Honda Motor Co., Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Naoki Kuno

Naoki Itoh

Takashi Sakakibara

Shuichi Honda

Toyotaka Sonoda

Mineyasu Oana

Gensuke Hoshino

Hidehiko Nakata

A cooling structure for a radial turbine is equipped with a partition wall arranged between a compressor and the radial turbine, and a through hole formed in the partition wall supplying a part of air compressed by the compressor to the rear surface of the radial turbine as cooling air. The through hole is inclined in a rotational direction of the radial turbine in the range of 40° to 80° with respect to a rotation axis of the radial turbine.

Cooling structure for radial turbine

A radial turbine impeller includes full blades and splitter blades arranged alternately in the rotational direction of the radial turbine impeller, the splitter blades having a shorter blade length in a fluid flow direction in the radial turbine impeller than the full blades. A throat is provided between each two of the full blades adjacent to each other in the rotational direction. A part of a downstream edge of each splitter blade on a side of a base edge which is joined to an outer peripheral surface of a hub is positioned upstream of the throat, and a part of the downstream edge of each splitter blade on a side of a tip edge which is remote from the outer peripheral surface of the hub is positioned downstream of the part of the downstream edge on the side of the base edge.

Radial turbine impeller

A turbine () includes: a turbine impeller chamber () having a tubular outflow portion (), from which an exhaust gas flows out in an outflow direction (F) substantially parallel to an axis (C) of a turbine impeller (); a bypass flow passage () bypassing the inside of the turbine impeller chamber; an outer duct () having an inner peripheral surface () that expands in diameter in the outflow direction from the outflow portion; and an inner duct () that extends in the outflow direction from the outflow portion. A diffuser flow passage () that expands in diameter in the outflow direction is disposed in the inner duct at least in a portion between the outflow portion and a distal end portion (). An outlet () of the bypass flow passage and a waste gate valve () that opens and closes the outlet are disposed on the inner peripheral surface.

Turbine

A compressor includes an impeller having a rotational axis. An annular diffuser is provided around the rotational axis to surround the impeller in order to decelerate the fluid discharged from the impeller in a centrifugal direction with respect to the rotational axis. The annular diffuser includes first vanes and second vanes. The first vanes are arranged in a first blade row extending in a circumferential direction around the rotational axis such that two adjacent vanes among the first vanes do not define a throat therebetween viewed along the rotational axis. The second vanes are arranged in a second blade row which extends in the circumferential direction and which is provided farther than the first blade row in the centrifugal direction from the rotational axis. A number of the second vanes is two times or more as large as a number of first vanes.

Compressor with annular diffuser having first vanes and second vanes

The effective efficiency of a centrifugal compressor can be improved by achieving a uniform distribution of fluid velocity across the outlet end of a fluid passage of an axial diffuser for the centrifugal compressor and a high static pressure recovery ratio Cp in the axial diffuser passage. The cross section of each axial diffuser passage is configured such that a relatively high velocity fluid flow in an upstream part of the diffuser passage is directed toward a negative pressure side of a cross section thereof. It can be accomplished by directing a minor axis of a cross section of the diffuser passage substantially perpendicularly to a direction directed from a center of the cross section of the diffuser passage to the central axial line of an impeller or directing the minor axis toward the central axial line of the impeller.

Axial diffuser for a centrifugal compressor

In a stator vane arrangement including a plurality of stator vanes axially opposing a plurality of rotor vanes in rotating machinery, each stator vane is tilted with respect to a radial line so that the load acting on the hub end of each stator vane is reduced and a secondary flow is minimized. This allows the aspect ratio of each stator vane to be reduced, and the number of stator vanes to be reduced without impairing the efficiency of the rotating machinery. This in turn allows the frequency of the oscillator force produced by the stator vane in relation with the motion of the rotor vanes to be lowered so that a resonant condition of the stator vanes can be avoided relatively easily.

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Wako, Japan

Naoki Kuno