PISTON WITH PIN BORE LUBRICATION FEATURES

• US 20080250922A1
• Filed: 01/25/2008
• Published: 10/16/2008
• Est. Priority Date: 04/10/2007
• Status: Active Grant

• Current Assignee: Federal-Mogul World Wide LLC (Apollo Global Management, Inc.)
• Original Assignee: Federal-Mogul Worldwide Incorporated (Apollo Global Management, Inc.)
• Inventors: Wilkerson, Jeffery D., Hayes, James Russell, Overbey, John David, Dowdy, Gary D.
• Granted Patent: US 7,845,269 B2
• Time in Patent Office: Days
• US Class Current: 92/158
• CPC Class Codes: F01M 11/02 Arrangements of lubricant conduits
• CPC Class Codes: F01M 2011/025 for lubricating gudgeon pins
• CPC Class Codes: F16J 1/08 Constructional features providing for lubrication
• CPC Class Codes: F16J 1/16 with gudgeon-pin; Gudgeon-pins

Abstract

A piston has a piston body with a pair of pin bosses having pin bores aligned along a central axis. The pin bores have bearing surfaces, wherein at least one recess extends axially across at least one of the bearing surfaces. A groove extends partially about the bearing surface circumference and is arranged in fluid communication with the recess. The recess and groove provide a lubrication feature to the pin bore, while the bearing surface has an uninterrupted portion for enhanced load carrying capacity.

Claims

1. A piston, comprising:

a piston body having a crown;

a pair of pin bosses having pin bores aligned along a central axis, said pin bores having bearing surfaces;

at least one recess extending axially across at least one of said bearing surfaces; and

a groove in fluid communication with said at least one recess, said groove extending in a circumferential direction about said at least one of said bearing surfaces and terminating at an end within said at least one of said bearing surfaces.

2. The piston of claim 1 wherein said groove has a pair of ends terminating circumferentially away from said recess.

3. The piston of claim 2 wherein said at least one of said bearing surfaces has an uninterrupted portion between said pair of ends of said groove.

4. The piston of claim 3 wherein said uninterrupted portion is between said central axis and said crown.

5. The piston of claim 4 wherein said uninterrupted portion extends between about 60-80 degrees.

7. The piston of claim 1 wherein said at least one bearing surface has an uninterrupted portion extending axially across said at least one of said bearing surfaces, said uninterrupted portion being void of said groove.

8. The piston of claim 1 wherein said groove extends circumferentially in opposite directions from said at least one recess.

9. The piston of claim 1 wherein said crown has an oil gallery, and further comprising an oil port arranged in fluid communication with said oil gallery and said at least one recess.

10. The piston of claim 1 wherein said groove transitions in a gradual taper to said end.

11. The piston of claim 1 wherein said groove has a constant radius.

12. A piston, comprising:

a piston body having a crown;

a pair of pin bosses having pin bores aligned along a central axis, said pin bores having circumferentially extending bearing surfaces;

at least one recess extending axially across at least one of said bearing surfaces; and

a groove in fluid communication with said at least one recess, said groove extending less than 360 degrees about said bearing surface.

13. The piston of claim 12 wherein said groove has at least one end terminating at said bearing surface.

14. The piston of claim 13 wherein said groove has a gradual taper to said end.

15. The piston of claim 13 wherein said groove has a pair of ends terminating at said bearing surfaces.

16. The piston of claim 15 wherein said groove has a gradual taper to said pair of ends.

17. The piston of claim 15 wherein said at least one of said bearing surfaces has an uninterrupted portion extending axially between said pair of ends of said groove.

18. The piston of claim 17 wherein said uninterrupted portion is between said central axis and said crown.

19. The piston of claim 17 wherein said uninterrupted portion extends between about 60-80 degrees.

20. The piston of claim 12 wherein said crown has an oil gallery, and further comprises an oil port arranged in fluid communication with said oil gallery and said at least one recess.

21. The piston of claim 12 wherein said groove has a constant radius.

22. The piston of claim 21 wherein said constant radius has a central axis that is offset from said pin bore central axis.