• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.5
• /
• pp.1552-1557
• /
• 2010

The cylindrical gear in power window motor assembly is important to doors of automobile. This study is performed for the purpose of getting a manufacturing technique instead of large quantities import and six-cavity mold production. This multi-cavity cylindrical gear is produced under five procedures. The first, mold design of mass-production, the second, making a CAE model for mass-production, the third, manufacturing of sample mold, the fourth, trying-out and measuring of 3 dimensional design, the fifth, acquisition of data analysis and mold modification. Among them, analysis of mass-production using CAE, designing and manufacturing of multi-cavity are successfully performed. In the results, it is concluded that the mold for one gate and eight-cavity based on hot-runner is suitable for making a cylindrical gear.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.29 no.5 s.236
• /
• pp.647-654
• /
• 2005

This research Proposes a Process design of injection molded microcellular plastic gears for enhancing the fatigue strength/durability and accuracy of the gears applying thermodynamic instability to microcellular foaming process. To develop the injection molded plastic gears by way of microceliular process, it is absolutely necessary the following two process design. The first is microcellular forming process for enhancing the strength/durability of plastic gears. To be microcellular process succeeded, based on the microcellular principle, mechanical apparatus is designed where nucleation and cell growth are to be generated renewably. The second is the counter pressure process which is mainly fur improving the tooth surface roughness and the accuracy of microcellular gears. For the former process, screw, nozzle and gas equipment are newly designed, and for the latter, counter pressure by nitrogen gas is intentionally brought about into mold cavity when injecting plastic gears. Based on the proposed process design, using gear mold, experiments of injection molding show that, in internal space of plastic gears, microcellular nuclear cells less than 5 lim in diameter have been generated homogeneously via electron microscope photos.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.7
• /
• pp.726-733
• /
• 2017

A magnetic shutter gear is a device that transfers mechanical power by synchronizing the magnetic field between permanent magnet layers facing circumferentially through a harmonic modulator. However, magnetic gears uses many rare-earth permanent magnets to guarantee comparable torque density to that of mechanical reducer. Hence, we propose a novel axial magnetic gear with a dramatically reduced number of permanent magnets and a closed magnetic path. The torque of the system was compared to that of an existing shutter gear through a harmonic analysis of the air-gap magnetic field. The modulator thickness and open ratio were considered as the primary design parameters, and the cogging effect was analyzed for variation of the reduction ratio. A dynamic model between the high-speed side and low-speed side was derived, and position control was performed for a constructed hardware implementation.

• Proceedings of the KAIS Fall Conference
• /
• 2009.12a
• /
• pp.877-880
• /
• 2009

수문의 개폐는 모터에 의한 회전이 권양기에서 감속 되고 증폭된 회전력이 랙에 의하여 직선 운동으로 바뀌어 회전 방향에 따라 상하로 움직여 열리고 닫히게 된다. 권양기는 상부 모터, 감속기, 메인 감속 장치, 동력 차단장치, 좌측 동력변환장치, 우측 동력 변환장치로 구성된다. 본 논문에서는 핀잭식 권양기의 최적 설계를 위하여 보조기어와 메인기어 트레인의 구조 해석, 진동해석 및 설계와 하중에 버틸 수 있는 상부구조물 몸체의 최적 설계를 통하여 설계변수를 확립한다.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.16 no.5
• /
• pp.205-210
• /
• 2007

The integration method of binary and real encoding in genetic algorithm is proposed to deal with design variables of various types in gear drive design. The method is applied to optimum design of multi-stage gear drive. Integer and Discrete type design variables represent the number of teeth and module, and continuous type design variables represent face width, helix angle and addendum modification factor etc. The proposed genetic algorithm is applied for the gear ratio optimization and the volume optimization(minimization) of multi-stage geared motor which is used in field. In result, the proposed design optimization method shows an effectiveness in optimum design process and the new design has a better results compared with the existing design.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.39 no.7
• /
• pp.665-671
• /
• 2015

