Evaluation Of a High Speed, Light Load Phenomenon In Tilting-Pad Thrust Bearings
January 31 2013 -
Joseph J. Wilkes, Scan M. DeCamillo, Mark J. Kuzdzal, and James D. Mordell
This paper discusses a newly found high speed, light load hydrodynamic tilting-pad thrust bearing phenomenon. The phenomenon was first witnessed on centrifugal compressors operating above 10,000 rpm. Testing results have shown that in high speed, light load applications, thrust bearing babbitt temperatures are much higher than expected at low load conditions, and then drop to expected levels as the thrust load is further increased.
A Study Of Parameters That Affect Pivoted Shoe Journal Bearing Performance In High-Speed Turbomachinery
January 31 2013 -
Scan DeCamillo and Keith Brockwell
Journal bearing pad temperatures, oil flow requirements, and power losses can impose limitations on the design and operation of high-speed turbomachinery. Over the past few years, the authors have conducted extensive tests and studies of parameters that affect pivoted shoe journal bearing performance.
Test Results Comparing the Effect of Reverse Rotation on Offset Pivot Journal Bearing Pad Temperatures
January 31 2013 -
Scan DeCamillo, Keith Brockwell, and Waldemar Dmochowski
Babbitt temperatures in pivoted shoe bearings can be significantly reduced by offsetting the pad pivots in the direction of rotation. However, reverse rotation can occur in certain types of machinery under temporary or adverse conditions. The offset is then in the wrong direction and it becomes important to know if the bearing can withstand the reverse rotation operating conditions without damage. This paper compares pad temperature data from tests of a 152.4-mm, 60 percent offset bearing in forward and reverse rotation.
Journal Bearing Vibration and SSV Hash
January 31 2013 -
Scan DeCamillo, C. Hunter Cloud, Minhui He, and James M. Byrne
Peculiar, low-frequency, radial vibrations have been observed in various turbomachinery using tilt-pad journal bearings. Unlike discrete subsynchronous spikes that often indicate a serious problem, the vibrations are indiscrete and of low frequency and amplitude. The low level shaft indications have raised concern in witness tests of critical machinery, even in cases that comply with American Petroleum Institute (API) limits, owing to uncertainty regarding the cause and nature of the vibrations.
Special Design Features To Increase Rated Load Or Reduce White Metal Temperatures
January 31 2013 -
Kingsbury Engineering
Choosing the right bearing is easy, once you know how. To help, this article outlines the steps to take. It includes guidelines for bearing selection and curves for estimating power loss and oil flow requirements.
Directed-lubrication Bearing, LEG® By Kingsbury, Inc.
Design Notes:
The following guidelines for assigning load capacities to tilt-pad fluid film thrust bearings take into consideration theoretical analyses, field experience, and actual test results.
Current issues regarding unusual conditions in high speed turbomachinery
January 10 2013 -
Scan DeCamillo, Manager of R&D, Kingsbury, Inc
The hydrodynamic bearing is a remarkable device, capable of supporting extaordinary loads at high speeds for decades with little or no wear. However, there are a number of factors, including lubricant contamination, misalignment, vibration and other undesirable operating conditions, that can degrade bearing performance.
High Thrust Bearing Temperatures Due to Varnish
January 10 2013 -
David M. Casper, Engineering Service Coordinator, Kingsbury, Inc
Why is my thrust bearing running hot?
When you hear this question, it is natural to think that there is something wrong with the thrust bearing. This is not always the case. Bearing performance information can give you the symptoms of what is wrong with your machine or in this case the lubricant.
Turbulent Transition in Tilting Pad Journal Bearings
January 10 2013 -
Joseph J. Wilks, VP Engineering, Kingsbury, Inc
Tilting pad journal bearings can operate under a wide range of conditions of speed, load, load angle, oil temperature, and oil viscosity. Each one of these variables has an effect on the oil film, and an influence on whether the film is laminar, turbulent, or in transition. Other parameters affect the film as well including geometry such as the bearing diameter, length, clearance, preload, the number of pads and their orientation.
Dealing With Bearing Misalignment Issues
January 10 2013 -
David M. Casper, Engineering Service Coordinator, Kingsbury, Inc
How much static misalignment capability does a non-equalizing thrust bearing with spherical supports have?
A misalignment condition is based on the assumptions that the collar (or thrust disc) is perpendicular to the shaft, the collar surface is flat and smooth, and the runout is within an acceptable tolerance.
Getting To The Bottom Of Vibration Issues
January 10 2013 -
Michael J Brawley, VP Repair & Service Div, Kingsbury, Inc
In mid 2011, technicians at Kingsbury's Repair & Service Division in Hatboro, PA were consulted by the owner-operator of a 40-year-old, 114.3 MW vertical pumped storage turbine-generator located on a major river in the southwestern United States. The combination thrust and guide bearing assembly was installed beneath the generator, with a separate guide bearing assembly installed on the turbine. The 76\" diameter twelve-shoe thrust bearing was designed and produced by the original equipment manufacturer and featured a Kingsbury style, pin type, mechanical load equalizing system.
