Why does the planetary gear mechanism determine only one of the motions of the gear ring, the planet carrier, and the sun wheel?

Answer:

(2 clutches and 2 brakes and 1 one-way overdrive clutch), to be a planetary gearbox with 3 forward and 1 reverse, the 5 shift operation component layout as shown in Figure 7-5, C1 is used to connect the clutch input shaft and the clutch wheel assembly before and after the sun. C2 is used to connect the input shaft and the ring gear, brake for B1 solid was fixed after the planet carrier, B before and after the sun wheel brake assembly, brake B2 and one-way overdrive clutch F11 and B2 can be used with brake or disc brake

It is composed of two type internal meshing planetary gear mechanism combination, its structure is characterized by (1) before and after the two planetary sun gear is connected into a whole, called the sun before and after the wheel assembly (2) in front of a ring gear planetary frame of the planetary row and a planetary row connect to another one, called on star frame and a rear ring gear assembly (3) and the output shaft is usually the former planet carrier and the ring gear assembly (Figure 7-4). Thus, the mechanism becomes one of these 4 independent components, which are (1) front ring gears (2), front and rear sun wheel assemblies (3), rear star frames (4), front planetary frames and rear ring gear assemblies;

The planetary gear mechanism and the relative shift operation assembly are used by most automatic transmissions at present;