Water drainer of main circuit breaker for electric locomotive

The utility model relates to a water drainer of a main circuit breaker for an electric locomotive. The utility model is composed of a casing body which is provided with a water inlet and an inner and an external water outlets. The utility model is characterized in that the interior of a casing body which is radial to the water inlet an upper air chamber and a lower air chamber which are formed by that an inner cavity of the casing body is divided into the upper air chamber at the upper section and the lower air chamber at the lower section by a valve rod, a reset spring, a carrier frame, a spring seat and a film leather cup; the upper air chamber is communicated with the water inlet; the lower air chamber is communicated with the inner and the external water outlets; the film leather cup and a variable and lockable gap which is between inner cavity bodies of the upper air chamber are namely water accumulation passages; the lower part of the valve rod is provided with a valve cover, and passages under the valve cover are the inner and the external water outlets. The water drainer has the advantages that the water drainer which is combined with the main circuit breaker is enabled to realize automatic drain, to drain the accumulated water in time, and to provide reliable assurance for the safe operation of the main circuit breaker.