• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.3
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• pp.320-326
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• 2015

Despite the wide industrial applications of planetary gear trains, the relationship between the design parameters (tooth profile, carrier mass, etc.) and performance (strength, vibration, noise, etc.) remains poorly understood. A significant amount of research has focused on transmission errors, which are measurable performance indicators directly related to the design parameters. Herein, an experimental test rig for a single-stage planetary gear set built using digital angular encoders and gap sensors is described. To study the static and dynamic characteristics of this planetary gear train, the transmission errors and sun gear orbit are analyzed from the data measured under various levels of torque and speed. The transmission errors of the gear train decrease 40% when the speed increases from 30 to 600 rpm with an output torque of 39.2 Nm, and increase 22% when the output torque increases from 19.6 to 39.2 Nm with an input speed of 30 rpm.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.1
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• pp.30-37
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• 2000

In this paper rapid prototyping and precision casting technology have been developed for the manufacturing of inlet gear box of an airplane, Rapid prototyping is a new prototyping technology that produces complicated parts directly from three-dimensional CAD data with a high efficiency and has been extensively applied to various manufacturing processes. In the present work Selective Lase Sintering(SLS) system is utilized in order to manufacture prototype of the inlet gear box. Prototyping technology using SLS is also investigated from the viewpoint of accuracy. Using the SLS master the casting products are manufactured through several processes such as : vacuum casting lost wax shell casting and investment cast-ing. The shrinkage characteristics of wax and cast iron in the casting procedures are considered and then reflected to the design procedure so that the accuracy of the product is improved consequently.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.3
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• pp.200-207
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• 2000

The analysis of interference and efficiency are important phases in the design of planetary gear train. Because most planetary gear trains contain internal gear called ring gear, interferences between ring gear and planet gear should be analyzed in the step of design and manufacturing. Addendum modification coefficient, pressure angle, speed ratio between ring gear and sun gear are governing factors for interferences. In this paper, the interferences of 2K-H I type planetary gear train based on various planetary gear trains are studied. As that results, the ranges of addendum modification coefficients which would not lead to interferences is analyzed. Based on these ranges, theoretical efficiencies are investigated as 6 configurations of 2K-H I type planetary gear train, which is based on basic efficiency, and optimal addendum modification coefficients which generate the maximum efficiency of planetary gear train are presented. To prove results of theoretical efficiency analysis, experimentations are performed.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.3
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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.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.41-44
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• 2009

A multi-stage gear mold including gears of 2mm and 1.5mm diameter was designed and machined in this research for developing micro gear mold manufacturing technology with micro endmill. Mechanical shapes having differential micro teeth were analyzed to be formed as designed and processing conditions were optimized by analyzing machined surface chip and cutting force. Based on the results, a prototype of micro multi-stage gear mold was manufactured.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.2
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• pp.32-39
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• 2009

This paper describes mathematical models of the torsional geared driving system for the indexing path and the mill driving path in a mill turret. The eigenvalue analysis for the models is conducted both with and without the gear contact stiffnesses. The natural frequency leads to the effect of gear contact stiffnesses on the vibration of torsional geared systems in a mill turret. It is necessary to analyze eigenvalues of the complex geared torsional system in order to prevent the unexpected vibrations.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.2
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• pp.42-48
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• 1997

Drive systems are composed of spiral bevel gear, axle and bearings. In this paper, drive systems and the part of them are analyzed and a correlation of the factor that shows the geometry of spiral bevel gear is evaluated. The Weibull distribution of probability for survival, which caused by the load of bearings and gear teeth, would be calculated, and the life and reliability with equivalent function could be measured more specifically. The reliability methods are applied as a probability of which the gear drive systems are satisfiably operated.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.2
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• pp.231-237
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• 2015

The pin-gear drive is a special form of fixed-axle gear mechanism. A large wheel with cylindrical pin teeth is called a pinwheel. As pinwheels are rounded, they have a simple structure, easy processing, low cost, and easy overhaul compared with general gears. They are also suitable for low-speed, heavy-duty mechanical transmission and for occasions with more dust, poor lubrication, etc. This paper introduces a novel slewing ring bearing with an external pinwheel gear set (e-PGS). First, we consider the exact cam pinion profile of the e-PGS with the introduction of a profile shift. Then, the contact stresses are investigated to determine the characteristics of the surface fatigue by varying the shape design parameters. The results show that the contact stresses of the e-PGS can be lowered significantly by increasing the profile shift coefficient.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.4
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• pp.135-141
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• 2008

Independent suspension axle and final reduction gear for special-purpose vehicles such as a armored vehicles are almost imported in Germany etc. so, developing them is necessary to save cost. In severe condition (open fields, water surface driving, obstacle pass), special-purpose vehicles must work well. Drop box, axle and final reduction gear performed static analysis. We know that is possible weight reduction. The purpose of this paper is to find out the optimal shape of final reduction gear's case by means of response surface methodology. The response surface method is the statistical method which can be applied to the non-sensitivity based optimization. The response surface which is constructed by the least square method contains only the polynomial terms so that the global maximum and minimum points are easily obtained.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.3
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• pp.96-102
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• 1997

Eigenvalue analysis of vibration mode and an analysis by frequency response among the methods of predicting gear noise are related with transmitting sound of vibration. In this study we intended to reduce the vibration noise of differential gear by reducing torque fluctuation of drive pinion shaft which causes vibration noise of differential gear in rear wheel drive vehicles. For this we developed multi-degree of freedom analysis model in which mass moment of inertia and torsional spring combined and we examined the influence of torsional vibration of driveline elements by performing forced vibration analysis of engine excitation torque. We studied the methods for reducing torsional vibration of driveline according to the design factor of propeller shaft and examined the effects reducing vibration in differential gear by applying flexible coupling.