Design of High-Speed Rotor Systems with Gas-Magnetic Bearings

Health monitoring is of critical importance in maintaining the integrity of high-speed rotating machinery. In this paper, a health monitoring strategy based upon the acquisition and analysis of vibration measurements is described and evaluated. A common technique in this regard is to track changes in the synchronous vibration due to imbalance. However, such an approach must consider the controller strategy used with the magnetic bearings. Herein, a simulation model is developed that consists of a flywheel system supported by magnetic bearings, which are controlled using an adaptive strategy that suppresses synchronous vibration. The interaction between the rotor vibration and the controller responses are evaluated in order to provide insight into indicators of crack initiation and growth. The results and conclusions are also validated using an experimental test rig. Some insights and guidelines as to appropriate strategies for crack detection in rotor systems interacting with active bearing controllers is presented and discussed.

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Unbalance Response Analysis on the High Speed Flywheel Motor Supported by Active Magnetic Bearings

2020 IEEE 4th Conference on Energy Internet and Energy System Integration (EI2) ◽

10.1109/ei250167.2020.9346804 ◽

2020 ◽

Author(s):

Dongxu Hu ◽

Xingjian Dai ◽

Zhehui Niu ◽

Yang Xu ◽

Haisheng Chen

Keyword(s):

High Speed ◽

Magnetic Bearings ◽

Response Analysis ◽

Active Magnetic Bearings ◽

Unbalance Response

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A Magnetic Drive Actuator for Micro Electrical Discharge Machining

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.591-593.303 ◽

2012 ◽

Vol 591-593 ◽

pp. 303-306

Author(s):

Xiao You Zhang ◽

Akio Kifuji ◽

Dong Jue He

Keyword(s):

Electrical Discharge ◽

High Speed ◽

Degrees Of Freedom ◽

Electrical Discharge Machining ◽

Magnetic Coupling ◽

Magnetic Bearings ◽

Coupling Mechanism ◽

Micro Electrical Discharge Machining ◽

Long Stroke ◽

Magnetic Drive

Electrical discharge machining has the capability of machining all conductive materials regardless of hardness, and has the ability to deal with complex shapes. However, the speed and accuracy of conventional EDM are limited by probability and efficiency of the electrical discharges. This paper describes a three degrees of freedom (3-DOF) controlled, wide-bandwidth, high-precision, long-stroke magnetic drive actuator. The actuator can be attached to conventional electrical discharge machines to realize a high-speed and high-accuracy EDM. The actuator primarily consists of thrust and radial magnetic bearings, thrust and radial air bearings and a magnetic coupling mechanism. By using the thrust and radial magnetic bearings, the translational motions of the spindle can be controlled. The magnetic drive actuator possesses a positioning resolution of the order of micrometer, a bandwidth greater than 100Hz and a positioning stroke of 2mm.

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Active Balancing of a High Speed Rotor in Magnetic Bearings

Rotordynamics ’92 ◽

10.1007/978-1-4471-1979-1_3 ◽

1992 ◽

pp. 19-26 ◽

Cited By ~ 3

Author(s):

C. R. Knospe ◽

R. R. Humphris ◽

E. H. Maslen ◽

P. E. Allaire

Keyword(s):

High Speed ◽

Magnetic Bearings ◽

Active Balancing

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Dynamics of High-Speed Precision Geared Rotor Systems

MATEC Web of Conferences ◽

10.1051/matecconf/20141303008 ◽

2014 ◽

Vol 13 ◽

pp. 03008

Author(s):

Teik C. Lim

Keyword(s):

High Speed ◽

Rotor Systems

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Tip Clearance Actuation With Magnetic Bearings for High-Speed Compressor Stall Control

Journal of Turbomachinery ◽

10.1115/1.1370163 ◽

2000 ◽

Vol 123 (3) ◽

pp. 464-472 ◽

Cited By ~ 12

Author(s):

Z. S. Spakovszky ◽

J. D. Paduano ◽

R. Larsonneur ◽

A. Traxler ◽

M. M. Bright

Keyword(s):

High Speed ◽

Design Procedure ◽

Magnetic Bearing ◽

Rotating Stall ◽

Tip Clearance ◽

Magnetic Bearings ◽

Test Facility ◽

Control Analysis ◽

Servo Actuator ◽

Stall Control

Magnetic bearings are widely used as active suspension devices in rotating machinery, mainly for active vibration control purposes. The concept of active tip-clearance control suggests a new application of magnetic bearings as servo-actuators to stabilize rotating stall in axial compressors. This paper presents a first-of-a-kind feasibility study of an active stall control experiment with a magnetic bearing servo-actuator in the NASA Glenn high-speed single-stage compressor test facility. Together with CFD and experimental data a two-dimensional, incompressible compressor stability model was used in a stochastic estimation and control analysis to determine the required magnetic bearing performance for compressor stall control. The resulting requirements introduced new challenges to the magnetic bearing actuator design. A magnetic bearing servo-actuator was designed that fulfilled the performance specifications. Control laws were then developed to stabilize the compressor shaft. In a second control loop, a constant gain controller was implemented to stabilize rotating stall. A detailed closed loop simulation at 100 percent corrected design speed resulted in a 2.3 percent reduction of stalling mass flow, which is comparable to results obtained in the same compressor by Weigl et al. (1998. ASME J. Turbomach. 120, 625–636) using unsteady air injection. The design and simulation results presented here establish the viability of magnetic bearings for stall control in aero-engine high-speed compressors. Furthermore, the paper outlines a general design procedure to develop magnetic bearing servo-actuators for high-speed turbomachinery.

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