Honda Giken Kogyo Kabushiki Kaisha

Masato Hayama

Shunji Yano

Kazuo Inoue

Takayuki Hirayama

Hideo Yamaji

A turbocharger comprises a compressor housing, a turbine housing, and a central housing with a shaft rotatably supported therein. The shaft supports on its respective opposite ends a compressor wheel and a turbine wheel that are rotatably disposed in the compressor housing and the turbine housing, respectively. The central housing has a large water jacket near the turbine housing and substantially coextensive therewith for storing cooling water to cool bearings which support the shaft. The turbine housing accommodates a shroud including a vane holder on which fixed and movable vanes are alternately supported for directing exhaust gases to the turbine wheel through variable restrictions. The vane holder or base plate has a radially outer flange and an annular boss which position the shroud axially and radially with respect to the central housing.

Turbocharger

A radial turbine of a variable area nozzle type which is suitable for use as the exhaust turbine of a turbocharger for an automotive internal combustion engine requiring a quick response and a wide operating range. This turbine comprises at least two groups of variable area nozzles which may be, for instance, defined by moveable vanes, and can be individually controlled for each group to vary their sizes. By opening the variable area nozzles of the first group while the variable area nozzles of the second group are kept closed, a sufficient supercharging effect can be obtained even when the fluid flow rate is small. By opening the variable area nozzles of both the groups, the resistance to the fluid flow can be reduced and the creation of excessive back pressure at the inlet to the turbine can be avoided even when the fluid flow rate is large. In this way, not only the operating range of the turbine can be expanded but also the control accuracy particularly in small nozzle opening condition can be improved.

Variable area nozzle turbine

A variable-displacement turbine includes a turbine wheel, and a turbine housing accommodating a turbine wheel and having an exhaust inlet tubular member for introducing a stream of exhaust gases from an engine, top and base plates having confronting parallel annular end surfaces, respectively, concentric with the turbine wheel, the top and base plates defining a passage for supplying and guiding the stream of exhaust gases through the exhaust inlet tubular member to the turbine wheel from its outer periphery, and a vane mechanism disposed annularly in surrounding relation to the turbine wheel and between the annular end surfaces. The vane mechanism includes a plurality of drive shafts rotatably extending through the base plate and disposed at substantially equally spaced angular intervals between the annular end surfaces, the drive shafts being rotatably actuatable by an actuator, and a plurality of movable vanes extending between the annular end surfaces, the movable vanes having base end portions mounted respectively on the drive shafts in slidable contact with the base plate and wing portions extending respectively from the base end portions and spaced from the base and top plates by distances, the movable vanes being tiltable between the annular end surfaces in response to rotation of the drive shafts, respectively, for regulating the stream of exhaust gases. The movable vanes can be tilted unobstructedly even if various members are subjected to thermal strains and/or dimensional errors.

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Saitama, Japan

Masato Hayama