A gear transmission (20) includes a plurality of shift gears (36, 37), a plurality of shifters (55, 56) engaged, respectively, with the plurality of shift gears (36, 37), and a shift drum (58) rotatably operated by a stepped speed changing operational tool (66) to operate the plurality of shifters (55, 56), thus being speed-changed in forward three speed stages. The stepped speed changing operational tool (66) is switched to a neutral position, a forward third speed position, a forward second speed position and a forward first speed position in this cited order.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. A shift actuator selectively couples the input shaft to the main shaft by rotatably coupling gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A controller controls the shift actuator utilizing an actuating pulse and an opposing pulse.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A shift control circuit operates a shift actuator using a first opposing pulse command and a first actuating pulse command, and releases pressure with shift actuating and opposing volumes of the shift actuator upon determining a shift completion event.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. A shift actuator selectively couples the input shaft to the main shaft by rotatably coupling gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A controller controls the shift actuator utilizing an actuating pulse and an opposing pulse.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. A shift actuator selectively couples the input shaft to the main shaft by rotatably coupling gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A controller controls the shift actuator utilizing an actuating pulse and an opposing pulse.

A gear transmission (20) includes a plurality of shift gears (36, 37), a plurality of shifters (55, 56) engaged, respectively, with the plurality of shift gears (36, 37), and a shift drum (58) rotatably operated by a stepped speed changing operational tool (66) to operate the plurality of shifters (55, 56), thus being speed-changed in forward three speed stages. The stepped speed changing operational tool (66) is switched to a neutral position, a forward third speed position, a forward second speed position and a forward first speed position in this cited order.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A shift control circuit operates a shift actuator using a first opposing pulse command and a first actuating pulse command, and releases pressure with shift actuating and opposing volumes of the shift actuator upon determining a shift completion event.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A shift control circuit operates a shift actuator using a first opposing pulse command and a first actuating pulse command, and releases pressure with shift actuating and opposing volumes of the shift actuator upon determining a shift completion event.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A shift control circuit operates a shift actuator using a first opposing pulse command and a first actuating pulse command, and releases pressure with shift actuating and opposing volumes of the shift actuator upon determining a shift completion event.

A shift drum has a recess which controls a fork to move one of two cooperating coaxially arranged gears for transmitting torque in a power train of a vehicle. The recess includes a straight section, which upon rotation of the shift drum does not move the fork either to the left or the right, and at least one ramp which does move the fork in one direction (i.e., to the left or the right). The ramp is more complex than a single line, such as having a first portion at a first right-shift portion ramp angle β and a second portion at a second right-shift portion ramp angle γ, perhaps with the intersection between the first right-shift portion ramp angle β and the second right-shift portion ramp angle γ being at the mid-line defined by the straight section of the recess.