Sealing Performance Analysis of Cap Seal Rings in the Stirling Engine Piston Rod

2014 ◽  
Vol 697 ◽  
pp. 206-209
Author(s):  
Jun Chang

When the Stirling engine piston rod for reciprocating motion at a high speed under dry friction conditions, the temperature fall or pressure drop is mainly caused by uneven sealing ring deformation, increased wear and sealing performance fall. This article is introduced a cap seal rings of Stirling engine piston, study for friction and wear in theory under dynamic seal condition, and establish a rod seal test equipment to analysis the cap seal structure distortion and gauge wear in different working environments by experimental methods. Finally, come to the conclusion that when working medium pressure at 7 mpa, the cap seal performance is best.Keywords: Rod seal; cap seal structure; stress analysis

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Chuanjun Han ◽  
Han Zhang ◽  
Jie Zhang

In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficient, and material parameters on sealing performances were discussed. The results show that von Mises stress of the biomimetic sealing ring distributed symmetrically in no-pressure static sealing. The maximum von Mises stress appears on the second bulge of the inner side. High contact stress concentrates on left bulges. Von Mises stress distribution becomes uneven under medium pressure. Both von Mises stress and contact stress increase when precompression, medium pressure, and rubber hardness increase in static sealing. Biomimetic ring can avoid rolling and distortion in reciprocating dynamic seal, and its working life is much longer than O-ring and rectangular ring. The maximum von Mises stress and contact stress increase with the precompression, medium pressure, rubber hardness, and friction coefficient in reciprocating dynamic seal.


Mechanika ◽  
2020 ◽  
Vol 26 (4) ◽  
pp. 338-345
Author(s):  
Yang HU ◽  
Jie ZHANG ◽  
Li Ming CHEN

In this paper, the non-smooth surface technology is applied to the surface structure of the rectangular sealing ring, and a bionic sealing ring is designed. Two-dimensional axisymmetric models of rectangular and bionic sealing rings were established. Effects of pre-compression amount, fluid pressure, friction coefficient and reciprocating velocity on the static and dynamic sealing performance of two sealing rings were studied. The results show that the seal performance of the bionic sealing ring is greater than that of rectangular. The static seal performance increases with the increasing of fluid pressure and compression amount. Dynamic sealing performance in outward stroke is better than it in the inward stroke. Friction coefficient has a smaller effect on the bionic sealing ring’s sealing performance than rectangular sealing ring. Therefore, using the bionic sealing ring can improve the static and dynamic seal performances and prolong its service life in hydraulic systems, rotating machinery and reciprocating machinery.


2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Jie Zhang ◽  
Jingxuan Xie

Rubber O-rings are widely applied in the static and dynamic seals of machinery, energy, chemical, aviation, and other fields. Mechanical behavior and sealing performance of the O-ring were investigated in this paper. Effects of precompression amount, fluid pressure, friction coefficient on the static and dynamic sealing performances of the O-ring were studied. The results show that the maximum stress appears on the inside but not surface of the O-ring. The static sealing performance increases with the increasing of fluid pressure and compression amount. Reciprocating dynamic sealing performance of the rubber O-ring is different with its static sealing performance; the stress distribution and deformation are changing in reciprocating motion. Sealing performance in outward stroke is better than it in the inward stroke. Overturn of the O-ring occurs when the friction torque is greater than the torque that caused by fluid pressure in the inward stroke. Distortion, bitten, and fatigue failure are the main failure modes of the O-ring in the dynamic seal. Those results can be used in design, installation, and operation of rubber O-rings in static and dynamic seals.


2011 ◽  
Vol 194-196 ◽  
pp. 2420-2424
Author(s):  
Guo Li Zhang ◽  
Ya Nan Wang ◽  
Jia Lu Li ◽  
Guang Wei Chen ◽  
Li Chen ◽  
...  

In order to investigate the effect of different reinforcement structure on the dynamic characteristics of sandwich structure composite plates used for manufacturing the high speed reciprocating motion composite components, four kinds of paulownia wood sandwich composite test specimens with dimensions of 350×83.5×9.5mm was designed and made by hand lay-up performing and press molding technology. The woven and 2D braiding fabric prepreg were both selected as top face and inner face materials , respectively, and the carbon fiber woven fabric prepreg was chosen as inner part materials. According to the impulse response modal test method, a modal test system was established. It was found that this kind of sandwich structure composite plate has bigger natural frequency value, it’s minimum natural frequency was about 609.77Hz that could meet the requirement for high speed reciprocating motion parts. The dynamic test results shown that the natural frequency of F2BAF-IUC-CPW sample is higher t about 11.17% at least, selecting 2D integral braiding pipe fabric as top face and inner face reinforced materials could effectively improve the dynamic properties of sandwich composite rectangular plates. The modal experiments indicated that the modal shapes of sandwich composite plate specimen with four kind reinforcement structures were identical, it’s 1st modal shape, 2nd modal shape and 3rd modal shape presented torsional vibration shape, flexural vibration shape and torsional flexural vibration shape, separately, the modal shapes of sandwich composite plate specimen were not obviously affected by reinforcement structure.


Author(s):  
L Brzeski ◽  
Z Kazimierski

This paper presents a new concept of the externally heated valve (EHV) engine. Air can be used as a working medium in the closed cycle of this engine. Heat delivered to the working air can come from a combustion chamber or another heat generator of an arbitrary type. The engine construction and the thermodynamic cycle performed by it are original and entirely different from the well-known Stirling engine. The main disadvantage of the Stirling engine is its low power density, that is the low power obtained per litre of the engine cylinder volume. In the case of the engine presented here it is possible to achieve power density and efficiency similar to those typical of advanced internal combustion engines. Comparisons between the power of the Stirling engine and the power of the new engine have been performed for the same engine capacity, rotational frequency and maximum and minimum temperatures of the cycle. At the same minimum pressure of the working gas in both engines, the power of the EHV engine is several times higher than that of the Stirling engine, while, on the other hand, at the same maximum pressure of the working gas in both engines, the power of the EHV engine is 20 per cent higher than that of the Stirling engine power. The efficiencies of both engines do not differ significantly from each other.


Author(s):  
Shuxiang Guo ◽  
Liwei Shi

Given the special working environments and application functions of the amphibious robot, an improved RGB-D visual tracking algorithm with dual trackers is proposed and implemented in this chapter. Compressive tracking (CT) was selected as the basis of the proposed algorithm to process colour images from a RGB-D camera, and a Kalman filter with a second-order motion model was added to the CT tracker to predict the state of the target, select candidate patches or samples, and reinforce the tracker's robustness to high-speed moving targets. In addition, a variance ratio features shift (VR-V) tracker with a Kalman prediction mechanism was adopted to process depth images from a RGB-D camera. A visible and infrared fusion mechanism or feedback strategy is introduced in the proposed algorithm to enhance its adaptability and robustness. To evaluate the effectiveness of the algorithm, Microsoft Kinect, which is a combination of colour and depth cameras, was adopted for use in a prototype of the robotic tracking system.


Author(s):  
Sanjay Mohan ◽  
Ankush Anand ◽  
R. Arvind Singh ◽  
S. Jayalakshmi ◽  
Xizhang Chen ◽  
...  

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