An internal combustion engine is provided with a pre-chamber provided inside a main combustion chamber. The pre-chamber includes an ignition plug, and a casing provided to a ceiling part to cover the ignition plug, the casing isolating an internal space formed therein from the main combustion chamber. A tumble flow of a mixture gas is formed inside the main combustion chamber. A plurality of communicating holes are formed in the casing, and include a first communicating hole opening to an intake port side and a second communicating hole opening to an exhaust port side. The tumble flow flowing into the pre-chamber through the first communicating hole forms in the pre-chamber a vortex flowing in the opposite direction from the tumble flow. The main combustion chamber is provided with a structure configured to suppress a flow opposing the vortex flowing into the pre-chamber through the second communicating hole.

A passive prechamber spark plug for use in a combustion chamber of a vehicle engine includes an upper prechamber having an upper opening where the upper prechamber is connectable to the combustion chamber via the upper opening. An air ignition spark is formable via an upper air spark gap. A central electrode is disposed in an upper region of the upper prechamber where a base of the upper prechamber opposite the upper region is an insulator. An electrically conductive element or a slot is guided by the insulator continuously from the upper prechamber into a lower region under the base and the lower region is either a lower prechamber or is arrangeable directly in the combustion chamber. An earth electrode is disposed in the lower region such that a lower air spark gap is formed between the earth electrode and the electrically conductive element or the slot.

A passive prechamber spark plug for use in a combustion chamber of a vehicle engine includes an upper prechamber having an upper opening where the upper prechamber is connectable to the combustion chamber via the upper opening. An air ignition spark is formable via an upper air spark gap. A central electrode is disposed in an upper region of the upper prechamber where a base of the upper prechamber opposite the upper region is an insulator. An electrically conductive element or a slot is guided by the insulator continuously from the upper prechamber into a lower region under the base and the lower region is either a lower prechamber or is arrangeable directly in the combustion chamber. An earth electrode is disposed in the lower region such that a lower air-surface gap spark gap is formed between the earth electrode and the electrically conductive element or the slot.

Embodiments of the present invention provide a pre-combustion chamber assembly, comprising (a) a body, having a cylindrical end portion having a step-wise increase in diameter forming a sealing surface for sealing to an engine; (b) a tip, with a hollow shaft in fluid communication with a combustion region of the tip, where the shaft has a first shaft diameter that allows the shaft to be slid over a portion of the body; (c) a gasket mounted about the body and resting against the sealing surface, wherein the gasket comprises a wire wound washer.

Flowpath assemblies, methods of forming flowpath assemblies, and hypersonic vehicles are provided. For example, a flowpath assembly for a combustor comprises a tube array comprising a plurality of tubes, a joining material disposed between adjacent tubes of the plurality of tubes to join together the adjacent tubes, a flowpath layer, and an outer layer. The plurality of tubes and the joining material are disposed between the flowpath layer and the outer layer. The flowpath layer defines a combustion flowpath. Each of the plurality of tubes, the joining material, the flowpath layer, and the outer layer are formed from a composite material. The combustor comprising the flowpath assembly may be included in a ramjet engine of a hypersonic vehicle. A fabrication method may include laying up composite plies to form a tube array including the plurality of tubes, the joining material, and the flowpath and outer layers.

An active prechamber device may include a prechamber housing longitudinally aligned with a main axis. The active prechamber device may also include a prechamber nozzle forming a cap at an end of the prechamber housing. The prechamber nozzle and prechamber housing may define a prechamber space that extends along the main axis. The prechamber nozzle may have a plurality of orifices fluidly connected to the prechamber space. Additionally, a fuel injector may be in a linear arrangement with the prechamber housing along the main axis. The fuel injector may have a fuel injection nozzle positioned to spray a fuel into the prechamber space. An electrode arrangement may be formed within the prechamber space. The electrode arrangement may include an electrode shaft and an electrode ring. The electrode ring may circumscribe the electrode shaft to form a spark gap within the prechamber space.

Air compressor comprising a centrifugal-type compression wheel defining an axial direction and a radial direction, an air intake opening extending circumferentially around the compression wheel and opening onto a compression part, the compression part comprising a first portion forming a volute for the ejection of compressed air which is mounted facing the compression wheel in the radial direction, and an at least partly annular second portion extending around the first portion, the second portion comprising a central orifice receiving at least part of the compression wheel and an air deflection torus, the volute being made of metallic material and the torus made of thermoplastic material filled with non-metallic elements, the thermoplastic material having a thermal expansion corresponding to that of the metallic material.

An internal combustion engine is provided with a pre-chamber provided inside a main combustion chamber. The pre-chamber includes an ignition plug, and a casing provided to a ceiling part to cover the ignition plug, the casing isolating an internal space formed therein from the main combustion chamber. A tumble flow of a mixture gas is formed inside the main combustion chamber. A plurality of communicating holes are formed in the casing, and include a first communicating hole opening to an intake port side and a second communicating hole opening to an exhaust port side. The tumble flow flowing into the pre-chamber through the first communicating hole forms in the pre-chamber a vortex flowing in the opposite direction from the tumble flow. The main combustion chamber is provided with a structure configured to suppress a flow opposing the vortex flowing into the pre-chamber through the second communicating hole.

The present invention uses an improved engineered metal seal with or without an internal energized spring that is disposed in a pre-combustion chamber apparatus assembly to improve sealing over the flat washer seals that are currently used. The seals of the present invention comprise at least three different geometrical configurations of seals that are manufactured from titanium, Inconel, and/or hastelloy. The design of the tip and body of the pre-combustion chamber provide for movement of the seal without leaking. The sealing is provided on the axial surfaces of the tip and the body instead of the face of the tip and body by a flat washer seal, as is currently done.

Embodiments of the present invention provide a pre-combustion chamber assembly, comprising (a) a body, having a cylindrical end portion having a step-wise increase in diameter forming a sealing surface for sealing to an engine; (b) a tip, with a hollow shaft in fluid communication with a combustion region of the tip, where the shaft has a first shaft diameter that allows the shaft to be slid over a portion of the body; (c) a gasket mounted about the body and resting against the sealing surface, wherein the gasket comprises a wire wound washer.