The substances which are used to decrease the force of friction between the moving parts of machine in contact are known as Lubricants and the process of decreasing the force of friction between the moving parts of machine in contact is known as Lubrication.
When on surface of machinery moves over the another surface, resistance to relative motion of the surfaces arises. When we look at the solid surface it appears smooth to naked eye , but this smooth surface shows irregularities of projections and cavities when viewed under high power microscope.
cavities in surfaces:
When one such surface is placed over another, its projections fall into the cavities of the other and get interlocked .Due to this interlocking , there is resistance to the relative motion of the surfaces. This is called the frictional forces or frictional resistance of friction. In due course of motion, the old projections get broken and deformities arise.
Friction:
Friction may be defined as the opposing force that is set up between the surface of contact, when one body moves over the surface of another body.
When on surface of machinery moves over the another surface, resistance to relative motion of the surfaces arises. When we look at the solid surface it appears smooth to naked eye , but this smooth surface shows irregularities of projections and cavities when viewed under high power microscope.
cavities in surfaces:
When one such surface is placed over another, its projections fall into the cavities of the other and get interlocked .Due to this interlocking , there is resistance to the relative motion of the surfaces. This is called the frictional forces or frictional resistance of friction. In due course of motion, the old projections get broken and deformities arise.
Friction:
Friction may be defined as the opposing force that is set up between the surface of contact, when one body moves over the surface of another body.
The frictional forces oppose the relative motion between the moving parts of a machine. Therefore extra energy has to be spent to overcome the friction , which increases expenses of energy .The friction between the moving parts of machines also produces heat which causes damage to the machinery. Thus friction causes wear and tear of the moving parts of machinery in contact and due to this the machines lose their efficiency and become useless.
Functions of Lubricants:
- Lubricants avoid the damage of the moving parts of machines by minimizing the production of heat.
- Lubricants reduce the wear and tear of machinery by keeping the moving parts of machines apart.
- Lubricants reduce the maintenance and running cost of machine.
- Lubricants act as the coolant because it reduces the production of heat between the moving parts of machine in contact.
- Lubricants increases the efficiency of machine by reducing the loss of energy.
- By using the lubricants, the relative motion of the moving parts of machine becomes smooth and noise level of running machine reduces.
- Lubricants also act as the corrosion preventers.
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