The invention relates to a turbine wheel according to the preamble of claim 1 and to a method for the production thereof, according to the preamble of claim 3.
The so-called rotor of a turbocharger has a turbine wheel and the turbocharger shaft which can be connected to the turbine wheel via a weld peg arranged on the back of the turbine wheel. For said connection, it is possible for the shaft and the turbine wheel to be connected to one another using a welding process (for example friction welding or electron beam welding). A turbine wheel TR for such a welding process is illustrated in highly simplified schematic form in
It is therefore an object of the present invention to provide a turbine wheel according to the preamble of claim 1 and to a method for the production thereof according to the preamble of claim 3, wherein it should be possible to avoid an additional machining step for creating an undercut in the transition region between the weld peg and the wheel back of the turbine wheel.
Said object is achieved by means of the features of claim 1 and of claim 3.
The invention achieves the stated object in a surprisingly simple manner in that, by means of a suitable casting process, the undercut can be provided already in the turbine wheel blank, such that after the casting process, only that region of the weld peg which up to the transition region, which is already provided with the undercut in any case, of the turbine wheel blank need be mechanically machined. Consequently, in contrast to the prior art, a further machining step is eliminated. Furthermore, after the casting process, that region of the weld peg which is machined for example by means of a grinding disk forms a continuous transition region with the undercut which is integrated during the casting process, which continuous transition region has a positive effect on the strength of the rotor composed of turbine wheel and rotor shaft.
The subclaims relate to advantageous refinements of the invention.
Further details, features and advantages of the invention will emerge from the following description of exemplary embodiments on the basis of the drawing, in which:
After the casting of the turbine wheel blank 2, the latter is machined as far as the arrow “End of grinding zone”, wherein that region 6 of the dashed line which extends as far as the arrow “End of grinding zone” is removed for example by means of a grinding process, so as to yield a contour of the points 7 and 8 of the line visible in
The undercut in the transition region 5 can accordingly be seen more clearly from
The design of the undercut 4 is even clearer in comparison with the prior art, which is illustrated once again in
Accordingly, the method according to the invention for producing a turbine wheel 1 is restricted to the casting of the turbine wheel blank 2 which is provided with the weld peg Z and the turbine wheel back 3, with the above-explained undercut 4 being produced in the transition region 5 during the casting of the turbine wheel blank 2.
Accordingly, only the above-explained region 6 need be machined after the casting in order to produce the finished turbine wheel 1 from the blank 2.
In addition to the above written disclosure, to complete the latter, reference is hereby explicitly made to
Number | Date | Country | Kind |
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102010008555.3 | Feb 2010 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US11/23868 | 2/7/2011 | WO | 00 | 8/3/2012 |