Rotor end band
An end band and method of forming an end band for a rotor. The end band includes a hollow cylindrical band, wherein at least a portion of the band has a grain flow in a direction parallel to the hoop stress of the band. The end band also includes at least a portion having a grain flow in a direction perpendicular to the hoop stress of the band.
1. A method for manufacturing an end band comprising:
forming a hollow cylinder having an open end and a closed end via a hydroforming process;
stress-relieving the hollow cylinder at a first temperature;
aging the hollow cylinder at a second temperature greater than the first temperature after stress-relieving the hollow cylinder; and
removing the closed end of the hollow cylinder after aging the hollow cylinder to form an end band.
2. The method for manufacturing an end band according to claim 1 , further comprising forming the hollow cylinder from a flat sheet of material.
3. The method for manufacturing an end band according to claim 1 , wherein a height of the hollow cylinder is the same as a width of the end band.
4. The method for manufacturing an end band according to claim 1 , wherein a height of the hollow cylinder is the same as a width of a plurality of end bands.
5. The method for manufacturing an end band according to claim 1 , wherein the closed end of the hollow cylinder is removed by machining.
6. The method for manufacturing an end band according to claim 1 , wherein the hollow cylinder is aged to reduce internal stresses in the band.
7. The method for manufacturing an end band according to claim 1 , wherein the hollow cylinder is stress-relieved to control the growth of the grain size.
8. The method for manufacturing an end band according to claim 1 , wherein at least one portion of the end band has a first grain flow in a direction along a circumference of the end band and at least one portion of the end band has a second grain flow in a direction parallel to a width of the end band.