• 동력기계공학회지
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• 제17권5호
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• pp.128-137
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• 2013

Modern transmission technologies such as automated manual transmission(AMT) and dual clutch transmission(DCT) are interested to all manufactures due to their fuel efficiency and driver's convenience, especially in a hybrid system. AMT has advantages in that they have a high efficiency of manual transmissions(MT) and offer operation convenience similar to automatic transmissions(AT), but it has some disadvantages in that they have torque gap during gear shift and shift time. To reduce disadvantages, it is necessary to evaluate errors and characteristics as a developing simulation model before experimental verification. The purpose of this study is to develop virtual components and simulate the transient response of AMT. A dynamic AMT model and a control logic for an integrated vehicle model have been developed using Matlab/Simulink as a simulation platform. In this paper, the clutch model to describe the stick-slip transition mode and the transmission model to describe the neutral gear shifting is introduced and compared with each other.

• 한국정밀공학회지
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• 제16권12호
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• pp.99-108
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• 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.

• 한국자동차공학회논문집
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• 제22권1호
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• pp.77-84
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• 2014

The worm gear is used in the motor drive system of automotive CVVL because of its compactness and self-locking ability. A ZK worm and an involute helical gear can be meshed in order to reduce production cost. However, the gearing is not suitable for the reliability and the NVH problem. To improve the dynamic performances, an optimal design process is considered. The transmission error is calculated theoretically and minimized with the several gear design parameters. An inequality condition such as the teeth interference elimination is added.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 춘계학술대회 논문집
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• pp.399-403
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• 2002

The transmission system of high speed train serve in the severe condition compared with those of other trains, namely, they have to transmit high power to run with high speed and they have to make maximum use of the limited space. To clarify the strength of gear for Korea High-Speed Train, a bending fatigue test of gear specimen is performed and compare with actual gear's. From this result, specimen test is useful to infer S-N curve and endurance limit of actual gear that much time and expense are consumed.

• 융복합기술연구소 논문집
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• 제5권2호
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• pp.7-12
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• 2015

A novel topology for the magnet gear is proposed in this study. Differently from the existing methods, both sides of magnet array in this topology are used, resulting in increasing the efficiency of the mechanism. The closed magnetic path between the magnetic elements decreases the leakage flux, so the interlinking magnetic flux through the air-gap is focused and intensified. This paper discusses the dominant parameters of the proposed magnet gear influencing the resulting transmission torque. The parameters are designed from the sensitivity analysis using the commercial FEM analysis tool. And, the test setup for verifying the performance of the system is described.

• 한국자동차공학회논문집
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• 제5권2호
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• pp.13-22
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• 1997

Power flow characteristics of a hydro-mechanical transmission system(HMT) are investigated for tracked vehicle in steering. A HMT consisting of two hydrostatic pump motors(HST), several planetary gear trains and steer differential gear is considered. In order to obtain the direction and magnitude of the power flow of the HMT, network theory for the general power transmission is used. Network model for the HMT in steering is developed, which consists of shafts, nodes and transmission elements such as clutch, gear, etc. Power flow analysis procedure consists of two stages : (1) traction force analysis in steering, (2) power flow analysis in HMT. Torque and speed of every transmission element of the HMT is determined from the network analysis. Also, efficiency, mechanical and hydraulic power loss including HST, are obtained. In addition, the regenerative power flow resulting from steering can be studied in graphic display. The power flow analysis program(PCSTEER) developed in this work can be used as a useful design tool for the tracked vehicle with HMT.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.305-308
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• 2002

The mechanics, electronics and manufacturing technology have been developed rapidly. Nowadays vehicle stability becomes more and more important then ABS (Anti-lo7k Brake System), ASR (Anti-Slip Regulator), TCS, (Traction Control System), ESP (Electronic Stability Program), and VDC (Vehicle Dynamic Control) which actively control the vehicle stability actively has been improved. In this study, instead of automatic transmission, CVT (Continuously Variable Transmission) is used because of the continuously gear ratio changes. It can effectively transfer the torque from engine to tire more than other gear transmission. The modeling is simplified assuming that there are no resistance parameters.

• International Journal of Precision Engineering and Manufacturing
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• 제8권4호
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• pp.27-32
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• 2007

Gears, crucial components in modern precision machinery for power transmission mechanisms, are required to have low contacting noise with high torque transmission, which makes the use of gear-tooth profile modifications and gear-tooth surface crowning extremely efficient and valuable. Due to the shortcomings of current techniques, such as manual rectification, mechanical modification, and numerically controlled rectification, we propose a novel electrochemical gear-tooth profile modification method based on an artificial neural network control technique. The fundamentals of electrochemical tooth-profile modifications based on real-time control and a mathematical model of the process are discussed in detail. Due to the complex and uncertain relationships among the machining parameters of electrochemical tooth-profile modification processes, we used an artificial neural network to determine the required processing electric current as the tooth-profile modification requirements were supplied. The system was implemented and a practical example was used to demonstrate that this technology is feasible and has potential applications in the production of precision machinery.

• 대한기계학회논문집
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• 제11권6호
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• pp.1014-1025
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• 1987

본 연구에서는 기계요소중에서도 그 성능에 미치는 인자의 수가 많고 또 그 영향이 복잡하고 난해하며 아직도 경험적 요소가 수많이 남아있으면서도 공업적으로 매우 중요한 동력전달용 치차장치를 예로 들어 그 설계, 제작, 손상 및 트러블슈팅을 하기 위한 엑스퍼트시스템을 개발하려고 한다.

• International Journal of Automotive Technology
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• 제8권1호
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• pp.75-82
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• 2007

This paper presents practical work on the reduction of gear whine noise. In order to identify the source of the gear whine noise, transfer paths are searched and analyzed by operational deflection shape analysis and experimental modal analysis. It was found that gear whine noise has an air-borne noise path instead of structure-borne noise path. The main sources of air-borne noise were the two global modes caused by the resonance of an axle system. These modes created a vibro-acoustic noise problem. Vibro-acoustic noise can be reduced by controlling the vibration of the noise source. The vibration of noise source is controlled by the modification of structure to avoid the resonance or to reduce the excitation force. In the study, the excitation force of the axle system is attenuated by changing the tooth profile of the hypoid gear. The modification of the tooth profile yields a reduction of transmission error, which is correlated to the gear whine noise. Finally, whine noise is reduced by 10 dBA.