Operation of an Electromagnetic Eddy-Current Damper with a Supercritical Shaft

[+] Author and Article Information
J. R. Frederick

Balseal Engineering, Santa Ana, CA

M. S. Darlow

Technion-Israel Institute of Technology, Technion City, Haifa, Israel

J. Vib. Acoust 116(4), 578-580 (Oct 01, 1994) (3 pages) doi:10.1115/1.2930467 History: Received February 01, 1992; Revised August 01, 1993; Online June 17, 2008


A basic problem inherent with the operation of supercritical shafting is the application of appropriate external damping, which is generally necessary to suppress nonsynchronous instabilities and limit the synchronous response of even a well-balanced shaft. Typically, coulomb or squeeze film-type dampers are used, in which case the damping properties tend to change with temperature, and the necessary contact results in additional torque loading and wear. An alternative damping method currently under investigation is the application of a noncontact electromagnetic damper that dissipates energy through induced eddy-currents generated in a small disk mounted to, and rotating with the shaft (Frederick, 1990). Research is underway on the design and development of a damper of this type that could eventually lend itself to active control applications. The objectives of this investigation are the initial design of a magnetic circuit, an appropriate d-c power supply, and the characterization of preliminary performance experiments on a composite shaft. Damper operation was evaluated during rotating shaft tests and compared to prior tests which involved the use of a permanent magnet eddy-current damper. This Note concerns some interesting results obtained from these preliminary tests. The damper worked well at low speeds, but some high-speed stability problems were encountered. Potential solutions to these problems as well as areas of future research are discussed.

Copyright © 1994 by The American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.





Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In