Rail transit bridge expansion and contraction device

The utility model belongs to the technical field of expansion and contraction devices, and discloses a rail transit bridge expansion and contraction device which is mainly technically characterized in that the device comprises a waterproof rubber strip with flanges at two ends, the two ends of the waterproof rubber strip are connected with channel steel with a pressing plate, and a cam shaft is arranged between the channel steel and the pressing plate. A support made of the channel steel replaces profile steel of a traditional expansion and contraction device, and the rail transit bridge expansion and contraction device is simple in structure, easy to construct and low in manufacturing cost. The waterproof rubber strip penetrates through a gap between the channel steel and the pressing plate and is clamped by the flanges to achieve a fine waterproof effect. The rail transit bridge expansion and contraction device has the main advantages that lifting of the pressing plate is controlled by the cam shaft, the pr