Cylinder Liner For An Opposed-Piston Engine

Patent metadata

Field	Value
Publication number	US-2016290277-A1
Application number	US-201514675340-A
Country	US
Kind code	A1
Filing date	Mar 31, 2015
Priority date	Mar 31, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

A cylinder liner for an opposed-piston engine, and corresponding methods of extending engine durability and thermal management therewith, has opposite ends and a bore with a longitudinal axis for supporting reciprocating movement of a pair of opposed pistons. An intermediate portion of the liner extends between the opposite ends and includes an annular liner portion within which the pistons reach respective TC locations. A liner ring is seated in a portion of the bore in the annular liner portion, between the TC locations, for scraping carbon from top lands of the pistons and/or increasing the thermal resistance of the annular liner portion.

First claim

1 . A cylinder liner for an opposed-piston engine, comprising:
a cylindrical wall with an interior surface defining a bore centered on a longitudinal axis of the liner, the bore having a first diameter relative to the longitudinal axis; intake and exhaust ports formed in the cylindrical wall near respective opposite ends of the liner; an intermediate portion of the liner extending between the ends and including an annular liner portion containing piston top center (TC) locations; the annular liner portion defined between first and second top ring reversal planes extending orthogonally to the longitudinal axis, in which the first top ring reversal plane is at a first axial position where the topmost ring of a first piston is located when the piston is at its TC location, and the second top ring reversal plane is at a second axial position where the topmost ring of a second piston is located when the piston is at its TC location; and, a liner ring seated in a portion of the bore in the annular liner portion, in which the liner ring has an interior annular surface with a second diameter relative to the longitudinal axis that is less than the first diameter.

2 . The cylinder liner of claim 1 , further including one or more air resistors acting between the liner ring and the bore.

3 . The cylinder liner of claim 1 , further including an annular groove in a portion of the bore contained in the annular liner portion, wherein the liner ring is seated in the annular groove.

4 . The cylinder liner of claim 3 , further including one or more air resistors acting between the liner ring and the bore.

5 . The cylinder liner of claim 1 , wherein the liner ring is formed from a material having a first thermal resistance and the cylinder liner is formed from a material having a second thermal resistance less than the first thermal resistance.

6 . The cylinder liner of claim 5 , further including an annular groove in a portion of the bore contained in the annular liner portion, wherein the liner ring is seated in the annular groove.

7 . The cylinder liner of claim 5 , further including one or more air resistors acting between the liner ring and the bore.

8 . An opposed-piston engine including one or more cylinders, each cylinder comprising a cylinder tunnel in a cylinder block and a cylinder liner according to any one of claims 1 - 7 seated in the cylinder tunnel.

9 . A method for controlling piston carbon in an opposed-piston engine, comprising:
moving a pair of pistons disposed in opposition in the bore of a cylinder liner of the opposed-piston engine; in which the motion of a first piston of the pair of opposed pistons is in an axial direction of the cylinder liner between a first bottom center (BC) position and a first top center (TC) position; in which the motion of a second piston of the pair of opposed pistons is in an axial direction of the cylinder between a second bottom center (BC) position and a second top center (TC) position; wiping carbon from a top land of the first piston as the first piston moves through the first TC position; and, wiping carbon from a top land of the second piston as the second piston moves through the second TC position.

10 . A method for thermal management in a cylinder liner of an opposed-piston engine, comprising:
causing combustion of a mixture of fuel and air between the end surfaces of a pair of pistons disposed in the cylinder liner of the opposed-piston engine when the pistons are near respective top center locations in an annular liner portion of the cylinder liner; and, impeding flow of heat through the cylinder liner with a higher resistance in the annular liner portion than in the rest of the cylinder liner.

11 . A method of manufacturing a cylinder liner for an opposed-piston engine, comprising:
providing a cylinder liner for an opposed-piston engine, in which the cylinder liner includes intake and exhaust ports near respective ends thereof; honing a bore having a first diameter D 1 in the liner; forming an annular groove in the bore at an annular liner portion containing piston top center (TC) locations; providing an annular ring having an interior diameter D 2 , wherein D 1 >D 2 ; heating the cylinder liner to increase the diameter D 1 ; heating the annular ring; placing the annular ring in the bore over the annular groove; swaging the annular ring into the annular groove; and, cooling the cylinder liner and the annular ring.

12 . The method of claim 11 , further including, from either end of the cylinder liner, driving punches with the approximate shape of a piston top land to the annular ring.

13 . The method of claim 12 , further including forming one or more fuel injector ports through the annular liner portion and the annular ring.

14 . The method of claim 13 , further including honing the bore after forming the annular groove.

15 . The method of claim 14 , in which swaging the annular ring into the annular groove includes driving tapered mandrels through the center of the annular ring so as to expand the liner ring into the annular groove.

Assignees

• Achates Power Inc

Inventors

• Koszewnik John J
• Wagner Bryant A

Classifications

• F02F2001/006

  having a ring at the inside of a liner or cylinder for preventing the deposit of carbon oil particles, e.g. oil scrapers · CPC title

• F02F1/004 Primary

  Cylinder liners (F02F1/08, F02F1/16 take precedence) · 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

• F02B75/282

  the pistons having equal strokes · CPC title

• F02F1/186 Primary

  for use in engines with two or more pistons reciprocating within same cylinder · CPC title