In situ runout identification in active magnetic bearing system by extended influence coefficient method

1997 ◽  
Vol 2 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Cheol-Soon Kim ◽  
Chong-Won Lee
Keyword(s):  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Influence Coefficient ◽  
Influence Coefficient Method ◽  
Coefficient Method ◽  
Bearing System

A Method to Select Weights in Online Dynamic Balance Technology Based on Rotor-Active Magnetic Bearing System

2017 ◽  
Author(s):  
Yan Xunshi ◽  
Zhao Jingjing ◽  
Sun Zhe ◽  
Shi Zhengang
Keyword(s):  
Dynamic Balance ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Influence Coefficient ◽  
Rotating Speed ◽  
Balance Weight ◽  
Influence Coefficient Method ◽  
Short Time ◽  
Coefficient Method ◽  
Bearing System

Online dynamic balance technology is the key to rotor-active magnetic bearing system, which helps the rotating speed of the system surpass the critical speed. Usually, balance weight and angle are calculated by influence coefficient method. However, how to decompose the weight and angle into sub-weights fixed in the balance holes is troublesome, and determined manually by trial and error, which is always time-consuming. In this paper, a new hierarchical and automatic method is proposed to find the optimized solution to select proper sub-weights in a short time, which limits to a pre-defined error. The algorithm focuses on reducing the move of sub-weights and addition of new sub-weights. Experiments show our algorithm perform effective and efficient.

scholarly journals Active Control for Multinode Unbalanced Vibration of Flexible Spindle Rotor System with Active Magnetic Bearing

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaoli Qiao ◽  
Guojun Hu
Keyword(s):  
High Speed ◽  
Control Method ◽  
Magnetic Bearing ◽  
Rotor System ◽  
Active Magnetic Bearing ◽  
Influence Coefficient ◽  
Control Effect ◽  
High Speed Cutting ◽  
Influence Coefficient Method ◽  
Cutting Processes

The unbalanced vibration of the spindle rotor system in high-speed cutting processes not only seriously affects the surface quality of the machined products, but also greatly reduces the service life of the electric spindle. However, since the unbalanced vibration is often distributed on different node positions, the multinode unbalanced vibration greatly exacerbates the difficulty of vibration control. Based on the traditional influence coefficient method for controlling the vibration of a flexible rotor, the optimal influence coefficient control method with weights for multinode unbalanced vibration of flexible electric spindle rotors is proposed. The unbalanced vibration of all nodes on the whole spindle rotor is used as the control objective function to achieve optimal control. The simulation results show that the method has an obvious control effect on multinode unbalanced vibration.

In-Situ Identification of Active Magnetic Bearing System Using Directional Frequency Response Functions

1996 ◽  
Vol 118 (3) ◽  
pp. 586-592 ◽  
Author(s):  
Chong-Won Lee ◽  
Young-Ho Ha ◽  
Chee-Young Joh ◽  
Cheol-Soon Kim
Keyword(s):  
Frequency Response ◽  
Frequency Response Function ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Modal Testing ◽  
Modal Parameters ◽  
Response Functions ◽  
Frequency Responses ◽  
Bearing System

Complex modal testing is employed to obtain the directional frequency responses of a four-axis active magnetic bearing system. In the test, magnetic bearings are used as exciters while the system is in operation. The directional frequency response estimates are then used to effectively identify the parameters of the active magnetic bearing system. Experimental results show that the directional frequency response function, which is properly defined in the complex domain, is a powerful tool for identification of bearing as well as modal parameters of the system.

Influence Coefficients Obtained by Hammer Beat Permit Significant Time Savings When Balancing Simple Flexible Rotors

1999 ◽  
Author(s):  
D. Wiese ◽  
M. Breitwieser
Keyword(s):  
Influence Coefficient ◽  
Significant Time ◽  
Flexible Rotors ◽  
Influence Coefficients ◽  
Flexible Roll ◽  
Influence Coefficient Method ◽  
Time Savings ◽  
Positive Results ◽  
Coefficient Method

Abstract The following paper presents a method for balancing simple flexible rotors with the help of influence coefficients obtained by hammer beat. The method permits time savings of approx. 50% compared to the conventional influence coefficient method. Initial positive results obtained on a flexible roll are also presented.

scholarly journals Development and Experimental Validation of Auxiliary Rolling Bearing Models for Active Magnetic Bearings (AMBs) Applications

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Anna Tangredi ◽  
Enrico Meli ◽  
Andrea Rindi ◽  
Alessandro Ridolfi ◽  
Pierluca D’Adamio ◽  
...  
Keyword(s):  
Load Capacity ◽  
Critical Phenomenon ◽  
Magnetic Bearing ◽  
Design Tool ◽  
Magnetic Bearings ◽  
Active Magnetic Bearing ◽  
Active Magnetic Bearings ◽  
Short Period ◽  
Auxiliary Bearing ◽  
Bearing System

Nowadays, the search for increasing performances in turbomachinery applications has led to a growing utilization of active magnetic bearings (AMBs), which can bring a series of advantages thanks to their features: AMBs allow the machine components to reach higher peripheral speeds; in fact there are no wear and lubrication problems as the contact between bearing surfaces is absent. Furthermore, AMBs characteristic parameters can be controlled via software, optimizing machine dynamics performances. However, active magnetic bearings present some peculiarities, as they have lower load capacity than the most commonly used rolling and hydrodynamic bearings, and they need an energy source; for these reasons, in case of AMBs overload or breakdown, an auxiliary bearing system is required to support the rotor during such landing events. During the turbomachine design process, it is fundamental to appropriately choose the auxiliary bearing type and characteristics, because such components have to resist to the rotor impact; so, a supporting design tool based on accurate and efficient models of auxiliary bearings is very useful for the design integration of the Active Magnetic Bearing System into the machine. This paper presents an innovative model to accurately describe the mechanical behavior of a complete rotor-dynamic system composed of a rotor equipped with two auxiliary rolling bearings. The model, developed and experimentally validated in collaboration with Baker Hughes a GE company (providing the test case and the experimental data), is able to reproduce the key physical phenomena experimentally observed; in particular, the most critical phenomenon noted during repeated experimental combined landing tests is the rotor forward whirl, which occurs in case of high friction conditions and greatly influences the whole system behavior. In order to carefully study some special phenomena like rotor coast down on landing bearings (which requires long period of time to evolve and involves many bodies and degrees of freedom) or other particular events like impacts (which occur in a short period of time), a compromise between accuracy of the results and numerical efficiency has been pursued. Some of the elements of the proposed model have been previously introduced in literature; however the present work proposes some new features of interest. For example, the lateral and the axial models have been properly coupled in order to correctly reproduce the effects observed during the experimental tests and a very important system element, the landing bearing compliant suspension, has been properly modelled to more accurately describe its elastic and damping effects on the system. Furthermore, the model is also useful to characterize the frequencies related to the rotor forward whirl motion.

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