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 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 variable geometry turbocharger includes: a turbine rotor; and a variable nozzle mechanism for adjusting a flow of exhaust gas to the turbine rotor from a scroll flow passage formed on a radially outer side of the turbine rotor. The variable nozzle mechanism includes: a nozzle vane disposed in an exhaust gas flow passage for guiding the exhaust gas to the turbine rotor from the scroll flow passage; a support wall forming a flow passage wall on a first side of the exhaust gas flow passage with respect to an axial direction of the turbine rotor and supporting the nozzle vane rotatably in a cantilever fashion; and a non-support wall forming a flow passage wall on a second side of the exhaust gas flow passage with respect to the axial direction. Of an end surface of the nozzle vane on a side of the non-support wall, an edge portion on a side of a pressure surface includes a non-support-wall side linear portion formed to have a linear shape.

Abstract: The present invention includes: a turbine wheel 24 that is attached to a rotating shaft 14 and that has a plurality of turbine blades in the circumferential direction; scroll passages 15Aa, 15Ab that are formed in a spiral shape on the outside of the turbine wheel 24, and that are formed by being divided into a plurality of sections in the circumferential direction, the passages communicating with each other at the position of the turbine wheel 24 disposed between respective tongue sections 15Ac, 15Ad; and threads 51 that are provided on an back facing surface 41 disposed so as to oppose the back surface of the turbine wheel 24, the back surface being on the axially opposite side from the turbine blade side, and the linear parts extending from starting points 51a near the tongue sections 15Ac, 15Ad toward the rotating shaft 14 side so as to control the passage of fluid between the back surface and the back facing surface 41.

Abstract: A variable geometry turbocharger includes: a turbine rotor; and a variable nozzle mechanism for adjusting a flow of exhaust gas to the turbine rotor from a scroll flow passage formed on a radially outer side of the turbine rotor. The variable nozzle mechanism includes: a nozzle vane disposed in an exhaust gas flow passage for guiding the exhaust gas to the turbine rotor from the scroll flow passage; a support wall forming a flow passage wall on a first side of the exhaust gas flow passage with respect to an axial direction of the turbine rotor and supporting the nozzle vane rotatably in a cantilever fashion; and a non-support wall forming a flow passage wall on a second side of the exhaust gas flow passage with respect to the axial direction. Of an end surface of the nozzle vane on a side of the non-support wall, an edge portion on a side of a pressure surface includes a non-support-wall side linear portion formed to have a linear shape.

Abstract: The present invention includes: a turbine wheel 24 that is attached to a rotating shaft 14 and that has a plurality of turbine blades in the circumferential direction; scroll passages 15Aa, 15Ab that are formed in a spiral shape on the outside of the turbine wheel 24, and that are formed by being divided into a plurality of sections in the circumferential direction, the passages communicating with each other at the position of the turbine wheel 24 disposed between respective tongue sections 15Ac, 15Ad; and threads 51 that are provided on an back facing surface 41 disposed so as to oppose the back surface of the turbine wheel 24, the back surface being on the axially opposite side from the turbine blade side, and the linear parts extending from starting points 51a near the tongue sections 15Ac, 15Ad toward the rotating shaft 14 side so as to control the passage of fluid between the back surface and the back facing surface 41.

Abstract: An object is to is to reduce a leakage flow by reducing a clearance between an end surface of a nozzle vane, forming a variable nozzle mechanism of a variable geometry turbocharger, and a wall surface facing the end surface, and prevent the nozzle vane from being stuck due to contact of the end surface.

Abstract: A valve, which is provided in an exhaust passage of an internal combustion engine to release exhaust, includes a valve seat having an opening opened to the exhaust passage, a valve body having a conical surface or a spherical surface configured to close the opening by coming into contact with the valve seat, a movement unit configured to move the valve body in a direction of intersecting the opening, and an urging unit configured to urge the valve body in the direction of intersecting the opening, and the urging unit controls urging force by the movement unit in a direction of suppressing vibration of the valve body caused by vibration of exhaust pulse frequency determined by a speed of the internal combustion engine and a number of cylinders of the internal combustion engine.

Abstract: A turbocharger comprises: a rolling bearing provided with a plurality of rolling elements arranged between a raceway formed on an inner ring and a raceway formed on an outer ring; and a housing for holding the outer ring. The housing is provided with: a first dam for restricting the outflow of a lubricant through a first discharge passage for discharging the lubricant from the outer ring; and a second dam for restricting the outflow of the lubricant through a second discharge passage for discharging the lubricant from an opening formed so as to be in communication with an axially intermediate portion of the outer ring and with a peripheral wall of a space.

Abstract: In a variable geometry turbocharger including a variable nozzle mechanism, an object is to enhance safety upon malfunction of the variable nozzle mechanism as well as to improve accuracy in the control of the variable nozzle mechanism by applying a moment that acts on the nozzle vanes in an opening direction securely and stably.

Abstract: A turbocharger comprises: a rolling bearing provided with a plurality of rolling elements arranged between a raceway formed on an inner ring and a raceway formed on an outer ring; and a housing for holding the outer ring. The housing is provided with: a first dam for restricting the outflow of a lubricant through a first discharge passage for discharging the lubricant from the outer ring; and a second dam for restricting the outflow of the lubricant through a second discharge passage for discharging the lubricant from an opening formed so as to be in communication with an axially intermediate portion of the outer ring and with a peripheral wall of a space.

Abstract: An object is to provide an air intake duct structure for a centrifugal fluid machine, capable of swirling the fluid introduced into the impeller in the reverse direction to increase the pressure ratio when the flow rate is high and swirling the fluid in the forward direction to avoid a surging when the flow rate is low, as well as securing a wide operating range, without using mechanical means. The centrifugal fluid machine 1 includes an impeller 12 mounted to a rotation shaft and a housing 4 for housing the impeller 12. The air intake duct structure 10 is for directing a fluid “f” to a rotational center 12a of the impeller 12 housed in the housing 4 via an intake duct portion 4a of the housing 4 protruding in an axial direction of the rotation shaft, the fluid “f” flowing in a substantially orthogonal direction to a rotational axis line 3.

Abstract: An object is to provide a radial turbine blade that can reduce an impact loss of inflowing gas at a leading edge of the turbine blade and achieve a higher turbine efficiency, even in a case of a flow field corresponding to a low turbine operational velocity ratio U/C0 due to a throttling operation on a variable nozzle mechanism of a variable geometry turbocharger. In a radial turbine blade, a hub-side end portion Pa at a leading edge 51 of a turbine blade 50 is formed to be positioned more on a rear side in a rotation direction R of the turbine blade 50 than a shroud-side end portion Sc at the leading edge 51, and a straight line connecting between the shroud-side end portion Sc and the hub-side end portion Pa is inclined with respect to a straight line extending in a rotation axis direction from the shroud-side end portion Sc at the leading edge 51 onto a hub 17 surface by an angle in a range from 30° to 70° as viewed in the radial direction of the turbine blade 50.

Abstract: An object is to is to reduce a leakage flow by reducing a clearance between an end surface of a nozzle vane, forming a variable nozzle mechanism of a variable geometry turbocharger, and a wall surface facing the end surface, and prevent the nozzle vane from being stuck due to contact of the end surface.

Abstract: An object is to provide a radial turbine blade that can reduce an impact loss of inflowing gas at a leading edge of the turbine blade and achieve a higher turbine efficiency, even in a case of a flow field corresponding to a low turbine operational velocity ratio U/C0 due to a throttling operation on a variable nozzle mechanism of a variable geometry turbocharger. In a radial turbine blade, a hub-side end portion Pa at a leading edge 51 of a turbine blade 50 is formed to be positioned more on a rear side in a rotation direction R of the turbine blade 50 than a shroud-side end portion Sc at the leading edge 51, and a straight line connecting between the shroud-side end portion Sc and the hub-side end portion Pa is inclined with respect to a straight line extending in a rotation axis direction from the shroud-side end portion Sc at the leading edge 51 onto a hub 17 surface by an angle in a range from 30° to 70° as viewed in the radial direction of the turbine blade 50.

Abstract: In a variable geometry turbocharger including a variable nozzle mechanism, an object is to enhance safety upon malfunction of the variable nozzle mechanism as well as to improve accuracy in the control of the variable nozzle mechanism by applying a moment that acts on the nozzle vanes in an opening direction securely and stably.

Abstract: An object is to provide an air intake duct structure for a centrifugal fluid machine, capable of swirling the fluid introduced into the impeller in the reverse direction to increase the pressure ratio when the flow rate is high and swirling the fluid in the forward direction to avoid a surging when the flow rate is low, as well as securing a wide operating range, without using mechanical means. The centrifugal fluid machine 1 includes an impeller 12 mounted to a rotation shaft and a housing 4 for housing the impeller 12. The air intake duct structure 10 is for directing a fluid “f” to a rotational center 12a of the impeller 12 housed in the housing 4 via an intake duct portion 4a of the housing 4 protruding in an axial direction of the rotation shaft, the fluid “f” flowing in a substantially orthogonal direction to a rotational axis line 3.

Abstract: A valve, which is provided in an exhaust passage of an internal combustion engine to release exhaust, includes a valve seat having an opening opened to the exhaust passage, a valve body having a conical surface or a spherical surface configured to close the opening by coming into contact with the valve seat, a movement unit configured to move the valve body in a direction of intersecting the opening, and an urging unit configured to urge the valve body in the direction of intersecting the opening, and the urging unit controls urging force by the movement unit in a direction of suppressing vibration of the valve body caused by vibration of exhaust pulse frequency determined by a speed of the internal combustion engine and a number of cylinders of the internal combustion engine.

Abstract: A compressor of an exhaust gas turbocharger has a compressor housing of a divided type that forms an inlet slit, an outlet slit and a recirculation passage at the same time when the compressor housing is assembled. In the compressor of the exhaust gas turbocharger, mating surfaces of compressor housing members 9a and 9b are formed in the neighborhood of the inlet part of the impeller 5 in the compressor housing 9 that is divided into the compressor housing members 9a and 9b in the direction of the rotation axis of the impeller; and, a space forming the recirculation passage 29, an inlet slit 25 and an outlet slit 27 are formed between the mating compressor housing members 9a and 9b.

Abstract: An exhaust-bypass valve capable of reducing wear of a rotating shaft to prevent controllability from deteriorating is provided. An exhaust-bypass valve (1) of a turbocharger includes a shunting passage (5) that communicates between a passage (3) at the turbine-inlet side and a passage (4) at the turbine-outlet side and a valve flap (6) that opens and closes this shunting passage (5). The valve flap (6) opens and closes to shunt a gas flowing through the passage (3) at the turbine-inlet side into the passage at the turbine-outlet side. The valve flap (6) is rotatably supported at one side thereof serving as a center-of-rotation side, and the other side thereof moves away from or towards the shunting passage (5) to open or close the shunting passage (5). A tapered portion (10) is provided at an edge on the other side. The edge is at least one of an edge of an opening of the shunting passage (5) facing the valve flap (6) and a side surface of the valve flap (6) facing the shunting passage (5).