Annular casing for a turbine engine compressor
View Patent ↗A metal annular casing ( 16 ) for a turbine engine compressor, the casing having at least one annular row of radial chimneys for receiving outer cylindrical pivots of variable-pitch vanes, together with an outer cylindrical centering track ( 28 ) that is continuous or interrupted and against which runners carried by an annular ring for controlling the pitch of the vanes are to come to bear, the casing being characterized in that the track is formed by blocks ( 30 ) of plastics material fitted onto the casing and that are fastened or held on the casing.
1. A metal annular casing for a turbine engine compressor, the casing comprising:
at least one annular row of radial chimneys for receiving outer cylindrical pivots of variable-pitch vanes; and
an outer cylindrical centering track that is continuous or interrupted and against which runners carried by an annular ring for controlling the pitch of the vanes are to come to bear,
wherein the track is formed by blocks of plastics material fitted onto the casing,
wherein the casing includes means for retaining the blocks axially, the retaining means comprising two annular walls that are formed integrally with the casing and that extend radially outwards, the walls being upstream and downstream relative to the blocks, and
wherein an axial distance between the walls is substantially equal to an axial length of the blocks.
2. The casing according to claim 1 , wherein the blocks are fastened on the casing by adhesive.
3. The casing according to claim 1 , wherein at least one of the walls has a section that is L-shaped and includes at an outer periphery thereof a cylindrical rim for retaining the blocks radially.
4. The casing according to claim 1 , wherein each block includes means co-operating by connecting shapes with complementary means of the walls to prevent the block from turning relative to the casing.
5. A metal annular casing for a turbine engine compressor, the casing comprising:
at least one annular row of radial chimneys for receiving outer cylindrical pivots of variable-pitch vanes; and
an outer cylindrical centering track that is continuous or interrupted and against which runners carried by an annular ring for controlling the pitch of the vanes are to come to bear,
wherein the track is formed by blocks of plastics material fitted onto the casing,
wherein the casing includes means for retaining the blocks axially, the retaining means comprising at least one annular wall that is formed integrally with the casing, extends radially outwards, and is upstream or downstream relative to the blocks, and
wherein each block includes a tongue at one of a circumferential end thereof for engaging in a recess of complementary shape at the facing circumferential end of an adjacent block.
6. A metal annular casing for a turbine engine compressor, the casing comprising:
at least one annular row of radial chimneys for receiving outer cylindrical pivots of variable-pitch vanes; and
an outer cylindrical centering track that is continuous or interrupted and against which runners carried by an annular ring for controlling the pitch of the vanes are to come to bear,
wherein the track is formed by blocks of plastics material fitted onto the casing,
wherein the casing includes means for retaining the blocks axially, the retaining means comprising at least one annular wall that is formed integrally with the casing, extends radially outwards, and is upstream or downstream relative to the blocks, and
wherein the blocks include orifices at circumferential ends thereof for passing safety wires, each safety wire serving to pass through the orifices of the facing circumferential ends of two adjacent blocks.
7. A metal annular casing for a turbine engine compressor, the casing comprising:
at least one annular row of radial chimneys for receiving outer cylindrical pivots of variable-pitch vanes; and
an outer cylindrical centering track that is continuous or interrupted and against which runners carried by an annular ring for controlling the pitch of the vanes are to come to bear,
wherein the track is formed by blocks of plastics material fitted onto the casing,
wherein the casing includes means for retaining the blocks axially, the retaining means comprising at least one annular wall that is formed integrally with the casing, extends radially outwards, and is upstream or downstream relative to the blocks, and
wherein the blocks include at least one annular groove that is open in a radially outward direction and in which an annular cable is housed for holding the blocks and clamping the blocks radially against the casing.
8. The casing according to claim 1 , wherein the blocks are made of an engineering plastic.
9. A turbine engine, which includes a casing according to claim 1 .