There are several ways to reduce friction: The use of bearing surfaces that are themselves sacrificial, such as low shear materials, of which lead/copper journal bearings are an example. Replace sliding friction with rolling element friction, such as with the use of rolling element bearings.
Hereof, why do we reduce friction?
Objects moving through fluids such as air or water also encounter frictional forces which reduce their motion. This is known as drag. Friction prevents objects from moving or slows them down. It also causes wear on surfaces as they rub against each other and generates heat.
How does a lubricant help in reducing friction?
Lubricant. A lubricant is a substance, usually organic, introduced to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, transporting foreign particles, or heating or cooling the surfaces.
How is oil used to reduce friction?
If you put a liquid like oil between two solid gears, it will shift about and change its shape as much as it needs to, cushioning the microscopic bumps between the gears as they mesh together and reducing the friction between them. The layers will slide freely past one another, so helping to reduce friction (3).