scholarly journals Technological assurance of reliability of centrifugal pumps for pumping biomass processing products based on adaptive dampers

2021 ◽  
Vol 2094 (5) ◽  
pp. 052047
Author(s):  
O A Kolenchukov ◽  
E A Kozhukhov ◽  
E A Petrovsky ◽  
V V Bukhtoyarov ◽  
V A Kachaeva
Keyword(s):  
Permanent Magnets ◽  
Hysteresis Loops ◽  
Magnetic Suspension ◽  
Magnetic Bearings ◽  
Optimal Size ◽  
Centrifugal Pumps ◽  
Biomass Processing ◽  
Technological Advances ◽  
The Stability ◽  
Stiffness And Damping

Abstract In almost every mechanical system, moving mechanisms slide over stationary parts, creating friction and, as a result, unwanted energy losses. In engineering, sliding or rolling bearings are most often used as supports. However, any system can benefit from a greater reduction in friction between components. As will be shown in this article, the stability problem can be solved by blocking vibrations in the radial direction. The latest technological advances in the field of manufacturing magnetic materials make it possible to integrate magnetic bearings with permanent magnetization (hereinafter - MBPM) into a larger number of mechanical systems. This blocking of radial movement is carried out without the use of a mechanical sliding bearing, chosen for its simplicity and ease of integration. To facilitate the integration of the MBPM into the overall system of the device, it is important to know the mechanical properties of magnetic bearings, namely stiffness and damping, as well as the performance characteristics and limits of their operation. This article examines the possibility of using an adaptive damper in centrifugal pumps to ensure the technological reliability of the equipment. Alternating permanent magnets in the direction of their movement is the most optimal option, leading to large and smooth hysteresis loops of force - displacement. The proposed arrangement of magnets ensures the adaptability of the device with the determination of its optimal size, and also takes into account the edge and surface effects in the design of the damper. In addition, the article discusses theoretical and technical issues of levitation - free floating of bodies. Magnetic suspension can be used to study only those processes where mechanical connections are undesirable. The use of magnetic suspension for balancing centrifugal pumps during transportation of biomass processing products, supports of mixing devices in reactors in biomass processing reactors and other machine components opens up wide opportunities.

scholarly journals Permanent magnet thrust bearings for flywheel energy storage systems: Analytical, numerical, and experimental comparisons

2019 ◽  
Vol 233 (15) ◽  
pp. 5280-5293
Author(s):  
Nikolaj A Dagnaes-Hansen ◽  
Ilmar F Santos
Keyword(s):  
Energy Storage ◽  
Permanent Magnet ◽  
Storage Systems ◽  
Magnetic Suspension ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings ◽  
Flywheel Energy Storage ◽  
Energy Storage Systems ◽  
Thrust Bearings ◽  
Stiffness And Damping

A new type of flywheel energy storage system uses a magnetic suspension where the axial load is provided solely by permanent magnets, whereas active magnetic bearings are only used for radial stabilization. This means that the permanent magnet bearing must provide all the axial damping. Furthermore, it must have as low a negative radial stiffness as possible to reduce the workload on the radial active magnetic bearings. Many different mathematical models for determining force, stiffness, and damping of permanent magnet bearings are available in the literature. This work will further develop the most applicable analytical and numerical methods in order to make them directly implementable for designing permanent magnet thrust bearings for flywheel energy storage systems. The outcome is a fast and efficient method for determining force, stiffness, and damping when the bearing setup contains magnetic materials with relative permeability higher than one as well as when it does not. The developed method is validated against numerical and experimental results with good agreement.

Design of a combined self-stabilizing electrodynamic passive magnetic bearing support for the automotive turbocharger rotor

2020 ◽  
pp. 107754632093348
Author(s):  
Tomasz Szolc ◽  
Krzysztof Falkowski ◽  
Paulina Kurnyta-Mazurek
Keyword(s):  
Dynamic Interaction ◽  
Magnetic Bearing ◽  
Magnetic Suspension ◽  
Magnetic Bearings ◽  
Main Attention ◽  
Rotor Shaft ◽  
Hurwitz Stability ◽  
Damping Characteristics ◽  
3D Finite Element Method ◽  
Stiffness And Damping

The purpose of this study is to create a concept for what would be a structurally simple and operationally robust support for the automotive turbocharger rotor in electrodynamic passive magnetic bearings. Because this kind of magnetic suspension—in its fundamental version—is dynamically unstable, to avoid the disadvantages contained therein, what is being proposed is the addition of external damping through the employment of the newly designed combined self-stabilizing electrodynamic passive magnetic bearing. The electromagnetic stiffness and damping characteristics of combined electrodynamic passive magnetic bearings have been determined for various shaft rotational speeds by means of the advanced 3D finite element method. In this study, a dynamic interaction between the turbocharger rotor shaft and the passive magnetic suspension is proposed as a support for both the fundamental electrodynamic passive magnetic bearings and the suggested combined self-stabilizing passive magnetic bearings. Here, the main attention is focused on the asymptotic stability of both the rotor shaft suspension variants. The additional damping magnitudes required to stabilize the most sensitive lateral eigenmodes of the object under consideration have been determined by means of the Routh–Hurwitz stability criterion.

The Robust Control of Magnetic Bearings for Rotating Machinery

2006 ◽  
Vol 113 ◽  
pp. 125-130 ◽  
Author(s):  
Zdzisław Gosiewski ◽  
Arkadiusz Mystkowski
Keyword(s):  
Robust Control ◽  
Controller Design ◽  
Magnetic Suspension ◽  
Magnetic Bearings ◽  
Weight Functions ◽  
H2 Control ◽  
Uncertainty Model ◽  
Energy Limitation ◽  
And Performance ◽  
The Stability

The fast progress in the applications of active magnetic suspension systems needs to apply the modern control theory. This paper deals with H∞ and H2 control of rigid rotor movement, which is supported in magnetic bearings. The robust control of magnetic bearings is investigated analytically. The nominal model of active magnetic suspension of rotor and the uncertainty model were derived. The standard PID control and robust control are compared and performance of nominal feedback configuration with weights is presented. We propose a robust control with a multi-objective controller to achieve good robust stability when the model of a plant is uncertain. The behavior of multiplicative uncertainty of magnetic suspension system is shown. The aim of optimal robust control is to improve the magnetic suspension taking into account the energy limitation (i.e., to avoid the saturation of actuators). The H2 performance and H∞ performance depend on a proper selection of weighting functions. So a very important step in the controller design process is to choose the appropriate weight functions: We, Wu, Wd. The influence of noise is limited by weight functions. We also put limits on input and output signals. The stability of a system with disturbance interaction is discussed. The simulations of a well-posed and internally stable magnetic system are presented. The success of the robust control is demonstrated through results of numerical simulations.

Magnetic suspension mechanism using rotary permanent magnets

2020 ◽  
Vol 64 (1-4) ◽  
pp. 977-983
Author(s):  
Koichi Oka ◽  
Kentaro Yamamoto ◽  
Akinori Harada
Keyword(s):  
Permanent Magnets ◽  
Suspension System ◽  
Magnetic Suspension ◽  
Horizontal Force ◽  
Mechanical Contact ◽  
New Type ◽  
Magnetic Suspension System

This paper proposes a new type of noncontact magnetic suspension system using two permanent magnets driven by rotary actuators. The paper aims to explain the proposed concept, configuration of the suspension system, and basic analyses for feasibility by FEM analyses. Two bar-shaped permanent magnets are installed as they are driven by rotary actuators independently. Attractive forces of two magnets act on the iron ball which is located under the magnets. Control of the angles of two magnets can suspend the iron ball stably without mechanical contact and changes the position of the ball. FEM analyses have been carried out for the arrangement of two permanent magnets and forces are simulated for noncontact suspension. Hence, successfully the required enough force against the gravity of the iron ball can be generated and controlled. Control of the horizontal force is also confirmed by the rotation of the permanent magnets.

A HYBRID MODEL ON HYSTERESIS LOOP AND COERCIVITY IN NANOSTRUCTURED PERMANENT MAGNETS

2006 ◽  
Vol 05 (04n05) ◽  
pp. 627-631 ◽  
Author(s):  
M. J. SUN ◽  
G. P. ZHAO ◽  
J. LIANG ◽  
G. ZHOU ◽  
H. S. LIM ◽  
...  
Keyword(s):  
Thin Films ◽  
Domain Wall ◽  
Grain Boundary ◽  
Magnetic Moment ◽  
Permanent Magnets ◽  
Hysteresis Loops ◽  
Bulk Materials ◽  
Rotational Model ◽  
Moment Distribution ◽  
Coercivity Mechanism

A simplified micromagnetic model has been proposed to calculate the hysteresis loops of nanostructured permanent magnets for various configurations, including thin films, exchange-coupled double-layer systems and bulk materials. The reversal part of the hysteresis is based on the Stoner–Wohlfarth coherent rotational model and the coercivity mechanism is due mainly to the motion of the transition region (a domain wall like magnetic moment distribution in the grain boundary). The elements of nucleation and pinning models are also incorporated.

scholarly journals Developing a reference material set for the magnetic properties of NdFeB alloy-based hard magnetic materials

