Integration of a Squeeze Film Damper in the Journal Bearing of a High-Speed Electric Motor

Abstract Squeeze film dampers have shown positive effects on the dynamic behavior of various types of rotating machinery. They are widely used in gas turbines of aerospace applications and have also been applied in many industrial machines, often as a measure of mitigating unexpectedly high vibration. In this paper, we show how a squeeze film damper can be integrated into a state-of-the-art journal bearing used in high-speed electric motors, and its effects on machine vibrations during operation. Our integration concept allows for on-site adaptation of squeeze film damper stiffness and for transmission of thrust forces in combined journal and thrust bearings. The test setup in a carefully controlled test bench with well-known operational characteristics is explained, and test run results with and without squeeze film damper and with otherwise identical journal bearings are compared, testing and confirming the applicability of squeeze film damper design formulae to our system. It is shown that a squeeze film damper is particularly well-suited for machines with a large operating speed range and can enable very low vibrations therein. For high-speed electric motors, this makes journal bearings with squeeze film dampers a valuable alternative to magnetic bearings, with reduced system costs and complexity.