• 한국생산제조학회지
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• 제8권5호
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• pp.96-101
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• 1999

This study suggests an algorithm for tooth profile generation of free from curve involute gear, a special gear of which the pitch line is a free curve instead of a circular one. For the first, a methodology for calculation of the tooth curve is developed and formulated Then the formulated algorithm, is programmed for manufacturing and verified by computer graphics. Next the calculated results as changed in to NC codes to apply to wire electric discharge machine(WEDM). Finally, the machined gear is examined in engagement with a standard involute gear.

• 한국공작기계학회논문집
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• 제11권3호
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• pp.80-85
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• 2002

The free curve gear is a non-circular gear without any relating center, which can perform free curve motion for complicated mechanisms, and minimize the work area. In this study, an algorithms for tooth profile generation of free curve involute gear is developed. The algorithm uses the involute gear creating principle in which a gear can be generated by rolling with another standard involute one. Cycloid me and third polynomial curve gears were designed and verified by computer graphics. These gears are manufactured in the wire-cut EDM and examined in engagement with a standard spur gear. The results showed that the proposed algorithm is successful to design and to manufacture the free curve gear with concave and convex profiles.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.530-532
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• 2002

This paper presents an optimum design of herringbone grooved journal bearing for spindle motor of hard disk drive (HDD) system. In addition to the conventional “rectangular” groove, various groove profiles are designed. The stiffness and damping coefficients of the oil film and frictional torque are calculated and compared for tile various groove profiles. The “circular”, “valley”, and “reversed saw tooth” grooves do not produce high direct stiffness, since they partly increase the groove depths in the direction of lubricant flow, causing to reduce the pumping action of the bearing. The maximum direct stiffness can be obtained by the “rectangular”, “saw tooth”, and “step” grooves. With the same cross sectional area of the grooves, these three grooves have the same maximum stiffness, damping coefficients, and frictional torque. Among these recommendable grooves, the saw tooth groove may keep its original profile for long, enduring metal-to-metal contact during startup and shutdown.

• 유공압시스템학회:학술대회논문집
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• 유공압시스템학회 2010년도 춘계학술대회
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• pp.25-32
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• 2010

A geortor type pump is widely used in lubrication and actuator systems. Especially the pump is an essential machine element of an automotive engine to feed lubrication oil and power source of automatic transmission. A gerotor is a planar mechanism consist of a pair of rotor and circular tooth of stator assembly which forms a closed space. However, related industries do not have necessary technology to design and optimize the pump and paid royalties of gerotor profile on an advanced company. Also, gerotor profiles with setting design parameter have not been sufficiently analyzed from a theoretical view. Therefore, it is very difficult for designer to decide the specifications of the gerotor profiles, and calculation and fluctuation of flow rate is not yet confirmed. In this study, theoretical analyses and optimal design of the gerotor profiles have been performed numerical method by mathematical base. An automated design system of the tooth profile has been developed through MATLAB GUI Program considering various design parameters.

• 한국CDE학회논문집
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• 제17권3호
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• pp.156-163
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• 2012

Real-time three-dimensional shape measurement is becoming increasingly important in various fields, including medical sciences, high-technology industry, and microscale measurements. However, there are not so many 3D profile tools specially designed for specifically narrow space, for example, to scan the tooth shape of a human jaw. In this paper, a real-time 3D intraoral scanner is proposed for the measurement of tooth profile in the mouth cavity. The proposed system comprises a laser diode beam, a micro charge-coupled device, a graticule, a piezoelectric transducer, a set of optical lenses, and a polhemus device sensor. The phase-shifting technique is used along with an accurate calibration method for the measurement of the tooth profile. Experimental and theoretical inspection of the phase-to-coordinate relation is presented. In addition, a nonlinear system model is developed for collimating illumination that gives the more accurate mathematical representation of the system, thus improves the shape measurement accuracy. Experiment results are presented to verify the feasibility and performance of the developed system. The experimental results indicate that overall measurement error accuracy can be controlled within 0.4 mm with a variability of ${\pm}0.01$.

• 드라이브 ㆍ 컨트롤
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• 제17권1호
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• pp.1-12
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• 2020

This study was to develop a simulation model of a compound planetary gear reducer for the final driving shaft using a gear analysis software (KISSsoft, Version 2017, KISSsoft AG, Switzerland). The aim of this study is to analyze transmission error and the tooth load distribution through micro-geometry using the simulation model. The tip and root relief were modified with Micro-geometry in the profile direction, and crowning was modified with Micro-geometry in the lead direction. The transmission error was analyzed using the PPTE (Peak to Peak Transmission Error) value, and the tooth load distribution was analyzed for the concentrated stress on the tooth surface. As a result of modifying tip and relief in the profile direction, the transmission error was reduced up to 40.7%. In the case of modifying crowning in the lead direction, the tooth load was more evenly distributed than before and decreased the stress on the tooth surface. After modifying the profile direction for the 1st and 2nd planetary gear train, the bending and contact safety factors were increased by 31.7% and 17%, and 18.3% and 12.5% respectively. Moreover, the bending and safety factors after modifying lead direction were increased by 59.5% and 32.7%, respectively for the 1st planetary gear train, and 59.6% and 43.6%, respectively for the 2nd planetary gear train. In future studies, the optimal design of a compound planetary gear reducer for the final driving shaft is needed considering both the transmission error and tooth load distribution.

• 대한치과교정학회지
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• 제24권1호
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• pp.135-147
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• 1994

Facial esthetics is one of the most important goal of the orthodontic treatment and main concern of many patients. Facial esthetics should be considered in orthodontic diagnosis and treatment planning. Prediction of soft tissue profile changes after orthodontic tooth movement should be considered as well. The purpose of this study was to find out the effect of orthodontic treatment on lip profile in adult patient. The pre and post treatment cephalometric roentgenograms of 87 female adult with bimaxillary protrusion were used to analyze lip profile change. All subjects were treated with four bicuspids extraction. Obtained results were as follows . 1. Lip thickness changes after incisor retraction showed different patterns according to areas of the lip. The thickness of the red lip area showed 2.78 mm increase in average. In contrast the thickness of the cutaneous area showed 0.65 - 0.7 mm decrease according to the different cutaneous areas. 2. The length of the red lip area decreased(1.3mm) after incisor retraction. 3. The length of the cutaneous lip area increased(2.9mm) after incisor retraction.

• 한국지능시스템학회논문지
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• 제16권3호
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• pp.315-320
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• 2006

산업 현장에서는 많은 종류의 감속기들이 사용되고 있다. 그 중 로봇에서는 사이클로이드(cycloid) 치형 혹은 인벌루트(involute) 치형을 가진 고정밀도의 감속기를 사용한다. 그 이유는 로봇 시스템에서는 위치 제어를 하는데 있어서 고정밀의 감속기를 사용하는 것이 필수적이기 때문이다. 본 논문에서는 기본적으로는 삼각형 치형을 가지고 있지만 새로운 직선치형을 갖는 로봇 감속기(RSR)를 제안한다. 제안한 감속기는 유한요소 해석법을 이용한 강도, 응력, 강성 테스트에서 좋은 결과를 얻을 수 있었으며, 편심계수를 변화시켜 최적의 치형 운동을 얻을 수 있도록 설계하여 응력이 적게 걸리고 소음을 낮출 수 있도록 하였다.

• 구강회복응용과학지
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• 제25권1호
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• pp.23-29
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• 2009

1933년 Dewey와 Zugsmith가 처음 ovate pontic을 소개한 이후 1990년대 말부터 임상적으로 널리 사용되고 있다. Ovate pontic은 심미적이고 위생적인 자연치의 emergence profile을 더 정교하게 재현할 수 있는 방법으로 알려져 있다. 특히, 상악 전치부가 상실된 경우 발치 시기부터 ovate pontic의 형태를 가진 레진 임시수복물을 제작해 줌으로서 치간유두를 보존시켜 치간공극의 발생을 최소화하여 심미적이고 발음의 이상이 없는 최종보철물을 제작할 수 있다. 본 증례에서는 치아상실부위에서 치간유두의 상실을 최소화하고 자연치와 유사한 emergence profile을 지닌 보철물을 제작하기위해 ovate pontic을 이용하여 처치한 치험예를 문헌고찰과 함께 보고하고자 한다.

• 한국지능시스템학회논문지
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• 제17권7호
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• pp.952-956
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• 2007

산업현장에서는 공장 자동화의 발전에 따라 많은 로봇들이 사람을 대신하고 있다. 일반적으로 산업 현장에서 사용되는 로봇은 고정밀도의 감속기를 필요로 한다. 고정밀의 제어를 위해서는 cycloid 치형 혹은 인벌류트 치형을 가진 감속기를 사용하게 된다. 이러한 감속기는 낮은 백래쉬와 높은 감속비를 가지면서 동시에 치형의 높은 강성을 필요로 한다. 본 논문에서는 새로이 고안한 직선 치형을 가진 로봇 감속기(RSR) 치형의강성을 FEM 해석을 통해 실제로 적용이 가능한지 여부를 시뮬레이션 해보았으며, 실제로도 적용이 가능함을 알 수 있었다.