• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.5
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• pp.1-9
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• 1995

The purpose of this study is to develop a computer simulation program for analyzing load transmission characteristics of a helical gear system in design stage. In this analysis, the rotational delay, load distribution, root stress, and contact area are investigated. That is, the influence function of deflection is obtained by finite element analysis and the influence function of approach and gear tooth error are considered. Load distribution, rotational delay, and contact area are calculated by solving load-deflection equation which includes these influence functions and tooth error, and the influence function of the bending moment is obtained by finite element analysis. The root stress is calculated by the load distribution and the influence function of the bending moment. The results of the simulation are cross-checked through a specially designed experimental set-up.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.5
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• pp.8-14
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• 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 Advanced Marine Engineering and Technology
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• v.17 no.3
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• pp.80-87
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• 1993

The various configuration of thin-shaped bevel gears are used usually for such as main reduction gear of the hovercraft. But the reasonable and concise guide to thedesign of the se bevel gears is not yet obtained, since the tooth of bevel gear has complex form. The purpose of these investigation is to be establish the design guide and to propose the desirable configuration form for thin-shaped straight bevel gear. In this report, the desirable configuration is examined experimentally by clearing up the effect of web and rim thickness, rim support condition upon the load distribution and root stress distribution along the tooth trace. The results are summarized as follows. (1) The crowning of tooth trace exerts a significant effect on the root stress distribution of thin-shaped bevel gear. (2) As the desirable configuration of the thin-shaped bevel gear, it is to be recommended that the rim is supported at the heel side of tooth trace. (3) But, as special type, it is desirable that the rim is supported at the toe side.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.3
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• pp.116-121
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• 2012

In recent years, world is faced with a transportation energy dilemma, and the transportation is dependent on a single fuel - petroleum. However, Hybrid Electric Vehicle(HEV) technology holds more advantages to reduce the demand for petroleum in the transportation by efficiency improvements of petroleum consumption. Therefore, there is a trend that lower gear noise levels are demanded in HEV for drivers to avoid annoyance and fatigue during operation. And meshing transmission error(T.E.) is the excitation that leads to the tonal noise known as gear whine, and radiated gear whine is also the dominant source of noise in the whole gearbox. This paper presents a method for the analysis of gear tooth profile and lead modification, and the predictions of transmission error and load distribution are shown under one loaded torque for the 1st gear pair of HEV gearbox. The test is also obtained before tooth micro-modification under the torque. At last, the appropriate tooth modification is used to minimize the transmission error and load distribution under the loaded torque. It is a good approach which the simulated result is used to improve the design in order to minimize the radiation gear whine noise.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.5
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• pp.66-72
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• 2016

Gearboxes are mechanical components that transmit power by adjusting input and output speed and torque. Their design requirements include small size, light weight, and long lifespan. We have investigated the effects of carrier pinhole position error on the load sharing and load distribution characteristics of a planetary gear set with four planet gears. The simulation model for a simple planetary gear set was developed and verified by comparing analytical results with a putative model. Then, we derived the load sharing and load distribution characteristics under various pinhole position error conditions using the prototypical simulation model. The results showed that the mesh load factor and face load factor increased with the pinhole position error, which then influenced the safety factor for tooth bending strength and surface durability.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.6
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• pp.830-836
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• 2011

Most of pitch/yaw reducers consist of several planetary geartrains. Planetary geartrains make gearboxes to be small and light, low noise and good efficiency. Most important thing in the planetary geartrain is load distribution on the gear tooth flank. In this study, the effect of output shaft bearings on the load distribution of gear tooth flank has been investigated. The commercial software was employed to compare the load distribution of two models depending on the bearing type. The spherical roller bearing(SRB) and the cylindrical roller bearing(CRB) were used as output shaft bearings in the $1^{st}$ model, and two taper roller bearings(TRB) were used in the $2^{nd}$ model. As a result, it was found that the $2^{nd}$ model. showed better performances on the load distribution of gear tooth flank, this results stated that the output shaft bearing system could be important consideration when designing reducers for wind turbine systems.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1079-1081
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• 1999

This paper presents the standard for dividing/tieing the distribution lines and installing optimally the automated distribution switch-gear in multi-line faults. Also this paper recommends the distribution system design in consideration of the live load transfer of the concentrated load in the last load-side. This recommendation will be useful for designing the distribution network, developing the feeder automation software and operating the distribution automation system.

• Korean Journal of Agricultural Science
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• v.47 no.2
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• pp.327-335
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• 2020

The purpose of this study was to analyze the load distribution and contact safety factor for the power take off (PTO) gear of a 71 kW class agricultural tractor. In this study, a simulation model of the PTO gear-train was developed using Romax DESGINER. The face load factor and contact safety factor were calculated using ISO 6336:2006. The simulation time was set at 2,736 hours considering the lifetime of the tractor, and the simulation was performed for each PTO gear stage at the engine rated power conditions. As a result of the simulation, the face load factors for the driving gear at the PTO 1^st, 2^nd and 3^rd stages were 1.644, 1.632, and 1.341, respectively. The contact safety factors for the driving gear at the PTO 1^st, 2^nd and 3^rd stages were 1.185, 1.216, and 1.458, respectively. As the PTO gear stage was increased, the face load factor decreased, and the contact safety factor increased. The load distributions for all the PTO gears were concentrated to the right of the tooth width. This causes stress concentrations and shortens the lifespan of the gears. Therefore, it is necessary to improve the face load factor and the contact safety factor with macro-geometry and micro-geometry.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.1
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• pp.29-35
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• 2013

The pitch reducer consists of several planetary gearsets, and they should have good load distribution over gear tooth flank and load sharing among the planets to improve the durability. This work investigates how bearing internal clearances influence both the load distribution over the gear tooth flank and the planet load sharing. A whole system model is developed to analyze a pitch reducer. The model includes non-linear mesh stiffness of gears, non-linear stiffness of bearings. The results indicate that the face load factor and mesh load factor decrease, and the fatigue life of output shaft bearings increase as bearing internal clearances of output shaft decrease. Therefore, the internal clearance of output shaft bearing must be considered when designing the pitch reducer for wind turbines.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.10
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• pp.36-45
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• 1996

The precise estimation of the reliability and life of the Ravigneaux planetary gear train used in an automatic transmission is necessary in order to enable accurate material and geometric properties to reliability distrobution and the number of load cycles at failure. These are critical for the proba- bilistic design of complex planetary gear system as Ravigneaux type particularly during various gear ratios. The Ravigneaux planetary gear train has five gears, such as a forward and a reverse sun gear, a short and a long pinion, and an annulus gear. In this paper, the Ravigneaux gear system is analyzed to figure out the reliablity distribution. i.e. the probability of survival in the system without its overhaul. First, the reliablity method based on the Weibull distribution is used in conjuction with the Palmgren's model to predict both the individual reliabilities of its components and the nimber of load cycles when the system failed. Then using the presented method, the life of the Ravigneaux gear system can be determined. Alwo the different design parameters such as tooth face width, material property, and Weibull exponent are applied and reached to optimal ones. Thus, the precise evaluation of the reliability and life of the Ravigneaux planetary gear train used in an automatic transmission can be effectively carried out.