摘要:

Work in the field of gear tooth surface distress during recent years has shown clearly that surface temperature history provides the key to performance predictions. This especially applies when using an EP oil.

ISSN:0569-8197    

DOI:10.1080/05698197508982765

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

A new ball fatigue tester, the Twin-Head Five-Ball Machine, developed in order to study the effect of traction and sliding on fatigue life, is described in detail. The novel features offered by the apparatus are presented and their implications discused.

ISSN:0569-8197    

DOI:10.1080/05698197508982766

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

A capillary viscometer was used to measure viscosity as a function of pressure, temperature, and shear stress for a number of lubricants. Measurements were made at 38 C, 99 C, and 149 C (100 F, 210 F, and 300 F), gauge pressure to 5.5 × 108N/m2(8 × 104psi), and shear stresses to 106N/m2(14.5 psi). At 38 C (100 F), the order of the pressure-viscosity coefficients for the unformulated fluids was: fluorinated polyether > synthetic hydrocarbon > naphthenic mineral oil > synthetic paraffinic oil (lot 4) > C-ether ≅ synthetic paraffinic oil (lot 3) > polyalkyl aromatic > advanced ester. All pressure viscosity coefficients decreased with increasing temperature. Fair agreement was obtained when pressure-viscosity coefficients at 38 C (100 F) and 6.9 × 107N/m2(104psi) were compared to data from other investigators using different techniques (optical elastohydrodynamics, oscillating crystal, and low shear capillary viscometry).Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference held in Montreal, Canada, October 8–10, 1974

ISSN:0569-8197    

DOI:10.1080/05698197508982767

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Metal surfaces have been investigated after lubrication tests with oils containing solid lubricants. With an MoS2-containing engine oil, an MoS2-film was formed on engine parts. Solids without a layer structure also formed solid films on metal surfaces at the area of frictional contact. These films are, however, not the original compounds, but products of chemical reaction.Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference held in Montreal, Canada, October 8–10, 1974

ISSN:0569-8197    

DOI:10.1080/05698197508982768

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The friction-temperature characteristics of a series of lubricated copper-tin solid solutions are investigated on a modified four-ball machine. Heats of adsorption of the polar component of the lubricant onto the alloy surfaces are measured by a critical temperature method. These are not found to be a simple function of the bulk tin content of the alloys as would be expected intuitively. Electron probe microanalysis of the wear scars of the alloys reveals that tin atoms migrate towards the worn surfaces during the friction tests, most probably by an interaction with dislocations. The average tin contents (within the depth penetrated by the probe) appear to control the values of the heats of adsorption. It is suggested that, in many cases, bulk compositions should not be expected to hold near worn surfaces.Presented at an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference held in Montreal, Canada, October 8–10, 1974

ISSN:0569-8197    

DOI:10.1080/05698197508982769

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Pivotal hammer type impact testers are used in an experimental study of repetitively impacted lubricated contacts. Various steels are used in one- and two-body wear modes; the rate process of wear is investigated with respect to the impact parameters (normal and tangential approach velocity), and lubricant viscosity. For normal impact, a boundary lubrication system forms, but superimposed sliding speeds with a viscous lubricant tend to create an elastohydrodynamic lubrication (EHL) condition, greatly resisting wear. Approximate measurable wear equations are derived for cylindrical striking surfaces.Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference held in Montreal, Canada, October 8–10, 1974

ISSN:0569-8197    

DOI:10.1080/05698197508982770

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

A fracture mechanics technique has been used to determine the rate of fatigue crack propagation in rotating-beam SAE 52100 steel specimens in several lubricating environments. Experiments were conducted in a mineral and antiwear hydraulic oil under wet and dry conditions, a water-in-oil emulsion, distilled water, and air. Differences as high as 8:1 in crack propagation rates were observed among these environments; the differences were found to depend on the magnitude of the stress-intensity factor at the crack tip. A method is outlined for separating the crack initiation stage from the propagation stage in rotating-beam specimens. This method is expected to provide new insights regarding the chemical influence of lubricants on the mechanisms responsible for fatigue crack development in bearings.Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference held in Montreal, Canada, October 8–10, 1974

ISSN:0569-8197    

DOI:10.1080/05698197508982771

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

An optical interference method was used to display the distorted film shape in nominally parallel surface thrust washers. The bearings were made of aluminium to accentuate thermal expansion and were carefully lapped flat before use. Both the experimental results and an analysis of the coupled elasticity, Reynolds and energy equations confirm that these bearings operate by the formation of a slightly converging film over the leading 80 percent (or less) of the pad. Fair agreement was obtained between the analysis and previously developed multiple regression equations. Thrust washers for industrial use with random waviness are likely lo perform better than lapped bearings.Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference held in Montreal, Canada, October 8–10, 1974

ISSN:0569-8197    

DOI:10.1080/05698197508982772

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

A model is presented here to predict the maximum frequency attainable for a typical noncontacting face seal (for gas service) to be run successfully in the presence of axial runoul. This work has been carried out because the determination of maximum allowable speed by laboratory testing results in serious and costly damage to seal rings.

ISSN:0569-8197    

DOI:10.1080/05698197508982773

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor