Abstract: In a scroll structure for a radial turbine configured such that a turbine rotor 02 is rotationally driven by causing exhaust gas to flow from a spiral scroll portion 4 formed in a turbine housing 1 toward a rotor blade 3 of the scroll portion 4 in a radial direction, and act on the rotor blade 3, then flow out in an axial direction, a heat radiation space portion is formed in a shroud portion 11 between the turbine housing 1 and a turbine chamber provided with the rotor blade 3.

Abstract: In a turbine scroll part structure of a radial turbine, a flow passage 3 of a connecting part between an exhaust gas inlet into a turbine housing 5 and a scroll part 1 is offset along an axis line L1 of a rotating shaft of a turbine rotor in an amount H, and a cut-out portion P is formed in a tongue portion 2, which separates the flow passage 3 from a blade side passage 4 through which the exhaust gas flows toward blades 6, for the exhaust gas to flow from the flow passage 3 into the blade side passage 4.

Abstract: A turbine wheel includes a plurality of blades having a scallop cut-out profile. The scallop cut-out profile is formed by cutting-out a back side wall part of the blade between the suction surface side of a blade part and the pressure surface side of the adjacent blade.

Abstract: A sheet-metal turbine housing has a scroll part formed by joining opposing scroll members of sheet metal to form a spiral-shaped exhaust gas passage. The housing includes a member on a side of a bearing housing inclosing a bearing supporting a rotation shaft of a turbine rotor blade member on the exhaust side forms an outer side of the turbine rotor blade. Support columns connect the member on the side of the bearing housing with the member on the exhaust side in an axial direction of the turbine and are arranged at intervals on an outer circumference of the turbine. Each support columns may have a cross-sectional shape which includes an upstream corner and a downstream corner in a direction of a gas flow, each of which has an acute angle, so that an upstream surface and a downstream surface are inclined to the gas flow.

Abstract: Providing a turbine rotor in which the rotational inertia of the turbine rotor can be reduced without changing the geometry of the blade part, whereas the turbine rotor is provided with the rear side surface so that the stress concentration appearing at the root part regarding the hub part on the rear surface side is constrained in order that the strength and the durability of the turbine rotor can be enhanced.

Abstract: A turbine rotor of a turbine includes a hub that serves as an axis of rotation, and a plurality of turbine blades. The turbine blades each have a line extending along a shroud-side edge of the turbine blade from the inlet to the outlet as a shroud line. The shroud line includes an entrance-side shroud line La that makes a small change from the inlet toward the outlet in a blade angle with respect to the axis of rotation, a center shroud line Lb that extends from the outlet side of the entrance-side shroud line La and makes a greater change than that of the entrance-side shroud line La, and an exit-side shroud line Lc that extends from the outlet side of the center shroud line Lb to the outlet and makes a smaller change than that of the center shroud line Lb.

Abstract: A structure of a radial turbine scroll avoids a gas flow heading from a radially outer side toward a radially inner side in the vicinity of a tongue portion so as to restrain turbine performance from deteriorating and also reduces, to a maximum, thermal stress caused by the formation of the tongue portion.

Abstract: An exhaust turbo-supercharger having a high efficiency is provided. The exhaust turbo-supercharger includes therein an exhaust turbine housing including a spiral channel and a turbine-accommodating chamber connected to an innermost peripheral part of the spiral channel; an exhaust turbine provided in the turbine-accommodating chamber so that the axial line of the exhaust turbine is parallel to that of the spiral channel; a shaft that is concentrically connected to one side of the exhaust turbine in the axial line direction; a bearing housing disposed at the side of the exhaust turbine in the axial line direction so as to be adjacent to the exhaust turbine housing; a bearing that is provided in the bearing housing and that rotatably supports the shaft around the axial line; and a heat shield component interposed between the exhaust turbine housing and the bearing housing.

Abstract: An exhaust turbo-supercharger having a high efficiency is provided. The exhaust turbo-supercharger includes therein an exhaust turbine housing including a spiral channel and a turbine-accommodating chamber connected to an innermost peripheral part of the spiral channel; an exhaust turbine provided in the turbine-accommodating chamber so that the axial line of the exhaust turbine is parallel to that of the spiral channel; a shaft that is concentrically connected to one side of the exhaust turbine in the axial line direction; a bearing housing disposed at the side of the exhaust turbine in the axial line direction so as to be adjacent to the exhaust turbine housing; a bearing that is provided in the bearing housing and that rotatably supports the shaft around the axial line; and a heat shield component interposed between the exhaust turbine housing and the bearing housing.

