摘要:

MoS2films (300 to 400 Å) were radio-frequency sputtered on aluminum and nickel surfaces at elevated, ambient, cold water, and liquid nitrogen temperatures. Electron transmission micrographs and electron diffraction patterns were taken to determine the structural growth. These transmission micrographs revealed that sputtered MoS2films at ambient and elevated temperatures (320 and 150 C) formed an irregular network of ridges. The electron diffraction patterns of these films showed relatively sharp diffraction rings, indicating crystallinity. At water temperatures (∼7 C), ridge formation was extensively reduced or completely eliminated. The transmission micrographs of sputtered films at liquid nitrogen temperatures revealed a continuous featureless film. The electron diffraction patterns showed broad, diffused rings indicating an amorphous film. The transmission micrographs of a post annealed (425 C) MoS2film sputtered at liquid nitrogen temperature revealed the tendency for ridge formation. Electron diffraction patterns also showed increased sharpness of the diffraction rings.Presented at the 28th ASLE Annual Meeting in Chicago, Illinois, April 30–May 3, 1973

ISSN:0569-8197    

DOI:10.1080/05698197408981432

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

In sudden death testing, a group of bearings is divided into a number of equal-sized subgroups and tested only until the first failure occurs in each subgroup.

ISSN:0569-8197    

DOI:10.1080/05698197408981433

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Analytical and experimental work is presented to determine the nature of the coefficient of friction at the large rib roller end of a tapered roller bearing. The analytical work considers the dynamic equilibrium of a roller, and it is shown that for normal bearing speeds the inertial forces have negligible effect on the performance at the rib contact. Mathematical expressions for the frictional torque on a detached rib have been derived for the case of axially applied bearing loads.

ISSN:0569-8197    

DOI:10.1080/05698197408981434

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Optical EHD experiments in a ball-flat rig reveal that the degree of EHD fluid film starvation increases with both rolling speed and viscosity. Lubricant film starvation in rolling contacts is attributed to the insufficiency of fluid replenishment in the rolling path in the time interval between contacts. A film replenishment model is used to compute the film rebounding rate. The role of surface tension in contact lubrication is defined in terms of its effects on the rate of film replenishment. An analysis is presented using a depressed oil layer shape approximated by a deformed Hertzian point contact profile to predict the effect of upstream half-film height on the thickness of the plateau EHD film. A graph is obtained for the plateau film thickness as a function of the speed-viscosity parameter and a new starvation parameter proportional to oil-air surface tension and rolling element spacing. The result is in agreement with measured plateau film thickness in circular contact at different speeds for a realistic ambient layer thickness.Presented at the 28th ASLE Annual Meeting in Chicago, Illinois, April 30–May 3, 1973

ISSN:0569-8197    

DOI:10.1080/05698197408981435

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Sliding friction studies were conducted on an iron surface with exposure of that surface to various hydrocarbons and organic chlorides. The hydrocarbons included ethane, ethylene, ethyl chloride, methyl chloride and vinyl chloride. Auger cylindrical-mirror analysis was used to follow interactions of the hydrocarbon and organic chlorides with the iron surface. Results with vinyl chloride indicate friction-induced surface reactivity, adsorption to surface oxides, friction sensitivity to concentration and polymerization. Variation in the loads employed influence adsorption and, accordingly, friction. Unlike results with ethyl and vinyl chloride, friction-induced surface reactivity was not observed with ethane and ethylene.Presented at the 28th ASLE Annual Meeting in Chicago, Illinoir, April 30–May 3, 1973

ISSN:0569-8197    

DOI:10.1080/05698197408981436

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

A method of economically evaluating the hydrodynamic forces generated in a gas-lubricated tilting-pad bearing is presented. The numerical method consists of solving the case of the infinite width bearing and then converting this solution to the case of the finite bearing by accounting for end leakage. The approximate method is compared to the finite-difference solution of Reynolds equation and yields acceptable accuracy while running about one-hundred limes faster. A mathematical model of a gas-lubricated tilting-pad vertical rotor systems is developed. The model is capable of analyzing a two-bearing-rotor system in which the rotor center of mass is not at midspan by accounting for gyroscopic moments. The numerical results from the model are compared to actual test data as well as analytical results of other investigators.Presented at the 28th ASLE Annual Meeting in Chicago, Illinois, April 30–May 3, 1973

ISSN:0569-8197    

DOI:10.1080/05698197408981437

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

A recently developed ultrahigh-vacuum quartz spring mass sorption microbalance has been utilized to measure the evaporation rates of several low-volatility polymeric lubricating oils at various temperatures. The evaporation rates are used to calculate the vapor pressures by the Langmuir equation. A method is presented to accurately estimate extended temperature range evaporation rate and vapor pressure data for polymeric oils, incorporating appropriate corrections for the increases in molecular weight and the change in volatility of the progressively evaporating polymer fractions. The logarithms of the calculated data appear to follow linear relationships within the test temperature ranges, when plotted versus 1000/T. These functions and the observed effusion characteristics of the fluids on progressive volatilization are useful in estimating evaporation rate and vapor pressure changes on evaporative depletion.Presented at the 28th ASLE Annual Meeting in Chicago, Illinois, April 30–May 3, 1973

ISSN:0569-8197    

DOI:10.1080/05698197408981438

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Equations governing the steady-state thermohydrodynamic behavior of sector-shaped thrust bearings are solved numerically for an incompressible laminar flow of a Newtonian lubricant. The lubricant viscosity is taken as a function of the three-dimensional temperature distribution in the fluid film. Also, a general film thickness profile is allowed. Three dimensional heat transfer between the lubricant and both the moving and stationary solids is included in the analysis.

ISSN:0569-8197    

DOI:10.1080/05698197408981439

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor