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The purpose of this paper is to introduce a high-speed rolling bearing test rig supported by sliding bearing and its first experimental results.

Through analyzing the disadvantages of using rolling bearing as supporting bearing, the bottlenecks that need to be resolved urgently in the development of rolling bearing experimental technology, and the advantages of the sliding bearing, this study used the sliding bearing as the supporting bearing for the high-speed rolling bearing test rig for the purpose of prolonging the service life, increasing the load capacity and promoting the operating stability.

The experimental results show that the high-speed rolling bearing test rig supported by sliding bearing could stably rotate at 70,800 rpm without installing the test bearing; the temperature of the sliding bearing is increasing with the rotating speed and the maximum is less than 95°C. Moreover, the new test rig, installing an angular contact ball bearing as test bearing, could also stably rotate at 54,000 rpm with 2 kN axial load and 1 kN radial load; the temperature of the sliding bearing is increasing with the rotating speed and the maximum temperature is less than 97°C.

Rolling test rig has been established.

This paper proposes a high-speed rolling bearing test rig supported by sliding bearing, which greatly prolongs the service life, increases the load capacity and promotes the operating stability, moreover, reduces the risk of supporting bearing failure before the test bearing. This paper can also provide a new idea and reference for the design of similar bearing test rig.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2020-0085/

The aim of this paper is to propose a design idea for an infinite journal bearing with the optimized slip zone on the bearing sleeve surface.

The approach is to use finite element analysis and the quadratic programming algorithm to study the performance of the journal bearing with a slip zone on the sleeve surface. The fluid film pressure and slip velocity can be obtained in one solution step.

A journal bearing with a slip zone on the sleeve surface produces many different advantages over the traditional journal bearing. Even in a parallel sliding gap there is still a considerable large load support, but a very low friction drag. The effect of the enhancement of such a slip wedge on the journal bearing performance is much greater at a small eccentricity ratio than at a large eccentricity ratio. Numerical analyses indicate that the location and size of the slip zone greatly affect the journal performance. When the eccentricity ratio ϵ=0.8, the maximum load support is increased by ∼19 per cent and surface friction coefficients reduced by ∼35 per cent and ∼42 per cent at shaft and sleeve surfaces, respectively.

The paper shows how the present concept can be used to design not only a journal bearing but also a thrust bearing with a slip wedge.

The purpose of this paper is to improve the lubrication performance of a water-lubricated polymer bearing with axial grooves, especially enlarge the minimum film thickness.

The bearing diameter is enlarged near the axial ends of the journal, with axial openings of a trumpet shape. A numerical model is developed which considers the proposed trumpet-shaped openings, bush deformation and grooves. The generatrix of the trumpet-shaped opening is assumed to be a paraboloid. Three different variations are covered, and the influences of the trumpet-shaped openings’ parameters on the bearing performance are analyzed.

The appropriate trumpet-shaped openings at the axial ends effectively increase the minimum film thickness, and the impact of trumpet-shaped openings on load carrying capacity is very small or even negligible. For the water-lubricated polymer bearing with axial grooves analyzed in this paper, the appropriate trumpet-shaped openings increase the minimum film thickness from 0.53 to 11.14 µm and decrease the load carrying capacity by 2.48 per cent.

The results of this study can be applied to marine propeller shaft systems and other systems with polymer bearings.

This paper has presented an approach for significantly increasing the minimum film thickness of a water-lubricated polymer bearing. A study on the performance improvement of water-lubricated polymer bearings with axial grooves is of significant interest to the research community.

Current lubrication analyses of misaligned journal bearings were generally performed under some given preconditions. To make the lubrication analysis closer to the actual situation and usable to the journal bearing design, the purpose of this paper was to calculate the lubrication characteristics of misaligned journal bearings considering the viscosity-pressure effect of the oil, the surface roughness and the elastic deformation of the journal bearing at the same time.

The lubrication of bearings was analyzed using the average Reynolds equation. The deformation of the bearing surface under oil film pressure was calculated by a compliance matrix method. The compliance matrix was established by finite element analysis of the bearing housing. The viscosity-pressure and viscosity–temperature equations were used in the analysis.

