Turbocharger Turbine Rotor and Turbocharger

Abstract

A turbocharger turbine rotor includes a rotor basic body, and moving blades configured without an outer shroud. The moving blades, forming a defined curvature region, merge into the rotor basic body with a defined, constant or variable curvature radius r.sub.f. On a first group of first moving blades, the following relationship applies to the curvature radius of the curvature region of the first moving blades: 2.5%r.sub.f1*100/l10%, wherein r.sub.f1 is the constant or variable curvature radius of the curvature region of the first moving blades and l the length of the first moving blades on a flow trailing edge. On a second group of second moving blades, the curvature radius r.sub.f2 of the curvature region of the second moving blades deviates from the curvature radius rf1 of the curvature region of the first moving blades on the damping side in a defined manner.

Claims

1. A turbocharger turbine rotor (1), comprising: a rotor basic body (2); and a plurality of moving blades (3) integrally formed on the rotor basic body (2), wherein the plurality of moving blades (3) are configured without an outer shroud, wherein the plurality of moving blades (3), forming a defined curvature region (4), merge into the rotor basic body (2) with a defined constant or variable curvature radius r.sub.f, wherein on a first group of first moving blades of the plurality of moving blades (3) the following relationship applies to the curvature radius of the curvature region (4) of the first moving blades (3):
2.5%r.sub.f1*100/l10%, wherein r.sub.f1 is a constant or variable curvature radius of the curvature region of the first moving blades and l is a length of the first moving blades on a flow trailing edge (6), and wherein on a second group of second moving blades of the plurality of moving blades (3) a curvature radius r.sub.f2 of the curvature region (4) of the second moving blades (3) deviates from the curvature radius r.sub.f1 of the curvature region (4) of the first moving blades (3) on the damping side.

2. The turbocharger turbine rotor according to claim 1, wherein the curvature radius r.sub.f2 of the curvature region (4) of the respective second moving blades (3) deviates from the curvature radius r.sub.f1 of the curvature region (4) of the first moving blades (3) such that the curvature radius r.sub.f2 of the curvature region (4) of the respective second moving blades (3) does not satisfy the relationship for the curvature radius r.sub.f1 of the curvature region (4) of the first moving blades (3).

3. The turbocharger turbine rotor according to claim 2, wherein on the respective second moving blades (3) the curvature radius r.sub.f2 of the curvature region (4) of the second moving blades (3) deviates from the curvature radius r.sub.f1 of the curvature region (4) of the first moving blades (3) in a damping-optimized manner.

4. The turbocharger turbine rotor according to claim 3, wherein in a case in which the curvature radius r.sub.f1 on the first moving blades is constant, the following applies to the curvature radius r.sub.f2 of the respective second moving blade (3):
120%r.sub.f2*100/r.sub.f1300%.

5. The turbocharger turbine rotor according to claim 4, wherein in a case in which the curvature radius r.sub.f1 on the first moving blades is constant, the curvature radius r.sub.f2 on the respective second moving blade is also constant.

6. The turbocharger turbine rotor according to claim 5, wherein with a moving blade having a constant curvature radius in each position of the curvature region (4), in the region of a flow leading edge (5), the curvature radius in the region of the flow trailing edge (6) and in regions of sides (7, 8) extending between the flow leading edge and the flow trailing edge, is equal in size.

7. The turbocharger turbine rotor according to claim 3, wherein in a case in which the curvature radius r.sub.f1 on the first moving blades is variable, the following applies to the curvature radius r.sub.f2 of the respective second moving blade (3):
130%r.sub.f2*100/r.sub.f1400%.

8. The turbocharger turbine rotor according to claim 7, wherein in particular in a case in which the curvature radius r.sub.f1 on the first moving blades is variable, the curvature radius r.sub.f2 on the respective second moving blade is also variable.

9. The turbocharger turbine rotor according to claim 8, wherein with a moving blade having a variable curvature radius in the region of a flow leading edge (5) and/or in the region of the flow trailing edge (6) and/or in regions of sides (7, 8) extending between the flow leading edge and the flow trailing edge, the curvature radius is different in size.

10. The turbocharger turbine rotor according claim 1, wherein the first group of first moving blades comprises multiple moving blades and the second group of second moving blades comprises at least one moving blade.

11. The turbocharger turbine rotor according to claim 1, wherein the percentage of the second moving blades in the total number of the moving blades is between 15% and 60%.

12. A turbocharger comprising: a turbine configured to expand a first medium; and a compressor configured to compress a second medium utilizing energy extracted in the turbine during the expansion of the first medium, wherein the turbine comprises a turbine housing and the turbine rotor according to claim 1, wherein the compressor comprises a compressor housing and a compressor rotor that is coupled to the turbine rotor via a shaft, wherein the turbine housing and the compressor housing are each connected to a bearing housing arranged therebetween, in which the shaft is mounted.

13. The turbocharger according to claim 12, wherein the turbine rotor is an axial turbine rotor.

14. The turbocharger according to claim 12, wherein the turbine rotor is a radial turbine rotor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Exemplary embodiments of the invention are explained in more detail by way of the drawings without being restricted to this. In the drawings:

[0016] FIG. 1 is a perspective view of a turbocharger turbine rotor of an axial turbine according to the invention;

[0017] FIG. 2 shows the detail II of FIG. 1;

[0018] FIG. 3 is a perspective view of a turbocharger turbine rotor of a radial turbine according to the invention;

[0019] FIG. 4 shows the detail IV of FIG. 3; and

[0020] FIG. 5 is a detail of FIG. 2 or 4.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0021] The invention relates to turbocharger turbine rotor and to a turbocharger having such a turbocharger turbine rotor.

[0022] A turbocharger comprises a turbine and a compressor. The turbine serves for expanding a first medium, in particular for expanding exhaust gas of an internal combustion engine, wherein during the expansion of the first medium energy is extracted. The compressor of the turbocharger serves for compressing a second medium, in particular for compressing charge air, utilizing energy extracted in the turbine.

[0023] The turbine of the turbocharger comprises a turbine housing and a turbine rotor that is rotatably mounted in the turbine housing. The compressor of the turbocharger comprises a compressor housing and a compressor rotor that is rotatably mounted in the compressor housing. Turbine rotor and compressor rotor of the turbocharger are coupled via a shaft, which is rotatably mounted in a bearing housing, wherein the bearing housing is connected both to the turbine housing and also to the compressor housing.

[0024] The invention relates to details of the turbine rotor of a turbocharger.

[0025] FIG. 1 shows a perspective view of a turbocharger turbine rotor 1, which comprises a rotor basic body 2 and moving blades 3 that are integrally formed on the rotor basic body 2. FIG. 2 shows the detail II of FIG. 1. Because of the axial flow direction in the turbocharger turbine rotor, this design is referred to as turbocharger axial turbine rotor. The flow direction of the turbocharger axial turbine rotor is visualized in FIG. 1, 2 by an arrow S.

[0026] FIG. 3 shows a perspective view of a turbocharger turbine rotor 1 which is subjected to an inflow directed radially to the rotor axis. The turbocharger turbine rotor 1 of FIG. 3 also comprises a rotor basic body 2 and moving blades 3 that are integrally formed on the rotor basic body 2. FIG. 4 shows the detail IV of FIG. 3. The turbocharger turbine rotor of this design is referred to as turbocharger radial turbine rotor. The flow direction of the turbocharger radial turbine rotor is in turn visualized in FIG. 3, 4 by an arrow S.

[0027] The moving blades 3 of the respective turbocharger turbine rotor 1 merge into the rotor basic body 2 inside forming a defined curvature region 4, wherein this curvature region 4 is also referred to as fillet. On the outside, the moving blades 3 are formed without a shroud.

[0028] The curvature regions 4 of the moving blades, with which the moving blades 3 merge into the rotor basic body 2, are characterized by a curvature radius r.sub.f. See FIG. 5. This curvature radius r.sub.f can be a constant curvature radius r.sub.f or a variable curvature radius r.sub.f.

[0029] The moving blades 3 have a defined length l in the radial direction a flow trailing edge 6, wherein all moving blades 3 preferentially have the identical length l in the radial direction at the flow trailing edge 6.

[0030] The moving blades 3 form a first group of first moving blades and a second group of second moving blades 3. The first group of first moving blades comprises multiple moving blades 3 and the second group of second moving blades comprises at least one moving blade 3.

[0031] The following relationship (1):

0.025r.sub.f1/l0.1 or 2.5%r.sub.f1*100/l10%(1) [0032] applies on the first group of first moving blades 3 for the curvature radius r.sub.f of the curvature region 4 of the first moving blades 3, which is referred to as r.sub.f1 [0033] wherein [0034] r.sub.f1 is the constant or variable curvature radius of the curvature region of the first moving blades, [0035] l is the length of the first moving blades at a flow trailing edge.

[0036] On the second group of second moving blades 3 the curvature radius r.sub.f of the curvature region 4 of the second moving blades 3, which is referred to as r.sub.f2, deviates from the curvature radius r.sub.f1 of the curvature region 4 of the first moving blades 3 on the damping side, namely in a damping-optimized manner in order to provide, subject to providing a targeted frequency detuning between the moving blades 3 of the turbocharger turbine rotor 1, optimum vibration damping characteristics of the turbocharger turbine rotor 1 so that the turbocharger turbine rotor 1 can be continuously operated in all operating points. The curvature radius r.sub.f2 of the curvature region 4 of the respective second moving blade 3 deviates from the curvature radius r.sub.f1 of the curvature region 4 of the first moving blades 3 such that the curvature radius r.sub.f2 of the curvature region 4 of the respective second moving blades 3 does not satisfy the above relationship (1) for the curvature radius r.sub.f1 of the curvature region 4 of the first moving blades 3.

