Pneumatic servomotor for braking assistance including a force sensor

摘要

The servomotor (1) has a sealed structure (3) including a rigid envelope (11) forming a vent (19). A mobile wall (13) divides the structure into a low pressure chamber (25) and a working chamber (27). A pneumatic piston (5) has a hub (31) integrated to the wall. Input and output rods (7, 9) are coupled on both sides of the piston. A return spring (37) returns the piston to a rest position and is arranged in the chamber (25) between an inner surface (45) of the envelope and piston. A force sensor (39) e.g. strain gauge, arranged in the chamber (25) is subjected to load variations of spring.