The simple (single-row) planetary gear mechanism is the basis of the speed change mechanism. Generally, the speed change mechanism of an automatic transmission is composed of two or more than three lines of planetary gear mechanisms. The simple planetary gear mechanism includes a sun gear, several planetary gears, and a gear ring, wherein the planetary gear is supported by a fixed shaft of the planet carrier, allowing the planetary gear to rotate on the support shaft. Planetary gears and adjacent sun gears and ring gears are always in constant meshing state. Helical gears are usually used to improve the smoothness of work.
In a simple planetary gear mechanism, the sun gear is located at the center of the planetary gear mechanism. The sun gear and the planet gear often mesh, and the two external gears mesh in opposite directions of rotation. Just as the sun is at the center of the solar system, the sun wheel is named for its location. In addition to being able to rotate around the planet carrier support axis, the planet gear will also rotate around the central axis of the sun gear under the circumstances of the planet carrier. This is like the rotation of the earth and the revolution around the sun. When this happens, it is called a planetary gear mechanism. In the entire planetary gear mechanism, for example, the rotation of the planet gear exists, and the planet carrier is fixed. This method is similar to a parallel shaft transmission called a fixed shaft transmission. The ring gear is an internal gear. It often meshes with the planetary gear. The internal gear and external gear mesh. The rotation direction is the same between the two. The number of planetary gears depends on the design load of the transmission, and usually there are three or four. The more the number, the greater the load.
A simple planetary gear mechanism is usually called a three-member mechanism, and the three members are the sun gear, the planet carrier, and the ring gear. If these three components are to determine the relationship between each other, generally one of the components needs to be fixed first, then determine who is the active part, and determine the speed and rotation direction of the active part. Already.
