Seal structure

A porous abradable seal structure adapted to provide one element of a two element fluid-cooled seal with relative movement between the two elements, the structure having a contact surface adapted to cooperate with the other element of the seal and having a rear surface, the seal structure comprising a plural number of strips, each strip having two faces and having two edges, the strips being stacked face-to-face and bonded together, with the lengthwise direction of the seal strips extending generally in the direction of relative movement of the seal elements;

• the strips being so disposed that the faces of the strips extend from the said contact surface to the said rear surface of the seal structure and that the edges of the stacked strips define the said contact surface and the said rear surfave, and a large proportion of the strips having grooves in and extending completely across at least one face of the strip between the opposite edges thereof to define with an abutting strip pores for flow of a fluid through the seal structure from the rear surface to the contact surface, the grooves being of greater cross-sectional area adjacent the contact surface than adjacent the rear surface so that the portion of the seal structure adjacent the contact surface is more readily abradable than the portion adjacent the rear surface and the portion adjacent the rear surface is effective to meter flow of the fluid.

A porous abradable seal structure adapted to provide one element of a two element fluid-cooled seal with realtive movement between the two elements, the structure having a contact surface adapted to cooperate with the other element of the seal and having a rear surface, the seal structure comprising a plural number of strips, each strip having two faces and having two edges, the strips being stacked face-to-face and bonded together, with the lengthwise direction of the seal strips extending generally in the direction of relative movement of the seal elements;

• the strips being so disposed that the faces of the strips extend from the said contact surface to said rear surface of the seal structure and that the edges of the stacked strips define the said contact surface and the said rear surface;
• a large proportion of the strips having grooves in and extending completely across at least one face of the strip between the opposite edges thereof to define with an abutting strip pores for flow of a fluid through the seal structure from the rear surface to the contact surface, the pores being at an acute angle to the contact surface so as to discharge the fluid with a component of velocity in the direction of movement of the other seal element;
• and the grooves being of greater cross-sectional area adjacent the contact surface than adjacent the rear surface so that the portion of the seal structure adjacent the contact surface is more readily abradable than the portion adjacent the rear surface and the portion adjacent the rear surface is effective to meter flow of the fluid.