• 대한기계학회논문집A
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• 제38권3호
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• pp.295-302
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• 2014

내접형 기어펌프의 경우 내구성과 소형화의 장점을 가지고 있으나, 유량증대 및 소음저감의 성능개선이 요구되고 있다. 본 논문에서는 외부로브 형상이 다양한 곡선 조합(타원 1-인볼루트-타원 2)인 경우에 대하여 기구학적 치형 형상 관계식을 유도하고, 창성된 치형에 대해 소음에 관계된 성능인자(압력각, 유량맥동과 미끄럼률)를 예측하여 소음정도를 수치적으로 비교하였다. 또한 이론 해석을 통해 구한 치형형상과 성능인자 예측 알고리즘을 통하여 설계변수와 성능인자간의 영향도를 분석하였고, 분석 결과를 바탕으로 일정한 유량성능을 유지하면서 소음이 저감된 치형의 최적설계를 수행하였다. 해석결과를 바탕으로 제시된 치형의 최적설계에 대한 시제품 제작 및 소음 시험을 통해 설계의 타당성을 검증하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1997년도 추계학술대회논문집; 한국과학기술회관; 6 Nov. 1997
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• pp.132-137
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• 1997

In this study, the effect of load torque on the synchronous whirling of a rotor system has been studied analytically. Results show that the critical value of load torque to damping exists above which synchronous response decreases with increasing load torque. It has been also shown that the synchronous whirling amplitudes are more sensitive to the value of eccentricity and the ratio of disk radius to shaft length of the rotor system than other design parameters for a fixed value of load torque.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.214-214
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• 2008

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 춘계학술대회 논문집
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• pp.100-101
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• 2010

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.400-401
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• 2012

• 한국소음진동공학회논문집
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• 제17권12호
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• pp.1208-1216
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• 2007

Turbomachinery such as turbines, pumps and compressors, which are installed in transportation systems, including aircrafts, ships, and space vehicles, etc., often perform crucial missions and are exposed to potential dangerous impact environments such as base-transferred shock forces. To protect turbomachinery from excessive shock forces, it may be needed to accurately analyze transient responses of their rotors, considering the dynamics of mount designs to be applied. In this study a generalized FE transient response analysis model, introducing relative displacements, is proposed to accurately predict transient responses of a flexible rotor-bearing system with mount systems to base-transferred shock forces. In the transient analyses the state-space Newmark method of a direct time integration scheme is utilized, which is based on the average velocity concept. Results show that for the identical mount systems considered, the proposed FE-based detailed flexible rotor model yields more reduced transient vibration responses to the same shocks than a conventional simple model, obtained by treating a rotor as concentrated lumped mass, equivalent spring and a damper or Jeffcott rotor model. Hence, in order to design a rotor-bearing system with a more compact light-weighted mount system, preparing against any potential excessive shock, the proposed FE transient response analysis model herein is recommended.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.242-247
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• 2004

In this study was proposed a transient response analysis technique of a rotor system, applying the generalized FE modeling method of a rotor-bearing system considering a base-transferred shock force and together the state-space Newmark method of direct time integration scheme based on the average velocity concept. Experiments were performed to a test rig of a mock-up rotor-bearing system with series of half-sine shock waves imposed by an electromagnetic shaker, and quantitative error analyses between analytical and experimental results were carried out. The transient reponses of the rotor were sensitive to duration times and shape-qualities of the shock waves, and overally the analytical results agreed quite well with the experimental ones. Particularly, in cases that the frequencies, $1/(2{\times}duration\;time)$, of the shock waves were close to the critical speed of the rotor-bearing system, resonances occurred and the transient responses of the rotor were amplified.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.121-127
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• 2012

Whine noise in engine oil pump system was issued in developing an engine. Generally, A noise of engine oil pump largely are classified two cases. The first one is a gearing noise caused by relative motion of inner rotor and outer rotor. The other is fluid pulsation noise caused by oil pressure fluctuation. The aim of the paper is to identify a noise mechanism in engine oil pump and improve its Noise. Also, it suggests to the guide line on the design of oil pump.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.188-190
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• 2006

This paper describes the effects of air gap eccentricity in induction machines. Asymmetric electro-magnetic force caused by the frictional worn bearing, rotor misalignment and unbalanced rotor etc. generates an asymmetrical operation, vibration and electro-magnetic noise. The need for detection of these rotor eccentricities has pushed the development of monitoring methods with increasing sensitivity and noise immunity. In this paper, we focus on investigating the asymmetrical operation considering of unbalanced magnetic force in squirrel-cage induction motor with 380 [V], 7.5 [kW], 4P, 1,768 [rpm]. The effects of the rotor eccentricity, magnetic force are investigated by finite element method (FEM).

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.301-307
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• 2005

In this study, simplified whirl flutter analyses using quasisteady aerodynamic theory have been performed for a 2-DOF tilt-rotor system with both pitch and yaw motions of a rotor-nacelle. The present dynamic system consists of the rotor (propeller), forming the gyroscopic and aerodynamic element, supported horizontally by a pylon that is pivoted at some wing attachment point. Several design parameters (or rotor-nacelle system are considered and the effect of whirl flutter stability are also investigated for various design parameters.