A pneumatic shifting force assistance device for a manual transmission is provided, comprising a housing structure having a compressed air inlet, ventilation, control rod, and an output unit comprising a working piston defining two pneumatic working chambers. A valve arrangement is provided between the control rod and output unit, bringing about a pneumatic sequential control from the outlet unit to the control rod by acting on the working chambers. The valve arrangement comprises two piston structures, two annular sealing edges, two valve slides which interact with the sealing edges, and two valve seats. At least one piston structure/valve slide pair is paired with a throttle device such that a throttle seal arranged on the output unit interacts with a throttle passage arranged on the corresponding valve slide or piston structure, where the effective cross-sectional area of the throttle passage depends on the position of the component within the throttle passage.

A universal operating device for an overdrive gearbox and a use method thereof, including a gearbox gear selecting and shifting shaft, and a gear selecting and shifting rocker arm and a gear selecting and shifting block which are arranged on the gearbox gear selecting and shifting shaft, where one end of the gearbox gear selecting and shifting shaft is separately in transmission fit with a gear selecting flexible shaft and a gear shifting flexible shaft through the gear selecting and shifting rocker arm, and the other end of the gearbox gear selecting and shifting shaft is in transmission fit with a gear shifting guide block through the gear selecting and shifting block; the gear selecting flexible shaft is in transmission fit with the gear selecting and shifting rocker arm through an overdrive gear switching device; and the overdrive gear switching device includes a gear shifting fork, the upper end of the gear shifting fork is in transmission fit with the upper end of the gear selecting and shifting rocker arm, and the lower end of the gear shifting fork is in transmission fit with the lower end of the gear selecting and shifting rocker arm. In use, the transmission direction of the gear selecting and shifting shaft is changed by utilizing the translation of the rocker arm without changing an inner structure of the gearbox. Therefore, the design is simple in structure and low in manufacture cost, and can realize gear order reverse shifting of the gearbox without changing the inner structure of the gearbox.