摘要:

In general, slew bearings are less firmly supported by their mounting structures than small bearings. Hence, the load distribution around the bearing may be vastly different than that predicted by classic bearing formulas. The finite element method has been employed to determine load distribution in a three-row roller slew bearing mounted between two flexible, ring shaped supporting structures composed of beam elements. A special bar element modeling the system of two opposite rollers in contact with its raceways has been elaborated. The influence of the nonlinear force displacement characteristics of each of the rollers, as well as the influence of gaps between the rollers and its raceways have been taken into account. The nonlinear contact problem has been solved utilizing the Newton-Raphson method with continually updated stiffness matrix due to both element nonlinearity and contact status. The effect of a number of design parameters on the load distribution has been investigated.

ISSN:1040-2004    

DOI:10.1080/10402009408983356

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A computer program for analyzing the lubrication state of gears was developed, and the lubrication states of two lubricants on two test rigs were investigated. The calculation and tests correlated well. Finally, satisfactory results were achieved when the program was used on an industrial field.Presented at the 48th Annual Meeting in Calgary, Alberta, Canada May 17-20, 1993

ISSN:1040-2004    

DOI:10.1080/10402009408983357

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A ringless high pressure moving seal has been developed which can reach pressures as high as 1200 MPa. A unique feature of the seal is the elastic action of its plunger. This action results in full oil film operation that enhances volumetric efficiency while reducing leakage. Analysis and results of the pressure examination are presented. It is shown that the seal operates with high volumetric efficiency, very low friction and no wear.Presented at the 49th Annual Meeting in Pittsburgh, Pennsylvania May 1-5, 1994

ISSN:1040-2004    

DOI:10.1080/10402009408983358

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A general approach for incorporating heat transfer and elastic deformation effects into a tilting-pad journal bearing simulation model is presented. A global analysis method is used, which includes variable viscosity and heat transfer effects in the fluid film, elastic deformation and heat conduction effects in the pads, and elastic deformation effect in the pivots. The two-dimensional variable viscosity. Reynolds equation produces pressure distributions in the axial and circumferential directions. The energy equation is two-dimensional, assuming that the temperature variation in the axial direction is negligible. The elasticity and heat conduction models are also two-dimensional, being in the midline cross-section of the bearing, including the circumferential and cross-film directions. An upwind technique is used in the finite element formulation of the energy equation to remove numerical instability due to the convective term. Simulation results are compared with the test and predicted values of previous researchers.Presented at the 48th Annual Meeting in Calgary, Alberta, Canada May 17-20, 1993

ISSN:1040-2004    

DOI:10.1080/10402009408983359

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

In the modeling and analysis of rotordynamic systems with journal bearings, the stiffness and damping parameters are usually obtained from the Reynolds equation of hydrodynamic lubrication. The Reynolds equation is derived from the continuity and momentum equations with several assumptions; the principal one among them being that the inertia terms are negligible since the lubricant flow is viscosity-dominated. Some previous work has shown, however, that the effect of fluid inertia on the static and dynamic properties of a bearing is not negligible in many circumstances.

ISSN:1040-2004    

DOI:10.1080/10402009408983360

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Computer-aided design of bearing systems is finding its way into many industrial sectors requiring high reliability and trouble-free performance from rotor/bearing systems. This trend will accelerate as more bearing analysis codes are ported to the personal computer and incorporate user-friendly interfaces. This paper describes and explains the theoretical basis for bearing load rating and life estimating as reflected in such programs. The calculation of individual bearing and system B-10 Fatigue Life and their correlation to the ISO International Standard 281 for dynamic load ratings and rating life is presented. Showing the continuity from the standard methods to the more fundamental computer analysis of bearing systems will allow for a smooth transition from one to the other.Presented at the 47th Annual Meeting in Philadelphia, Pennsylvania May 4-7, 1992

ISSN:1040-2004    

DOI:10.1080/10402009408983361

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

An attempt is made to solve the Reynolds equation as a nonlinear equation for unknown film thickness ratio and tilt parameters. The film thickness is considered to be varying in circumferential and radial directions due to the roll and pitch motion of the pad, about the center of pressure obtained after the thrust pad is manufactured/assembled. The pressure profile obtained when the pad is in equilibrium is used to analyze the distortion of the spring-supported thrust pad. Such a type of analysis is necessary to predict the actual performance of a thrust pad bearing, since the thrust pad is not likely to operate with the initially chosen inlet/outlet film thickness ratio as a result of distortion. Hence, the center of pressure decided at the design stage will change with the operating conditions.

ISSN:1040-2004    

DOI:10.1080/10402009408983362

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This paper examines the influence of electrochemical potentials on the friction and wear of iron/iron and iron oxide/alumina oxide rubbing contacts, lubricated with aqueous fluids.

ISSN:1040-2004    

DOI:10.1080/10402009408983363

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The governing equations developed in (1), where a perturbation method is applied in the equation of motion and the energy equation is linearized, are used to study journal bearings of finite length operating in turbulent flow regimes. The thermohydrodynamic solutions are obtained for a journal bearing with four axial grooves. Heshmat and Pinkus' mixing theory (2) is used to evaluate the inlet temperature of each sector. These governing equations are solved to yield pressure, mass-mean velocity and temperature distributions, the mixing temperature at the inlet and the flow rates at the entry and exit of each sector, and the fictional forces.

ISSN:1040-2004    

DOI:10.1080/10402009408983364

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The effect of misalignment on the performance of a complete shell gas foil bearing is discussed. An iterative theoretical model based on the finite element method is used. The model includes membrane and elastic foundation effects in the structural model. An isothermal perfect gas is used as the lubricant fluid. Results are presented demonstrating the effect of misalignment on load capacity, minimum clearance, and moments acting normal to the journal.

ISSN:1040-2004    

DOI:10.1080/10402009408983365

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor