• Title, Summary, Keyword: Linear motor

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Linear Motor Damper for Vibration Control of Flexible Structure (유연 구조물의 진동제어를 위한 선형모터댐퍼)

  • Sim Sangdeok;Kang Hoshik;Song Ohseop;Kim Youngchan;Kim Doohoon
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.4
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    • pp.492-498
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    • 2005
  • A linear motor damper based on the linear motor principle is developed to suppress structural vibration. This paper deals with the design, analysis, and manufacture of the linear motor damper. It is designed to be able to move the auxiliary mass of 1500kg, up to $\pm250mm$ stroke. The control algorithm was designed based on LQG control logic with acceleration feedback. Through performance tests, it was confirmed that the developed hybrid mass damper has reliable feasibility as a control device for structural control. In addition, the linear motor damper is more economical than both hydraulic and electric motor driving mass damper with respect to simple structure and low maintenance cost. A series of performance tests of the linear motor damper system were carried out on the full-scale steel frame structure in UNISON Corporation. Through the performance tests, it was confirmed that acceleration levels are reduced down 10dB for first mode of structure

Design of a Moving Magnet Type Linear DC Motor (가동 자석형 선형 직류 전동기의 설계)

  • Jung, H.J.;Kim, Y.;Baek, S.H.;Yoon, S.Y.;Kim, P.S.;Kwon, S.D.
    • Proceedings of the KIEE Conference
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    • pp.224-227
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    • 1998
  • Linear motors are increasingly employed as direct actuators replacing the more conventional systems composed by a rotating motor and a mechanical device. Linear DC motor is useful in a high speed and high accuracy positioning system with a feedback controller. Because of these advantages, linear DC motors have already been used as motors of pen recorders and magnetic disk storage devices, these are moving coil type linear DC motors as these movers are light. Moving magnet type linear DC motor has advantages at long stroke motors because its mover's feeding wires for driving is not necessary. This paper is concerned with the analysis of linear DC motor that is moving magnet type with unipolar. In order to analyze the dynamic behaviour a mathematical model based on a simplified field analysis developed. A two dimensional finite element field solution is employed in order to illustrate the effect of yoke saturation and motor performance. It is deduced the relation between the limit value of the thrust of the linear DC motor and the dimension of the yokes.

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Optimization of the Thermal Behavior of Linear Motors with High Speed and Force [$1^{st}$Paper] (고속$\cdot$대추력 리니어모터의 열특성 최적화 [1])

  • Eun, In-Ung
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.6
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    • pp.184-191
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    • 2002
  • This paper presents the thermal behavior of a synchronous linear motor with high speed and force. Such a linear motor can successfully replace ball lead screw in machine tools because it has a high velocity, acceleration and good positioning accuracy. On the other hand, low efficiency and high heating up during operation are disadvantage of linear motors. For the application of linear motors to machine tools a water-cooling system is often used. In this research, structure of the linear motor and water cooler is changed to improve the thermal behavior of the linear motor. Some important effects of an integrated cooler, an U-cooler and a thermally symmetrical cooler are presented.

Transient Response Characteristic of a Linear Actuator in a Spring Stiffness Variations (공진형 선형 액추에이터의 스프링 강성 변화에 따른 과도응답특성)

  • Kang Do-Hyun;Hong Do-Kwan;Woo Byung-Chul
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.54 no.3
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    • pp.134-138
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    • 2005
  • A typical conventional systems of a linear motion use rack and pinions or ball screws to convert rotary motions from DC servo motors. A linear motor has been used a several field for a MEMS technology and a aircraft carrier. We have studied a transient response of a linear actuator with a damping ratio, spring constant and a pressed power for a constant stroke control.

Synchronizing Characteristics of the Linear Induction Synchronous Motor (영구자석형 리니어 유도 동기모터의 동기화에 관한 실험적 검토)

  • Jeon, Woo-Jin;Lee, Ju;Jeon, Hye-Jeong;Kamiya, Vushi
    • Proceedings of the KIEE Conference
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    • pp.972-974
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    • 2000
  • In this paper, we describe the starting and synchronizing methods in the linear induction synchronous motor. The proposed motor consists of one pair of linear synchronous motors (LSMs) and an additional linear induction motor (LIM). The primary cores have a common ring winding, and solid conductors are arranged in both LIM and LSM. From the investigation by analysis and experiment, we verify that the proposed motor is effective for practical use.

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Design and Operating Characteristics of Cylindrical Linear Motor for Long Stroke Precision Stage (롱 스트로크 정밀 스테이지용 원통형 리니어모터의 설계 및 운전 특성)

  • An, Geuk-Sub;Kim, Houng-Joong;Ahn, Jin-Woo;Koseki, Takafumi
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.1
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    • pp.63-70
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    • 2011
  • This paper presents the design and operating characteristics of the novel cylindrical linear motor which is designed for the long stroke XY stage. In the long stroke structure, the air gap is changed by the distortion and bending effects, and it makes additional position error in the XY stage. In order to consider the distortion and bending effects of the long stroke, the field part of the cylindrical linear motor is designed as an open structure, and the stroke is supported by the bridge guide which is positioned in the open field part. The mechanical bridge guide can reduce the bending effects of the stroke and can keep a constant air gap. The detailed design process of the proposed cylindrical linear motor is presented in this paper. The proposed motor is analyzed by the 3D FEM technology. The practical XY stage which uses the proposed motor is tested to verify the propose novel cylindrical linear motor. The FEM and experimental results show the effectiveness of the proposed motor.

A study on thermal characteristics of linear motor for high speed machining tools (공작기계 고속이송용 리니어 모터의 열 특성에 관한 연구)

  • 정일용;강은구;이석우;최헌종
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.98-101
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    • 2001
  • Linear motor feature a direct connection to the machine tool, therefore a direct route for heat transfer. The heat dissipation of linear motor machine is affected by the maximum temperature rise of the primary part, coil and the cooling method. To minimize temperature induced dimension changes and decrements of performance, linear motor machine require effective cooling mechanism. To evaluate cooling performance of existing linear motor machine, some experiments about temperature profile are performed using thermocouple recorder. Due to the lack of information about internal structure, only some finite element modeling is prepared and analyzed.

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Effects of Insulation Layer upon the Thermal Behavior of Linear Motors

  • Eun, In-Ung
    • Journal of Mechanical Science and Technology
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    • v.17 no.6
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    • pp.896-905
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    • 2003
  • A linear motor has many advantages next to conventional feed mechanisms: high transitional speed and acceleration, high control performance, and good positioning accuracy at high speed. Through the omission of a power transfer element, the linear motor shows no wear and no backlash, has a long lifetime, and is easy to assemble. A disadvantage of the linear motor is low efficiency and resultant high-temperature rise in itself and neighboring structures during operation. This paper presents the thermal behavior of the linear motor as a feed mechanism in machine tools. To improve the thermal behavior, an insulation layer is used. By placing the insulation layer between the primary part and the machine table, both the temperature difference and the temperature fluctuation in the machine table due to a varying motor load are reduced.

Development of Iron Core type Linear Motor for Machine Tool (공작기계용 철심형 니니어모터 기술개발)

  • 정재한;박재완
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.33-36
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    • 1997
  • The merits of linear motor are high speed, high acceleration and goad positioning accuracy. In addition, Linear motor for high quality machme tool call for high thrust, high stiffness. In using linear motor we also consider thrust ripple, detent force and thermal behavior. In this research, Iron core type single sided linear DC motor(LDM) is designed which thrust is 6,000 N. To accomplish this design, Various research is hlfilled l~ke the relation of thrust and permanent magnet position angle, the variation of detent force and thrust ripple, dynamic characteristics, and so on.

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A study on thermal and driving characteristics of linear motor for high speed machining tools (공작기계 고속이송용 리니어 모터의 열특성 및 운동특성에 관한 연구)

  • 최헌종;정일용;강은구;이석우
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.414-419
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    • 1997
  • Linear motor feature a direct connection to the machine tool, therefore a direct route for heat transfer. The heat dissipation of linear motor machine is affected by the maximum temperature rise of the primary part, coil and the cooling method. To minimize temperature induced dimension changes and decrements of performance, linear motor machine require effective cooling mechanism. 1'0 evaluate cooling performance of existing linear motor machine, some experiments about temperature profile are performed and evaluated using thermocouple recorder. Due to the lack of information about internal structure. only some finite element modelling is prepared and analyzed.

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