Abstract: In a centrifugal compressor, a diffuser channel includes a curved channel portion that bends toward a front side in an axial direction of an impeller as it goes toward an outer side in a radial direction of the impeller. In a cross-section along a rotation axis of the impeller, when a center line of the diffuser channel is A, a straight line orthogonal to the center line A at an outlet of the diffuser channel is B, and an angle between the rotation axis of the impeller and the straight line B is ?, ??60° is satisfied.

Abstract: A centrifugal compressor comprises: an impeller; an inlet pipe portion forming an intake passage to introduce air to the impeller; and a throttle mechanism capable of reducing a flow passage area of the intake passage upstream of the impeller. When PA is a throttle position where the throttle mechanism minimizes the flow passage area of the intake passage, PB is a tip position of a leading edge of a blade of the impeller, L is a distance between the throttle position PA and the tip position PB of the leading edge in an axial direction of the impeller, and D is a diameter of the impeller at the tip position PB of the leading edge, the distance L and the diameter D satisfy L/D?0.2.

Abstract: A scroll shape of a compressor forms into a spiral shape a flow path of fluid discharged from a diffuser provided on a downstream side of the compressor in a fluid flow direction. The scroll shape has a scroll outer diameter that is not constant in a circumferential direction. An increase degree of a ratio A/R is set to be increased in a range from a winding start position to a winding end position of a scroll portion where A is a passage cross-sectional area of the scroll portion and R is a radius from a center of the compressor to a center of a passage cross section of the scroll portion.

Abstract: A centrifugal compressor comprises: an impeller; an inlet pipe portion forming an intake passage to introduce air to the impeller; and a throttle mechanism capable of reducing a flow passage area of the intake passage upstream of the impeller. The throttle mechanism includes an annular portion configured to move between a first position and a second position upstream of the first position in an axial direction of the impeller. In a cross-section along a rotational axis of the impeller, an outer peripheral surface of the annular portion is formed to smoothly connect a leading edge and a trailing edge of the annular portion.

Abstract: A compressor wheel device comprises a compressor wheel attached to a rotary shaft and a thrust collar attached to the rotary shaft at a back surface of the compressor wheel. The compressor wheel includes: a wheel body part with a hub and at least one blade provided on an outer peripheral surface of the hub; and a sleeve part having a cylindrical shape projecting along an axis direction from a back surface of the hub and having an outer peripheral surface on which a sealing groove extending along a peripheral direction is formed. The thrust collar has a circular plate-like shape including: one surface including an abutting surface abutting on an end surface of the sleeve part and extending along a radial direction; and the other surface including a slidably-contacting surface slidably contacting a thrust bearing supporting the rotary shaft in a thrust direction and extending along the radial direction.

Abstract: A centrifugal compressor includes: an impeller; an inlet pipe portion forming an intake passage to introduce air to the impeller; and a throttle mechanism capable of reducing a flow passage area of the intake passage upstream of the impeller. The throttle mechanism includes an annular portion configured to move between a first position and a second position upstream of the first position in an axial direction of the impeller, and a strut supporting the annular portion. The strut extends toward at least one of an outer side in a radial direction of the impeller or a downstream side in the axial direction of the impeller with an increase in distance from the annular portion.

Abstract: A centrifugal compressor includes an impeller rotatably disposed and having a plurality of first blades and a shroud cover disposed on a leading edge side of the first blades partially in a rotational axis direction of the impeller and connecting the first blades circumferentially adjacent to each other. The shroud cover is shaped such that a position of at least one of an upstream edge or a downstream edge of the shroud cover in the rotational axis direction changes along a circumferential direction of the shroud cover.

Abstract: A vaned diffuser provided on a downstream side of an impeller of a centrifugal compressor. The vaned diffuser includes: a diffuser passage forming portion having a hub-side surface and a shroud-side surface and forming an annular diffuser passage on a downstream side of the impeller; and a plurality of diffuser vanes provided in the diffuser passage at intervals in a circumferential direction of the impeller. A fillet is formed in a connection portion between each of the diffuser vanes and at least one of the hub-side surface and the shroud-side surface. Also, where R is a radius of the fillet and b is a vane height of each of the diffuser vanes, and a maximum value of R/b on a downstream side of a throat position of the diffuser passage is larger than a maximum value of R/b on an upstream side of the throat position of the diffuser passage.

Abstract: Provided is a supercharger (11) comprising: a hollow housing (15); a rotating shaft (14) rotatably supported by the housing (15); a turbine (12) provided at one axial end of the rotating shaft (14); and a compressor (13) provided at the other axial end of the rotating shaft (14). A threaded section (41) and a circular column section (42) are axially arranged at the other end of the rotating shaft (14). A threaded hole (43) with which the threaded section (41) is engaged and a fitting hole (44) in which the circular column section (42) is fitted are axially arranged in the compressor (13). The axial length of the circular column section (42) and the fitting hole (44) is set to be greater than the axial length of the threaded section (41) and the threaded hole (43).

Abstract: A centrifugal compressor includes an impeller, a plurality of diffuser vanes arranged in a circumferential direction on a radially outer side of the impeller, and a housing which includes a scroll portion forming a scroll flow passage positioned on a radially outer side of the plurality of diffuser vanes. The plurality of diffuser vanes include at least one first diffuser vane positioned in an angular range between a tongue section of the scroll portion and a scroll end of the scroll portion in the circumferential direction, and a second diffuser vane positioned outside the angular range. A vane outlet angle formed by a tangent line at a trailing edge to a pressure surface of each of the plurality of diffuser vanes satisfies ?1<?2, where ?1 is the vane outlet angle of the first diffuser vane, and ?2 is the vane outlet angle of the second diffuser vane.

