• Tribology and Lubricants
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• v.29 no.2
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• pp.111-116
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• 2013

This paper describes the adherence phenomenon, including the tribological characteristics, of a low-pressure fuel pump in a diesel engine for an excavator. Most fuel pumps of a diesel-engine excavator are of the fixed-quantity-gear type and have low pressure. However, the developed pumps develop problems in the pumping system owing to performance instability. Cavitation, which is the main obstacle to stable driving in the pump, occurs between an idle gear and the housing to produce a serious adherence problem. The present study not only examined how to suppress cavitation in a pump but also developed a simple method to improve pump performance through the early creation of a lubrication film with a phosphoric acid coating on the surface of the idle gear. The results showed that the coating successfully prevents breakage of the idle gear due to adherence.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.933-934
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• 2012

• Journal of Aerospace System Engineering
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• v.14 no.1
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• pp.1-7
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• 2020

This paper discusses a series of procedures and results for designing the gear part of a fuel transfer pump for an aircraft, developed as an independent technology for the first time in Korea. A gear pump type is selected because the design requirements of the fuel transfer pump are met by a gear pump with a characteristics of less leakage inside than a vane pump with superior overall performance. The gear housing is designed with suitable clearance, considering the outer diameter of the gear, which is the main factor on which the flow can be determined. Additionally, the calculation of the required hydraulic and axial force for the motor to drive the fuel transfer pump was performed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.14-20
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• 2012

Performance and anti-corrosion of cold forged fuel pumps and die-casting fuel pumps have been tested in this study. Ethanol with 10 ppm of acetic acid is applied for the anti-corrosion test for 250 hours. Performance test result shows that the pumping efficiency of the cold forged fuel pump is equivalent to that of the die-casting fuel pump. The cold forged lower housing has better quality against corrosiveness and finer metallic structure than the die-casting lower housing does.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.5
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• pp.97-102
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• 2018

Combat vehicles require high levels of maneuverability, firepower, armor, and operability. A high-performance power system is required for optimal maneuverability. The fuel pump which supplies fuel stably is very important to achieve this. The fuel pump consists of a pump part, a motor part, and a control part. It is equipped with a BLDC motor. Numerous failures of the fuel pump occurred during vehicle operation when exposed to vibration, shock, and high temperature. The cause of failure was confirmed to be stator slip of the BLDC motor. Stator slip is a consequence of the interference loss between the stator and the housing of the motor part in an high temperature environment. The failure of the fuel pump was solved through size control of the motor housing and the stator. We performed vibration testing at high temperature for verification. This study contributes to improving the reliability of combat vehicles.

• Journal of Aerospace System Engineering
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• v.17 no.5
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• pp.11-18
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• 2023

The architecture of the Fuel Thermal Management System (FTMS) in a commercial aircraft engine was built to model and simulate the fuel system. The study shows the thermal interactions between the fuel and engine lubrication oil through the mission profile of a high bypass ratio, two-spool turbofan engine. Fuel temperature was monitored as it flowed through each sub-component of the fuel system during the mission. The heat load in the fuel system strongly depended on the fuel flow rate, and was significantly increased for the periods of cruise and descent with decrease of fuel flow rate, rather than for the periods of take-off. Due to the thermal interaction in the pump housing, the fuel temperature at the outlet of the low-pressure pump was increased (4.0, 9.2, and 30.0) % over the case without thermal interaction for take-off, cruise, and descent, respectively.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.47-53
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• 2015

This paper is to study applying for numerical analysis method for flow field, velocity and pressure of fuel on the low pressure pump using excavator. The pressure distribution of fuel pump certified the linear variation according to rotation angle of rotor. Especially, it knew the fact that the pressure in rotation angle $40^{\circ}$ appeared high outlet and low inlet of fuel pump. Also, this range angle can seek the fact that the leakage flow and velocity are the most increasing. And the more rotor rotation of fuel pump, the more mean outlet flow rate increased in linear. Whenever the gap size decrease with rotor and housing, the discharge flow rate could seek the approaching 0.0712kg/s that consider with theory discharge flow rate calculated from displacement between rotor gear and idle gear.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.634-640
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• 2020

Failure analysis and heat-resistant were performed for an electric fuel pump that is installed in the fuel tank to transfer fuel to the engine of combat vehicles. The fuel pump with a DC motor was disassembled and inspected to determine the cause of failure. The failure phenomenon was classified into three categories based on observations of the inside of the housing: burnt winding, quick brush abrasion, and fuel leak into the pump. Based on the inspection results, it was estimated that overheating was the main cause of failure. The thermal test was conducted under the no-load condition in 24 hours, and the thermal sensor was installed on the stator surface and the brush holder to check the possibility of damage to the winding due to overheating. When the ambient temperature of the fuel pump was set to 68 ℃, the stator temperature increased to 135.9 ℃, and the winding of the motor was almost damaged. The test results confirmed the lack of heat resistance of fuel pump windings, and suggested that the type F of insulation class (below 155 ℃) of the windings and varnish should be replaced with type C or higher that can be used above 180 ℃.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.8 no.4
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• pp.17-23
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• 2012

Due to reinforcement of international environment regulation and high oil prices, interest in renewable energy is growing. Countries participating in UNFCCC are continuously putting efforts in reducing greenhouse gas after enforcing Kyoto Protocol into effect on Feb, 2005. Energy used in buildings, which relies heavily on fossil fuel accounts for about 24% of total energy consumption. In this study, air, geothermal and water source heat pump systems for an 322 $m^2$ auditorium in an office building is simulated using TRNSYS version 17 for comparing energy consumptions. The results show that energy consumptions of air, geothermal and water source heat pumps are 14,485, 10,249, and 10,405 kWh, respectively. Annual equal payments which consider both initial and running costs become 5,734,521, 6,403,257 and 5,596,058 Won. Thus, water source heat pump is the best economical choice.

• Proceedings of the KAIS Fall Conference
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• 2011.12b
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• pp.521-524
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• 2011

본 논문에서는 냉간단조된 연료펌프와 다이캐스팅된 연료펌프에 대한 성능 실험을 수행하였다. 수행결과 냉간단조와 다이캐스팅으로 가공된 하부하우징으로 제작된 연료펌프는 회전수마다 미미한 차이를 보이지만, 전체적으로 동등한 성능을 보이고 있다.