scholarly journals Structures Dynamic Property Analysis of Elastic Composite Cylindrical Rolling Element

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Yao Qishui ◽  
Chen Qianxu ◽  
Yu Jianghong ◽  
Yang Wen

Elastic composite cylindrical roller bearing is a novel type of roller bearing whose rolling element is designed by innovating the rolling element structure of cylindrical roller bearings. For the purpose of investigating the dynamic properties of the rolling elements with different structural parameters and solving the modes of elastic composite cylindrical rolling element with different filling degrees, first, this study compares elastic composite cylindrical rolling element to solid cylindrical rolling element, in terms of natural frequency and vibration mode. Next, the integration time step is determined, based on the natural frequency of the vibration in the Y direction, the response of various rolling element, under impact loads, is solved. Furthermore, the laws of the energy changes and nodal displacement variations of rolling element are explored, at different filling degrees. Finally, adopting the decay method, the damping ratio of elastic composite cylindrical rolling element, under different structural parameters and external loads, is calculated. According to the results, with the increase of filling degree, the natural frequencies of various orders of elastic composite cylindrical rolling element gradually declined. The damping ratio of rolling elements decreased, as the filling degree increased, while it could be changed by adjusting the structural dimensions of rolling elements. The analysis results of this study provide some theoretical reference for studies on the parameter optimization of rolling element structures, the vibration and noise reduction of elastic composite cylindrical roller bearings.

2019 ◽  
Vol 9 (9) ◽  
pp. 1017-1024
Author(s):  
Jianghong Yu ◽  
Lei Xiang ◽  
Wen Yang ◽  
Chao Li ◽  
Yaoyao Deng ◽  
...  

Elastic composite cylindrical roller bearing is a new type of rolling bearings. Its rolling body is composed of rigid and flexible materials. In order to investigate the modal characteristics and harmonic response rules of the elastic composite cylindrical roller bearings with different structural parameters, we computed the modal solutions of a cylindrical roller bearing and the elastic composite cylindrical roller bearings with filling degrees of 40%, 50% and 65%, and determined the scope of the excitation frequency according to the computed first twelve orders of the modal frequency. On this basis, we analyzed the steady-state response under a sinusoidal alternating load as well as the vibration conditions of the elastic composite cylindrical roller bearings with different filling degrees within the excitation scope, and explored the relationship between the responses such as displacement and stress and the excitation frequency. The results showed that the natural frequencies of the elastic composite cylindrical roller bearings with filling degrees of 40% and 50% were similar to that of a solid bearing, while that of the elastic composite cylindrical roller bearings with a filling degree of 65% was relatively smaller than that of a solid bearing. The vibration modes of the bearings mainly manifested as bending and torsional deformation of the inner rings. Under the action of an excitation load, the peak responses of the bearings occurred near the fifth and sixth orders of the natural frequency. This research can provide a theoretical reference for the optimal design and engineering applications of the elastic composite cylindrical roller bearings.


Author(s):  
W. Chen ◽  
R. Mills ◽  
R. S. Dwyer-Joyce

The load applied by each rolling element on a bearing raceway controls friction, wear and service life. It is possible to infer bearing load from load cells or strain gauges on the shaft or bearing housing. However, this is not always simply and uniquely related to the real load transmitted by rolling elements directly to the raceway. Firstly, the load sharing between rolling elements in the raceway is statically indeterminate, and secondly, in a machine with non-steady loading, the load path is complex and highly transient being subject to the dynamic behaviour of the transmission system. This study describes a method to measure the load transmitted directly by a rolling element to the raceway by using the time of flight (ToF) of a reflected ultrasonic pulse. A piezoelectric sensor was permanently bonded onto the bore surface of the inner raceway of a cylindrical roller bearing. The ToF of an ultrasonic pulse from the sensor to the roller–raceway contact was measured. This ToF depends on the speed of the wave and the thickness of the raceway. The speed of an ultrasonic wave changes with the state of the stress, known as the acoustoelastic effect. The thickness of the material varies when deflection occurs as the contacting surfaces are subjected to load. In addition, the contact stiffness changes the phase of the reflected signal and in simple peak-to-peak measurement, this appears as a change in the ToF. In this work, the Hilbert transform was used to remove this contact dependent phase shift. Experiments have been performed on both a model line contact and a single row cylindrical roller bearing from the planet gear of a wind turbine epicyclic gearbox. The change in ToF under different bearing loads was recorded and used to determine the deflection of the raceway. This was then related to the bearing load using a simple elastic contact model. Measured load from the ultrasonic reflection was compared with the applied bearing load with good agreement. The technique shows promise as an effective method for load monitoring in real-world bearing applications.


