Analysis of bearing failures in a typical high-power marine gearbox

2018 ◽  
Vol 70 (1) ◽  
pp. 33-41
Author(s):  
Haigang Gu ◽  
Guang Feng ◽  
Yonggang Lin ◽  
Chaozhu Wang

Purpose This paper aims to analyze fatigue failures of a typical marine gearbox under harsh ocean conditions, and these failures are reasonably attributed to the bearing fretting fatigue damages. Design/methodology/approach Two typical FAG cylindrical roller bearings mounted on this marine gearbox are particularly used for analysis, as they are most vulnerable to these failures. A series of simulations have also been conducted to verify the analysis results and failure reasons by reproducing the fretting fatigue damages for the same shaft-bearing system under the same manufacturing error conditions. Findings The analysis results indicate that manufacturing errors are the most possible reasons for the bearing failures, and these errors have more effects on the FAG cylindrical roller bearing as compared to other bearings mounted on the same shaft system. The simulations results are in good agreement with the theoretical analysis results and test results and hence validate that manufacturing errors are the dominant reasons for bearing fretting fatigue damages in this typical marine gearbox. Originality/value Fatigue failures of a typical marine gearbox. Manufacturing errors are the most possible reasons for the bearing failures. A series of simulations have been conducted to verify the analysis results and failure reasons. The simulations results are in good agreement with the theoretical analysis results and test results.

2020 ◽  
Vol 72 (7) ◽  
pp. 969-976
Author(s):  
Yanbin Liu ◽  
Zhanli Zhang

Purpose This study aims to uncover the influencing mechanism of the tilt angles of the cage pocket walls of the high-speed cylindrical roller bearing on the bearing skidding. Design/methodology/approach A novel cylindrical roller bearing with the beveled cage pockets was proposed. Using the Hertz contact theory and the elastohydrodynamic and hydrodynamic lubrication formulas, the contact models of the bearing were built. Using the multibody kinematics and the Newton–Euler dynamics theory, a dynamics model of the bearing was established. Using the Runge–Kutta integration method, the dynamics simulations and analysis of the bearing were performed. Findings The simulation results show that the effects of the tilt angles of the front and rear walls of the pocket on the bearing skidding are remarkable. Under a 5° tilt angle of the front wall of the pocket and a 10° tilt angle of the rear wall, the bearing skidding can be effectively decreased in the rotational speed range of 10,000-70,000 r/min. Originality/value In this paper, a novel cylindrical roller bearing with the beveled cage pockets was proposed; a dynamics model of the bearing was established; the influence mechanism of the tilt angles of the front and rear walls of the pocket on the bearing skidding was investigated, which can provide fundamental theory basis for optimizing the pocket. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0035/


2011 ◽  
Vol 20 (8) ◽  
pp. 1217-1242 ◽  
Author(s):  
K. B. Katnam ◽  
A. D. Crocombe ◽  
H. Sugiman ◽  
H. Khoramishad ◽  
I. A. Ashcroft

Advanced structural adhesives are now an important joining technique in automobile and aerospace applications. The perceived uncertainty in the long-term structural performance of bonded members when subjected to static/fatigue loads in aggressive environments is probably restricting an even more widespread use of this joining technology. In this article, the effect of moisture on the static and fatigue resistances of adhesively bonded laminate joints was investigated. Experimental tests were performed on both aged and unaged adhesively bonded laminate joints for static and fatigue responses. Further, using a cohesive zone approach for the adhesive bondlines, a combined diffusion–stress analysis was developed to predict the progressive damage observed in the joints tested experimentally. The numerical predictions were found to be in good agreement with the experimental test results.


Author(s):  
Franco Concli ◽  
Christian Thomas Schaefer ◽  
Christof Bohnert

Efficiency improvement is the new challenge in all fields of design. In this scenario the reduction of power losses is becoming more and more a main concern also in the design of power transmissions. Appropriate models to predict power losses are therefore from the earliest stages of the design phase. The aim of the project is to carry on lubrication simulations of several variants of a cylindrical-roller-bearing to understand the lubricant distribution and the related churning power losses. Several strategies to reduce the computational effort have been used. Among them the sectorial symmetry and three innovative meshing strategies (purely analytical with and without interfaces and analytical/subtractive) that have been implemented in the OpenFOAM® environment. The results of the different approaches were compared among them and with experimental observations showing good agreement and reasonable savings in terms of computational effort.


