Method for balancing turbine wheels of exhaust gas turbines, and balanced turbine wheel
AssigneeAccelleron Switzerland Ltd.
InventorsNico GEIST, Stephan SENN, Frank BURGER
Life of this patent
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Abstract
A method for balancing turbine wheels (10) of exhaust gas turbines and a balanced turbine wheel (10) are described herein. A turbine wheel of an exhaust gas turbine has a hub rear wall (15) which faces away from the fluid flow region and has a mass-removal indentation (13) and a marking bead (16).
Claims12
A method for balancing a turbine wheel (10) for an exhaust gas turbine, wherein the turbine wheel (10) is rotatable about its rotational axis (11) and has a hub (12) and a plurality of turbine blades attached to the hub (12) and arranged in a fluid flow region (14), wherein the hub has a hub rear wall (15) facing away from the fluid flow region (14) with a marking bead (16) running concentrically about the rotational axis (11), the method comprising:
- movement of an ellipsoidal material-removal tool relative to the turbine wheel (10) at a mass-removal position next to the marking bead (16);
- creation of a mass-removal indentation (13), asymmetric relative to the rotational axis (11), in the hub rear wall (15) for balancing the turbine wheel (10) by removal, by means of the material-removal tool, of hub material of the hub rear wall (15), next to the marking bead (16) and leaving the marking bead (16) intact.
The method as claimed in any of the preceding claims, wherein the mass-removal indentation (13) is made along a ring segment in the circumferential direction about the rotational axis (11).
The method as claimed in any of the preceding claims, furthermore comprising:
- determination of an imbalance of the turbine wheel;
- depending on the determined imbalance, setting of a material-removal profile for the mass-removal indentation (13);
- and
- creation of the mass-removal indentation (13) with the set material-removal profile.
The method as claimed in any of the preceding claims, furthermore comprising:
- definition of a removal-free hub test geometry;
- and
- calculation of a first hub quality parameter using a maximally removed hub test geometry as the defined removal-free hub test geometry, minus a maximum removal quantity from the hub rear wall of the removal-free hub test geometry;
- preferably optimization of the hub geometry by optimization of a hub optimization variable, calculated using the first hub quality parameter, by iterative changing of a hub test geometry between removal-free and maximally removed hub test geometry,
- wherein the removal of hub material at the hub rear wall (15) is limited by the maximum removal quantity.
A turbine wheel (10) for an exhaust gas turbine, wherein the turbine wheel (10) is rotatable about its rotational axis (11) and has
- a hub (12);
- and
- a plurality of turbine blades attached to the hub (12) and arranged in a fluid flow region (14), wherein the hub has a hub rear wall (15) facing away from the fluid flow region (14), wherein
- a mass-removal indentation (13), asymmetric relative to the rotational axis (11), is provided in the hub rear wall (15) for balancing the turbine wheel (10), wherein the mass-removal indentation (13) is configured as a concave depression in the hub rear wall (15) with a cross-sectional contour in the form of an ellipse segment, wherein the cross-sectional contour of the mass-removal indentation (13) is defined in a cross-sectional plane (Z-Z) containing the rotational axis (11), wherein
- the hub rear wall (15) furthermore has a marking bead (16) running concentrically to the rotational axis (11), wherein the marking bead (16) and the mass-removal indentation (13) are adjacent to one another without radially overlapping.
Dependencies are inferred from the claim text.