Mainstream Engineering Awarded Contract from the Navy for Passive Magnetic Bearings

ROCKLEDGE, FL – July 15th, 2010 – Mainstream Engineering Corporation, leading research, and development company specializing in advanced thermal control and energy conversion, has been awarded a contract from the Navy to design and build passive magnetic thrust bearings for high-speed turbomachinery.

In miniature gas turbines for UAV applications, traditional bearings exhibit a typical lifetime of only 25 hours due to excessive axial loading. Mainstream has proposed to use a passive, permanent magnet thrust bearing to alleviate this problem and increase service life to over 1000 hours. Since this type of bearing is non-contacting, it can operate at very high rotational speeds with minimal heat generation and extended operating life. Mainstream has already performed a preliminary design for this innovative thrust bearing which is small, lightweight, and requires no power or active control. The bearing geometry has already been optimized for size and weight and our simulations have shown that the bearing achieves the Navy’s target of 200 N bidirectional force capacity while maintaining an axial tolerance of ± 0.1 mm and a size that is competitive with traditional bearings. The design also provides a mechanism for passive damping to mitigate vibrations in the axial direction. In addition, this novel geometry lends itself well to mass production and is flexible enough to easily allow scaling to different sizes and capacities. Mainstream, with the help of researchers at the Florida Institute of Technology, will design, fabricate, and test a prototype thrust bearing. At the conclusion of the project, Mainstream will prepare the unit for integration and testing in the Navy’s miniature gas turbine engines.