摘要:

This paper presents the result of pressure measurements made in hydrostatic and squeeze-film bearings lubricated with a powder-lubricant slurry. The powder lubricant was powdered graphite and the carrier fluid was ethylene glycol. Pressure measurements compared favorably with analytical predictions based on a power law rheological model.

ISSN:1040-2004    

DOI:10.1080/10402009408983366

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A potentially powerful effect on the characteristics of plain journal bearings is local thermal deformation of the bearing surface. Although there are a few analyses that consider the effect, it is ignored by most journal bearing codes used by industry. There is also almost no experimental data in the literature that focuses on this effect. To generate such data, two identical, 101 mm dia., 57 mm long bearings—one fabricated from steel and one from bronze—have been tested in a precision journal bearing test rig. Comparisons between shaft displacement data for steady loading of the two bearings show that the deformations are important to consider.Presented at the 48th Annual Meeting in Calgary, Alberta, Canada May 17-20, 1993

ISSN:1040-2004    

DOI:10.1080/10402009408983367

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Externally pressurized gas (EPC) bearing pads with convergent conical shapes can provide high load capacity and high stiffness. Research has revealed that if the suitable combination of gap difference and working gap height is chosen, the optimized diameter ratios for stiffness and load capacity are close to the same value, about 0.8 to 0.9, or the ratio of the diameter of the conical gap-shaped part over the pad diameter. The optimized diameter ratio is independent of the supply pressure, the pad diameter and the number of conical parts. Conversely, the stability of the bearings is controlled by the combination of the diameter ratio and the gap difference. From the analysis of the stability criteria and the optimized diameter ratio, the concept of the tri-conical gap-shaped EPG bearing pads was proposed. Numerical and experimental investigation shows that under the same stable conditions, tri-conical gap-shaped pads provide higher stiffness and higher load capacity than simple conical or parallel gap-shaped pads.

ISSN:1040-2004    

DOI:10.1080/10402009408983368

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The purpose of this research was to investigate the pressure and temperature effects of graphite powder lubricant when added to a Newtonian carrier fluid and applied in a rotating hydrostatic step bearing. Temperature and pressure profiles were determined both analytically and experimentally. The rheological behavior of the non-Newtonian lubricant was modeled using a power law model previously shown to approximate experimental data for this fluid. Ethylene glycol was used as the Newtonian lubricant, providing a check on the test apparatus and a base line for comparison with the non-Newtonian graphite slurry.

ISSN:1040-2004    

DOI:10.1080/10402009408983369

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The well-known problem of stiction in a magnetic disk drive largely depends on the forces induced by the presence of a thin liquid film. It is commonly recognized that both adhesive and viscous effects contribute to the magnitude of the stiction force, but is is not known what relative roles the two effects have in a lubricated contact. In the present work, the nature of adhesive and viscous effects is investigated for the slider/disk interface under conditions of constant-speed sliding.

ISSN:1040-2004    

DOI:10.1080/10402009408983370

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The mechanics of the deformations and the destruction of the asperities of rough surfaces has been considered, taking into account the mutual influence of the elastic constants of the materials participating in the friction couple.

ISSN:1040-2004    

DOI:10.1080/10402009408983371

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

For a short bearing or face seal, the temperature is determined by a steady Couette flow component and a zero-average perturbation, or waviness. In terms of these component flows, convection along the film and conduction into the surfaces is derived, and conditions are determined under which convection significantly influences the circumferential distribution of heat flux into the solid surfaces. For a stationary sinusoidal wave on a bearing surface, the phase relationship between this displacement perturbation and the wall heat input is found. The result is primarily of interest in systems where frictional heating may excite the thermoelastic growth of surface waviness, and where weak perturbations on heating may excite thermoelastic instability.

ISSN:1040-2004    

DOI:10.1080/10402009408983372

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor