Weight balanced internal combustion engine piston

Patent metadata

Field	Value
Publication number	US-9097202-B2
Application number	US-91672710-A
Country	US
Kind code	B2
Filing date	Nov 1, 2010
Priority date	Oct 30, 2009
Publication date	Aug 4, 2015
Grant date	Aug 4, 2015

Abstract

A piston for an internal combustion engine includes a piston crown connected to and above a body portion of the piston. The body portion forms two pin bores and the piston crown defines an outer cylindrical wall. At least one piston ring seal groove is formed in the outer cylindrical wall and extends peripherally around the piston crown. A first oil collection groove is formed in the outer cylindrical wall below the piston ring seal groove. The first oil collection groove has a first width measured along a centerline of the piston. A second oil collection groove is formed in the outer cylindrical wall below the first oil collection groove, extends parallel to the first oil collection groove around the entire periphery of the piston, and has a width that is at least double the width of the first oil collection groove.

First claim

We claim:

1. A piston for an internal combustion engine, comprising:
a piston crown connected to and above a body portion of the piston, the body portion forming two pin bores, and the piston crown defining an outer cylindrical wall;
at least one piston ring seal groove formed in the outer cylindrical wall and extending peripherally around the piston crown, the at least one piston ring seal groove being configured to accommodate therein a piston ring seal;
a first oil drainage groove formed in the outer cylindrical wall below the at least one piston ring seal groove and extending in parallel to the at least one piston ring seal groove around an entire periphery of the piston, wherein the first oil drainage groove has a first width measured along a centerline of the piston;
a plurality of drain openings formed in the body portion, the plurality of drain openings fluidly connecting the first oil drainage groove with an internal gallery of the piston;
a second oil drainage groove formed in the outer cylindrical wall below and adjacent the first oil drainage groove, the second oil drainage groove defining a first channel, a second channel, and an annular protrusion disposed between the first channel and the second channel, the annular protrusion defining a reduced-diameter land portion;
wherein the second oil drainage groove extends parallel to the first oil drainage groove around the entire periphery of the piston but is interrupted over segments of the body portion that accommodate the two pin bores such that oil collected in the second oil drainage groove drains from the first channel to the second channel, and from the second channel back to the internal combustion engine through the segments and externally to the piston,
wherein the second oil drainage groove has a width that is wider than the width of the first oil drainage groove; and
at least one additional piston ring groove being sized to receive a piston ring seal therein, the at least one additional piston ring groove disposed adjacent the at least one piston ring seal groove.

2. The piston of claim 1 , wherein the outer cylindrical wall has a first diameter, and wherein a reduced diameter land is defined by an annular portion of the piston that is disposed within the second oil drainage groove, wherein the reduced diameter land has an outer diameter that is less than the first diameter of the outer cylindrical wall.

3. The piston of claim 2 , wherein the annular portion partitions the second oil drainage groove into a first channel that is disposed above the annular portion, and a second channel that is disposed below the annular portion.

4. The piston as set forth in claim 1 , further comprising a barrier wall disposed adjacent the at least one piston ring groove and between said at least one piston ring and a recessed portion disposed below said at least one piston ring groove, the barrier wall configured to retain the piston ring disposed therein.

5. The piston according to claim 4 , wherein said recessed portion is disposed in said weight balance section and comprises an annular groove defined by a nominal depth of 5.34 mm, the at least one piston ring seal groove is defined by a nominal width of 4 mm, and the barrier wall is defined by a nominal width of 4 mm.

6. The piston of claim 1 , wherein the second oil drainage groove has a width that is at least twice as large as a width of the first oil drainage groove.

7. The piston of claim 1 , wherein a nominal outer diameter of the piston is 136 mm, and wherein said recessed portions of said weight balance section is an annular groove defined by a nominal depth of 5.34 mm and a nominal width of 9 mm.

8. An internal combustion engine having a cylinder bore configured to reciprocally accept a piston, comprising:
a piston having a piston crown and a body portion, the piston crown defining an outer cylindrical wall and being connected to and above the body portion, the body portion forming two pin bores configured to pivotally connect the piston to a connecting rod of the engine;
at least one piston ring seal groove formed in the outer cylindrical wall and extending peripherally around the piston crown, the at least one piston ring seal groove being configured to accommodate therein a piston ring seal;
an additional piston ring groove configured to receive an additional piston ring therein, the additional piston ring groove disposed adjacent the at least one piston ring seal groove;
a first oil drainage groove formed in the outer cylindrical wall below and adjacent to the additional piston ring seal groove, the first oil drainage groove extending in parallel to the at least one piston ring seal groove around an entire periphery of the piston, wherein the first oil drainage groove has a first width measured along a centerline of the piston;
a plurality of drain openings formed in the body portion, the plurality of drain openings fluidly connecting the first oil drainage groove with an internal gallery of the piston; and
a second oil drainage groove formed in the outer cylindrical wall below and adjacent the first oil drainage groove, the second oil drainage groove defining a first channel, a second channel, and an annular protrusion disposed between the first channel and the second channel, the annular protrusion defining a reduced-diameter land portion;
wherein the second oil drainage groove extends parallel to the first oil drainage groove around the entire periphery of the piston but is interrupted over segments of the body portion that accommodate the two pin bores such that oil collected in the second oil drainage groove drains from the first channel to the second channel, and from the second channel back to the internal combustion engine through the segments and externally to the piston is provided,
wherein the second oil drainage groove has a width that is wider than the width of the first oil drainage groove.

9. The internal combustion engine of claim 8 , further comprising a reduced diameter land is defined by an annular portion of the piston that is disposed within the second oil drainage groove, wherein the outer cylindrical wall has a first outer diameter, and wherein the reduced diameter land has a second outer diameter that is less than the first outer diameter.

10. The internal combustion engine of claim 9 , wherein the annular portion partitions the second oil drainage groove into a first channel that is disposed above the annular portion, and a second channel that is disposed below the annular portion.

11. The internal combustion engine of claim 8 , wherein a nominal outer diameter of the piston is 136 mm, and wherein said recessed portions of said weight balance section is an annular groove defined by a nominal depth of 5.34 mm and a nominal width of 9 mm.

12. The internal combustion engine of claim 8 , wherein said recessed portion is disposed in said weight balance section and comprises an annular groove defined by a nominal depth of 5.34 mm, the at least one piston ring seal groove is defined by a nominal width of 4 mm, and the barrier wall is defined by a nominal width of 4 mm.

13. A piston for an internal combustion engine, comprising:
a piston crown connected to and above a body portion of the piston, the body portion forming two pin bores, and the piston crown defining an outer cylindrical wall;
at least one piston ring seal groove formed in the outer cylindrical wall and extending peripherally around the piston crown, said at least one piston ring seal groove has tapered walls forming a generally V-shaped cross section;
a first oil drainage groove formed in the outer cylindrical wall below the at least one piston ring se

Assignees

• He Jie
• Buening Jeffrey Paul
• Caterpillar Inc

Inventors

• He Jie
• Buening Jeffrey Paul

Classifications

• F02F3/22

  the fluid being liquid · CPC title

• F02F3/003 Primary

  the parts being connected by casting, brazing, welding or clamping · CPC title

• F02F2200/04

  Forging of engine parts · CPC title

• Y10T29/49249

  Piston making · CPC title

• F02F2003/0061

  by welding · CPC title