STEPLESS SPEED CHANGE GEAR

PURPOSE:To obtain high efficiency of transmission and wide range of speed change with simple construction in a stepless speed changer of planetary wheel friction method, by constituting a kind of bearing from a sun wheel, planetary wheels and ring. CONSTITUTION:A cam plate 6 consisting of a straight pipe part 4 and disc 5 is movably fitted to a sun wheel shaft 1 of input shaft, and a pin 2 on the sun shaft 1 is engaged to a cam groove 7 in the cam plate 6. Further a cylindrical sun wheel inner ring 9 is movably fitted to the sun sjaft 1, and a protruding part 8 integrally formed with the cam plate 6 is fitted to a straight moving groove 10 in one end of the inner ring 9. To the periphery of the inner ring 9, sun wheel outer rings 13a, 13b are movably fitted, then to their diagonal grooves 17a, 17b, pins 12a, 12b of the inner ring 9 are engaged. Disc parts 15a, 15b are contacted to the periphery of the outer rings 13a, 13b, for instance, four counter bead-shaped planetary wheels 20 are arranged. Speed changed rotation in accordance with a contact position of rings 24a, 24b contacted to said planetary wheel 20 is transmitted to an output shaft 39 through a ring case 32.