Search results for "Lubrication"
showing 10 items of 24 documents
Influence of residual stress, surface roughness and crystallographic texture induced by machining on the corrosion behaviour of copper in salt-fog at…
2012
International audience; The influence of quadratic stress, crystallographic texture, lubrication and surface roughness generated by superfinish turning on the corrosion behaviour of pure copper was quantified in salt-fog atmosphere. This was done using statistical analysis (Pearson's correlation matrix). Three compounds were found after corrosion tests: atacamite/paratacamite and a black layer (mixture of the lubricant and the salt atmosphere). Surface characteristics were classified according to their decreasing influence on the formation of atacamite/paratacamite as follows: surface roughness and quadratic stress. Lubrication and the crystallographic texture have the lowest influence on c…
Cutting Fluids
2008
This chapter provides comprehensive knowledge regarding cutting fluids (CFs), their classifications and basic categories, including non-water-miscible, water-miscible and water-based CFs. Main properties and application areas of these three CFs are characterized and specified. Such effects as cooling, lubricating and processing (i.e., the influence on the behaviour of the cutting process) resulting from supplying CFs are outlined. The strategies of delivering CFs to the cutting zone, including flooding, external and internal supply of pressured CFs, along with minimum-quantity lubrication techniques as well as cryogenically cooled gases (CO2 snow and liquid nitrogen (LN2)) are described. So…
Elastohydrodynamic Collision of Two Spheres Allowing Slip on Their Surfaces.
2000
Our goal is to study theoretically the effect of deformation on the collision of two solid spheres allowing slip on their surfaces. The deformed shape of the solid surface is determined via an asymptotic technique assuming that deformation is small compared with the separation between the surfaces. It has previously been shown that the slippage makes collision possible even without any surface attractive force. Here we demonstrate that even a small amount of deformation can preclude spheres from coagulation. Copyright 2000 Academic Press.
Thermo-Elasto-Hydrodynamic Analysis of a Crankshaft Journal Bearing
2006
This paper summarizes the essential parts of a numerical analysis activity in which the application of the Thermo-Elasto-Hydro-Dynamic (TEHD) lubrication theory to a crankshaft journal bearing is examined. The study is carried out through numerical computations performed by a commercial flexible-multibody code which simulates the lubricated contact between elastic bodies in large displacement motion. A multibody model has been created and its thermal behaviour has been validated by comparison with experimental temperatures. The validated model is used to perform two comparative analyses between the TEHD modelling and the Elasto-Hydro-Dynamic (EHD) modelling for max torque and max power cond…
Thermo-optical mirror on a free ferrofluid surface
1997
Here we report on the first, to our knowledge, direct experimental observation of giant thermo-optical mirror effect on the free surface of ferrofluid under He-Ne laser excitation. In our experiment a slightly focused laser beam of power in mW range is incident nearly normally to the surface, and a characteristic diffraction ring pattern has been observed in reflection mode. Concave surface deformation has been clearly observed at laser irradiated spot and has been explained in terms of lubrication theory approach for laser driven thermocapillary motion in thin layer of light absorbing fluid.
Industry 4.0: Advanced digital solutions implemented on a close power loop test bench
2021
Abstract The paradigm of Industry 4.0 allows to increase the efficiency and effectiveness of the production. Companies that will implement advanced solutions in production systems will increase their level of competitiveness and will be able reach high market shares. The present paper is focused on the development of advanced digital solutions to be implemented on a close power loop test bench designed to test high power transmissions for naval unit. In particular, the test configuration consists of a back-to-back connection between two identical mechanical reducers. Since the efficiency of these systems are very high, it is not necessary to use large electric motors, thus managing to conta…
Comparative study of the lubricant performance of Compritol® HD5 ATO and Compritol® 888 ATO: effect of polyethylene glycol behenate on lubricant capa…
2003
The aim of this paper is to study the lubricant capacity of Compritol HD5 ATO, a glyceryl and polyethylene glycol dibehenate, obtained by atomization. This material is compared to Compritol 888 ATO, constituted only by glyceryl dibehenate. First, this study verifies that Compritol HD5 ATO and Compritol 888 ATO present the same granular characteristics and that their mixes with Lactopress present no structural differences. Secondly, in term of compressibility and cohesiveness, the use of Compritol 888 ATO or Compritol HD5 ATO with Lactopress does not involve any significant modification. Finally, the minor difference of lubricant capacity between Compritol HD5 ATO and Compritol 888 ATO has n…
A Numerical Approach to Finite Journal Bearings Lubricated With Ferrofluid
1987
Several cases of cylindrical bearings lubricated with ferrofluid are examined by means of a finite-difference numerical procedure. The subregion of cavitation is determined by imposing mass conservation across the “rupture” and “reformation” boundaries of the complete film. The examined cases refer to bearings confined by sealing rings formed by the lubricant itself, for which there is no need of external supply. In each case the most significant parameters are calculated and it is possible to see that the use of these bearings is favorable when speeds are low, clearances large, and loads light, because in such conditions the magnetic effects are comparable with the pure hydrodynamic ones a…
The Surface of Ice under Equilibrium and Nonequilibrium Conditions
2019
ConspectusThe ice premelt, often called the quasi-liquid layer (QLL), is key for the lubrication of ice, gas uptake by ice, and growth of aerosols. Despite its apparent importance, in-depth understanding of the ice premelt from the microscopic to the macroscopic scale has not been gained. By reviewing data obtained using molecular dynamics (MD) simulations, sum-frequency generation (SFG) spectroscopy, and laser confocal differential interference contrast microscopy (LCM-DIM), we provide a unified view of the experimentally observed variation in quasi-liquid (QL) states. In particular, we disentangle three distinct types of QL states of disordered layers, QL-droplet, and QL-film and discuss…
Comparative study of the lubricant performance of Compritol 888 ATO either used by blending or by hot melt coating.
2003
Compritol 888 ATO is used as a lubricant in oral solid dosage formulations. It can also be used as a hot melt coating agent sprayed onto a powder. In this study, we compare the lubricant performance of Compritol 888 ATO either used by classical blending or by hot melt coating onto Lactopress by compression tests. In physical mix, the Compritol concentration does not affect the compressibility. The same compressibility is obtained with lactose coated by 0.5 or 1% of Compritol, but a higher compressibility can be observed with 2 and 3%. Cohesiveness of lactose depends on the process: hot melt coating induces a decrease of tablet tensile strength. In terms of forces transmission during compres…