摘要:

The nature of the boundary lubricating film and its formation mechanism has been the subject of research in the last several decades. This study describes the development of a novel analytical technique designed specifically for the analysis of small amounts of lubricating film using an integrated size exclusion chromatography-refractive index-ultraviolet-graphite furnace atomic absorption (SECRI-UV-GFAA) system.

ISSN:1040-2004    

DOI:10.1080/10402008908981909

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This paper describes the results of an investigation into the behavior of the flow of a laminar, incompressible Newtonian fluid contained between two parallel, flat circular plates for fast flow, Reo⩾1. Both unsteady and convective fluid inertia terms are considered in conjunction with system extend effects. The equation of motion of the system is coupled with the equation for the film force and solved numerically until the solution converges. The results show the generation of a steady-state force due to the inclusion of the fluid inertia forces and the forces associated with the external system constants. The extent to which lubricant properties, operating variables, and system constants influence the steady-state response of the bearing is analyzed. In addition, the effect of the bearing support flexibility on the prediction of the critical speed in relation to the steady-state operation of the system is assessed.Presented as a Society of Tribologists and Lubrication Engineers paper at the ASME/STLE Tribology Conference in Baltimore, Maryland, October 16–19, 1988

ISSN:1040-2004    

DOI:10.1080/10402008908981910

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Experimental investigation of lubricated rolling and sliding contact for three types of Si3N4against nodular cast iron reveal that additives to the Si3N4and processing methods affect wear rates and wear modes. The friction coefficient is governed by the contact type rather than by the material type. In rolling contact tests, grain pullout of Si3N4caused a higher wear rate than submicron chipping. In sliding tests, tungsten carbide particles added in the Si3N4matrix inhibit the wear by 50 percent. Schematic drawings of these wear processes are presented representing the wear modes in a stepwise manner.

ISSN:1040-2004    

DOI:10.1080/10402008908981911

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Stability criteria for gas-lubricated sliders for magnetic disk drives are analyzed using Hori's method. Some relations between flotational stability and float factors are discussed.

ISSN:1040-2004    

DOI:10.1080/10402008908981912

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

It was already stated in the previous paper that the estimation of friction losses prior to the design stage was vital for automobile engines. In that paper, the theoretical analysis on piston friction losses was developed, and equations using the analytical results and motoring test results were introduced for the calculation of instantaneous and mean values of the friction losses corresponding to those of actual engine tests.

ISSN:1040-2004    

DOI:10.1080/10402008908981913

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This paper presents an analytic solution for the flow of a laminar incompressible Newtonian fluid between two parallel circular plates undergoing oscillatory motion. The solution uses an iterative approximation technique and includes both convective and unsteady fluid inertia terms. The extent to which these terms influence the pressure and load carrying capacity for various flow parameters is analyzed. The results show a significant deviation from the inertialess (viscous) solution at low excursion ratio, e, and moderate modified Reynolds number, Reo. For a purely harmonic (sinusoidal) motion of the plates, a steady-state force is generated in addition to the dynamic transient force. This is due to the inclusion of the inertia terms and is shown to be a function of the excursion ratio, e, and another dimensionless parameter, the squeeze velocity number, N.

ISSN:1040-2004    

DOI:10.1080/10402008908981914

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The effect of inertia and flow development on bearing behavior has been investigated numerically and experimentally. The full Navier-Stokes equations are solved for a slider-type bearing and compared to experimental results. The computational domain covers the far upstream region as well as the bearing gap region to evaluate the inlet condition correctly. Experiments have been conducted with a simulated partial-arc bearing. The measured far upstream velocity profile is adopted as a boundary condition in numerical analysis instead of assuming a uniform bearing inlet velocity profile which has been used by previous authors. The resulting velocity profile across the inlet gap is neither uniform nor entirely viscous in nature. Numerical results agree well with experiment in a range of he modified Reynolds number 3 to 30. A significant so called “rum pressure” effect is found and this can be portrayed through a loss coefficient.Presented as a Society of Tribologists and Lubrication Engineers paper at the ASME/STLE Tribology Conference in Baltimore, Maryland, October 16–19, 1988

ISSN:1040-2004    

DOI:10.1080/10402008908981915

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A mechanical seal with deep hydropad slots distributed around the circumference of one face is analyzed theorelically. The computational procedure is bared on an analytical model in which the hydropads induce the seal face to deform into à circumferential wave pattern, leading to hydrodynamic pressure generation. The procedure allows computation of film thicknesses, pressure profiles and leakage flow rates. The latter agree well with experimental measurements.Presented as a Society of Tribologists and Lubrication Engineers paper at the ASME/STLE Tribology Conference in Baltimore, Maryland, October 16–19, 1988

ISSN:1040-2004    

DOI:10.1080/10402008908981916

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Velocity accommodation across rubbing surfaces lubricated with thick films is well understood and can be determined from fluid dynamics theory. The situation is not the same in “dry” friction as the question is not usually formulated in the same terms.

ISSN:1040-2004    

DOI:10.1080/10402008908981917

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Fractal geometry, in which infinite numbers of fractional dimensions are permitted in contradistinction to the three integer dimensions in Euclidean geometry, has been applied to the study of surface roughness. A tentative conclusion is that fractal geometry offers yet another vehicle for the physical chemist to meet the mechanical engineer on solving problems in the boundary lubrication regime of tribology. Of course, fractals have been applied to the study of turbulence which is within the fluid film lubrication regime. Other potential applications might include all processes in tribology which are stochastic in nature.Presented as a Society of Tribologists and Lubrication Engineers paper at the ASME/STLE Tribology Conference in Baltimore, Maryland, October 16–19, 1988

ISSN:1040-2004    

DOI:10.1080/10402008908981918

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor