SELECTING the correct bearing for any particular application involves more than the determination of the correct type and size. It is true that the calculation of the nominal…
Abstract
SELECTING the correct bearing for any particular application involves more than the determination of the correct type and size. It is true that the calculation of the nominal working life will give an indication of the operational life before failure, but this calculation only takes into account the fatigue life of the material. If this theoretical life is to be obtained—and perhaps exceeded—then additional factors must be taken into account when initially designing the bearing arrangement. Lubrication and protection from the operating environment are two very important considerations.
Guozhen Liu, Liu Wang, Chuang Liu, Pengfei Bai, Tieming Liu, Chunping Wei and Zhang Yi
This study aims to investigate the sealing performance of reciprocating seals under the effect of rubber abrasion using ABAQUS simulation software, and to propose a prediction…
Abstract
Purpose
This study aims to investigate the sealing performance of reciprocating seals under the effect of rubber abrasion using ABAQUS simulation software, and to propose a prediction framework based on a hybrid algorithm (GA-PSO-BPNN) to predict the leakage of reciprocating seals of downhole gauging instrumentation under different working condition parameters.
Design/methodology/approach
The authors combined the UMESHMOTION user program with the improved Archard wear model to investigate reciprocating seal performance. GA and a PSO were proposed as ways to enhance the BPNN’s predictive model.
Findings
The results show that the impact of fluid pressure fluctuations on the wear of the seal lip is more pronounced during the rapid wear phase compared to the steady wear phase. Similarly, variations in compression rate have a greater impact on seal lip wear at different stages of wear. The GA-PSO-BPNN prediction model outperforms the single-prediction model in terms of prediction accuracy.
Originality/value
The authors investigated sealing performance through simulation software and propose a GA-PSO-BPNN-based fault diagnosis method for rotating machinery. To verify the accuracy of the prediction model, a reciprocating sealing test platform for gauge work cylinders is constructed.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2024-0293/
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Fuying Zhang and Yuanhao Zhang
The purpose of this paper is to study the pumping efficiency of oil seals with different surface textures at different speeds, and the influence of the rotation direction of…
Abstract
Purpose
The purpose of this paper is to study the pumping efficiency of oil seals with different surface textures at different speeds, and the influence of the rotation direction of triangular texture on the sealing performance was further analyzed.
Design/methodology/approach
Based on the theory of elastohydrodynamic lubrication and the pumping mechanism of rotary shaft seals, establishing a numerical model of mixed lubrication in oil seal sealing area. The model is coupled with the lip surface texture parameters and the two-dimensional average Reynolds equation considering the surface roughness.
Findings
The results show that the application of lip surface texture technology has obvious influence on the oil film thickness, friction torque and pumping rate of oil seal. The triangular texture has the most significant effect on the increase of pump suction rate. When the rotation direction of triangular texture is 315 degrees, the pumping rate of oil seal is the largest compared with the other seven directions.
Originality/value
The model has a comprehensive theoretical guidance for the design of new oil seal products, which provides a certain basis for the application of surface texture technology in the field of sealing in the future.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2020-0198/
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Zhang Yi, Zhang Xiaodong, Chang Xueping and Wu Qian
This paper aims to clarify the relationship between the cone bit seal failure and the down-hole drilling fluid pressure and high temperature that occur during ultra-deep well…
Abstract
Purpose
This paper aims to clarify the relationship between the cone bit seal failure and the down-hole drilling fluid pressure and high temperature that occur during ultra-deep well drilling. It proposes that the contact pressure distribution under low pressure conditions is favourable for lubrication and the seal inner wear is serious under high pressure conditions. Furthermore, the more reliable cone bit seal can be obtained using the back propagation (BP) neural network and genetic algorithm (GA) to reduce the drilling cost.
Design/methodology/approach
The wear morphologies of the seal surface were analyzed using Contour GT-K to determine the seal contact pressure distribution. Then, the influences of the drilling fluid pressure and high temperature on the metal seal interface were analyzed using finite element method. The structural parameters of the seal under high pressure were optimized based on the BP neural network and GA.
Findings
This paper proposes that the inner seal contact pressure increases rapidly with an increase in the drilling fluid pressure. The design parameters of the seal components should be adjusted reasonably to ensure that the outer contact pressure is greater than the inner contact pressure, which is advantageous for forming a lubricant film on the inner side of the seal. The uneven temperature distribution of the seal surface will further aggravate seal failure.
Originality/value
Study on the bit seal with good property is significant in drilling application, and the optimized seal can prolong the cone bit life.
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THESE notes have been prepared because it is a fact that there is no publication available to the ordinary aeroplane mechanic which gives him the essential information which will…
Abstract
THESE notes have been prepared because it is a fact that there is no publication available to the ordinary aeroplane mechanic which gives him the essential information which will guide him in the overhaul and maintenance of hydraulic equipment. There are only one or two books which even touch on the subject other than the official (and very excellent) R.A.F. publication, A.P. 1803.
THE Engineering, Marine, Welding and Nuclear Energy Exhibition opens at Olympia on April 16th and runs until April 30. It is open from 10 a.m. to 6 p.m. each day (except Sundays)…
Abstract
THE Engineering, Marine, Welding and Nuclear Energy Exhibition opens at Olympia on April 16th and runs until April 30. It is open from 10 a.m. to 6 p.m. each day (except Sundays), with the exception of April 27th, 28th, and 29th, when it remains open until 8 p.m. Price of admission is 3s. There are well over 500 stands and of these between 60 and 70 are showing products that should be of interest to most readers of Scientific Lubrication, since they concern some type of lubrication equipment. Amongst these are the following, and the illustrations reproduced here concern items which will be exhibited on the stands. Items in bold type describe new products or products being exhibited for the first time.
IT is a long time since The Life of Johnson defined man as a tool‐making animal, and the tools he used in those days were primitive when contrasted with the precise, complicated…
Abstract
IT is a long time since The Life of Johnson defined man as a tool‐making animal, and the tools he used in those days were primitive when contrasted with the precise, complicated and sophisticated ones employed today. Early tools were really evolved through centuries as necessary extensions of a man's arms. A spade gave them leverage and a longer reach.
THE invitations which some 4,000 scientists and technologists accept every year to visit the National Physical Laboratory during the two Open Days in May are equally available to…
Abstract
THE invitations which some 4,000 scientists and technologists accept every year to visit the National Physical Laboratory during the two Open Days in May are equally available to such accredited representatives of industrial concerns as care to apply for them.
INDUSTRIAL consultants are being increasingly employed both here and in the United States. It is natural that much of their work should fall within the field of work study since…
Abstract
INDUSTRIAL consultants are being increasingly employed both here and in the United States. It is natural that much of their work should fall within the field of work study since the usual reason for calling them in is to secure greater productivity. Such incursions are sometimes looked at askance by those assigned to that particular role in a company. This understandable human attitude will not be exorcised by implying that consultants are a race of infallible beings whose job is to impose superior methods on the permanent staff.
The bedrock of patient and doctor trust is under threat. Government moves to centralise patient records are putting the security of medical records at risk, which in turn is…
Abstract
The bedrock of patient and doctor trust is under threat. Government moves to centralise patient records are putting the security of medical records at risk, which in turn is jeopardising patient confidentiality. This is being felt most among those with sensitive medical records such as substance users, young people and those with mental health problems. In a scathing article, Ross Anderson exposes the government's rush to create an unwieldy database at the expense of security. He reveals a deliberate avoidance to seek patient consent and uncovers a worrying exposure of our most intimate details to exploitation by commerce, police and criminals.