Influence of Contamination of Gear Oils in Relation to Time of Operation on Their Lubricity (original) (raw)
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New Trends and Developments in Automotive Industry, 2011
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Axle gear oils: Tribological characterization under full film lubrication
Tribology International, 2017
The tribological properties of five axle gear oils are characterized. Three oils (75W90-A, 80W90-A and 75W140-A), available on the market and labelled as "Fuel Efficient", were selected together with two candidate products (75W85-B and 75W90-B). Their viscosity, film generation and traction properties were measured for three different temperatures under full film lubrication regime. The product formulation and the measured properties promote significant differences under full film lubrication. The film thickness is directly related with the Lubricant Parameter while the traction coefficient depends on the base oil and it decreases with the increase of Viscosity Index and the decrease of Piezoviscosity. So, new lubricants with lower viscosity but holding high VI and low Piezoviscosity are promising for this application.
Wear, 2005
Vibration and wear debris analyses are the two main conditions monitoring techniques for machinery maintenance and fault diagnosis. These two techniques have their unique advantages and disadvantages associated with the monitoring and fault diagnosis of machinery. When these techniques are conducted independently, only a portion of machine faults are typically diagnosed. However, practical experience has shown that integrating these two techniques in a machine condition monitoring program provides greater and more reliable information, bringing significant cost benefits to industry.
Axle gear oils: Friction behaviour under mixed and boundary lubrication regimes
Tribology International, 2017
The chemical composition of the axle lubricants and the tribological characteristics of the tribofilms are probed using measurement of friction, wear and film characteristics. Additives blended in the lubricants justified the frictional behaviour under mixed lubrication regime while surface texture and the tribofilm properties have substantiated the friction behaviour of the lubricant under boundary lubrication condition for high-lubricant temperature. This work will provide a comprehensive overview of two lubrication aspects and their effects on the lubricants friction behaviour through experimental tests using an EHD2 ball-on-disc apparatus. The effectiveness in friction reduction is shown depend on the ratio between what are defined as highand low-friction species in the tribofilm.
Power Loss in FZG gears lubricated with industrial gear oils: Biodegradable Ester vs. Mineral oil
Tribology and Interface Engineering Series, 2005
Two industrial gear oils, a reference paraffinic mineral oil with a special additive package for extra protection against micropitting and a biodegradable non-toxic ester, are compared in terms of their power dissipation in gear applications [1,2]. The physical properties, wear properties and chemical contents of the two lubricants are characterized. The viscosity-temperature behaviors are compared to describe the feasible operation temperature range. Standard tests with the Four-Ball machine and the FZG test rig characterize the wear protection properties. Biodegradability and toxicity tests are performed in order to assess the biodegradability and toxicity of the two lubricants. Friction and wear tests have been performed with a configuration that combines rolling/sliding in a line contact simulating the working conditions on gears. The results for the ester oil presented a lower friction coefficient and operating temperature throughout tthe test in relation to mineral oil. Power loss gear tests are performed on the FZG machine using type C gears, for wide ranges of the applied torque and input speed, in order to compare the energetic performance of the two industrial gear oils [ 3 ]. The results of the power loss gear tests show that the operating temperature of the ester oil is always smaller than that of the mineral oil. Lubricant samples are collected during and at the end of the gear tests [ 4 ]. The lubricant samples are analyzed by Direct Reading Ferrography (DR3) in order to evaluate the wear particles concentration (CPUC) and the index of wear particles severity (ISUC). Both parameters indicate that the gear lubricated with the mineral oil suffered more flank tooth wear than the one lubricated with the biodegradable ester. The influence of each lubricant on the friction coefficient between the gear teeth is discussed taking into consideration the operating torque and speed and the stabilized temperature.
Axle gear oils: Friction, wear and tribofilm generation under boundary lubrication regime
Tribology International, 2017
The internal friction torque measurements in Cylindrical Roller Thrust Bearings (RTB) lubricated with axle gear oils under boundary film conditions were performed using an axial rolling bearing test rig generating tribofilms. The X-ray photoelectron spectroscopy (XPS) was used to characterize the tribofilms formed on the bearing rollers and raceways. After the tests, wear debris were found on the oil samples which lubricated the surface of the roller bearing raceways for that surface topography measurements and oil analysis (ferrography) were mandatory to measure and to visualize the occurring wear. The results obtained indicate that axle gear oil formulations and their additive packages have got a significant influence in controlling roller bearing friction and wear under boundary film lubrication.
Experimental investigation of natural oils with and without additives in gear box lubrication
INSTRUMENTATION ENGINEERING, ELECTRONICS AND TELECOMMUNICATIONS – 2021 (IEET-2021): Proceedings of the VII International Forum
There is a steady increment in the interest of eco-accommodating bio-ointments. The present research work analyses the tribological properties and behavior of natural oil blends under consideration when used as lubricating oil for worm gear box for evaluating possibility of these selected blends to be used as an effective lubricant in future. A worm gear box test rig is designed for this investigation. Coconut oil and castor oil are nominated as base oils whereas natural garlic oil and rapeseed are nominated as EP & friction modifier additives respectively. Total four oil blends are experimented. A test plan is followed for operating the worm gearbox test rig & samples are collected. The tribological properties of these four oil blends are equated with the tribological properties of EP90 gear oil. With the tribological properties assessment of the nominated natural oil blends, it has been observed that the selected natural oils have very decent latent to be used as lubricating oils.
Effect of ageing automotive gear oils on scuffing and pitting
Tribology International, 2008
The aim of this work is to compare automotive gear oils of different performance levels (API GL) from the point of view of their resistance to degradation due to ageing. The influence of the gear oil degradation on scuffing and rolling contact fatigue (pitting) has been assessed. Two automotive gear oils of API GL-3 and GL-5 performance levels were tested. They were contaminated with dust, water and oxidation residues. It has been concluded that from the point of view of the resistance to scuffing the most dangerous contaminant is water. For the resistance to rolling contact fatigue the most dangerous are dust and water. In general, GL-5 oils are less vulnerable to deterioration due to ageing than GL-3 oils.
ABM Proceedings, 2014
For lubrication of open gear drives applied in rotary furnaces, often gear greases are used as well as for lubrication of gear boxes in difficult sealing conditions. The selection of the gear grease influences strongly the wear behavior. Investigations with flow greases NLGI 00 were made in a back-to-back test rig determining the weight loss due to wear acc. to the standardised procedure ISO 14635 part 3. Different influences like base oil viscosity, thickener type and additional solid lubricant type were analysed. Only the type and amount of solid lubricant shows a significant influence on the weight loss due to wear. Finally, a linear wear coefficient clT according to the calculation method of the wear amount according to Plewe is derived and can be used to transfer the test results to any gears in practice.
Friction and wear characteristics of waste vegetable oil contaminated lubricants
International Journal of Mechanical and Materials Engineering, 2011
In this paper, a four-ball tribotester was used with standard test method IP-239 to evaluate friction and wear characteristics of normal lubricant, additive added lubricant and waste vegetable oil (WVO) contaminated lubricants. The balls used in four-ball tribotester were based on carbon-chromium steel ball bearings. The results obtained to present friction and wear characteristics are coefficient of friction (μ), wear scar diameter (WSD), flash temperature parameter (FTP), viscosity index (VI) and total acid number (TAN). Each test was conducted for five different loads from 50 kg to 90 kg with an interval of 10 kg. The lubricant was contaminated with WVO from 1% to 5%. The normal lubricant (as sample A) was used for comparison purposes. The test results showed that WVO contaminated lubricants with suitable anti-wear additive can reduce wear and friction coefficient. The objective of this investigation is to develop a new lubricant based on waste palm oil (such as WVO).