摘要 |
A method of manufacturing a rotor (70) for use in an air motor. A shaft (10) is machined to have bearing surfaces (16 and 18) and adjacent ends (12 and 14), respectively. A working surface (20) with helix grooves (22, 24 and 26) is machined into the shaft (10). A locking surface (34) is machined into the shaft between the working surface (20) and end (14). A ring (36) is machined with helix grooves (38, 40 and 42) on its periphery and an inner diameter (44). The inner diameter has a diameter less than the locking surface (34) but greater than the bearing surface (18). The ring (36) is placed on bearing surface (18) of shaft (10). The shaft (10) with ring (36) on bearing surface (18) is placed in a fixture (50) and a tension force is applied to ends (12) and 14 ). The tension force causes the shaft (10) to axially expand and radially contract. When the diameter of the locking surface (34) is approximately equal to the diameter (44) of the ring (36), the ring (36) is pushed into contact with the working surface (20). After the helix grooves (22, 24, 26) are aligned with helix grooves (38, 40 and 42), the tension force is released allowing the locking surface to expand and frictionally hold the shaft (10) and ring (36) together such that a herringbone pattern is formed for rotor (70). |