• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.50 no.6
• /
• pp.273-281
• /
• 2001

In order to overcome the demerit and to improve the operation characteristics of Moving Coil type Linear Oscillatory Actuator(MC-LOA) with single-pole permanent magnet, this paper presents two models having the balanced magnetic circuit by multi-pole permanent magnet. They are short coil type with two-pole single-sided and two-ple double-sided permanent magnet. The characteristics between single-pole and multi-pole permanent magnet type MC-LOA are compared. As a result, multi-pole type MC-LOA has more merits than single-pole type about operation characteristics improvement and machine volume. The characteristics analysis is performed by their dynamic analysis composed of kinetic and electric equations and Finite Element Method(FEM). The propriety of multi-pole type MC-LOA model is verified with analysis results.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.55 no.1
• /
• pp.21-26
• /
• 2006

This paper deals with the dynamic analysis and experiments of moving-magnet linear actuator with/without spring. On the basis of two dimensional (2-D) analytical solutions and experiments, control parameters such as thrust constant, back-emf constant, inductance and resistance are obtained. And then, dynamic simulation algorithm is established from the voltage and motion equation. Finally, for various values of frequency, dynamic simulation results for characteristics of current and displacement of moving-magnet linear actuator with and without spring are presented and confirmed through the experiments. In particular, This paper applies the PWM voltage waveform obtained from a DSP for bidirectional voltage drive to the actuator.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.10
• /
• pp.1223-1228
• /
• 2011

A moving-coil type linear actuator has been widely used in the system reciprocating short stroke because of its several advantages, such as the structural simplicity, low weight and a fast control response speed. This paper presents a design approach for improving the actuating performance with a clear expression of optimal configuration represented by a level set function. The optimization problem is formulated to minimize the variation of magnetic force at every moving displacement of the mover for fast and easy control. To consider the manufacturability of actuator, the concept of phase-field model is incorporated to control the complexity of structural boundaries. To verify the usefulness of the proposed method, the core design example of cylindrical linear actuator is performed.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.48 no.5
• /
• pp.241-248
• /
• 1999

Recently, many linear motion generators and motors are rapidly finding applications that ranges from short stroke linear motion vibrators, such as dynamic cone type loudspeakers to stirling engine driven linear reciprocating alternators, compressors, textile machines etc. The stroke-length may go up to 2m, and the maximum speed is in the range of 5 to 10m/s with oscillating frequency as high as 15 kHz. Therefore, the linear oscillating actuators(LOAs) may be considered as variable speed drivers of precise controller with stoke-length and reversal periods during the reciprocating motion. In this paper, the design, fabrication, experiments, and extraction of control parameters of a moving coil type LOA for driving of linear reciprocating motion control systems, are treated. The actuator consists of the NdFeB permanent magnets with high specific energy as the stator produced magnetic field, a coil-wrapped nonmagnetic hollow rectangular bobbin structure, and an iron core as a pathway for magnetic flux. Actually, the design is accomplished by using FEM analysis for the basic configuration of a magnetic circuit, and characteristic equations for coil design. In order to apply as the drivers of a linear motion reciprocating control system, the control parameters and circuit parameters, such as input voltage-stoke, exciting frequency-stoke, coil inductance and so on, are extracted from the analysis and experiments on concerning a fabricating LOA.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.49 no.3
• /
• pp.180-187
• /
• 2000

A moving-coil-type linear oscillatory actuator(LOA) consists of the NdFeB permanent magnets with high specific energy as the stator, a coil-wrapped nonmagnetic hollow rectangular structure. The LOA system was represented by the voltage equation of coil and the mechanical equation of motion. This set of equations was manipulated in state-space form. The EMF constant kE of equation parameters in state-space form can be obtained by using the induced voltage in armature coils at open circuit test. kE and other parameters provide the system matrices and transfer function for frequency response and dynamic simulation. Voltage source inverter-fed LOA is examined aiming to compare with results of simulation.

• Proceedings of the KIEE Conference
• /
• 2002.07b
• /
• pp.673-675
• /
• 2002

In this paper. the lumped electrical circuit approach of mass/spring system is used to model the mechanical aspects according to the frequency. Therefore, the mass/spring system can be dealt with here and linked with the equivalent circuit of electric linear oscillatory actuator(LOA). Analysis models are double-coil type linear compressor for stirling refrigerator. The compressor consists of the moving coil LOA, piston, and spring. The electro-mechanical system with mass and spring can be represented using the lumped electrical circuit. We present the system impedance and dynamics of moving coil linear compressor.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.64 no.4
• /
• pp.537-544
• /
• 2015

This paper provided two types of design method on moving core type LOA and one type of design method on moving coil type LOA, and compared and examined each of its characteristics. In order to conduct parametric design process, voltage equation was used to schematize Lmin/K and L/M map, and the schematized map was used to determine Lmin, K or L, M. In order to meet requirements such as thrust force and input voltage and to satisfy the target values of Lmin, K or L, M, the types and sizes of each type were designed using geometry design process. 2-FEA was conducted for each of the designed model. After examining thrust force based on the location of the mover, Type-1 showed radical change in thrust force as movers moved, and Type-2 and Type-3 showed constant appearance of thrust force. The total volume of the designed LOA model was compared to select the model with highest thrust force density. Also, the weight of the mover for each model was compared in order to select the model that was predicted to have highest mechanical responsiveness and stroke characteristics.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.53 no.4
• /
• pp.213-223
• /
• 2004

In the machine tool industry, direct drive linear motor technology is of increasing interest as a means to achieve high acceleration, and to increase reliability. The advantages of such a motor are that it has a good linearity and has no need of such mechanical energy conversion parts, which change rotary motion into linear motion, as screws, gears, chains etc In this paper, two structures of LOA are analyzed. One is the moving-coil type LOA and the other is moving-magnet type LOA. Two types of LOA are analyzed, with reference to the following parameters as variables: magnetic field, flux linkage, motor thrust and back emf. These variables are derived by the use of analytical method in terms of two-dimensional rectangular coordinate system. The maximum values of thrust according to such design parameters as air-gap length and magnet height for each model is also represented. The results are validated extensively by comparison with finite element method. In particular, we experiment moving-coil LOA which is already manufactured and confirm that the experimental results are shown in good agreement with analysis through the comparison of between analytical and experimental results

• Proceedings of the KIEE Conference
• /
• 2000.07b
• /
• pp.681-683
• /
• 2000

This paper presents to find suitable driving voltage source for moving-coil-type linear oscillatory actuator(LOA). Thus, we construct control system and proposed three type driving voltage source. This scheme demonstrated experiments. Then, we find suitable driving voltage source for LOA.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.11b
• /
• pp.794-798
• /
• 2002

This paper deals with a moving coil type linear motor for fast access of the miniature ODD. This slim-line motor is composed of the mover supported by guide mechanism, the coil wound into it, and the yoke attached to the permanent magnet for stator. The driving force is generated by the PM of the stator and the current in the coils of the mover. Magnetic circuit analysis and Finite Element Method are applied to estimate the thrust force at air gap. In order to compare the force characteristics between two methods, various experiment results are applied to verify on a prototype. Also the flexible modes of the motor are predicted through the FEM and the structural components are modified to locate this on high frequency region.