BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of an example turbine engine of the present invention;
FIG. 2 illustrates a portion of a cross-section of a typical compressor for the example turbine engine of the present invention;
FIG. 3 is an enlarged view of region 3-3 from FIG. 2, illustrating a portion of example disks which are axially adjacent to one another.
FIG. 4 is a perspective view of a portion of an example knife edge seal segment with an integral spacer bridge and the lock assemblies of the present invention during assembly;
FIG. 5 is a perspective view of the lock assembly of the present invention;
FIG. 6 is a perspective view of a portion of the example knife edge seal segment with the spacer bridge and lock assemblies of the present invention inserted on the compressor disks;
FIG. 7 is a perspective view of a portion of the example knife edge seal segment with the spacer bridge and lock assemblies of the present invention once assembled;
FIG. 8 is a cross-section of axially adjacent example disks where the lock assembly of FIG. 5 is in a lock position;
FIG. 9 is a portion of a cross-section for a second example compressor of the present invention; and
FIG. 10 is an enlarged cross-section of axially adjacent disks of the second example.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a schematic view of a turbine engine 10. Air is pulled into the turbine engine 10 by a fan 12 and flows through a low pressure compressor 14 and a high pressure compressor 16. Fuel is mixed with the air and combustion occurs within the combustor 18. Exhaust from combustion flows through a high pressure turbine 20 and a low pressure turbine 22 prior to leaving the engine through the exhaust nozzle 24.
FIG. 2 illustrates a portion of a cross-section of a typical compressor including multiple disks 26 defining a compressor rotor. Each disk 26 rotates about an axis A located along the centerline of the turbine engine 10. A plurality of rotor blades 28 are mounted about the circumference of each of the disks 26. A plurality of stator vanes 30 extend between the rotor blades 28 of axially adjacent disks 26, as shown.
Each disk 26 includes a disk rim 32. The disk rim 32 supports the rotor blades 28. A backbone 34 extends from each disk rim 32. A plurality of knife edge seal segments 36 are supported by the backbone 34. The knife edge seal segments 36 are preferably formed of the same material as the disk 26 such as any ferrous, nickel, or ceramic materials. For example, a lightweight material such as Titanium. The knife edge seal segments 36 are each in close proximity to the stator vanes 30, as shown, to restrict leakage of the compressed air from between the stator vane and the compressor rotor to limit the recirculation of air within the compressor. In fact the knife edge seal segments 36 contact an abradable honeycomb material 31 associated with the stator vanes 30. Retaining flanges 38a and 38b (FIG. 3) extend from each disk rim 32 to retain the knife edge seal segments 36 to the backbones 34.
FIG. 3 illustrates portions of example disks 26a and 26b which are axially adjacent to one another. A backbone 34a on the disk 26a is in contact with a backbone 34b of the axially adjacent disk 26b. The backbone 34a is preferably welded to the backbone 34b, illustrated by weld bead 60. However, the backbone 34a and the backbone 34b can also be bolted together or secured in another know manner. A retaining flange 38a extends from the disk 26a and a retaining flange 38b extends from the disk 26b. A plurality of knife edge seal segments 36a are arranged about the circumference of the backbone 34a and a plurality of knife edge seal segments 36b are arranged about the circumference of the backbone 34b. Each knife edge seal segment 36a and 36b is supported by the corresponding backbones 34a and 34b and retained by the corresponding retaining flange 38a and 38b. The backbone 34a and 34b may be of unequal lengths and one of the backbone 34a may also support a portion of the knife edge seal segment 36b of the axially adjacent disk 26b.
Referring to FIGS. 4 through 8 assembly of the knife edge seal segments 36 onto the disks 26 is explained. The knife edge seal segment 36a is inserted past the retaining flange 38a such that a body portion 40a of the knife edge seal segment 36a contacts the backbone 34a. The knife edge seal segment 36b is then inserted past the retaining flange 38b in a similar manner. A knife edge runner 42a protrudes radially outward from the body portion 40a and proximate the stator vane 30. Likewise, a body portion 40b of the knife edge seal segment 36b contacts the backbone 34b and a knife edge runner 42b protrudes from the body portion 40b, proximate the stator vane 30. The knife edge runners 42a and 42b contact different portions of the same stator vane 30. Preferably, there are multiple knife edge runners 42 contacting each stator vane 30. Each knife edge seal segment 36 may have multiple knife edge runners 42 protruding form the body portion 40.
Once assembled, each knife edge seal segment 36 mates with a circumferentially adjacent knife edge seal segment 36 to provide a rigid structure. Stress placed on disk 26 during compressor operation does not transfer to the knife edge seal segment 36 because the knife edge seal segments 36 are separate elements from the disks 26 and segmented. The arrangement also allows for replacement of individual knife edge seals segments 36 without requiring an entire new disk 26.
Each of the knife edge seal segments 36a and 36b have an integral spacer bridge 44a extending from the body portion 40a and 40b, as illustrated in FIG. 4. In order to assemble the knife edge seal segments 36a and 36b the spacer bridges 44a and 44b are staggered from one another as they are assembled, as shown in FIG. 6. The staggered arrangement of the integral spacer bridges 44a and 44b allows the knife edge seal segment 36b to be inserted past the retaining flange 38b when the knife edge seal segment 36a is already assembled. A lock assembly 46, shown in FIG. 5, is inserted between the knife edge seal segments 36a and 36b after each staggered spacer bridges 44a and 44b.
The lock assemblies 46 each include a lock housing 48 and a set screw 50. The lock assembly 46 is assembled by inserting the lock housing 48 past the retaining flanges 38a and 38b such that the bottom of the lock housing 48 is in contact with the disk backbones 34a and 34b. The lock assembly 46 is then rotated 90-degrees about a lock axis. That is, the lock assemblies 46 are initially inserted in an orientation as shown at 100 in FIG. 6, then rotated to the orientations 102, or that shown between knife edge seal segments 36a and 36b in FIG. 6.
When rotating the lock assembly 46 a portion of the lock housing 48 is placed under the knife edge seal segments 36a and 36b to prevent the lock housing 48 from upward movement. Once rotated the lock housing 48 interferes with the knife edge seal segments 36a and 36b and is prevented from movement past the retaining flanges 38a and 38b. The lock housing 48 has pressure faces 52 to provide a surface for contacting the knife edge seal segments 36a and 36b. During assembly of the knife edge seal segments 36 the lock assemblies 46 remain in a retracted position.
The process of inserting the knife edge seals segments 36 with the spacer bridges 44 and the lock assemblies 46 is repeated until all the knife edge seal segments 36 and lock assemblies 46 have been assembled onto the disks 26. The knife edge seal segments 36a and 36b with the spacer bridges 44a and 44b are in a staggered arrangement as described above in order to provide space for assembly. When all the knife edge seals segments 36 have been inserted the axial movement along the axis A of the turbine engine 10 is no longer necessary. Therefore, once inserted, the knife edge seal segments 36a with spacer bridges 44a are moved about the circumference of the disk 26a, shown in phantom in FIG. 6. The adjacent knife edge seal segments 36b with spacer bridges 44b remain stationary. FIG. 7 illustrates another example of the lock assemblies 46 and knife edge seal segments 36a and 36b with the spacer bridges 44a and 44b once rotated. The spacer bridges 44a are moved to locate the spacer bridge 44a and spacer bridges 44b across from one another, i.e. they are no longer staggered. The spacer bridges 44a and 44b contact each other and prevent axial movement of the knife edge seal segments 36a and 36b along the axis A of the turbine engine 10. A single spacer bridge 44a and spacer bridge 44b can be located between each of the lock assemblies 46. Alternatively, multiple spacer bridges 44a and 44b can be located between each of the lock assemblies 46.
