Back to results
US 8,763,583 B2Granted
Opposed-piston, opposed-cylinder engine with collinear cylinders
AssigneeEcoMotors, Inc.
InventorsPeter Hofbauer, Adrian Tusinean
Life of this patent
Estimating the term…
Abstract
An opposed-piston, opposed-cylinder OPOC engine is disclosed in which the central axis of the two cylinders is collinear. In four-stroke engines, this is possible with a built up crankshaft. Disclosed are connecting rod configurations that are suitable for a two-stroke engine that can be assembled to a unitary crankshaft, including both pullrods in tension and pushrods in compression. The configuration includes pistons arranged symmetrically, but with offset timing of the intake and exhaust pistons. The offset timing leads to a slight imbalance which can be partially overcome by having the center of gravity of the crankshaft offset from the axis of rotation.
Claims18
An opposed-piston, opposed-cylinder engine, comprising:
- a first cylinder having a first inner piston and a first outer piston disposed therein;
- a second cylinder having a second inner piston and a second outer piston disposed therein, the second cylinder having a central axis substantially collinear with a central axis of the first cylinder;
- a unitary crankshaft disposed between the first and second cylinders, the crankshaft having a first main bearing, a first outer eccentric journal, a center eccentric journal, a second outer eccentric journal and a second main bearing;
- a first pushrod coupling the first inner piston with the center eccentric journal;
- a second pushrod coupling the second inner piston with the center eccentric journal wherein both the first and second pushrods lie in a plane perpendicular to a centerline of the center eccentric journal and such plane intersects the center eccentric journal;
- a first pullrod with a first end of the first pullrod coupled to the first outer piston and a second end of the first pullrod wrapped around a portion of the first outer eccentric journal;
- a second pullrod with a first end of the second pullrod coupled to the first outer piston and a second end of the second pullrod wrapped around a portion of the second outer eccentric journal;
- a third pullrod with a first end of the third pullrod coupled to the second outer piston and a second end of the third pullrod wrapped around a portion of the first outer eccentric journal;
- and
- a fourth pullrod with a first end of the fourth pullrod coupled to the second outer piston and a second end of the fourth pullrod wrapped around a portion of the second outer eccentric journal.
7 more elements
An opposed-piston, opposed-cylinder engine, comprising:
- a first cylinder having a first intake piston and a first exhaust piston disposed therein;
- a second cylinder having a second intake piston and a second exhaust piston disposed therein, the second cylinder having a central axis substantially collinear with a central axis of the first cylinder;
- a crankshaft comprised of a single piece disposed between the first and second cylinders, the crankshaft having a first outer main bearing, a first outer eccentric journal, a center eccentric journal, a second outer eccentric journal and a second outer main bearing;
- a first pushrod coupling the first exhaust piston with the center eccentric journal;
- a second pushrod coupling the second exhaust piston with the center eccentric journal;
- a first pullrod with a first end of the first pullrod coupled to the first intake piston and a second end of the first pullrod coupled to the first outer eccentric journal via a first bearing cap;
- a second pullrod with a first end of the second pullrod coupled to the first intake piston and a second end of the second pullrod coupled to the second outer eccentric journal via a second bearing cap;
- a third pullrod with a first end of the third pullrod coupled to the second intake piston and a second end of the third pullrod coupled to the first outer eccentric journal via a third bearing cap;
- and
- a fourth pullrod with a first end of the fourth pullrod coupled to the second intake piston and a second end of the fourth pullrod coupled to the second outer eccentric journal via a fourth bearing cap wherein the eccentric journals are arranged on the crankshaft such that the exhaust pistons reach their extreme in travel before the intake pistons with a phase angle difference in the range of 5 to 25 crank angle degrees;
- and a center of gravity of the crankshaft is displaced from the axis of rotation of the crankshaft to counteract roughly half of an unbalanced inertia force that is generated by the phase angle difference between the intake and exhaust pistons.
8 more elements
A method to couple pistons to a crankshaft of an opposed-piston, opposed-cylinder engine, the method comprising:
- placing a first pushrod over a center eccentric journal of the crankshaft;
- placing a second pushrod over a center eccentric journal of the crankshaft;
- placing a first retainer over the center eccentric journal opposite the first pushrod;
- engaging the first retainer with a shoulder on the second pushrod;
- placing a second retainer over the center eccentric journal opposite the second pushrod;
- and
- engaging the second retainer with a shoulder on the first pushrod wherein the first pushrod is coupled to a first inner piston on an end of the first pushrod distal from the crankshaft and the second pushrod is coupled to a second inner piston an end of the second pushrod.
4 more elements
Dependencies are inferred from the claim text.