Turbocharger with predetermined breaking point for an internal combustion engine

Patent metadata

Field	Value
Publication number	US-11060453-B2
Application number	US-201916663732-A
Country	US
Kind code	B2
Filing date	Oct 25, 2019
Priority date	Apr 28, 2017
Publication date	Jul 13, 2021
Grant date	Jul 13, 2021

Abstract

Disclosed is a turbocharger for an internal combustion engine, having a bearing housing. A turbocharger rotor is mounted to be rotatable in the bearing housing about the rotor axis of rotation of its rotor shaft, wherein a turbine wheel is arranged for conjoint rotation on the rotor shaft and in a turbine housing fixed on the bearing housing. Between the rotor shaft and the bearing housing, an oil seal for sealing the bearing housing with respect to the turbine housing is arranged between the turbine wheel and a radial bearing associated with the turbine wheel in order to seal the bearing housing with respect to the turbine housing. A predetermined breaking point is formed for the turbocharger rotor of the turbocharger which lies in a breaking point region and extends axially between the turbine wheel back and an axial end, facing the turbine wheel back, of the rotor-shaft oil seal.

First claim

The invention claimed is:

1. A turbocharger for an internal combustion engine, comprising:
a bearing housing having a compressor side and a turbine side and a bearing housing interior,
a turbine housing, which is fixed mechanically on the bearing housing on the turbine side;
a turbocharger rotor, which has a rotor shaft and a turbine wheel, wherein the rotor shaft of the turbocharger rotor is rotatably mounted in the bearing housing by means of at least two radial bearings, and the turbine wheel is arranged for conjoint rotation on a turbine end of the rotor shaft and in the turbine housing, and
at least one turbine-side rotor-shaft oil seal for sealing the bearing housing interior with respect to the turbine housing, the seal being arranged on the rotor shaft and between the rotor shaft and the bearing housing, wherein, axially in relation to a rotor axis of rotation, the turbine-side rotor-shaft oil seal is arranged on the rotor shaft between a turbine wheel back, which faces the bearing housing, and a radial bearing closest to the turbine wheel,
wherein a predetermined breaking point is formed for the turbocharger rotor, the breaking point lying in a breaking point region which, in relation to the rotor axis of rotation, extends axially between the turbine wheel back and an axial end, facing the turbine wheel back, of the turbine-side rotor-shaft oil seal which is arranged furthest away from the turbine wheel, the rotor shaft breaks at the predetermined breaking point in the event of a failure.

2. The turbocharger as claimed in claim 1 , wherein there is a weld seam in the region of the predetermined breaking point, by means of which weld seam the turbine wheel is connected to the rotor shaft.

3. The turbocharger as claimed in claim 1 , wherein, axially in relation to the rotor axis of rotation, the predetermined breaking point is arranged at that point of the breaking point region of the rotor shaft which is subject to a highest stress during operation of the turbocharger.

4. The turbocharger as claimed in claim 3 , wherein there is a weld seam in the region of the predetermined breaking point, by means of which weld seam the turbine wheel is connected to the rotor shaft.

5. The turbocharger as claimed in claim 3 , wherein a predetermined rubbing contact point between the rotor shaft and the bearing housing is provided in the region of the predetermined breaking point, wherein a smallest radial spacing between the rotor shaft and a rotor shaft opening of the bearing housing is provided in a region of the rubbing contact point, with the result that, during normal operation, the rotor shaft runs without contact within the rotor shaft opening and, in the event of failure of the radial bearings, initially rubs against the bearing housing in the region of the rubbing contact point.

6. The turbocharger as claimed in claim 1 , wherein, axially in relation to the rotor axis of rotation, the predetermined breaking point is arranged between the turbine wheel back and the axial end, facing the turbine wheel back, of the turbine-side rotor-shaft oil seal which is closest to the turbine wheel back.

7. The turbocharger as claimed in claim 6 , wherein there is a weld seam in the region of the predetermined breaking point, by means of which weld seam the turbine wheel is connected to the rotor shaft.

8. The turbocharger as claimed in claim 6 , wherein a predetermined rubbing contact point between the rotor shaft and the bearing housing is provided in the region of the predetermined breaking point, wherein a smallest radial spacing between the rotor shaft and a rotor shaft opening of the bearing housing is provided in a region of the rubbing contact point, with the result that, during normal operation, the rotor shaft runs without contact within the rotor shaft opening and, in the event of failure of the radial bearings, initially rubs against the bearing housing in the region of the rubbing contact point.

9. The turbocharger as claimed in claim 1 , wherein, axially in relation to the rotor axis of rotation, the predetermined breaking point is arranged in an immediate vicinity of the turbine wheel back of the turbine wheel.

10. The turbocharger as claimed in claim 9 , wherein there is a weld seam in the region of the predetermined breaking point, by means of which weld seam the turbine wheel is connected to the rotor shaft.

11. The turbocharger as claimed in claim 9 , wherein a predetermined rubbing contact point between the rotor shaft and the bearing housing is provided in the region of the predetermined breaking point, wherein a smallest radial spacing between the rotor shaft and a rotor shaft opening of the bearing housing is provided in a region of the rubbing contact point, with the result that, during normal operation, the rotor shaft runs without contact within the rotor shaft opening and, in the event of failure of the radial bearings, initially rubs against the bearing housing in the region of the rubbing contact point.

12. The turbocharger as claimed in claim 9 , wherein the turbine wheel has a cylindrical hub connection piece on the side of the turbine wheel facing the rotor shaft, the connection piece having a transitional region, embodied as a fillet, to the turbine wheel back, wherein the predetermined breaking point is arranged in the transitional region.

13. The turbocharger as claimed in claim 1 , wherein a predetermined rubbing contact point between the rotor shaft and the bearing housing is provided in the region of the predetermined breaking point, wherein a smallest radial spacing between the rotor shaft and a rotor shaft opening of the bearing housing is provided in a region of the rubbing contact point, with the result that, during normal operation, the rotor shaft runs without contact within the rotor shaft opening and, in the event of failure of the radial bearings, initially rubs against the bearing housing in the region of the rubbing contact point.

14. The turbocharger as claimed in claim 13 , wherein the turbine-side rotor-shaft oil seal is formed by at least one piston ring arranged in an encircling piston ring groove between two piston ring lands, wherein, in relation to the rotor axis of rotation, the piston ring land which is closer to the turbine wheel back has a smallest radial gap relative to the rotor shaft opening of the bearing housing in order to form the rubbing contact point.

15. A turbocharger for an internal combustion engine, comprising:
a bearing housing having a compressor side, a turbine side and a bearing housing interior,
a turbine housing fixed mechanically on the bearing housing on the turbine side thereof;
a turbocharger rotor comprising a rotor shaft and a turbine wheel, wherein the rotor shaft is rotatably mounted in the bearing housing by at least two radial bearings, and the turbine wheel is arranged for conjoint rotation with the rotor shaft on a turbine end of the rotor shaft and in the turbine housing, and
at least one turbine-side rotor-shaft oil seal configured to seal the bearing housing interior with respect to the turbine housing, the seal being arranged on the rotor shaft and between the rotor shaft and the bearing housing, wherein, axially in relation to a rotor axis of rotation, the turbine-side rotor-shaft oil seal is arranged on the rotor shaft between a turbine wheel back, which faces the bearing housing, and a radial bearing of the at least two radial bearings that is closest to the turbine wheel,
wherein a predetermined breaking point is formed for the turbocharger rotor, the breaking point lying in a breaking point region which, in relation to the rotor axis of rotat

Assignees

• Vitesco Tech Gmbh

Inventors

• Böning Ralf
• Klaus Michael
• Frankenstein Dirk
• Lehmayr Bernhard
• Ferling Bruno

Classifications

• Y02T10/12

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• F01D21/10

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• F05D2230/237

  Brazing · CPC title

• F05D2230/238

  Soldering · CPC title

• F01D5/025

  Fixing blade carrying members on shafts (attachment of a member on a shaft in general F16D1/06; for non-positive displacement pumps F04D29/00) · CPC title