Blade tip clearance systems

1. A rotating blade tip clearance system for a gas turbine engine, comprising:

a control ring carrier for retaining a control ring therein, the control ring carrier defining a centerline axis and having:

a connecting portion for connecting to a case;

a retaining portion radially inward of the connecting portion, wherein the retaining portion includes radially inner and outer diameter sides defining a retaining cavity therebetween for retaining a control ring therein; and

a flange connecting radially between the connecting portion and the retaining portion, wherein the flange isolates the retaining portion of the control ring carrier from a thermal deflection of a case and assists in keeping the control ring carrier aligned about centerline axis A during thermal deflection;

a control ring within the retaining cavity of the control ring carrier, wherein the control ring has a different thermal response rate from the control ring carrier so that the control ring thermally deflects slower than the control ring carrier, thereby controlling a rate and/or an extent of thermal deflection of the control ring carrier; and

a cover engaged with the inner and outer diameter sides of the retaining portion of the control ring carrier and the control ring to cover the retaining cavity of the control ring carrier, wherein the cover includes protrusions extending axially outward from an aft facing surface of the cover for engaging with recessed pockets of the control ring.

2. A rotating blade tip clearance system as recited in claim 1 , wherein the cover includes circumferentially spaced hooks on an inner diameter side of the cover for engaging with the inner diameter side of the retaining portion of the control ring carrier and a lip on an outer diameter side of the cover for engaging with the outer diameter side of the retaining portion of the control ring carrier.

3. A rotating blade tip clearance system as recited in claim 1 , further comprising an outer air seal engaged with the control ring carrier, wherein the control ring carrier thermally isolates the control ring from the outer air seal.

4. A rotating blade tip clearance system as recited in claim 1 , wherein the inner diameter side of the retaining portion of the control ring carrier includes hooks that extend radially inward to engage with an outer air seal.

5. A rotating blade tip clearance system as recited in claim 1 , wherein the connecting portion of the control ring carrier includes an annular hook that extends radially outward to engage with a case.

6. A rotating blade tip clearance system as recited in claim 1 , wherein the retaining portion of the control ring carrier includes recessed pockets defined in cavity facing surfaces of each of the inner and outer diameter sides of the retaining portion to thermally isolate the control ring from the control ring carrier.

7. A rotating blade tip clearance system as recited in claim 1 , further comprising connector segments between the control ring and the control ring carrier, wherein the control ring, the control ring carrier and the connector segments are each manufactured as a single unit by one of casting or direct metal laser sintering.

8. A rotating blade tip clearance system as recited in claim 1 , wherein the control ring includes multiple arcuate segments joined together to form the control ring, wherein joints between the multiple arcuate segments are each secured with a radially oriented pin.

9. A rotating blade tip clearance system as recited in claim 1 , wherein the control ring carrier includes multiple arcuate segments that join together to form the control ring carrier, joints between the multiple arcuate segments are each secured with a radially oriented pin.

10. A rotating blade tip clearance system for a gas turbine engine, comprising:

a control ring carrier for retaining a control ring therein, the control ring carrier defining a centerline axis and having:

a connecting portion for connecting to a case;

a retaining portion radially inward of the connecting portion, wherein the retaining portion includes radially inner and outer diameter sides defining a retaining cavity therebetween for retaining a control ring therein; and

a flange connecting radially between the connecting portion and the retaining portion, wherein the flange isolates the retaining portion of the control ring carrier from a thermal deflection of a case and assists in keeping the control ring carrier aligned about centerline axis A during thermal deflection;

a control ring within the retaining cavity of the control ring carrier, wherein the control ring has a different thermal response rate from the control ring carrier so that the control ring thermally deflects slower than the control ring carrier, thereby controlling a rate and/or an extent of thermal deflection of the control ring carrier; and

connector segments between the control ring and the control ring carrier, wherein the control ring, the control ring carrier and the connector segments are each manufactured as a single unit by one of casting or direct metal laser sintering; wherein the control ring, the control ring carrier and the connector segments are different materials.

11. A rotating blade tip clearance system comprising:

a control ring carrier for retaining a control ring therein, the control ring carrier defining a centerline axis having radially inner and outer diameter sides with a retaining cavity therebetween for retaining a control ring therein;

a control ring within the retaining cavity of the control ring carrier;

a splined carrier surrounding at least a portion of the control ring carrier, wherein the splined carrier includes circumferentially spaced apart splines for engaging corresponding axial protrusions extending in a forward direction from the control ring carrier, and wherein the control ring has a different thermal response rate from the splined carrier and the control ring carrier so that the control ring thermally deflects slower than the splined carrier and the control ring carrier, thereby controlling a rate and/or an extent of thermal deflection of the control ring carrier and the splined carrier; and

a cover engaged with the inner and outer diameter sides of the control ring carrier and the control ring to cover the retaining cavity of the control ring carrier, wherein the cover includes protrusions extending axially outward from an aft facing surface of the cover for engaging with recessed pockets of the control ring.

12. A rotating blade tip clearance system as recited in claim 11 , wherein the cover includes circumferentially spaced hooks on an inner diameter side of the cover for engaging with the inner diameter side of the control ring carrier and a lip on an outer diameter side of the cover for engaging with the outer diameter side of the control ring carrier.

13. A rotating blade tip clearance system as recited in claim 11 , further comprising an outer air seal engaged with the control ring carrier, wherein the control ring carrier thermally isolates the control ring from the outer air seal.

14. A rotating blade tip clearance system as recited in claim 11 , wherein the inner diameter side of the control ring carrier includes hooks that extend radially inward to engage with an outer air seal.

15. A rotating blade tip clearance system as recited in claim 11 , wherein an outer diameter side of the splined carrier includes an annular hook that extends radially outward to engage with a case.

16. A rotating blade tip clearance system as recited in claim 11 , wherein the control ring carrier includes recessed pockets defined in cavity facing surfaces of each of the inner and outer diameter sides to thermally isolate the control ring from the control ring carrier.