scholarly journals Improving stamping simulation accuracy by accounting for realistic friction and lubrication conditions: Application to the door-outer of the Mercedes-Benz C-class Coupé

2016 ◽  
Vol 734 ◽  
pp. 032091 ◽  
Author(s):  
J. Hol ◽  
J.H. Wiebenga ◽  
J. Stock ◽  
J. Wied ◽  
K. Wiegand ◽  
...  
Keyword(s):  
Simulation Accuracy ◽  
Lubrication Conditions ◽  
Friction And Lubrication

scholarly journals EVOLUTION OF THERMOPHYSICAL PROBLEMS IN CONSTRUCTIONS OF VVER REACTORS MAIN CIRCULATION PUMPS

2019 ◽  
Vol 41 (3) ◽  
pp. 45-54
Author(s):  
G. I. Sharaevsky ◽  
N. М. Fialko ◽  
I. G. Sharaevsky ◽  
L. B. Zimin
Keyword(s):  
Nuclear Power ◽  
Point Of View ◽  
Monitoring Systems ◽  
Sliding Bearings ◽  
Main Circulation ◽  
Lubrication Conditions ◽  
Friction And Lubrication

Changes in the design of critical critical from the point of view of safety of the nodes of the main circulation pumps of nuclear power units and the corresponding dynamics of the accompanying thermo-hydraulic problems caused by these changes are analyzed. Attention is drawn to the insufficiently studied complex thermophysical processes occurring in tribological pairs of mechanical shaft sealing and sliding bearings, where the normal friction and lubrication conditions can latently go to pre-emergency and insufficiently controlled by existing monitoring systems technical conditions.

Experiment Study of Oil-Air Lubrication on Cooling of Turning Tools

2011 ◽  
Vol 189-193 ◽  
pp. 3187-3190 ◽  
Author(s):  
Jin Li Wang ◽  
Lin Cai ◽  
Hong Tao Zheng
Keyword(s):  
Metal Cutting ◽  
Research Work ◽  
Cutting Temperature ◽  
Cost Savings ◽  
Machining Process ◽  
Dry Cutting ◽  
Air Lubrication ◽  
Temperature Contrast ◽  
Cooling Technology ◽  
Lubrication Conditions

When lubricants are used according to special requirements, it is possible to achieve considerable cost savings. Compared to conventional coolant cooling technology used in metal cutting, oil-air lubrication increases cooling performance, avoids environmental pollution, reduces running and maintenance costs. The cutting temperature contrast experimental research was based on close to practice 45# steel in dry cutting, wet cutting and oil-air lubrication conditions. The research work concentrated on the superiority of oil-air lubrication cooling and the influence of cutting amount on temperature. The experimental results show that oil-air lubrication is more effective in reducing the cutting temperature than wet cutting or dry cutting, this paper details the cutting temperature curves at several different tests provides a basis for industrial production, improves the level of machining process and the significance was being reported.

scholarly journals Contact stiffness and damping of spiral bevel gears under transient mixed lubrication conditions

Friction ◽  
2021 ◽  
Author(s):  
Zongzheng Wang ◽  
Wei Pu ◽  
Xin Pei ◽  
Wei Cao
Keyword(s):  
Contact Stiffness ◽  
Mixed Lubrication ◽  
Asperity Contact ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Dry Contact ◽  
Spiral Bevel ◽  
Stiffness And Damping ◽  
Lubrication Conditions ◽  
Film Lubrication

AbstractExisting studies primarily focus on stiffness and damping under full-film lubrication or dry contact conditions. However, most lubricated transmission components operate in the mixed lubrication region, indicating that both the asperity contact and film lubrication exist on the rubbing surfaces. Herein, a novel method is proposed to evaluate the time-varying contact stiffness and damping of spiral bevel gears under transient mixed lubrication conditions. This method is sufficiently robust for addressing any mixed lubrication state regardless of the severity of the asperity contact. Based on this method, the transient mixed contact stiffness and damping of spiral bevel gears are investigated systematically. The results show a significant difference between the transient mixed contact stiffness and damping and the results from Hertz (dry) contact. In addition, the roughness significantly changes the contact stiffness and damping, indicating the importance of film lubrication and asperity contact. The transient mixed contact stiffness and damping change significantly along the meshing path from an engaging-in to an engaging-out point, and both of them are affected by the applied torque and rotational speed. In addition, the middle contact path is recommended because of its comprehensive high stiffness and damping, which maintained the stability of spiral bevel gear transmission.

scholarly journals Microstructure and Wear Behavior of Plasma-Sprayed TiO2–SiAlON Ceramic Coating

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1268
Author(s):  
Yun Wang ◽  
Weichao Wan ◽  
Junhong Mao ◽  
Lihui Tian ◽  
Ruitao Li
Keyword(s):  
Ceramic Coating ◽  
Wear Behavior ◽  
Rutile Phase ◽  
Atmospheric Plasma ◽  
Tio2 Anatase ◽  
Sialon Ceramic ◽  
Mating Surface ◽  
Starved Lubrication ◽  
Plasma Sprayed ◽  
Lubrication Conditions

In this study, atmospheric plasma spray was employed to deposit TiO2–SiAlON ceramic coating on 316 stainless steel. The phases and microstructure of the ceramic coating were investigated. Additionally, comparative studies on the tribological performances of the substrate and the ceramic coating, under both dry and starved lubrication conditions, were carried out. The SiAlON phase was preserved, while partial TiO2 anatase was transformed to rutile phase. The wear rate of the coating was roughly 1/3 of that of the substrate under both conditions. The wear mechanisms of the ceramic coating were surface fracture and abrasive wear in both cases, and the coating under starved lubrication underwent less abrasion. The pores in the coating served as micro-reservoirs, forming an oil layer on the mating surface, and improving tribological properties during sliding.

scholarly journals Application of Dynamically Constrained Interpolation Methodology in Simulating National-Scale Spatial Distribution of PM2.5 Concentrations in China

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 272
Author(s):  
Ning Li ◽  
Junli Xu ◽  
Xianqing Lv
Keyword(s):  
Transport Model ◽  
Ground Level ◽  
Kriging Interpolation ◽  
Model Parameters ◽  
National Scale ◽  
Constrained Interpolation ◽  
Simulation Accuracy ◽  
Interpolation Accuracy ◽  
Geographical Regions ◽  
The Right

Numerous studies have revealed that the sparse spatiotemporal distributions of ground-level PM2.5 measurements affect the accuracy of PM2.5 simulation, especially in large geographical regions. However, the high precision and stability of ground-level PM2.5 measurements make their role irreplaceable in PM2.5 simulations. This article applies a dynamically constrained interpolation methodology (DCIM) to evaluate sparse PM2.5 measurements captured at scattered monitoring sites for national-scale PM2.5 simulations and spatial distributions. The DCIM takes a PM2.5 transport model as a dynamic constraint and provides the characteristics of the spatiotemporal variations of key model parameters using the adjoint method to improve the accuracy of PM2.5 simulations. From the perspective of interpolation accuracy and effect, kriging interpolation and orthogonal polynomial fitting using Chebyshev basis functions (COPF), which have been proved to have high PM2.5 simulation accuracy, were adopted to make a comparative assessment of DCIM performance and accuracy. Results of the cross validation confirm the feasibility of the DCIM. A comparison between the final interpolated values and observations show that the DCIM is better for national-scale simulations than kriging or COPF. Furthermore, the DCIM presents smoother spatially interpolated distributions of the PM2.5 simulations with smaller simulation errors than the other two methods. Admittedly, the sparse PM2.5 measurements in a highly polluted region have a certain degree of influence on the interpolated distribution accuracy and rationality. To some extent, adding the right amount of observations can improve the effectiveness of the DCIM around existing monitoring sites. Compared with the kriging interpolation and COPF, the results show that the DCIM used in this study would be more helpful for providing reasonable information for monitoring PM2.5 pollution in China.

Measurement of roller chain wear lubricated with palm oil-based hexagonal boron nitride nanoparticles

2020 ◽  
Vol 72 (10) ◽  
pp. 1199-1204
Author(s):  
Hilmi Amiruddin ◽  
Mohd Fadzli Bin Abdollah ◽  
Muhamad Aliff Danial Mohamad Nizar
Keyword(s):  
Boron Nitride ◽  
Palm Oil ◽  
Wear Mechanism ◽  
Hexagonal Boron Nitride ◽  
Wear Performance ◽  
Content Type ◽  
Roller Chain ◽  
Resistance Torque ◽  
Torque Values ◽  
Lubrication Conditions

Purpose This study aims to introduce a novel technique which helped in quantifying the wear performance of a roller chain which was lubricated by using the palm oil-based hexagonal boron nitride (hBN) nanoparticles (nano-biolubricant). Design/methodology/approach The efficiency of the nano-biolubricant was evaluated by using a custom-made roller chain tribometer, at different resistance torque values at a constant speed and running time. Prior to the test, 2 different lubrication conditions were applied. The mass loss and elongation behaviour of a roller chain was selected as a degradation metric for monitoring the amount of the chain wear. The predominant wear mechanism of a roller chain was identified by surface morphological analysis. Findings Regardless of the lubrication conditions, the wear performance of the roller chain was significantly increased, at increasing resistance torque values. Higher wear was noted when the roller chain was lubricated using a nano-biolubricant, however, the wear curve showed a promising high chain life. The predominant wear mechanism involved is abrasive wear. Originality/value Although an increase in the elongation during running is based on the wear between the pins and roller, none of the earlier studies quantified the wear performance of a roller chain under differing lubrication conditions. Hence, for bridging the gap, this study described a new method for measuring the wear performance of the roller chain which was lubricated using the palm oil-based hBN nanoparticles or a nano-biolubricant. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2020-0061/

scholarly journals Comparison Between the Action of Nano-Oxides and Conventional EP Additives in Boundary Lubrication

Lubricants ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 54
Author(s):  
Valdicleide Silva Mello ◽  
Marinalva Ferreira Trajano ◽  
Ana Emilia Diniz Silva Guedes ◽  
Salete Martins Alves
Keyword(s):  
Friction Coefficient ◽  
Boundary Lubrication ◽  
Friction And Wear ◽  
Film Formation ◽  
Environmental Issues ◽  
Protective Film ◽  
Extreme Pressure ◽  
Extreme Pressure Additives ◽  
Environmental Requirements ◽  
Lubrication Conditions

Additives are essential in lubricant development, improving their performance by the formation of a protective film, thus reducing friction and wear. Some such additives are extreme pressure additives. However, due to environmental issues, their use has been questioned because their composition includes sulfur, chlorine, and phosphorus. Nanoparticles have been demonstrated to be a suitable substitute for those additives. This paper aims to make a comparison of the tribological performance of conventional EP additives and oxides nanoparticles (copper and zinc) under boundary lubrication conditions. The additives (nanoparticles, ZDDP, and sulfur) were added to mineral and synthetic oils. The lubricant tribological properties were analyzed in the tribometer HFRR (high frequency reciprocating rig), and during the test, the friction coefficient and percentual of film formation were measured. The wear was analyzed by scanning electron microscopy. The results showed that the conventional EP additives have a good performance owing to their anti-wear and small friction coefficient in both lubricant bases. The oxides nanoparticles, when used as additives, can reduce the friction more effectively than conventional additives, and displayed similar behavior to the extreme pressure additives. Thus, the oxide nanoparticles are more environmentally suitable, and they can replace EP additives adapting the lubricant to current environmental requirements.

Wear Behavior and Chemical Friction Modification in Binary-Additives System under Boundary-Lubrication Conditions

1981 ◽  
Vol 24 (4) ◽  
pp. 517-525 ◽  
Author(s):  
Masayuki Kagami ◽  
Masataro Yagi ◽  
Seiichiro Hironaka ◽  
Toshio Sakurai
Keyword(s):  
Boundary Lubrication ◽  
Wear Behavior ◽  
Lubrication Conditions

The Analysis on the Tribological Properties of TPU/PVC Blends under Oil Lubrication

2013 ◽  
Vol 774-776 ◽  
pp. 94-98
Author(s):  
Dao Yuan Pan ◽  
Peng Peng Wu ◽  
Zhong Xue Gao ◽  
Yu Zeng Zhang
Keyword(s):  
Working Conditions ◽  
Friction And Wear ◽  
Oil Lubrication ◽  
Wear Properties ◽  
Operation Conditions ◽  
Hydraulic Steering ◽  
Pros And Cons ◽  
Friction And Wear Properties ◽  
Lubrication Conditions ◽  
Better Than

Based on actual working conditions and parameters of the hydraulic steering gear, the purpose is optimizing the rubber seal of steering gear by different rubbers mixing technology. Compare the five kinds of rubber with metal of the friction characteristics in dynamic fit, it can obtain a performance excellent rubber real in the specific operation conditions. And then improve the overall service life of the steering gear. It is first prepared the same hardness TPU and PVC and blends that the ratio is 3:7, 5:5and7:3 in this article. The pros and cons of the five rubbers are analyzed in friction and wear properties of the above experimental. The test curve of coefficient friction and wear with time has been done under different load at constant low speed. It determines TPU/PVC = 3:7 blends through friction and wear and wear mechanism of five rubbers with steel comparatively analyses, and the heat resistance and wear resistance of them are better than the other TPU/PVC blends and PVC under oil lubrication conditions.

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