Centrifugal compressor with controlled tolerance stack and methods of assembling the same

A method of assembling a compressor that includes a compressor housing, the compressor housing having a datum, the method comprising:

• positioning a motor and a rotatable shaft in the compressor housing;
• positioning a bearing housing in the compressor housing, the bearing housing defining a center bore that receives the shaft, wherein positioning the bearing housing comprises abutting the datum with the bearing housing and aligning the compressor housing with the bearing housing using a first fit band;
• and
• positioning a volute assembly in the compressor housing adjacent to the bearing housing, the volute assembly comprising a diffuser plate, a volute plate defining a back axial surface of the volute assembly facing the bearing housing, one or more stops protruding from the back axial surface, and a second fit band, wherein positioning the volute assembly comprises:
• positioning the volute plate in the compressor housing adjacent the bearing housing;
• abutting the datum with the one or more stops and aligning the compressor housing with the volute assembly using the second fit band, wherein abutting the datum with the bearing housing and the one or more stops limits axial tolerance stack between the bearing housing and the volute assembly;
• securing the volute plate to the datum via holes extending through the one or more stops that abut the datum;
• and
• positioning the diffuser plate in the compressor housing adjacent the volute plate to form the volute assembly;
• wherein the first fit band and the second fit band limit axial tolerance stack to a centerline of the compressor housing.