Calculation method for comprehensive damping of ball bearings based on multigrid method

2020 ◽  
Vol 72 (7) ◽  
pp. 937-945
Author(s):  
Peng Sun ◽  
Weifang Chen ◽  
Yusu Shen ◽  
Dan Wang
Keyword(s):  
Peer Review ◽  
Calculation Method ◽  
Rotational Speed ◽  
Multigrid Method ◽  
Ball Bearing ◽  
Damping Coefficient ◽  
Radial Load ◽  
Content Type ◽  
Oil Film ◽  
Test Platform

Purpose As an important part of the rotor system, the damping coefficient of ball bearing has a great influence on the dynamic characteristics of the system. This study aims to propose a theoretical calculation method and an experimental test method to obtain the damping coefficient of ball bearing. Design/methodology/approach Based on Hertzian contact theory and elastohydrodynamic lubrication theory, the point contact oil film damping analysis model of ball bearing is established. The comprehensive damping calculation method considering external radial load, centrifugal force, ball spin, rotational speed and lubricating oil film is derived. The multigrid method is used to obtain the oil film pressure and thickness distribution in the contact zone. The variation trend of comprehensive damping with bearing radial load, rotational speed, oil film thickness and viscosity is analyzed. The test platform is designed and the influencing factors of damping are tested. Findings The validity of the model and reliability of the test device are verified by comparing the good consistency obtained in the work. The results show that the comprehensive damping of ball bearing increases with the increase of radial load and decreases with the increase of rotational speed. Originality/value At present, the existing bearing damping model can achieve approximate calculation of damping, but the factors considered in these models are not comprehensive enough. Besides, few studies exist regarding test platform of bearing damping, and a perfect test plan has not yet been formed. In this paper, the comprehensive damping calculation model of ball bearing is improved, and a complete experimental scheme is proposed to provide reference for the comprehensive damping theory and experimental research of bearing. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2019-0342/

Measurement and calculation of oil film thickness in a ball bearing

2018 ◽  
Vol 70 (8) ◽  
pp. 1500-1508 ◽  
Author(s):  
Baogang Wen ◽  
Hongjun Ren ◽  
Pengfei Dang ◽  
Xu Hao ◽  
Qingkai Han
Keyword(s):  
Film Thickness ◽  
Ball Bearing ◽  
Performance Indicator ◽  
Thickness Distribution ◽  
Content Type ◽  
Oil Film ◽  
Capacitance Method ◽  
Lubrication Condition ◽  
Series Of Experiments ◽  
External Loads

PurposeThe oil film thickness provides a key performance indicator of a ball bearing lubrication condition. This paper aims to propose an approach to calculate and measure the oil film thickness of the bearing.Design/methodology/approachOn a specially designed test rig, measurement of the capacitance is used to monitor the oil film thickness of ball bearing. A corrected film thickness formula taking account of the influences of non-Newtonian shear thinning and thermal is introduced to predict the oil film thickness of ball bearing. And then the film thickness distribution and the corresponding capacitances are calculated.FindingsMeasurement and calculation of oil film thickness in a ball bearing are carried out under various rotating speeds and external loads. By comparing the calculated capacitances with measured results, it can be concluded that the calculated results obtained by the amended film thickness formula are much closer to the test findings than the classical computed values according to Hamrock–Dowson.Originality/valueA new corrected film thickness formula is introduced in predicting oil film thickness of ball bearing and verified by the series of experiments according to capacitance method.

A thermal EHL investigation for size effect of finite line contact on bush-pin hinge pairs in industrial chains

2020 ◽  
Vol 72 (5) ◽  
pp. 695-701
Author(s):  
Mingyu Zhang ◽  
Jing Wang ◽  
Peiran Yang ◽  
Zhaohua Shang ◽  
Yi Liu ◽  
...  
Keyword(s):  
Film Thickness ◽  
Peer Review ◽  
Contact Zone ◽  
Line Contact ◽  
Equivalent Radius ◽  
Content Type ◽  
Oil Film ◽  
Finite Line Contact ◽  
Finite Line ◽  
Thermal Ehl

Purpose This paper aims to study the influence of the dimension change of bush-pin on the pressure, oil film thickness, temperature rise and traction coefficient in contact zone by using a thermal elastohydrodynamic lubrication (EHL) model for finite line contact. Concretely, the effects of the equivalent curvature radius of the bush and the pin, and the length of the bush are investigated. Design/methodology/approach In this paper, the contact between the bush and pin is simplified as finite line contact. The lubrication state is studied by numerical simulation using steady-state line contact thermal EHL. A constitutive equation Ree–Eyring fluid is used in the calculations. Findings It is found that by selecting an optimal equivalent radius of curvature and prolonging the bush length can improve the lubrication state effectively. Originality/value Under specific working conditions, there exists an optimal equivalent radius to maximize the minimum oil film thickness in the contact zone. The increase of generatrix length will weaken the stress concentration effect in the rounded corner area at both ends of the bush, which can improve the wear resistance of chain. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0448.

An adjustable oil film thickness test rig for detecting lubrication characteristics of slipper/swash-pair in piston pumps

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Haiji Wang ◽  
Guanglin Shi
Keyword(s):  
Film Thickness ◽  
Peer Review ◽  
Relative Error ◽  
Mathematical Analysis ◽  
Test Rig ◽  
Content Type ◽  
Oil Film ◽  
Displacement Sensors ◽  
Measuring Machine ◽  
Lubrication Characteristics

Purpose The purpose of this paper is to propose an adjustable oil film thickness test rig for detecting lubrication characteristics of the slipper. The mathematical analysis of lubrication is introduced. Based on the results from the test rig, the results comparison from test rig and mathematical analysis is carried out. Design/methodology/approach This paper introduces a mechanism which can adjust the oil film thickness between the slipper and swash-plate. Feasibility is ensured, and the accuracy of test rig is guaranteed by the three-coordinate measuring machine. Three displacement sensors show the oil film thickness and its shape. The reacting force and torque resulting from oil film can be achieved by three S-type force sensors and a torque sensor, respectively. Findings The relative error of the reacting force is small. The relative error reduces and is acceptable when the deformation of retainer is taken into account. The thickness and tilt angle of oil film have less effect on the reacting force. However, they are significantly impact on torque. Originality/value The test rig proposed in this paper is able to adjust the oil film thickness, which is used to detecting the lubrication characteristics in pump design. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2020-0166/

Kinematic investigation and fatigue life analysis of angular contact ball bearing in wide speed range based on raceway friction

2020 ◽  
Vol 72 (7) ◽  
pp. 845-850
Author(s):  
Yue Liu
Keyword(s):  
Fatigue Life ◽  
Peer Review ◽  
High Speed ◽  
Ball Bearing ◽  
Operating Conditions ◽  
Angular Contact Ball Bearing ◽  
Content Type ◽  
Speed Range ◽  
Uniform Model ◽  
Wide Speed Range

Purpose The purpose of this paper is to clarify the relationship between fatigue life and kinematics of angular contact ball bearing. It proposes a new modeling method of spin to roll ratio based on raceway friction, which is more accurate than the traditional raceway control theory. Design/methodology/approach The uniform model of spin to roll ratio based on raceway friction in a wide speed range is proposed using quasi-statics method, which considers centrifugal force, gyroscopic moment, friction force of raceway and other influencing factors. The accuracy is considerably improved compared with the static model without increasing too much computation. Findings A uniform model for spin to roll ratio of angular contact ball bearing based on raceway friction is established, and quite different relationships between fatigue life and speed under two operating conditions are found. Research limitations/implications The conclusion of this paper is based on the bearing basic fatigue life calculation theory provided by ISO/TS 16281; however, the accuracy of theory needs to be further verified. Practical implications This paper provides guidance for applying angular contact ball bearing, especially at a high speed. Originality/value This paper reveals the changing trend of fatigue life of angular contact ball bearing with the speed under different loads. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0030

Effect of two-phase flow on transmission torque of oil film at high rotational speeds

2018 ◽  
Vol 70 (8) ◽  
pp. 1367-1373 ◽  
Author(s):  
Fangwei Xie ◽  
Xudong Zheng ◽  
Yaowen Tong ◽  
Bing Zhang ◽  
Xinjian Guo ◽  
...  
Keyword(s):  
Flow Regime ◽  
Rotational Speed ◽  
Two Phase Flow ◽  
Fluid Model ◽  
Flow Region ◽  
Phase Flow ◽  
Field Variation ◽  
Two Phase ◽  
Content Type ◽  
Oil Film

Purpose The purpose of this paper is to study the working characteristics of hydro-viscous clutch at high rotational speeds and obtain the trend of flow field variation of oil film. Design/methodology/approach The FLUENT simulation model of the oil film between the friction disks is built. The effect of variation of working parameters such as input rotational speed, oil flow rate and film thickness on two-phase flow regime and transmission torque is studied by using the volume of fluid model. Findings The results show that the higher the rotational speed, the severer the cavitation is. In addition, the two-phase flow region makes the coverage of oil film over the friction pairs’ surface reduce, which results in a decrease in transmission torque for the hydro-viscous clutch. Originality/value These simulation results are of interest for the study of hydro-viscous drive and its applications. This study can also provide a theoretical basis for power transmission mechanism of oil film by considering the existence of a two-phase flow regime consisting of oil and air.

On the dynamic characteristics of ball bearing with cage broken

2020 ◽  
Vol 72 (7) ◽  
pp. 881-886
Author(s):  
Hui Li ◽  
Heng Liu ◽  
Yi Liu ◽  
Shemiao Qi ◽  
Fengtao Wang
Keyword(s):  
Peer Review ◽  
Dynamic Characteristics ◽  
Ball Bearing ◽  
Dynamic Modelling ◽  
Interaction Force ◽  
High Amplitude ◽  
Fault Identification ◽  
Dynamic Simulations ◽  
Content Type ◽  
Collision Force

Purpose The purpose of this study is to investigate the dynamic behavior of the ball bearing with cage broken. Design/methodology/approach By analyzing the complicated relationship and interactions among the ball bearing elements, the dynamic modelling of the ball bearing with broken cage was established, and the dynamic simulations were conducted by solving the ball bearing dynamic equations using varying-step Runge–Kutta integration. Findings The computational results show that there is considerable distinguishment in the dynamic characteristics between the normal cage and the broken cage of the bears. The broken cage makes the trajectory of the cage erratic, and the vibration amplitude is much bigger than that of the normal cage, which makes the motion of the cage unstable. When one of the cage lintels breaks up, the two adjacent balls will collide with each other; what is worse, this may make the balls crush because of the high amplitude of the collision force. The broken cage makes the cage-race interaction force much larger than that of the normal cage, which could promote the guiding ring and quicken the cage wear-failure. Originality/value This study can provide important ideas for the fault identification of the ball bearing with cage broken. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0042/

Influence of rotational speed of a heavy-duty hydrostatic turret on bearing performance under tilt

2019 ◽  
Vol 72 (5) ◽  
pp. 575-579
Author(s):  
Zhifeng Liu ◽  
Junyuan Guo ◽  
Yumo Wang ◽  
Dong Xiangmin ◽  
Yue Wu ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Rotational Speed ◽  
Design Methodology ◽  
Reynolds Equation ◽  
Heavy Duty ◽  
Film Stability ◽  
Content Type ◽  
Oil Film ◽  
Tilt Stability ◽  
The Stability

Purpose This paper aims to propose a method for finding the maximum rotational speed of an inclined turntable at which the stability of the bearing oil film is maintained. Design/methodology/approach The finite difference method was used to solve the Reynolds equation. Variation of bearing capacity of a tilted hydrostatic turret over time was determined. The combined effect of tilt and rotational speed of the turret on the oil film stability was also analyzed. Findings When the turntable is operated at low speeds with only small angle of tilt, stability of the oil film is maintained. At lower rotational speeds, a smaller angle of tilt improves the bearing capacity and ensures stability of the oil film. Whereas, higher rotational speeds can have a considerable influence on the bearing capacity. Originality/value The results demonstrate that the inclination or tilt of the turntable significantly affects the stability of the oil film.

