Clearance compatibility and design principle of the single-structured hybrid gas-magnetic bearing
Industrial Lubrication and Tribology
ISSN: 0036-8792
Article publication date: 6 November 2023
Issue publication date: 22 November 2023
Abstract
Purpose
This paper aims to study the clearance compatibility of active magnetic bearing (AMB) and gas bearing (GB) to achieve a single-structured hybrid gas-magnetic bearing (HGMB), which uses a single bearing structure to realize both the functions of gas bearing and magnetic bearing.
Design/methodology/approach
Because the radial clearance size of the AMB is typically ten times larger than that of the GB, radial clearance compatibility of GB and AMB needs to maximize the radial clearance of GB by adjusting structural parameters. Parametric analysis of structural parameters of GB is explored. Furthermore, a general structural design principle based on static analysis, rotordynamic performance and system stability is established for the single-structured HGMB.
Findings
Load capacity is vastly reduced due to the enlarged radial clearance of the GB. A minimum clearance needs to be ensured by increasing the bearing diameter or width to compensate for the reduced load capacity, yet indirectly raising the bearing load. Increased bearing load is conducive to stability, yet it raises the risk of rotor abrasion. In addition, excessively large bearing diameter leads to system instability, and inappropriate bearing width affects critical speeds. A general structural design principle is established and the designed HGMB–rotor processes optimal performances.
Originality/value
A single-structured HGMB is proposed to address the urgent demand for high-speed, cryogenic turboexpanders with frequent starts/stops. This design applies a single-bearing structure to realize the characteristics of both GB and AMB, greatly simplifying the implementation, reducing air friction loss and raising critical speeds. This paper provides a fresh perspective on the development of cryogenic turboexpanders for hydrogen liquefaction. It theoretically validates the feasibility and provides a design guide for a single-structured HGMB system.
Keywords
Acknowledgements
The research leading to these results received funding from Fundamental Research Funds for the Central Universities under Grant No. FRF-TP-22-034A1.
Citation
Liu, Q., Wang, L. and Feng, M. (2023), "Clearance compatibility and design principle of the single-structured hybrid gas-magnetic bearing", Industrial Lubrication and Tribology, Vol. 75 No. 10, pp. 1219-1228. https://doi.org/10.1108/ILT-03-2023-0077
Publisher
:Emerald Publishing Limited
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