ASBTDC Client Wins DOE Funding for Nanomaterial Journal-Bearing Coating
March 21st, 2017 by Rebecca Todd
Fayetteville-based company SurfTec recently received an award of $1.2 million from the Department of Energy in response to a special funding announcement.
Through this two-year DOE Next Generation Electric Machines: Enabling Technologies award, SurfTec will explore implementing a nanoparticle-based coating as a replacement for traditional journal bearing materials.
Journal bearings are mechanical devices used to reduce friction between moving parts and are a key component of engines and generator systems, particularly those that require extensive motion.
SurfTec founders Dr. Samuel Beckford, CEO, and Dr. Min Zou, CTO, have backgrounds in surface engineering, materials science, tribology, and nanomechanics. Dr. Min Zou, a professor in the Department of Mechanical Engineering at the University of Arkansas, Fayetteville, directs the Nano Mechanics and Tribology Laboratory.
Dr. Beckford received his Ph.D. from the Microelectronics-Photonics Graduate Program at the UA and has worked as a research assistant at the NMTL for the past six years in research related to the proposed coating technology. His research on PTFE composite coatings has led to six peer-reviewed publications and a pending patent, and his work received the Al Sonntag Award (2013) presented by the Society of Tribologists and Lubrication Engineers.
The Problem: Electric motor failure and issues with traditional materials
Root cause failure analysis of AC induction motors has shown that 51% of break downs are a result of bearing failure. Consequently, there has been much focus in developing new bearing technology to improve the reliability of electric motors.
Currently, tin and lead-based Babbitt alloys are commonly used in journal bearings as sacrificial layers that prevent damage to the bearing and journal during start/stop or transient operation when direct journal and bearing contact is unavoidable.
Traditional Babbitt alloys are susceptible to wear during start/stop of electric motors when an oil film does not separate the surface of the bearing and journal. Hydraulic jacking systems are often used to provide a high-pressure oil supply that allows full film lubrication between the bearing and journal.
Tin alloys are the most common Babbitt materials currently used in high speed, megawatt class, medium voltage (MV) electric motors and generator systems. At $7.36/pound, tin is significantly more expensive than lead and other bearing materials. Tin is also considered a conflict mineral. The Dodd-Frank Wall Street Reform and Consumer Protection Act has placed strict reporting requirements on manufacturers that use tin (cassiterite).
“The use of low-friction polymer coatings on the surface of bearings is an attractive option to prevent adhesion and allow low friction during start/stop or transient operation, potentially eliminating the need for hydraulic jacking systems, reducing cost, complexity and oil consumption,” said Beckford.
The application of low friction polymer coatings will enable the achievement of the DOE’s goal to replace lead and bismuth in journal bearings while significantly reducing friction losses during start/stop or transient operation.
SurfTec’s technology can potentially replace the use of tin-based Babbitt alloys. “Using low-friction polymer coatings as overlays on metallic liners would allow less expensive and more readily available liner materials to be used,” he said.
SurfTec’s Proposed Solution
“The successful incorporation of the proposed nanomaterial coating in journal bearings has the potential of reducing friction by at least 10% and increasing wear-life by over 40% in the boundary/mixed lubrication regimes,” said Beckford. These potential outcomes enable the DOE’s Advanced Manufacturing Office’s goal of reducing energy losses in high speed, megawatt class, MV electric motors and generator systems. “SurfTec’s technology will simultaneously remove lead and bismuth, which present environmental risks,” Beckford noted.
SurfTec’s proposed coating has been studied and developed as a solid lubricant coating over the past six years. Lab-scale testing and comparison to commercial solid lubricant coatings has shown favorable results that have attracted much interest from industry.
“The DOE Next Generation Electric Machines: Enabling Technologies funding opportunity will allow us to overcome the technical hurdles to validate the use of this technology in journal bearings for high speed, megawatt class, MV electric motors and generator systems,” said Beckford. The execution of this project will allow the realization of critical proof points needed in this industry.
The Arkansas Small Business and Technology Development Center provided access to market report information that allowed SurfTec to identify the market size and growth rate of the targeted large scale journal bearing for high speed, megawatt class, MV electric motor industry as a whole and identify potential customers in industry leaders. “Access to reputable industry reports, such as the ones provided by ASBTDC, are typically very costly, and we were very grateful to be able to receive these free of charge and in a timely fashion,” said Beckford.
“The SBIR/STTR Phase I Proposal Writing workshops and live webinars offered by the ASBTDC were also very instrumental in preparing us to write a strong DOE proposal. It was especially helpful to be able to hear from government agency reviewers and entrepreneurs that had good advice on what constituted a strong proposal,” Beckford noted.
Advice for Prospective DOE Funding Applicants
“I would also recommend that you look at previous successful proposals and previous rejected proposals to get a better picture of what reviewers are looking for,” said Beckford. “To help you gain a better picture, talk to people who have gone through the proposal submission process before. Carefully review the proposal writing guideline to make sure you answer all questions. Carefully review the topic area to make sure you are a good fit.
“Finally, and just as important as the above, make sure your proposal is easy to follow. Provide tables and schematics that make the reading enjoyable and easy to follow; define the terminology used; provide numbered lists where appropriate. This has been the biggest compliment we have received. It appears that many people make the mistake of filling proposals with as much information as possible, making it so convoluted that in the end it is too hard to follow, annoying the reader rather than encouraging them to continue reading.”