摘要:

In swing pad bearing, the pad is supported by curved layers of alternate laminates of elastomer and metal. The hydrodynamic wedge is formed by the swing of the pad about the center of curvature of the laminate as a result of fluid friction force. This paper extends the previous analysis (Dawson, (1)) by including the stiffnesses of the laminates under the pad in the equilibrium analysis of the pad and metal shims. The deformation of the curved elastomer layers is assumed to consist of compression, bending and shearing of the curved layer. The latter two contribute to the swing of pad surface. Each of the deformation mode has been formulated and the deflections have been calculated in the form of Fourier series. An example is given using water as lubricant.Presented at the 43rd Annual Meeting in Cleveland, Ohio May 9–12, 1988

ISSN:1040-2004    

DOI:10.1080/10402008908981869

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The friction, wear, endurance life, and surface morphology of rubbed (burnished) fluorinated graphite and fluorinated coke materials were studied. Two different coke powders, a graphitic carbon powder, and a graphite powder were fluorinated and then tribologically investigated. In addition, one of the coke powders was reduced in size before fluorinating to evaluate the effect of a finer particle size on the tribological properties. For comparison, graphite and coke powders which were not fluorinated were also tribologically evaluated. Elemental analysis by emission spectroscopy was performed on each sample to determine the impurity content and X-ray diffraction analysis was performed to determine the crystallinity. Coke was found to have very little lubricating ability, but fluorinated coke did possess good lubricating properties. However, the fluorinated graphite and fluorinated graphitic carbon (which gave equivalent results) gave superior results to those obtained with the fluorinated cokes. No tribological benefit was found for using small versus a larger particle size of coke, at least when evaluated as a rubbed film.Presented at the 43rd Annual Meeting in Cleveland, Ohio May 9–12, 1988

ISSN:1040-2004    

DOI:10.1080/10402008908981870

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Interferometry was used to measure in situ the thickness profiles of evaporating thin films as a function of heat flux for low concentration polystyrenel/cyclohexane solutions. Evaporative heat flow rates per unit width of contact line were calculated based on polynomial fits of interference data, combined with a fluid flow model. Temperature profiles obtained from thermocouple measurements were employed in evaluating macroscopic interline region heat sink capacities using a one-dimensional heat conduction model. Reasonable agreement between evaporative heat fluxes derived from both methods was established. Pure solvent integral heat fluxes were not significantly altered through polymer addition. Fluid flow toward the triple interline to replace that which evaporated resulted in an apparent non-equilibrium phase separation of concentrated polymer solution from the bulk phase; the separation increased with increasing polymer molecular weight and concentration. A substantial rise in the reflectivity beyond the first interference fringe indicated the possible deposit of an ultra-thin polymer or polymer solution film.Presented at the 42nd Annual Meeting in Anahelm, California May 11–14, 1987

ISSN:1040-2004    

DOI:10.1080/10402008908981871

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The effect of molecular structural variations in silahydrocarbons on thermal stability was investigated. The silahydrocarbons chosen for these studies contain a silicon atom and three n-octyl groups and another substituent group which provides the structural variation. The structural variations in the C5substituent group are branching, the position of the branching, the presence of double bond, and the variation in the position of the double bond. The thermal stability of the above compounds was determined, and the extent of degradation was measured using gas chromatography, viscosity change, and coupled gas chromatographic-mass spectroscopic analysis. Interesting trends were found and the rationale for these trends is presented.Presented at the 43rd Annual Meeting in Cleveland, Ohio May 9–12, 1988

ISSN:1040-2004    

DOI:10.1080/10402008908981872

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A two-dimensional linear elastic contact problem, relevant to fretting fatigue analysis, is formulated and solved numerically. It is assumed that the contact region contains a centrally located stick zone between two regions of micro-slip in which the Amontons-Coulomb law of sliding friction is assumed to apply. The solution yields the contact stress distributions, size and location of the stick zone, relative displacements in the regions of micro-slip and the energy dissipation per cycle of tangential loading. Results for energy dissipation per cycle, and the steady state location of the stick zone versus tangential loading are given for three different values of an interaction parameter.Presented at the 43rd Annual Meeting in Cleveland, Ohio May 9–12, 1988

ISSN:1040-2004    

DOI:10.1080/10402008908981873

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A study of the performance parameters for a journal bearing of finite length lubricated with micropolar fluids is undertaken. Results indicate that a significantly higher load carrying capacity than Newtonian fluids may result depending on the size of material characteristic length and the coupling number. It is also shown that although the frictional force associated with micropolar fluid is in general higher than that of a Newtonian fluid, the friction coefficient of micropolar fluids tends to be lower than that of the Newtonian.Presented at the 43rd Annual Meeting in Cleveland, Ohio May 9–12, 1988

ISSN:1040-2004    

DOI:10.1080/10402008908981874

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

An experimental investigation was conducted to study the simultaneous effects of Non-newtonian lubricant behavior and thermal dissipation during hydrodynamic lubrication of a journal bearing. The results show that thermal effect is an important factor not to be neglected in any theoretical analysis of hydrodynamic lubrication. When we compare a non-Newtonian oil (2.25 percent PIB L80 in Vitrea 32) and a Newtonian oil of the same zero shear rate viscosity (Vitrea 320), they show the same load capacity (or Sommerfeld number) up to a relative eccentricity ε = 0.5. Beyond this point, the Newtonian oil exhibits a higher Sommerfeld number. Due to viscous dissipation, the normal stresses exhibited by the non-Newtonian oil cannot compensate for the loss of viscosity by shear thinning.

ISSN:1040-2004    

DOI:10.1080/10402008908981875

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A ship's main drive shaft axial vibration at propeller blade rate may be transmitted to the hull. A method for reducing these vibrations is investigated in this paper. A proposed design consists of an auxiliary shaft magnetic thrust bearing added in parallel to the shaft fluid film (mechanical) thrust bearing. The blade passing oscillatory load supported by the auxiliary magnetic bearing reduces the overall magnitude of the oscillatory thrust. The magnet current is controlled through an electronic feedback circuit.

ISSN:1040-2004    

DOI:10.1080/10402008908981876

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This is a companion paper to “ACTIVE MAGNETIC CONTROL OF OSCILLATORY AXIAL SHAFT VIBRATIONS IN SHIP SHAFT TRANSMISSION SYSTEMS—Part 1: System Natural Frequencies and Laboratory Scale Model.” Details of the modeling process were presented in that paper. In this work, the control analysis and some initial response results of the experimental system, which consists of a simulated fluid film thrust bearing coupled with a magnetic auxiliary thrust bearing, are presented. A 30 percent reduction of transmitted force was obtained. The extremely high sensitivities predicted for the system suggested that such a force reduction would be highly unlikely. It is felt that an order of magnitude of transmitted force reduction can be obtained with proper modifications to the controls and to the physical system.Presented at the 43rd Annual Meeting in Cleveland, Ohio May 9–12, 1988

ISSN:1040-2004    

DOI:10.1080/10402008908981877

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Theoretical analysis of dynamic tracking and leakage characteristics of a self-centering, hydrostatic, stepped gas seal is presented.

ISSN:1040-2004    

DOI:10.1080/10402008908981878

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor