POWER TRANSMISSION DEVICE

摘要

PURPOSE: To provide a power transmission device with high efficiency and excellent shift performance. CONSTITUTION: This transmission device has 16 forward speeds and 4 backward speeds. A gear ratio is selected so as to give a comparatively large gear ratio interval for a low speed PTO range and a high speed transportation range and a considerably high gear ratio interval for an intermediate tilling speed range. The gear ratio is selected so that the number of clutches when the gear is shifted from one speed to another is to be the minimum and the differences between speeds and momenta of the power transmission device between shifts is to be the minimum. Large gear variation is given to only two shifts and those two shifts are assigned to a range used extremely low times. Consequently the operator almost does not notice the large gear ratio interval. Extremely high transmission efficiency is obtained by reducing the meshing number of gears as far as possible.