In miniature gas turbines for UAV applications, traditional bearings exhibit a typical lifetime of only 25 hours due to excessive axial loading. Mainstream proposes 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 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 required 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. In Phase I, Mainstream and Florida Institute of Technology will design, fabricate, and test a prototype thrust bearing and prepare for Phase II integration and production.
Benefit: The development of a passive magnetic thrust bearing would provide a viable alternative to traditional bearings for high speed turbomachinery applications, increasing reliability and service life. Potential applications for this technology include compressors, pumps, turbines, and machine spindles.
Keywords: Magnetic Bearings, Magnetic Bearings, thrust bearings, Permanent Magnets, turbomachinery, Gas Turbines
