Posts Tagged ‘bearings’

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Lift Oil Pumping System

March 21, 2016

TRI has recently completed a pair of lift oil pumping skids. They will produce 5 gallons per minute at 3000 p.s.i. The system will reduce the wear on bearings when the unit is on turning gear. The lift oil will also reduce the load on the turning gear and turning motor.

LiftOilSystem

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Fluid Drive Upgrades

May 14, 2014

Back in 2007, Dr. Mel created a presentation for fluid drive upgrades. This presentation explains how fluid drives are used specifically with boiler feed pumps. The operational history and the changes to the standard practices led to issues for which TRI has engineered solutions.

 

 

 

 

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Controlling Oil Whirl with a Pressure Dam Bearing

March 28, 2014

In this video, we explain oil whirl and how a 2nd area of high pressure created by a pressure dam can tame the vibration caused by oil whirl.

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Bearing Dovetail Grooves

March 25, 2014

Many bearing in the field use a dovetail bore design. TRI Transmission and Bearing Corp. explains why the dovetail design leads to Babbitt wipes and bearing failures.

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New Tech Note

February 8, 2013

It has been nearly two years since our last Tech Note, but today we have released the latest write up. This month’s topic is about bearings for turbine-generators found in nuclear electric generation plants.

Many nuclear plants run at 1800 RPM where many fossil fueled steam plants run at 3600 RPM. Considering the generator, half the speed means twice the poles dramatically increasing the weight of the rotor.

The new Tech Note focuses on heavily loaded bearings.

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WARNING: Cracks Found in Westinghouse Cast Steel Bearings

November 9, 2010

3 Case studies with solutions…read more

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Tin-Copper Bondline Embrittlement and Debonding Phenomena

October 28, 2010

A simple literature review, or search on the Internet for “intermetallic compounds” would lead one to believe that this represents the state of the art in material science.  While the study of many new compounds is on the leading edge of technology, the intermetallic nature of copper and tin in an alloy form has been studied for more than 5000 years.  Without the aid of high tech tools, the Chinese developed the beta bronze alloy form of tin and copper some 1400 years ago.  This was the first metal that could be intentionally heat treated to provide a wide range of mechanical properties.  In more recent research, much attention has been paid to the formation of Cu6Sn5 and Cu3Sn intermetallic compound layers, and their effect on solder joints in electronic assembly.  Unfortunately, little, or no attention has been paid to the identical reaction that occurs when bonding a tin based Babbitt to a copper alloy backing material typical of many fluid film bearings used in industry today.

My first direct exposure to the resultant phenomenon of the formation of these compounds came about 10 years ago.  During the dis-assembly of a high speed gas compressor, the thrust pads were removed from the unit for inspection.  In this particular bearing, the pads were designed with ASTM-B23 Grade 2 Babbitt bonded to a copper alloy containing approximately 2% chrome for increased mechanical strength.  In this application, the high sliding velocity present in the oil lubricated thrust bearing would have yielded unacceptably high bearing temperatures if conventional steel backing material had been used.  The copper alloy backing material was used due to its high thermal conductivity to provide improved bearing performance.  In this instance, following successful dimensional checks, and ultrasonic inspection of the Babbitt bond, the pads were returned to the compressor deck to be re-installed in the machine.  During the installation process, one of the pads was inadvertently dropped from a height of about three inches on to a steel workbench.  As a result of this minor impact, the Babbitt completely separated from the copper alloy backing material.  This was indeed somewhat disturbing that the Babbitt could fall off of an otherwise acceptable part that was ready for installation in a very expensive machine that operates in excess of 10,000 RPM.

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