Recent engine developments toward higher loads (down-sizing) and thinner oil films have increased the severity of plain bearing operating conditions [1]. These factors, combined with lower viscosity oils, have resulted in a greater sensitivity of bearings to damage by foreign debris particles. Traditional highly embeddable materials, such as lead, are being progressively phased out. This lead-free trend observed in the passenger car market is likely to spread to the truck market in the future. As a result, it is becoming increasingly challenging to balance the conflicting hard and soft requirements of bearing materials. Although new generations of bearing materials, particularly polymeric overlays, have shown excellent fatigue and wear capabilities [2], they would benefit from enhanced embeddability properties. This demand has led MAHLE to take a new approach with the development of a polymeric overlay material that has both hard and soft characteristics. This newly developed soft-phase copolymer resin has been synthesized from monomers selected to give the desired properties. Conventional polyamide-imide (PAI) monomers have been combined with polydimethylsiloxane (PDMS) macromonomers. PDMS was selected to improve embeddability as it is softer and offers more flexibility than PAI. Via a polymerization reaction, chains of hard, fatigue resistant PAI are alternately combined with short chains of PDMS. This produces a polymer matrix which has a very fine distribution of soft phase due to the microphase segregation created as the soft and hard segments of neighboring polymer chains preferentially align with each other [3,4]. The relative lengths of the hard and soft sections can be “tuned” to produce domains of differing size and therefore adjust the balance of properties. Experiments have been carried out varying the overall percentage of PDMS and also with the molecular weight of the PDMS segments. Initial embeddability testing has shown an improvement in embedment over current polymer products and further work is ongoing to optimize this new resin system.
Skip Nav Destination
Article navigation
September 2016
Research-Article
Improved Embeddability for Polymeric Bearing Overlays
Ronald Brock
Ronald Brock
Search for other works by this author on:
David Latham
Ian Laing
Ronald Brock
Contributed to the Internal Combustion Engine Committee for publication in the ASME Journal of Engineering for Gas Turbines and Power. Manuscript received January 27, 2016; final manuscript received February 1, 2016; published online March 22, 2016. Editor: David Wisler.
J. Eng. Gas Turbines Power. Sep 2016, 138(9): 092805 (8 pages)
Published Online: March 22, 2016
Article history
Received:
January 27, 2016
Revised:
February 1, 2016
Citation
Latham, D., Laing, I., and Brock, R. (March 22, 2016). "Improved Embeddability for Polymeric Bearing Overlays." ASME. J. Eng. Gas Turbines Power. September 2016; 138(9): 092805. https://doi.org/10.1115/1.4032714
Download citation file:
Get Email Alerts
Cited By
Image-based flashback detection in a hydrogen-fired gas turbine using a convolutional autoencoder
J. Eng. Gas Turbines Power
Fuel Thermal Management and Injector Part Design for LPBF Manufacturing
J. Eng. Gas Turbines Power
An investigation of a multi-injector, premix/micromix burner burning pure methane to pure hydrogen
J. Eng. Gas Turbines Power
Related Articles
Seizure Improved Lead-Free Electroplated Bearing Overlay System for Heavy-Duty Truck and Off-Highway Applications
J. Eng. Gas Turbines Power (November,2018)
In Vitro Study of Backside Wear Mechanisms on Mobile Knee-Bearing Components
J. Tribol (April,2006)
A Systems Approach to the Solid Lubrication of Foil Air Bearings for Oil-Free Turbomachinery
J. Tribol (January,2004)
Related Chapters
Cemented Carbides and Cermets
Brazing Handbook, Volume 3, 6th Edition
Surface Analysis and Tools
Tribology of Mechanical Systems: A Guide to Present and Future Technologies
Friction and Wear of Polymers and Composites
Tribology of Mechanical Systems: A Guide to Present and Future Technologies