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A global approach for the study of forces developed by a tubular linear moving magnet actuator for a low speed and high force application is described. We used here an easy analytical approach made with the Ampere's law to give the field distribution done by permanent magnets in the airgap. In order to calculate the effort developed by the moving part we used the Laplace force which takes into account...
This paper concerns permanent magnet and coil geometries of coreless linear actuators which minimize the force ripples and power dissipation. One or more spatial harmonics of the force ripples are reduced for suitable magnet and coil geometries. Equations for parameter values of these geometries are given, and minima of force ripples and dissipation are determined by evaluating all combinations of...
The operational efficiency of ultra fast actuators used as drives in high voltage direct current breakers are at best 5 %. To boost their efficiency, the design of the energizing circuit is crucial. A multi-physics finite element method (FEM) model coupled with a SPICE circuit model that is able to predict the performance of the actuator with an accuracy of at least 95 % has been developed and verified...
This paper presents the design of magnetic coil for relativistic magnetron (RM) for LIA (Linear Induction Accelerator)-400 systems. Vacuum improves the efficiency of RM for HPM generation. Magnetic field in RM is very critical parameter and should be nearly constant in the active region [1, 2]. Typical coils are helical in nature, which have multi turns of varying radius. Magnetic field calculation...
A fault-tolerant machine used for safety-critical tasks must a) guarantee at least a reduced-performance operation in case of partial machine fault and b) guarantee avoidance of drive mechanical jam/stall in case of total machine fault, to allow for the intervention of the back-up systems. Classical hydrostatic transmissions used on board ships for critical tasks such as rudder and stabilizing fin...
In this paper a new type of hybrid reluctance actuator is presented. This linear hybrid reluctance actuator is a two phase double sided actuator in which the stator is composed by four normalized U cores, each with a coil wrapped around the yoke connecting the two arms of the core or with two coils wound on each of the arms and a permanent magnet placed near the air gap between and in contact with...
The bearingless flux switching slice drive is a recently introduced motor topology in the field of bearingless drives. It combines the magnetic rotor suspension of bearingless slice drives with the torque generation of flux-switching motors. Due to lack of magnets embedded in the rotor, the topology offers advantages in applications with high temperature working conditions. This paper describes the...
This paper proposes a new active tension system which is used in coil winding machine for BLDC motor manufacturing. A comparison of winding condition between normal coil such as round shape coil, rectangle shape coil and BLDC coil is presented. To overcome the harsh winding condition of BLDC coil winding, a new wire accumulator is proposed to store or release a wire when the wire is stretched or sagging...
We present a scaling model for electrically-actuated needle free jet injectors, establishing the relationship between injection volume and motor size. Using an analytical electromagnetic model for the motor, we derive an optimal motor design, and show that this design is approximately scale-invariant. To illustrate the utility of this model, we then describe the design of a motor for use with 300μL...
A redefinition of the International System of Units, the SI, is impending and could occur as early as 2017. After redefinition, a means to realize the unit of mass is required. A watt balance is a promising device to realize the unit of mass at the kilogram level. At the National Institute of Standards and Technology (NIST), construction of a new watt balance with the sole purpose to realize mass...
This paper reports the latest progress made on the BIPM watt balance project. The type A uncertainty of the Planck constant measurements was reduced from 1.4 parts in 106 to about 5 parts in 107. The new magnet was successively fabricated and assembled with an expected high uniformity of the flux density of several parts in 104. Several new components are being introduced into the apparatus which...
The Joule Balance is one of the several promising methods for the precise measurement of the Planck constant h to redefine the kilogram. Compared with the Watt Balance, it benefits from its all static measurements. For the new generation of the Joule balance, a magnet system with high-permeability material is designed to reduce the problem of coil heating. Simulations are carried out to demonstrate...
The design of the new permanent-magnet driven watt balance and novel mechanical features will demonstrate the high-precision capabilities of a new watt balance mass measurement system. This article will introduce the concept of replacing the counter mass with an auxiliary mass and precision alignment of the coil using a large flexure. The system is expected to have overall uncertainties on the order...
This paper presents the modeling and development of a micromanipulation system that can provide continuous force to manipulate a micro-particle through an externally applied magnetic field. This system consists of six electromagnetic coils and the size of the micro-particle to be manipulated is less than 30µm. The magnetic field maps generated from the electromagnets are first simulated using a finite...
Electrode arrays used in neural recording and stimulation applications must be implanted carefully to minimize damage to the underlying tissue. A device has been designed to improve a surgeon's control over implantation parameters including depth, insertion velocity, and insertion force. The device has been designed to operate without contacting tissue and to respond to tissue movements in real time...
This paper presents a tubular linear flux-switching permanent magnet (TLFSPM) motor. It has an inner mover which only consists of iron core, and stator which contains the magnets and armature windings. The objective of this paper is to propose the TLFSPM motor design and mathematical model. This motor has a smaller cogging force and force ripple, in addition, it overcome unbalanced magnetic circuit...
This paper presents electric release brake which is mainly used for safety purpose where emergency stop is required in automation or process industry. Brake is in engage condition when power cut occurs intentionally or accidently. For the given brake, coil is designed to get the required magnetic force. Due to friction between armature plate and body, the air gap between them increases. Magnetostatic...
This paper deals with the design optimization of iron-cored linear motor with trapezoidal permanent magnets (PMs) configurations. Such motor is a short-stroke, single-phase tubular linear permanent magnet motor (TLPMM). The motor equipped with a quasi-Halbach magnetized moving-magnet armature and stator with a single slot and a single coil. The predicted magnetic field distribution in the airgap,...
Typical application of solenoid that is discussed in this paper is to operate pneumatic valves under harsh aerospace environmental conditions and high endurance requirements. A thorough analysis of force balance is required to ensure that solenoid will function under all worst operating conditions. A numerical simulation based on finite element (FE) methods is used for evaluating electromagnetic force...
The paper investigates on the use of a Finite Elements Method analysis to simulate the behavior of a moving coil loudspeaker and its magnet motor. A geometrical model is prepared, suitable for FEM analysis; an electrical model is prepared and linked to the mechanical equations. The system as a whole is simulated by means of the Matlab tool Simulink. The model is completely general, and it can simulate...
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