Turbocharger thrust bearing debris trap

Patent metadata

Field	Value
Publication number	US-9382877-B2
Application number	US-201414520794-A
Country	US
Kind code	B2
Filing date	Oct 22, 2014
Priority date	Oct 22, 2014
Publication date	Jul 5, 2016
Grant date	Jul 5, 2016

Abstract

A turbocharger for an internal combustion engine includes a bearing housing and a rotating assembly arranged therein. The rotating assembly includes a shaft with a turbine wheel and a compressor wheel. The turbocharger also includes a thrust bearing assembly operatively connected to the shaft, lubricated by pressurized oil from the engine, and configured to transmit thrust forces developed by the turbine wheel to the bearing housing. The thrust bearing assembly includes a thrust plate having a first thrust face and a thrust washer having a second thrust face. An oil film is generated between the first and second thrust faces, and the first and second thrust faces rotate relative to each other and transmit the thrust forces to the bearing housing. The thrust plate and/or the thrust washer include a circumferential groove configured to trap oil-borne debris and minimize an amount of the debris in the oil film.

First claim

The invention claimed is:

1. A turbocharger for an internal combustion engine, the turbocharger comprising:
a bearing housing;
a rotating assembly arranged within the bearing housing and having a shaft with a turbine wheel configured to be driven by post-combustion gasses from the engine and with a compressor wheel configured to pressurize an ambient airflow for delivery to the engine; and
a thrust bearing assembly operatively connected to the shaft, lubricated by a pressurized oil from the engine, and configured to transmit thrust forces developed by the turbine wheel to the bearing housing;
wherein:
the thrust bearing assembly includes a thrust plate fixed to the bearing housing and having a first thrust face, and a thrust washer fixed to the shaft and having a second thrust face;
the pressurized oil generates an oil film between the first and second thrust faces;
the first thrust face is configured to rotate relative to the second thrust face and transmit the thrust forces to the bearing housing; and
at least one of the thrust plate and the thrust washer includes a circumferential groove configured to trap debris borne by the pressurized oil and minimize an amount of the debris present in the oil film.

2. The turbocharger of claim 1 , wherein the thrust plate is defined by an outer first diameter and the thrust washer is defined by an outer second diameter, wherein the outer first diameter is greater than the outer second diameter, wherein the first thrust face includes at least one thrust pad and the second thrust face includes at least one thrust surface, wherein the thrust pad and the thrust surface are each defined by an inner third diameter and by an outer fourth diameter that is smaller than the outer second diameter, and wherein the circumferential groove is arranged on a fifth diameter that is smaller than the outer second diameter.

3. The turbocharger of claim 2 , wherein the fifth diameter is greater than each of the inner third diameter and the outer fourth diameter.

4. The turbocharger of claim 2 , wherein the thrust plate includes the circumferential groove.

5. The turbocharger of claim 4 , wherein the thrust pad includes a plurality of individual thrust pads separated by respective radial slots, and the radial slots are in fluid communication with the circumferential groove.

6. The turbocharger of claim 5 , wherein the thrust plate defines a feed-hole at one of the radial slots, and wherein the pressurized oil enters the thrust bearing assembly via the feed-hole.

7. The turbocharger of claim 5 , wherein each of the plurality of individual thrust pads has a length, and wherein the length of one of the plurality of individual thrust pads is shorter than the length of each of the rest of the plurality of individual thrust pads, such that the debris is directed to the circumferential groove via the radial slots an away from the rest of the plurality of individual thrust pads.

8. The turbocharger of claim 2 , wherein the thrust washer includes the circumferential groove.

9. The turbocharger of claim 7 , wherein the thrust washer is configured to rotate with the shaft about an axis and the circumferential groove is centered on the axis.

10. The turbocharger of claim 1 , wherein the thrust plate is configured from one of brass and bronze and the thrust washer is configured from steel.

11. An internal combustion engine comprising:
an engine block defining a combustion chamber configured to receive an air-fuel mixture for combustion therein and configured to exhaust post-combustion gasses therefrom;
an oil pump configured to supply pressurized oil; and
a turbocharger configured to receive an airflow from the ambient and the post-combustion gasses from the combustion chamber, the turbocharger including:
a bearing housing;
a rotating assembly arranged within the bearing housing and having a shaft with a turbine wheel configured to be driven by the post-combustion gasses and a compressor wheel configured to pressurize the airflow for delivery to the combustion chamber; and
a thrust bearing assembly operatively connected to the shaft, lubricated by the pressurized oil, and configured to transmit thrust forces developed by the turbine wheel to the bearing housing;
wherein:
the thrust bearing assembly includes a thrust plate fixed to the bearing housing and having a first thrust face, and a thrust washer fixed to the shaft and having a second thrust face;
the pressurized oil generates an oil film between the first and second thrust faces;
the second thrust face is configured to rotate relative to the first thrust face and transmit the thrust forces to the bearing housing; and
at least one of the thrust plate and the thrust washer includes a circumferential groove configured to trap debris borne by the pressurized oil and minimize an amount of the debris present in the oil film.

12. The engine of claim 11 , wherein the thrust plate is defined by an outer first diameter and the thrust washer is defined by an outer second diameter, wherein the outer first diameter is greater than the outer second diameter, wherein the first thrust face includes at least one thrust pad and the second thrust face includes at least one thrust surface, wherein the thrust pad and the thrust surface are each defined by an inner third diameter and by an outer fourth diameter that is smaller than the outer second diameter, and wherein the circumferential groove is arranged on a fifth diameter that is smaller than the outer second diameter.

13. The engine of claim 12 , wherein the fifth diameter is greater than each of the inner third diameter and the outer fourth diameter.

14. The engine of claim 12 , wherein the thrust plate includes the circumferential groove.

15. The engine of claim 14 , wherein the thrust pad includes a plurality of individual thrust pads separated by respective radial slots, and the radial slots are in fluid communication with the circumferential groove.

16. The engine of claim 15 , wherein the thrust plate defines a feed-hole at one of the radial slots, and wherein the pressurized oil enters the thrust bearing assembly via the feed-hole.

17. The engine of claim 15 , wherein each of the plurality of individual thrust pads has a length, and wherein the length of one of the plurality of individual thrust pads is shorter than the length of each of the rest of the plurality of individual thrust pads, such that the debris is directed to the circumferential groove via the radial slots and away from the rest of the plurality of individual thrust pads.

18. The engine of claim 12 , wherein the thrust washer includes the circumferential groove.

19. The engine of claim 17 , wherein the thrust washer is configured to rotate with the shaft about an axis and the circumferential groove is centered on the axis.

20. The engine of claim 11 , further comprising a turbocharger oil line, wherein the engine block additionally defines an engine oil passage in fluid communication with the oil pump, wherein the turbocharger oil line is in fluid communication with the engine oil passage to thereby supply the pressurized oil from the oil pump to the thrust bearing assembly, and wherein the turbocharger oil line is characterized by an absence of an in-line oil filter configured to trap the debris borne by the pressurized oil.

Assignees

• Gm Global Tech Operations Inc

Inventors

• Begin Louis P
• Wu Ran
• Deng Dingfeng

Classifications

• F04D29/051

  Axial thrust balancing · CPC title

• F16C32/0651

  Details of the bearing area per se · CPC title

• F02M25/0706 Primary

  Mechanical Engineering · mapped topic

• F02M26/04 Primary

  with a single turbocharger · CPC title

• F04D29/0513

  hydrostatic; hydrodynamic thrust bearings · CPC title