摘要:

This paper describes the experimental pressure and temperature results obtained when rotating a shaft in an eccentric lucite casing at velocities raging from 209 to 628 rad/s (2000 to 6000 rpm). The results are presented in terms of three-dimensional plots and contour maps. Photographic evidence is presented to illustrate how the downstream and upstream regions of the cavity develop and evolve into the well-known finger patterns. A comparison between pressure and temperature profiles in air-saturated oil and carbon dioxide-saturated oil is presented; the origin and nature of the gases contained in the cavity are discussed. Three analytical models (Swift-Stieber, separation, Floberg) predicting the formation of the cavitation zone are presented and evaluated in light of the experimental results. A motion-picture supplement depicting these results is available upon request.Presented as an American Society of Lubrication Engineers paper at the ASME/ASLE Lubrication Conference in Washington, D.C., October 5–7, 1982

ISSN:0569-8197    

DOI:10.1080/05698198408981539

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The relation between the theoretical tensile and the shear strengths and the friction properties of metals in contact with diamond, boron nitride, silicon carbide, manganese-zinc ferrite, and the metals themselves in vacuum was investigated. The relationship between the actual shear strength and the friction properties of the metal was also investigated. An estimate of the theoretical uniaxial tensile strength was obtained in terms of the equilibrium surface energy, interplanar spacing of the planes perpendicular to the tensile axis, and the Young's modulus of elasticity. An estimate of the theoretical shear strength for metals was obtained from the shear modulus, the repeat distance of atoms in the direction of shear of the metal, and the interplanar spacing of the shear planes. The coefficient of friction for metals was found to be related to the theoretical tensile, theoretical shear, and actual shear strengths of metals. The higher the strength, of the metal, the lower the coefficient of friction.Presented as an American Society of Lubrication Engineers paper at the ASME/ASLE Lubrication Conference in Washington, D.C., October 5–7, 1982

ISSN:0569-8197    

DOI:10.1080/05698198408981540

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The response of atomic absorption spectrophotometry (AAS) to iron-based wear debris in gas-turbine lubricating oils was measured. It was discovered that the absolute content of wear metal in oil samples was not attainable because of two factors. First, the engine filter system removed substantial amount of debris and secondly, under normal working conditions, the AAS was completely insensitive to iron metal particles and only partially sensitive to iron oxide. Engine health monitoring based on selecting maximum wear debris cutoff values can be misleading if an AAS is used. AAS results however, can be of practical value to show wear metal accumulation trends.

ISSN:0569-8197    

DOI:10.1080/05698198408981541

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

A review of friction theories relevant to the interaction between magnetic-recording-device components (hard, inelastic materials) and viscoelastic, polymeric materials used in the manufacture of flexible, magnetic tape is presented. Tabor's classical theory of adhesion with appropriate deformation and shear-strain rates, as well as Hegmon's theory of hysteresis friction, adequately describes the frictional behavior. Other sources of adhesional friction are stiction, meniscus, and microcapillary evacuation.

ISSN:0569-8197    

DOI:10.1080/05698198408981542

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

This study was conducted to determine the rates of mineral oil oxidation and organometallic compound formation at temperatures approaching those existing in concentrated contacts. The thin-film microreactor was used so that diffusional effects could be analyzed and quantified. This allowed the calculation of rate coefficients for the oxidation reaction. These rate coefficients were then used in a kinetic model of the four-ball wear tester to predict film thickness in concentrated contacts.Presented at the 38th Annual Meeting in Houston, Texas, April 24–28, 1983

ISSN:0569-8197    

DOI:10.1080/05698198408981543

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

This paper presents a new concept for a self-acting, rotating-shaft gas seal. One of the seal faces is elastically distorted to provide a converging tilt and wavy shape on the face. The tilt enhances hydrostatic load support while the waviness enhances hydrodynamic load support. By moving the wave slowly elastically, this unique shape is preserved in spite of any wear. Leakage is essentially blocked by a continuous sealing dam around the seal. Advantages claimed are low leakage and tolerance to liquid contamination.

ISSN:0569-8197    

DOI:10.1080/05698198408981544

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

An experimental program was conducted to measure film temperature in all the pads of a 127-mm (5-inch) diameter five-shoe tilting-pad journal bearing, load-between-pad configuration. Film temperature measurements were taken both in the circumferential and axial directions of the pads at different speeds, loads, and flows. The tests were conducted in speeds ranging from 3000 to 13 000 rpm, unit bearing load range of 34.5 × 104to 172.4 × 104N/m2(50 to 250 psi) and at flows of 0.177, 0.252 and 0.379 L/s (2.8, 4.0, and 6.0 gpm). The actual power losses have also been compared to the theoretical power losses.

ISSN:0569-8197    

DOI:10.1080/05698198408981545

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Previous work has shown that reaction of zinc di-n-octyldithiophosphate with peroxy radicals in laboratory experiments led to products which were ineffective as antiwear agents. These products have now been identified and a material balance obtained by the application of several analytical techniques. The principal reaction product was the disulfide species tetra-n-octylthioperoxydiphosphate. This compound was synthesized, tested, and found to be less effective than zinc di-n-octyldithiophosphate as an antiwear agent.Presented at the 38th Annual Meeting in Houston, Texas, April 24–28, 1983

ISSN:0569-8197    

DOI:10.1080/05698198408981546

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Testing of small high-speed floating-ring bearings, typical of those used in automotive turbochargers, revealed a discrepancy between ring speed measurements and ring speed prediction using isothermal bearing analysis. As bearing stability, energy loss, and load capacity are dependent on ring speed, an experimental program was undertaken to determine the effects of various bearing parameters on ring speed. The program results show that none of the 16 bearing parameters investigated increased the bearing ring speeds to those values predicted by the isothermal bearing analysis. In parallel with the experimental program, a thermal analysis was developed in which the effects of lubricant and bearing temperature on the ring speed of a floating-ring bearing way investigated. The ring speed predictions from this thermal floating-ring bearing model agree with the measured values except at the lowest and highest speeds tested. Therefore, for the type of floating-ring bearing design described in this paper, it is concluded that thermal heating can contribute significantly to ring-speed reduction.Presented at the 38th Annual Meeting in Houston, Texas, April 24–28, 1983

ISSN:0569-8197    

DOI:10.1080/05698198408981547

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The endurance lives of rf sputtered MoS2lubricant films are severely degraded by exposure to high humidity environments prior to wear testing. Surface chemical and electron microscopic analyses show that the degraded films are oxidized to form MoO3and that the oxidation rate is a function of the orientation of the crystallites composing the films before any run-in or burnishing activity. If the crystallites are arranged with their basal planes parallel to the substrate surface, the films have lower reactivity (good stability) and longer endurance lives than film with randomly oriented crystallites. The results of surface analyses and wear tests are presented to support these observations.

ISSN:0569-8197    

DOI:10.1080/05698198408981548

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor