Intake system for an opposed-piston engine
AssigneeEcoMotors, Inc.
InventorsRobert Levy, Amr Gamal Sami
Life of this patent
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Abstract
An opposed-piston engine has a plurality of intake ports wrapped around the cylinder wall. It is desirable to obtain high swirl ratio flow with minimal pressure drop. A system have a generally-volute shaped plenum is disclosed. A centerline of the volute spirals inwardly. Furthermore, the cross-sectional area of the volute decreases in the direction of flow. The area is decreased as the flow from the plenum enters intake ports so that the velocity of flow in the plenum near the downstream end does not slow precipitously. The intake system may have multiple such volute-shaped plena coupled to mutually exclusive subsets of the intake ports. The volute shape leads to a high swirl ratio with limited drop in flow energy.
Claims19
An internal-combustion engine system, comprising:
- a cylinder wall having a plurality of intake ports defined therein at a first distance along the cylinder wall and a plurality of exhaust ports defined therein at a second distance along the cylinder wall;
- a crankshaft;
- an intake piston disposed within the cylinder wall and coupled to the crankshaft via a connecting rod with the piston adapted to reciprocate in the cylinder in response to rotation of the crankshaft thereby covering and uncovering the intake ports;
- an intake system coupled to the intake ports with the intake system including:
- a first generally volute-shaped plenum fluidly coupled to a first portion of the intake ports and a locus of geometric centers of cross sections of the first plenum spirals inwardly with a monotonically decreasing radius as considered in the direction of flow;
- and
- a second generally volute-shaped plenum fluidly coupled to a second portion of the intake ports and a locus of geometric centers of cross sections of the second plenum spiral inwardly with a generally decreasing radius as considered in the direction of flow, wherein:
- the first and second plena wrap around an outside of the cylinder wall with a direction of flow induced in the first and second plena having the same rotational direction.
The engine system of 1 wherein the first plenum and the second plenum are fluidly decoupled upstream of the intake ports.
An intake system for a two-stroke, internal-combustion engine, comprising:
- a cylinder having a first set and a second set of intake ports defined therein;
- a first volute-shaped plenum fluidly coupled to the first set of intake ports on an upstream side of the intake ports;
- a second volute-shaped plenum fluidly coupled to the second set of intake ports on an upstream side of the intake ports wherein cross-sectional area of first and second volutes generally decreases in a direction of flow;
- the first and second plena are fluidly decoupled upstream of the intake ports;
- and a direction of flow induced in the first plenum is in the same rotational direction as a direction of flow induced in the second plenum,
- the engine further comprising:
- a first intake runner fluidly coupled to the first plenum;
- and
- a second intake runner fluidly coupled to the second plenum.
An internal-combustion engine system, comprising:
- a cylinder wall having a first set and a second set of intake ports and a plurality of exhaust ports defined therein;
- a crankshaft;
- an intake piston disposed within the cylinder wall and coupled to the crankshaft via a connecting rod with the piston adapted to reciprocate in the cylinder in response to rotation of the crankshaft thereby covering and uncovering the intake ports;
- a first volute-shaped plenum fluidly coupled to the first set of intake ports on an upstream side of the intake ports with a cross-sectional area of the first plenum decreasing monotonically in a direction of flow;
- and
- a second volute-shaped plenum fluidly coupled to the second set of intake ports on an upstream side of the intake ports with a cross-sectional area of the second plenum generally decreasing in a direction of the flow for a portion of the second plenum wherein the first and second plena are fluidly decoupled upstream of the intake ports wherein cross section of the plenum are taken through a central axis of the cylinder wall;
- the first plenum directs flow in a first rotational direction;
- the second plenum directs flow in a second rotational direction;
- and the first and second rotational directions are the same.
Dependencies are inferred from the claim text.