State the necessity of Balancing. List different types of Balancing methods.

Necessity of Balancing:
[1] The high speed of engines and other machines is a common phenomenon now-a-
days. It is, therefore, very essential that all the rotating and reciprocating parts should
be completely balanced as far as possible.
[2] If these parts are not properly balanced, the dynamic forces are set up. These
forces not only increase the loads on bearings and stresses in the various members,
but also produce unpleasant and even dangerous vibrations.
[3] The balancing of unbalanced forces is caused by rotating masses, in order to
minimize pressure on the main bearings when an engine is running.

Types of Balancing Methods:
[1] Balancing of rotating masses:
(a) Balancing of a single rotating mass by a single rotating mass in the same plane
(b) Balancing of a single rotating mass by two masses rotating in the different planes
(c) Balancing of different masses rotating in the same plane
(d) Balancing of different masses rotating in the different planes
[2] Balancing of Several masses revolving in same plane: