Patent ID: 8496533

Claim:
A shaft for use in an air supply machine comprising: said shaft being hollow with an inner bore and an outer periphery, and a plurality of connection holes formed in said shaft, to provide cooling air from said outer periphery to said inner bore, and said plurality of connection holes for passing air along said inner bore of said shaft: a ratio of a diameter of said connection holes to an outer diameter of said outer periphery of said shaft is between .077 and .094: there are six of said connection holes, and said connection holes spaced to be formed at a distance from an end of a journal bearing that is to be associated with said outer periphery, and said distance being less than said outer diameter of said outer periphery of said shaft; and said shaft has a first outer peripheral portion to receive the journal bearing at said outer periphery, and a ditch having a smaller diameter, and said plurality of connection holes being formed in said ditch.