• 한국공작기계학회논문집
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• 제12권2호
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• pp.59-64
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• 2003

Continuously Variable Transmission (CVT) consists of a driving pulley and a driven pulley joined by rubber V-belt. Each pulley consists of a fixed flange and a movable flange. The main advantages of the U with V-belt, which has been Popular in Asia, are a simple mechanism less maintenance and low cost. One of the important factors which have an influence on the performance of the CVT is change of axial distance. Base on an experiment the effects of transfer torque and speed ratio of both driving pulley and driven pulley during the alteration of axial distance were studied.

• Journal of Power Electronics
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• 제14권5호
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• pp.852-858
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• 2014

A novel 12/10 axial field switched reluctance motor (AF-SRM) is proposed for cooling fan applications in this paper. Unlike from conventional structures, the proposed motor uses the axial field instead of the radio field, the rotor is constructed from a series of discrete segments, and the stator poles are constructed from two types of stator poles: exciting and auxiliary poles. This concept improves the torque capability of a previous design by reducing the copper volume, which leads to a higher efficiency. To verify the proposed structure, the finite element method (FEM) and Matlab-Simulink are employed to get characteristics of the proposed SRM. Finally, a prototype of the proposed motor was tested for characteristic comparisons.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1162-1164
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• 2000

Stratum Axial Type BLDC Motor has remarkable efficiency owing to outstanding characteristics of speed and torque as well as its small size. In this paper 2-Degree of Freedom PI (TDOF PI) control method is presented in order to improve the efficiency of Stratum Axial Type BLDC Motor and the simulation proves that the separate control for speed characteristic from answering characteristic of load torque particularly allows the construction of superior control system to PI control system. These results are significant in that the improved Stratum Axial Type BLDC Motor enables the production of much smaller, lighter, and noiseless electric home appliances such as air-conditioner and refrigerator.

• The Journal of Advanced Prosthodontics
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• 제10권5호
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• pp.388-394
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• 2018

PURPOSE. To measure axial displacement of different implant-abutment connection types and materials during screw tightening at the recommended torque by using a contact scanner for two-dimensional (2D) and three-dimensional (3D) analyses. MATERIALS AND METHODS. Twenty models of missing mandibular left second premolars were 3D-printed and implant fixtures were placed at the same position by using a surgical guide. External and internal fixtures were used. Three implant-abutment internal connection (INT) types and one implant-abutment external connection (EXT) type were prepared. Two of the INT types used titanium abutment and zirconia abutment; the other INT type was a customized abutment, fabricated by using a computer-controlled milling machine. The EXT type used titanium abutment. Screws were tightened at $10N{\cdot}cm$, simulating hand tightening, and then at the manufacturers' recommended torque ($30N{\cdot}cm$) 10 min later. Abutments and adjacent teeth were subsequently scanned with a contact scanner for 2D and 3D analyses using a 3D inspection software. RESULTS. Significant differences were observed in axial displacement according to the type of implant-abutment connection (P<.001). Vertical displacement of abutments was greater than overall displacement, and significant differences in vertical and overall displacement were observed among the four connection types (P<.05). CONCLUSION. Displacement according to connection type and material should be considered in choosing an implant abutment. When adjusting a prosthesis, tightening the screw at the manufacturers' recommended torque is advisable, rather than the level of hand tightening.

• Journal of Magnetics
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• 제21권1호
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• pp.94-101
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• 2016

This paper shows a new magnetic field analysis of an interior permanent magnet (IPM) machines with an axial overhang structure wherein the rotor axial length exceeds that of the stator. The rotor overhang used to increase torque density of the radial flux machine is difficult to analyze because of extra consideration of axial direction, and thus it is general for machine designer to take 3-D finite element analysis (FEA) capable of considering both radial and axial complicated geometry in the machine. However, it requires too much computing time for preliminary design especially for optimization process. Therefore, in this paper a 2-D analytic method using a lumped magnetic circuit model (LMCM) is proposed to overcome the problem. For the analysis of overhang effect, the magnetic circuit is separated and solved from overhang and non-overhang regions respectively. For the validation of proposed concept, 3-D finite element analysis (FEA) is performed. From the analysis results, it is shown that our new proposed method presents good performance in terms of calculating electromotive force (EMF) and torque within a short time. Therefore, the proposed model can be useful in design of IPM with an overhang structure.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 제33회 추계학술대회논문집
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• pp.153-156
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• 2009

KSLV-I 2단에 적용된 킥모터는 피치, 요축 자세제어를 위해 고무와 보강제가 번갈아가며 적층된 플렉시블 씰을 사용하였다. 제작된 플렉시블 씰은 노즐에 조립되기 전에 플렉시블 씰의 성능을 확인하기 수압 구동 시험을 수행 하였다. 수압 시험을 통해 플렉시블 씰의 제작 상태를 확인하였으며, 압력 변화에 따른 피치, 요축의 구동 토크 및 축 방향 밀림량을 확인하였다. 수압 시험결과 제작된 플렉시블 씰의 구동 토크는 60kgf-m/deg이하이며, 축 방향 밀림량은 최대 6mm이하를 보이고 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1019-1020
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• 2011

This paper deals with torque analysis of axial flux permanent magnet (AFPM) type eddy current brake (ECB) based on analytical field computation. On the basis of a magnetic vector potential and a two-dimensional (2-D) polar coordinate system, analytical solutions for normal and tangential flux density due to permanent magnet (PM) considering eddy current effect are obtained. And then, using derived analytical field solutions, braking torque and normal force characteristics according to rotor speed are also predicted. A three-dimensional (3-D) finite element (FE) analysis is employed to confirm the validity of analyses.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.669-670
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• 2015

In this paper, rotor design modification of a novel proposed machine termed the Axial Flux Doubly Fed Reluctance Machine (AF-BDFRM) is studied. The main potential advantage of AF-BDFRM is that it has larger torque and power density compared to radial flux-BDFRM. However, with the general rotor pole shape, this machine output back EMF has high THD % and high cogging torque. This paper studies the rotor design modification in the proposed AF-BDFRM to reduce the THD % in inducedd back EMF and cogging torque. Also the transient 3D finite element analysis (FEA) optimization of initial design is presented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.115-117
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• 2002

This paper deals with a cogging torque analysis of the Brushless Motor considering axial displacement of rotor. In this paper, 3D EMCN in combination with 2D FEM is proposed to analyze the cogging torque having 3D Phenomenon. And proposed method is accomplished through dividing analysis region between 2D-region and 3D-region. Moreover, difference of both ends of rotor -diameter is considered by proposed method.

• 대한기계학회논문집B
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• 제31권3호
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• pp.242-247
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• 2007

Energy savings and environmental protection policies have been the general trend in the engine design. The friction power loss associated with the cam mechanism has become important. But it is difficult to measure the torque of rotating valvetrain in real engine environment because most of conventional torque meters are axial type. The objective of this paper is to develop new equipment which can be installed in a rotating camshaft. It uses strain gages to measure the elastic deformation of torque sensor which replaces the cam sprocket. It includes telemetry to transmit torque data via Bluetooth and induction power system to provide adequate power to rotating torque meter. The developed torque meter has good linearity and thermostability. It was installed in a real engine, and successfully measured the valvetrain torque.