion engine through the measurement of mechanical stress waves present within the engine. The system includes a magnetostrictive sensor placed in mechanical compliance with the engine, preferably the engine block, which detects and translates stress waves into an electrical signal that is filtered and amplified for recording and/or for analysis. Information regarding the frequency, amplitude, and timing changes within the signal is utilized to characterize the ordinary operation of the engine and to identify anomalous events. The system includes a means for maintaining a signal record and comparing signal features with past records for a particular engine or with standard signal features associated generally with certain engine events. The system apparatus can be implemented in a laboratory or technical setting or may be configured as an on-board monitoring system with correctional feedback capabilities.

Apparatus and method for monitoring engine conditions, using magnetostrictive sensors

A method and apparatus for the inspection of ferromagnetic and non-ferromagnetic pipes, tubes or other cylindrical shell structures utilizing the magnetostrictive effect to detect defects such as corrosion pits, wall thinning, and cracks within the structure under evaluation. The apparatus and method constitute an active testing application, wherein 1) a transmitting coil element generates a mechanical pulse within a cylindrical shell structure through the magnetostrictive effect and a second coil detects reflected mechanical waves within the pipe, this by the inverse magnetostrictive effect, or 2) a single sensor functions as both transmitter and detector. The present invention also anticipates a passive monitoring application with a detection coil that continuously monitors ferromagnetic or non-ferromagnetic tubes, pipes, etc., for mechanical or acoustic wave emissions and either records this monitored information or alerts the appropriate personnel to the existence of mechanical or acoustic wave emissions indicative of deterioration. Non-ferromagnetic pipes, tubes, etc., are made amenable to inspection by attaching a layer of ferromagnetic material such as nickel on either the inner or outer walls of the pipes, tubes, etc. by plating or bonding such material in a local area where the sensor is to be placed.

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Austin, TX, United States of America

Cecil M Teller