Asea Brown Boveri Inc.

Abb Alstom Power (Schweiz) Ag

Dieter Freuschle

Siegfried Hohmann

Moving blades of a fluid-flow machine are fastened in a circumferential slot on the rotor by means of blade roots. For the installation of the last moving blade, a gap is provided between the first and penultimate blade. After the latter has been fitted, a residual gap remains in the circumferential slot, and this residual gap is filled by means of whole intermediate pieces and halved intermediate pieces (,), which are arranged between the moving-blade roots. According to the invention, the inner sides (,) of the halved intermediate pieces (,), which inner sides (,) face the center of the circumferential slot, are of hook-shaped design. In this case, the inner side (,) of one half (,) of a halved intermediate piece forms the geometric negative of the inner side (,) of the other half (,) of the halved intermediate piece. As a result, the two halves (,) can be connected to one another in a positive-locking manner. Axial forces which act on the side walls of the circumferential slot are reduced by this connection, so that the cross section of the halved intermediate pieces (,) can be produced in a rectangular form and consequently more cost-effectively.

Fastening of moving blades of a fluid-flow machine

An arrangement for controlled admission to a nozzle assembly of axial flow extraction steam turbines consists essentially of a control valve located upstream of the nozzle assembly and having two inlet windows for the working medium and of a duct element located between the control valve and the nozzle assembly. The duct element is provided with a plurality of inlet flow ducts which connect the inlet windows of the control valve to the nozzles of the nozzle assembly. The control valve is rotatable by 180.degree. in the peripheral direction for increasing the opening or closing of the inlet flow ducts.

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Waldshut, Germany

Dieter Freuschle