scholarly journals Manufacturing and Evaluation of Multi-Material Axial-Bearing Washers by Tailored Forming

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 232 ◽  
Author(s):  
Bernd-Arno Behrens ◽  
Alexander Chugreev ◽  
Tim Matthias ◽  
Gerhard Poll ◽  
Florian Pape ◽  
...  
Keyword(s):  
Layer Structure ◽  
Roller Bearing ◽  
Welding Process ◽  
Rolling Contact ◽  
Acoustic Microscopy ◽  
Research Centre ◽  
Forming Process ◽  
Rolling Bearings ◽  
Cylindrical Roller ◽  
Tailored Forming

Components subject to rolling contact fatigue, such as gears and rolling bearings, are among the fundamental machine elements in mechanical and vehicle engineering. Rolling bearings are generally not designed to be fatigue-resistant, as the necessary oversizing is not technically and economically marketable. In order to improve the load-bearing capacity, resource efficiency and application possibilities of rolling bearings and other possible multi-material solid components, a new process chain was developed at Leibniz University Hannover as a part of the Collaborative Research Centre 1153 “Tailored Forming”. Semi-finished products, already joined before the forming process, are used here to allow a further optimisation of joint quality by forming and finishing. In this paper, a plasma-powder-deposition welding process is presented, which enables precise material deposition and control of the welding depth. For this study, bearing washers (serving as rolling bearing raceways) of a cylindrical roller thrust bearing, similar to type 81212 with a multi-layer structure, were manufactured. A previously non-weldable high-performance material, steel AISI 5140, was used as the cladding layer. Depending on the degree of forming, grain-refinement within the welded material was achieved by thermo-mechanical treatment of the joining zone during the forming process. This grain-refinements lead to an improvement of the mechanical properties and thus, to a higher lifetime for washers of an axial cylindrical roller bearing, which were examined as an exemplary component on a fatigue test bench. To evaluate the bearing washers, the results of the bearing tests were compared with industrial bearings and deposition welded axial-bearing washers without subsequent forming. In addition, the bearing washers were analysed micro-tribologically and by scanning acoustic microscopy both after welding and after the forming process. Nano-scratch tests were carried out on the bearing washers to analyse the layer properties. Together with the results of additional microscopic images of the surface and cross-sections, the causes of failure due to fatigue and wear were identified.

Influences of Additives on the Wear Protection of PVD-Coated and Ester Lubricated Roller Thrust Bearings

2005 ◽  
Author(s):  
P. W. Gold ◽  
J. Loos ◽  
M. Kuhn
Keyword(s):  
World Wide ◽  
Roller Bearing ◽  
Boundary Friction ◽  
Extreme Pressure ◽  
Pvd Coatings ◽  
Test Rig ◽  
Rolling Bearings ◽  
Thrust Bearings ◽  
Wear Protection ◽  
Cylindrical Roller

Mixed friction cannot always be avoided in rolling bearings. It is therefore necessary to protect the bearings against wear. Nowadays, extreme-pressure- and anti-wear-additives fulfill this function. As these additives are harmful to the environment it was systematically examined to what extent PVD-coatings are able to take over their function. The effectiveness of the coatings was tested in the FE8 lubricant roller bearing test rig on the basis of cylindrical roller thrust bearings. With the help of this world wide established test rig the roller bearings are tested on boundary friction conditions (κ ≪ 1).

scholarly journals Introduction to tailored forming

2021 ◽  
Author(s):  
B.-A. Behrens ◽  
J. Uhe
Keyword(s):  
Collaborative Research ◽  
Lightweight Design ◽  
Production Quality ◽  
Research Centre ◽  
Lightweight Construction ◽  
Forming Process ◽  
Process Chains ◽  
Finishing Processes ◽  
Tailored Forming ◽  
Joining Process

AbstractIn recent years, the requirements for technical components have been increasing steadily. This development is intensified by the desire for products with lower weight, smaller size and extended functionality, but at the same time higher resistance against specific loads. Mono-material components manufactured according to established processes reach their limits regarding conflicting requirements. It is, for example, hardly possible to combine excellent mechanical properties with lightweight construction using mono-materials. Thus, a significant increase in production quality, lightweight design, functionality and efficiency can only be reached by combining different materials in one component. The superior aim of the Collaborative Research Centre (CRC) 1153 is to develop novel process chains for the production of hybrid solid components. In contrast to existing process chains in bulk metal forming, in which the joining process takes place during forming or at the end of the process chain, the CRC 1153 uses tailored semi-finished workpieces which are joined before the forming process. This results in a geometric and thermomechanical influence on the joining zone during the forming process which cannot be created by conventional joining techniques. The present work gives an overview of the CRC and the Tailored Forming approach including the applied joining, forming and finishing processes as well as a short summary of the accompanying design and evaluation methods.

Elastohydrodynamic Lubrication of Roller Bearings

1970 ◽  
Vol 92 (2) ◽  
pp. 281-288 ◽  
Author(s):  
J. C. Skurka
Keyword(s):  
Surface Finish ◽  
Roller Bearing ◽  
Elastohydrodynamic Lubrication ◽  
Rolling Contact ◽  
Bearing Life ◽  
Endurance Tests ◽  
Tapered Roller ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller ◽  
Lubricant Viscosity

Roller bearing endurance tests have been run on groups of bearings with L10 and L50 lives established by Weibull analysis. Bearing roller path surface finish, shaft speed, lubricant viscosity and lubricant temperature were varied. Relevant tapered roller and cylindrical roller bearing life data was selected from prior tests for comparison. Weibull plots show the effect of the variables on life and a graph comparing the ratio of L10 test life to the calculated life and the ratio of elastohydrodynamic lubricant film thickness to composite rolling contact surface finish is given. An empirical equation to predict the effect of varying lubricant and surface finish conditions on fatigue life is given.

scholarly journals Influence of manufacturing errors of bearing components on rotational accuracy of cylindrical roller bearings

2021 ◽  
Author(s):  
Yongjian Yu ◽  
Jishun Li ◽  
Yujun Xue
Keyword(s):  
Coupling Effect ◽  
Roller Bearing ◽  
Contributing Factors ◽  
Rolling Bearings ◽  
Motion Error ◽  
Manufacturing Errors ◽  
Manufacturing Tolerances ◽  
Component Manufacturing ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

Abstract Understanding the influence of bearing component manufacturing errors and roller number on the rotational accuracy of rolling bearings is crucial in the design of high precision bearings. The rotational accuracy of an assembled bearing is dependent upon roller number and manufacturing error of the bearing components. We propose a model for calculating the rotational accuracy of a cylindrical roller bearing; we experimentally verified the effectiveness of the model in predicting the radial run-out of the inner ring proposed in the previous paper in this series. We sought to define the key contributing factors to the rotational accuracy by studying both the influence of the coupling effect of the roller number and the influence of the manufacturing errors in the inner raceway, outer raceway, and rollers on the motion error. The model and results will help engineers choose reasonable manufacturing tolerances for bearing components to achieve the required rotational accuracy.

scholarly journals Investigations on Tailored Forming of AISI 52100 as Rolling Bearing Raceway

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1363
Author(s):  
Timm Coors ◽  
Maximilian Mildebrath ◽  
Christoph Büdenbender ◽  
Felix Saure ◽  
Mohamad Yusuf Faqiri ◽  
...  
Keyword(s):  
Fatigue Behavior ◽  
Base Material ◽  
Rolling Bearing ◽  
Bearing Steel ◽  
Rolling Contact ◽  
Acoustic Microscopy ◽  
Process Step ◽  
Small Depth ◽  
Aisi 52100 ◽  
Tailored Forming

Hybrid cylindrical roller thrust bearing washers of type 81212 were manufactured by tailored forming. An AISI 1022M base material, featuring a sufficient strength for structural loads, was cladded with the bearing steel AISI 52100 by plasma transferred arc welding (PTA). Though AISI 52100 is generally regarded as non-weldable, it could be applied as a cladding material by adjusting PTA parameters. The cladded parts were investigated after each individual process step and subsequently tested under rolling contact load. Welding defects that could not be completely eliminated by the subsequent hot forming were characterized by means of scanning acoustic microscopy and micrographs. Below the surface, pores with a typical size of ten µm were found to a depth of about 0.45 mm. In the material transition zone and between individual weld seams, larger voids were observed. Grinding of the surface after heat treatment caused compressive residual stresses near the surface with a relatively small depth. Fatigue tests were carried out on an FE8 test rig. Eighty-two percent of the calculated rating life for conventional bearings was achieved. A high failure slope of the Weibull regression was determined. A relationship between the weld defects and the fatigue behavior is likely.

The effect of round corner on lubrication of high speed cylindrical roller bearings considering skidding

2017 ◽  
Vol 69 (6) ◽  
pp. 833-843 ◽  
Author(s):  
Wei Cao ◽  
Jiaxu Wang ◽  
Wei Pu ◽  
Ying Zhang ◽  
Jiqiang Wu ◽  
...  
Keyword(s):  
Optimization Design ◽  
Roller Bearing ◽  
Rolling Contact ◽  
Maximum Pressure ◽  
Operating Condition ◽  
Content Type ◽  
Corner Radius ◽  
Lubrication Performance ◽  
Cylindrical Roller ◽  
Inner Race

Purpose Previous studies were mainly focused on profile designation of bearing rollers and lubrication performance without considering roller-races skidding. However, the width of round corner, load, rotational speed and some other parameters have significant effects on the roller-races sliding speed. This paper aims to investigate the effect of round corner on lubricating characteristics between the heavily loaded roller and inner race considering skidding and roughness. Design/methodology/approach A mixed elastohydrodynamic lubrication (EHL) model which is capable of handling practical cases with 3D machined roughness is combined with the skidding model to investigate the effect of round corner on lubricating characteristics between the heavily loaded roller and inner race. Findings The width of round corner and round corner radius have a desirable range under certain operating condition, within which the maximum pressure, stress and maximum flash temperature remain low. The optimized range is sensitive to the operating condition. Roughness and skidding narrow the optimized range of round corner radius. Roughness increases the pressure peak, Mises stress and friction coefficient. At the same time, skidding and roughness have obvious effects on film thickness at the contact center area if the round radius is small. Research limitations/implications This paper uses the Harris skidding model that has a relatively bigger error, which is not accurate if the bearing load is less. Practical implications This paper unifies the skidding model and mixed EHL model which can be used as a tool for optimization design and lubricating performance analysis of cylindrical roller bearing. Originality/value Lubrication analyses for roller bearing are assumed to be pure rolling contact between roller and races in a previous study, which could not reflect the real contact characteristics. The skidding model is merged into a mixed EHL model which can be used as a dynamic tool to analyze the lubricating performance considering the round corner, skidding and roughness.

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