The oil viscosity-pressure relationship has a significant effect on the lubrication of misaligned journal bearings. The surface roughness will affect the lubrication of misaligned journal bearings when the eccentricity ratio and angle of journal misalignment are all large. The directional parameter of the surface has an obvious effect on the lubrication of misaligned journal bearings. The deformation of the bearing surface has a remarkable effect on the lubrication of misaligned journal bearings.

The lubrication characteristics of misaligned journal bearings were calculated considering the viscosity-pressure effect of the oil, the surface roughness and the elastic deformation of the journal bearing at the same time. The results of this paper are helpful to the design of the bearing.

The form error of shaft and hole parts is inevitable because of the machining error caused by rotation error of tool axis in machine tools where the elliptical form error is the most common in shaft and bearing bush. The purpose of this paper is to present the relationship between the elliptical form error and rotation accuracy for hydrostatic journal bearing in precision spindle and rotation table.

An error averaging effect model of hydrostatic journal bearing is established by using Reynolds equation, pressure boundary conditions, flux continuity equation of the land and kinetic equation of shaft in hydrostatic journal bearing. The effects of shaft and bearing bush on rotation accuracy were analyzed quantitatively.

The results reveal that the effect of shaft elliptical form error on rotation accuracy was six times larger than bearing bush. Therefore, to improve the rotation accuracy of hydrostatic journal bearing in spindle or rotation table, the machining error of shaft should be controlled carefully.

An error averaging model is proposed to evaluate the effect of an elliptical form error on rotation accuracy of hydrostatic journal bearings, which solves the Reynolds equation, the flux continuity equation and the kinetic equation. The determination of form error parameters of shaft and bearing bush can be yielded from finding results of this study for precision design of hydrostatic journal bearings.

Hole‐entry hybrid journal bearings are widely used in many applications owing to their favourable characteristics. Ever increasing technological developments demand much improved performance from these class of bearings operating under the most stringent, exact and precise conditions. Therefore, it becomes imperative that the hole‐entry journal bearings be designed on the basis of more accurately predicted bearing characteristics data. The purpose of this paper is to describe a theoretical study to demonstrate the combined influence of the effect of pocket size at the outlet of supply holes and the journal misalignment on the performance of an orifice compensated hole‐entry hybrid journal bearing system.

Finite element method is used to solve the Reynolds equation governing the flow of an incompressible lubricant in the clearance space between the journal and bearing together with equation of flow through an orifice. The journal misalignment has been accounted for by defining a pair of misalignment parameters sigma and delta. The effect of pocket size at the outlet of supply holes has been accounted by defining a non‐dimensional parameter which is function of diameter of pocket and journal diameter.

The results presented in this paper indicate that the effect of journal misalignment is, in general, to cause a reduction in bearing dynamic characteristics parameters whereas the effect of pocket size is to slightly compensate this loss. Performance of a two lobe four recessed journal bearing, a proper selection of bearing offset factor along with type of restrictor (capillary or orifice) is essential.

This paper presents valuable data relating to hole‐entry hybrid journal bearings useful for bearing designers.

This study aims to uncover the influencing mechanism of the tilt angles of the cage pocket walls of the high-speed cylindrical roller bearing on the bearing skidding.

A novel cylindrical roller bearing with the beveled cage pockets was proposed. Using the Hertz contact theory and the elastohydrodynamic and hydrodynamic lubrication formulas, the contact models of the bearing were built. Using the multibody kinematics and the Newton–Euler dynamics theory, a dynamics model of the bearing was established. Using the Runge–Kutta integration method, the dynamics simulations and analysis of the bearing were performed.

The simulation results show that the effects of the tilt angles of the front and rear walls of the pocket on the bearing skidding are remarkable. Under a 5° tilt angle of the front wall of the pocket and a 10° tilt angle of the rear wall, the bearing skidding can be effectively decreased in the rotational speed range of 10,000-70,000 r/min.

In this paper, a novel cylindrical roller bearing with the beveled cage pockets was proposed; a dynamics model of the bearing was established; the influence mechanism of the tilt angles of the front and rear walls of the pocket on the bearing skidding was investigated, which can provide fundamental theory basis for optimizing the pocket.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0035/

The paper aims to devise an externally adjustable fluid film bearing whereby the hydrodynamic conditions can be changed as required in a controlled manner. Unlike a tilting pad bearing, in this bearing film thickness can be varied by providing radial and tilt adjustments to the pad, irrespective of the operating conditions. This variation in film thickness in‐turn varies the stiffness and damping coefficients.

The stability characteristics of a centrally loaded 120° single pad externally adjustable fluid film bearing is studied theoretically. The bearing has an aspect ratio of one and operates over a wide range of eccentricity ratios and adjustments. The time dependent form of Reynolds equation in two dimensions is solved numerically using the finite difference method. Dynamic performance characteristics of the bearing are in terms of film stiffness and damping coefficients, critical mass of the journal and the whirl frequency ratio. Stability is determined using a first‐order‐linear‐perturbation method.

The paper finds that a study with various adjustments predicts that negative radial and negative tilt adjustment configuration results in superior dynamic characteristics as compared to a conventional fluid film bearing.

It is possible to have a particular set of radial and tilt adjustments that will provide a stable operation of the rotor bearing system. Single pad externally adjustable fluid film bearing will perform as a conventional partial arc bearing when both the adjustments are set to zero.

Under the action of many factors, the shaft of the shaft-journal bearing system inevitably moves along the axis direction at work, which will lead to the axial movement of journal in the bearing. However, at present, only the dynamic and squeezing effects caused by the relative rotation and squeezing motion between the journal and the bearing surfaces are considered in the lubrication analysis of misaligned journal bearing and the axial movement of journal in the actual use of bearing is not considered. The purpose of this paper is to analyze the lubrication of journal bearing considering the axial movement of journal.

Taking the shaft-journal bearing system as the research object, a hydrodynamic lubrication model of journal bearing is established considering the axial movement and misalignment of journal. The finite difference method is used to solve the Reynolds equation for the lubrication analysis.

The axial movement of journal has a significant influence on the lubrication characteristics of misaligned journal bearing. The larger the misalignment angles of journal or the eccentricity of bearing, the greater the influence of the axial movement of journal on the lubrication performance of bearing. The lower the speed of bearing or the smaller the clearance of bearing, the more significant the influence of the axial movement of journal on the lubrication performance of bearing is.

The influence of the axial movement of journal on the lubrication performance of journal bearing is studied under different misalignment angles of journal, working conditions and clearances of bearing. The results of this paper are helpful to the design and research of the lubrication performance of journal bearing.

This paper aims to develop a simulating model of a journal porous metal bearing under elastohydrodynamic conditions and combined (radial, friction and thermal) load distribution and to carry out structural optimization.

The structure analysis is carried out for each kind of load separately and for the combined load distribution of the bearing, where a dynamically loaded porous metal bearing is simulated. This simulating model is developed by finite elements method using the structure analysis module of the CATIA V5 software. Further, a parameter optimization of a porous metal bearing is presented considering the elastic deformations of the bearing shell.

It is revealed that the bearing, even at points with maximum displacements, could not reach the mounting clearance value during its operational life. Relatively small bearing dimensions produce very high values of eigenfrequency response (over 150 kHz) and common dynamic loads met in all sorts of sliding bearing are not dangerous for bearing damage compared with static loads. In the stage of structural optimization based on the correlation between stress and geometric bearing parameters like wall thickness and outer diameter, the influence of finite element dimension on calculated results can be also analyzed and a proper choice of the latter is achieved.

The present porous bearing optimization model with the aid of CATIA V5 module for optimum design uses only single objective optimization. For a complete optimum design a multi‐objective optimization has to be carried out.

The analysis under dynamic load conditions proved that relatively small dimensions of bearing commonly used in micro technique and precision mechanics result in extended safe and reliable operation.

This paper provides a methodology for bearing stress and deformation analysis in the elastic range and on the basis of this analysis it is possible to develop an optimization model for porous bearings offering help to designers for the selection of optimal bearing dimensions considering the bearing load caused by dynamic radial force, friction and temperature variation.