1. The use of bearing surfaces that are themselves sacrificial, such as low shear materials, of which lead/copper journal bearings are an example.
2. Replace sliding friction with rolling element friction, such as with the use of rolling element bearings.
What is work done against friction?
When you move something that has a resisting force, like friction, then not all the energy you put in (work done) goes to kinetic energy. Some of the energy is lost to friction and dissipated as heat. That is called work done against friction.
Friction always acts to oppose any relative motion between surfaces. For the simple example of a book resting on a flat table, the frictional force is zero. There is no force trying to move the book across the table, so there is no need for a frictional force because there is nothing for the frictional force to oppose.
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Answer:
There are several ways to reduce friction:
1. The use of bearing surfaces that are themselves sacrificial, such as low shear materials, of which lead/copper journal bearings are an example.
2. Replace sliding friction with rolling element friction, such as with the use of rolling element bearings.
What is work done against friction?
When you move something that has a resisting force, like friction, then not all the energy you put in (work done) goes to kinetic energy. Some of the energy is lost to friction and dissipated as heat. That is called work done against friction.
Friction always acts to oppose any relative motion between surfaces. For the simple example of a book resting on a flat table, the frictional force is zero. There is no force trying to move the book across the table, so there is no need for a frictional force because there is nothing for the frictional force to oppose.