Bearing bush of a turbocharger and turbocharger

Patent metadata

Field	Value
Publication number	US-10975727-B2
Application number	US-201816171144-A
Country	US
Kind code	B2
Filing date	Oct 25, 2018
Priority date	Oct 26, 2017
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

A bearing bush of a turbocharger for radially mounting a shaft of the turbocharger. The bearing bush on an inner surface facing the shaft to be mounted, which forms a running surface of the bearing bush, has a microstructuring of multiple cup-shaped recesses at least in sections. The recesses have a maximum depth.

First claim

What is claimed is:

1. A bearing bush of a turbocharger configured to radially mount a shaft of the turbocharger,
comprising:
an inner surface of the bearing bush facing the shaft to be mounted, which forms a running surface of the bearing bush;
at least one lubricating pocket arranged in the running surface of the bearing bush;
a radially extending lubricating passage configured to supply a lubricant;
a microstructuring arranged in the running surface of the bearing bush outside lubricating pockets configured as multiple cup-shaped recesses at least in sections of the inner surface of the bearing bush,
wherein the cup-shaped recesses have a maximum depth, such that:
s LW /t MAX ≥0.1 and/or

( h SS +t MAX )* v MAX /v SM ≤1800,

wherein:
s LW is an absolute clearance between the bearing bush and the shaft,
t MAX is a maximum depth of the cup-shaped recesses,
h SS is a minimum bearing clearance between the bearing bush and the shaft during operation,
v MAX is a maximum circumferential speed of the shaft, and
v SM is a kinematic viscosity of the lubricant utilised for lubrication.

2. The bearing bush according to claim 1 , wherein the microstructuring is provided at least into sections of the running surface of the bearing bush that are positioned in a region of a converging lubricating gap section between the bearing bush and the shaft.

3. The bearing bush according to claim 1 , wherein the depth of the cup-shaped recesses varies between respective cup-shaped recesses.

4. The bearing bush according to claim 1 , wherein in a radial viewing direction in plan view of the cup-shaped recesses a contour of a respective cup-shaped recesses varies.

5. The bearing bush according to claim 1 , wherein each of the cup-shaped recesses are contoured one of: rectangularly, triangularly, trapezoidally, and round.

6. The bearing bush according to claim 1 , wherein in an axial viewing direction a cross-sectional surface of the cup-shaped recesses varies.

7. The bearing bush according to claim 1 , wherein seen in a direction of rotation of the shaft, wherein at each respective point along a groove base of the cup-shaped recesses extends, linearly and/or curved with a constant and/or increasing and/or decreasing depth.

8. The bearing bush according to claim 1 , wherein the cup-shaped recesses of the microstructuring forms at least one cluster of equidistant or non-equidistant recesses, wherein the recesses in the respective cluster are linearly offset relative to one another.

9. The bearing bush according to claim 1 , wherein the at least one lubricating pocket comprises at least a lead in region a center region and a lead out region, wherein the center region has a greater redial depth than the lead in region and the lead out region.

10. The bearing bush according to claim 9 , wherein the lead in region and the lead out region have radially increasing depths that increase circumferentially towards the center region.

11. The bearing bush according to claim 1 , wherein the cup-shaped recesses of the microstructuring forms at least one cluster of equidistant or non-equidistant recesses, wherein the
recesses in the respective cluster are twisted relative to one another.

12. A turbocharger, comprising:
a shaft;
a turbine for expanding a first medium comprising:
a turbine rotor;

a compressor for compressing a second medium utilising energy extracted in the turbine during the expansion, comprising:
a compressor rotor that is coupled to the turbine rotor via the shaft; and

at least one bearing bush configured to radially mount the shaft, wherein
an inner surface of the bearing bush facing the shaft to be mounted, which forms a running surface of the bearing bush;
at least one lubricating pocket arranged in the running surface of the bearing bush;
a radially extending lubricating passage configured to supply a lubricant;
a microstructuring arranged in the running surface of the bearing bush outside lubricating pockets configured as multiple cup-shaped recesses at least in sections of the inner surface of the bearing bush,
wherein the cup-shaped recesses have a maximum depth, such that:
s LW /t MAX ≥0.1 and/or

( h SS +t MAX )* v MAX /v SM ≤1800,

wherein:
s LW is an absolute clearance between the bearing bush and the shaft,
t MAX is a maximum depth of the cup-shaped recesses,
h SS is a minimum bearing clearance between the bearing bush and the shaft during operation,
v MAX is a maximum circumferential speed of the shaft, and
v SM is a kinematic viscosity of the lubricant utilised for lubrication.

Assignees

• Man Energy Solutions Se

Inventors

• Brandt Sven
• HAAG Jan-Christoph
• Aurahs Lutz
• Heinz Christoph
• Benetschik Hannes

Classifications

• F16C33/10

  Construction relative to lubrication {(lubrication in general F16N)} · CPC title

• F02C7/06

  Arrangements of bearings (bearings F16C); Lubricating ({of turbo machines F01D25/18; of machines or} engines in general F01M) · CPC title

• F02B39/00 Primary

  Component parts, details, or accessories relating to, driven charging or scavenging pumps, not provided for in groups F02B33/00 - F02B37/00 · CPC title

• F01D25/22 Primary

  using working-fluid or other gaseous fluid as lubricant · CPC title

• F01D25/162 Primary

  Bearing supports · CPC title