An improved design of power-cycling hydrodynamic mechanical transmission

Xiaojun Liu,Dongye Sun 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.8

Recent studies have demonstrated that the power-cycling hydrodynamic mechanical (PCHM) transmission has excellent performance in improving power performance and fuel economy of a wheel loader. However, these results have been obtained by assuming that its speed ratio can always change continuously. Hence, this study first investigated the speed ratio of the transmission how to change when shifting from one gear to another. It was found that the concept of the PCHM transmission suggested in the literature is ineffective, even for a configuration with two gears in the gearbox. Then, the configuration of the PCHM transmission was developed as a different one to increase the torque multiplication capacity and efficiency of the transmission. A design method for this transmission is proposed to quantify its performances. The design method is based on a multi-objective optimization problem which is comprised of two objectives, seven design variables and eleven constraints. The relationships between average efficiency of the transmission and maximum tractive force of the vehicle and the seven transmission parameters are qualitatively examined. Results show that the performance of the transmission depends mainly on the number of transmission gears instead of on three parameters of the torque converter. The average efficiency is not sensitive to the maximum tractive force on a globally optimal Pareto front. The PCHM transmission with the new configuration can enable the average efficiency and the maximum tractive force to increase by 2.1 % and by 6.6 %, compared to that of the traditional hydrodynamic mechanical transmission, respectively.

The Paradox of Productivity and Transmission Mechanism of Productivity

Byung Gwun CHOY(최병권) 한국혁신학회 2019 한국혁신학회지 Vol.14 No.4

본 논문은 생산성의 전달기구를 설정하여 생산성 역설 논쟁을 분석하려는 제3의 견해이다. 생산성 전달기구와 이 전달기구를 중심으로 만들어진 연립방정식 모형에서 digital transformation에 대한 투자가 생산성에 미치는 효과를 분석하였다. 추정결과 첫째, 생산성 전달과정의 불연속이 생산성 역설의 원인이 될 수 있음을 발견하였다. 특히 digital transformation과 노동자의 재교육 과정의 단절이 생산성 역설을 유발할 수 있음을 계량적으로 확인하였다. 둘째, digital transformation 투자, 인적자본, 노동자의 교육 및 재교육, 경제성장, 생산성 변수 등 생산성 전달기구 중심으로 구성한 연립방정식모형 추정에서 digital transformation 투자가 생산성에 미치는 통계적으로 신뢰할 수 있는 효과를 발견할 수 없었다. 따라서 본 논문은 2018년 러시아에서 생산성 전달과정의 불연속으로 digital transformation 투자에 대한 생산성의 역설을 발견하였다. By building the transmission mechanism of productivity, this paper analyzes the effect of investment in digital transformation on productivity. The productivity estimation model is established as simultaneous equations system centered on this transmission mechanism. First, this paper finds that discontinuities in the productivity transmission mechanism can cause productivity paradoxes. In particular, it is confirmed econometrically that the cut off of digital transformation and worker education processes could cause productivity paradoxes. Second, it is not possible to find the statistically reliable effect of digital transformation investment on productivity in estimating the simultaneous equation model composed mainly of productivity transmission mechanism such as digital transformation investment, human capital, worker education and reeducation, economic growth, and productivity variables. Therefore, this paper finds the productivity paradox for digital transformation investment in Russia in 2018 due to the discontinuity of the productivity transmission mechanism.

AMT용 새로운 변속자동 메커니즘 설계 및 해석

김정윤(Jungyun Kim),김기대(Gidae Kim) 한국산업경영시스템학회 2011 한국산업경영시스템학회지 Vol.34 No.4

This article proposes a novel shift automation mechanism for an automated manual transmission (AMT). The development of an automated manual transmission is currently being paid considerable attention by vehicle manufacturers, with the prospects of combining the comfort of an automatic transmission and the high efficiency of a manual transmission. In order to automate the shift mechanism of a manual transmission, the proposed shift automation mechanism consists of two electric motors, cross shaped pinion gears, rack type shift rails, and a ball splined hollow shaft. First we describe the shift mechanism and operating principles of a manual transmission to investigate important design criteria for the shift automation device. And a new shift automation mechanism is described with its structure, elements, and operating principles in detail. Using a conventional manual transmission, we develop a full three-dimensional CAD model of an AMT which includes main components of the manual transmission and the designed shift automation mechanism. Finally we investigate the operating performances and feasibility of the designed AMT by a dynamic analysis.

A Study on the Transmission-tribology Design Based on Existing Problem of the Gear Drive and Tribology

Lyu, Sung-Ki,Lu, Long,Wei, Yun-Long Korean Society for Precision Engineering 2006 International Journal of Precision Engineering and Vol.7 No.2

We propose a new concept of transmission-tribology design based on the investigation of development and existing problems of the gear drive and tribology. The content of transmission-tribology and transmission-tribology design is probed. Some effective methods of transmission-tribology design is probed. Some effective methods of transmission-tribology design are put forward. Partial achievements in this research are introduced tersely. Mechanical transmission, which is represented by the gear drive, and tribology are two main branches of mechanical engineering. They have their own definite research field. In recent years, we have been doing our utmost to suggest combining mechanical transmission-tribology and transmission-tribology design. Partial achievements in this research area are obtained.

