Piston for an opposed-piston engine

Patent metadata

Field	Value
Publication number	US-11773769-B2
Application number	US-202217873473-A
Country	US
Kind code	B2
Filing date	Jul 26, 2022
Priority date	Jul 30, 2021
Publication date	Oct 3, 2023
Grant date	Oct 3, 2023

Abstract

In an opposed-piston engine, a piston has a top land. The piston top land has a non-cylindrical shape which affords more clearance with a piston bore to thrust and anti-thrust sides than to front-facing and rear facing sides.

First claim

The invention claimed is:

1. A combination for an opposed-piston engine, comprising:
at least one cylinder;
a pair of pistons with end surfaces, which are disposed for reciprocating movement in a bore of the cylinder with their end surfaces facing;
each of the pistons comprising:
a tubular body with a wristpin boss arrangement;
the tubular body capped by a crown having an end surface configured to form a combustion chamber with an end surface of the other piston;
the crown having a top land with two first sides, respectively facing in a thrust direction and an anti-thrust direction, and two second sides, respectively facing in an engine-rear direction and facing in an engine-front direction;
in which thrust and anti-thrust directions are orthogonal to the engine-front direction and the engine-rear direction; and,
in which the two first sides are configured to have a greater clearance with the bore than the two second sides.

2. The combination of claim 1 , the crown comprising a ring belt region, wherein the top land is between the ring belt region and the end surface.

3. The combination of claim 2 , the ring belt region comprising at least one ring groove, wherein the top land is between a top edge of the at least one ring groove and the end surface.

4. The combination of claim 1 , the crown comprising a side surface including an annular ring belt region in which a plurality of ring grooves is formed, in which:
a top ring groove of the annular ring belt region is closest to the end surface;
the top land comprises a portion of the side surface between the top ring groove and the end surface; and
the top land meets the end surface at an edge which defines a periphery of the end surface.

5. The combination of claim 4 , wherein the annular belt region is a top belt region of the piston, the piston further comprising a bottom belt region.

6. The combination of claim 5 , further comprising at least one injector trench opening through the peripheral edge and having a shape for guiding fuel injected into a bowl formed in the end surface.

7. The combination of claim 1 , in which the two second sides have a circular profile with a diameter D 1 , the two first sides have a circular profile with a diameter D 2 , and the diameter D 1 is greater than the diameter D 2 .

8. The combination of claim 7 , in which the diameter D 2 increases clearance to the cylinder bore along the thrust and anti-thrust sides compared to the clearance to the bore along the engine rear and engine front sides.

Assignees

• Achates Power Inc

Inventors

• Chown Daniel M
• Mackenzie Ryan G
• Thomas Isaac B

Classifications

• F02B75/282 Primary

  the pistons having equal strokes · CPC title

• F01B7/02

  with oppositely reciprocating pistons · CPC title

• F02F3/00

  Pistons · CPC title

• F02F3/24

  having means for guiding gases in cylinders, e.g. for guiding scavenging charge in two-stroke engines · CPC title

• F02B2075/025

  two · CPC title