• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.3
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• pp.278-286
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• 2015

The effects of the main bearing stiffness combined with vertical non-torque force on the input load and shaft deflection of a gearbox were investigated for the three-point suspension drive train of a wind turbine. A finite element analysis model for the drive train was studied experimentally, and its applicability to the present study was verified. The results show that, as the main bearing stiffness is increased, the input load of the gearbox decreases, whereas the input shaft deflection increases. The stiffness component for the pitch moment has the largest influence on the gearbox input load. Although the gearbox life increases at a higher main bearing stiffness, the economic efficiency and durability of the entire drive train system should also be considered in the selection of the main bearing stiffness.

• Journal of Biosystems Engineering
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• v.26 no.5
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• pp.423-430
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• 2001

The purpose of this study is to develop high-speed rotary tillage system for a power tiller by improving the rotary blade and the power train of transmission. Mechanical structure of gear train of rotary drive of conventional power tiller was simplified so that power can be transmitted directly from second shaft to tilling speed change shaft by rotating freely the transfer gear which changes the direction of rotation of shafts using needle bearing installed into middle shaft. A new gear train suitable for the single-edged rotary blade and high-speed rotary drive was developed with the rotational speed of rotary shaft faster than 7.5% at 1st-speed and 1.4% at 2nd-speed the one of conventional system by changing the numbers of teeth of gears of middle shaft, tilling speed change shaft and PTO shaft. Using the developed gear train for high-speed rotary drive, field tests were performed to compare tillage performances by the developed single-edged blade and by the conventional double-edged blade. The results showed that the performances by the single-edged blade compared with the one by the double-edged blade was improved about 18% in field capacity, about 34% in fuel consumption, and 9.4% in soil crushing ratio. Therefore, it may be concluded that tillage performance by the single-edged blade was improved compared to the one by the conventional blade. Evaluation of the developed system consisting of single-edged blade and gear train for high-speed rotary drive in field revealed that tillage performance of the developed system was similar to the one of field test conducted using the system consisting of single-edged blade and gear train for rotary drive of conventional power tiller However, considering the higher cone index of the upland field where evaluation was carried out compare to the one of the ordinary paddy field, it may be concluded that tillage performance of the developed rotary tilling system better than the one of conventional system.

• Tribology and Lubricants
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• v.37 no.2
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• pp.48-53
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• 2021

Wind energy is considered as the most competitive energy source in terms of power generation cost and efficiency. The power train of the pitch drive for a wind turbine uses a 3-stage complex planetary gear system in being developed locally. A gear train of the pitch drive consists of an electric or hydraulic motor and a planetary decelerator, which optimizes the pitch angle of the blade for wind generators in response to the change in wind speed. However, it is prone to many problems, such as excessive repair costs in case of failure. Complex planetary gears are very important parts of a pitch drive system because of strength problem. When gears are designed for the power train of a pitch drive, it is necessary to analyze the fatigue strength of gears. While calculating the specifications of the complex planetary gears along with the bending and compressive stresses of the gears, it is necessary to analyze the fatigue strength of gears to obtain an optimal design of the complex planetary gears in terms of cost and reliability. In this study, the specifications of planetary gears are calculated using a self-developed gear design program. The actual gear bending and compressive stresses of the planetary gear system were analyzed using the Lewes and Hertz equation. Additionally, the calculated specifications of the complex planetary gears were verified by evaluating the results from the Stress - No. of cycles curves of gears.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.688-694
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• 2009

As a drive system for next generation train, we have been making research and development of a direct drive traction motor system without the conventional reduction gear. This traction motor is expected to have many advantages such as low noise, reduced maintenance, and energy saving. Due to the demand for high-output motors in the limited space between the wheels, open-ventilating traction motors with gear box have been widely used for many years. However, a conventional open-ventilating traction motor is necessary periodical disassembly to remove the accumulated dust from open-air ventilation. Reducing this burden, as well as increasing energy efficiency and reducing noise, would benefit the next generation of traction motors. To address these needs, KRRI have been developing a fully enclosed type direct drive motor(DDM) with high-efficiency permanent magnet for the next generation train.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.382-387
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• 2003

This paper proposes the Train Control System for the LRT(light rail transit). With regard to information processing in car, we build a computer network in the car, turned the hardware required for train control into software, and developed the Train Control Monitoring System(TCMS) and ATC. Drive Type of Train control system car can drive with Driverless mode basically, and this paper applied 10Mbps special communication type for car control, data analysis, The propulsion efforts and breaking effort can control the cars. It is used Vector Control in Propulsion control and proposed Operating pattern for Propulsion control thinking Operating data of Rubber Tire LRT.

• Journal of the Korean Society for Railway
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• v.6 no.1
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• pp.49-57
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• 2003

This paper proposes the Train Control System for the LRT(light rail transit). With regard to information processing in car, we build a computer network in the car, turned the hardware required for train control into software, and developed the Train Control Monitoring System(TCMS) and ATC. Drive Type of Train control system car can drive with Driverless mode basically, and this paper applied 10Mbps special communication type for car control, data analysis, The propulsion efforts and breaking effort can control the cars. It is used Vector Control in Propulsion control and proposed Operating pattern for Propulsion control thinking Operating data of Rubber Tire LRT.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.7
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• pp.770-777
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• 2012

This paper deals with the design and modal characteristics analysis of a drive-train for a paralleltype hybrid electric vehicle (HEV). The function of the drive-train system (DTS) in the HEV combines or divides the torque and velocity from the internal combustion engine along with the induction motor. The system consists of a compound planetary gear and unit's electromagnetic clutch to provide the operation modes such as Engine Only (EO), Electric Vehicle (EV), and Hybrid Electric Vehicle (HEV) modes. In order to investigate the characteristics of the velocity and torque flow for the system, dynamic models of the HEV with DTS are derived from the prototype DTS. The performance of the derived dynamic models is evaluated by both computer simulations and experiments according to each mode.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.5
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• pp.344-350
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• 2004

This paper proposes the train control system for the LRT(light rail transit). With regard to information processing in car, we build a computer network in the car, turned the hardware required for train control into software, and developed the train control monitoring system(TCMS) and ATC. Drive type of train control system car can drive with driverless mode basically, and this paper applied special communication type for car control, data analysis, the propulsion efforts and breaking effort can control the cars. It is used vector control in propulsion control and proposed operating pattern for propulsion control thinking operating data of rubber tire LRT.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.223-229
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• 2003

This paper proposes the Train control system for the LRT(light rail transit}. With regard to information processing in car, we build a computer network in the car, turned the hardware required for train control into software, and developed the Train Control Monitoring System and ATC. Drive Type of Train control system car can drive with Driverless mode basically, and this paper applied special communication type for car control, data analysis, The propulsion efforts and breaking effort can control the cars. It is used Vector Control in Propulsion control and proposed Operating pattern for Propulsion control thinking Operating data of Rubber Tire LRT.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.2
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• pp.101-116
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• 2002

Modern vehicles require a high degree of refinement, including good driveability to meet customer demands. Vehicle driveability, which becomes a key decisive factor for marketability, is affected by many parameters such as engine control and the dynamic characteristics in drive lines. Therefore, Engine and drive train characteristics should be considered to achieve a well balanced vehicle response simultaneously. This paper describes analysis procedures using a mathematical model which has been developed to simulate spark timing control logic. Inertia mass moment, stiffness and damping coefficient of engine and drive train were simulated to analyze the effect of parameters which were related vehicle dynamic behavior. Inertia mass moment of engine and stiffness of drive line were shown key factors for the shuffle characteristics. It was found that torque increase rate, torque reduction rate and torque recovery timing and rate influenced the shuffle characteristics at the tip-in condition for the given system in this study.