scholarly journals The dependence of performance characteristics of roller bearing on material used

2021 ◽  
pp. 41-45
Author(s):  
D. B. Grits ◽  
Keyword(s):  
Roller Bearing ◽  
Contact Stresses ◽  
Rolling Stock ◽  
Steel Shkh15 ◽  
Alternative Materials ◽  
Rolling Elements ◽  
Bearing Assembly ◽  
Bearing Rings ◽  
Maximum Contact ◽  
12Kh18n9t Steel

The main materials for the manufacture of rolling stock bearing assemblies are steel ShKh15, ShKh15SG, ShKh4. The article discusses the possibility of using steels 20Kh2N4A, 95Kh18-Sh, 12Kh18N9T as alternative materials, an assessment of the arising contact stresses on the surfaces of the raceways of the bearing rings and rolling elements is given. When using 12Kh18N9T steel, the maximum contact stresses are reduced by 4 % in comparison with standard materials, which can provide an increase in the resource of the bearing assembly.

Analysis of a Rolling-Element Idler Gear Bearing Having a Deformable Outer-Race Structure

1963 ◽  
Vol 85 (2) ◽  
pp. 273-278 ◽  
Author(s):  
A. B. Jones ◽  
T. A. Harris
Keyword(s):  
Fatigue Life ◽  
High Speed ◽  
Roller Bearing ◽  
Rolling Element Bearing ◽  
Outer Ring ◽  
Outer Race ◽  
Rolling Element ◽  
Rolling Elements ◽  
Planet Gear ◽  
Bearing Rings

Conventional calculations of ball and roller bearing carrying capacity and fatigue life assume that the raceway bodies are rigid structures and that all elastic deformation occurs at the rolling elements’ contact with the raceways. In many instances, and particularly with aircraft applications, the bearing rings and their supports cannot be considered rigid. One such application is the planet gear in a transmission. This report develops a theory whereby the effects of the elastic distortions of the outer race of a rolling-element bearing on the internal load distribution and fatigue life of the bearing can be considered. The theory has been programmed for a high-speed, digital computer. An example of calculation for a planet gear roller bearing whose outer race is integral with the gear and of relatively thin section is given. The distortions of the flexible outer ring cause a significantly lower bearing fatigue life (L10) than would occur if the outer ring were rigid and considering a practical range of bearing diametral clearances. Mr. Jones developed the theoretical analysis for this paper and Mr. Harris provided the programming and the experimental data.

scholarly journals CYLINDRICAL ROLLER BEARING LUBRICATION REGIMES ANALYSIS AT LOW SPEED AND PURE RADIAL LOAD

2019 ◽  
Vol 59 (3) ◽  
pp. 272-282
Author(s):  
Jakub Chmelař ◽  
Karel Petr ◽  
Petr Mikeš ◽  
Vojtěch Dynybyl
Keyword(s):  
Roller Bearing ◽  
Radial Load ◽  
Lubrication Regimes ◽  
Lubrication Film ◽  
Press Fit ◽  
Lubrication Regime ◽  
Rolling Element ◽  
Rolling Elements ◽  
Cylindrical Roller Bearing ◽  
Bearing Rings

In this article, we describe a method of the roller bearing lubrication regime prediction. It uses a mathematical model of the bearing based on the standard ISO/TS 16281 to obtain the external load distribution over the rolling elements. We consider the effects of press fit and thermal gradient etween bearing rings on the internal clearance. The model is limited to an input of an uni-axial radial load and it neglects the centrifugal forces and gyroscopic moments due to its application for the region of low speeds. The lubrication film thickness is evaluated for the most loaded rolling element by a numerical solution of Reynolds’ equation for the line contact. The assessment of the lubrication regime takes into the account the surface roughness by employing the lubrication coefficient as an output parameter. Presented outcomes of the study, based on the measured geometry of the bearing, show the importance of an appropriate lubricant selection for the application.

scholarly journals Method to determine the local load cycles of a blade bearing using flexible multi-body simulation

2021 ◽  
Author(s):  
S. Leupold ◽  
R. Schelenz ◽  
G Jacobs
Keyword(s):  
Load Distribution ◽  
Structural Components ◽  
Rolling Bearings ◽  
Average Accuracy ◽  
Rolling Elements ◽  
Flexible Integration ◽  
Multi Body ◽  
Bearing Rings ◽  
Maximum Contact

AbstractConventional methods for designing rolling bearings against fatigue assume that a bearing ring is fully rotating and that the load is ideally distributed over the rolling elements. Blade bearings in wind turbines, are operated under oscillating motions and dynamic loads. The load distribution is strongly dependent on the stiffness of the bearing rings and the surrounding structural components. This has been shown in numerous studies using FEM simulations for static load cases. In this paper a method is presented that reduces the calculation effort of the deformation of the bearing rings, so that a flexible integration into an aeroelastic mbs model of a wind turbine is possible. Thereby an average accuracy of 6.5% between FEM and mbs could be achieved. The model allows the determination of time series of the global load distribution of each raceway. By data processing of the simulation results, the number of load cycles and the maximum contact pressure for individual segments of the raceways could be determined and their fatigue probability could be estimated using the linear damage hypothesis according to Palmgren-Miner.

scholarly journals Design and manufacture of the novel drum worm pair

2020 ◽  
Vol 103 (4) ◽  
pp. 003685042098122
Author(s):  
Jingzi Zhang ◽  
Jin’ge Wang ◽  
Kai Wang
Keyword(s):  
Contact Stresses ◽  
Primary Objective ◽  
Structure Design ◽  
Worm Gear ◽  
The Novel ◽  
Bending Stress ◽  
Manufacturing Method ◽  
Design And Manufacture ◽  
Maximum Contact ◽  
Worm Drive

Although a significant amount of research on robot joint reducer was conducted, there are few systematic investigations on a novel joint reducer adopting inner worm-gear plane enveloping drum worm drive. To satisfy the development of modular robot joint, the primary objective of this paper was to systematically investigate the drum worm drive adopted in the novel joint reducer with integrated structure of drive, transmission, and support in the following aspects: meshing theory, design, analysis, and manufacture. According to the gear meshing theory, mechanical design method, classical mechanics, finite element method, and machining principle of virtual center distance, the systematic investigations around the drum worm pair applied in the novel joint reducer were conducted including the macro and micro meshing theory, structure design, mechanical and contact properties analyses, and manufacturing method. The novel joint reducer’s integrated structure was designed, and the drum worm pair’s mechanical and contact properties analyses were conducted, which showed: (1) the worm’s bending stress and deflection, worm-gear teeth’s shear stress and bending stress as well as the maximum contact stresses were all below their corresponding allowable values; (2) the maximum contact stresses appeared at the engage-in position of the worm pair opposing to the engaging-out position where the largest contact areas appeared. Then the manufacturing of drum worm’s spiral tooth was conducted via the modified 4-axis linkage CNC grinder according to the conjugate motion. Finally the novel joint reducer’s industrial prototype was assembled. The novel joint reducer with integrated structure of drive, transmission and support was designed and manufactured for the first time. The flowchart of design and manufacture of the reducer’s drum worm pair in this process was formulated, which provides a new insight on the research of joint reducers as well as other fields.

The Rotational Accuracy Characteristics of the Preloaded Hollow Roller Bearing

1981 ◽  
Vol 103 (1) ◽  
pp. 6-12 ◽  
Author(s):  
C. P. Bhateja ◽  
R. D. Pine
Keyword(s):  
Roller Bearing ◽  
Design Parameters ◽  
Annular Space ◽  
Dynamic Nature ◽  
Cyclic Pattern ◽  
Radial Bearing ◽  
Geometrical Features ◽  
Present Context ◽  
Rolling Elements ◽  
Inner Race

The rotational characteristics of the cageless, hollow roller radial bearing are investigated. The preloading of the hollow rolling elements in the annular space between the inner and the outer races in such a bearing provides a well controlled and consistent shaft rotational pattern. This pattern is determined by the dimensional and geometrical features of the rollers’ external and internal diameters and roundnesses, the outer and inner ring raceway roundnesses and the eccentricity of the inner race with respect to the shaft axis. The various patterns of shaft runout associated with these causes are identified and the sensitivity of the shaft runout to these factors is examined qualitatively and quantitively. The shaft runout in the present context is not merely the initial static offset of the shaft axis, but is a dynamic, cyclic pattern consisting of certain frequencies resulting from the geometrical features of the bearing components. The somewhat elusive, complex and dynamic nature of this apparent shaft runout makes it difficult to be measured. In addition, the importance of the need to control the circumferential clearance to a minimum is demonstrated. It is thus shown that through the proper control of the component geometry and certain design parameters, the hollow roller bearing can provide an extremely accurate bearing for precision applications.

scholarly journals Modeling and Dynamic Analysis of Spherical Roller Bearing with Localized Defects: Analytical Formulation to Calculate Defect Depth and Stiffness

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Behnam Ghalamchi ◽  
Jussi Sopanen ◽  
Aki Mikkola
Keyword(s):  
Dynamic Model ◽  
Contact Stiffness ◽  
Roller Bearing ◽  
Measurement Data ◽  
Contact Forces ◽  
Hertzian Contact ◽  
Radial Clearance ◽  
Outer Race ◽  
Rolling Elements ◽  
Localized Defects

Since spherical roller bearings can carry high load in both axial and radial direction, they are increasingly used in industrial machineries and it is becoming important to understand the dynamic behavior of SRBs, especially when they are affected by internal imperfections. This paper introduces a dynamic model for an SRB that includes an inner and outer race surface defect. The proposed model shows the behavior of the bearing as a function of defect location and size. The new dynamic model describes the contact forces between bearing rolling elements and race surfaces as nonlinear Hertzian contact deformations, taking radial clearance into account. Two defect cases were simulated: an elliptical surface on the inner and outer races. In elliptical surface concavity, it is assumed that roller-to-race-surface contact is continuous as each roller passes over the defect. Contact stiffness in the defect area varies as a function of the defect contact geometry. Compared to measurement data, the results obtained using the simulation are highly accurate.

Analysis of radial roller bearing rating life in complex loading conditions

2021 ◽  
pp. 1-27
Author(s):  
Vladimir Ivannikov ◽  
Mikhail Leontiev ◽  
Sergey Degtyarev ◽  
Valeriy Popov
Keyword(s):  
High Performance ◽  
Roller Bearing ◽  
Complex Loading ◽  
Contact Forces ◽  
Loading Conditions ◽  
Jet Engines ◽  
Inertia Effects ◽  
Internal Contact ◽  
Rolling Elements ◽  
Life Analysis

Abstract An approach for accurate life analysis of radial roller bearings in complex loading conditions is presented. It employs ISO~16281 and accounts not only for external radial loads applied to the inner ring, but also for (i) internal bearing clearance, (ii) flexibility of the bearing rings, (iii) rings out-of-roundness, (iv) inertia effects, (v) rolling elements profile and (vi) rings misalignment. In the last decades these factors have been becoming more and more important for modern high-performance jet engines, whose shafts are commonly hollow and the housing and the rings thicknesses may be of comparable magnitudes. To obtain the distribution of internal contact forces, an advanced static model of a bearing with deformable, potentially misaligned, rings is developed. The bending deformations of the rings are reproduced superimposing deformed shapes from each of the arising internal contact force applied individually. Bearing rollers are allowed to have non-cylindrical profile, its geometry is approximated by means of slices each having constant diameter. A robust numerical scheme for solving the resultant set of equations with the aid of the barrier functions method is constructed. To increase even further the accuracy of rating life analysis, distributions of the contact stresses between the roller and the ring surfaces, obtained by solving numerically the problem of non-Hertzian interaction, are added to computations. A numerical benchmark test is presented to demonstrate the applicability of the developed approach. It shows how the aforementioned factors influence the bearing contact forces and its rating life.

scholarly journals Kinematic Alignment in Cruciate Retaining Implants Improves the Biomechanical Function in Total Knee Arthroplasty during Gait and Deep Knee Bend

2019 ◽  
Vol 33 (03) ◽  
pp. 284-293 ◽  
Author(s):  
Kyoung-Tak Kang ◽  
Yong-Gon Koh ◽  
Ji Hoon Nam ◽  
Sae Kwang Kwon ◽  
Kwan Kyu Park
Keyword(s):  
Stance Phase ◽  
Lateral Collateral Ligament ◽  
Contact Stresses ◽  
Kinematic Alignment ◽  
Collateral Ligament ◽  
Cruciate Retaining ◽  
Lateral Contact ◽  
Lateral Collateral Ligaments ◽  
Total Knee ◽  
Maximum Contact

AbstractKinematic alignment (KA), which co-aligns the rotational axes of the components with three kinematic axes of the knee by aligning the components to the prearthritic joint lines, has been a recently introduced surgical technique. However, whether KA and cruciate retaining (CR) implants provide better biomechanical function during activities than mechanical alignment (MA) in posterior stabilized (PS) implants is unclear. We evaluated the biomechanical functions during the stance phase gait and deep knee bend, with a computer simulation and measured forces in the medial and lateral collateral ligaments and medial and lateral contact stresses in the polyethylene insert and patellar button. The forces on the medial collateral ligament in KA were lower than those in MA in both CR and PS TKA in the stance phase gait and deep knee bend conditions, whereas those on the lateral collateral ligament did not show any difference between the two surgical alignment techniques in the stance phase gait condition. The maximum contact stresses on the medial PE inserts in KA were lower than those in MA in both CR and PS TKA in the stance phase gait and deep knee bend conditions. However, the maximum contact stresses on the lateral PE inserts and the patellar button did not differ between MA and KA. The biomechanical function was superior in KA TKA than in MA TKA, and KA was more effective in CR TKA. This comparison could be used as a reference by surgeons to reduce the failure rates by using KA TKA instead of MA TKA.

Signature Analysis of Roller Bearing Vibrations: Lubrication Effects

1992 ◽  
Vol 206 (3) ◽  
pp. 193-202 ◽  
Author(s):  
Y-T Su ◽  
Y-T Sheen ◽  
M-H Lin
Keyword(s):  
Roller Bearing ◽  
Vibration Energy ◽  
Running Speed ◽  
Oil Film ◽  
Spacing Distribution ◽  
Surface Irregularities ◽  
Vibration Signature ◽  
Bearing Assembly ◽  
Bearing Vibration ◽  
Lubricant Viscosity

This study investigates the vibration signature of roller bearings, induced by the surface irregularities of components, under various lubricating conditions. The bearing vibration is modelled as the output of the bearing assembly which is subjected to the excitations of surface irregularities through the oil-film. The oil-film acts as a spring between the roller and race. The stiffness of oil-film under different lubricating conditions is studied from the empirical equation of minimum oil-film thickness. It is shown that the vibration spectra of a normal roller bearing may have a pattern of equal frequency spacing distribution (EFSD) whose frequency information is similar to that of a damaged bearing. Under large loading and low running speed, the vibration energy is low if the lubricant viscosity is high. On the other hand, at high running speed, the vibration energy is high with high lubricant viscosity.

Sign in / Sign up

Export Citation Format

Share Document