• 제목/요약/키워드: sliding resistance

검색결과 323건 처리시간 0.023초

크롬 도금한 유압 실린더 로드와 시일 사이의 미끄럼접촉 해석 (Sliding Contact Analysis between Chromium Plated Hydraulic Cylinder Rod and Seals)

  • 박태조;김민규
    • 드라이브 ㆍ 컨트롤
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    • 제15권1호
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    • pp.10-15
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    • 2018
  • The hydraulic cylinder seals are used not only to protect leakage of the working fluids but also to prevent incoming of foreign particles into the system. Chromium plating is generally applied to improve corrosion and wear resistance. It has been noticed that sealing surface damage occurs due to the hard foreign/wear particles contained in the hydraulic oil. In this study, a three-bodied sliding contact problem related with a PTFE seal, a spherical particle and chrome-plated steel substrate is modeled to investigate the relations to wear mechanism. Using the nonlinear finite element software, MARC/MENTAT, the deformed shapes, the von Mises and first principal stress distributions with plating thickness were compared. The sealing surface was mainly abraded by hard particles embedded in the seal. The plastic deformation of the steel substrate decreased with thicker plating. Hence it could be more effective to coat the sealing surface of a hydraulic cylinder with a hard material such as TiN, TiC and DLC.

Sliding Wear of Alumina-silicon Carbide Nanocomposites

  • Kim, Seung-Ho;Lee, Soo-Wohn;Kim, Yun-Ho;Riu, Doh-Hyung;Tohru Sekino;Koichi Niihara
    • 한국세라믹학회지
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    • 제38권12호
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    • pp.1080-1084
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    • 2001
  • Alumina-based nanocomposites have improved mechanical properties such as hardness, fracture toughness and fracture strength compared to monolithic ceramics. In this study, alumina with 5 vol% of nanosized SiC was sintered by a hot pressing technique at 1600$\^{C}$, 30 MPa for 1h in an argon gas atmosphere. Microstructures and mechanical properties in alumina-SiC nanocomposite were investigated. Moreover, tribological properties in air and water were compared each other. Relationships of wear properties with mechanical properties such as hardness, strength, and fracture toughness as well as microstructure were studied. Based on experimental results it was found that nanosized SiC retarded grain growth of matrix alumina. Mechanical properties such as hardness, fracture toughness and strength were improved by the addition of nanosized SiC in alumina. Improved mechanical properties resulted in increased sliding wear resistance. Tribological behavior of nanocomposites in water seemed to be governed by abrasive wear.

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마찰재에 함유된 금속섬유의 종류에 따른 마찰 특성 (Tribology of friction materials containing different metal fibers)

  • 고길주;장호
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2001년도 제33회 춘계학술대회 개최
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    • pp.55-63
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    • 2001
  • Friction and wear properties of brake friction materials containing different metal fibers (Al, Cu or Steel fibers) were investigated using a pad-on-disk type friction tester. Two different materials(gray iron and Al-MMC)) were used for disks rubbing against the friction materials. Results from ambient temperature tests revealed that the friction material containing Cu fibers sliding against cast iron disk showed a distinct negative ${\mu}$-ν (friction coefficient vs. sliding velocity) relation implying possible stick-slip generation at low speed. The negative ${\mu}$-ν relation was not observed when the Cu-containing friction materials were rubbed against the. Al-MMC counter surface. As applied loads increased, friction materials showed higher friction coefficients comparatively. Friction materials slid against cast iron disks exhibited higher friction coefficients than Al-MMC disks during high temperature tests. On the other hand, high temperature test results suggested that copper fibers in the friction material improved fade resistance and the steel fibers were not compatible with Al-MMC disks showing severe material transfer and erratic friction behavior during sliding at elevated temperatures.

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건축물 바닥재의 마모에 따른 미끄럼성능 변동에 관한 연구 (A Study on the Change of Slipperiness of Building Floor-coverings by Friction Wear)

  • 신윤호;최수경
    • 한국건축시공학회지
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    • 제5권1호
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    • pp.53-61
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    • 2005
  • The purpose of this study presents useful data on the choice or development of floor covering from slip viewpoint by examining closely the impact of the changes in sliding experiments due to the wear of floor covering by walk. The result of wear practical test per ten thousand walks enforces some kind of popular floor covering and measure of coefficient of slip resistance as follows: (1) When surface of floor covering is in the state of wet, the degree of wear doesn't affect greatly in slip. (2) When surface of floor covering is in dry and clean state, most floor coverings have the tendency to lower the coefficient of slip resistance with the amount of walk on it. (3) Change in the tendency of slip resistance by wear appeared mainly due to the differences in the state of floor covering and organic floor covering appeared to have great reduction of coefficient of slip resistance than the inorganic ones. (4) According to the result of investigation on changes in tendency of coefficient of slip resistance due to the increase in the number of walk and if two hundred thousand walks were done, regardless of surface shape or kind of site, etc, the safety of floor covering, in slip viewpoint, greatly reduces.

