Moving blade for a turbomachine

#The invention relates to a moving blade, cast in one piece, for a turbomachine, in particular for a turbine or for a compressor.

#A moving blade of this type normally possesses an aerodynamically shaped profile body which, at its radially outer end, has an integrally molded shroud band which projects beyond the profile body in the circumferential direction. In the present patent application, the designations “radially”, “axial” and “circumferential direction” refer to the installation state of the moving blade, the axis of rotation of a rotor, to which the moving blade is fastened, running axially in this sense and thus defining the coordinate system of the moving blade.

#The shroud band formed at the moving blade tip, on the one hand, has a flow guide function, in that it prevents an undesirable flow around the profile body tips. On the other hand, the shroud band possesses a stabilizing function, since the dimensioning of the shroud band is such that, during operation, shroud bands of moving blades adjacent to one another in the circumferential direction are supported mutually one on the other and thereby reduce oscillations and vibrations of the moving blades.

#A preferred exemplary embodiment of the invention is illustrated in the drawings and is explained in more detail in the following description, identical reference symbols relating to identical or functionally identical or similar components. In the drawings, in each case diagrammatically,

#FIG. 1 shows an axial section through a moving blade according to the invention in the region of a fin along the sectional lines I in FIG. 2,

#FIG. 2 shows a section through the fin in the circumferential direction along the sectional lines II in FIG. 1.

#According to FIGS. 1 and 2, a moving blade 1 according to the invention of a turbomachine, in particular a turbine or a compressor, possesses a profile body 2 which is shaped aerodynamically and, during operation, has a flow passing around it. In FIG. 2, a tip profile formed at the tip of the profile body 2 is illustrated by a broken line and is designated by 3. A foot profile present on the radially inner foot of the profile body is designated by 4. As may be gathered from the run of the profile along the profile body 2, the latter is twisted. The radial direction is in this case symbolized in FIG. 1 by an arrow 7.

#The profile body 2 has integrally molded on it, at its radially outer end, a shroud band 5 which, on the one hand, completely covers the tip profile 3 and, on the other hand, projects beyond the profile body 2 in the circumferential direction approximately centrally with respect to the profile body 2. The circumferential direction is in this case symbolized in FIG. 2 by an arrow 6. To complete the reference system, FIGS. 1 and 2 additionally illustrate the axial direction by means of an arrow 8.

#The projecting regions of the shroud band 5 are designed in FIG. 2 by 9 and 10 and serve for flow guidance when the moving blade 1 is in operation, in that they obstruct an undesirable flow around the tip of the profile body 2. Furthermore, these regions 9, 10 of the shroud band 5 are dimensioned such that, when the moving blade is in operation, they cooperate with matching regions 9, 10 of adjacent moving blades 1 in order to stabilize the moving blades 1. At the latest when the moving blades 1 are in operation, that is to say with turbine rotor or compressor rotor rotating, the shroud bands 5 of adjacent moving blades 1 come to bear on one another at the regions 9, 10 projecting in the circumferential direction, for which purpose corresponding bearing surfaces 11 are formed at the regions 9, 10. As a result, on the one hand, an additional twisting of the profile body 2 during operation is limited. On the other hand, the mutual support damps the formation of oscillations or increases the frequency of the latter.