Rolling bearings. Needle roller bearing track rollers. Boundary dimensions and tolerances

2015 ◽  
Keyword(s):  
Roller Bearing ◽  
Rolling Bearings

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.

scholarly journals Study on the Thermal Distribution Characteristics of High-Speed and Light-Load Rolling Bearing Considering Skidding

2018 ◽  
Vol 8 (9) ◽  
pp. 1593 ◽  
Author(s):  
Junning Li ◽  
Jiafan Xue ◽  
Zhitao Ma
Keyword(s):  
Temperature Distribution ◽  
Power Loss ◽  
High Speed ◽  
Roller Bearing ◽  
Transient Temperature ◽  
Rolling Bearings ◽  
Slip Ratio ◽  
Friction Power ◽  
Thermal Distribution ◽  
Light Load

Skidding, which frequently occurs in high-speed rolling bearings, has a significant effect on the thermal distribution and service reliability of the bearings. An improved theoretical model of friction power loss distribution in high-speed and light-load rolling bearings (HSLLRBs) considering skidding is established, and the effects of various operating parameters on the friction power loss are investigated. The results show that the friction power loss of the inner ring and outer ring as well as the total friction power loss of the bearing increase as the slip ratio increases, but that the friction power loss of the cage guide surface and roller oil churning show a reverse trend. In addition, the increase in inner ring speed and kinematic viscosity leads to an increase in bearing friction power loss. The steady and transient temperature field distribution of HSLLRBs is obtained by the finite element method (FEM), and the results show that the inner ring raceway has the highest temperature, whereas the cage has the lowest. The temperature distribution test rig of a full-size roller bearing is constructed, and the influence mechanism of the slip ratio, rotation speed, load, lubrication, and surface topography on the bearing temperature distribution are obtained. The experimental results are consistent with the theoretical results, which also validates the theoretical method.

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).

Characteristics and Mechanical Properties of Rolling-Element Bearings

2016 ◽  
Vol 8 (3) ◽  
Author(s):  
Lv Haiting
Keyword(s):  
Mechanical Properties ◽  
Load Distribution ◽  
Large Scale ◽  
Roller Bearing ◽  
Rolling Bearing ◽  
Fe Model ◽  
Rolling Bearings ◽  
Angle Variation ◽  
Supporting Structure ◽  
The Impact

Large rolling bearings are mainly used in occasions of low speed and heavy load due to its desirable properties such as large-scale structure and high bearing capacity. Currently, the research emphases of large rolling bearings are focussed on the load distribution, load carrying capacity, fatigue life and structure optimization. Bearings used in heavy vehicles belong to large bearings, whose reliability is also very important. In this paper, the characteristics of the structures of four point angular contact ball bearings and three row cylindrical roller bearing are analyzed. Finite element (FE) model is used to simulate the load distribution and angle variation in the actual working process of a large rolling bearing. In order to analyze the impact of the constraints, the stiffness and the local hard point of the supporting structure on the mechanical properties of large rolling bearings, a series of simplified FE models of large rolling bearing with different constraints and supporting structure has been carried out.

scholarly journals Utilizing SVD and VMD for Denoising Non-Stationary Signals of Roller Bearings

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 195
Author(s):  
Qinghua Wang ◽  
Lijuan Wang ◽  
Hongtao Yu ◽  
Dong Wang ◽  
Asoke K. Nandi
Keyword(s):  
Roller Bearing ◽  
Singular Values ◽  
Difference Spectrum ◽  
Rolling Bearings ◽  
Mode Decomposition ◽  
Effective Components ◽  
Stationary Signals ◽  
The Difference ◽  
Band Limited ◽  
Value Decomposition

In view of the fact that vibration signals of rolling bearings are much contaminated by noise in the early failure period, this paper presents a new denoising SVD-VMD method by combining singular value decomposition (SVD) and variational mode decomposition (VMD). SVD is used to determine the structure of the underlying model, which is referred to as signal and noise subspaces, and VMD is used to decompose the original signal into several band-limited modes. Then the effective components are selected from these modes to reconstruct the denoised signal according to the difference spectrum (DS) of singular values and kurtosis values. Simulated signals and experimental signals of roller bearing faults have been analyzed using this proposed method and compared with SVD-DS. The results demonstrate that the proposed method can effectively retain the useful signals and denoise the bearing signals in extremely noisy backgrounds.

scholarly journals The Impact of Vibration Operational Reliability of Turning Mechanism of Gantry and Tower Cranes

2021 ◽  
pp. 92-101
Author(s):  
Тengiz Chkhaidze ◽  
◽  
Gabriel Merabishvili ◽  
Alexander Metreveli ◽  
◽  
...  
Keyword(s):  
Roller Bearing ◽  
Low Frequency ◽  
Kinematic Chain ◽  
Structural Features ◽  
Operational Reliability ◽  
Rolling Bearings ◽  
Retaining Ring ◽  
Turning Mechanism ◽  
The Impact ◽  
Structural Solutions

Impacts of vibration on operational reliability of turning mechanisms of gantry and rower cranes are considered. Besides that, the structural features of kinematic chain of drive, including gear transmission with internal large module teeth, roller bearing without retaining ring, excitement of torsional, bending low-frequency vibrations at operation in nominal mode of cargo lifting that causes the origination of of increasing friction moment and stop of turning mechanism are researched in this article. Moreover, the technological and structural solutions aimed on decreasing of excited vibrations are proposed, and the supporting-rotating rolling bearings without retaining ring with improved technical-economic indicators are considered.

scholarly journals Mechanical Characterisation of the Coated Roller Bearing

2019 ◽  
Vol 8 (4) ◽  
pp. 10943-10945
Keyword(s):  
Surface Topography ◽  
Roller Bearing ◽  
Coating Material ◽  
Remaining Useful Life ◽  
Rolling Bearings ◽  
Bearing Material ◽  
Mechanical Characterisation ◽  
Different Types ◽  
Useful Life ◽  
Load Conditions

Due to increase demand of rotating elements in various fields of mechanical, electronics and fluid industry there is a need for moving elements like rolling bearings. Since the supporting member is rolling bearings hence in this work we are trying to improve the performance by studying the structure of the material present in the bearing, type of optimised coating i.e by polytetra fluroethylene coating.coating an optimum layer of 0.05mm thickness and checking the performance at different speeds and various load conditions is examined .the surface topography after coating is checked using sem technique and the discussions are made. Comparison of different types of bio grease for the coated bearing material. Capturing these vibrations of the bearing using vibrometers and accelerometers and improving the remaining useful life of the bearing by changing the type of coating material.

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