Piston Cooling For Opposed-Piston Engines

Patent metadata

Field	Value
Publication number	US-2016201544-A1
Application number	US-201514596855-A
Country	US
Kind code	A1
Filing date	Jan 14, 2015
Priority date	Jan 14, 2015
Publication date	Jul 14, 2016
Grant date	—

Abstract

Pistons for opposed-piston engines include an interior annular cooling gallery. The gallery is provided with inlet and drain passageways constructed to shield a jet of liquid coolant entering the gallery, thereby reducing interference between the incoming jet and liquid coolant circulating in the gallery.

First claim

1 . A piston for an opposed-piston engine, comprising:
a crown with an end surface shaped to define a combustion chamber with an end surface of an opposing piston in the opposed-piston engine; a skirt part including a piston sidewall extending from the crown to an open end of the skirt part; an annular cooling gallery within the piston; at least one coolant inlet passageway within the piston including an outlet opening in the annular cooling gallery; and, at least one coolant drain passageway within the piston, separate from the coolant jet passageway, and including a drain opening in the annular coolant gallery; the outlet opening being nearer an under surface of the crown than the drain opening.

2 . The piston of claim 1 , in which the coolant inlet and drain passageways extend through an interior wall of the skirt part.

3 . The piston of claim 2 , in which the annular gallery is defined between a peripheral portion of a first side of the interior wall and a peripheral portion of the under surface.

4 . The piston of claim 3 , in which a second side of the interior wall opposite the first side includes at least a portion of a wristpin bore.

5 . The piston of claim 3 , in which the inlet passageway has the shape of an elongated circle in cross section and the drain passageway has the shape of a circle in cross section.

6 . The piston of claim 1 , in which the outlet opening is positioned in alignment with a convex portion of the under surface.

7 . The piston of claim 1 , in which the at least one coolant drain passageway includes two coolant drain passageways with respective drain openings that flank the inlet passageway on either side.

8 . The piston of claim 1 , in which the coolant outlet opening is positioned in a reference plane that divides the cooling gallery into first and second portions and is orthogonal to the longitudinal axis, and the drain opening is positioned at a distance D from the reference plane in the direction of the open end.

9 . A piston for an opposed-piston engine, the piston having a longitudinal axis and comprising:
a crown with an end surface shaped to define a combustion chamber with an end surface of an opposing piston in the opposed-piston engine; a skirt part joined to the crown; the crown including first ring grooves; the skirt part including second ring grooves spaced apart from the first ring grooves along the longitudinal axis; the skirt part including a piston sidewall with opposing skirt portions extending from the first to the second ring grooves and separated from one another by intervening sidewall indentations running along the longitudinal axis between the first and second ring grooves; an annular cooling gallery within the piston; first and second opposing coolant inlet passageways, each including an outlet opening into the annular cooling gallery; and, coolant drain passageways flanking respective sides of each inlet passageway, each coolant drain passageway including a drain opening in the annular cooling gallery; wherein each outlet opening is positioned a first distance from an under surface of the crown, each drain opening is positioned a second distance from the under surface of the crown, and the second distance is greater than the first distance.

10 . The piston of claim 9 , in which the coolant inlet and drain passageways extend through an interior wall of the skirt part.

11 . The piston of claim 10 , in which the annular gallery is defined between a peripheral portion of a first side of the interior wall and a peripheral portion of the under surface.

12 . The piston of claim 11 , in which a second side of the interior wall opposite the first side includes at least a portion of a wristpin bore.

13 . The piston of claim 11 , in which the inlet passageway has the shape of an elongated circle in cross section and the drain passageway has the shape of a circle in cross section.

14 . The piston of claim 9 , in which each inlet passageway extends through the interior wall and includes a chimney in the cooling gallery that extends in the direction of the crown under surface.

15 . The piston of claim 14 , in which each drain passageway is positioned in a respective bowl in the interior wall.

16 . The piston crown of claim 9 , in which each coolant inlet passageway is adjacent to a respective sidewall portion.

17 . A method of cooling a piston that has a crown with an end surface shaped to define a combustion chamber with an end surface of an opposing piston in the opposed-piston engine, a skirt part joined to the crown, and an annular cooling gallery within the piston defined between the crown and the skirt part, comprising:
providing at least one jet of liquid coolant aimed at an under surface of the crown from a first level in the annular cooling gallery; and, draining the liquid coolant from a second level in the annular gallery that is further from the undersurface than the first level.

18 . The method of claim 17 , in which draining the liquid coolant from the second level includes draining the liquid coolant at respective sides of the jet.

19 . The method of claim 18 , in which providing at least one jet of liquid coolant includes providing respective jets of liquid coolant in opposite sides of the annular gallery.

20 . A method of cooling a piston that has a crown with an end surface shaped to define a combustion chamber with an end surface of an opposing piston in the opposed-piston engine, a skirt part joined to the crown, and an annular cooling gallery within the piston defined between the crown and the skirt part, comprising:
providing at least one jet of liquid coolant aimed at an under surface of the crown from an outlet in the annular cooling gallery; and, shielding the jet of liquid coolant from liquid coolant circulating in the annular gallery.

Assignees

• Achates Power Inc

Inventors

• Mackenzie Ryan G
• Redon Fabien G

Classifications

• F01P3/10 Primary

  Cooling by flow of coolant through pistons · CPC title

• F02B23/06 Primary

  the combustion space being arranged in working piston (F02B23/04 takes precedence) · CPC title

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F01P11/02

  Liquid-coolant {filling}, overflow, venting, or draining devices (automatic draining during freezing conditions F01P11/20) · CPC title

• F02B75/28

  Engines with two or more pistons reciprocating within same cylinder or within essentially coaxial cylinders (arranged oppositely relative to main shaft F02B75/24) · CPC title