Planetary gear transmission for a light vehicle such as a motorcycle

摘要

A transmission used as part of a drive unit to transmit power is coupled to a V6 engine drive shaft by a torque converter and includes an axially extending ring gear assembly, a sun gear positioned coaxially within part of the ring gear assembly and two planetary gear assemblies each spaced axially from the other and meshing with the sun gear and the ring gear assembly. The ring gear assembly is driven in rotation about its axis and an output drive shaft by the rotational forces of the motor output shaft and includes two different diameter annular ring gears which are each centered on and extend radially about the transmission axis. The annular ring gears have different diameters and radially inwardly extending teeth. The sun gear includes a portion axially aligned within each of the two ring gears. A clutch plate or pack, gearing or other band or pressure brake is provided to selectively permit or prevent the rotation of the sun gear about the transmission axis and relative to the output drive shaft. A first planetary gear assembly includes one or more planetary gear pinions meshing with the teeth of the smaller diameter ring gear and its axially aligned portion of the sun gear. The planetary gear pinions are each rotatably mounted to a first planetary carriage which in turn is coupled to the output drive shaft. The second other planetary gear assembly includes at least one second planetary gear pinion meshing with the teeth of the larger diameter ring gear and the portion of the sun gear aligned therein. The second planetary gear pinions are rotatably mounted to pivots coupled to a second gear carriage which in turn is selectively rotatable about the axis. A brake is provided operable to permit or prevent the rotation of one or both of the first planetary gear carriage or the second planetary gear carriage relative to their respective pivots. A second brake provided to selectively lock or unlock the sun gear so as to permit or prevent its rotation relative to the transmission axis.