Hitachi, Ltd.

Tetsu Imai

Kazuo Ikeuchi

Michio Kuroda

Kiyoshi Namura

Fumio Kato

Yoshiaki Yamazaki

Akio Sohma

Akira Ishida

Tutomu Iwasaki

A plurality of turbine buckets annularly arranged around a rotor are each provided with a ledge disposed at right angles to the outer surface of each bucket. Each ledge includes a leading end portion and a trailing end portion each formed therein with a vertical hole, leading and trailing end portions of the ledge of each turbine bucket extending in opposite directions on both sides of the bucket. There are provided cover pieces each interposed between ends of the adjacent two turbine buckets and formed on the upper surface with a plurality or cylindrical projections adapted to be loosely received in the vertical holes formed in the ledges of the adjacent two turbine buckets. Contact surfaces adapted to be brought into contact with the undersides of the ledges are formed on the upper surface of each cover piece and interposed between the cylindrical projections, and an upper end portion of at least one of the cylindrical projections is machined to provide an enlarged diameter projection portion so as to preclude dislodging of the projection from the hole whereby the cover piece can positively connect the adjacent two buckets together.

Bucket cover attachment

A turbo machine rotor assembly which includes a turbine wheel having moving blade covers or connecting pieces connected to adjacent moving turbine blades. Each of the moving turbine blades includes a first ledge and second ledge at a leading edge and trailing edge side portions, respectively, of the tip of the blade with the first and second ledge portions extending substantially in tangential directions of the turbine wheel but in opposite directions to each other. One of the first and second ledges is provided with a through hole or aperture extending radially of the turbine wheel. The moving blade cover or connecting piece is provided with a pair of spaced pins receivable in the apertures of the first and second ledges for connecting the first ledge of one moving turbine blade and the second ledge of an adjacent moving turbine blade in such a manner that the upper surface of the cover contacts with the lower surfaces of the first and second ledges. One of the pins is loosely fitted in one aperture and the other pin is provided with a flared head portion for rotatably fixing the connecting piece between adjacent turbine blades. The moving blade cover can bear a large centrifuged force and does not constrain the torsions of the moving turbine blades during the rotation of the turbine wheel.

Turbomachine rotor assembly

The annular array of radially extending blades on the rotor of a rotary fluid machine are tied together at generally their mid portions by interlocking separate tying members and projection pairs, wherein each projection pair includes facing projections on adjacent blades of the array. The tying members and projections have mating bearing surfaces that will provide a tangential force as a result of wedging produced by the centrifugal force acting upon the tying members during rotation of the rotor at rated speed, without restraining individual twisting of the blades about their radial extent.

Apparatus for tying moving blades

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Hitachi, Japan

Tetsu Imai