An amazing invention: Planetary gear set
Planetary gear set are not only widely used in automatic transmissions, but also in other transmission institutions are widely used.What is the planetary gear set? In fact, we show the structure of the planetary gear set that we can understand, and its structure just like the solar system, the middle of the sun, next to the several planets, the planets themselves rotating around the sun at the same time, due to the number of teeth, will produce variable speed , To achieve the purpose of speed deceleration. In fact, for the astronomical calendar needs, planetary gears also first appeared in astronomical instruments and watches, so the history has been very long.
A typical single row of planetary gear sets can be fixed by a different clutch and brake to achieve a different ratio of power transmission. Planetary gear sets also have double-row form, for control and processing to put higher requirements, relatively uncommon in the car.Since there are multiple components in the planetary gear set, the transmission ratio will change as long as the rotation of one of them is changed and the input and output of the power are changed, and when two or more planetary gear sets are changed together, which is the basic principle of AT transmission. Such as the majority of 6-8 speed AT transmission, there are three planetary gears.
CVT and other automatic transmission which also often have planetary gears, but this time they are often not as the main transmission mechanism (chain or strip + cone wheel is the main force of the shift), but as a vice variable speed mechanism. Although this will increase the complexity and cost of the transmission, but also to further enhance the economy.