Question

The function of lubrication in engines are
1. lubrication and cooling
2. cleaning, sealing and noise reduction
3. efficiency enhancement
4. both 1 and 2

Answer 1

Correct Answer - Option 4 : both 1 and 2

Explanation:

The functions of a lubricant in an engine are many and varying, the common functions are:

• To reduce the friction between the components and metal to metal contact
• To reduce the overheating of the components i.e. to keep the parts cool.
• To prevent wear and corrosion of the components due to rubbing.
• The dirt particle present if any deteriorates the life of the engine. The lubricant also helps in removing it.

To accomplish these functions a lubricant should have:

• Suitable viscosity according to the load, a good lubricant should have a high viscosity index so that viscosity does not change much with temperature and pressure.
• Oiliness to ensure adherence to the bearings, and for less friction and wear when the lubrication is in the boundary region to protect against corrosion.
• A lubricant should have a high strength to prevent metal-to-metal contact under high load.
• Lubricant should be non-reactive with engine surfaces
• A low pour point.
• Non-reactive with air, water, fuel, or any other product of combustion
• Cleaning ability, non-toxic, non-flammable, non-foaming.