Patent ID: 7942628
Filing Date: 2011-05-17
Classification: F04D,F25B

Abstract:
1. A turbo compressor comprising: (a) a first compression stage having a first centrifugal impeller and a first housing surrounding the first centrifugal impeller, wherein the first compression stage is arranged to take in fluid at an upstream portion and output compressed fluid at a downstream portion; (b) a second compression stage arranged to further compress compressed fluid from the first compression stage, the second compression stage having a second centrifugal impeller coupled to the first centrifugal impeller via a rotating shaft and a second housing surrounding the second centrifugal impeller; and (c) a connection flow path connecting the first housing and the second housing, the connection flow path arranged to introduce compressed fluid output from the first compression stage into the second compression stage, wherein the first compression stage and the second compression stage are arranged at positions adjacent each other, wherein the first centrifugal impeller and the second centrifugal impeller are arranged such that back sides of the first centrifugal impeller and the second centrifugal impeller face to each other, wherein an upstream portion of the connection flow path is formed integrally with the first housing, and a downstream portion of the connection flow path is formed integrally with the second housing, wherein the first housing has a first scroll chamber surrounding the first centrifugal impeller and disposed so that compressed fluid from the first centrifugal impeller is introduced, and an outlet flow path open to the second housing side and communicating with an end portion of the first scroll chamber, wherein the second housing has an introduction flow path open to the first housing side, communicating with the outlet flow path and arranged such that compressed fluid from the first compression stage is introduced thereinto, wherein the first scroll chamber is formed by an inner scroll chamber surrounding the first centrifugal impeller and disposed so that compressed fluid from the first centrifugal impeller is introduced, and an outer scroll chamber positioned on an outer side in a radial direction than the inner scroll chamber and communicating with an outlet portion of the inner scroll chamber, wherein the connection flow path is formed by the outlet flow path, the introduction flow path, and the outer scroll chamber, wherein the inner scroll chamber has a cross sectional flow path area that gradually increases toward a downstream end of the inner scroll chamber, wherein the outer scroll chamber extends in a circumferential direction of the inner scroll chamber at least partially surrounding the inner scroll chamber and the outer scroll chamber has a cross sectional flow path area larger than that of the downstream end of the inner scroll chamber at a connection part between the inner scroll chamber and the outer scroll chamber, sufficient to lower speed of fluid in the outer scroll chamber, wherein the outer scroll chamber is configured so that fluid flows into the outlet flow path and then the introduction flow path that forms a curved portion of the connection flow path.