미끄럼 저항 측정을 위한 로봇 시스템 개발 (The Development of Robot System for Assessing Slip Resistance)

  • 김정수
    • 한국안전학회지
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    • 제28권5호
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    • pp.1-4
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    • 2013
  • The main objective was to design and develop a prototype robot system for assessing slip resistance. The developed robot system will be able to be used for stochastic nature of friction in the whole workplace. The second objective was to evaluate its operating condition in the laboratory, using a dreg sled type slipmeter(BOT-3000) as reference device. It was found that COF(Coefficient of Friction) measured with robot system was similar to that of BOT-3000 when sliding velocity was reached at 0.2m/s. The robot system might be the more promising one than any traditional measurement devices. A further evolution of prototype devices, as well as the development of test methods for that's various applications, is to be started in forthcoming studies.

Effect of surface Treatment on Piston Wear in the Oil Hydraulic Piston Pump

  • Kim, Jong Ki;Park, Kyung Min;Oh, Seok Hyung;Jung, Jae Youn
    • KSTLE International Journal
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    • 제2권1호
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    • pp.17-21
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    • 2001
  • Surface treatment technologies are frequently used to improve mechanical properties of surface layers of machinery components in many practical situations. Surface hardness of piston in the oil hydraulic piston pumps is very important about wear resistance. To improve hardness, wear resistance of the oil hydraulic axial piston pump, it is needed to know the surface layer characteristics in the sliding contact parts. This paper reports an experimental study on surface treatment characteristics in the piston of the oil hydraulic axial piston pump. We investigated the surface wear of a piston between untreated and nitriding-treated surfaces. We obviously observed that the surface hardness of piston in the oil hydraulic axial piston pump plays an important role to have wear resistance and remain a longer life.

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B.390 알루미늄 합금의 마모특성에 미치는 초정Si 입자크기와 잔류응력의 영향 (Effect of Primary Si size and Residual Stress on the Wear Properties of B.390 Al Alloys)

  • 김헌주;김성재
    • 열처리공학회지
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    • 제19권1호
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    • pp.20-29
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    • 2006
  • Wear behaviour of B.390 aluminum alloy with different particle sizes of primary Si against a SM45C counterface was studied as a function of wear load and sliding velocity, using pin-on-disk apparatus under dry condition. The wear rate of specimen with fine primary Si particles showed increased wear resistance at high wear load, on the other side wear resistance of coarse primary Si particle size was improved at low wear load. As the compressive residual stress in the matrix increased remarkably by liquid nitrogen(LN) treatment, wear resistance of the LN treated specimen was more excellent than that of T6 treated specimen.

토사마모실험을 통한 고크롬철계 주조합금의 내마모성 평가 (The Estimate of Abrasion resistance of High chromium white cast irons by Dry sand/rubber wheel tester)

  • 김상호;김기열;이범주;조정환;박채규
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 1998년도 제28회 추계학술대회
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    • pp.38-48
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    • 1998
  • To apply the high chromium white cast irons for sliding parts of construction equipments, the wear characteristics of these alloys which have three kinds of microstructure(hypoeutectic, near-eutectic, hypereutectic) were investigated by dry sand/rubber wheel tester. Also, the effect of heat treatment was investigated for the same alloys. As result of the test, heat treatment have no effect on the wear characteristics. And, hypereutectic composition alloy has the highest wear resistance against SiO$_2$. Also after test, cracking was observed in eutectic and primary carbides of all materials tested. This phenomenon was important factor in the wear resistance.

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표면개질을 달리한 자동차 변속기어의 마멸특성 비교 (Comparision of Wear Characteristics of Automobile Transmission Gear on Surface Modification)

  • 류을현;조연상;김영희;박흥식
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2003년도 학술대회지
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    • pp.299-306
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    • 2003
  • The SCM420 used mainly to automobile transmission gear has problems that it costs transmission gear maker much money in carburizing treatment. For this, it needs to alternate the existing material and heat treatment to new gear material and surface modification. For this, friction and wear experiment according to sliding speed and applied load was carried out to evaluate the wear resistance of two transmission gear materials with oxidation nitrocarburising and non-oxidation nitrocarburising NT100, The presumed wear volume was calculated with the image processing for evaluation of wear resistance of two transmission gear materials. The results show that the oxidation nitrocarburising has a distinguished wear resistance than non-oxidation nitrocarburising.

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Aluminum Engine Cylinder Bore 적용 AlSiMg/SiC 복합 용사피막의 내마모 특성 (Wear Resistance Characteristics of Thermal Sprayed AlSiMg/SiC Composite Coatings on Aluminum Engine Cylinder Bores)

  • 양병모;변응선;박경채
    • Journal of Welding and Joining
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    • 제17권6호
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    • pp.62-69
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    • 1999
  • The advantages of Thermal sprayed coatings as a replacement for cast iron liners are reduced weight, better heat transfer and reduced cost. One of the most important performance attributes of a cylinder bore coating is its wear resistance, since it must survive the abrasive sliding of both the piston rings and the piston skirt. In this study, composite powders were prepared by ball milling of Al-13Si-3Mg(wt%) alloy with SiC particles. The concentrations of SiC were 40 and 60wt%. The composite powders were sprayed using Metco-9MB plasma torch. Plasma sprayed coatings were heat-treated at 500℃ for 3 hours. The wear resistances of the plasma sprayed coatings were found to improve with heat treatment and superior to the commercially available G.C.I.(gray cast iron). AlSiMg-40SiC heat-treated coatings showed the best wear resistance in this study.

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