Patent ID: 9076560
Filing Date: 2015-07-07
Classification: F16B,G21C,Y02E

Abstract:
1. A bolt fixing device for a jet pump of a boiling water reactor, comprising: a jet pump beam formed with a screw hole penetrating the jet pump beam at a central position thereof; a rotatable head bolt having a polygonal head portion, the head bolt being screwed into the screw hole of the jet pump beam; a lock cap provided on the polygonal head portion of the head bolt, the lock cap being rotatable together with the head bolt and slidable in an axial direction of the polygonal head portion; a body housing disposed on an upper surface of the jet pump beam accommodating the lock cap; a plurality of external teeth which are formed to expand downwardly on an outer peripheral side surface of the lock cap; a plurality of internal tooth-shaped grooves which are formed to the body housing and selectively engaged with the external teeth of the lock cap to thereby fix the head bolt of the jet pump beam; and an elastic member, interposed between the upper surface of the jet pump beam and the lower surface of the lock cap, that urges the lock cap and the external teeth thereof upward so as to be engaged with the internal tooth-shaped grooves of the body housing, thereby preventing rotation of the head bolt, the lock cap and external teeth being disengaged from the internal tooth-shaped grooves when the lock cap is compressed against an urging force of the elastic member.