• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.22 no.4
• /
• pp.358-364
• /
• 2012

This work dealt with dynamic characteristics of spur gear and helical gear system to understand the gear vibration and noise. To find out dynamic characteristics in the gear system, a finite element model and an analytic model for the gear system were used. Using the models, the natural frequency and mode-shape characteristics of spur gears and helical gears were calculated. Two models show that natural frequencies of helical gears were lower than those of spur gears. Mode-shape characteristics of gear pairs by analytical model and some issues of finite element modeling were also discussed. Impact test was used to validate the finite element model.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.13 no.1
• /
• pp.48-54
• /
• 2004

This paper describes the development of automatic shape design program for spur gear. It produces automatically third-dimensional surface and solid model used in CAD/CAM system with inputting simple measurements. This program can maximize user's convenience and get surface and solid model quickly as accepting GUI(graphic user interface). Automatic shape design program for spur gear was developed by Visual LISP, a developer program. Besides, a geometrical method and a mathematical algerian are used in this program. Use frequency of a fine spur gear is on the increase recently and manufacture process of this gear is heat treatment after press processing with molding. In this press processing, the upper punch portion of a fine spur gear shape is drafted by CAM. Therefore, estimated that surface and solid model of spur gear used to CAM are needed in this research. In this research, after 2 ㎜ gear was modeled by auto shape design program, the upper punch portion of a fine spur gear was manufactured as giving third-dimensional model to CAM software and then, displayed the result as applying to press process.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.3 no.1
• /
• pp.198-206
• /
• 2000

The transmission load of gear devices is important factor in the design of gear system. To design gear system precisely, an analysis and calculation methods for transmission load of gears are demanded. The purpose of this study is to develop a computer program for analyzing tooth load sharing of a spur gear system by means of the contact theory. In this paper, load transmission characteristics is identified with elastic contact problem which is assumed to quasi-static equilibrium. The modeling of spur gear tooth is accomplished by application of I-DEAS.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.334-339
• /
• 2000

In order to predict the noise of the spur gear system, a simplified model of spur system including the housing is studied. The spur gear is modeled as a single degree of freedom system. The shaft-housing system is modeled as a clamped circular plate connected with a beam. The moment components of the beam excited by the spur gear mesh force are considered in the calculation of plate vibration and radiated noise. The out-of-displacements of the clamped circular plate due to the r-direction moment and ${\theta}$-direction moment are calculated. Radiated noise from the plate in the air is also calculated using Rayleigh integral. Using the numerical example, the numerical validation of the analytical procedure on the noise prediction are given.

• Proceedings of the KSME Conference
• /
• 2004.11a
• /
• pp.136-141
• /
• 2004

The gear in various mechanical components easily occurs at damages by the external torque. The main failure modes of the gear are surface pitting with the tooth surface and breakage with tooth root by caused fatigue. Therefore, the gear is very important role in the reliability research since it may cause fatal damage of entire system such as the gear box in automobile transmission. In this study, the failure mode of the gear was analyzed and accelerated durability analysis was employed for the life estimation of spur gears. In the case of assumed load spectrums, the reliability of spur gears was evaluated by inverse power law-Weibull accelerated life test model with cumulative damage exposure.

• Structural Engineering and Mechanics
• /
• v.53 no.4
• /
• pp.819-831
• /
• 2015

In this paper, we propose a new method for taking into account uncertainties based on the projection on polynomial chaos. The new approach is used to determine the dynamic response of a spur gear system with uncertainty associated to gear system parameters and this uncertainty must be considered in the analysis of the dynamic behavior of this system. The simulation results are obtained by the polynomial chaos approach for dynamic analysis under uncertainty. The proposed method is an efficient probabilistic tool for uncertainty propagation. It was found to be an interesting alternative to the parametric studies. The polynomial chaos results are compared with Monte Carlo simulations.

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.2
• /
• pp.171-176
• /
• 2002

This paper is the study on stress analysis of spur gear using a finite element method. Gear drives constitute very important mechanisms in transmitting mechanical power processes compromising several cost effective and engineering advantages. The load transmission occurred by the contacting surfaces arises variable elastic deformations which are being evaluated through finite element analysis. The automatic gear design program is developed to model gear shape precisely. This gear design system developed was used by pre-processor of FEM packages. The distribution of stresses at contacting surfaces was examined when a pair of gear contact.

• Journal of the Korean Society of Industry Convergence
• /
• v.9 no.4
• /
• pp.269-276
• /
• 2006

Strength Design method for involute spur gears is developed. The developed gear strength design system can design the optimized gear that minimize the number of pinion teeth with face tooth. Method of optimization is matrix form which is developed from this study. Design variables are transmitted power, gear volume, gear ratio, allowable contact stress and allowable bending stress, etc. Gear design method developed this study can be apply to the gears of plants, machine tools, automobiles.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.12
• /
• pp.99-108
• /
• 1999

A four-degree-of-freedom non-linear model with time varying mesh stiffness has been developed for the dynamic analysis of spur gear trains. The model includes a spur gear pair, two shafts, two inertias representing load and prime mover. In the model, developed several factors such as time varying mesh stiffness and damping, separation of teeth, teeth collision, various gear errors and profile modifications have been considered. Two computer programs are developed to calculate stiffness of a gear pair and transmission error and the dynamic analysis of modeled system using time integration method. Dynamic tooth and mesh forces, dynamic factors are calculated. Numerical examples have been given, which shows the time varying mesh stiffness ha a significant effect upon the dynamic tooth force and torsional vibrations.

• Journal of Mechanical Science and Technology
• /
• v.20 no.7
• /
• pp.941-949
• /
• 2006

Nonlinear behavior analysis was used to verify whether a one-way clutch is effective for reducing the torsional vibration of a paired spur gear system under periodic excitation. The dynamic responses were studied over a wide frequency range by speed sweeping to check the nonlinear behavior using numerical integration. The gear system with a one-way clutch showed typical nonlinear behavior. The oscillating component of the dynamic transmission error was reduced over the entire frequency range compared to a system without a one-way clutch. The one-way clutch also eliminated unsteady continuous jump phenomena over multiple solution bands, and prevented double-side contact, even with very small backlash. Installing a one-way clutch on both sides of the gear system was more effective at mitigating the negative effects of external periodic excitation and various parameter changes than a conventional gear system without a one-way clutch.