• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.2
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• pp.44-50
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• 2006

A driver's feelings of transmission serve as a basis to judge not only the transmission but also the entire automobile that he or she drives. The importance of transmission feelings is increasing daily because of driver's desire for increased torque and other improved functions. In order to accommodate such desire of drivers, new friction materials have been developed. The study in this report compared the affects of such materials and the force for transmission theoretically and empirically. By doing so, the study attempted to establish basic references for computation of capacity and other factors to be determined at the time of design of synchronizer system.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.8
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• pp.156-164
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• 2014

In a delay line type of a time-to-digital converter implemented in Field Programmable Gate Array, the timing accuracy decreases for a longer carry chain. In this paper, we propose a structure that has a multi-phase clock and a state machine to check metastability; this would reduce the required length of the carry chain with the same time resolution. To reduce the errors caused by the time difference in the four delay lines associated with a four-phase clock, the proposed TDC generates a single input pulse from four phase clocks and uses a single delay line. Moreover, the state machine is designed to find the phase clock that is used to generate the single input pulse and determine the metastable state without a synchronizer. With the measurement range of 1 ms, the measured resolution was 22 ps, and the non-linearity was 25 ps.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.3
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• pp.373-378
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• 2013

The speed change performance of transmissions has become a serious issue because of the increase in the inertia moment that has accompanied increases in engine output and transmission size. Therefore, it is necessary to develop better wear resistant friction materials. In this study, an appropriate sintered friction component for the synchronizer ring of a diesel manual transmission was developed, and its bonding characteristics were analyzed. That is, a process for bonding an Fe-based base material and Cu-based sintered friction material was developed. BSE and EDX analyses of this bonding layer were conducted, along with a shear strength test, to determine the bonding characteristics.

• Journal of Auto-vehicle Safety Association
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• v.4 no.1
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• pp.23-26
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• 2012

본 논문은 듀얼클러치 변속기 변속 메커니즘 개발을 위한 동역학적 시뮬레이션 해석 및 피로수명 해석에 관한 연구이다. 캠을 이용한 쉬프트 포크의 이송으로 기어를 변속하는 개념을 갖는 쉬프트 메커니즘의 작동성 및 설계안 검증을 위해 캠의 회전 속도, 접촉면의 경계조건 및 싱크로나이저 슬리브에서의 저항을 반영한 모델링을 구성하여 동역학적 시뮬레이션을 실시하였다. 각 파트의 응력 및 변형률 발생을 해석하여 설계 개선안을 도출하고, 개선안이 반영된 최종 시작모델의 시뮬레이션 상 최대 응력 발생 시점에서 시프트 포크의 각 접촉면 별 외력 작용을 분석하여 이를 적용한 피로 해석을 진행하였다.

• Tribology and Lubricants
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• v.24 no.6
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• pp.285-290
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• 2008

The purpose of this paper is to present the case study of tribological failure analysis on the gear damages, oil leakage, and sealant sealing in a manual transmission of front engine and front wheel drive vehicle. The manual transmission is to change the speed range and direction of the engines depending on the driving conditions by friction driving forces with input and output gear system. The material property and surface roughness of the gears are strongly related to the gear noise and micro-vibration, oil leakage and wear, which may decrease the real contact area of the gear and the strength of the oil film thickness between the driving gear and driven one. The O-ring damage of speedometer driven gear and bad sealant sealing of oil pan may produce oil leakage through the contact surfaces, which cause the oil shortage and seizure on the sliding surfaces of the transaxle gears. In the failure case study, the proper repair working and good lubrication are very important for the long life of the transaxle without any tribological failures and oil leakage.