• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.30 no.6 s.249
• /
• pp.662-669
• /
• 2006

The pneumatic muscle actuator consists of an air bellows tube with two end-flanges. The air bellows tube is made from rubber layers and flexible sheathing formed from nylon 6 fibers. This structure can be stretched or compressed to convert the radial expansive forces into contractile forces. We performed the finite element analysis and the performance test of pneumatic muscle actuator. Also, the pneumatic muscle actuator was manufactured and tested by home-made tester. The results of FEA was similar with performance test below the maximum error of 42 %.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2014.11a
• /
• pp.306-307
• /
• 2014

진공용 장비의 sealing 방법으로 Cu gasket을 이용한 CF type과 O-ring을 이용한 NW type이 있다. 이중 O-ring을 이용한 sealing 방법에는 clamp를 사용하게 되는데 Al 합금으로 제작된 clamp에 bellows의 수축 시 받는 전단응력과 전단응력한계 이상의 힘을 받았을 때의 clamp 파손에 따른 역압에 의한 TMP 손상 분석.

• Proceedings of the KSR Conference
• /
• 2000.05a
• /
• pp.626-633
• /
• 2000

An air spring which is a part of the railroad vehicle suspension system is used to reduce and absorb the vibration and the noise. Main components of the air spying are a cord reinforced rubber bellows, a upper plate, a lower plate and a stopper rubber spring. The characteristics of the air spring which are the load capacity, the vertical and the horizontal stiffness are depended on the configuration of rubber bellows, the angle of cord and the mechanical properties of cord. The computer simulation using commercial finite element analysis codes are executed to predict and evaluate the load capacity and the stiffness. The appropriate shape and cord angle of the air suing are selected to adjust the required performance of the air spring. Several samples of the air spring are manufectured and experimented. It is shown that the results by computer simulation are in close agreement with the test results.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2000.02a
• /
• pp.49-49
• /
• 2000

당사는 1991년 6월에 설립된 후 반도체 장비의 국산화 개발에 주력하고 있다. Thermoelectric module typer Chiller 및 Dry gas scrubber를 국산화 하였으며 THC(Temperature & Humidity Controller)를 개발하여 국내 및 미국에 특허를 출원중에 있으며 기업 부설연구소를 통해 계속하여 각종 제품을 연구 개발하고 있다. 이외 다수의 제품을 보유하고 있으며 기업 부설연구소를 통해 계속하여 각종 제품을 연구 개발하고 있다. 이외 다수의 제품을 보유하고 있으며 진공관련 제품으로는 미국 MDC사 Vacuum components, e-beam vaporation system. ISI사 electrical and optical components, US Inc. 사 Sputter system, SBC사 Bellows. 일본 IKC사 Bellows, Vacuum components, Vacuum system을 취급하고 있다. 1998년에 경기도 및 중소기업청으로부터 유망중소기업 및 벤처기업 인증을 획득하였으며 1999년 12월에 경기도 및 중소기업청으로부터 유망중소기업 및 벤쳐기업 인증을 획득하였으며 1999년 12월 KOSDAQ에 등록하였다. 중소기업 수출기업화 사업 대상기업으로 선정되었으며 1999년 12월 KOSDAQ에 등록하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.505-506
• /
• 2013

• Journal of Welding and Joining
• /
• v.30 no.2
• /
• pp.11-15
• /
• 2012

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2017.10a
• /
• pp.105-106
• /
• 2017

• Nuclear Engineering and Technology
• /
• v.46 no.3
• /
• pp.363-372
• /
• 2014

In this study, we proposed a newly designed sulfuric acid transfer system for the sulfur-iodine (SI) thermochemical cycle. The proposed sulfuric acid transfer system was evaluated using a computational fluid dynamics (CFD) analysis for investigating thermodynamic/hydrodynamic characteristics and material properties. This analysis was conducted to obtain reliable continuous operation parameters; in particular, a thermal analysis was performed on the bellows box and bellows at amplitudes and various frequencies (0.1, 0.5, and 1.0 Hz). However, the high temperatures and strongly corrosive operating conditions of the current sulfuric acid system present challenges with respect to the structural materials of the transfer system. To resolve this issue, we designed a novel transfer system using polytetrafluoroethylene (PTFE, $Teflon^{(R)}$) as a bellows material for the transfer of sulfuric acid. We also carried out a CFD analysis of the design. The CFD results indicated that the maximum applicable temperature of PTFE is about 533 K ($260^{\circ}C$), even though its melting point is around 600 K. This result implies that the PTFE is a potential material for the sulfuric acid transfer system. The CFD simulations also confirmed that the sulfuric acid transfer system was designed properly for this particular investigation.

• Journal of Biosystems Engineering
• /
• v.17 no.4
• /
• pp.305-313
• /
• 1992

Dynamic seals have been continue to be one of the major technical problems facing stirling engine designers. Most of the modern engines use some version of the dry ring seal for piston and displacer seals. Friction power losses associated with seals are typically several percent of gross output power, with piston ring seals usually being the main contributor. Much effort has been expended to develop the seal mechanism of piston, but the performance of these seal devices is very poor. This study was conducted to examine the efficiency of the various types of the trial-made piston seal mechanism with reference to leakage of working fluid and friction losses. This paper described the successful hardware implementation of a stainless steel bellows element in stirling engine application with test data in power performance. The indicated power by use of the bellows was more than two times as that by use of the piston ring types. As the result of this study, bellows was provide as a reliable and efficient seal mechanism for any stirling engine application.

• Journal of Biomedical Engineering Research
• /
• v.28 no.4
• /
• pp.569-576
• /
• 2007

Ventricular Assist Device(VAD) has switched its goal from a short-tenn use for bridge-to-transplantation to a long-tenn use for destination therapy, With this goal, the importance of long-tenn reliability gets more interests and importances, H-VAD is an portable extracorporeal biventricular assist device, and adopts an electro-pneumatic driving mechanism. The pneumatic pressure to pump out blood is generated with compression of bellows, and is transmitted in a closed pneumatic circuit through a pneumatic line. The existing pneumatic VAD adopts a air compressor which can generate stable pressures but has defects such as a noise and a size problem. Thus, it is not suitable for being used as a portable device, These problems are covered with adopting a closed pneumatic circuit mechanism with a bellows which has a small size and small noise generation, but it has defects that improper pneumatic setting causes a failure of adequate flow generation. In this study, the pneumatic pressure regulation system is developed to cover these defects of a bellows-type pneumatic VAD. The optimal pneumatic pressure conditions according to various afterload conditions for an optimal flow rate were investigated and the afterload estimation algorithm was developed, The final pneumatic regulation system estimates a current afterload and regulate the pneumatic pressure to the optimal point at a given afterload condition. The afterload estimation algorithm showed a sufficient performance that the standard deviation of error is 8.8 mmHg, The pneumatic pressure regulation system showed a sufficient performance that the flow rate was stably governed to various afterload conditions. In a further study, if a additional sensor such as ultrasonic sensor is developed to monitor the direct movement of diaphragm in a blood pump part, the reliability would be greatly increased. Moreover, if the afterload estimation algorithm gets more accuracy, it would be also helpful to monitor the hemodynamic condition of patients.