JET PUMP, AND BOLT AFFIXING DEVICE FOR JET PUMP BEAM

摘要

A bolt fixing device (35) for a jet pump beam comprises: a lock cap (36) which is fitted to the polygonal head portion (32) of a head bolt (30), can move in the vertical axis direction, and can rotate together with the head bolt (30); a body housing (37) which houses the lock cap (36) and which is installed on the upper surface of a jet pump beam (27); and an elastic member (40) which is provided within the body housing (37) at a position below the lock cap (36) and which applies an elastic force to the lock cap (36) in the vertically upward direction. The bolt fixing device (35) is configured so that the lock cap (36) is pushed up by the elastic force of the elastic member (40) and engages upper surface teeth with lower surface teeth, the upper surface teeth being formed on the upper surface of the flange of the lock cap (36), the lower surface teeth being formed on the lower surface of the engagement flange of the body housing (37). Thus, the head bolt (30) of the jet pump beam (27) is fixed. As a result of this configuration, when installing an inlet mixer, the head bolt of the jet pump beam is simply and reliably locked against rotation.