The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Magnetic bearings can support a floater (rotor) without mechanical contacts in rotating machinery systems. Since the rotors can be supported by magnetic bearings without mechanical contacts, some merits are expected. For example, (1) there are no friction and wear, (2) the system can be operated at higher rotational speeds than bearing systems with mechanical contacts, (3) vibration and noise can...
With the advantages of axial high utilization, small size and low power consumption, the bearing-less permanent-magnet synchronous motor (BPMSM) demonstrates the potential applications in space technology, machine tools, ultra-speed drives and so on. Generally, the magnetic circuit method (MCM) is applied to analyze the mathematical model of levitation force with rotor eccen-tricity[1-3]. However,...
Bearingless switched reluctance motor (SRM) has been a hot research topic for recent years. As the suspending force is important to bearingless SRM, optimization of suspending force for novel permanent magnet biased bearingless SRM is proposed in this paper. To get a better force performance, the permanent magnet's parameters (the physical dimensions) and some other parameters of the proposed motor...
By translationally moving a magnetic source above a conductive plate guideway both levitation and drag forces are created. Unfortunately, the electrodynamic drag force can be quite high [1]. Kratz studied a double Halbach array topology, such as shown in Fig 1 [1], and used a simple curve fitting approximation to model the forces. Kratz experimentally showed that a significant reduction in drag force...
Magnetic levitation system has been a topic of research since two decades wherein it has proved to be a promising technology in reducing the energy losses and acquiring high speed. This paper mainly focuses on non-contact position measurement of an object which is under the influence of electromagnetic field. The proposed technique describes utilization of a digital camera, in a non-linear plant,...
In the high speed industrial application, bearingless motor, which integrates advantages of magnetic bearing into motor, has received more and more attention.[1-2] In this paper, stiffness analysis for one novel bearingless SRM with bias permanent magnet is investigated. Fig.1 shows the basic structure and prototype motor. It's a radial suspending structure equipped with permanent magnet to provide...
Switched Reluctance Motor (SRM) has good performance under special environments such as fault tolerance, robustness, tolerance of high temperature or in intense temperature variations. In the meanwhile, SRM has a good feature as magnetic bearing due to the inherent magnetic attraction radial force between rotor and stator poles[1]. This radial force can suspend the rotor. The bearing-less SRM combines...
The hydroelectric generating set (HGS) is the machine that transform the water energy to power. The vertical structure is more common which is applied in large and medium-sized system. Because of great bulk, the rotating parts including generator's rotor, macroaxis, turbine runner and spiral case are great heavy. In addition, water flow impulsing the runner will produce a down force named axial hydro-thrust...
Improving accuracy is one of the most important research topics in many advanced industrial applications, such as microscopy, biomedical science and semiconductor lithography. On the one hand, to improve the accuracy requires improvement on the system precision, on the other hand, it requires improvement on the system vibration isolation capability. At present, active vibration isolation system composed...
Magnetic bearings (MBs) can be classified as active magnetic bearing (MB), hybrid MB and passive MB. Recently, MBs have been applied in high speed motor, magnetic suspension flywheel, artificial heart blood pump and so on. MBs have obtained extensive research interest [1-3]. Axial hybrid magnetic bearing (AHMB) has the advantages of small size, low power consumption, no friction, no abrasions, free...
MRI-based navigation and propulsion of millirobots is a new and promising approach for minimally invasive therapies. The strong central field inside the scanner, however, precludes torque-based control. Consequently, prior propulsion techniques have been limited to gradient-based pulling through fluid-filled body lumens. This paper introduces a technique for generating large impulsive forces that...
A two-degrees-of-freedom actively positioned consequent-pole bearingless motor with a wide magnetic gap of 8 mm and a gap factor (gap/rotor radius) of 0.2 is proposed. Experimental results of the magnetic suspension tests at a rotational speed up to 6000 r/min have been demonstrated. The axial and passive stiffnesses are sufficient for stable magnetic suspension while rotation. To improve the suspension...
This paper discusses the suspension force of consequent-pole permanent magnet (CPM) and surface-mounted permanent magnet (SPM) bearingless motors with two-independent three-phase concentrated windings for motor and magnetic suspension. Influence of spatial harmonics in the magneto-motive force (MMF) distribution caused by the concentrated winding on the suspension force profile is analytically investigated...
This paper presents the design and experimental validation of a magnetically suspended planar motor with integrated contactless energy transfer system. The translator of the planar motor embeds four iron-cored linear synchronous motors which magnetically suspend and propel the translator underneath a stationary checkerboard permanent magnet array. A contactless energy transfer system, by means of...
The Magnetically Levitated Solar Motor (MLSM) is a Solar-powered, the magnetically mounted electric motor consists of a square-shaped body rotor. This carries the solar cells and the windings. To each winding two solar cells are connected in parallel. The horizontally arranged rotor shaft carries the rotor body and a magnet at each end. At one end of the shaft a tip of the rotor is mounted. On one...
A levitation system, which is composed of a highly oriented pyrolytic graphite (HOPG) rotor and NdFeB permanent magnets, is proposed in this paper. The diamagnetic force between the HOPG rotor and the NdFeB magnets contributes to between the HOPG rotor and the NdFeB magnets contributes to the levitation and friction-free rotation of the rotor. The rotor is first designed as a disc with four blades...
This paper deals with the modeling and control of a magnetically levitated planar motor. The actuator considered has moving coils and stationary magnets. The principal objective is to develop a model which can be implemented in simulation. Therefore, the data obtained by a finite element method (FEM) are used to derive mathematical expressions of the force and torque produced by this motor. Moreover,...
A control method of adjusting the stiffness of suspension is proposed for magnetic suspension systems whose bias flux is provided by permanent magnets. In such magnetic suspension systems, zero-power control has often been applied. Since the zero-power magnetic suspension system behaves as if it has negative stiffness, it has been applied to vibration isolation system. However, the amplitude of negative...
This paper describes the design, modelling, fabrication and control of an attraction type electromagnetic lévitation prototype with single-axis control. The system is simulated using standard FEM packages and used in control system related investigations. The mathematical model of the system has also been derived. Experiments have also been carried out. Practically evaluated system parameters show...
The stirling convertor is a high efficient power generator, many kinds of heat source can be used in this technology with good suitability, high efficiency, simple structure and long life. As the important component of the stirling convertor, linear generator can adapt well with the stirling engine. The structure of the generator is cylinder type of moving permanent magnet, which is single-phase and...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.