摘要:

This paper introduces a novel approach for low flying sliders. The authors propose a slider with a programmable air bearing that permits it to be flown high or low on demand. This is achieved by changing the shape of the slider body with the use of piezoelectric materials. The design of the slider is presented along with simulation results that indicate a flying height change from 186 to 53 nm with a 80 volt excitation. Experimental data shows a slider changing height in 500 μsec under very stable conditions. The advantages of electrically controlled flying heights are discussed.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:10.1080/10402009108982070

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Steady-state compressible isothermal lubrication problems with slip-flow conditions are formulated by the p-version hierarchical finite element method (p-FEM) together with the Newton-Raphson iterative procedure. Numerical solutions for gas lubricated bearings of finite and infinite width are presented. Even for high bearing number situations and coarse meshes, the current formulation yields stable, accurate and rapidly convergent results.

ISSN:1040-2004    

DOI:10.1080/10402009108982071

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Slider bearing gaps are often measured using the white light interference spectrum from the narrow gap between the slider and a spinning glass disk. Using that same interference data, one can also estimate the amplitude of the first oscillatory mode of the slider. This paper illustrates this method with simulations and with actual interference data. This approach uses conventional white light interferometry data and requires no additional hardware or modification of equipment. It can be extended to estimate amplitudes of higher frequency modes.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:10.1080/10402009108982072

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

An approximate model is proposed for simulating head-to-tape spacing in helical scan video tape recording. The particular issues focused on in the paper are the effect of the variability of scanner to tape spacing along the helix as well as the effect of the head contour. From scanner-to-tape air film values, the paper deduces the relation between head and tape at the recording track and predicts the RF envelope shape. The important goal accomplished in the paper is to provide an explanation and a model for the phenomenon of development of taper in the RF envelope.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:10.1080/10402009108982073

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

When contacting solids slide, work is done against friction. Almost all the frictional work appears as heat, generated at or very close to, the surface at which the two solids meet. The local increase in temperature influences both the friction and the rate of wear. In this paper, frictional heating is analyzed using a particularly simple framework. The analysis provides for a wide range of geometries for the two contacting solids, which may differ in their thermal and mechanical properties, and may not be in perfect contact with the heat-sinks to which they are attached. The results are presented as temperature maps which show the surface temperature of a sliding couple over a wide range of load and sliding velocity.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:10.1080/10402009108982074

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

A numerical solution to the problem of thermal compressible elastohydrodynamic lubrication of rolling/sliding contacts has been tested over a wide range of operating parameters consisting of dimensionless load, speed, slip, and material parameters. A least squares exponential curve fit was used to develop simple formulas for the amplitude and location of the pressure spike, the minimum film thickness, and the maximum lubricant temperature as a function of the operating parameters. These equations can be used to evaluate parameters affecting the performance of rolling/sliding heavily loaded lubricated contacts.Presented at the 45th Annual Meeting in Denver, Colorado May 7–10, 1990

ISSN:1040-2004    

DOI:10.1080/10402009108982075

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

A flexible elastic disk is rotating at constant angular velocity in close proximity to a stationary baseplate. Such a configuration can be used to stabilize the flexible medium in magnetic and/or optical recording applications. The influence of coupling between in-plane displacements and transverse deflections is investigated. The effects of bending stiffness and of the air flow between the disk and the backplate are also included. Solutions of the nonlinear differential equations are obtained using finite difference approximations and an iterative approach. The results for this reference configuration are the transverse deflections, the air film pressure, and the displacement-induced membrane state. The significance of coupling is assessed. The governing equations of the disk and of the air film are then linearized about the reference configuration and a measure of the disk stiffness is determined. Comparisons are made with another model which uses an elastic foundation parameter in order to represent the air film.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:10.1080/10402009108982076

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

An expression is suggested for correlating viscosity and kinematic viscosity data over a wide range of pressure and temperature. This expression is obtained by expanding the natural logarithm of viscosity in a series about ambient pressure and temperature. This series expansion is truncated to obtain a relatively simple relation that contains several useful empiricisms as special cases. Coefficients in this expansion are conveniently determined using a regression analysis. The proposed relation describes ASME data for several oils to within a 3 percent average deviation for pressures to 350 MPa (50 ksi) and temperatures to 373 K (100°C). The average deviation is less than 15 percent for pressures to 1.0 GPa (150 ksi) and temperatures to 491.5 K (218°C). In both cases, the agreement is typically much better than those predicted by other correlations over the same range of pressure and temperature.

ISSN:1040-2004    

DOI:10.1080/10402009108982077

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Knowledge of the taper angle of the lubricating film of a rotary mechanical seal is fundamental to understanding seal performance. Whilst the literature contains numerous reports of mechanical seal distortion analysis, these usually deal with specific seal designs. This paper addresses the analysis procedures more generally, giving a detailed discussion of factors affecting prediction of seal ring distortions, especially heat partitioning, locating reaction diameters and estimation of heat transfer coefficients. The “face locking” concept is discussed. Use of influence coefficients is discussed and an extension of this concept for distributed interfacial pressure is presented. Finally a typical analysis sequence is outlined.Presented at the 45th Annual Meeting In Denver, Colorado May 7–10, 1990

ISSN:1040-2004    

DOI:10.1080/10402009108982078

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The sliding system used with particulate rigid disks, involving a ceramic head sliding against a disk coated with iron oxide particles in a resin iv unusual in a number of ways. Perhaps the most striking is that, in use, there is for a long time no measurable wear, but once damage is initiated failure is rapid. To investigate this type of wear, numerous pin-on-disk sliding tests have been carried out. Analysis of the wear results suggests that in the authors' tests, the failure is caused by adhesive rather than abrasive or fatigue wear; however, it is not easy to judge whether failure is due to the wearing away of the alumina particles in the magnetic coating, or else to a polymer coating adhering to the pin surface.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:10.1080/10402009108982079

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor