Rotordynamic Analysis

Comprehensive System Analysis

Waukesha Bearings utilizes comprehensive rotordynamic analysis to validate original builds for OEMs and to diagnose problems and propose the right solutions for end users.

Along with the rotor, the bearings and seals are the most influential components in rotating equipment vibrations. Therefore, the accuracy of a rotordynamic analysis relies on the analyses of the bearing and seal characteristics.

Compressor frame
Example of rotor model for rotordynamic analysis

Accuracy, Reliability

As a global leader in the engineering and manufacturing of bearings and seals, Waukesha Bearings has the most reliable and accurate tools to perform those analyses.

Our industry-leading analytical tools include transfer matrix, polynomial transfer matrix and finite element–based rotordynamic analysis tools.

The accuracy of our analyses and predictions allows us to optimize the dynamic characteristics of bearings and seals for individual operating systems to ensure optimal performance.

Torsional, Axial and Lateral Analysis

Torsional, axial and lateral vibrations can each affect the efficiency and reliability of rotating equipment. Torsional vibration is an angular vibration, or twisting, of the shaft. Axial vibration occurs along the axis of rotation, while lateral vibration occurs perpendicular to the axis – side to side or up and down or both.

Upon receipt of the relevant information, our engineers build a rotor model and analyze the bearings and seals using proprietary codes. The customer receives a comprehensive report of the findings, based on the type and scope of analysis performed.

Example of lateral rotordynamic analysis plot

Lateral Rotordynamic Analysis

  • Undamped critical speed (UCS) analysis
  • Damped critical speed analysis
  • Eigenvalue analysis (critical speeds, mode shapes)
  • Unbalance response analysis
  • API stability analysis (level I and II)
  • Bearing and seal optimization
  • ISFD optimization, if needed
  • Brush seal contact–induced stability and unbalance analysis, if needed
Example of torsional rotordynamic analysis plot

Torsional Rotordynamic Analysis

  • Torsional natural frequencies
  • Eigenvalue analysis (critical speeds, mode shapes)
  • Damped torque or stress response analysis, if needed
  • Transient analysis for start-up or short circuit analysis for motor or generator trains
  • Transient torsional stress analysis on critical points (e.g., coupling, rotor)

Case Study

Achieving Full Power Output

For a power generation customer in Scandinavia, Doosan Škoda Power engineered a 46 MW steam turbine as part of a combined cycle system. When high subsynchronous vibrations forced a trip in turbine operation at just 27 MW versus the rated 46 MW, a rotordynamic assessment confirmed the cause of the vibrations and informed an effective solution.

Read the Case Study >

Steam turbine for power generation

Leading Vibration Solutions

Flexure Pivot tilt pad journal bearing

Flexure Pivot® Journal Bearings

Flexure Pivot tilt pad journal bearings achieve high stability while eliminating pivot wear, high contact stresses and pad flutter than can affect conventional tilt pad designs.

ISFD technology

Integral Squeeze Film Damper

ISFD® technology provides precise stiffness and damping to meet rotordynamic requirements, and is suitable for both new and retrofit installations.

Maxalign tilting pad journal bearing with hydrostatic lift and 'Directed Lubrication'

Maxalign® Bearings

Optimized for large-frame turbomachinery, Maxalign bearings use a patented ball and socket pivot support to provide superior stiffness and meet the demand for misalignment capability.

Waukesha Bearings Advantage

  • The most comprehensive analytical capabilities in the industry
  • Wide and deep knowledge of bearings and seals
  • Accurate in-house tools for bearing and seal analysis
  • Accurate rotordynamic analysis and predictions
  • Proven engineered solutions
  • Continuous research and development of new technologies

Typical Applications