• Journal of the Korean Society for Precision Engineering
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• v.19 no.12
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• pp.109-119
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• 2002

In this paper, mechanism design of optical pickup actuator for fast access is proposed. This actuator is composed of moving magnet type actuator and moving coil type actuator for tracking and fine motion, respectively. Moving magnet type tracking actuator is configurated by two permanent magnets and four air-core solenoids. Additional damper by induced current in tracking actuator can reduce the transient vibration between the coarse seeking servo and fine seeking servo. Variable stiffness can be acquired by applying current to air-core solenoid simply. This actuator can achieve fast access by these additional damper and stiffness. Performance of this actuator is predicted through the FEM, simulation and simple experiment. Settling time for transient vibration is reduced to 14.7% according to simulation result.

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

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.742-744
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• 2001

Moving flat core LOA consists of iron flat core as a mover and electric magnet as a stator and operated by electromagnetic force between mover and stator. In a moving flat core type, it takes advantage of doing not have to be equipped with power supply device, having a lower manufacturing cost. But it has a lower linearity and precision. In this paper, a static characteristics of LOA were studied and analyzed using FEA. Experiments, electromagnetic force and inductance according to air gap and input currents, were carried by exciting coil. And we compared these results one another.

• Journal of Magnetics
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• v.14 no.1
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• pp.47-51
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• 2009

The coreless linear synchronous motor (coreless LSM) has been widely used as a driving source of semiconductor production processes for machine speeding up, positioning accuracy and simple maintenance. However, this coreless LSM suffers the disadvantage of decreased thrust force created by the leakage of magnetic flux. With the goal of increasing the generated thrust force and decreasing the cogging force, the slot of the core part was removed and a moving-coil-type slotless LSM (moving-coil-type slotless LSM) is proposed in this paper. Although this moving-coil-type slotless LSM with a back-yoke at the primary side demonstrated an increase in the generated thrust force, it remained capable of generating the cogging force when the primary side was moved due to the position between the permanent magnet and the back-yoke. Therefore, we attempted to decrease the cogging force of the moving-coil-type slotless LSM. We found that the back-yoke length at the primary side needs to be made $0.5{\tau}$ longer than the integral multiple of the magnetic pole pitch in order to decrease the cogging force created by the moving-coil-type slotless LSM.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.3
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• pp.218-222
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• 2004

We developed the stamper structured mold with moving core type with nano pattern. Among the factors affecting the quality of injection molding plastic parts, We studied the effects of moving core surface heating method on the transcription of injection molding plastic parts with nano structures. Moving core surface heating has been tested by three different methods. The first was conventional injection molding process without heating moving core surface, the second was halogen lamp radiation heating process and the last was MmSH process using gas flame. As a result of making injection molded parts by using thermoplastic amorphous resins such as COC, PMMA, MmSH method which is the most high temperature of moving core surface showed the best nano pattern transcription of the three methods, but the outcome of conventional injection molding process was not better than others.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.663-665
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• 2002

Moving flat core type LOA consists of iron flat core as a mover and electric magnet as a stator and operated by electromagnetic force between mover and stator. First, this paper describes the voltage equation of coil and the mechanical equation of motion. Secondly, the dynamic simulation algorithm is proposed, and system control constant-inductance, resistance-were carried by exciting coil. Finally, we turned out the driving system and the dynamic characteristics of current, voltage and displacement is confirmed by experiment.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.33-35
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• 2003

This paper proposes inserted core type of slotless Permanent Magnet Linear Synchronous Motor(PMLSM) to improve its low thrust density. However, by inserting the core between windings of each phase, detent force is generated. Furthermore, linear motors have the feature of structurally limited length. So, it causes the end-effect in actual operation. So, this paper applies the neural network to this model to minimize detent force and maximize thrust. Also, sub-poles used the to the end parts of the mover for compensating the end-effect.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.50-52
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• 1996

The exiting apparatus for rectilinear reciprocating motion has low efficiency because of various mechanical converting equipments from rotary motion. The LOA(Linear Oscillation Actuator) is the rectilinear reciprocating actuator. This paper shows the operating principle of bifiler winding LOA and the comparison the characteristics of thrust force of no tapered moving core type LOA with the tapered one. Through FEM analysis tapered LOA has the lower peak force and longer stroke than no tapered LOA.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.15-18
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• 1996

In the case of need for reciprocating motion, the study for application of Linear Oscillating Actuator(LOA) is being accomplished. LOA is the simpler and more efficient than other linear apparatus using the rotary motor because LOA produce the thrust force without any converter such as cam, clutch, rack, pinion and belt, etc. We designed the flat moving core type LOA and manufactured for trial. This paper shows the structure and dynamic characteristics of LOA.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.900-902
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• 2000

A moving-coil-type linear oscillatory actuator is consisted of the NdFeB permanent magnets with high specific energy as the stator, a coil-wrapped nonmagnetic hollow rectangular structure and an iron core as a pathway for magnetic flux. The inductance of moving coil and the push/pull effect is obtained from the permeance model of LOA with the open magnetic circuit. The analytical method are verified using the 2D finite element method.