2019 ◽  
Vol 15 (1) ◽  
pp. 21-27
Author(s):  
E. A. Volegova ◽  
T. I. Maslova ◽  
V. O. Vas’kovskiy ◽  
A. S. Volegov
Keyword(s):  
Magnetic Properties ◽  
Magnetic Materials ◽  
Permanent Magnets ◽  
Magnetic Loss ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Magnetic Hysteresis Loop ◽  
Magnetic Characteristics ◽  
Hard Magnetic Materials ◽  
Certified Values

Introduction The introduction indicates the need for the use of permanent magnets in various technology fields. The necessity of measuring the limit magnetic hysteresis loop for the correct calculation of magnetic system parameters is considered. The main sources of error when measuring boundary hysteresis loops are given. The practical impossibility of verifying blocks of magnetic measuring systems element-by-element is noted. This paper is devoted to the development of reference materials (RMs) for the magnetic properties of hard magnetic materials based on Nd2Fe14B, a highly anisotropic intermetallic compound.Materials and measuring methods Nd-Fe-B permanent magnets were selected as the material for developing the RMs. RM certified values were established using a CYCLE‑3 apparatus included in the GET 198‑2017 State Primary Measurement Standard for units of magnetic loss power, magnetic induction of constant magnetic field in a range from 0.1 to 2.5 T and magnetic flux in a range from 1·10–5 to 3·10–2 Wb.Results and its discussion Based on the experimentally obtained boundary hysteresis loops, the magnetic characteristics were evaluated, the interval of permitted certified values was set, the measurement result uncertainty of certified values was estimated, the RM validity period was established and the first RM batch was released.Conclusion On the basis of conducted studies, the RM type for magnetic properties of NdFeB alloy-based hard magnetic materials was approved (MS NdFeB set). The developed RM set was registered under the numbers GSO 11059–2018 / GSO 11062–2018 in the State RM Register of the Russian Federation.

Thermal Stability of Magnetic Properties in Dehydrogenated Triarylmethane Resins

1989 ◽  
Vol 173 ◽  
Author(s):  
Michiya Otani ◽  
Sugio Otani
Keyword(s):  
Thermal Stability ◽  
Magnetic Properties ◽  
Magnetic Property ◽  
Room Temperature ◽  
Permanent Magnets ◽  
Elevated Temperatures ◽  
Mechanical Response ◽  
The Stability ◽  
Thermal Stability Of

ABSTRACTThe stability of the magnetic properties of dehydrogenated triaryl-methane resins was investigated both at room temperature and at elevated temperatures. A magnetic property different from that reported in a previous paper was found in the course of studying the reproducibility of synthesis. This new property was examined through a mechanical response of the resins to a set of permanent magnets.

A Variable Viscosity Approach for the Analysis of Steady State and Dynamic Characteristics of Two-Lobe Journal Bearing With TiO2 Based Nanolubricant

2017 ◽  
Author(s):  
Ashutosh Kumar ◽  
Sashindra Kumar Kakoty
Keyword(s):  
Steady State ◽  
Dynamic Characteristics ◽  
Journal Bearing ◽  
Volume Fraction ◽  
Variable Viscosity ◽  
Flow Coefficient ◽  
Viscosity Model ◽  
Nano Lubricant ◽  
The Stability ◽  
Stiffness And Damping

Steady-state and dynamic characteristics of two-lobe journal bearing, operating on TiO2 based Nano-lubricant has been obtained. The effective viscosity is obtained by using Krieger-Dougherty viscosity model for a given volume fraction of nanoparticle in the base fluid. Various bearing performance characteristics are then obtained by solving modified Reynolds equation for variable viscosity model and couple stress model. The stiffness and damping coefficients are also determined for various values of the volume fraction of the nanoparticle in the nanofluid. Results reveal that load carrying capacity and flow coefficient increase whereas friction variable decreases without affecting the stability condition of two-lobe journal bearing operating on TiO2 based nanolubricant. On the other hand attitude angle and dynamic coefficients remains constant for all the values of volume fraction of nanoparticle.

Stability and Response of Rotors Supported on Active Magnetic Bearings

1993 ◽  
Author(s):  
K. Ramesh ◽  
R. G. Kirk
Keyword(s):  
Finite Element ◽  
Stability Analysis ◽  
Transfer Matrix ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings ◽  
Finite Element Program ◽  
Element Program ◽  
Matrix Codes ◽  
The Stability

Abstract A PC-based program has been developed which is capable of performing stability analysis and response calculations of rotor-bearing systems. The paper discusses the modeling of rotors supported on active magnetic bearings (AMB) and highlights the advantages in the modeling using the finite element method, over the transfer matrix method. An 8-stage centrifugal compressor supported on AMB was chosen for the case study. The results for the stability analysis, obtained using the finite element program was compared with those obtained by the well established transfer matrix codes. The results of unbalance response, including the effects of sensor non collocation are presented and this demonstrates how an AMB supported rotor can experience a synchronous instability for selected sensor locations and balance distributions.

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