摘要:

Data are presented showing the effect of the surface condition of metals and ceramics on wear at high temperatures (280°C). When cast iron is heated to 280°C and subjected to reciprocating wear, a layer of Fe3O4is formed on the surface which has a high coefficient of friction (0.68) and a high wear rate. To reduce this wear, a vapor stream of 0.1 percent tricresyl phosphate (TCP) and nitrogen was continuously delivered to the contact region between the pin and reciprocating plate. The coefficient of friction was reduced to 0.1 and the wear rate was essentially zero.

ISSN:1040-2004    

DOI:10.1080/10402009208982092

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The need for a methodology to determine the stiffness characteristics of elastomeric seals with complex geometry has prompted an investigation using a commercially available finite element code. Axial and radial compression of O-rings, as well as the influence of restraining grooves and friction, are investigated. Axisymmetric analyses are performed, and their results are compared with those obtained by other researchers who assumed plane strain conditions. The differences in the results of the axisymmetric and plane strain loading conditions increase with the level of compression, except for one loading case. The method of reduced integration is shown to effectively handle the problem of high localized hydrostatic stresses, which are especially enhanced in confined geometries, and to provide accurate results. Stiffness characteristics of O-ring seals having a range of geometric and material properties are given in a nondimensional form. This form allows for general modeling of the O-ring stiffness as a force and a spring at compression (i.e., deformation) levels up to 32 percent.Presented at the 46th Annual Meeting in Montreal, Quebec, Canada April 29–May 2, 1991

ISSN:1040-2004    

DOI:10.1080/10402009208982093

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The rolling contact fatigue and sliding wear performance of two types of ferritic nitrocarburizing techniques (gaseous and fluidized bed) were evaluated on AISI M-50 steel. These processes produced a thin compound layer over a nitrogen-rich diffusion zone. It was observed that compound layer thicknesses less than 1 μm increased the rolling contact fatigue (RCF)L10life up to a factor of six over the untreated M-50 steel. Compound layers greater than 2 μm had a tendency to flake off the substrate near the spalled region, producing lowerL10lives than the baseline M-50 steel. Sliding wear tests on ferritic nitrocarburized M-50 showed that the compound layer exhibited slightly larger friction coefficients than the nitrogen-rich diffusion zone, although this layer had slightly greater resistance to catastrophic wear at higher contact stresses.Presented at the 46th Annual Meeting in Montreal, Quebec, Canada April 29–May 2, 1991

ISSN:1040-2004    

DOI:10.1080/10402009208982094

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A numerical study is performed of oil groove type (circumferential and axial), groove number (single and double) and groove location on journal bearing performance. The analysis involves the use of a cavitation algorithm. The interaction between cavitation phenomena and grooving is determined. Quantitative information is provided which will aid designers to better locate oil feed grooves.Presented at the 45th Annual Meeting in Denver, Colorado May 7–10, 1990

ISSN:1040-2004    

DOI:10.1080/10402009208982095

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The velocity dependence of disk lifetime and temperature rise before failure during a pin-on-disk type sliding test on coated magnetic disks was investigated in detail

ISSN:1040-2004    

DOI:10.1080/10402009208982096

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The rheological properties of two powder lubricants mixed separately with ethylene glycol were determined experimentally. The two powder lubricants were graphite and molybdenum disulfide. Bingham plastic, power law and hyperbolic rheological models were compared with the experimentally determined shear stress-shear rate rheological data. All three models compare favorably with experimental data at high shear rates. The power law and hyperbolic rheological models are realistic candidates at low shear rates. The three rheological models were incorporated into fluid flow equations and solved for the case of pressure induced flow between parallel surfaces. Predicted flow rates of these non Newtonian slurries were checked against laboratory data which was obtained through a test rig designed and built during the study.Presented at the 46th Annual Meeting in Montreal, Quebec, Canada April 29–May 2, 1991

ISSN:1040-2004    

DOI:10.1080/10402009208982097

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The present paper extends the dislocation dipole accumulation model to describe crack initiation in contact fatigue. The fatigue life under contact loading is calculated from an elastic solution. The plastic deformation may be taken into account by considering multi-slip layers. The present calculations show a qualitative consistency with experimental observations, although some additional parameters, such as the reversibility of dislocation pileup, are needed to make the theoretical prediction more comparable to the experimental data.Presented at the 46th Annual Meeting in Montreal, Quebec, Canada April 29–May 2, 1991

ISSN:1040-2004    

DOI:10.1080/10402009208982098

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Two new methods for releasing the adhesion of flying head sliders to hard magnetic disks are proposed. The first is to heat the slider electrically and the second is to heat the atmosphere in a hard disk drive. It has been experimentally confirmed that both methods are effective in reducing the adhesive force between the slider and the magnetic disk. These methods reduce the surface tension of water and lubricant and eliminate water which intervenes between the slider end the disk. The first method also minimizes the contact area between the slider and the disk. A technique for estimating the evaporation rate of water is proposed and is confirmed experimentally.Presented as a Society of Tribologists and Lubrication Engineers paper at the ASME/STLE Tribology Conference in Toronto, Ontario, Canada, October 8–10, 1990

ISSN:1040-2004    

DOI:10.1080/10402009208982099

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Numerical analysis of elastohydrodynamic lubrication of piston rings requires that the solutions are able to converge quickly. In this paper, a new powerful numerical method, the Multigrid method, has been introduced, and the numerical problem has been solved successfully. The computing process and practice are expounded. In addition, a new radial force equilibrium equation taking the internal force into account has been proposed and a more precise formula for calculating the radial displacement has been used. Both of these make the calculations more accurate. The oil film thickness values presented in this paper have been compared with those published before. It can be shown that former values are closer to the measured values.

ISSN:1040-2004    

DOI:10.1080/10402009208982100

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The flow field within the lubricating film of a mechanical seal containing shallow grooves is investigated analytically. Numerical solutions of the Reynolds equation show that groove patterns extending across the entire seal face, with depths on the order of microns, can significantly affect the flow field. Cavitation plays an important role in this process. Oblique grooves and spiral grooves are evaluated, with emphasis on their ability to reduce or eliminate leakage.Presented at the 46th Annual Meeting in Montreal, Quebec, Canada April 29–May 2, 1991

ISSN:1040-2004    

DOI:10.1080/10402009208982101

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor