Gas turbine vane platform element
A gas turbine CMC shroud plate ( 48 A) with a vane-receiving opening ( 79 ) that matches a cross-section profile of a turbine vane airfoil ( 22 ). The shroud plate ( 48 A) has first and second curved circumferential sides ( 73 A, 74 A) that generally follow the curves of respective first and second curved sides ( 81, 82 ) of the vane-receiving opening. Walls ( 75 A, 76 A, 77 A, 78 A, 80, 88 ) extend perpendicularly from the shroud plate forming a cross-bracing structure for the shroud plate. A vane ( 22 ) may be attached to the shroud plate by pins ( 83 ) or by hoop-tension rings ( 106 ) that clamp tabs ( 103 ) of the shroud plate against bosses ( 105 ) of the vane. A circular array ( 20 ) of shroud plates ( 48 A) may be assembled to form a vane shroud ring in which adjacent shroud plates are separated by compressible ceramic seals ( 93 ).
1. A vane platform element for a gas turbine, comprising:
a CMC shroud plate comprising a radially inner surface, a radially outer surface, an upstream side, a downstream side, and first and second circumferential sides, relative to a central axis of the gas turbine, the sides defining a perimeter of the shroud plate;
a vane-receiving opening in the shroud plate, the vane-receiving opening corresponding to a cross section profile of a turbine vane airfoil, the vane-receiving opening comprising a convex curve adjacent to the first circumferential side of the shroud plate and a concave curve adjacent to the second circumferential side of the shroud plate; and
a CMC frame extending radially outward from the shroud plate, the CMC frame comprising an upstream wall along the upstream side of the shroud plate, a downstream wall along the downstream side of the shroud plate, and a cross-bracing wall structure that spans between the upstream and downstream walls;
wherein the first circumferential side of the shroud plate generally follows the convex curve of the vane-receiving opening, and the second circumferential side of the shroud plate generally follows the concave curve of the vane-receiving opening;
wherein the CMC frame extends continuously around the perimeter of the shroud plate, the cross-bracing structure comprising first and second circumferential walls along the respective first and second circumferential sides of the shroud plate;
a socket wall extending radially outward from the shroud plate around the vane-receiving opening; and
a pin channel having an access portion passing through at least one of the circumferential walls of the frame, and comprising further portions passing through two sides of the socket wall, all portions of the in channel being substantially mutually aligned.
2. A circular array of adjacent vane platform elements according to claim 1 , wherein each pair of adjacent platform elements is separated by a compressible ceramic seal.
3. A vane platform element for a gas turbine, comprising:
a turbine shroud plate comprising a socket that receives an end of a turbine vane airfoil, the socket comprising a vane-receiving opening in the shroud plate, the vane-receiving opening comprising a first side matching a pressure side of the airfoil, and a second side matching a suction side of the airfoil;
the shroud plate comprising a concave circumferential side adjacent to, and generally following the shape of, the first side of the vane-receiving opening, and a convex circumferential side adjacent to, and generally following the shape of, the second side of the vane-receiving opening; and
a continuous frame extending radially outward from a perimeter of the shroud plate relative to a central axis of the gas turbine, wherein the frame is formed of side walls around the perimeter of the shroud plate, including first and second circumferential walls following the first and second circumferential sides of the shroud plate;
wherein the socket further comprises an outwardly extending socket wall around the vane-receiving opening, the outwardly extending socket wall comprising a fastening mechanism for attaching the vane airfoil to the turbine shroud plate; and
the fastening mechanism comprising a in channel having an access portion passing through one of the circumferential walls of the frame, and comprising further portions passing through two sides of the socket wall, all portions of the in channel being substantially mutually aligned.
4. A vane platform element according to claim 3 , comprising:
multiple vane-receiving openings in the shroud plate between the first and second circumferential sides of the shroud plate;
a socket wall extending radially outward from the shroud plate around each vane-receiving opening;
the further portions of the pin channel passing through two sides of each of the socket walls, all portions of the pin channel being substantially mutually aligned following a circular arc of a gas turbine shroud ring.
5. A circular array of adjacent vane platform elements according to claim 3 , wherein each pair of adjacent platform elements is separated by a compressible ceramic seal.
6. A vane platform element for a gas turbine, comprising:
a CMC shroud plate comprising a radially inner surface, a radially outer surface, an upstream side, a downstream side, and first and second circumferential sides, relative to a central axis of the gas turbine, the sides defining a perimeter of the shroud plate;
a vane-receiving opening in the shroud plate, the vane-receiving opening corresponding to a cross section profile of a turbine vane airfoil, the vane-receiving opening comprising a convex curve adjacent to the first circumferential side of the shroud plate and a concave curve adjacent to the second circumferential side of the shroud plate; and
a CMC frame extending radially outward from the shroud plate, the CMC frame comprising an upstream wall along the upstream side of the shroud plate, a downstream wall along the downstream side of the shroud plate, and a cross-bracing wall structure that spans between the upstream and downstream walls;
wherein the first circumferential side of the shroud plate generally follows the convex curve of the vane-receiving opening, and the second circumferential side of the shroud plate generally follows the concave curve of the vane-receiving opening;
wherein the CMC frame extends continuously around the perimeter of the shroud plate, the cross-bracing structure comprising first and second circumferential walls along the respective first and second circumferential sides of the shroud plate;
multiple vane-receiving openings in the shroud plate between the first and second circumferential sides of the shroud plate;
a socket wall extending radially outward from the shroud plate around each vane-receiving opening; and
a pin channel comprising an access portion passing through at least one of the circumferential walls of the frame, and comprising further portions passing through two sides of each of the socket walls, all portions of the pin channel being substantially mutually aligned following a circular arc of a shroud ring of the gas turbine.