Damping for Increased Stability

Damping decreases vibrations by removing energy through resistance to motion. For rotating equipment, damping is necessary to control vibrations and prevent them from damaging the rotor, bearings or other components in the machine.

Using an engineered damper can increase stability, reduce rotor response, increase the separation margin between operating speed and critical speeds, reduce forces transmitted from rotor to ground, reduce pedestal vibrations, reduce bearing wear, and decrease sensitivity to changes to the rotor, such as material buildup on a rotating component.

To learn about the particular benefits of ISFD® technology – the integral squeeze film damper – read the article on engineerlive.com.

Advanced Bearing Technology Eliminates Subsynchronous Steam Turbine Vibrations

By Jong Kim, Waukesha Bearings
Published in POWER magazine, March 2015

For one of its power generation customers in Scandinavia, Doosan Škoda Power engineered a 46 MW steam turbine as part of a combined cycle system for generation of electricity as well as heat recovery. During the initial commissioning, the turbine experienced rotor instability that prevented the drive train from operating at full load. High subsynchronous vibrations forced a trip in turbine operation at just 27 MW versus the rated 46 MW.

Changes to the bearing clearances and configurations mitigated the vibrations but were not able to eliminate them completely. Doosan Škoda Power decided to contact Bearings Plus, a Waukesha Bearings business, for a damper solution.

Learn how ISFD technology maximized the damping ratio and eliminated the subsynchronous vibrations spikes in the March 2015 issue of POWER magazine or online at www.powermag.com.

ISFD Paper Presented at ASME Turbo Expo

Waukesha Bearings, a global leader in the design and manufacture of oil- and process-lubricated engineered bearings, is proud to offer the presentation of the integral squeeze film damper (ISFD) 8 – 10 a.m. June 19, at the American Society of Mechanical Engineers (ASME) Turbo Expo in Düsseldorf, Germany.

The presentation is based on a paper that presents experimental tests and analytical results focused on stabilizing a 46 MW 6,230kg utility steam turbine experiencing subsynchronous rotordynamic instability. The paper, coauthored by Dr. Jong Kim, Sr. Principal Engineer of Waukesha Bearings, and several other ASME colleagues, advances an integral squeeze film damper (ISFD) solution which was implemented to resolve the subsynchronous vibration and allow full-load and full-speed operation of the machine.

View more information about the ISFD bearing system 

Dr. Jong Kim is Senior Principal Engineer for Waukesha Bearings. Joining KMC/BPI in 2001, he possesses extensive experience in rotordynamic analyses and bearing failure analyses. A former mechanical engineering teacher at Korea Maritime University for 10 years, Dr. Jong Kim received a BS degree (Mechanical Engineering, 1985) from Busan National University, and an MS degree (Mechanical Engineering, 1987) and a PhD (Mechanical Engineering, 1991) from KAIST (Korea Advanced Institute of Science and Technology). He has authored and coauthored several technical papers and holds patents on bearings and dampers.

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