• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.250-250
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• 2004

자동차의 시동을 걸기 위해서는 맨 처음 엔진을 강제로 가동시키는 기계장치가 있어야 하며, 이를 시동모터라 한다. 시동모터는 모터부와 그 부속장치 그리고 발생된 힘을 엔진으로 전달하는 동력전달 기구로 구성되어 있다. 동력전달기구는 플라이 휠이라는 부품을 크랭크 축 끝단에 장착한 후 그 원주상에 링 기어를 만들고, 시동모터의 축에 피니언이라는 작은 기어를 맞물리게 하여 시동 키를 돌리면 이 기어가 회전되는 원리를 이용하고 있다. 피니언 기어는 작고 반대로 플라이 휠에 장착되어 있는 링 기어는 크기 때문에 일정한 기어비가 형성되어 큰 부하의 엔진회전이 가능하다.(중략)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.774-780
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• 2021

The auxiliary power unit (APU) of a rotorcraft starts the engine during operation/flying. The APU is composed of a gas turbine engine type. The starting principle of the component is that the electric start motor generates the power required for starting by rotating the shaft. In this study, quality improvement was performed by applying an over-running clutch (ORC) between the APU and the starter motor to secure the operability of the starter motor of the APU mounted on the rotorcraft. The starter motor has the main role of starting the APU, but during operation, it is rotated without load by the rotational force of the APU gear shaft, resulting in friction at the brush. This phenomenon causes abrasion of the brush of the starter motor. Consequently, when the APU operation time increases, the brush life decreases, and the operability of the APU is affected. In this study, an ORC that separates the interlocking between the start motor brush abrasion and the APU operation time was applied to improve the operability/durability of the APU starter motor. The effect was verified through a test, and the technical feasibility of the design change was analyzed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.379-382
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• 2011

Engine test as well as unload test of starting motor itself was performed to evaluate the braking characteristics of starting system used for initial spin-up of gas turbine for power generation. Through the experimental evaluation of the braking performance with the capacity of braking resistor of the starting motor, we have achieved quantitative data to secure robust braking characteristics in emergency during the starting period of the gas turbine. It is possible to establish a capacity selection criterion of braking resistor to ensure the starting reliability of the gas turbine.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.1
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• pp.93-100
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• 2017

Four-stroke cycles in an automobile engine are suction stroke, compression stroke, combustion stroke and exhaustion stroke. A normal operation of engine in compression and power stroke must be processed in optimal fuel-air pressure. In this paper we describe a development of measuring equipment for engine cylinder pressure with observing supply current to self motor(start motor). By comparing the current wave on pressure of the 4 or 6 cylinder in engine, a abnormal cylinder state will be found. The validity of the proposed measuring equipment was shown by experiment for real automobile.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.829-832
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• 2010

For gas turbine engine starting, external power should be supplied with engine to accelerate to suitable rotational speed for air and fuel ignition conditions. Electric starting system for small gas turbine engine has simple system and light weight, so it is generally used for small aircraft. For system analysis of gas turbine engine electric starting system, Characteristics of battery, start motor, engine drag torque should be analyzed and theirs temperature effects should be considered. In this paper, preliminary design procedure of small gas turbine engine electric starting system and major design parameters were described.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1111-1112
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• 2010

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.4
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• pp.16-23
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• 2008

Theoretical and numerical approaches were conducted in order to study supersonic exhaust diffusers to simulate high altitude performance of rockets on the ground. A physical model of concern includes a rocket motor, vacuum chamber, and diffuser, which have axisymmetric configurations. An analysis was conducted to investigate operation characteristics of supersonic exhaust diffusers from a flow-development point of view. Emphasis was placed on theoretical formulation to predict the starting pressure of diffusers, the effect of the vacuum chamber size, and the minimum starting pressure of the rocket motor to start the diffuser.

• Tribology and Lubricants
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• v.26 no.5
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• pp.277-282
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• 2010

The purpose of this paper is to study and analysis the failure examples for parasitic current leakage produced in starting system on gasoline engine. It verified the discharge of battery by electric leakage because of internal wiring damage problem for CD auto changer installed in car. Also, it verified the no-stating phenomenon because of deposit forming by chemical reaction of battery fluid between battery post and cable fixing parts. It verified the damage for brush holder and commutator mixing by internal short phenomenon because of brush carbon a particle and engine oil that was flowed into internal of starting motor. It verified the working phenomenon of audio by a point of contact even if the driver turn to "LOCK" position the key.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.1
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• pp.32-39
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• 2000

To optimize the cold start process of a 4-stroke, 8 cylinder Diesel engine, a dynamic simulation model from cranking to idle speed is developed. Physically-based first order starter motor dynamics are used to model the performance of starting process which is very complex. These equations are solved using numerical schemes(Petzold-Gear BDF method) to describe the starting process of diesel engine and to study the effects of starting parameters. The validity of this model is examined by start test. This model can be served as a tool for computer aided control systems design to improve cold improve cold start performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.703-709
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• 2017

Korea Utility Helicopter(KUH) is a project to replace the aging helicopter presently being operated by the military with a domestic helicopter. The auxiliary power unit is a device that supplies emergency power to the system by an alternator installed when the main generator fails and the start motor converts the electrical energy of the battery into mechanical rotational energy to rotate the auxiliary power unit engine. With continuing power and operation, defects of the starting motor were found and improvements were carried out to solve it. In the failure mode analysis, the causes of possible defects were classified into 5 categories. Analysis of the 5 factors revealed that the main cause of defects is mechanical wear, which was found to be related to spring pressure. 250 tests were conducted through the theoretically determined pressure and regression analysis was performed with 4 sampling.The results showed that pressure was related to wear rate. In conclusion, early wear and breakage due to wear can be controlled through spring force and test showed the prediction of wear and the validity of the result were confirmed.