1976 ◽  
Vol 18 (6) ◽  
pp. 263-270
Author(s):  
P. H. Markho ◽  
D. Dowson

The principal objective of this paper is to ascertain and quantify the cyclic movement of the centre of a shaft in a geometrically perfect, lubricated, cylindrical roller bearing exhibiting initial clearance and subjected to a light and steady load. The movement may be important in relation to the accuracy of location of shafts in roller bearings, and it is shown that a detailed consideration of the rolling element assembly predicts some interesting effects. The study also covers more conventional features of bearing performance such as lubricant film thickness and coefficient of friction, and shows the effect of squeeze to be negligible under steady bearing loads.


1973 ◽  
Vol 187 (1) ◽  
pp. 763-770 ◽  
Author(s):  
C. M. Taylor

Normally cylindrical roller bearings are employed to transmit purely radial loads. However, depending upon the configuration of lips or flanges on the rings, it is sometimes possible to carry an axial load. In certain applications, an axial load capability is essential. A significant feature in determining the performance of a cylindrical roller bearing under axial loading is the lubrication conditions existing between the lips and rolling elements. The paper describes a study of such conditions. The long-term aim of the work is to provide a basis for the design of cylindrical roller bearings to carry axial loads.


1973 ◽  
Vol 187 (1) ◽  
pp. 763-770
Author(s):  
C. M. Taylor

Normally cylindrical roller bearings are employed to transmit purely radial loads. However, depending upon the configuration of lips or flanges on the rings, it is sometimes possible to carry an axial load. In certain applications, an axial load capability is essential. A significant feature in determining the performance of a cylindrical roller bearing under axial loading is the lubrication conditions existing between the lips and rolling elements. The paper describes a study of such conditions. The long-term aim of the work is to provide a basis for the design of cylindrical roller bearings to carry axial loads.


Author(s):  
Wenjun Gao ◽  
Shuo Zhang ◽  
Xiaohang Li ◽  
Zhenxia Liu

In cylindrical roller bearings, the drag effect may be induced by the rolling element translating in a fluid environment of the bearing cavity. In this article, the computational fluid dynamics method and experimental tests are employed to analyse its flow characteristics and pressure distribution. The results indicate that the pressure difference between the windward side and the leeward side of the cylinder is raised in view of it blocking the flow field. Four whirl vortexes are formed in four outlets of two wedge-shaped areas between the front part of the cylindrical surface and adjacent walls for the cylinder of L/ D = 1.5 at Re = 4.5 × 103. Vortex shedding is found in the direction of cylinder axis at Re = 4.5 × 104. The relationship between drag coefficient and Reynolds number is illustrated, obviously higher than that of the two-dimensional cylinder in open space.


1979 ◽  
Vol 101 (3) ◽  
pp. 293-302 ◽  
Author(s):  
P. K. Gupta

An analytical formulation for the roller motion in a cylindrical roller bearing is presented in terms of the classical differential equations of motion. Roller-race interaction is analyzed in detail and the resulting normal force and moment vectors are determined. Elastohydrodynamic traction models are considered in determining the roller-race tractive forces and moments. Formulation for the roller end and race flange interaction during skewing of the roller is also considered. Roller-cage interactions are assumed to be either hydrodynamic or fully metallic. Simple relationships are used to determine the churning and drag losses.


2019 ◽  
Vol 142 (3) ◽  
Author(s):  
Andreas Fingerle ◽  
Jonas Hochrein ◽  
Michael Otto ◽  
Karsten Stahl

Abstract Planetary gearboxes are becoming more popular due to their high-power density and potentially high efficiency. When the planet bearings are internally mounted, the body of the planet gear has to be hollow. The demand for large outer diameters due to high-load requirements might result in a small planet rim thickness. Depending on the rim thickness, its rigidity may become very low. Due to the low stiffness and the special load conditions caused by the double meshing, the deformation of the planet and its bearings are unique. In this paper, the influence of rim thickness on bearing load and lifetime is examined. The analysis is performed with a finite element method (FEM) model of a planet rim with a built-in cylindrical roller bearing. With the resulting planet deformation from the FEM calculation, the load distribution on the rolling elements in the bearing and the bearing lifetime according to ISO/TS 16281:2008 has been evaluated.


Author(s):  
Andreas Fingerle ◽  
Jonas Hochrein ◽  
Michael Otto ◽  
Karsten Stahl

Abstract Planetary gearboxes are becoming more popular due to their high power density and potentially high efficiency. When the planet bearings are internally mounted, the body of the planet gear has to be hollow. The demand for large outer diameters due to high load requirements might result in a small planet rim thickness. Depending on the rim thickness, its rigidity may become very low. Due to the low stiffness and the special load conditions caused by the double meshing, the deformation of the planet and its bearings are unique. In this paper, the influence of rim thickness on bearing load and lifetime are examined. The analysis is performed with an FEM model of a planet rim with a built-in cylindrical roller bearing. With the resulting planet deformation from the FEM calculation, the load distribution on the rolling elements in the bearing and the bearing lifetime according to ISO/TS 16281:2008 have been evaluated.


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