Four-gear linkage type brake clearance adjustment device

The invention discloses a four-gear linkage type brake clearance adjustment device. According to the four-gear linkage type brake clearance adjustment device, the functions of a manual adjustment mechanism and the functions of a driving adjustment mechanism are combined, the driving adjustment mechanism has a manual clearance adjustment function and an active clearance adjustment function but is not combined with an adjustment screw, only the adjustment functions and an anti-overload function are brought into play, the number of driven adjustment mechanisms is increased to two, two push rods are combined with the driven adjustment mechanisms, and the driven adjustment mechanisms are driven by the driving adjustment mechanism to achieve the movement of the two push rods. According to the structure, the driving adjustment mechanism is combined with a pressure arm, only the adjustment functions and the anti-overload function are achieved, and the driving adjustment mechanism is not associated with the screw; the driven adjustment mechanisms are combined with two adjustment screws, so that the phenomenon that the portions, connected with the adjustment screws, of the driven adjustment mechanisms are locked or get stuck due to the functions of the driven adjustment mechanisms do not work is avoided, in this way, normal work of a whole braking mechanism is not affected no matter whether the driving adjustment mechanism or the driven adjustment mechanism break down, and it can be guaranteed that braking is normal and effective under any conditions; in addition, the structures of the driven adjustment mechanisms are simplified, and thus both the braking parallelism and the braking stability are greatly improved.