A reciprocating engine system includes a turbocharger system including a mechanically driven compressor, an electrically driven compressor, and a compressor bypass valve. A control system is programmed for generating control signals for: under nominal full load operating conditions, minimizing gas flow through the compressor bypass valve and compressing gas within the electrically driven compressor to maintain a speed set point or a full load power set point of the reciprocating engine system, under off nominal full load operating conditions wherein an efficiency of the mechanically driven compressor is reduced, compressing gas within the electrically driven compressor to compensate for the reduced efficiency of the mechanically driven compressor and to maintain the speed set point or the full load power set point of the reciprocating engine system, and under partial load operating conditions, partially diverting the gas flow through the compressor bypass valve in response to the reduced load.

An auxiliary power unit for an aircraft includes a rotary intermittent internal combustion engine drivingly engaged to an engine shaft, a turbine section having an inlet in fluid communication with an outlet of the engine(s), the turbine section including at least one turbine compounded with the engine shaft, and a compressor having an inlet in fluid communication with an environment of the aircraft and an outlet in fluid communication with a bleed duct for providing bleed air to the aircraft, the compressor having a compressor rotor connected to a compressor shaft, the compressor shaft drivingly engaged to the engine shaft. The driving engagement between the compressor shaft and the engine shaft is configurable to provide at least two alternate speed ratios between the compressor shaft and the engine shaft.

An auxiliary power unit for an aircraft includes a rotary intermittent internal combustion engine drivingly engaged to an engine shaft, a turbine section having an inlet in fluid communication with an outlet of the engine(s), the turbine section including at least one turbine compounded with the engine shaft, and a compressor having an inlet in fluid communication with an environment of the aircraft and an outlet in fluid communication with a bleed duct for providing bleed air to the aircraft, the compressor having a compressor rotor connected to a compressor shaft, the compressor shaft drivingly engaged to the engine shaft. The driving engagement between the compressor shaft and the engine shaft is configurable to provide at least two alternate speed ratios between the compressor shaft and the engine shaft.

A bearing housing for a turbocharger is disclosed. The bearing housing includes a first end proximate to a turbine wheel of the turbocharger and a second end proximate to a compressor wheel of the turbocharger. The bearing housing further includes a central chamber disposed between the first end and the second end and configured to house, at least, the shaft. The bearing housing further includes an oil drain disposed radially outward of the shaft and configured for directing oil out of the bearing housing and an oil core disposed radially outward of the shaft and radially inward of the oil drain, the oil core configured for communicating oil towards the oil drain and having an inner wall. The bearing housing includes one or more strakes protruding radially inward from the inner wall, the one or more strakes configured to direct oil within the oil core towards the oil drain.

A bearing housing for a turbocharger is disclosed. The bearing housing includes a first end proximate to a turbine wheel of the turbocharger and a second end proximate to a compressor wheel of the turbocharger. The bearing housing further includes a central chamber disposed between the first end and the second end and configured to house, at least, the shaft. The bearing housing further includes an oil drain disposed radially outward of the shaft and configured for directing oil out of the bearing housing and an oil core disposed radially outward of the shaft and radially inward of the oil drain, the oil core configured for communicating oil towards the oil drain and having an inner wall. The bearing housing includes one or more strakes protruding radially inward from the inner wall, the one or more strakes configured to direct oil within the oil core towards the oil drain.

A rotary machine include: a rotational shaft; an impeller mounted to the rotational shaft; an impeller housing accommodating the impeller; a bearing housing accommodating a bearing which supports the rotational shaft rotatably, the bearing housing being fastened to the impeller housing; and a fastening member fastening the impeller housing and the bearing housing in an axial direction of the rotational shaft. The impeller housing, the bearing housing, and the fastening member each includes a contact surface in a direction intersection with an axial direction of the rotational shaft. A thin-plate member formed separately from the impeller housing, the bearing housing, and the fastening member is interposed between at least two of the contact surfaces.

A rotary machine include: a rotational shaft; an impeller mounted to the rotational shaft; an impeller housing accommodating the impeller; a bearing housing accommodating a bearing which supports the rotational shaft rotatably, the bearing housing being fastened to the impeller housing; and a fastening member fastening the impeller housing and the bearing housing in an axial direction of the rotational shaft. The impeller housing, the bearing housing, and the fastening member each includes a contact surface in a direction intersection with an axial direction of the rotational shaft. A thin-plate member formed separately from the impeller housing, the bearing housing, and the fastening member is interposed between at least two of the contact surfaces.

A product may include a bearing housing in which a shaft may be supported by a bearing so that it may rotate. A compressor wheel may be disposed on the shaft. A compressor cover may be connected with the bearing housing, which may form a compressor body and may define a chamber within which the compressor wheel may rotate. A diffuser may extend radially outward from the chamber and may receive gas from the compressor wheel. An inlet may be provided to the compressor body, which may receive a supply of exhaust gas. An EGR distribution cavity may be defined within the compressor body and may extend around the shaft. An EGR inlet channel may extend into the bearing housing from the inlet to the EGR distribution cavity. An EGR passage may extend from the EGR distribution cavity to the diffuser.

A product may include a bearing housing in which a shaft may be supported by a bearing so that it may rotate. A compressor wheel may be disposed on the shaft. A compressor cover may be connected with the bearing housing, which may form a compressor body and may define a chamber within which the compressor wheel may rotate. A diffuser may extend radially outward from the chamber and may receive gas from the compressor wheel. An inlet may be provided to the compressor body, which may receive a supply of exhaust gas. An EGR distribution cavity may be defined within the compressor body and may extend around the shaft. An EGR inlet channel may extend into the bearing housing from the inlet to the EGR distribution cavity. An EGR passage may extend from the EGR distribution cavity to the diffuser.

An adjustment mechanism for an air inlet flow section of a compressor wheel of a turbocharger. The adjustment mechanism defines a variable inlet diameter for an axial air flow to the compressor wheel. The adjustment mechanism has a unison ring and a plurality of vanes. An actuator is used for providing a first pivoting motion to the unison ring about a central axis and thereby providing a second pivoting motion to the plurality of vanes. At least one elastic biaser is arranged, such that it provides, upon the pivoting motion to the unison ring, a restoring force to the unison ring and/or the plurality of vanes. The pivoting motion of the vanes adjusts the inlet diameter of the axial air flow to the compressor wheel.