Abstract: A trailing edge of a turbine rotor blade is formed so that a deflection angle of a blade surface in a downstream side of a maximum blade thickness portion is a predetermined value or less, by forming the trailing edge of the rotor blade so as to be inclined from a center line of a blade thickness toward an extension line of a suction surface. Since the trailing edge of the rotor blade is thus formed, a rapid increase of the deflection angle is prevented in a trailing edge portion of the rotor blade. Accordingly, a rapid ascent portion and a rapid deceleration portion are not generated in a suction surface velocity in a main stream unlike the conventional case.

Abstract: A radial turbine impeller is provided, comprising a circular main disk provided with a plurality of blades, each having a negative pressure surface and a positive pressure surface; scallops being formed by cutting off the main disk between the negative pressure surface of the one blade and the positive pressure surface of the other blade adjacent to the one blade, respectively; wherein a minimum radius portion of the scallop having a minimum distance between a center of the circular main disk and the edge of the scallop is positioned closer to the positive pressure surface so that the scallop is asymmetric between the negative pressure surface of the one blade and the positive pressure surface of the other blade adjacent thereto.

Abstract: A radial turbine impeller is provided, comprising a circular main disk provided with a plurality of blades, each having a negative pressure surface and a positive pressure surface; scallops being formed by cutting off the main disk between the negative pressure surface of the one blade and the positive pressure surface of the other blade adjacent to the one blade, respectively; wherein a minimum radius portion of the scallop having a minimum distance between a center of the circular main disk and the edge of the scallop is positioned closer to the positive pressure surface so that the scallop is asymmetric between the negative pressure surface of the one blade and the positive pressure surface of the other blade adjacent thereto. It is possible to prevent the turbine efficiency from lowering due to the impingement of a fluid onto the edge of the scallop.

Abstract: A support pin (24) is disposed at a position in front of a front edge (19a) of a movable nozzle blade (19) in a state in which the movable nozzle blade (19) is located at a rating opening position B, set between a maximum opening position A and a minimum opening position C. The aerodynamic effect of the support pin when the flow rate is small is thus reduced, and the turbine efficiency when the flow rate is small is enhanced.

Abstract: The improvements are made in the turbine scroll and the turbine blades. The scroll structure for the radial turbines is characterized by the foregoing scroll having a scroll width ratio between the width in the radial direction (&Dgr;R) and the width in the direction of the rotation (B) ranging from &Dgr;R/B=0.3 to 0.7. It is further characterized by the configuration in which the turbine blades have cut-away areas at the blade corners by a prescribed amount, which are provided on the inlet edge at the shroud side and hub side where the operating gas flows.

Abstract: A trailing edge of a turbine rotor blade is formed so that a deflection angle of a blade surface in a downstream side of a maximum blade thickness portion is a predetermined value or less, by forming the trailing edge of the rotor blade so as to be inclined from a center line of a blade thickness toward an extension line of a suction surface. Since the trailing edge of the rotor blade is thus formed, a rapid increase of the deflection angle is prevented in a trailing edge portion of the rotor blade. Accordingly, a rapid ascent portion and a rapid deceleration portion are not generated in a suction surface velocity in a main stream unlike the conventional case.

Abstract: The improvements are made in the turbine scroll and the turbine blades. The scroll structure for the radial turbines is characterized by the foregoing scroll having a scroll width ratio between the width in the radial direction (&Dgr;R) and the width in the direction of the rotation (B) ranging from &Dgr;R/B=0.3 to 0.7. It is further characterized by the configuration in which the turbine blades have cut-away areas at the blade corners by a prescribed amount, which are provided on the inlet edge at the shroud side and hub side where the operating gas flows.

Abstract: By disposing a support pin (24) at a position in front of a front edge (19a) of a movable nozzle blade (19) in a state in which the movable nozzle blade (19) is located at a rating opening position B set between a maximum opening position A and a minimum opening position C, aerodynamic affect of the support pin when flow rate is small is reduced, and a turbine efficiency when the flow rate is small is enhanced.