Piston assembly for an internal combustion engine of a motor vehicle

Patent metadata

Field	Value
Publication number	US-11313466-B2
Application number	US-201916555573-A
Country	US
Kind code	B2
Filing date	Aug 29, 2019
Priority date	Aug 29, 2019
Publication date	Apr 26, 2022
Grant date	Apr 26, 2022

Abstract

A piston assembly for an internal combustion engine of a motor includes a piston head having an outer diameter surface spaced a first distance from the longitudinal axis and an annular surface spaced a second distance from the longitudinal axis, with the second distance being less than the first distance. Upper and lower walls extend between the annular surface and the outer diameter surface so as to define an annular groove in the outer diameter surface. A piston ring is received within the annular groove and includes an inner diameter surface facing the annular surface of the piston head. The inner diameter surface of the piston ring and the annular surface of the piston head cooperate with one another to define a plurality of pockets angularly spaced from one another about the longitudinal axis and configured to receive oil.

First claim

What is claimed is:

1. A piston assembly for a cylinder of an internal combustion engine of a motor vehicle, the piston assembly comprising:
a piston head adapted to reciprocate along a longitudinal axis within the cylinder, wherein the piston head comprises:
an outer diameter surface spaced a first distance from a longitudinal axis;
an annular surface spaced a second distance from the longitudinal axis with the second distance being less than the first distance; and
upper and lower walls each extending between the annular surface and the outer diameter surface so as to define an annular groove in the outer diameter surface; and

a piston ring received within the annular groove, wherein the piston ring comprises:
a peripheral surface spaced a third distance from the longitudinal axis, with the third distance being longer than the first distance such that the peripheral surface is adapted to slide against a wall of the cylinder in response to the piston head reciprocating along the longitudinal axis;
an inner diameter surface facing the annular surface of the piston head; and
top and bottom side faces each extending between the peripheral surface and the inner diameter surface;

wherein the inner diameter surface of the piston ring and the annular surface of the piston head cooperate with one another to define a plurality of pockets angularly spaced from one another about the longitudinal axis and configured to receive oil;
wherein the piston ring is rotationally fixed in one angular position relative to the piston head;
wherein the top and bottom side faces of the piston ring define a longitudinal wall thickness;
wherein the peripheral surface and the inner diameter surface of the piston ring define a radial wall thickness therebetween; and
wherein the annular surface of the piston head includes a plurality of recesses that forms at least a portion of the pockets.

2. The piston assembly of claim 1 wherein each of the recesses comprises a pair of planar sidewalls extending perpendicularly from the annular surface and a planar end wall extending between the planar sidewalls.

3. The piston assembly of claim 2 wherein the planar end wall is positioned perpendicularly relative to the planar sidewalls.

4. The piston assembly of claim 1 wherein each of the recesses comprises a concave surface of the piston head that extends radially toward the longitudinal axis.

5. The piston assembly of claim 1 wherein the inner diameter surface of the piston ring includes a plurality of recesses that form at least a portion of the pockets.

6. The piston assembly of claim 5 wherein each of the recesses comprises a pair of planar sidewalls extending perpendicularly from the inner diameter surface and a planar end wall extending between the planar sidewalls.

7. The piston assembly of claim 6 wherein the planar end wall is positioned perpendicularly relative to the planar sidewalls.

8. The piston assembly of claim 5 wherein each of the recesses comprises a concave surface that extends radially outwardly relative to the longitudinal axis.

9. The piston assembly of claim 1 wherein the inner diameter surface is spaced a fourth distance from the longitudinal axis, and the fourth distance is longer than the second distance such that the piston ring is angularly movable relative to the piston head.

10. A piston assembly for a cylinder of an internal combustion engine of a motor vehicle, the piston assembly comprising:
a piston head adapted to reciprocate along a longitudinal axis within the cylinder, wherein the piston head comprises:
an outer diameter surface spaced a first distance from a longitudinal axis;
an annular surface spaced a second distance from the longitudinal axis with the second distance being less than the first distance; and
upper and lower walls each extending between the annular surface and the outer diameter surface so as to define an annular groove in the outer diameter surface; and

a piston ring received within the annular groove, wherein the piston ring comprises:
a peripheral surface spaced a third distance from the longitudinal axis, with the third distance being longer than the first distance such that the peripheral surface is adapted to slide against a wall of the cylinder in response to the piston head reciprocating along the longitudinal axis;
an inner diameter surface facing the annular surface of the piston head; and
top and bottom side faces each extending between the peripheral surface and the inner diameter surface;

wherein the inner diameter surface of the piston ring and the annular surface of the piston head cooperate with one another to define a plurality of pockets angularly spaced from one another about the longitudinal axis and configured to receive oil;
wherein the piston ring further comprises an upper chamfered corner positioned between the top side face and the inner diameter surface and a lower chamfered corner positioned between the bottom side face and the inner diameter surface;
wherein the piston ring is rotationally fixed in one angular position relative to the piston head;
wherein the top and bottom side faces of the piston ring define a longitudinal wall thickness;
wherein the peripheral surface and the inner diameter surface of the piston ring define a radial wall thickness therebetween; and
wherein the annular surface of the piston head includes a plurality of recesses that forms at least a portion of the pockets.

11. The piston assembly of claim 10 wherein the inner diameter surface of the piston ring includes a plurality of recesses forming at least a portion of the pockets.

12. The piston assembly of claim 11 wherein each of the recesses comprises a pair of planar sidewalls extending perpendicularly from the inner diameter surface and a planar end wall extending between the planar sidewalls.

13. The piston assembly of claim 12 wherein the planar end wall is positioned perpendicularly relative to the planar sidewalls.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Chinta Balakrishna
• Fisher John B
• Ma Zheng

Classifications

• F16J1/09

  with means for guiding fluids (F16J1/08 takes precedence) · CPC title

• F02B55/08

  Outer members for co-operation with rotary pistons; Casings · CPC title

• F16J9/24

  Members preventing rotation of rings in grooves · CPC title

• F02B55/02 Primary

  Pistons · CPC title

• F16J9/22

  Rings for preventing wear of grooves or like seatings · CPC title