Search results
Results from the WOW.Com Content Network
Both gas and liquid lubricants can transfer heat. However, liquid lubricants are much more effective on account of their high specific heat capacity. Typically the liquid lubricant is constantly circulated to and from a cooler part of the system, although lubricants may be used to warm as well as to cool when a regulated temperature is required.
A true grease consists of an oil or other fluid lubricant that is mixed with a thickener, typically a soap, to form a solid or semisolid. [1] Greases are usually shear-thinning or pseudo-plastic fluids, which means that the viscosity of the fluid is reduced under shear stress.
The most common one is a type of paraffinic crude oil, although there are also naphthenic crude oils that create products with better solubility and very good properties at low temperatures. By using hydrogenation technology, in which sulfur and aromatics are removed using hydrogen under high pressure, extremely pure base oils can be obtained ...
Due to the strong coupling between lubricant hydrodynamic action and the elastic deformation in contacting solids, this regime of lubrication is an example of Fluid-structure interaction. [4] The classical elastohydrodynamic theory considers Reynolds equation and the elastic deflection equation to solve for the pressure and deformation in this ...
A common type of degradation is the formation of tramp oil, also known as sump oil, which is unwanted oil that has mixed with cutting fluid. [17] It originates as lubrication oil that seeps out from the slideways and washes into the coolant mixture, as the protective film with which a steel supplier coats bar stock to prevent rusting, or as ...
Naphthenic oils have extraordinary low-temperature properties, high compatibility with many polymers and good solvent power. These are properties that make naphthenic oils particularly useful for the speciality oil market: 1. Transformer oils. Naphthenic oils have excellent cooling and insulating properties because of a low viscosity index.
The lubricity of a substance is not a material property, and cannot be measured directly. Tests are performed to quantify a lubricant's performance for a specific system. This is often done by determining how much wear is caused to a surface by a given wear-inducing object in a given amount of time. Other factors such as surface size ...
Some types are synthetic liquid lubricants that have been used in the aerospace industry for over 30 years. [1] The main properties of PFPE are being temperature resistant between −58 °C (215 K) and 257 °C (530 K) (depending on specific composites), having very low outgassing compared to other fluids ( vapour pressure of 6 × 10 −8 Torr ...