Turbocharger with thrust bearing providing combined journal and thrust bearing functions

Patent metadata

Field	Value
Publication number	US-9797303-B2
Application number	US-201314391108-A
Country	US
Kind code	B2
Filing date	Apr 1, 2013
Priority date	Apr 10, 2012
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

Turbochargers typically have separate hydrodynamic journal and thrust bearings. A turbocharger thrust bearing for a turbocharger is provided that merges the function of a journal bearing into a thrust bearing while maintaining the thrust bearing function to produce a turbocharger with a reduced axial space envelope. Such a thrust bearing includes a bore contoured to have a plurality of taper-land pairs distributed circumferentially about the bore. As a result, the axial length of the turbocharger bearing housing and shaft can be reduced.

First claim

The invention claimed is:

1. A turbocharger thrust bearing ( 52 ) comprising:
a main body ( 55 ) having a bore ( 72 ), the bore ( 72 ) having a center axis ( 84 ) and an associated circumferential direction about the center axis ( 84 ), the bore ( 72 ) being contoured to provide a plurality of taper-land pairs ( 78 ) distributed in the circumferential direction about the bore ( 72 ), each taper-land pair ( 78 ) including a taper portion ( 80 ) transitioning to a land portion ( 82 ), each taper portion ( 80 ) beginning at a first radial distance from the center axis ( 84 ) and extending generally in the circumferential direction therefrom to the land portion ( 82 ), the land portion ( 82 ) extending generally in the circumferential direction at a substantially constant second radial distance from the center axis ( 84 ), the second radial distance being less than the first radial distance, and wherein the main body ( 55 ) includes an array of ramps ( 54 ) and lands ( 56 ) provided about an axially facing side ( 58 ) of the main body ( 55 ).

2. The turbocharger thrust bearing of claim 1 , further including a plurality of grooves ( 60 ) formed in the main body ( 55 ), wherein the grooves ( 60 ) open to the bore ( 72 ), wherein each of the plurality of taper-land pairs ( 78 ) is provided between a respective neighboring pair of grooves ( 60 ).

3. The turbocharger thrust bearing of claim 1 , wherein the difference between the first radial distance and the second radial distance is from about 0.05 millimeters to about 0.1 millimeters.

4. The turbocharger thrust bearing of claim 1 , wherein each taper-land pair ( 78 ) has an associated arc length (Θ TL ), and wherein at least about 50% of the arc length (Θ TL ) of each taper-land pair ( 78 ) is comprised of the taper portion ( 80 ).

5. The turbocharger thrust bearing of claim 4 , wherein the taper portion ( 80 ) comprises at least about 70% of the arc length (Θ TL ) of each taper-land pair ( 78 ).

6. The turbocharger thrust bearing of claim 1 , wherein the plurality of taper-land pairs ( 80 ) is substantially equally spaced in the circumferential direction.

7. The turbocharger thrust bearing of claim 1 , wherein the radial distance of the taper portion ( 80 ) from the center axis ( 84 ) decreases substantially continuously from the first radial distance to the second radial distance.

8. The turbocharger thrust bearing according of claim 2 further comprising an oil channel ( 66 ) and at least one oil transfer gallery ( 68 ) in fluid communication with the oil channel ( 66 ), wherein the oil channel ( 66 ) surrounds at least a portion of the main body ( 55 ), and wherein the at least one oil transfer gallery ( 68 ) is in fluid communication with the main body ( 55 ).

9. A turbocharger ( 50 ) comprising:
a bearing housing ( 23 );
a thrust bearing ( 52 ) provided in the bearing housing ( 23 ), the thrust bearing ( 52 ) including a bore ( 72 ) with a center axis ( 84 ) and an associated circumferential direction about the center axis ( 84 ), the bore ( 72 ) being contoured to provide a plurality of taper-land pairs ( 78 ) distributed in the circumferential direction about the bore ( 72 ), each taper-land pair ( 78 ) including a taper portion ( 80 ) transitioning to a land portion ( 82 ), each taper portion ( 80 ) beginning at a first radial distance from the center axis ( 84 ) and extending generally in the circumferential direction therefrom to the land portion ( 82 ), the land portion ( 82 ) extending generally in the circumferential direction at a substantially constant second radial distance from the center axis ( 84 ), the second radial distance being less than the first radial distance; and
a shaft ( 20 ) having an associated axis of rotation ( 21 ) and having a direction of rotation about the axis ( 21 ), at least a portion of the shaft ( 20 ) being received in the bore ( 72 ), the taper-land pairs ( 78 ) being arranged such that the taper portion ( 80 ) precedes the land portion ( 82 ) in the direction of rotation, wherein the shaft ( 20 ) has a compressor region ( 53 ) and a turbine region ( 51 ), and wherein the turbine region ( 51 ) of the shaft ( 20 ) is supported by at least one journal bearing ( 26 ), and wherein the compressor region ( 53 ) of the shaft ( 20 ) is not supported by a journal bearing.

10. The turbocharger of claim 9 , further including a plurality of grooves ( 60 ) formed in the main body ( 55 ), wherein the grooves ( 60 ) open to the bore ( 72 ), wherein each of the plurality of taper-land pairs ( 78 ) is provided between a respective neighboring pair of grooves ( 60 ).

11. The turbocharger of claim 9 , wherein the difference between the first radial distance and the second radial distance is from about 0.05 millimeters to about 0.1 millimeters.

12. The turbocharger of claim 9 , wherein each taper-land pair ( 78 ) has an associated arc length (Θ TL ), and wherein at least about 50% of the arc length (Θ TL ) of each taper-land pair ( 78 ) is comprised of the taper portion ( 80 ).

13. The turbocharger of claim 12 , wherein the taper portion ( 80 ) comprises at least about 70% of the arc length (Θ TL ) of each taper-land pair ( 78 ).

14. The turbocharger of claim 9 , wherein the plurality of taper-land pairs ( 78 ) is substantially equally spaced in the circumferential direction.

15. The turbocharger of claim 9 , wherein the radial distance of the taper portion ( 80 ) from the center axis ( 84 ) decreases substantially continuously from the first radial distance to the second radial distance.

Assignees

• Borgwarner Inc

Inventors

• Ward Daniel N

Classifications

• F16C17/26

  Systems consisting of a plurality of sliding-contact bearings · CPC title

• F02B39/00

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

• F02B37/12

  Control of the pumps · CPC title

• F04D25/024

  the driving means being assisted by a power recovery turbine · CPC title

• F01D25/186

  for sliding contact bearing · CPC title