Enhanced shift couplers for shift-on-the-go transmission

A method for adding speed ratios to a power transmitter having a first transmission in series with an auxiliary transmission with a gear shift assembly having at least two speeds, the method comprising:

• providing the first transmission and the auxiliary transmission;
• providing at least two splines or gears within the auxiliary transmission having a chamfer from about 10° to about 45° on a leading or trailing rotational edge;
• mounting the gearshift assembly externally to the auxiliary transmission;
• controlling shifting of the auxiliary transmission from a first speed to a second speed, wherein speed ratios are added by shifting from a first speed to a second speed of the auxiliary transmission to raise or lower the output speed of the series;
• and
• aiding shifting of the transmission by meshing the at least two gears when the auxiliary transmission shifts from the first speed to the second speed of the transmission.

A two-speed auxiliary transmission, comprising:

• a two-speed gearbox having an input shaft, an output shaft, and a planetary transmission coupling the input shaft with the output shaft, the planetary transmission having at least one planet gear and a sleeve movable between two positions, a speed of the output shaft related to a speed of the input shaft by a first ratio in a first position and by a second ratio in a second position;
• a gear shift assembly mounted externally to the gearbox, said gear shift assembly having a motor and a gear reduction train for the motor driving a shifter, the assembly operably connected to the two-speed gearbox;
• and
• a control system acting upon the gear shift assembly and responsive to shift the sleeve between the two positions, wherein the sleeve has at least one spline for meshing with a first gear in the first position and with a second gear in the second position, and wherein at least one of the at least one spline, the first gear and the second gear is chamfered on a rotational trailing edge from about 10° to about 45°.