TRIBOLOGICAL PROPERTIES OF A RUBBER SEAL UNDER OPERATION WITH OIL CONTAINING MoS2 NANOPARTICLES

Tribologia ◽  
2019 ◽  
Vol 286 (4) ◽  
pp. 95-103
Author(s):  
Wojciech SZCZYPIŃSKI-SALA ◽  
Agnieszka TOMALA ◽  
Janusz LUBAS
Keyword(s):  
Friction Force ◽  
Cross Section ◽  
Tribological Properties ◽  
Hydraulic Cylinder ◽  
Round Cross Section ◽  
Base Oil ◽  
Boundary Velocity ◽  
Mos2 Nanoparticles ◽  
Round Cross ◽  
Operation Characteristics

The issues associated with sealing operation are of vital significance due to their function in mechanics. The most universal, simple, and cheap solution of seals are O-rings. They are most commonly used for all seals. The article evaluates the operation characteristics of an O-ring seals under operation with oils containing MoS2 nanoparticles. The measurements were made on the sealing node model in a hydraulic cylinder where the round cross section seal cooperated with the piston rod. The changes of the friction force during rod movement resulting from the friction between the seal and the rod were analysed. The investigations presented in this paper allow one to conclude that, for the assumed research conditions, the average values of the friction force during instroke are higher for PAO oil with MoS2 additive in comparison to pure PAO base oil. In addition, the boundary velocity of the rod above in which the decrease of friction force was observed is higher for pure PAO oil.

scholarly journals Tribological Characteristic of a Ring Seal with Graphite Filler

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 311 ◽  
Author(s):  
Wojciech Szczypinski-Sala ◽  
Janusz Lubas
Keyword(s):  
Friction Force ◽  
Cross Section ◽  
Graphite Powder ◽  
Tribological Characteristic ◽  
Round Cross Section ◽  
Rod Model ◽  
Ring Seal ◽  
Synthetic Graphite ◽  
Materials Used ◽  
Round Cross

This paper presents the outcome of the measurement of the tribological characteristic of O-ring seals in the event of operating in conditions with a lack of lubrication. The measurement was carried out on a seal and rod model. The measurement was carried out during the condition of the round cross-section seal sliding on the surface of the piston rod. We analyzed how the friction force during rod movement, which resulted from the cooperation of the sliding nod and the rod, was changing. The experiment was conducted for various rubber materials. The aim of the research was to evaluate the friction reducing capability of graphite in rubbers of commercial sealing parts. Typical materials used for the seal and the materials, which contained the filler in the form of graphite powder, were compared. Synthetic graphite powder with a particle size of 1–2 µm was applied, and nitrile rubber (NBR) and fluoroelastomer (FKM) were compared as typical materials for O-ring seals. In the case of the two tested materials, the addition of graphite powder had an influence on the decrease in the friction force.

EVALUATION OF TRIBOLOGICAL PROPERTIES OF SEALS RUNNING IN CONTACT WITH VEGETABLE OIL

Tribologia ◽  
2017 ◽  
Vol 276 (6) ◽  
pp. 95-103
Author(s):  
Wojciech SZCZYPIŃSKI-SALA ◽  
Janusz LUBAS
Keyword(s):  
Friction Force ◽  
Vegetable Oils ◽  
Chemical Properties ◽  
Hydraulic Cylinder ◽  
Acid Mixture ◽  
Round Cross Section ◽  
Mineral Oils ◽  
Oxidative Gelation ◽  
Physical And Chemical ◽  
Round Cross

The article describes the results of the measurement to evaluate the operation characteristic of o-ring seals in case of the operation with vegetable oils. The measurements were made on the model of a sealing node in hydraulic cylinder, where the round cross section seal cooperated with the piston rod. The changes of the friction force during rod movement resulting from the friction between the seal and the rod were analysed. The tests were carried out with two vegetable oils mostly used in industry: rape oil and soybean oil. The products based on vegetable oils can be an alternative to products made on the basis of petroleum. However, vegetable oils are characterized by other properties than mineral oils. The physical and chemical properties of vegetable oils depend on the composition of the fatty acid mixture. The observation of the influence of the occurrence of oxidative gelation on friction force was also conducted. In case of vegetable oils, oxypolymerization tendencies of these fluids are a very significant factor, which can influence the characteristics of friction nodes operation.

