• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.1088-1094
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• 1997

An indirect cutting torque and cutting force estimation method is presented. This method uses a time-domain model between the spindle motor power, which calculated form measured spindle motor current and voltage. Spindle motor power is linear with cutting torque in this model. The cutting force is proportional to the cutting torque. Using trial cut, parameters are determined. Static sensitivity is suitable for various cutting conditions. The presented method is verified under several cutting tests on the CNC horizontal machining center.

• 한국정밀공학회지
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• 제16권6호
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• pp.133-140
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• 1999

In this study, a monitoring method to detect chip disposal state in drilling system based on neural network was proposed and its performance was evaluated. If chip flow is bad during drilling, not only the static component but also the fluctuation of dynamic component of drilling. Drilling torque is indirectly measured by sensing spindle motor power through a AC spindle motor drive system. Spindle motor power being measured drilling, four quantities such as variance/mean, mean absolute deviation, gradient, event count were calculated as feature vectors and then presented to the neural network to make a decision on chip disposal state. The selected features are sensitive to the change of chip disposal state but comparatively insensitive to the change of drilling condition. The 3 layerd neural network with error back propagation algorithm has been used. Experimental results show that the proposed monitoring system can successfully recognize the chip disposal state over a wide range of drilling condition even though it is trained under a certain drilling condition.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.28-30
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• 1996

In the paper the authors deal with inverter fed induction motors design criteria for having a wide constant power range. In particular, the flux weakening operation is the main feature considered. The design target concerns the possibility of having a wide flux weakening region avoiding or limiting, at the same time, to oversize the motor and the inverter.

• 전기학회논문지P
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• 제59권2호
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• pp.151-153
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• 2010

This paper is presented for the development of the brushless DC(BLDC) motor for the spindle motor of hard disk drives(HDD). A new BLDC Motor has the use of insulated, compacted, and iron powder for the armature core material of BLDC motors. Insulated iron powder in this paper is generally called soft magnet composite(SMC). The SMC is used for the stator of the motor instead of the laminated steel core. The motor used by SMC can have the good advantages in condition of the high frequency input power and small sized motor. It gets much more high efficiency than laminated steel core at same input power. The proposed motor has a technique of speed sensorless control. Experimental results show the performance of the proposed BLDC motors for an HDD.

• 한국정밀공학회지
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• 제30권11호
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• pp.1187-1192
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• 2013

In the case of 4 wheel drive (4-WD) type car, power switching occurs to 4-WD by operating lever or switch that operates power switching device attached in transfer case which can operate motor by electric signal. So if the RPM of motor is high, power switching will not exactly occur and can cause damage to gear in transfer case according to circumstances. So in this study, we applied 2 level of planet gear type motor spindle of motor drive part of a power train. And conducted decelerating to increase torque to switch power safe and accurately. Also, we researched efficiency of gear by designing reduction gear ratio and gear type and by calculating contact stress and bending strength. Based on researched content, we made drive head of power switching device and a reduction module which uses type that uses motor spindle as sun gear and ring gear as cover.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.473-477
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• 2005

This paper presents a highly efficient HDD (Hard Disk Drive) spindle motor with a passive magnetic thrust bearing and a fluid dynamic journal bearing and its effectiveness is verified through experiment. It eliminates the mechanical friction loss of a thrust bearing which is around 18% of total power consumption of a 3.5' HDD spindle motor, by replacing a conventional fluid dynamic thrust bearing with a passive magnetic thrust bearing. The passive magnetic thrust bearing using permanent magnets is inherently unstable in radial direction. However, the radial fluid dynamic force of the fluid dynamic journal bearing counterbalances the radial magnetic force of magnetic thrust bearing to achieve the stability as the motor spins up. It has less or equivalent runout and less flying height than the conventional spindle motor.

• 전력전자학회논문지
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• 제10권2호
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• pp.186-193
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• 2005

본 논문에서는 산업체 CNC(Computer Numerical Control) 분야에서 사용되는 빌트인 타입 스핀들 모터를 구동하기 위한 기법을 제시하였다. 저속 영역에서 유리한 전류 모델과 고속 영역에서 유리한 전압 모델을 혼합해서 사용하는 고피나스 모델 자속추정기는 회전자 자속추정을 위하여 이용하였다. 그리고 약계자 제어를 사용하여 스핀들 모터를 고속 운전하였다. 시뮬레이션과 실험을 통해 약계자 영역에서의 스핀들 모터 고속운전을 확인하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.605-609
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• 2000

This paper presents a development of the Pulse Width Modulation ASIC for control of the AC servo or spindle motor in machine tools. The ASIC is designed two PWM functions for simultaneous control of a converter and an inverter. Also the device includes additionally two UART functions for interfacing the RS232C with PC or other devices. The device is connected to the microprocessor of Intel or Motorola by bus interface. The required output voltage and frequency for the motor control is programmed to the PWM block and the corresponding switching signals are calculated and generated with regard to the programmed value.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.8-13
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• 2001

In the turning process, the feed is usually selected by a machining operator considering workpiece, cutting tool and depth of cut. Even if this selection can avoid power saturation or tool breakage, it is usually conservative compared to the capacity of the machine tools and can reduce the productivity significantly. This paper proposes a selection method of the feed and the reference cutting force based on MRR(material removal rate), maximum spindle power and specific energy. In order to estimate and control cutting force accurately in transient and steady state, this study utilizes a synthesized cutting force estimation method and a Fuzzy controller. The experimental results present that these systems can be useful for the FMS(flexible manufacturing system) and unmanned automation system.

• 대한기계학회논문집A
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• 제26권7호
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• pp.1446-1452
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• 2002

In the turning process, the feed is usually selected by a machining operator considering workpiece, cutting tool and depth of cut. Even if this selection can avoid power saturation or tool breakage, it is usually conservative compared to the capacity of the machine tools and can reduce the productivity significantly. This paper proposes a selection method of the feed and the reference cutting force based on MRR(material removal rate), maximum spindle power and specific energy. In order to estimate and control cutting force accurately in transient and steady state, this study utilizes a synthesized cutting force estimation method and a Fuzzy controller. The experimental results show that these systems can be useful for the unmanned turning process.