The main characteristics of gear transmission are:
1) High efficiency is the highest among commonly used mechanical transmissions, with gear transmission being the most efficient. The efficiency of a first level cylindrical gear transmission can reach 99%. This is very important for high-power transmission because even if the efficiency is only increased by 1%, it still has great economic significance.
2) Under the same usage conditions, the space required for gear transmission is generally smaller due to its compact structure.
3) A gear transmission with reliable operation, long service life, correct and reasonable design and manufacturing, and good use and maintenance can work very reliably, with a lifespan of up to one to twenty years, which is incomparable to other mechanical transmissions. This is particularly important for vehicles and machines working in mines.
4) Stable transmission ratio is often a basic requirement for transmission performance. Gear transmission has been widely used, which is due to its characteristic.
However, the manufacturing and installation accuracy requirements of gear transmission are high, the price is expensive, and it is not suitable for occasions with large transmission distances. Gear transmission can be made into open, semi open, and closed types. In agricultural machinery, construction machinery, and simple mechanical equipment, some gear transmissions do not have dust covers or casings, and the gears are completely exposed to the outside, which is called open gear transmission. This type of transmission is not only easily invaded by external debris, but also has poor lubrication, resulting in poor working conditions and easy wear of the teeth. Therefore, it is only suitable for low-speed transmission. When a gear transmission is equipped with a simple protective cover and sometimes partially immerses the large gear into the oil pool, it is called a semi open gear transmission. Although its working conditions have improved, it still cannot tightly prevent external debris from entering, and the lubrication conditions are not considered the best. The gear transmission used in automobiles, machine tools, aviation engines, etc. is installed in a precisely machined and tightly enclosed box (gearbox), which is called a closed gear transmission (gearbox). Compared with open or semi open, it has the best lubrication and protection conditions and is mostly used in important occasions.
