Diaphragm and centrifugal rotating machine

Abstract

A diaphragm rotatably covers an impeller around an axis. A diaphragm has a suction flow channel configured to supply a gas toward an inlet of an impeller, a diffuser flow channel through which the gas discharged from the impeller outward in a radial direction flows, and a communication section configured to bring the suction flow channel and the diffuser flow channel in constant communication with each other.

1 . (canceled) 
     
     
         2 . A diaphragm configured to rotatably cover an impeller about an axis, the diaphragm having:
 an inlet-side flow channel configured to supply a fluid toward an inlet of the impeller;   an outlet-side flow channel through which the fluid discharged from the impeller outward in the radial direction flows;   a communication section configured to bring the inlet-side flow channel and the outlet-side flow channel in constant communication with each other;   a first vane disposed in the inlet-side flow channel and configured to guide the fluid in a desired direction; and   a second vane disposed in the outlet-side flow channel and configured to guide the fluid in a desired direction,   wherein the communication section is disposed between a position closer to an upstream side than the first vane and a position closer to a downstream side than the second vane.   
     
     
         3 . A centrifugal rotating machine comprising:
 the diaphragm according to  claim 2 ; and   an impeller configured to be supported by the diaphragm to be relatively rotatable around the axis with respect to the diaphragm.   
     
     
         4 . The centrifugal rotating machine according to  claim 3 , comprising a plurality of impellers arranged in a direction of the axis and rotated around the axis,
 wherein the diaphragm supports at least one impeller, among the plurality of impellers, in which a surge flow rate is designed to be mostly increased.   
     
     
         5 . The centrifugal rotating machine according to  claim 3 , comprising a plurality of impellers arranged in a direction of the axis and rotated around the axis,
 wherein a plurality of diaphragms are arranged in the direction of the axis to support the plurality of impellers, respectively, and   flow channel areas of the fluid in the communication sections are different in each of the diaphragms.