Push-and-pull structure of bearing box of steam turbine

The invention relates to a push-and-pull structure, in particular to a push-and-pull structure of a bearing box of a steam turbine, and aims to solve the problem of unsmooth expansion of a unit of anexisting steam turbine applying a cat claw push-and-pull sliding pin system. The structure comprises a steam turbine cylinder and the bearing box; a key groove is formed in a guide device of the cylinder; a guide key is arranged on the bearing box and is inserted in the key groove; the push-and-pull structure of the bearing box of the steam turbine further comprises a long tension key, a short tension key and a first gasket; the long tension key and the short tension key are arranged at the upper part of the guide key from left to right; the lower surface of the short tension key is fixedly connected with the upper surface of the guide key; the lower surfaces of the two ends of the long tension key are fixedly connected with a rotating shaft; and the first gasket is located between the long tension key and the sho