High transmission accuracy is crucial. As previously mentioned, belt transmission cannot guarantee an accurate transmission ratio, and chain transmission cannot achieve a constant instantaneous transmission ratio. However, the transmission ratio of the commonly used involute gears in modern times is theoretically accurate and constant. This is not only a key requirement for precision machinery and instruments but also an essential condition for reducing dynamic load and achieving smooth transmission under high-speed and heavy-load conditions.

2) Wide Application Range. Gear transmission offers an extremely broad power range, spanning from 0.001W to 60,000kW; circumferential speeds can be as low as desired, or as high as 150m/s, which is difficult to match by belt or chain drives.

3) It can achieve transmission between any two axes in space, such as parallel axes, intersecting axes, and meshed axes, which is something that belt and chain drives cannot accomplish.

4) Reliable performance, long service life.

The transmission efficiency is relatively high, generally ranging from 0.94 to 0.99.

6) High manufacturing and installation requirements result in higher costs.

7) Stringent environmental requirements generally necessitate installation in a dustproof and grease-proof housing, except for a few low-speed, low-precision cases. Proper lubrication should also be given attention.

8) Not applicable for transmission between two shafts that are far apart.

9) The vibration and shock resistance are not as good as those with belt drives and other flexible transmissions.