• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.29 no.1
• /
• pp.37-44
• /
• 2016

This study is concerned with the numerical investigation of dynamic characteristics of 2.5MW-class wind turbine gearbox in which the misalignment improvement of plenary gear shafts by the flexible pins and the dynamic impact response are analyzed by the finite element method. The tooth contact between gears is modelled using the line element having the equivalent tooth stiffness and the contact ratio to accurately and effectively reflect the load transmission in the internal complex gear system. The equivalent tooth stiffness is calculated by utilizing the tooth deformation analysis and the impulse torque is applied to the input shaft for the dynamics response characteristic analysis. Through the numerical experiments, the equivalent tooth stiffness model was validated and the misalignment improvement of planetary gear shafts was confirmed from the comparison with the cases of fixed shafts at one and both ends.

• Journal of Advanced Marine Engineering and Technology
• /
• v.34 no.6
• /
• pp.806-815
• /
• 2010

Gear trains are combined with the planetary gear units and helical gear units. It is known that the combination type is decisive to the system performances of the transmissions. In this paper, within the commonly used range of the design requirements for medium and large scaled (1~8 MW) wind turbines, the transmission characteristics of the typical layouts of the gear train are investigated. According to the international standard by ANSI/AGMA/AWEA 6006-A03, the gear boxes are basically designed and compared with respect to the system lifes of 99% reliability, total weight, the power densities, overall diameter/length and the maximum stresses of the gear teeth. With these comparison works, the characteristics of the layouts of gear trains are discussed.

• Journal of the korean Society of Automotive Engineers
• /
• v.3 no.2
• /
• pp.1-9
• /
• 1981

자동차가 실용화된 이래 성능을 더욱 향상시키고 그 조작을 더욱 간편하게 하기 위하여 각종의 개량 개발이 거듭되고 가지가지의 신안이 이루어져서 오늘날 자동차 각부의 기구를 살펴볼 때 그 정교함에 놀라지 않을 수 없는 흥미있는 것들이 많다. 그 중의 하나로 자동변속기를 들수 있다. 자동변속기에도 여러가지의 종류가 있으나 오늘날 그 대종을 이루고 있는 것은 유체클러치 또는 토오크 컨버어터와 압력에 의해서 자동조작되는 유성치차장치의 조합으로 구성된 것이다. 그러므로 이들 자동변속기의 기능을 알기 위해서는 유성치차장치의 변속기구에 대한 이해가 필수적이나, 이에대한 상세한 설명이 나와있는 문헌이 국내외적으로 드물어서 이 분야에 관심 있는 사람들이 많은 어려움을 겪을 것으로 생각되어, 이하 이에 대한 해설을 해보려고 한다.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.19 no.3
• /
• pp.605-614
• /
• 1995

In the automatic transmission using planetary gear there exists nonlinearities due to the finite difference between gear ratios, which yield torque hole during shift and influence on the ride quality and life of clutch. Based on the reaction carrier and converter turbine speed sliding functions are defined. Nonlinear closed-loop control laws are derived using them. Computer simulation shows that the closed loop design is better than the open loop design and semi-closed loop design.

• International Journal of Automotive Technology
• /
• v.7 no.3
• /
• pp.315-320
• /
• 2006

We have developed an active front steering system(AFS) with a planetary gear train, which can vary the steering gear ratio according to the vehicle speed and improve vehicle stability by superimposing steering angle. We conducted vehicle tests showing that co-operated control of AFS with ESP can improve vehicle stability by direct control of tire slip angle and that steering reaction torque during AFS intervention can be compensated by torque compensation using electric power steering.

• Journal of the Korean Society for Precision Engineering
• /
• v.30 no.11
• /
• pp.1187-1192
• /
• 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.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.06a
• /
• pp.387-390
• /
• 2007

The gearbox for wind turbine have been increased the size by the wind turbine is needed to produce bigger power. The optimal sizing for gearbox is demanded because of limited space on the nacelle. The volume and weight for the gearbox are influenced especially for size of it. Therefore, the purpose of this study investigates the design characteristics considering types of gear train structure for optimizing the volume and weight of the gearbox.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.12 no.6
• /
• pp.1312-1319
• /
• 1988

Internal gear is the important part of the planetary reduction gear system. This study aims at developing the numerical analysis method for design of spherical hob to manufacture internal gear. Methods of calculation of hob tooth profile, generating tooth profile and tooth profile errors such as the errors of pressure angle, tooth thickness and pitch of spherical hob must be made smaller than those of standard tooth profile. And, the smaller the pressure angle and the number of equivalent pinion tooth become, the larger the tooth profile errors are. One design example of spherical hob is proposed.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.13 no.5
• /
• pp.8-14
• /
• 2014

A slewing reducer consists of two planetary gearsets which require a good load distribution over the gear tooth flank for enhanced durability. This work investigates how the bearing characteristics influence the load distribution over the gear tooth flank. A complete system model is developed to analyze a slewing reducer, including the non-linear mesh stiffness of the gears and the non-linear stiffness of bearings. The results indicate that the type, arrangement and preload of the output shaft bearings greatly influence the gear mesh misalignment, contact pattern, face load factor, gear safety factor and lifetimes of the parts.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.17 no.2
• /
• pp.95-102
• /
• 2018

This paper presents the development of the transfer case for a 3.5-ton commercial vehicle. A transfer case is composed of many parts, including helical gear, shaft, bearing, planetary gear, and others. Helical gears are currently used as power transmitting gears due to their relatively smooth and silent operation, large load carrying capacity, and operation at higher speeds. The key parameter in transfer case development is the bending stress at the root of a tooth in the helical gear. The bending stress of the helical gear has been studied through theoretical calculation and finite element method (FEM) analysis. Major factors of the bending stress calculation are determined according to American Gear Manufacturers Association (AGMA) standards, and FEM model analysis of the helical gear is conducted. FEM results are compared with theoretical calculations and the difference of the bending stress is described.