An Iron Anthropoid Sword from Shouldham, Norfolk with Related Continental and British Weapons

1956 ◽  
Vol 21 ◽  
pp. 198-227 ◽  
Author(s):  
R. R. Clarke ◽  
C. F. C. Hawkes
Keyword(s):  
Cross Section ◽  
Kind Permission ◽  
Human Skeleton ◽  
Round Cross Section ◽  
Unequal Size ◽  
Arable Field ◽  
Medieval Church ◽  
The Reformation ◽  
Round Cross

An iron sword of anthropoid-hilted type (pl. XXIV, 1, 3) was found in 1944 at Shouldham in West Norfolk, some five miles east of the margin of the Fens, and since 1949 has been on loan to Norwich Castle Museum. It is here published by kind permission of the owner, Mr W. R. O. Woodward. The sword was discovered while gravel was being dug in an arable field about 200 feet south-east of the site of the medieval church of St. Margaret, which fell into ruins after the Reformation. The sword was found at a depth of 1 foot 6 inches lying across the chest of an extended human skeleton inside the boundary of the medieval churchyard, as graves of that period were found adjacent though they had not disturbed this pre-Christian inhumation. There is no indication either on the ground or on air-photographs that a barrow had formerly existed, and the burial is probably to be regarded as an isolated interment.The overall length of the sword, to the end of the branching arms, is now 21⅜ in. (54 cm.), but this has been slightly diminished by corrosion. The straight-edged blade is 16⅜ in. (44 cm.) long and the hilt measures 3¼ in. (8 cm.). At both ends of the hilt curving arms of round cross-section branch outwards to end in knobs, now of unequal size owing to differential rusting. The surface of the grip bears traces of transverse ribbing, perhaps imitating that found in bronze on other examples of the type.

scholarly journals Spatial Spectroscopy Approach for Detection of Internal Defect of Component without Zero-Position Sensors

2016 ◽  
Vol 2016 ◽  
pp. 1-5
Author(s):  
Qizhou Wu ◽  
Yong Jin ◽  
Zhaoba Wang ◽  
Zhaoqian Xiao
Keyword(s):  
Cross Section ◽  
Biological Tissues ◽  
Noninvasive Detection ◽  
Object Surface ◽  
Internal Defect ◽  
Round Cross Section ◽  
X Ray ◽  
Zero Position ◽  
Round Cross ◽  
Distance Signal

Conventional approach to detect the internal defect of a component needs sensors to mark the “zero” positions, which is time-consuming and lowers down the detecting efficiency. In this study, we proposed a novelty approach that uses spatial spectroscopy to detect internal defect of objects without zero-position sensors. Specifically, the spatial variation wave of distance between the detecting source and object surface is analyzed, from which a periodical cycle is determined with the correlative approaches. Additionally, a wavelet method is adopted to reduce the noise of the periodic distance signal. This approach is validated by the ultrasound detection of a component with round cross section and elliptical shape in axis. The experimental results demonstrate that this approach greatly saves the time spent on the judgment of a complete cycle and improves the detecting efficiency of internal defect in the component. The approach can be expanded to other physical methods for noninvasive detection of internal defect, such as optical spectroscopy or X-ray scanning, and it can be used for hybrid medium, such as biological tissues.

scholarly journals Pulsation parameters of new and used milking liners with round cross section

2021 ◽  
Vol 13 (3) ◽  
pp. 288-291
Author(s):  
G. Dineva ◽  
K. Peychev ◽  
D. Georgiev
Keyword(s):  
Service Life ◽  
Cross Section ◽  
Holstein Cattle ◽  
Frequency Range ◽  
Round Cross Section ◽  
Round Cross

Abstract. Milking machines equipped with new and used milking liners with a round cross section were studied. The used milking membranes were operated for 3 months on a farm for rearing 60 cows (Holstein cattle) with double milking per day. The experiment involved recording the standard pulsation phases “a”, “b”, “c” and “d” (in absolute units) in the frequency range from 1 Hz to 2.5 Hz, in a vacuum mode of 40 kPa and 50 kPa and at a pulsation ratio of 50/50%. It was found that the transients (phase “a” and phase “c”) are faster and the established phases (phase “b” and phase “d”) are longer in milking units equipped with used milking liners. The conclusions are related to the service life of the milking liners.

scholarly journals Correction: Ungson, Y. et al. Filling of Irregular Channels with Round Cross-Section: Modeling Aspects to Study the Properties of Porous Materials. Materials 2018, 11, 1901

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 818
Author(s):  
Yamel Ungson ◽  
Larysa Burtseva ◽  
Edwin Garcia-Curiel ◽  
Benjamin Valdez Salas ◽  
Brenda Flores-Rios ◽  
...  
Keyword(s):  
Porous Materials ◽  
Cross Section ◽  
Round Cross Section ◽  
Round Cross

The authors have found two errors in the paper published in Materials [...]

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