• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.15 no.2
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• pp.61-66
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• 1979

Skipjack, Katsuowonus vagans, yellow tail Seriola quinqueradiata and Scomberomorus sinensis are largely caught by trolling gear in the coastal waters of Jeju Island. The author determined the hydrodynamic resistance of the trolling gears uscd in the waters, estimated the pulling force of the fish species above mentioned by use of body weight, and then calculated the minimum diameter of the lines of trolling gears. The results obtained are as follows: 1. The hydrodynamic resistance of the trolling gears present linear relationship in accordance with the towing speed of the gears. 2. The diameter of seizing leader, leader gut and branch line used in the waters might be durable to catch skipjack and yellow tail, whereas the diameter of those must be weak in intensity for Scomberomorus zinensis.

• Structural Engineering and Mechanics
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• v.43 no.4
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• pp.439-448
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• 2012

This paper investigates the load sharing of double circular arc helical gears considering the influence of assembly errors. Based on a load sharing formulae, a three-dimensional finite element tooth contact analysis (TCA) is implemented with commercial software package ANSYS. The finite element grid for the double circular arc gear contact model is automatically generated by using the APDL (ANSYS Parameter Design Language) embedded in ANSYS. The realistic rotation of gears is achieved by using a coupling degree-of-freedom method. Numerical simulations are carried out to exemplify the proposed approach. The distribution of contact stress and bending stress under specific loading conditions are computed and compared with those obtained from Hertz contact theory and empirical formulae to demonstrate the efficiency of the proposed load sharing calculation formulae and TCA approach.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.12
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• pp.2695-2702
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• 2002

The elevator gear box with the helical gears needs to be developed instead of the one with the worm gears to improve the efficiency. In order to develop the gear box, the analytical tool to predict the helical gear noise is necessary to meet customer's noise requirement. Gear noise is related to the loaded transmission error. Therefore, the simulation program fer the loaded transmission error analysis of the helical gears is developed in this study. Using the developed program, the effects of tooth modification such as tip relief and the extent of tip relief are investigated. Finally, the procedures to determine the tip relief and the extent of tip relief are proposed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.4
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• pp.59-65
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• 2010

This paper presents the study on the contact stress analysis of a pair of mating spur gears during rotation. Contact stress analysis is performed between two spur gear teeth at different contact positions during rotation. An example is presented to investigate the variation of contact stress on a pair of mating gears with contact positions. The variation of contact stress during rotation is compared with the contact stress at lowest point of single tooth contact(LPSTC) and AGMA Equation for contact stress. The results show that contact stress varies along the contact position and gets maximum values in the beginning and end of the contact. In this study, the gear design considering the contact stress on a pair of mating gears is more severe than that of AGMA standard.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.1015-1019
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• 1997

In this study, the forging process of spur gears has been investigated. The forging peocess of spur gears has been classified into two type of operations, guiding one and clamping one in this investigation. Two type forgings of spur gears have been analysed by using upper bound method. The predicted values of the forging load were compared with those obtained from the forging experiments. The forging experiments were carried out with a commerial aluminium alloy. The forged parts obtained through the guiding type forging were campared with those obtained through the clamping type forging.

• Journal of the Korean Society for Precision Engineering
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• v.9 no.4
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• pp.78-89
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• 1992

The most important criteria of quality of meshing and contact of gears are the low level of noise and the sufficient dimensions and location of the contact. A new approach for determination of machine-tool settings for spiral bevel gears is proposed. The proposed settings provide a function of transmission errors, the desired location and orientation of contact. The function is able to absorb piece-wise linear functions of transmission errors that are caused by the gear misalignment and to reduce the gear noise. The determination of pinion machine-tool settings is based on the local synthesis of gears. A computer program for simulation of meshing bearing contact and determination of transmission errors for misaligned has been developed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.391-392
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• 2006

Gears are essential and useful elements which power is transmitted from a source to a driven equipment. Therefore, it is very important to design gears correctly. Two important points in the gear design procedures are capacities of the gears's bending strength and pitting resistance. This paper deals with two subjects about spur and helical gears : analyzing for strength and wear capacities, and design of face width. Also, this paper proposes the analytical program which is developed for computer aided design and analysis This program is based on the American Gear Manufactures Association(AGMA) Standards.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.6
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• pp.148-159
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• 1999

A numerical method is presented for the dynamic analysis of spur gears rotating with very high angular speeds. For an efficient computation each gear is assumed to consist of a rotating rigid disk and an elastic tooth having mass, and finite element formulations are used for the equations of motion of the tooth. The geometric constraint is imposed between the rigid disk and the elastic tooth to fix them, and contact condition is imposed between the meshing teeth of the gears. At each iteration of each time step the Lagrange multiplier and contact force are revised by using the constraint error vector, and then the whole equations of motion are time integrated with the given Lagrange multiplier and contact force. For the accurate solution the velocity and acceleration constraints as well as the displacement constraint are satisfied by the monotone reductions of the constraint error vectors. Computing procedures associated with the iterative schemes are explained and numerical simulations are conducted with the spur gears.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.169-174
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• 2000

This paper is about automatic design of measuring master gears. Master gears are usually thought of as gears of extreme accuracy level, but are better defined as gages to check the meshing action of production gears. This is usually not recognized because most mechanical gages are associated with static measurements rather than having the form of machine elements used in a functional check involving machine motion. In this paper the interface that allows beginners to design easily and quickly is provided. The addition and modification of data is easy and the reduced design lead time is feasible with the program even though users don't know much about program since it is developed with Visual Lisp and DCL.

• Journal of Biosystems Engineering
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• v.27 no.5
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• pp.371-380
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• 2002

The objectives of this study were to analyze gear rattle in a power drive line using its dynamic model and to derive design guidelines to eliminate it. A 72 degrees of freedom model of power driveline of an agricultural tractor was developed and proved to be valid fer predicting the collision characteristics of gears in mesh, which may determine whether or not the gear rattle will occur. Using the model the effects on the rattle of drag torque, backlash, mass moment of inertia, transmitting torque were analyzed. Increasing drag torque or decreasing mass moment of inertia reduced gear rattle. The gears transmitting power do not develop rattles. It was also found that a large amount of rattle is likely to be developed by the change gears placed at the end of idle shafts. Increasing the drag torque to such change gears may be the most effective way of reducing the gear rattle in a tractor driveline.