Matching the relationship between rotational speed and load-carrying capacity on high-speed and heavy-load hydrostatic thrust bearing

2018 ◽  
Vol 70 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Xiao-dong Yu ◽  
Lei Geng ◽  
Xiao-jun Zheng ◽  
Zi-xuan Wang ◽  
Xiao-gang Wu
Keyword(s):  
Carrying Capacity ◽  
Rotational Speed ◽  
Thrust Bearing ◽  
Lubricating Oil ◽  
Load Carrying Capacity ◽  
Average Pressure ◽  
Content Type ◽  
Oil Film ◽  
Hydrostatic Bearing ◽  
Load Carrying

Purpose Rotational speed and load-carrying capacity are two mutual coupling factors which affect high precision and stable operation of a hydrostatic thrust bearing. The purpose of this paper is to study reasonable matching relationship between the rotational speed and the load-carrying capacity. Design/methodology/approach A mathematical model of relationship between the rotational speed and the load-carrying capacity of the hydrostatic bearing with double-rectangle recess is set up on the basis of the tribology theory and the lubrication theory, and the load and rotational speed characteristics of an oil film temperature field and a pressure field in the hydrostatic bearing are analyzed, reasonable matching relationship between the rotational speed and the load-carrying capacity is deduced and a verification experiment is conducted. Findings By increasing the rotational speed, the oil film temperature increases, the average pressure decreases and the load-carrying capacity decreases. By increasing the load-carrying capacity, the oil film temperature and the average pressure increases and the rotational speed decreases; corresponding certain reasonable matching values are available. Originality/value The load-carrying capacity can be increased and the rotational speed improved by means of reducing the friction area of the oil recess by using low-viscosity lubricating oil and adding more oil film clearance; but, the stiffness of the hydrostatic bearing decreases.

Effect of structural parameters of oil groove on hydro-viscous drive torque with variable rotational speed

2018 ◽  
Vol 70 (9) ◽  
pp. 1745-1756
Author(s):  
Fangwei Xie ◽  
Xinjian Guo ◽  
Diancheng Wu ◽  
Bing Zhang ◽  
Xudong Zheng ◽  
...  
Keyword(s):  
Rotational Speed ◽  
Structural Parameters ◽  
Effective Area ◽  
Outer Diameter ◽  
Content Type ◽  
Oil Film ◽  
Oil Distribution ◽  
Groove Structure ◽  
Friction Plate ◽  
First Time

Purpose In this paper, a kind of an oil groove structure which could improve the transmission torque of an oil film was designed, i.e. the width and depth of oil groove gradually decrease with the increase in the radius. Design/methodology/approach Effects of the structural parameters of the oil groove on the hydro-viscous drive (HVD) characteristics with variable rotational speed were investigated by means of numerical calculation. Findings Research results show that with the decrease of the width and depth of the oil groove at the outer diameter, transmission torque increases, while the temperature is almost unchanged. Keeping the effective area unchanged, comparing the transmitted torque under the oil groove angle θ2 = 0.5° and θ2 = 4.5°, the former was almost 200 per cent of the latter; the torque transmitted with h2 = 0.05 mm was almost 150 per cent of that with h2 = 0.2 mm. Originality/value In this paper, the authors analyze the friction surface of the friction plate between the oil groove, oil distribution and oil film transfer torque from the oil groove structure parameters and found methods to improve the transmission torque. For the first time, the influence of the structural parameters of oil groove on the characteristics of HVD was studied under the condition of variable rotational speed, and a better method to improve the transmission torque was proposed.

Computational-experimental research of the stiffness of high-speed spindles

2020 ◽  
pp. 33-39
Author(s):  
I.A. Zverev
Keyword(s):  
Elastic Deformation ◽  
Experimental Research ◽  
Rotational Speed ◽  
High Speed ◽  
Ball Bearing ◽  
Deformation Model ◽  
Ball Bearings ◽  
Radial Load ◽  
Angular Contact Ball Bearing ◽  
Spindle Unit

The stiffness indices of high-speed spindle units on angular contact ball bearings at high rotational speeds are investigated. It is found, that the spindle rotational speed, radial load, bearing temperature, type and magnitude of the preload in the bearings significantly affect the stiffness of the spindle unit. Keywords: high-speed spindle unit, angular contact ball bearing, elastic-deformation model. [email protected]

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