Advantages and disadvantages of gears

1. By using gear trains, large velocity ratio can be obtained with minimum space.
2. Gears are mechanically strong, so higher loads can be lifted.
3. Gears are used for transmission of large H.F.
4. They are used for transmitting motion over small centre distance of shafts
5. They are used for large reduction in speed and for transmission of torque.
6. Gears require only lubrication, hence less maintenance is required.
7. Using gear systems, we can transmit motion between non-parallel intersecting shafts.
8. They are used for positive drive, so its velocity ratio remains constant.
9. They have long life, so the gear system is very compact.

Disadvantages of gears

1. They are not suitable for large velocities.
2. They are not suitable for transmitting motion over a large distance.
3. Due to the engagement of toothed wheel of gears, some part of machine may get permanently damaged in case of excessive loading.
4. They have no flexibility.
5. Gear operation is noisy.