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A Review on Tribological Investigations for Automotive Applications
Published in Jitendra Kumar Katiyar, Alessandro Ruggiero, T.V.V.L.N. Rao, J. Paulo Davim, Industrial Tribology, 2023
Vipin Goyal, Pankaj Kumar, Pradyumn Kumar Arya, Dan Sathiaraj, Girish Verma
Lubrication is the process of minimizing wear and friction between movable contact areas by providing a friction-reducing layer between them. This friction-reducing layer, often referred to as a lubricant, might be a solid, liquid, or plastic substance, the most prominent of which are oil and grease. Lubricants perform several functions: minimizing wear and friction; reducing corrosion; maintaining temperature and heat; transmitting power; and establishing a liquid sealing. Lubrication regimes specify the nature of lubrication film and are classified into three categories, boundary, mixed, and full film, as shown in Figure 11.8. Boundary lubrication is related to metal-to-metal interaction and occurs when the equipment is started and stopped frequently, as well as under heavily loaded conditions. There are two types of full-film lubrication known as hydrodynamic and elastohydrodynamic lubrication. Several parameters, such as load, speed, motion, and temperature, affect the engine’s tribological performance, which must be analyzed before the lubricant selection. The first parameter of the tribological system is a type of motion such as sliding or rotary motion. When motion between two contact surfaces is sliding, hydrodynamic lubrication theory would be used for analysis, whereas elasto-hydrodynamic lubrication theory would give better results for rolling motion.
Drilling Speeds
Published in C.P. Chugh, Ken Steele, V.M. Sharma, Design Criteria for Drill Rigs: Equipment and Drilling Techniques, 2020
C.P. Chugh, Ken Steele, V.M. Sharma
Lubrication is of great importance, both because it reduces wear and hence minimises the above effects, and because it decreases friction. The loss of transmitted energy in an unlubricated machine is shown by overheating of the rock drill cylinder and front head.
Maintenance
Published in J. T. McGuire, Pumps for Chemical Processing, 2020
The procedures covered by this term are carried out periodically to keep the machine running at its optimum. In order of decreasing frequency, the usual procedures for pumps are: Seal adjustment: packed box and adjustable Chevron seals need adjustment to take up wear and minimize leakage. Not adjusting such seals results in high leakage and can lead to major damage to seals or bearings or both if allowed to persist.Lubrication: bearings and “mechanisms” require lubrication. In some arrangements the assembly has to be dismantled, cleaned, and relubri-cated, usually with grease. Other arrangements use oil, which has to be changed. The frequency of lubrication depends upon the machine, the service, and the environment in which it is operating.Wear: some pump types, centrifugal pumps with axial clearances at the impeller for example, can be adjusted to compensate for clearance wear. This procedure would be employed whenever the pump showed an obvious drop in performance, or perhaps periodically until a trend was determined.Drive: coupling alignment tends to change with time, so periodic checking and correction is warranted. V belt drives require retensioning to compensate for stretch. Failure to attend to the drive can result in serious damage to both the drive and the connected equipment.
Synergistic lubricating behaviors of Zn-MOF/[P88814]DEHP composite used as lubricating oil additive
Published in Petroleum Science and Technology, 2023
Jue Wang, Heng Zhang, Wei Wu, Zeyun Wang
According to statistics, nearly one-third of energy consumption is caused by friction and about 80% of mechanical component failures are caused by various forms of friction and wear (Wen, Huang, and Tian 2018). Lubrication plays an indispensable role in saving energy and prolonging the service life of mechanical equipment (Cai et al. 2013). The use of lubricating oil has proven to be an effective strategy to minimize interface friction and thus improve energy utilization efficiency in varied mechanical systems. The lubricating oil is generally composed of approximately 90% base oil and 10% additives. Investigations have shown that blending micro or nanoscale solid particles into the lubricating oil can lower its friction and wear (Mujtaba et al. 2021). Two-dimensional (2D) layered inorganic materials, such as graphene, molybdenum disulfide (MoS2), tungsten disulfide (WS2) and hexagonal boron nitride (h-BN) have attracted great attention as lubrication additives due to their excellent tribological performance originating from the weak interlayer interaction and easy sliding between surrounding atomic layers (Koren et al. 2015). Compared with the conventional organic lubricant additives, such as zinc dialkyl dithiophosphate (ZDDP) and molybdenum dithiocarbamate (MoDTC), 2D inorganic materials exhibit enhanced chemical stability which results in less harmful emissions and lower toxicity, making them candidates for environmentally friendly lubricant additives (Uzoma et al. 2020).
Optimization of the lubricating oil inventory policy applied in a mining company
Published in International Journal of Mining, Reclamation and Environment, 2021
Sena Senses, Onur Golbasi, Ismail S. Bakal
Lubrication is the process of control of friction, heat transfer caused by abrasion, wear and tear between moving surfaces in contact to ensure that the large machinery and heavy-duty equipment can perform adequately. The supporting substances that provide better performance with a longer life are the lubricants. They can address various industrial machinery issues, so they are critical for the machinery industry’s progression. There are four main types of industrial lubricants, which are fluid lubricants (oils), semi-solid lubricants (greases), solid lubricants (dry lubricants), and synthetic lubricants (pastes). The most common types of industrial lubricants are oils and greases. Oil lubricants are mostly used in moving parts such as hinges, bearings, tool maintenance, and sharpening blades, or hydraulic mechanisms such as brakes, excavators, and pumps. On the other hand, greases can be used when lubricants are required to stick to surfaces for a long time and stay put. They can also be used as barriers to protect the parts from extreme heat, rust, and corrosion by sealing out the containments such as water and dust. They are generally used in gears, bearings, chains, and linkages. An improper lubrication inventory policy and lubrication application schedule in a machine-intensive sector, such as mining, may cause catastrophic issues in working systems’ functionality, resulting in a massive production loss.
Tribological characteristic evaluation of coconut oil dispersed with surfactant modified ceria-zirconia hybrid nanoparticles
Published in Tribology - Materials, Surfaces & Interfaces, 2019
Jibin T. Philip, Chacko Preno Koshy, M. D. Mathew, Basil Kuriachen
Lubrication is the science of reducing friction between interacting surfaces. The uncontrolled exploitation of crude oil reserves by the man kind combined with its diverse grave environmental effects has enforced the retreat to other alternative solutions [1]. Promising amount of investigations has been performed on the mineral oils during the past decades to improve its properties as base-oil for the lubricants as well as to control the large amount of exhaust emissions produced by it. In addition, the effect of various factors which affect the lubrication regimes viz. addition of oil soluble friction modifier additives [2], presence of unsaturation [3], use of organo-amine and organophosphate molybdenum complexes [4], tribo-film formation [5], fuel efficiency [6] and viscosity index improvers [7] were studied in detail by many investigators. The researches on vegetable oil, viz. palm oil [8], rice bran oil [9], coconut oil [10], and rubber seed oil [11,12] as a potential substitute for petroleum-based oils have been an active area of investigations for many years. Currently, they find applications locally, but are not widely commercialized due to some critical drawbacks in its properties for being used a lubricant [13,14]. Nevertheless, the enhanced lubricating properties of vegetable oils such as high viscosity index, low volatility and good lubricity along with its eco-friendly features viz. biodegradability, renewability, non-toxicity etc. has increased their demand [15].