In one example, there are eight lock assemblies 46. The number of lock assemblies 46 and the number and length of the knife edge seal segments 36 may vary. One skilled in the art would be able to determine the appropriate numbers and lengths of knife edge seal segments 36 and lock assemblies 46.
Referring now to FIG. 8, once assembled and rotated into position, the knife edge seal segments 36 and lock assemblies 46 must be prevented from shifting and rotating circumferentially. Thus, the lock assemblies 46 are moved from the retracted position to the extended position. The set screw 50 on each lock assembly 46 is tightened, thus moving the lock assembly 46 into the extended or “locked” position. The lock assemblies 46 each include a first interlocking feature 56 and the backbone 34a includes a second interlocking feature 58. When the lock assemblies 46 are in the lock position the first interlocking feature 56 and the second interlocking feature 58 interact together to prevent circumferential movement of the lock assemblies 46. In the example shown, the first interlocking feature 56 is a rounded end of set screw 50 and the second interlocking feature 58 is a depression in the backbone 34a. The second interlocking feature 58 may be a continuous depression or a plurality of depressions spaced around the circumference of the backbone 34a at desired location. Of course, the second interlocking feature 58 may be formed in the second backbone 34b, or partially formed in both the first and second backbone 34a and 34b.
FIGS. 9 and 10 are a second example of a turbine engine utilizing knife edge seal segments 102 of the present invention within a compressor 104. FIG. 9 illustrates a portion of a cross-section of a typical compressor 104 including multiple disks 106 defining a compressor rotor. Each disk 26 rotates about an axis located along a centerline 108 of the turbine engine.
In the second example the disks 106a and 106b are bolted together at the centerline 108 of the engine. The bolts are not shown. Compressor disks 106 are typically bolted together at the rear of the compressor 104. Disk 106b is illustrated as a rear shaft of the rotor. However, the second example may be utilized for any consecutive disks 106 within the compressor 104 that are bolted together.
Referring to FIG. 10, the disk 106b includes a disk backbone 110b extending from a rim 112b of the disk 106b. A knife edge seal segment 102 is placed on the disk backbone 110b. A body portion 116 of the knife edge seal segment 102 is in contact with the disk rim 112b and a knife edge 118 extends away from the body portion 116, as illustrated. Each knife edge seal segment 102 may have a plurality of knife edges 118 extending away from the body portion 116.
A pin 120 is inserted through a segment hole 122 in the knife edge seal segment 102 to retain the knife edge seal segment 102 to the disk 106b. Each knife edge seal segment 102 may have a plurality of segments holes 122. A pin 120 is inserted into each of the segment holes 122 and into a corresponding rim slot 123. Additional knife edge seal segments 102 and pins 120 are inserted until the circumference of the disk backbone 110b has been filled. Once assembled the disk 106b is positioned within the compressor 104 and bolted to disk 106a. Rim 112a of disk 106a is in contact with the knife edge seal segments 102 assembled to disk 106b. The rim 112a may overlap the backbone 110b to limit the recirculation of air. Pins 120 prevent the knife edge seal segments 102 from rotating circumferentially about the disk 106b.
Alternately the knife edge seal segments 102 may be inserted between the rim 112a and the rim 112b after the disk 106b has been assembled within the compressor 104. In this instance the knife edge seal segments 102 would not require segment holes 122 or pins 120. Instead, a lock assembly 46 (illustrated in FIG. 5) would be inserted between each circumferentially adjacent knife edge seal segments 102. The disk rims 112a and 112b would be formed to have a retaining flange, as described in the above embodiment, to retain the lock assembly 124, and the backbone 110b would include an interlocking feature to correspond with interlocking feature 128 on the lock assembly 124. The body portion 116 may be shaped to fit with the retaining flange 126 and still allow the knife edge seal segments 102 to be inserted between the disk rims 112a and 112b.
Although the example embodiment discloses an arrangement of assembling knife edge seal segments onto a rotor disk for a compressor the arrangement may be used for any rotor and seal assembly.
Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.
Patent Application
20070297897
