• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.4738-4744
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• 2011

This study proposes the system of new small sluice gate operated without the upper concrete structure. The new mechanism is composed of hydraulic system, driving mechanism to feed the floodgate up and down, hydrological locking device, safety device and etc. The hydraulic pumps and control systems away from the location of the sluice gate systems are installed and controled in place. The feed device with the hydraulic rack, pinion and hydraulic actuator is installed on the side of the sluice gate. The following results take the advantages of cost reduction, operation safety and compact product.

• Journal of Drive and Control
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• v.18 no.2
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• pp.1-8
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• 2021

In this work, a circuit with a hydraulic power unit is formulated as a means of predicting the behavior of the prefill valve in the future. The behavior of the prefill valve can be examined by the measurements of the configured power unit, and the performance is determined by using hydraulic pumps, relief valves, and hydraulic hoses that make up the power unit. In particular, pressure/flow pulsation generated by hydraulic pumps can cause instability in the prefill valve and cause noise-induced degradation of the overall performance and reliability of the hydraulic system containing the prefill valve. Therefore, to study the behavior and performance of the prefill valve in a relatively accurate manner, the prediction of the characteristics of the hydraulic power unit driving the prefill valve is very important. In this study, the pulsation characteristics of the hydraulic pump were analyzed to theoretically demonstrate its relationship with different settings of the power unit, such as relief valve pressure settings and the presence/absence of the hose.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.2
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• pp.197-204
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• 2004

An accumulator in hydraulic systems stores kinetic energy during braking action, and then that controls hasty surge pressure. An energy recovery system using accumulator seems to be advantageous for ERBS due to its high energy density. This study suggests a method to decide suitable accumulator volume for ERBS. The method is based upon energy conservation between kinetic energy of moving inertia and elastic energy of accumulator. The energy conversion was analyzed and a simple formula was derived. Also accumulator tests were conducted for different load mass and motor speed. A series of test work were carried out in the laboratory and the dynamic characteristics of the hydraulic motor system, such as the surge pressure and response time, were investigated in both brake action and acceleration action and these results show that the proposed design is effective for decision accumulator volume in ERBS.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.157-160
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• 2004

In this paper, a performance characteristic pump and motor is investigated. The hydraulic pump and motor are axial piston type with swash plate. Proportional control valve which can control that plate is an important component for its performance characteristics. We will show the control characteristics for them Experiment results show that behavior can be shown with changing the various parameters.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.06a
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• pp.62-67
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• 2000

This paper was undertaken to do morphological analysis of wear debris for slipper-Pad of hydraulic rotary acuator. The lubricating wear test was performed under different experimental conditions using the wear test device and wear specimens of the pin on disk type was rubbed in paraffinic base oil by three kinds of lubricating materials, varying applied load, sliding distance. The four shape parameters(50% volumetric diameter, aspect, roundness and reflectivity) are used for morphological analysis of wear debris. The results showed that the four shape parameters of wear debris depend on a kind of the lubricating condition. It was capable of presuming wear volume for slipper-pad of hydraulic rotary acuator on driving time.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.257-258
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• 2002

The surface morphology of oil-lubricated surface for hydraulic piston motor is believed to be extremely effective in contact mechanics. adhesion. friction and wear. In order to describe morphology of various rubbed surface on driving condition, the wear test was carried out under different experimental conditions in oil-lubricated system. And fractal descriptors was applied to rubbed surface of hydraulic members with image processing system. These descriptors to analyze surface structure are fractal dimension. Surface fractal dimension can be determined by sum of intensity difference of surface pixel. Morphology of rubbed surface can be effectively obtained by fractal dimension.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.307-311
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• 2004

In this study, a novel hybrid vehicle is proposed. The vehicle has a flywheel-engine hybrid system. Flywheels are more effective as energy charge systems than electric batteries in a respect of output power density. However, transmissions to effectively drive flywheels are very complex systems such as CVTs (Continuously Variable Transmissions). In the proposed hybrid vehicle, Constant Pressure System is employed, which is hydraulic power transmission. Using Constant Pressure Systems, hydraulic CVTs are easily realized with variable displacement pumps/motors. In this paper, firstly, the proposed flywheel hybrid vehicle making use of Constant Pressure System is described. Secondly, fuel consumption characteristics of the flywheel hybrid vehicle are experimentally examined with the stationary test facility, which employs a flywheel as a load emulating vehicle inertia. Finally, the experimental results and discussions are described. Fuel consumption of 26km/L is expected for 10 mode driving schedule with vehicle mass of 1500kg.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.3
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• pp.654-662
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• 1998

Shift quality of an automatic transmission in a vehicle is mainly affected by transient pressures in the hydraulic system during shifting. In this study, dynamic modelings of the hydraulic system and the power train of an automatic transmission are made systematically by a bond-graph method. The dynamic characteristics of the line pressures and clutch/brake pressures during shiftings are investigated by simulations and verified by experiments. The effects of clutch/brake pressures on the shift torque are also investigated through driving simulation.

• KSTLE International Journal
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• v.3 no.2
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• pp.75-78
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• 2002

The surface morphology of oil-lubricated surfaces fer hydraulic piston motors is believed to be extremely effective in contact mechanics, adhesion, friction and weak In order to describe morphology of various rubbed surfaces on driving conditions, the wear test was carried out under different experimental conditions in an oil-lubricated system. And fractal descriptors were applied to rubbed surfaces of hydraulic members and analyzed through an image processing system. These descriptors to analyze surface structure are fractal dimension. Surface fractal dimensions can be determined by sum of intensity difference of surface pixel. The morphology of rubbed surfaces can be effectively obtained by fractal dimension.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.1
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• pp.84-91
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• 2003

The equipment of textiles let off is a part of inspection machine which inspects finished textiles and it checks up textiles through that. This study suggests a method to select the capacity and initial gas pressure of accumulator to control surge rising pressure occurring when suddenly braking action to a desired degree. An accumulator in hydraulic systems is by hydraulic machinery which stores kinetic energy of inertia body during braking. A series of computer simulations were done for the brake action The results of the simulation work were compared with those of experiments.