An Analytical Dynamic Model of a Hollow Cylindrical Roller Bearing

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Jing Liu ◽  
Yimin Shao
Keyword(s):  
Fatigue Life ◽  
Dynamic Model ◽  
Contact Stiffness ◽  
Roller Bearing ◽  
Great Influence ◽  
Radial Load ◽  
Shaft Speed ◽  
Roller Bearings ◽  
Cylindrical Roller ◽  
Analytical Dynamic

Hollow cylindrical roller bearings (HCRBs) have obtained much attention from design engineers in bearing industries since they can perform better than solid cylindrical roller bearings (SCRBs) in centrifugal forces, contact stiffness, cooling ability, fatigue life, etc. In this study, an analytical dynamic model of a lubricated HCRB is presented to analyze the influences of the radial load, the shaft speed, and the hollowness percentage of the roller on the bearing vibrations, which cannot be formulated by the methods in the reported literature. Both the support stiffness of the shaft and the roller mass are formulated in the presented dynamic model. The hollow hole in the roller is modeled as a uniform one. Numerical results show that the hollowness percentage of the roller has a great influence on the vibrations of the roller and the inner race of the HCRB. Moreover, the vibrations of the components of the HCRB are not only determined by the hollowness percentage of the roller, but also depended on the external radial load and shaft speed. Therefore, during the design process for the hollowness percentage of the roller, the influences of the radial load and the shaft speed on the vibrations of the bearing components should be considered, except for the fatigue life. The results show that this work can give a new dynamic method for analyzing the vibrations of the HCRBs. Moreover, it can give some guidance for the design method for the HCRBs.

Analysis of Fatigue of Cylindrical Roller Bearing in Printing Press

2013 ◽  
Vol 312 ◽  
pp. 25-28
Author(s):  
Ji Mei Wu ◽  
Yan Chen ◽  
Bo Gao ◽  
Tuan Yong Yi
Keyword(s):  
Fatigue Life ◽  
Roller Bearing ◽  
Flow Chart ◽  
Printing Press ◽  
Radial Clearance ◽  
Radial Load ◽  
Double Row ◽  
Rotating Speed ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

By means of considering improved Lundberg-Palmgren (L-P) fatigue life theory and rollers and other comprehensive factors, a model of fatigue life is setup for eccentric double row cylindrical roller bearing under rotation. On this basis, the calculation flow chart is given and the fatigue life is calculated. Then come to the conclusions that the fatigue life of bearing is influenced by radial load, rotating speed, radial clearance.

Axial Load Effect on Contact Fatigue Life of Cylindrical Roller Bearings

2004 ◽  
Vol 126 (2) ◽  
pp. 242-247 ◽  
Author(s):  
Wangquan (Winston) Cheng ◽  
Shan Shih ◽  
John Grace ◽  
Wenke Tu
Keyword(s):  
Fatigue Life ◽  
Axial Load ◽  
Roller Bearing ◽  
Contact Fatigue ◽  
Limit Load ◽  
Load Effect ◽  
Roller Bearings ◽  
Contact Fatigue Life ◽  
Fatigue Life Analysis ◽  
Cylindrical Roller

Besides primarily carrying radial load, cylindrical roller bearings with flanges or lips on both inner and outer raceways need also carry axial load in some applications. Because of the axial load, the equivalent dynamic load of the bearing will be increased and the bearing contact fatigue life will be decreased accordingly. The axial load effect on the roller bearing fatigue life had been studied by researchers in the past. Because of different assumptions used in their models, quite different predictions were made in their analysis. This work combines the methods used in the Fernlund-Synek and Brandlein models and studies general contact conditions such as partial contact along the roller length, partial loading zone of the bearing race, manufacturing tolerance and running-in effects on roller length, etc. New formulas for equivalent dynamic loads of the rotating and stationary races are derived. A fatigue limit load is also included in the life calculation to reflect the latest development in contact fatigue life analysis.

Investigation of the dynamic local skidding behaviour of rollers in cylindrical roller bearings

2019 ◽  
Vol 233 (4) ◽  
pp. 899-909
Author(s):  
Wenbing Tu ◽  
Ya Luo ◽  
Wennian Yu ◽  
Yinquan Yu
Keyword(s):  
Dynamic Model ◽  
Great Influence ◽  
Rolling Element Bearings ◽  
Sliding Velocity ◽  
Hertz Contact ◽  
Nonlinear Dynamic Model ◽  
Roller Bearings ◽  
Impact Forces ◽  
Rolling Element ◽  
Cylindrical Roller

Skidding has a great influence on the reliability and the life of rolling element bearings. The previous research of bearing skidding mainly focussed on the gross skidding of bearings under severe conditions. However, the local skidding of rolling element also exists and cannot be ignored when bearing normally runs at steady state. In this paper, considering the discontinuous contact between the roller and the cage, the Hertz contact between the roller and races, lubrication, centrifugal effects and the cage pocket clearance, a nonlinear dynamic model is established to investigate the local skidding behaviour of a roller in cylindrical roller bearings. The equations of the dynamic model are solved by the fourth-order Runge–Kutta algorithm and verified by comparing simulation results with the published experimental data. The results show that the local skidding of the roller still noticeably exists in bearings even when the gross skidding can be ignored, especially on the inner raceway. The local skidding at the entry of the loaded zone may cause the smearing on the raceway surface. However, it can be found that the probability of the local skidding of the roller will be decreased by increasing radial load and reducing the bearing rotational speed. The cage pocket clearance would induce violent fluctuations on the roller rotational angular velocity as well as on the sliding velocity. Furthermore, it can generate extraordinary impact forces between the rollers and the cage. Thus, the cage pocket clearance should be carefully considered in the design of bearings.

scholarly journals Lubrication and Fatigue Life Evaluation of High-Speed Cylindrical Roller Bearing under Misalignment

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Hongyu Duan ◽  
Jiawei Song ◽  
Zhijian Wang
Keyword(s):  
Fatigue Life ◽  
High Speed ◽  
Roller Bearing ◽  
Coupled Model ◽  
Roller Bearings ◽  
Life Model ◽  
Fatigue Life Evaluation ◽  
Roller Profile ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

This paper developed a coupled model, incorporating the quasistatic model, fatigue life model, and mixed lubrication model, to investigate the effect of misalignment angle on high-speed cylindrical roller bearings. The model is verified by comparing with the published literature results. Then, a parametric analysis is carried out. The results show that as the misalignment increases, the load distribution is basically unchanged, but the fatigue life of the roller bearing decreases due to the variation of contact pressure, and the skewing moment of single roller contact pair increases. Furthermore, the optimal design of roller profile needs to consider the effect of lubrication in order to improve the fatigue life of roller bearings. In general, the optimal crown drop is too small according to the design from the slicing technique.

Fatigue life of cylindrical roller bearings

2016 ◽  
Vol 231 (5) ◽  
pp. 623-636 ◽  
Author(s):  
Van-Canh Tong ◽  
Sun-Woong Kwon ◽  
Seong-Wook Hong
Keyword(s):  
Fatigue Life ◽  
Roller Bearing ◽  
Radial Clearance ◽  
Angular Misalignment ◽  
Error Sources ◽  
Roller Bearings ◽  
Fatigue Life Analysis ◽  
Inertial Loading ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

This paper dealt with the fatigue life of cylindrical roller bearings with several significant error sources that may occur during installations. A four degree-of-freedom quasi-static model for cylindrical roller bearings was developed, which took into account potential error sources such as angular misalignment, axial offset, and radial clearance, together with inertial loading by rotational speed and induced moment loads. A 3D contact model was employed to provide contact pressure distributions in rolling elements. The fatigue life of a cylindrical roller bearing was analyzed as a function of angular misalignment under various loading conditions. Then, the fatigue life analysis was extended to the combined effects of radial clearance, axial offset, and the number of rollers, along with angular misalignment. The computational results showed the significance of each error source on fatigue life. They further showed that cylindrical roller bearing fatigue life maximized when the radial clearances were slightly negative, and that it increased almost linearly with the number of rollers.

scholarly journals Study on Radial Stiffness of Contact Pair of Logarithmic Modified Tapered Roller Bearing

2020 ◽  
Author(s):  
Shimin Luo ◽  
Junyi Wang
Keyword(s):  
Contact Stiffness ◽  
Roller Bearing ◽  
Great Influence ◽  
Contact Pair ◽  
Radial Load ◽  
Tapered Roller Bearing ◽  
Oil Film ◽  
Radial Stiffness ◽  
Calculation Results ◽  
Tapered Roller

Based on Hertz elastic contact theory, elastohydrodynamic lubrication theory, the equivalent radial stiffness model of roller raceway contact pair of logarithmic modified tapered roller bearing is derived under the consideration of oil film stiffness. The calculation results show that the equivalent radial contact stiffness increases with the increase of contact load, increases linearly with the increase of effective contact length of roller, and changes little with the increase of modification f1. When the radial load is small, the oil film has a great influence on the equivalent radial stiffness, which decreases gradually with the increase of the radial load.

scholarly journals Comparison of planetary bearing load-sharing characteristics in wind turbine gearboxes

2018 ◽  
Vol 3 (2) ◽  
pp. 947-960 ◽  
Author(s):  
Jonathan Keller ◽  
Yi Guo ◽  
Zhiwei Zhang ◽  
Doug Lucas
Keyword(s):  
Fatigue Life ◽  
Wind Turbine ◽  
Load Sharing ◽  
Position Error ◽  
Bearing Clearance ◽  
Roller Bearings ◽  
Bearing Load ◽  
Tapered Roller ◽  
Tapered Roller Bearings ◽  
Cylindrical Roller

Abstract. In this paper, the planetary load-sharing behavior and fatigue life of different wind turbine gearboxes when subjected to rotor moments are examined. Two planetary bearing designs are compared – one design using cylindrical roller bearings with clearance and the other design using preloaded tapered roller bearings to support both the carrier and planet gears. Each design was developed and integrated into a 750 kW dynamometer tests, the loads on each planet bearing row were measured and compared to finite-element models. Bearing loads were not equally shared between the set of cylindrical roller bearings supporting the planets even in pure torque conditions, with one bearing supporting up to 46 % more load than expected. A significant improvement in planetary bearing load sharing was demonstrated in the gearbox with preloaded tapered roller bearings with maximum loads 20 % lower than the gearbox with cylindrical roller bearings. Bearing life was calculated with a representative duty cycle measured from field tests. The predicted fatigue life of the eight combined planet and carrier bearings for the gearbox with preloaded tapered roller bearings is 3.5 times greater than for the gearbox with cylindrical roller bearings. The influence of other factors, such as carrier and planet bearing clearance, gravity, and tangential pin position error, is also investigated. The combined effect of gravity and carrier bearing clearance was primarily responsible for unequal load sharing. Reducing carrier bearing clearance significantly improved load sharing, while reducing planet clearance did not. Normal tangential pin position error did not impact load sharing due to the floating sun design of this three-planet gearbox.

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.

An Optimum Design of Crowned Cylindrical Roller Bearings Using Genetic Algorithms

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
K. Sunil Kumar ◽  
Rajiv Tiwari ◽  
P. V. V. N. Prasad
Keyword(s):  
Genetic Algorithms ◽  
Fatigue Life ◽  
Stress Concentration ◽  
Stress Concentrations ◽  
Rolling Bearings ◽  
Design Constraint ◽  
Roller Bearings ◽  
Edge Stress ◽  
Heavy Loads ◽  
Cylindrical Roller

The long fatigue life is the one of the most important criterion for the design of rolling bearings, however, due to complex and diverse internal geometries, each type of rolling bearings require a different design formulation. To increase the life of cylindrical roller bearings, the profile (or the crowning) of the roller plays an important role. A flat profile of the rolling element results in the edge stress concentrations at roller ends. A circular crowning of roller eliminates the edge stress concentration at the lower and moderate loads only; however, it develops edge stress concentrations at heavy loads. The logarithmic profile of the roller results in no edge stress concentration at the low, medium, and heavy loads; distribution of contact stresses is also nearly uniform along the length of the roller. A design methodology for the optimum design of cylindrical roller bearings with the logarithmic profile has been outlined. A nonlinear constrained optimization problem has been formulated for the design of cylindrical roller bearings with logarithmic profiles and is optimized by using real-coded genetic algorithms. The change in roller profile has not been accounted for explicitly in the standard definition of the dynamic capacity; hence, for the present case directly the Lundberg–Palmgren life equation has been chosen as an objective function. Design variables include four bearing geometrical parameters and the two logarithmic profile generating parameters are considered. In addition to these, another five design constraint constants are also included, which indirectly affect the fatigue life of cylindrical roller bearings. The five design constraint constants have been given bounds based on the parametric studies through initial optimization runs. The effective length of the roller is taken corresponding to the standard roller diameter, which has standard discrete dimensions. Constraint violation study has been performed to have an assessment of the effectiveness of each of the constraints. A convergence study has been carried out to ensure the global optimum point in the design. A sensitivity analysis of various geometric design parameters has been performed using the Monte Carlo simulation technique, in order to see changes in the fatigue life of the bearing. Illustrations show that the multiplier of the logarithmic profile deviation parameter has more effect on the fatigue life as compared with other geometric parameters.

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