Innovative Passive Magnetic Thrust Bearings for High-Speed Turbomachinery

Period of Performance: 09/14/2011 - 03/14/2013


Phase 2 STTR

Recipient Firm

Mainstream Engineering Corporation
200 Yellow Place Array
Rockledge, FL 32955
Firm POC
Principal Investigator

Research Institution

University of Colorado Boulder
572 UCB
Boulder, CO 80309
Institution POC


In miniature gas turbines for UAV applications, traditional bearings exhibit a typical lifetime of only 25 hours due to excessive axial loading. Mainstream proposed 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 s Phase I design highlighted the advantages of using passive magnetic bearings for this application: Non-contact operation Sufficient force capacity Sufficient stiffness to maintain axial tolerance Size similar to traditional bearings These advantages have been shown through both simulation and static testing. The tests of the prototype demonstrated a 201 N load capacity, meeting the project goals. The remaining tests in Phase II will show how these bearings perform at high rotational speeds and in a gas turbine environment. Upon the conclusion of Phase II, passive magnetic bearings will prove to be a viable solution for UAV miniature turbines and other military and commercial applications.