[0037] The number of the second moving blades of the second group amounts to between 15% and 60% of the total number of first and second moving blades 3 of the first and second group.

[0038] Each moving blade 3 has a flow leading edge 5, the flow trailing edge 6, and flow-guiding sides or surfaces 7, 8 extending between the flow leading edge 5 and the flow trailing edge 6, wherein one of these flow-guiding surfaces is embodied as suction side and the other one of these flow-guiding surfaces as pressure side. The flow leading edge 5, the flow trailing edge 6 and these flow-guiding surfaces 7, 8 extend into the curvature region 4 of the respective moving blade 3.

[0039] In each position of the curvature region 4, i.e., in the region of the flow leading edge 5, in the region of the flow trailing edge 6 and in the regions of the flow-guiding surfaces 7, 8 extending between the flow leading edge 5 and the flow trailing edge 6, a curvature radius r.sub.f is formed.

[0040] In a moving blade with constant curvature radius, the curvature radius in each position of the curvature region 4, i.e., in the region of the flow leading edge 5, in the region of the flow trailing edge 6 and in regions of the sides 7 and 8 extending between the flow leading edge and the flow trailing edge is identical in size. Then, a constant curvature radius extends in this case roundabout the entire curvature region 4. This type of curvature radius is referred to as constant curvature radius of the respective moving blade.

[0041] In a moving blade with variable curvature radius, the curvature radius in the region of a flow leading edge 5 and/or in the region of the flow trailing edge 6 and/or in regions of the sides 7 and 8 extending between the flow leading edge and the flow trailing edge differs in size. In this case, the curvature radius, emanating from the respective flow leading edge 5, varies in the direction of the respective flow trailing edge 6. This type of curvature radius is referred to as variable curvature radius of the respective moving blade.

[0042] Regardless of whether the first moving blades 3 of the first group have a constant or variable curvature radius in the respective curvature region 4, the relationship (1), i.e.:

0.025r.sub.f1/l0.1 or 2.5%r.sub.f1*100/l10%

[0043] applies to the curvature radius of the first moving blades 3 in each position of the curvature region.

[0044] In particular when the curvature radius r.sub.f1 on the first moving blades 3 in the curvature region 4 is constant, the following relationship (2):

r.sub.f2=r.sub.f1*1.2 to 3 or 1.2r.sub.f2/r.sub.f13 or 120%r.sub.f2*100/r.sub.f1300%(2)

preferentially applies to the curvature radius r.sub.f2 of the curvature region 4 of the respective second moving blade 3.

[0045] In particular when the curvature radius r.sub.f1 on the first moving blades is constant, the curvature radius r.sub.f2 on the or each second moving blade is preferentially also constant.

[0046] In particular when the curvature radius r.sub.f1 on the first moving blades is variable, the following relationship (3):

r.sub.f2=r.sub.f1*1.3 to 4 or 1.3r.sub.f2/r.sub.f14 or 130%r.sub.f2*100/r.sub.f1400%(3)

[0047] preferentially applies to the curvature radius r.sub.f2 of the curvature region 4 of the respective second moving blade 3.

[0048] In particular when the curvature radius r.sub.f1 on the first moving blades is variable, the curvature radius r.sub.f2 on the or each second moving blade is preferentially also variable.

[0049] With the invention present here a turbocharger turbine rotor for a turbocharger can be provided, which is embodied as an integrally bladed turbine rotor without outer shroud and has a resonance-proof blading, so that the turbine, namely the turbocharger turbine rotor, can be safely operated with optimal damping characteristics in all operating points.

[0050] A turbocharger according to the invention comprises a turbine for expanding a first medium and a compressor for compressing a second medium utilizing energy extracted in the turbine during expansion of the first medium. The turbine comprises a turbine housing and a turbine rotor subjected to a flow. The compressor comprises a compressor housing and a compressor rotor that is coupled to the turbine rotor via a shaft. The turbine housing and the compressor housing are each connected to a bearing housing arranged between the same, in which the shaft is mounted. The turbine rotor is configured according to the invention as described above. The turbine rotor can be an axial turbine rotor or a radial turbine rotor.

LIST OF REFERENCE NUMBERS

[0051] 1 Turbine rotor [0052] 2 Rotor basic body [0053] 3 Moving blade [0054] 4 Curvature region [0055] 5 Flow leading edge [0056] 6 Flow trailing edge [0057] 7 Surface [0058] 8 Surface