SPEED CHANGE CONTROL DEVICE FOR TROIDAL TYPE STEPLESS TRANSMISSION GEAR

摘要

PROBLEM TO BE SOLVED: To appropriately perform compensation of torque shift while steep surface of a cam set up to a precession cam for preventing from hitting a slant rolled stopper of a trunnion is feedbacked. SOLUTION: Transmission ratio TSrto for the compensation of the torque shift as shown in Fig.a is relatively largely set up associated with an angle slanted to small face of the cam for the precession cam which corresponds to the region of a practical transmission ratio relative to its region of the desired transmission ratio DRatio but in the region out of the practical transmission ratio on lower speed side than the lowest portion, the transmission ratio TSrto for the compensation of the torque shift is set up in a small way associated with the inclined angle because the face of the cam for the precession cam which corresponds to its region becomes to have a greater inclined angle for preventing from hitting the slant rolled stopper of the trunnion and consequently the transmission ratio prevents from suddenly changing when shifted from the region of the practical transmission ratio to the region out of the practical transmission ratio. Fig.b shows to make the transmission ratio TSrto for the compensation of the torque shift greater value than amount of practical torque shift even within the region of the practical transmission ratio in the transmission ratio (1.9) on somewhat higher side than the lowest portion, in this case, overshooting against input rotation of the transmission gear can be prevented when shift is stepped down in the case where the steep surface of the cam is biased to its lower side.