Dynamic characteristics of hybrid foil-magnetic bearings (HFMBs) concerning eccentricity effect

2016 ◽  
Vol 52 (1-2) ◽  
pp. 271-279 ◽  
Author(s):  
Baisong Yang ◽  
Haipeng Geng ◽  
Yanhua Sun ◽  
Lie Yu
Keyword(s):  
Dynamic Characteristics ◽  
Magnetic Bearings ◽  
Eccentricity Effect

scholarly journals Dynamic characteristics of triaxial active control magnetic bearing with asymmetric structure

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 9-13 ◽  
Author(s):  
Atsushi Nakajima ◽  
Katsuhiro Hirata ◽  
Noboru Niguchi ◽  
Masayuki Kato
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Active Control ◽  
Dynamic Characteristics ◽  
Negative Pressure ◽  
Axial Direction ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Asymmetric Structure ◽  
Element Analysis

Abstract Supporting forces of magnetic bearings are lower than those of mechanical bearings. In order to solve these problems, this paper proposes a new three-axis active control magnetic bearing (3-axis AMB) with an asymmetric structure where its rotor is attracted only in one axial direction due to a negative pressure of fluid. Our proposed 3-axis AMB can generate a large suspension force in one axial direction due to the asymmetric structure. The performances of our proposed 3-axis AMB are computed through 3-D finite element analysis.

Effects of the Magnetic Damper Locations on Dynamic Characteristics of the Active Magnetic Bearing System in Manufacturing Engineering

2012 ◽  
Vol 252 ◽  
pp. 51-55
Author(s):  
Zhen Yu Xie ◽  
Hong Kai Zhou ◽  
Xiao Wang
Keyword(s):  
Dynamic Characteristics ◽  
High Speed ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Active Magnetic Bearing ◽  
Active Magnetic Bearings ◽  
Actual Operation ◽  
And Control ◽  
System Operating ◽  
Bearing System

The magnetic damper was introduced into the high speed rotating machinery to restrain the vibration of the rotor supported by active magnetic bearings. The experimental setup, which was made up of one rotor, two radial active magnetic bearings, one axial active magnetic bearing, one magnetic damper and control system, was built to investigate the effects of the magnetic damper locations on dynamic characteristics of the system by theoretical analysis, experimental modal analysis and actual operation of the system. The results show that the vibration of the active magnetic bearing system operating at the modal frequency can be reduced more effectively if the magnetic damper is located far from the nodes of the corresponding mode shape.

The Influence of Thermal Deformation on the Dynamic Characteristics of AMB Rotor of HTR-PM Helium Blower

2018 ◽  
Author(s):  
Guowei Du ◽  
Jinpeng Yu ◽  
Hong Wang ◽  
Lei Zhao
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Dynamic Characteristics ◽  
Electromagnetic Force ◽  
Thermal Deformation ◽  
Magnetic Bearings ◽  
Stable Operation ◽  
Active Magnetic Bearings ◽  
Rotating Shaft ◽  
Motor Cooling

Helium blower is the core component of high temperature gas cooled reactor, which rotor is supported by active magnetic bearings (AMBs). The special advantage of AMB is that there is no contact between bearing and rotor, and this permits operation with small friction, long service life, no lubrication system, and no pollution to the helium environment. [1–3] Helium blower rotor is mainly composed of rotating shaft, impeller, motor, cooling blower and so on, which runs in an uneven temperature field that the impeller runs in a helium chamber of 250 degrees centigrade, and the motor housing’s outer surface temperature is 65 degrees centigrade. The temperature rises from standstill to stable operation will cause the thermal deformation of rotor and bearing, leading to the change of gap between rotor and bearing, which will lead to the change of electromagnetic force of AMB. The electromagnetic force determines the bearing stiffness and bearing damping of the AMB, so the change of temperature is the most important to the stiffness and damping of the AMB, which can affect the dynamic characteristics of the rotor. Through finite element method (FEM) to calculate the temperature field and displacement field of helium blower, the change of the gap of AMB and rotor is calculated. The rotor radial displacement orbits are obtained through numerical simulation, which are affected by thermal deformation. Finally, the results of numerical simulation are verified by experiments. The simulation and experiments both show that temperature rise can increase the vibration amplitude of rotor, so the influence of thermal deformation should be considered when designing the active magnetic bearings.

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