As is known to all, is indispensable to the successful landing of the AT the transmission planetary gear, in the absence of electronic control system power s, that the structure of the mechanical parts with its own unique advantages, make automatic shift, also makes its all-wheel-drive systems, won a place in the hybrid system, today still play an indispensable role in auto transmission system.
From the point of view of structure, planetary gear is not complicated, it is composed of three components, including the sun wheel, gear ring and planet frame. The rotation center of the three components coincides, the central position is the sun wheel, the outermost ring is the gear ring, and the pinion between the two is the planet wheel. The planet frame connects all the planet wheels together and combines them into a component.
In this structure, the planet carrier is transfer gear, gear ratio size it's not up to the actual number of teeth, we can regard it as a virtual spur gear, the teeth of the sun wheel and gear ring gear, the sum of planet carrier for maximum gear, and the center position of the smallest, the sun wheel teeth at least, therefore, is located in the outer ring gear ring is greater than the sun wheel, gear ratio between the above two.
During power transmission, if a single component in the structure is limited, the other two components will play a driving role. At the same time, because the number of teeth of each component is different, the restriction of different components can play a role of variable speed and torsion when the power is output.
Take one gear as an example, the power is input by the smallest gear sun wheel, the largest gear planetary frame output, so the gear ring is fixed. At this point, the sun wheel will push the planetary gear rotation, planetary gear rotation, because the gear ring fixed, so the rotation of the planetary gear ring will provide a counter force, around the sun wheel for revolution, drive its connected planetary frame rotation, power output.
Due to the same center of rotation of the active and passive parts of the planetary gear mechanism, the higher volume utilization of the planetary gear mechanism frees up more space for the shift actuator of the automatic transmission, allowing it to shift automatically without changing the volume. In addition, more planetary bars can be added to extend the speed range of the car.
In addition to speed regulation, planetary gears have other functions in the transmission system. Because its three components can rotate, the transmission of power can be "two in and one out", or "one in and two out", in the hybrid system can achieve flexible transmission of power, in the four-wheel drive system can also make the power distribution more reasonable, and play a differential effect.
Write at the end:
Planetary gear, with its simple and compact structure, makes AT a "hexagonal warrior" among automatic transmissions, and its reliability and power transmission limit, which is now widely used in dual clutch transmission, cannot be compared with CVT, which also contributes to its dominant position in the automotive development history. At the same time, in the all-wheel-drive system with hybrid cars also can see it, or even part of the new energy vehicle drive system needs to be a planet gear to achieve higher performance, which fully demonstrated the high quality mechanical structure of the mature not only out of date, will with the passage of time to continue in the mighty technology development, play is even stronger than before.