The performance of fault diagnostics for a planetary gearbox depends on vibration modulation characteristics, which can vary with manufacturing & assembly tolerance, and load condition. In this paper, a fault diagnostics technique that considers vibration modulation characteristics is proposed for the effective fault detection of planetary gearboxes in wind turbines. For identifying the vibration modulation characteristics in practice, re-sampled vibration signals are processed with narrow band-pass filters. Thereafter, the optimal position of the vibration extraction window is identified for effective detection of faulty signals under the varying vibration modulation characteristics. The proposed diagnostics technique makes it possible to perform robust diagnostics of the planetary gearbox with regard to the changeable vibration modulation effect. For demonstrating the proposed fault diagnostics technique, a 2-kW WT testbed is designed with two DC motors and gearboxes. A faulty gear with partial tooth breakage is machined and assembled into the gearbox.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.9
• /
• pp.1027-1032
• /
• 2012

Two types of very small multiplying gears and arrays have been developed for new dental hand-pieces, and the increased speed ratios, modules, number of teeth, gear diameters, and gear types were calculated based on the dynamics of the machinery. The contacting and bending strengths were evaluated for gear teeth with two design concepts using AGMA equations and finite element analyses, and the contacting stresses on teeth with and without DLC (diamond-like-carbon) coating layers were calculated. Fatigue and tension tests were performed to obtain an S-N curve, the Young's modulus, and the strength of the gear material, and these were utilized in the analyses. Slightly larger stresses were found for 2-axis-type gears than for other types of gears, and the S-N curves showed that a gear lifetime of 109 cycles was satisfied. The contacting stresses in gears coated with DLC were reduced by 30%. A new prototype model of a hand-piece with small gears was successfully fabricated and tested.

• Journal of Power System Engineering
• /
• v.13 no.4
• /
• pp.18-23
• /
• 2009

구면무단변속기(SS-CVT)는 구조가 간단하여 변속기구의 부피와 무게를 기존의 변속기구에 비하여 줄일 수 있으며, 별도의 클러치 없이 출력축의 정회전, 역회전 그리고 중립상태 등을 구현할 수 있다. 본 연구에서는 이러한 구면무단변속기의 기구적 특징과 변속메카니즘을 이용하여 직류모터와 가솔린엔진을 장착한 병렬형 하이브리드차량의 동력전달계를 제안하고자 한다. 이를 위하여 먼저 구면무단변속기의 작동원리에 대해 설명하고 전용 실험장치를 제작하여 무단변속성능을 검증하였다. 또한 직류모터를 보조 동력원으로 사용하는 병렬형 하이브리드차량 동력전달계의 설계를 위해 연결기어비와 구면무단변속기의 변속비를 차량주행성능에 맞추어 설정하였으며, 이를 차량가속성능의 수치 시뮬레이션을 통하여 분석하였다. 시뮬레이션 결과를 바탕으로 구면무단변속기의 하이브리드차량 동력전달계의 적용가능성을 검증하였으며, 연구결과로 선정된 구성요소의 설계파라미터를 이용하여 시작차량을 제작하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1728-1732
• /
• 2005

Gear trains are used in many machinery for variable speed ratios. Typical shapes of gear trains are two categories: simple gear trains and planetary gear trains. Generally the methods of the design typical shapes are two way. One of the methods is trailblazing design and the other is selective design in available types. This paper presents the mechanism types when input rotating velocity and output rotating velocity are maintained for useful planetary gear reducers of twelve types. Also, this paper gives the applicable example about rotating velocity of the gear axis, carrier velocity and the organized gear specifications

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.912-913
• /
• 2015

자동차의 오토 기어를 능동적으로 제어하기 위해 전자기력을 이용한 원통형 선형 보이스 코일 전동기를 설계 하였다. 설계 시 유한 요소 해석 프로그램을 이용해 각 부품의 자기 포화 밀도 및 코일에 인가되는 자속을 계산하여 성능을 예측하였다. 기본모델에 대해 중량을 최소화한 모델을 제작하여 실험한 결과 추력은 기본모델과 비슷한 상태에서 중량이 약 40% 감소하였다.