Papers by Keyword: Bearing

Abstract: The article presents comparative data on the properties of different materials used for the manufacture of bearings. The influence of the chemical composition and structure of titanium-based alloys on the change in hardness during various types of processing is studied. It is shown that the most promising for the manufacture of bearings are high-alloyed titanium alloys of the VT22 type, in which the hardening heat treatment allows to obtain a high hardness.

Abstract: The rolling contact fatigue (RCF) tests of 13Cr-2Ni-2Mo and SUS440C stainless steels were carried out in water. Their groove surfaces and the flaking failures were observed. Some hair cracks, wear and high roughness area were found. While the flaking depth of SUS440C was shallower than that of 13Cr-2Ni-2Mo stainless steel, the RCF life of the latter was longer than the former one. The flaking depth did not influence the RCF life.

Abstract: This work aims to study the prediction of bearing capacity of prestressed concrete beams subjected to accelerated corrosion process using Machine Learning (ML) techniques. After data collection, the results were used to model the behavior of flexural stress, and predict their final load capacity, considering position, length, and width of the cracks generated by corrosion as well as loss of bearing capacity. The study presents an analysis of 363 days old beams damaged by corrosion, connected to a galvanostat for 62, and 121 days to make faster the process. Six beams were analyzed; five of them were used to train the model, the other works as a basis to compare the results thrown by the model with the real data. After the treat, the results showed that Bagged Trees Model fits better to real data, it was seen that removing atypical data improves the correlation of predicted and real data. The actual data were compared with two different prediction analyzes; for the first one, the atypical data were not removed; in the second one, the atypical data were eliminated with a statistical analysis. Obtaining relative error percentages of 15.18%, 14.59%, presenting two predictions: final load of 1444 kg and 1126 kg. Which means a resistant moment of 650 T-m, and 506.7 T-m respectively, taking as a prediction the second value in the safe side.

Abstract: Fluxing and tinning processes are usually used to improve the adhesion of the Al bearing layer on steel substrate. Commonly after grinding the surface of the steel substrate, it is briefly immersed in flux solution followed by coating steel surface with either pure Sn (in a process known as tinning process) to promote adhesion between the bearing alloys and the steel. The current work is designated to investigate the influence of tinning material for carbon steel substrate using simultaneous fluxing and tinning mixture technique. The influence of three different tinning materials on the interface structure and shear strength of cast Al-Sn bearing alloy/steel bimetal composite is evaluated for compound casting technique. Sn pure, Sn-3Cu alloy and Sn-7.5Sb-3Cu powder alloys mixed individually with flux are used as tinning materials. It was found that using of different tinning materials have a significant effect on the bonding of interface area and the shear strength of interface as well. The shear strength of the bimetal fabricated using tinning mixture contains Sn+3% Cu with flux significantly increases by 59% compared to that fabricated using tinning mixture contains pure Sn. This increment is mainly due to the improvements of the interface bond structure and lower percentage of tin oxides. Such kind of phenomena can be explained in the fact that Cu minimizes the possibility of Sn oxidation during tinning process and during preheating of tinned steel substrate before casting of Al12Sn4Si1Cu bearing alloy as well.

Abstract: Influence of roughness on conventional hydrodynamic lubrication of tilted pad thrust slider bearing is studied. Roughness effect is studied using Christensen stochastic process. To study the effect of roughness, bearing characteristics like load carrying capacity is analyzed.

Abstract: Many machine components work within an elastohydrodynamic lubrication (EHL) regime. Unconfined space is widely used in EHL formulas for to evaluate film thickness, which is related to operating conditions and material properties. In classical theoretical EHL studies, film pressure matches the loading balance and the location of the lubricated components can be adjusted. In the present study, the lubrication performance is analyzed based on a confined space. A thrust ball bearing lubrication simulation system is designed and used to examine the relationship between velocity and film thickness. It was found that the central film thickness and minimum film thickness increased as entrainment velocity increased. Fluctuations in the film thickness curve were observed, which may have arisen from slight gap variations in the ball-plate contact area.

Abstract: Fault diagnosis of train bearing is an important method to ensure the security of railway. In the paper, four time domain statistical analysis methods and resonance demodulation method as a frequency domain analysis method are introduced. A state inspection and fault diagnosis system of train axel box bearing is constructed and its efficiency is also tested by wheel set experiment.

Abstract: Tilting (parallelism error) of guiding surfaces may cause reduction of load capacity of hydrostatic (HS) guideways and bearings in machine tools (MT). Using coupled finite element (FE) computational models of MT structures, it is nowadays possible to determine the extent of guiding surfaces deformation caused by thermal effects, gravitational force, cutting forces and inertia effects. Assessment of maximum allowable tilt has so far been based merely on experience. The paper presents a detailed model developed for description of the effect of HS bearing tilt on the load capacity characteristics of HS guideways. The model allows an evaluation of the tilt influence on the change of the characteristics as well as determination of the limit values of allowable tilt in interaction with compliant machine tool structure. The proposed model is based on the model of flow over the land of the HS pocket under extended Navier-Stokes equation. The model is verified using an experimental test rig.

Abstract: The Francis turbine in water power plant station is positioned at top and bottom axial hanging bearings. During reparation work the turbine was disassembled and during assembling the adjusting segments in the hanging bearings were released. In the paper are described procedures that are necessary in order to provide correct distribution of axial forces in twelve segments of upper axial hanging bearing by strain-gages applied on elastic pipes positioned under individual bearing segments.

Abstract: In contextual evolution of the global economy and new technologies, quality, competitiveness, and cost engage companies to focus on continuous improvement and innovation. This approach is highly visible in the bearing industry, due to the emergence and improvement of existing and new types of bearings.The authors of the paper are engaged in a long-term research, which aims to improve the performance of heavy bearings, including identification of new constructive solution. The study is focused on the characteristics and constructive structure of the bearings cages in discussion.In this context, it is logical that the research focuses upon known bearings cages that are currently used [1], as well as unknown or unapplied constructive solutions which are the subject of patents.The critical analysis of various constructive cage solutions for bearings, intended or not for heavy bearings, is a valuable source of inspiration and information towards identification of constructive elements and characteristics useful to develop new technical solutions, by applying integrations, combinations, innovations and development processes [2].In the presented paper several patents are analyzed critically [3, 4, 5], in terms of constructive solutions, manufacturing complexity and presumptive operational energy consumption.