An internal combustion may include a cylinder having a first combustion chamber at one end and a second combustion chamber at an opposing end, first and second cylinder heads located at an end of the first and second combustion chambers, respectively, and a double-faced piston slidably mounted therein. The piston may be configured to move in a first stroke that includes an expansion stroke portion and a non-expansion stroke portion. The engine may further include first and second piston rod portions extending from opposite faces of the piston. A recess in the piston rod portions may be configured to communicate gases between a combustion chamber and locations outside the cylinder. There may also be a chamber surrounding the first or second piston rod portion, the chamber configured to be supplied with gas and the chamber being isolated from the first combustion chamber and the second combustion chamber.

High pressure pump systems with reduced pressure ripple for use with waterjet systems and other systems are described herein. A pump system configured in accordance with a particular embodiment includes four reciprocating members operably coupled to a crankshaft at 90 degree phase angles. The reciprocating members can include plungers operably disposed in corresponding cylinders and configured to compress fluid (e.g., water) in the cylinders to pressures suitable for waterjet processing, such as pressures exceeding 30,000 psi.

Filter assemblies and components therefor, are described. In an example arrangement, the crankcase ventilation filter assembly is configured to be serviced from either the top or the bottom. A rotational indexing arrangement is to ensure appropriate orientation of an internally received filter cartridge, and other components of the arrangement are provided. Methods of assembly, servicing and use are described.

Filter assemblies and components therefor, are described. In an example arrangement, the crankcase ventilation filter assembly is configured to be serviced from either the top or the bottom. A rotational indexing arrangement is to ensure appropriate orientation of an internally received filter cartridge, and other components of the arrangement are provided. Methods of assembly, servicing and use are described.

A combined heat and power microgrid system is provided that stores energy in the form of compressed air that can then be utilized as needed in the form of electricity. The compressed air may be generated with energy from multiple electrical energy sources, such as renewable energy sources. The energy stored as compressed air/heat is used to charge a battery by utilizing a pulley system and a barrel housing that transfers kinetic energy generated by the release of the compressed air to an array of piezoelectric generators that can produce electricity, which is stored in the second battery. In addition, water may be extracted from the compressed air storage tank. In this way, energy produced by the renewable sources can be accessed during periods of high need or low production and water may be collected.

A combined heat and power microgrid system is provided that stores energy in the form of compressed air that can then be utilized as needed in the form of electricity. The compressed air may be generated with energy from multiple electrical energy sources, such as renewable energy sources. The energy stored as compressed air/heat is used to charge a battery by utilizing a pulley system and a barrel housing that transfers kinetic energy generated by the release of the compressed air to an array of piezoelectric generators that can produce electricity, which is stored in the second battery. In addition, water may be extracted from the compressed air storage tank. In this way, energy produced by the renewable sources can be accessed during periods of high need or low production and water may be collected.

A high efficiency variable cutoff uniflow steam engine with piston operated valves has an exhaust valve that is held open by a spring during the exhaust stroke but is closed at an end of the exhaust stroke by the piston compressing steam in a compartment associated to act on the exhaust valve. The piston continues to move in the same direction a short distance toward top dead center (TDC) compressing a small residual quantity of steam in the cylinder above the piston during the remaining fraction of the exhaust stroke with sufficient pressure to open the steam inlet valve by steam pressure without an impact caused by physical contact with the piston.

A combined heat and power microgrid system is provided that stores energy in the form of compressed air that can then be utilized as needed in the form, of electricity. The compressed air may be generated with energy from multiple electrical energy sources, such as renewable energy sources. The energy stored as compressed air/heat is used to charge a battery by utilizing a pulley system and a barrel housing that transfers kinetic energy generated by the release of the compressed air to an array of piezoelectric generators that can produce electricity, which is stored in the second battery. In addition, water may be extracted from the compressed air storage tank. In this way, energy produced by the renewable sources can be accessed during periods of high need or low production and water may be collected.

A combined heat and power microgrid system is provided that stores energy in the form of compressed air that can then be utilized as needed in the form, of electricity. The compressed air may be generated with energy from multiple electrical energy sources, such as renewable energy sources. The energy stored as compressed air/heat is used to charge a battery by utilizing a pulley system and a barrel housing that transfers kinetic energy generated by the release of the compressed air to an array of piezoelectric generators that can produce electricity, which is stored in the second battery. In addition, water may be extracted from the compressed air storage tank. In this way, energy produced by the renewable sources can be accessed during periods of high need or low production and water may be collected.

A reciprocating compressor is provided. Bearing holes of a fluid bearing of the compressor may be positioned to correspond to a full reciprocating region of a piston, to reduce/eliminate frictional loss and/or abrasion between a cylinder and the piston. The bearing holes may be concentrated at certain regions of the cylinder to stably support the piston through a full reciprocating range. Compression coil springs may maintain concentric alignment of the cylinder and the piston. Gas through holes may be radially formed at the piston to lower a pressure of a bearing space and allow refrigerant to be smoothly introduced into the bearing space through a gas pocket A casing of the compressor may include an outer shell and an inner shell to attenuate vibration generated due to friction generated by operation of the reciprocating compressor.