Among various transmission forms, gear transmission is the most widely used in modern machinery. This is because gear transmission has the following characteristics:
1) High transmission accuracy. As mentioned earlier, belt transmission can not ensure accurate transmission ratio, and chain transmission can not achieve constant instantaneous transmission ratio, but the transmission ratio of involute gear commonly used in modern times is accurate and constant in theory. This is not only a key requirement for precision machinery and instruments, but also an important condition for reducing dynamic load and realizing smooth transmission under high speed and heavy load.
2) Wide application range. The power range transmitted by gear transmission is very wide, which can range from 0.001w to 60000kw; The circumferential speed can be very low or as high as 150m / s, which is difficult to compare with belt drive and chain drive.
3) It can realize the transmission between any two axes in space such as parallel axis, intersecting axis and staggered axis, which can not be achieved by belt transmission and chain transmission.
4) Reliable operation and long service life.
5) The transmission efficiency is high, generally 0.94 ~ 0.99.
6) Manufacturing and installation requirements are high, so the cost is also high.
7) The requirements for environmental conditions are strict. Except for a few cases of low speed and low precision, it generally needs to be placed in the box cover to prevent dust and scale, and attention should also be paid to lubrication.
8) It is not applicable to the transmission between two shafts far apart.
9) Vibration damping and impact resistance are not as good as flexible transmission such as belt transmission.