상용차용 전동식 클러치의 동적특성에 관한 연구

조인성(Ihnsung Cho),정재연(Jaeyoun Jung) 한국자동차공학회 2014 한국 자동차공학회논문집 Vol.22 No.1

왕복동식 압축기 피스톤의 역학적 거동특성

조인성(Ihnsung Cho) 한국트라이볼로지학회 2013 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.29 No.2

Refrigeration and air-conditioning compressors used in home appliances, including refrigerators and air conditioners, are typically hermetic-type reciprocating compressors. Because the shell is sealed by welding, it should be designed to have a semi-permanent life. The energy consumption of a hermetic-type reciprocating compressor is low, but because it operates continuously to maintain a constant temperature inside the refrigerator, it has a certain base load. In this type of compressor, the driving motor operates at a high speed (about 3,000 - 3,600 rpm), which causes valve damage, friction, wear, and high-frequency noise. Many studies have been conducted to solve these problems. To enhance the reliability and efficiency of the reciprocating compressor, the design conditions and operating environment of journal bearings should be considered. Dynamic behavior analysis should be carried out in terms of the discharge pressure. The results showed that the load (discharge pressure) increases in the forward lookup zone and decreases in the backward lookup zone. When the revolution speed is increased, the maximum load decreases in the region where the maximum load operates.

냉동 공조용 로터리 콤프레서의 베인과 롤링 피스톤간의 마찰 특성

조인성(IhnSung Cho),송규근(KyuKeun Song),정재연(Jae Youn Jung),오석형(SeokHyung Oh) 한국트라이볼로지학회 2005 한국트라이볼로지학회 학술대회 Vol.2005 No.6

The rolling piston type-rotary compressor has been widely used for refrigeration and air-conditioning systems due to its compactness and high-speed operation. The present analysis is part of a research program directed toward maximizing the advantages of refrigerant compressors. The study of lubrication characteristics in the critical sliding component is essential for the design of refrigerant compressors. Therefore, experimental investigation of the lubrication characteristics of a rotary compressor used for refrigeration and air-conditioning systems was studied. In order to measure the friction force between the vane and rolling piston, an experimental apparatus known as the Pin-on-Disk was used. Load is applied by the hydraulic servo valve controlling the pressure of the hydraulic cylinder. The results showed that the rotational speed of a shaft and the discharge pressure significantly influence the friction force between the vane and the rolling piston.

자동차용 유압베인펌프의 고속에서 베인과 캠링간의 이간현상

조인성(IhnSung Cho),백일현(IlHyun Baek),정재연(JaeYoun Jung) 한국트라이볼로지학회 2010 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.26 No.2

In an oil hydraulic vane pump for an automobile, it is very important that the vane doesn’t separate from the camring inner race during the operation of the vane pump. The vane generally has not only the oil hydraulic force acting on the bottom face to contact to camring inner race but there is also an inertial force and viscous force. Because the oil hydraulic force is much larger than the other forces, the contact state between the vane tip and the camring inner race is sufficient. However, the contact state between the vane tip and the camring inner race is only affected by the inertial and viscous forces during the delivery of the vane pump, because the oil hydraulic force acting on the vane is in equilibrium. If the inertial force is larger than the viscous force, which happens when the vane is separated from the camring inner race, the delivery of the vane pump can become unstable or the volume efficiency can become decrease rapidly. Therefore, in this paper, the state of the contact between the vane and the camring is considered. The results show that the rotating speed of the shaft, the operating temperature of the oil, the clearance between the vane and the rotor, and the mass of the vane exert a great influence on the state of the contact between the vane and the camring.

유성 기어 유동 중개륜의 컴플라이언스 해석

조인성(Ihnsung Cho) 한국트라이볼로지학회 2013 한국윤활학회지(윤활학회지) Vol.29 No.6

An epicyclic gearing system is compact and lightweight. However, it is difficult to share the driving force equally because the system has closed gear trains with multiple driving points, and it always has geometrical errors in the elements. Thus, in the case of planetary gears, the first problem is how to distribute the load evenly to the numerous planets. The method widely used abroad for this purpose is to utilize the elastic deformation of the components of the structure. However, the deflection is very complicated, and it is very easy for vibration problems to occur because of the decrease in the natural frequencies. Therefore, to equalize the load on the planets, this paper discusses the principle and theory behind the functioning of a floating intermediate ring. This magnifies the displacement of a planet"s center arising from the equilibrium of the load and the lubricating film pressure, which improves the compliance of the planets . The results show that load equalization of the planets is possible through this improvement in their compliance.

사판식 유압 피스톤 펌프의 슬리퍼와 사판 간의 윤활 특성

조인성(Ihnsung Cho) 한국트라이볼로지학회 2013 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.29 No.3

Hydraulic systems are used to transform mechanical energy into fluid energy and vice versa. They are widely applied in various industries; e.g., they are used in automobiles, public works, rockets, machine tools, heavy construction equipment, and airplanes. Hydraulic pumps are used to transform the energy in these systems. In this study, with the basic operation principles as a starting point, I attempted to clarify how the shape of a slipper affects the lubrication characteristics under practical conditions. A swashplate with a tilt angle of zero and capable of rotating motion was used, along with other devices. A slipper was located at 45 mm eccentricity from the center of the swashplate. The results of this experiment indicated that the shape of the bottom surface of a slipper affects the load capacity, leakage flow, and lubrication characteristics and that the slipper is one of the most important parts for improving the pump efficiency.

사축식 피스톤 펌프에서 2중 피스톤 링의 윤활 특성

정재연(JaeYoun Jung),조인성(IhnSung Cho),백일현(IlHyun Beak),조재천(JaeCheon Jo),송규근(KyuKeun Song),오석형(SeokHyung Oh) 한국트라이볼로지학회 2009 한국트라이볼로지학회 학술대회 Vol.2009 No.6

The bent-axis type piston pump which is driven by the piston rod works on the way that the piston rod drives the cylinder block, so the taper angle of the piston rod and the swivel angle between the cylinder block and the shaft are very Important design factors. If the above factors can not satisfy the conditions of optimum design, the friction loss between the cylinder bore and the piston increases, and the pump can even fail to work under conditions of severe friction and wear. Since the piston reciprocates in the cylinder bore with high velocity, and at the same time it rotates on its own axis and revolves on the center of the cylinder block, the decrease of the volume efficiency generated on account of the leakage between the cylinder bore and the piston. Therefore, to prevent this case, the piston ring is designed at the end of the piston, and the friction characteristics between the piston ring and the cylinder bore are in need of research due to its great influence on the performance of piston pump. Thus, in this paper, the elastohydrodynamic lubrication(EHL) analysis of the film thickness, the pressure distribution and the friction force, have been studied between the piston ring and the cylinder bore in the bent-axis type piston pump. The analyzed results show that friction force is influenced by rotating speed and discharge pressure.

차량용 사축식 피스톤 펌프의 피스톤 링과 실린더 보어간의 윤활특성에 관한 연구

정재연(JaeYoun Jung),조인성(IhnSung Cho),송규근(KyuKeun Song),백일현(IIHyun Baek),오석형(SeokHyung Oh),정석훈(SeokHoon Jung),정용욱(YongWook Jeong) 한국트라이볼로지학회 2007 한국윤활학회지(윤활학회지) Vol.23 No.5

The bent-axis type piston pump which is driven by the piston rod works on the way that the piston rod drives the cylinder block, so the taper angle of the piston rod and the swivel angle between the cylinder block and the shaft are very important design factors. If the above factors cannot satisfy the conditions of optimum design, the friction loss between the cylinder bore and the piston increases, and the pump can even fail to work under conditions of severe friction and wear. Since the piston reciprocates in the cylinder bore with high velocity, and at the same time it rotates on its own axis and revolves on the center of the cylinder block, the decrease of the volume efficiency generated on account of the leakage between the cylinder bore and the piston. Therefore, to prevent this case, the piston ring is designed at the end of the piston, and the friction characteristics between the piston ring and the cylinder bore are in need of research due to its great influence on the performance of piston pump. Thus, in this paper, the elastic hydraulic oil's lubrication analyses of the film thickness, the pressure distribution, and the friction force, and so on, have been performed, and the lubrication characteristics between the piston ring and the cylinder bore are explored by the results of the numerical analysis, and it is contributed to realize the higher efficiency and the more advanced performance of the bent-axis type piston pump.

사축식 피스톤 펌프의 피스톤 링과 실린더 블록 사이의 윤활 해석

정재연(JaeYoun Jung),조인성(IhnSung Cho),백일현(IlHyun Beak),신현일(HyunIl Shin),송규근(KyuKeun Song),오석형(SeokHyung Oh),장동혁(DongHyuk Jang) 한국트라이볼로지학회 2008 한국트라이볼로지학회 학술대회 Vol.2008 No.11

The bent-axis type piston pump which is driven by the piston rod works on the way that the piston rod drives the cylinder block, so the taper angle of the piston rod and the swivel angle between the cylinder block and the shaft are very important design factors. If the above factors can not satisfy the conditions of optimum design, the friction loss between the cylinder bore and the piston increases, and the pump can even fail to work under conditions of severe friction and wear. Since the piston reciprocates in the cylinder bore with high velocity, and at the same time it rotates on its own axis and revolves on the center of the cylinder block, the decrease of the volume efficiency generated on account of the leakage between the cylinder bore and the piston. Therefore, to prevent this case, the piston ring is designed at the end of the piston, and the friction characteristics between the piston ring and the cylinder bore are in need of research due to its great influence on the performance of piston pump. Thus, in this paper, the elastohydrodynamic lubrication(EHL) analysis of the film thickness, the pressure distribution and the friction force, have been studied between the piston ring and the cylinder bore in the bent-axis type piston pump. The analyzed results show that friction force is influenced by rotating speed and discharge pressure.

자동차용 유압 베인 펌프의 기동 시 베인과 캠링의 이간

정재연(JaeYoun Jung),조인성(IhnSung Cho),백일현(IlHyun Beak),조재천(JaeCheon Jo),송규근(KyuKeun Song),오석형(SeokHyung Oh) 한국트라이볼로지학회 2009 한국트라이볼로지학회 학술대회 Vol.2009 No.11

In an oil hydraulic vane pump for automobile, it is very important that the vane doesn't have to be separated from the camring inner race in operation of the vane pump. Generally, the vane has not only the oil hydraulic force acting on the bottom face to contact camring inner race but also inertial force and viscous force. Because the oil hydraulic force is much larger than the other forces, the contact state between the vane tip and the camring inner race is good. However, in the starting of the vane pump, because the oil hydraulic force acting on the vane is zero, the contact state between the vane tip and the camring inner race is affected with only the other forces. If the viscous force larger than the inertial force, because the vane is separated from the camring inner race, the suction and delivery of the vane pump can be unstable or impossible. Therefore, in this paper, the state of the contact between the vane and the camring is considered. The results show that the rotating speed of the shaft, the operating temperature of the oil, the clearance between the vane and the rotor and the mass of the vane exert a great influence on the state of the contact between the vane and the camring.