The disclosure describes different types of reciprocating internal combustion engines flexibly mounted in thermally insulating enclosures. A reciprocating component located between two toroidal working volumes in a cylinder is surrounded by an exhaust processing volume, with charge air or gas passing through the interior of the reciprocating component. The enclosures with engines can be “snap-in” mounted into items of equipment needing an engine for operation. In operation, piston extensions or drawbars attached to pistons in operation power crankshafts and/or electrical generators, either rotating or reciprocating. Within an enclosure, air is passed through multiple segregated plenums. Engines having a single piston assembly reciprocating in a cylinder between two combustion chambers are disclosed. Hollow piston assemblies are shown, permitting passage of gas through their interior. Charge air compressors, fuel delivery systems, exhaust emission control systems, electrical generators and exhaust heat energy recovery systems are shown mounted within a single enclosure. Constructional details of pistons transferring power to crankshafts and/or generators via drawbars, as are other construction details.

The disclosure describes different types of reciprocating internal combustion engines flexibly mounted in thermally insulating enclosures. A reciprocating component located between two toroidal working volumes in a cylinder is surrounded by an exhaust processing volume, with charge air or gas passing through the interior of the reciprocating component. The enclosures with engines can be “snap-in” mounted into items of equipment needing an engine for operation. In operation, piston extensions or drawbars attached to pistons in operation power crankshafts and/or electrical generators, either rotating or reciprocating. Within an enclosure, air is passed through multiple segregated plenums. Engines having a single piston assembly reciprocating in a cylinder between two combustion chambers are disclosed. Hollow piston assemblies are shown, permitting passage of gas through their interior. Charge air compressors, fuel delivery systems, exhaust emission control systems, electrical generators and exhaust heat energy recovery systems are shown mounted within a single enclosure. Constructional details of pistons transferring power to crankshafts and/or generators via drawbars, as are other construction details.

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.

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.

A method for controlling operation of an opposed piston engine is provided, comprising: determining a direction of rotation of the engine; comparing the determined direction of rotation to a correct direction of rotation of the engine; and responding to the determined direction of rotation being different from the correct direction of rotation by taking corrective action.

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.

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.

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.

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.

Compact and quiet opposed piston engines (OPEs) are provided. Though compact and quiet, the OPEs provide substantial mechanical shaft power that is required for a range of applications. The inventive OPEs may have a plurality of size displacements.