Abstract: A centrifugal compressor includes an impeller; a compressor cover including at least an inlet pipe portion having an intake air flow path formed for sending gas to the impeller; a movable member disposed inside the compressor cover so as to be movable along a direction of an axis of the impeller; and a movement mechanism configured to move the movable member along the direction of the axis of the impeller, the movement mechanism moving the movable member in the direction of the axis to bring the movable member and an inner wall surface of the compressor cover into contact with each other. At least one of the compressor cover and the movable member has a contact portion configured of an abradable sealing material or a high-elasticity plastic material at which the compressor cover and the movable member come into contact with each other.

Abstract: A centrifugal compressor includes an impeller including a hub and a plurality of blades disposed on an outer peripheral surface of the hub at intervals in a circumferential direction, and a casing accommodating the impeller and defining an inlet passage for introducing air along an axial direction of the impeller. An inner peripheral surface of the inlet passage includes a narrowed portion, and an inclined portion connected to a downstream side of the narrowed portion and having a radial distance from a rotational axis of the impeller gradually increasing toward the vicinity of tips of leading edges of the blades. Further, 0.01R1???0.1R1 is satisfied, where R1 is radial distance between a downstream end of the inclined portion and the rotational axis, R2 is radial distance between a downstream end of the narrowed portion and the rotational axis, and ? is constriction amount which is a difference between R1 and R2.

Abstract: A compressor impeller includes an impeller body which includes a boss portion and a plurality of compressor blades disposed on an outer peripheral surface of the boss portion, and a connection portion which is disposed on a side of a back surface of the impeller body and is configured to be connectable to one end of a rotational shaft. A ratio D1/D2 satisfies 0.18 or less, where D1 is a diameter of the boss portion on leading edges of the compressor blades, and D2 is a maximum outer diameter of the compressor blades.

Abstract: A compressor housing accommodating a compressor wheel for compressing intake air supplied to an engine has therein an outer cooling passage extending along a circumferential direction on an outer circumferential side of a scroll passage of a spiral shape through which the intake air compressed by the compressor wheel flows, and an inner cooling passage extending along the circumferential direction on an inner circumferential side of the scroll passage. The inner cooling passage is separated from the outer cooling passage by a separation wall extending along the circumferential direction.

Abstract: A surging precursor detecting device is a surge detecting device configured to detect a precursor of a surge of a compressor including a housing portion housing a blade including a rotary blade of an impeller and configured to compress a fluid supplied from an inlet piping portion and discharge the fluid to an outlet piping portion. The surging precursor detecting device includes an acquisition unit configured to acquire time series data of a state quantity having a correlation with internal pressure in at least one position of an inlet piping position, an outlet piping position, and an intermediate position between the inlet piping position and the outlet piping position, an analysis unit configured to perform a chaotic time series analysis on the time series data with the number of embedded dimensions being not less than three, and a detecting unit configured to detect a precursor of the surge.

Abstract: The present invention is provided with: an annular hub 7 having a circularly formed axial cross-section; a plurality of first blades 8 that are arranged on the outer circumferential surface of the hub 7; and a plurality of second blades 9 that are arranged closer to the downstream-side in the flow direction of fluid than the rear edges 8b of the first blades 8, in the outer circumferential surface of the hub 7, wherein the number of the second blades 9 is less than a double that of the first blades 8.

Abstract: A compressor comprises: a rotor including a hub and a blade provided on an outer peripheral surface of the hub; and a casing surrounding the rotor so as to face a tip of the blade across a gap. Provided that the gap between the tip of the blade and the casing has a size t0 at a leading edge of the blade, the gap between the tip of the blade and the casing has a size larger than t0 in at least a partial range downstream of the leading edge in an axial direction of the rotor.

Abstract: A scroll casing forms a scroll flow passage of a centrifugal compressor, and provided that, in a cross section of the scroll flow passage, Ei is an inner end of the scroll flow passage in a radial direction of the centrifugal compressor, and Mh is a middle point of a maximum flow-passage height Hmax of the scroll flow passage in the axial direction of the centrifugal compressor, the scroll flow passage has a separation suppressing cross section in which the inner end Ei is disposed on an inner side, in the radial direction, of a diffuser outlet, and the inner end Ei is disposed on a back side, in the axial direction, of the middle point Mh, in a section disposed at least partially in an upstream region of a connection position of a scroll start and a scroll end.

Abstract: An inclination angle between a direction perpendicular to a rotational axis and a tangential direction of a radially outer edge of a radially outermost concave arc portion, which is located outermost in the radial direction of an impeller among at least one concave arc portion, has a distribution along the circumferential direction of a scroll passage, and when a circumferential position in the scroll passage from a tongue of a scroll part to an outlet of the scroll passage is represented by a central angle about the rotational axis by using the tongue as a reference, the distribution of the inclination angle has a local minimum value or a minimum value in a range of the central angle of 30° to 210°.

Abstract: A compressor scroll (1A) is provided with: a scroll-flow-path formation part (8A) that forms a scroll flow path; and an outlet-flow-path formation part (9) that is connected to a winding-end section (11) of a scroll flow path (8a) and that forms an outlet flow path (9a) extending in a direction tangential to a circle around an axis (O), wherein, at least at the winding-end section (11) in an area where a winding-start section (10) intersects with the winding-end section (11), the scroll-flow-path formation part (8A) is provided with a bulging part (15A) that bulges the scroll flow path in the radial direction toward the side where the winding-start section (10) is present.