The Paradox of Productivity and Transmission Mechanism of Productivity

최병권 한국혁신학회 2019 한국혁신학회지 Vol.14 No.4

By building the transmission mechanism of productivity, this paper analyzes the effect of investment in digital transformation on productivity. The productivity estimation model is established as simultaneous equations system centered on this transmission mechanism. First, this paper finds that discontinuities in the productivity transmission mechanism can cause productivity paradoxes. In particular, it is confirmed econometrically that the cut off of digital transformation and worker education processes could cause productivity paradoxes. Second, it is not possible to find the statistically reliable effect of digital transformation investment on productivity in estimating the simultaneous equation model composed mainly of productivity transmission mechanism such as digital transformation investment, human capital, worker education and reeducation, economic growth, and productivity variables. Therefore, this paper finds the productivity paradox for digital transformation investment in Russia in 2018 due to the discontinuity of the productivity transmission mechanism.

NOVEL SELF-CLAMPING CLUTCH MECHANISM FOR MICRO ELECTRIC VEHICLE TRANSMISSION

Seung-uk Park,김경웅,나병철,Jin-yong Kim 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.1

This paper deals with a novel clutch mechanism for transmission applications, which aims at easy application of the transmission as the micro-electric vehicle models expand in variety. The new mechanism actuated by the torque and rotational inertia of the traction motor instead of the conventional hydraulic or electronic actuator and features a simple structure compared to the conventional mechanism. The operating principle, structure and mathematical modeling of the new clutch mechanism are presented, and verification of mathematical modeling was done through comparison of experimrntal and analytical results. To investigate the automotive suitability of the new clutch mechanism, the shift characteristics are analyzed by longitudinal directional vehicle dynamic model applying new clutch mechanism. As a result of the analysis, it was confirmed that the shift shock absorbing ability and required time for shifting are applicable to the vehicle transmission.

A study on the transmission-tribology design based on existing problem of the gear drive and tribology

Sung-Ki Lyu,Long Lu,Yun-Long Wei 한국정밀공학회 2006 International Journal of Precision Engineering and Vol.7 No.2

We propose a new concept of transmission-tribology design based on the investigation of development and existing problems of the gear drive and tribology. The content of transmission-tribology and transmission-tribology design is probed. Some effective methods of transmission-tribology design is probed. Some effective methods of transmission-tribology design are putforward. Partial achievements in this research are introduced tersely. Mechanical transmission, which is represented by the gear drive, and tribology are two main branches of mechanical engineering. They have their own definite research field. In recent years, we have been doing our utmost to suggest combining mechanical transmission-tribology and transmission-tribology design. Partial achievements in this research area are obtained.

Design of Neural Networks Model for Transmission Angle of a Modified Mechanism

Yildirim Sahin,Erkaya Selcuk,Su Siikrii,Uzmay ibrahim The Korean Society of Mechanical Engineers 2005 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.19 No.10

This paper discusses Neural Networks as predictor for analyzing of transmission angle of slider-crank mechanism. There are different types of neural network algorithms obtained by using chain rules. The neural network is a feedforward neural network. On the other hand, the slider-crank mechanism is a modified mechanism by using an additional link between connecting rod and crank pin. Through extensive simulations, these neural network models are shown to be effective for prediction and analyzing of a modified slider-crank mechanism's transmission angle.

Analysis on the Shifting Mechanism of the Multi-link CVT

김정윤 한국자동차공학회 2023 한국 자동차공학회논문집 Vol.31 No.11

In this paper, the shifting mechanism of Khan Workholding’s continuously variable transmission(Khan CVT) has been simulated by using ADAMS, a multi-body dynamics analysis software. Khan CVT is composed of an input module of a crank structure, a shifting module of four pairs of two four-bar mechanisms, and an output module consisting of four one-way clutches and a simple planetary gear. It is designed to be compact and lightweight. Input power drives the first four-bar loop, and the output shaft is driven by the four one-way clutches that are connected to the second loop. Since one rotation of the crank shaft leads to a reciprocating motion of each pair of multi-links, the number of strokes of one-way clutches is determined by input speed. To determine the shifting mechanism, a detailed kinematic analysis was performed. Speed relations for the repetitive motions of each four-bar loop due to changes in link length have been derived by using a complete geometric description of the two four-bar mechanisms. Based on the CAD model, a numerical model has been built by using ADAMS that can simulate the shifting mechanism and performance of the Khan CVT. Finally, the speed and torque relations of each component derived in the kinematic analysis were investigated.

자동변속기용 2펌프 시스템 개발

홍명철(Myungchul Hong),이흥규(Heungkyu Lee),이륙(Ryuk Lee),황현수(Hyunsoo Hwang),김태준,김홍민(Hongmin Kim) 한국자동차공학회 2015 한국자동차공학회 학술대회 및 전시회 Vol.2015 No.11

Although oil pump is essential part to produces oil flow to the transmission components, over-design of the oil pump causes power loss in automatic transmission. By using optimized oil pump displacement with 2 pump system which has mechanical oil pump and electric oil pump can reduce power loss of automatic transmission. This paper introduces development process of 2 pump system and proposes how to increase the transmission efficiency with 2pump system in automatic transmission.