Braking system and passenger boarding bridge

A braking system for a passenger boarding bridge that comprises a tunnel having a cabin, a cab and a rotationally driving device that comprises a driving motor mounted on the cab, a driving wheel mounted on an output shaft of the driving motor, and two driven wheels mounted on the tunnel and one drive belt being in cooperation with the driving wheels and the driven wheels, and having two ends fixed on the cabin respectively, wherein the braking system comprises:

• a locking member fixedly mounted on the cabin;
• at least one set of braking assemblies, each of which comprises an oscillating member rotatably mounted on the cab, an oscillating wheel mounted on the oscillating member and an elastic member, wherein the elastic member presents a pre-tightening force, the oscillating wheel cooperates with an outer side of the drive belt to form an abutting force so as to balance the pre-tightening force of the elastic member when the drive belt is in a normal working state, the pre-tightening force of the elastic member rotates the oscillating member to a direction of the locking member and cooperates with the locking member in a locking manner to realize braking when the length of the drive belt between the driven wheel and the driving wheel exceeds a preset value or is in a broken state.