Pneumatic brake pedal module

A pneumatic brake pedal module for a brake-by wire brake system of a vehicle, comprising:

• a pivotably mounted brake pedal and a damping unit, which is mechanically coupled to the brake pedal in order to generate a resistance when the brake pedal is actuated,
• wherein the damping unit comprises a housing and a piston movably mounted in the housing and dividing an internal space of the housing into a pressure chamber and a vacuum chamber,
• wherein the pressure chamber and the vacuum chamber are connected to one another in terms of flow and the piston has a piston end that defines a running surface having an encircling annular space in which a ring seal is accommodated in an axially movable manner,
• wherein the annular space is defined by first and second axial boundary surfaces spaced apart from one another and a cross web radially connecting the first and second axial boundary surfaces,
• wherein the first axial boundary surface is formed from the piston end and the second axial boundary surface is disposed on a wall member extending from the cross web radially outwardly,
• wherein the ring seal is located at least in a flow path between the pressure chamber and the vacuum chamber and forms a restrictor in the at least one flow path,
• wherein the restrictor is configured to provide asymmetric damping by selectively freeing different flow cross sections depending on the axial direction of piston movement, and wherein the ring seal, rest selectively against the first axial boundary surface or the second axial boundary surface and thereby either (i) blocks substantially all flow along the running surface into one of the chambers or (ii) frees flow along the running surface into the other chambers, and
• wherein a plurality of first openings through the piston leading from the annular space into the pressure chamber has a larger total flow cross-section than a plurality of second openings through the piston leading from the annular space into the vacuum chamber.