• Transactions of The Korea Fluid Power Systems Society
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• 제4권3호
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• pp.7-12
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• 2007

This paper presents an energy saving hydrostatic pressure exchanger for sea water desalination equipment. In a reverse osmosis(RO) system for desalinating sea water, more than 70 percent of the supplied sea water, brines which were impassable through RO membrane are bypassed, resulting in high energy losses. In this paper, a hydrostatic pressure exchanger consisting of an embedded water hydraulic piston motor and a water hydraulic piston pump was proposed and investigated in order to recover the energy of the bypassed brines. The pressurized brines are supplied to the embedded water hydraulic piston motor as power sources and the water hydraulic piston pump is driven by the output torque of the embedded water hydraulic piston motor as well as electric motor. Consequently, the energy of the bypassed brines can be recovered. To examine the electric energy saving characteristics of the hydrostatic pressure exchanger, a simulation model was constructed using commercial software and experiments were conducted. Through the results of simulation and experiment, the feasibility of the electric energy saving effect of the proposed hydrostatic pressure exchanger was investigated.

• Journal of the Korean Society of Manufacturing Process Engineers
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• 제18권9호
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• pp.64-71
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• 2019

We herein propose a systematic design method of hydraulic pipes used in heavy construction equipment. We found that even though many design studies have been conducted regarding major hydraulic components such as pumps, cylinders, and control valves, studies regarding the optimal design of hydraulic pipes are scarce. In this study, the design of four types of pipes is considered: two high-pressure and two low-pressure pipes. First, fluid flow analysis was conducted based on oil flow and pressure for various radii of curvature. For a check-valve pipe, we considered the location of an inlet pipe. We could visualize fluid flow inside the pipe according to the flow velocity and pressure distribution. Based on fluid flow analysis, we conducted a structural analysis that revealed the stress distribution and concentration for each pipe design. We selected the best design parameters for each pipe design, fabricated the pipes, and subsequently tested them for validity.

• Journal of Drive and Control
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• 제2권2호
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• pp.8-12
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• 2005

• Journal of Drive and Control
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• 제10권1호
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• pp.72-74
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• 2013

• Journal of Drive and Control
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• 제9권1호
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• pp.52-55
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• 2012

• Journal of Drive and Control
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• 제15권4호
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• pp.139-147
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• 2018

• Transactions of The Korea Fluid Power Systems Society
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• 제3권3호
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• pp.8-13
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• 2006

It is very important for the manufacturers to predict the life of hydraulic system components according to the results of life tests. Since it takes too much time to test the hydraulic system components until failure, the no-failure test method is applied for the life test of them. If the shape parameter of Weibull distribution, the number of samples, the confidence level, and the assurance life are given, the no-failure test times of hydraulic system components can be calculated by given equation. Here, the procedures to obtain the no-failure test times of the hydraulic system components such as hydraulic motors and pumps, hydraulic cylinders, hydraulic valves, hydraulic accumulators, hydraulic hoses, and hydraulic filters are described briefly.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.608-613
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• 1997

This study discusses the developmentof hydraulic rotary actuator design technology for industriol machinery and earthmoving equipment. The lubrication and wear analysis of sliding components of the machinery are very important parameters to sterngth the design technique. The analysis and were test are performed for the selected materials of the above mentioned coupled sliding members using the experimental results. One can selsct the better combination of sliding components.

• Tribology and Lubricants
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• 제19권1호
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• pp.36-42
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• 2003

Nowadays the importance of equipment reliability and efficiency is increasing and the concept of Total Fluid Management is introduced to make production cost down and improve equipment reliability. In this paper, basic survey on the current status of lubricants application and equipment maintenance is made. Lubrication point of the factory was 233 and 60 percent of the point was lubricated by hydraulic oils. Lubricants used at 87 points were different from those of original equipment manufacturers' recommendation. And 40 percent of the points are heavily contaminated. Exchange of oils, use of filter, computerization and so on were recommended. And introduction of Total Fluid Management concept is required.

• Journal of the Korean Society of Industry Convergence
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• 제4권3호
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• pp.305-310
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• 2001

Hydraulic power shifting systems of hydraulic travel motor may be far safer than mechanical power transmission systems. Thus, hydraulic power shifting systems are widely used for speed control on the hydraulic equipments. In the case of liquid shifting lines, the rapid change of area, such as valve closing, can result in a large pressure transient. It is necessary to assure proper control method in order to obtain the smallest shift shock. This study conducts the shock characteristics of hydraulic power shifting system of the hydraulic travel motor. Experimental results show that shock pressure depends on the operating pressure, flow rate and pipe line area. The shock characteristics can be applied for reducing shocks.