Patent ID: 9671139
Date: 2017-06-06
CPC Classifications: F04C,F04D,F16C,F24F,F25B,G05B,G05D

Claim:
1. A centrifugal compressor for compressing a refrigerant vapour in a refrigeration cycle, the compressor comprising: an impeller drive shaft supported by first and second radial bearings for rotation within the compressor housing; an impeller assembly including at least one centrifugal impeller wheel mounted on the impeller drive shaft to rotate with the impeller drive shaft; and a refrigerant vapour feed taken from two or more regions of the impeller wheel or wheels of the impeller assembly, including a relatively low pressure region and a relatively high pressure region; the compressor further comprises a valve arrangement for selectively connecting either the higher pressure region or the lower pressure region of the impeller wheels(s) to the conduit that supplies refrigerant vapour to the radial bearings; wherein the first and second radial bearings are hydrodynamic fluid bearings in which the bearing fluid is the refrigerant vapour, the compressor further comprising a conduit for supplying a portion of the refrigerant vapour from the impeller assembly to the first and second fluid bearings.