Non-contact seal assembly in gas turbine engine

A method for making a non-contact seal assembly to be used for sealing a gap between a stator and a rotor rotatable relative to the stator in a gas turbine engine comprising:

• providing a primary seal comprising a seal shoe, wherein the seal shoe comprises a plurality of seal shoe segments circumferentially spaced apart from each other, and wherein each seal shoe segment is configured to be movable in a radial direction;
• disposing a mid-plate forward to the primary seal;
• disposing an aft secondary seal forward to the mid-plate, wherein the aft secondary seal comprises a plurality of aft secondary seal segments circumferentially spaced apart from each other, and wherein each aft secondary seal segment is attached to a respective seal shoe segment of the plurality of seal shoe segments and is configured to be movable in the radial direction along with each seal shoe segment;
• disposing a forward secondary seal forward to the aft secondary seal;
• providing a seal carrier comprising an outer ring and a front plate and a back plate, wherein the front plate and the back plate extend circumferentially along the outer ring and radially from two axial sides of the outer ring forming a U-shape, and wherein the primary seal, the mid-plate, the aft secondary seal and the forward secondary seal are assembled in the U-shape;
• holding the primary seal, the mid-plate, and the forward secondary seal to the seal carrier between the front plate and the back plate by a pin;
• and
• providing at least a notch at an outer radial side of each aft secondary seal segment, wherein the notch is configured to receive the pin for accommodating a radial movement of the respective seal shoe segment of the plurality of seal shoe segments.

A gas turbine engine comprising:

• a stator;
• a rotor rotatable relative to the stator;
• and
• a non-contact seal assembly arranged between the stator and the rotor configured to seal a gap between the stator and the rotor,
• wherein the non-contact seal assembly comprises:
• a primary seal comprising a seal shoe, wherein the seal shoe comprises a plurality of seal shoe segments circumferentially spaced apart from each other, and wherein each seal shoe segment is configured to be movable in a radial direction;
• a mid-plate disposed forward to the primary seal;
• an aft secondary seal disposed forward to the mid-plate, wherein the aft secondary seal comprises a plurality of aft secondary seal segments circumferentially spaced apart from each other, and wherein each aft secondary seal segment is attached to a respective seal shoe segment of the plurality of seal shoe segments and is configured to be movable in the radial direction along with each seal shoe segment;
• a forward secondary seal disposed forward to the aft secondary seal;
• a seal carrier comprising an outer ring and a front plate and a back plate, wherein the front plate and the back plate extend circumferentially along the outer ring and radially from two axial sides of the outer ring forming a U-shape, and wherein the primary seal, the mid-plate, the aft secondary seal and the forward secondary seal are assembled in the U-shape;
• and
• a pin to hold the primary seal, the mid-plate, and the forward secondary seal to the seal carrier between the front plate and the back plate,
• wherein each aft secondary seal segment comprises at least a notch at an outer radial side, and wherein the notch is configured to receive the pin for accommodating a radial movement of the respective seal shoe segment of the plurality of seal shoe segments.