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Tech Note January 1996

Technical Notes from Dr. Mel Giberson, P.E. – TRI President


Factor influencing Fluid Drive Reliability are:

  • Suitability to the application: size, speed, power, turndown ratio.
  • Component design features, materials and details
  • The vibration and temperature monitoring instrumentation
  • Foundation, sole plate, grout and alignment retention
  • Associated equipment: drivers, gears, flexible couplings and loads.
  • Operation practices
  • Rebuild and maintenance practices
  • Scoop tube actuator
  • Oil conditioning system
  • Speed/power control system


  • High vibration in certain load range(s)
  • Sensitivity to misalignment to adjacent equipment
  • Broken vanes in the impeller, runner or vaneplate
  • Poor control of output shaft speed in certain load ranges(s)
  • Oil leakage or oil vapor leakage out of shaft seals or vent
  • Removal of “pilot” bearing, replaced by additional bearing on the output shaft
  • Damaged/worn scoop tubes, scoop tube linkage, slide plates, brackets, etc.
  • Problems with AC/DC oil pump controls, during operation and/or unit trips
  • Repeated damage of journal bearings(s). Need for bearings with undersized bores.
  • Updated and simplified installation, operation and maintenance manuals, in English
  • Vibration and/or temperature sensing/ monitoring/ diagnostic system(s) or current design
  • Replacing an air operated scoop tube actuator with an electrically operated one.
  • Brakes requiring frequent attention. Brakes that will positively stop the fluid drive output shaft.
  • Adaptation of fluid drive instrumentation and controls to the Distributed Control System for the entire unit.
  • Automatic maximum (or minimum) output shaft speed or power required by the existing application, or for a new/revised application.
  • Spare parts problems: Obtaining desired parts that fit properly with acceptable surface finishes; obtaining modified parts made of proper materials to suit your particular application
  • Worn/damaged flexible coupling on input or output end, including the large diaphragm couplings typically used on Westinghouse turbines.

Turbo Research, Inc. has successfully addressed these issues for fluid drives in almost all applications for approximately 25 years. TRI has developed understandings and solutions for these Fluid Drive concerns for all applications, sizes power ratings, speeds and manufacturers, as evidenced by 6 recent U.S. Patents issued to TRI, the leader in Fluid Drive Technology in the U.S. today.

New Fluid Drive Systems for NEW or EXISTING applications designed and built by TRI:

Turbo Research, Inc. designs and manufactures New or Rebuilt FLUID DRIVE SYSTEMS addressing the above concerns so as to be TROUBLE FREE form the INITIAL Start-up. TRI’s facilities are located in Lionville, PA.

New U.S. Patent to be Issued to TRI:

A new U.S. Patent will be issued to TRI for a design of a QUICK DISCONNECT flexible coupling for this application: A rigidly mounted fluid drive which is driven by a flexible coupling connected to an extension shaft mounted in a sliding housing, such as the front end of a GE Large Steam Turbine-Generator. The existing flexible coupling which is located in the nose section of the turbine front standard is removed and the nose is modified slightly. A new disconnect coupling with hydraulic actuating arrangement is installed. This arrangement can operate while the standard slides back and forth as a function of turbine temperature.

Upcoming Exhibition of TRI Engineering Services and Products: The 17th Energy Generation Conference will be held in Bismark, North Dakota on January 16-18, 1996 at the Civic Center. Stop by our Booth #111 and say hello.

Over 15,000 MW of Electrical Generation Depend Upon TRI Bearings

Tel: 610-363-8570 or 800-363-8571 Fax: 610-524-6326 EMail:

TRI Answers phone calls, returns e-mails and responds to fax inquiries

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