Stationary blade and steam turbine

摘要

A stationary blade and a steam turbine capable of reducing self-excited vibrations with a simple configuration are provided. A stationary blade has a cavity, extending in a blade-width direction, formed therein and slits communicating between the cavity and the outside. A wave-shaped plate spring that is in sliding contact with at least one of a pressure-side member and a suction-side member is provided between the pressure-side member, which is a portion on the pressure side of the cavity, and the suction-side member, which is a portion on the suction side of the cavity. When the stationary blade is elastically deformed, the wave-shaped plate spring causes friction between itself and at least one of the pressure-side member and the suction-side member. This friction attenuates relative positional displacement between the pressure-side member and the suction-side member. Thus, self-excited vibrations occurring at the stationary blade can be reduced.

主权项

1. A stationary blade for use in a steam turbine, having a cavity formed therein and having a slit formed for communicating between the cavity and the outside, the stationary blade comprising:
a sliding-contact member capable of contacting a blade inner face from the cavity in a slidable manner; a pressure-side portion, which is a portion on the pressure side of the cavity; and a suction-side portion, which is a portion on the suction side of the cavity, wherein the sliding-contact member is provided between the pressure-side portion and the suction-side portion and is in contact with at least one of the pressure-side portion and the suction-side portion, wherein the sliding-contact member is an urging member that urges the pressure-side portion and the suction-side portion outward in a blade-thickness direction, wherein the urging member is a plate-like spring member that has a plate shape extending in a blade-width direction and presses the pressure-side portion and the suction-side portion with an elasticity caused by distortion, wherein the plate-like spring member has a bow-shaped cross section and is in contact with one of the pressure-side portion and the suction-side portion at end portions of the bow shape and is in contact with the other at a base portion of the bow shape, and wherein an end portion of the plate-like spring member has a divided structure or a slit structure in which the end portion is divided into a plurality of plates in a plate thickness direction.