Finned structural disk spacer arm

A rotor assembly for use in a gas turbine engine comprising:

• a) a plurality of rotor disks, each disk supported in a cavity for rotation about an engine axis;
• b) a circumferentially continuous disk spacer arm extending axially from one of the disks and adapted to transmit loads between adjacent disks;
• and
• c) a plurality of cooling fins extending from the spacer arm into the cavity, wherein said plurality of cooling fins are deployed in equal number about a midpoint of a body section of said arm;
• d) wherein said plurality of cooling fins are positioned on the spacer arm to reduce bending stresses in the arm caused by thermal distortion of the spacer arm, wherein a distance from said midpoint of said body section of said spacer arm to any one of said fins is less than one half of a second distance from said midpoint to an end of said spacer arm.

A rotor assembly for use in a gas turbine engine comprising:

• a) a plurality of rotor disks, each disk supported in a cavity for rotation about an engine axis;
• b) a circumferentially continuous disk spacer arm extending axially from one of the disks and adapted to transmit loads between adjacent disks;
• c) wherein the disk spacer arm is adapted for transmitting axial loads and bending moments between adjacent rotor disks in a gas turbine engine, the spacer arm including:
• i) a spacer arm first end rigidly fixed to an adjacent rotor disk;
• ii) a spacer arm second end axially spaced from the first end;
• iii) a spacer arm body section extending intermediate the spacer arm first and second ends to separate a radially outward, relatively high temperature gas flow from a radially inward, relatively lower temperature cavity;
• iv) a plurality of spacer arm cooling fins extending from the spacer arm body section into the lower temperature cavity;
• and
• d) wherein said plurality of spacer arm cooling fins are centered about the midpoint of the spacer arm body section.

A rotor assembly for use in a gas turbine engine comprising:

• a) a plurality of rotor disks, each rotor disk including a plurality of blades extending into a high temperature gas flow;
• b) a structural disk spacer arm adapted for transmitting loads between adjacent rotor disks, the spacer arm having a first surface bounding a relatively higher temperature cavity in fluid communication with the high temperature gas flow, and the spacer arm having a second surface bounding a relatively lower temperature cavity;
• c) means for directing cooling air into the relatively higher temperature cavity;
• and
• d) a plurality of cooling fins extending from the disk spacer arm into the relatively lower temperature cavity, wherein the cooling fins are centered about the midpoint of a spacer arm body section.