Patent ID: 8201621
Filing Date: 2012-06-19
Classification: F01D,F05D,F28F,Y02T

Abstract:
1. A hollow passage in a machine element for enhancing the heat exchanging properties between the machine element and a fluid flowing through the hollow passage; the hollow passage comprising a helicoidal groove; wherein the helicoidal groove includes an approximately constant pitch, wherein an approximately constant pitch means the helicoidal groove comprises a substantially uniform helicoidal pattern that repeats at substantially regular axial distances as the helicoidal groove extends around the hollow passage; wherein the hollow passage comprises a circular cross-section; wherein the ratio of the pitch of the helicoidal groove to the diameter of the circular cross-section is between approximately 0.1 and 10.0; and wherein the helicoidal groove comprises one of an approximate semicircular profile and an approximate rectangular profile.