Active Balancing of a High Speed Rotor in Magnetic Bearings

1992 ◽  
pp. 19-26 ◽  
Author(s):  
C. R. Knospe ◽  
R. R. Humphris ◽  
E. H. Maslen ◽  
P. E. Allaire
Keyword(s):  
High Speed ◽  
Magnetic Bearings ◽  
Active Balancing

A Magnetic Drive Actuator for Micro Electrical Discharge Machining

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.

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

2000 ◽  
Vol 123 (3) ◽  
pp. 464-472 ◽  
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.

Design and analysis of a high speed double-sided axial flux permanent magnet motor suspended vertically by magnetic bearings

2020 ◽  
pp. 1-15
Author(s):  
Ömer Faruk Güney ◽  
Ahmet Çelik ◽  
Ahmet Fevzi Bozkurt ◽  
Kadir Erkan
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
Permanent Magnets ◽  
Mechanical Analysis ◽  
Magnetic Bearings ◽  
Permanent Magnet Motor ◽  
Axial Flux ◽  
Element Analysis ◽  
Shaft System ◽  
Rotor Disk

This paper presents the electromagnetic and mechanical analysis of an axial flux permanent magnet (AFPM) motor for high speed (12000 rpm) rotor which is vertically suspended by magnetic bearings. In the analysis, a prototype AFPM motor with a double-sided rotor and a coreless stator between the rotors are considered. Firstly, electromagnetic analysis of the motor is carried out by using magnetic equivalent circuit method. Then, the rotor disk thickness is determined based on a rotor axial displacement due to the attractive force between the permanent magnets placed on opposite rotor disks. Hereafter, an analytical solution is carried out to determine the natural frequencies of the rotor-shaft system. Finally, 3D finite element analysis (FEA) is carried out to verify the analytical results and some experimental results are given to verify the analytical and numerical results and prove the stable high-speed operation.

Vibrations monitoring of high speed spindle with active magnetic bearings in presence of defects

2015 ◽  
Vol 49 (2) ◽  
pp. 207-221 ◽  
Author(s):  
Amel Bouaziz ◽  
Slim Bouaziz ◽  
Taissir Hentati ◽  
Jean Yves Cholley ◽  
Mohamed Haddar
Keyword(s):  
High Speed ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings
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