Long Wang, Fengtao Wang, Linkai Niu, Xin Li, Zihao Wang and Shuping Yan
The purpose of this paper is to combine triboelectric nanogeneration technology with ball bearing structure to achieve energy collection and fault monitoring.
Abstract
Purpose
The purpose of this paper is to combine triboelectric nanogeneration technology with ball bearing structure to achieve energy collection and fault monitoring.
Design/methodology/approach
In this paper, according to the rotation mode of ball bearings, the freestanding mode of triboelectric nanogeneration is selected to design and manufacture a novel triboelectric nanogeneration device Rolling Ball Triboelectric Nanogenerator (RB-TENG) which combines rotary energy collection with ball bearing fault self-sensing.
Findings
The 10,000s continuous operation experiment of the RB-TENG is carried out to verify its robustness. The accurate feedback relationship between the RB-TENG and rotation velocity can be demonstrated by the fitting comparison between the theoretical and experimental electrical signal periods at a certain time. By comparing the output electrical signals of the normal RB-TENG and the rotor spalling RB-TENG and polytetrafluoroethylene (PTFE) balls with different degrees of wear at 500 r/min, it can be concluded that the RB-TENG has an ideal monitoring effect on the radial clearance distance of bearings. The spalling fault test of the RB-TENG stator inner ring and rotor outer ring is carried out.
Originality/value
Through coupling experiments of rotor spalling fault of the RB-TENG and PTFE balls fault with different degrees of wear, it can be seen that when rotor spalling fault occurs, balls wear has a greater impact on the normal operation of the RB-TENG, and it is easier to identify. The fault self-sensing ability of the RB-TENG can be obtained, which is expected to provide an effective scheme for monitoring the radial wear clearance distance of ball bearings.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2024-0295/
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Jianping Wang, Haifeng Ran, Peng Dai, Shuping Yan, Xingjia Yao, Fengtao Wang and Guizhong Zuo
Herringbone groove thrust bearings are typically used in high-speed, light-load applications, such as spindle motors for hard disk drives. In the past researches, the effect of…
Abstract
Purpose
Herringbone groove thrust bearings are typically used in high-speed, light-load applications, such as spindle motors for hard disk drives. In the past researches, the effect of shaft misalignment was little considered. This study aims to reveal effects of shaft misalignment on the microscopic flow regime in the water-lubricated herringbone groove thrust bearing.
Design/methodology/approach
The liquid film in a thrust herringbone groove bearing was investigated by computational fluid dynamics. The effects of micro-grooves on the flow field were carefully explored. Two-dimensional liquid films at four different sites were examined for obtaining the rich flow field properties.
Findings
The distributions of pressure, temperature and water vapor volume fraction were obtained, the micro hydrodynamic effects were formed by the herringbone grooves and the effects of the shaft misalignment on lubrication and sealing performance could be found.
Originality/value
The influence of misalignment on the herringbone groove thrust bearing performance was investigated in detail. The obtained results could give the reference guideline for the bearing design.
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Hui Li, Heng Liu, Hao Li, Shemiao Qi, Yi Liu and Fengtao Wang
The purpose of this paper is to investigate the effect of the cage-pocket wear on the dynamic behavior of the ball bearing.
Abstract
Purpose
The purpose of this paper is to investigate the effect of the cage-pocket wear on the dynamic behavior of the ball bearing.
Design/methodology/approach
Through analyzing the complicated relationship and interactions among the ball bearing elements, the dynamic modeling of the ball bearing was established considering the gravity, drag force from the oil, hydrodynamic effect on the cage and the dynamic simulations with different amounts of the cage-pocket wear loss of the ball bearing (BPWL) were obtained by solving the ball bearing dynamic equations using Runge–Kutta method.
Findings
The results show that the trajectory of the cage’s centroid presents two vibration modes with different amplitudes. In addition, those two different forms of trajectory of different amplitudes emerge alternatively with BPWL increase moreover the diameter of the trajectory decrease significantly with the BPWL increasing, which is consistent with the experimental result and last BPWL has lightly effect on the average skidding ratio of the cage, however, the BPWL would produce significant effects on the fluctuation of the skidding ratio, which can directly reflect the stability of motion to a certain extent.
Originality/value
Practice shows that the bearing failure resulting from the cage accounts for 25 per cent of the total failure of the rolling bearings. However, few discussions about how the wear of the cage-pocket would influence the dynamic characteristics of the cage. This study can provide important ideas for the design of bearing cage-pocket size and the fault identification of the ball bearing to decrease the failure rate caused by the cage.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2019-0535/
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Hui Li, Heng Liu, Yi Liu, Shemiao Qi and Fengtao Wang
The purpose of this study is to investigate the dynamic behavior of the ball bearing with cage broken.
Abstract
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/
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Hao Xin, FengTao Liu and ZiXiang Wei
This paper proposes that the trade-off between medical benefits and privacy concerns among mHealth users extends to their disclosure intentions, manifested as individuals…
Abstract
Purpose
This paper proposes that the trade-off between medical benefits and privacy concerns among mHealth users extends to their disclosure intentions, manifested as individuals simultaneously holding intentions to tend to disclose in the near future and to reduce disclosure in the distant future. Consequently, this paper aims to explore the privacy decision-making process of mHealth users from the perspective of a dual trade-off.
Design/methodology/approach
This paper constructs the model using the privacy calculus theory and the antecedent-privacy concern-outcome framework. It employs the construal level theory to evaluate the impact of privacy calculus on two types of disclosure intentions. The study empirically tests the model using a data sample of 386 mHealth users.
Findings
The results indicate that perceived benefits positively affect both near-future and distant-future disclosure intentions. In contrast, perceived risks just negatively affect distant-future disclosure intention. Additionally, perceived benefits, near-future and distant-future disclosure intentions positively affect disclosure behavior. The findings also reveal that privacy management perception positively affects perceived benefits. Personalized services and privacy invasion experience positively affect perceived benefits and risks, while trust negatively affects perceived risks.
Originality/value
This paper considers the trade-off in the privacy calculus phase as the first trade-off. On this basis, this trade-off will extend to the disclosure intention. The individuals’ two times of trade-offs between privacy concerns and medical benefits constitute the dual trade-off perspective. This paper first uses this perspective to explore the privacy decision-making process of mHealth users. This paper employs the construal level theory to effectively evaluate the impact of privacy calculus on both disclosure intentions in mHealth, extending the theory’s applicability. Moreover, we introduce antecedents of privacy calculus from the perspectives of platform, society, and individuals, enhancing the study’s realism. The research findings provide a basis for mHealth platforms to better cater to users’ privacy needs.
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Yuan Pan, Fengtao Zhan, Zhifeng Lu, Yan Lin, Zhen Yang and Zheng Wang
The purpose of this paper is to set out a study of a Mannich base, which was synthesized and used as an acidizing corrosion inhibitor first, and to the corrosion inhibitor…
Abstract
Purpose
The purpose of this paper is to set out a study of a Mannich base, which was synthesized and used as an acidizing corrosion inhibitor first, and to the corrosion inhibitor mechanism.
Design/methodology/approach
A Mannich base, 1-phenyl-3-(1-pyrrolidinyl)-propanone (PHPP), was synthesized with acetophenone, pyrrolidine and formaldehyde at pH = approximately 2-3. The structure of PHPP was characterized by elemental analysis and Fourier transform infrared spectroscopy (FTIR). The corrosion inhibition of PHPP on N80 steel in 15 per cent hydrochloric acid (HCl) was studied by weight loss method, scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDAX), and the adsorption behavior of PHPP on the surface of N80 steel was discussed.
Findings
The results showed that the inhibition efficiency reached to 99.8 per cent and corrosion rate was 2.65 g·m-2·h-1 at 0.6 per cent of PHPP concentration in 15 per cent HCl, which indicated that PHPP presented excellent corrosion inhibition performance. The results of SEM and EDAX analysis showed that PHPP could be absorbed on the surface of N80 steel. The adsorption process of PHPP on the surface of N80 steel was chemisorption. This process was spontaneous and obeyed Langmuir adsorption isotherm.
Originality/value
It was found that PHPP presented excellent corrosion inhibition performance, and it is practicable to enhance oil production in oilfield development as a oil-well acidizing inhibitor. The study results can provide theoretical guidelines for the development of the inhibitor.
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Imran Moulaalli Jamadar and Dipakkumar Vakharia
The main objective of the paper is to explore the theoretical correlation of base oil viscosity in grease and to study the effect of grease grade on mechanical vibrations…
Abstract
Purpose
The main objective of the paper is to explore the theoretical correlation of base oil viscosity in grease and to study the effect of grease grade on mechanical vibrations associated with the damaged rolling bearings.
Design/methodology/approach
For theoretical purposes, formulation theory of dimensional analysis was implemented. Experiments were then performed on the test bearings lubricated with three different types of greases, namely, SKF LGHP2, SKF LGMT3 and SKF LGWA2.
Findings
The numerical results obtained from the theoretical model along with the results of experiments show that the vibration amplitudes of the defective bearings come down to a lower level when it is lubricated with the grease of a higher base oil viscosity.
Research limitations/implications
The promising results from the theoretical model make it usable for the practical rotating machineries applying a variety of the rolling bearings. Consequently, if the bearing is not severely damaged, its performance can be increased by lubricating it with thicker grease.
Originality/value
Despite many significant contributions in the field to detect the presence of defects, not many studies have been performed that relate the lubrication condition of the rolling bearings with the vibration response, because around 50-75% of the bearing failures are attributed to be lubrication related. Hence, there is need to develop a mathematical model that can correlate the vibration severity of the bearings with viscosity of the lubricant oil in the greases along with other design and operating parameters.