Hitachi, Ltd.

Saburo Iwasaki

Yoshihiro Nagaoka

Sadashi Tanaka

Yukiji Iwase

Michiaki Ida

Yoshiharu Ueyama

Hirotoshi Ishimaru

Tetuya Yoshida

At a vaned diffuser or a volute casing of a centrifugal fluid machine, pressure pulsation and vibrating forces acting upon the diffuser or the volute casing are mitigated or cancelled so as to abate the noise from the centrifugal fluid machine. The fluid machine having an impeller rotating about a rotating shaft within a casing and having a vaned diffuser or volute fixed to the casing is constructed such that radius of the vane trailing edge of the impeller and radius of the vane leading edge of the diffuser or radius of the volute tongue is varied in the direction of axis of rotation and inclinations, on a meridional plane, of the vane trailing edge of the impeller and the vane leading edge of the diffuser or the volute tongue are set in the same orientation, thereby reduction in head and efficiency or occurrence of an axial thrust may be restrained to the extent possible to optimally abate the noise and pressure pulsation of the centrifugal fluid machine.

Centrifugal fluid machine

At a volute casing of a centrifugal fluid machine, pressure pulsation and vibrating forces acting upon the volute casing are mitigated or cancelled so as to abate the noise from the centrifugal fluid machine. The fluid machine having an impeller,rotating about a rotating shaft,within a casing,and having a volute,fixed to the casing,is constructed such that radius of the vane trailing edge of the impeller,and radius of the volute tongue is varied in the direction of axis of rotation and inclinations, on a meridional plane, of the vane trailing edge of the impeller,and the vane leading edge of the volute tongue are set in the same orientation, thereby reduction in head and efficiency or occurrence of an axial thrust may be restrained to the extent possible to optimally abate the noise and pressure pulsation of the centrifugal fluid machine.

At a vaned diffuser or a volute casing of a centrifugal fluid machine, pressure pulsation and vibrating forces acting upon the diffuser or the volute casing are mitigated or cancelled so as to abate the noise from the centrifugal fluid machine. The fluid machine having an impeller,rotating about a rotating. shaft,within a casing,and having a vaned diffuser,or volute,fixed to the casing,is constructed such that radius of the vane trailing edge of the impeller,and radius of the vane leading edge of the diffuser,or radius of the volute tongue is varied in the direction of axis of rotation and inclinations, on a meridional plane, of the vane trailing edge of the impeller,and the vane leading edge of the diffuser,or the volute tongue are set in the same orientation, thereby reduction in head and efficiency or occurrence of an axial thrust may be restrained to the extent possible to optimally abate the noise and pressure pulsation of the centrifugal fluid machine.

At a vaned diffuser or a volute casing of a centrifugal fluid machine, pressure pulsation and vibrating forces acting upon the diffuser or the volute casing are mitigated or cancelled so as to abate the noise from the centrifugal fluid machine. The fluid machine having an impeller 3 rotating about a rotating shaft 2 within a casing 1 and having a vaned diffuser 4 or volute 12 fixed to the casing 1 is constructed such that radius of the vane trailing edge of the impeller 3 and radius of the vane leading edge of the diffuser 4 or radius of the volute tongue is varied in the direction of axis of rotation and inclinations, on a meridional plane, of the vane trailing edge of the impeller 3 and the vane leading edge of the diffuser 4 or the volute tongue are set in the same orientation, thereby reduction in head and efficiency or occurrence of an axial thrust may be restrained to the extent possible to optimally abate the noise and pressure pulsation of the centrifugal fluid machine.

At a volute casing of a centrifugal fluid machine, pressure pulsation and vibrating forces acting upon the diffuser or the volute casing are mitigated or cancelled so as to abate the noise from the centrifugal fluid machine. The fluid machine having an impeller 3 rotating about a rotating shaft 2 within a casing 1 and having a volute 12 fixed to the casing 1 is constructed such that radius of the vane trailing edge of the impeller 3 and radius of the volute tongue is varied in the direction of axis of rotation and inclinations, on a meridional plane, of the vane trailing edge of the impeller 3 and the leading edge of the volute tongue are set in the same orientation, thereby reduction in head and efficiency or occurrence of an axial thrust may be restrained to the extent possible to optimally abate the noise and pressure pulsation of the centrifugal fluid machine.

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Tsuchiura, Japan

Saburo Iwasaki