Oils are lubricants used primarily to reduce friction, notably in aeroplane & helicopter drivetrains.
However, oils can also prevent corrosion (by forming a waterproof barrier) and can carry away waste products for elimination by filtering.
There are two main families of oils:
- Mineral oils: these oils are obtained from base oils, derived directly from crude oil, which are then enriched with chemical additives to improve their performance, notably the lubricity of the base oil. The specific additives used are chosen based on the intended application.
- Synthetic oils: these oils may be semi-synthetic, i.e. a blend of mineral oil and synthetic oil or 100% synthetic.
To match the oil to the intended application, manufacturers may adjust its viscosity and improve its performance by including one or more additives: corrosion inhibitors, antiwear agents, oxidation inhibitors, etc.
There are many different fields of application for oils in aeronautics:
- Oils for drivetrains
- Oils for instruments
- Oils for transmissions
- Oils for fuel circuit components