摘要:

Fluorides of the alkali metals and the alkaline earth metals have an interesting combination of properties that make them promising candidates as solid lubricant materials for use at high temperatures and in corrosive environments. They are chemically inert in strong oxidizing or reducing environments; they are relatively soft and nonabrasive; and some of them, such as CaF2, have planes of perfect cleavage in their crystal structure suggesting low-shear strength and good friction properties. Thin, fused fluoride coatings (0.001 inch) were applied to nickel-chromium alloys by spraying water slurries of the fluorides on the bearing surface, drying it, then firing it in a hydrogen atmosphere. Coatings of CaF2-LiF mixtures and of CaF2-BaF2mixtures were effective as solid lubricants in hydrogen to 1500 F and in air to 1200 F. The CaF2-BaF2coatings were effective solid lubricants in liquid sodium at 1000 F and a sliding velocity of 2000 ft/min.Contributed by the ASLE Technical Committee on Solid Lubricants and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Detroit, Michigan, May 1965.

ISSN:0569-8197    

DOI:10.1080/05698196508972103

出版商:Taylor & Francis Group    

年代:1965

数据来源: Taylor

摘要:

Extensions to the theory for the continuous film journal bearing are presented. These analyses are used in conjunction with the results of other analyses to provide design data orf the complete operating range of a full circular journal bearing.Contributed by the ASLE Technical Committee on Bearings and Bearing Lubrication and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Detroit, Michigan, May, 1965.

ISSN:0569-8197    

DOI:10.1080/05698196508972104

出版商:Taylor & Francis Group    

年代:1965

数据来源: Taylor

摘要:

The results of an experimental investigation of an externally pressurized, porous wall, nonrotating journal bearing that used air as a lubricant are compared with a previously published analysis and found to be in good general agreement, provided the eject of surface roughness is included in the determination of the clearance.Contributed by the ASLE Technical Committee on Bearings and Bearing Lubrication and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Detroit, Michigan, May, 1965.

ISSN:0569-8197    

DOI:10.1080/05698196508972105

出版商:Taylor & Francis Group    

年代:1965

数据来源: Taylor

摘要:

Data are reported for two rotors (1.44 and 5.88 pounds) supported by externally pressurized gas bearings. Comparative plots show that the effective spring rate for synchronous whirl (a function of pressure) also serves to account for the shaft displacement under gravity load and under low-frequency impact loading. Exceptions are noted at the half-speed whirl threshold and at low speed and low pressure. Some explanation is offered for these discrepancies, as well as for observed displacements somewhat in excess of that predicted on the basis of the linear spring, under impact.Contributed by the ASLE Technical Committee on Bearings and Bearing Lubrication and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Detroit, Michigan, May, 1965.

ISSN:0569-8197    

DOI:10.1080/05698196508972106

出版商:Taylor & Francis Group    

年代:1965

数据来源: Taylor

摘要:

The lubrication requirements of the Mercury Rankine Silent Compact Auxiliary Power (SCAP) system are presented and the types of journal and thrust bearings suitable for the application are reviewed. Mercury lubricated hybrid bearings have been successfully developed for the turboalternator that are capable of a dry start, and operation in a vertical orientation and at elevated temperatures up to 400 F. Performance characteristics of these bearings operating at mean Reynolds numbers of approximately 4,500 are presented.Contributed by the ASLE Technical Committee on Bearings and Bearing Lubrication and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Detroit, Michigan, May, 1965.

ISSN:0569-8197    

DOI:10.1080/05698196508972107

出版商:Taylor & Francis Group    

年代:1965

数据来源: Taylor

摘要:

The mixing length theory, used previously for the determination of the velocity profiles and pressure distributions in turbulent films is now employed in order to determine the friction stresses To, Thon the two lubricated surfaces and their dependence on the Reynolds number and on the pressure distribution. Thus, it results that the curves τo(Bxτ and –τh(Bx) are antisymmetric and that the derivatives τo/τBx, τh/τBxat Bx= 0 have constant values, independent of the Reynolds number. These results allow the determination of simple analytical formulas for the friction stresses τo.has functions of the Reynolds number and of the parameter Bx, by using a linearization procedure, valid for small and moderate variations of the film thickness.

ISSN:0569-8197    

DOI:10.1080/05698196508972108

出版商:Taylor & Francis Group    

年代:1965

数据来源: Taylor

摘要:

This paper describes experimental measurements of the conditions occurring in the conjunctive region of two lubricated cylindrical disks which roll or roll and slide on their peripheral surfaces under load. The results of these measurements are compared with those of the recent elastohydrodynamic theory, including thermal effects. The measured quantities include lubricant film pressure distribution, surface temperature distribution, and the shape and thickness of the lubricant film, all measured in the direction of rolling. The results suggest several improvements and modifications of the thermal elastohydrodynamic theory including an improved analysis of the inlet region and modification of the lubricant rheological model to include effects of shear or time dependence.Contributed by the ASLE Technical Committee on Bearings and Bearing Lubrication and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Detroit, Michigan, May, 1965.

ISSN:0569-8197    

DOI:10.1080/05698196508972109

出版商:Taylor & Francis Group    

年代:1965

数据来源: Taylor

摘要:

In this paper, a recent solution on the thermal-elastohydrodynamic lubrication of rolling and sliding cylinders is extended to consider a more rigorous analysis of temperature by using a two-dimensional finite difference method. The effect of the local pressure-temperature dependent viscosity, the compressibility effect of the lubricant and the heat from compression of the lubricant are considered in the solution of the Reynolds and the energy equations.

ISSN:0569-8197    

DOI:10.1080/05698196508972110

出版商:Taylor & Francis Group    

年代:1965

数据来源: Taylor

摘要:

Lubricant film thickness in the partial elastohydrodynamic range was measured as a function of rolling speed in a rolling 4-ball configuration, for four mineral oils, two esters and a polyphenylether covering a viscosity range of 8–360 cs. Film thickness is shown to vary with speed as a power function. At the point where a full elastohydrodynamic film is formed, the product of viscosity and speed is constant for most lubricants.

ISSN:0569-8197    

DOI:10.1080/05698196508972111

出版商:Taylor & Francis Group    

年代:1965

数据来源: Taylor

摘要:

The author carried out an experimental investigation on the motion of a ball in an angular-contact ball bearing under thrust load by measuring change in magnetic flux induced by a magnetized ball. The observed data of the angular velocity of the ball and that of the cage were adequate for analyzing the kinematical condition in the bearing. It is noted that the ratios of the angular velocities of the rolling elements are closely related to the parameter zFe/Pa, where z, Feand Padenote the number of balls in the bearing, the centrifugal force acting on a ball and the magnitude of thrust load, respectively. In the range zFe/Pa> 0.1, the deviation of the observed data from the values theoretically predicted based upon a simple assumption neglecting the gyroscopic moment is remarkable. In order to explain the experimental results reasonably, it is necessary to consider the gyroscopic moment along with the effect of the centrifugal force.Contributed to the American Society of Lubrication Engineers by the author.

ISSN:0569-8197    

DOI:10.1080/05698196508972112

出版商:Taylor & Francis Group    

年代:1965

数据来源: Taylor