2015 ◽  
Vol 67 (5) ◽  
pp. 498-508 ◽  
Author(s):  
Li Cui ◽  
Yafei He

Purpose – The purpose of this paper is to find a new logarithmic profile model of cylindrical roller bearing, which is expected to avoid edge effect and allow a straight portion on the roller considering uniform pressure distribution and easier manufacturing. Design/methodology/approach – A new logarithmic cylindrical roller profile model using three parameters is proposed. Contact model between roller and rings and quasi-static model of roller bearing are given to obtain contact pressure distribution and solved by multi-grid and Newton–Raphson method. Optimization of modified reference rating life model of the roller bearing is proposed by using genetic algorithms. Findings – Under heavy load or tilting moment conditions, modified reference rating life of cylindrical roller bearing may increase greatly by optimization of three design parameters using the new logarithmic profile model. Originality/value – The results of the present paper could aid in the design of logarithmic profile of cylindrical roller bearing and increase fatigue life of cylindrical roller bearing.


2018 ◽  
Vol 70 (9) ◽  
pp. 1580-1589 ◽  
Author(s):  
Yongcun Cui ◽  
Sier Deng ◽  
Yanguang Ni ◽  
Guoding Chen

Purpose The purpose of this study is to investigate the effect of roller dynamic unbalance on cage stress. Design/methodology/approach Considering the impact of roller dynamic unbalance, the dynamic analysis model of high-speed cylindrical roller bearing is established. And then the results of dynamic model are used as the boundary conditions for the finite element analysis model of roller and cage to obtain the cage stress. Findings Roller dynamic unbalance affects the contact status between roller and cage pocket and causes the overall increase in cage stress. The most significant impact on cage stress is roller dynamic unbalance in angular direction of roller axis, followed by radial and axial directions. Smaller radial clearance of bearing and a reasonable range of pocket clearance are beneficial to reduce the impact of roller dynamic unbalance on cage stress; the larger cage guide clearance is a disadvantage to decrease cage stress. The impact of roller dynamic unbalance on cage stress under high-speed condition is greater than that in low-speed conditions. Originality/value The research can provide some theoretical guidance for the design and manufacture of bearing in high-speed cylindrical roller bearing.


2021 ◽  
Author(s):  
Yongjian Yu ◽  
Jishun Li ◽  
Yujun Xue

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.


Author(s):  
R Waring ◽  
J Hall ◽  
K Pullen ◽  
M R Etemad

A theoretical analysis of magnetic couplers is recounted, leading to the design and manufacture of prototype disc type magnetic couplers. Design and development of experimental test rigs are also given. Test results are presented and compared with theoretical calculations. This shows very good agreement. The exception to the rule was the case of axial load measurements, which were not accurately evaluated by the computations. The geometries tested here showed the optimum design to consist of rotors with eight poles, magnet thickness of 10 mm and a filling factor of about 0.7.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Risheng Long ◽  
Chao Zhao ◽  
Zhihao Jin ◽  
Yimin Zhang ◽  
Zhen Pan ◽  
...  

Purpose The purpose of this paper is to reveal the friction and wear performance of grooves textured cylindrical roller thrust bearings with different groove dimensions under starved lubrication. Design/methodology/approach The groove dimensions include: width of grooves (WOG, 50 µm, 100 µm and 150 µm), depth of grooves (DPOG, 7 µm, 11 µm and 15 µm) as well as groove deflection angle (GDA, 45°). A fiber laser marking system was used to prepare groove patterns on the raceways of shaft washers. The friction and wear properties of grooves textured bearings were researched through a vertical universal wear test rig using a customized roller bearing tribo-pair under starved lubrication. Static finite element analyses were conducted to reveal their surface stresses. Through the comprehensive comparison and analyses, the influence mechanism of grooves on the tribological behavior of cylindrical roller thrust bearings was proposed and discussed. Findings When grooves textured bearings run under starved lubrication, their average coefficients of friction (COFs) and wear losses are all significantly reduced and much lower than those of smooth group. The influence of DPOG on the COF curves is significant, while the influence of WOG on the COF curves is a little weak. The influence of groove dimensions on the surface stresses of grooves textured bearings is weak, whether the WOG or DPOG. In this work, when the WOG is 100 µm and the DPOG is 15 µm, its average COF and wear loss are both the lowest, 0.0066 and 0.61 mg, respectively. Compared with the data of smooth group, its friction coefficient is reduced by 75.3% and its mass loss is reduced by 95.8%, showing a significant improvement in this condition. Originality/value This work can provide a valuable reference for the raceway design and reliability optimization of rolling element bearings.


Author(s):  
Kunihiro Ogihara

The instability analysis on vibration of radial gate has been done in 1999 under the research project In JPGA (Japan penstock and water gate association) and also the model test of gate vibration has been preceded. The almost theoretical results have been satisfied of the model test results, but there is one point not to be able to explain the relation of natural frequency of gate support system. The instable condition is given by the forth power of frequency of gate system in model test, and the fact that the region of instable becomes smaller as the gate opening larger, is same as the results of theoretical analysis. In this paper, author develop the new approach which is considering the pressure change by stopping the water flow same as water hummer in pipe line. And the unstable analysis on vibration equation of radial gate motion has been done and gotten good agreement on model test results.


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