Abstract: A method of operating a two-stroke cycle, opposed-piston engine comprising a pumping device coupled to pump air to cylinders of the engine through a charge air cooler and an aftertreatment system of thermally-activated devices coupled to receive exhaust from the cylinders by which a thermal state of the exhaust sufficient to sustain thermal activation of one or more of the aftertreatment system devices may be maintained during a deceleration or motoring condition of operation by reducing the mass airflow to the engine.

Abstract: An opposed-piston engine is configured to use hydrogen fuel. The opposed-piston engine has at least one cylinder and a pair of pistons disposed for opposed motion in a bore of the cylinder. Hydrogen fuel is directly side-injected into the cylinder in a compression stroke of the opposed-piston engine, mixed with charge air in the cylinder, and auto-ignited in a combustion chamber formed in the cylinder between the pistons during the compression stroke. A method of operating the hydrogen opposed-piston engine includes switching between a first ignition mode using an externally-generated ignition impulse to ignite the mixture of hydrogen fuel and charge air, and a second ignition mode using compression to ignite the mixture.

Abstract: In an opposed-piston engine which includes a catalytic aftertreatment device in its exhaust system an exhaust gas condition indicating a catalyst temperature of the aftertreatment device is monitored. When the catalyst temperature is near or below a light-off temperature, a catalyst light-off procedure is executed to elevate the temperature of the catalyst.

Abstract: A two-stroke cycle uniflow-scavenged opposed-piston engine is configured to use hydrogen fuel. The opposed-piston engine has at least one cylinder and a pair of pistons disposed for opposed motion in a bore of the cylinder. Hydrogen fuel is injected into the cylinder early in a compression stroke of the opposed-piston engine, and is ignited in a combustion chamber formed between the pistons late in the compression stroke.

Abstract: In an opposed-piston engine which includes a catalytic aftertreatment device in its exhaust system an exhaust gas condition indicating a catalyst temperature of the aftertreatment device is monitored. When the catalyst temperature is near or below a light-off temperature, a catalyst light-off procedure is executed to elevate the temperature of the catalyst.

Abstract: A piston for an internal combustion opposed-piston engine includes a crown part, a skirt part, and an outer part. The crown part includes a first ring belt region for supporting compression rings and an end surface shaped to form a combustion chamber with an end surface of an opposing piston. The skirt part includes a sidewall and a wristpin bore with a first opening and a second opening formed in the sidewall. The outer part includes a second ring belt region for supporting oil control rings. The crown part is joined to an upper end of the sidewall with one or more welding seams. The outer part is joined to a lower end of the sidewall with a welding seam.

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.

Abstract: An opposed-piston engine is configured to use hydrogen fuel. The opposed-piston engine has at least one cylinder and a pair of pistons disposed for opposed motion in a bore of the cylinder. Hydrogen fuel is directly side-injected into the cylinder in a compression stroke of the opposed-piston engine, mixed with charge air in the cylinder, and auto-ignited in a combustion chamber formed in the cylinder between the pistons during the compression stroke. A method of operating the hydrogen opposed-piston engine includes switching between a first ignition mode using an externally-generated ignition impulse to ignite the mixture of hydrogen fuel and charge air, and a second ignition mode using compression to ignite the mixture.

Abstract: A hybrid drive system has two sources of driving power: a non-combustion drive system to provide mechanical torque and rotation to a driveshaft, and an opposed-piston, internal combustion engine configured to provide energy for the non-combustion drive system.

Abstract: A connecting rod assembly has a connecting rod with a large end and a small end, a piston wrist pin, and fasteners to connect the connecting rod to the piston wrist pin and optionally one or more shims in between the connecting rod and piston wrist pin. A notch on the wrist pin allows for the seating of a flat surface on the small end of the connecting rod in the connecting rod assembly. Side walls on both the notch and the small end of the connecting rod limit twist. The connecting rod assembly allows for the adjustment of piston location in a cylinder while limiting connecting rod twist.

Abstract: A cylinder for an internal combustion opposed-piston engine includes a bore, either as part of the cylinder directly or of a liner. The bore has a surface for guiding a pair of pistons disposed for opposing movement in the cylinder. The cylinder bore has three zones of surface finishes: an inner zone extending between and including exhaust and intake ports, where only piston compression rings travel on the bore surface; two instances of an outer zone where only piston oil control rings travel on the bore surface; and two instances of a port zone where both types of rings travel on overlapping paths in the same bore surface portion. Each zone may have a particular surface finish that is tailored to specific requirements including oil control, ring wear, and scuff resistance relevant to the zone.

Abstract: A hybrid drive system has two sources of driving power: a non-combustion drive system to provide mechanical torque and rotation to a driveshaft, and an opposed-piston, internal combustion engine configured to provide energy for the non-combustion drive system.

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.

Abstract: A two-stroke cycle uniflow-scavenged opposed-piston engine is configured to use hydrogen fuel. The opposed-piston engine has at least one cylinder and a pair of pistons disposed for opposed motion in a bore of the cylinder. Hydrogen fuel is injected into the cylinder early in a compression stroke of the opposed-piston engine, and is ignited in a combustion chamber formed between the pistons late in the compression stroke.

Abstract: The present disclosure provides piston, comprising: a skirt having an upper body portion; a crown formed at the upper body portion; and a piston bowl formed at the crown. The piston bowl includes a first combustion surface and a second combustion surface opposite the first combustion surface. Each of the first combustion surface and the second combustion surface are formed and positioned to accommodate inflowing injector spray so as to reduce heat transfer caused by impingements made by the inflowing injector spray.

Abstract: A method of operating a two-stroke cycle, opposed-piston engine comprising a pumping device coupled to pump air to cylinders of the engine through a charge air cooler and an aftertreatment system of thermally-activated devices coupled to receive exhaust from the cylinders by which a thermal state of the exhaust sufficient to sustain thermal activation of one or more of the aftertreatment system devices may be maintained during a deceleration or motoring condition of operation by reducing the mass airflow to the engine.

Abstract: A cylinder having at least one intake port and at least one exhaust port, wherein the at least one intake port includes an upper surface and a lower surface, the upper surface of the intake port having an entrance portion and an outlet portion, the upper surface arced from the entrance portion to the outlet portion.

Abstract: The present disclosure provides a piston for an internal combustion engine, the piston having a piston body including a first bearing saddle defining a first axis and a second bearing saddle defining a second axis, the first axis being parallel to and spaced from the second axis. A bearing is also provided, the bearing having a first journal having a first body, longitudinal ends, and lateral edges, the first journal defining a first axis, the first journal disposed about approximately 180 degrees of the first axis and a second journal having a second body and defining a second axis, the second journal disposed about approximately 180 degrees of the second axis, the second journal operable to be positioned abutting one of the lateral edges of the first journal when the first and second journals are positioned with the piston.

Abstract: An air handling arrangement in a two-stroke cycle, opposed-piston engine with uniflow scavenging and constructed for heavy-duty operation includes sequentially arranged turbochargers in series with a supercharger. In some aspects, the air handling system is equipped with an EGR channel.

Abstract: An opposed-piston engine includes an electronic sensor located in a charge air channel, at position between an outlet of a charge air cooler and an air intake component that distributes charge air to cylinder intake ports of the engine. The electronic sensor is disposed to measure a rate of mass airflow between the outlet of the charge air cooler and the intake component and generate electronic signals indicative of the rate of mass airflow from the charge air cooler. A control mechanization of the opposed-piston engine is electrically connected to the electronic sensor for controlling air handling devices, fuel provisioning devices, and/or EGR devices in response to the electronic signals.