LOCKING SPACER ASSEMBLY BETWEEN COMPRESSOR BLADE STRUCTURES IN A TURBINE ENGINE TECHNICAL FIELD

This invention relates generally to turbine engines, and, more particularly, to a locking spacer assembly for a slot between adjacent compressor blade structures.

BACKGROUND ART

A conventional gas turbine engine includes a compressor section, a combustion section, and a turbine section. Ambient air is compressed in the compressor section, which air is supplied to the combustion section where the compressed air is combined with a fuel and ignited to create combustion products defining a hot working gas. The working gas is supplied to the turbine section where the gas passes through a plurality of stages of stationary vanes and rotating blades. The rotating blades are coupled to a rotor, which forms a part of a rotating shaft. As the working gas expands through the turbine, the working gas causes the blades, and therefore the rotor and shaft, to rotate. The shaft also causes rotation of rows of rotating compressor blades in the compressor section.

SUMMARY OF INVENTION

In accordance with a first aspect of the invention, a blade disc assembly is provided in a turbine engine that includes a rotatable shaft extending in an axial direction of the engine. The blade disc assembly comprises a plurality of rotatable blade structures spaced apart from one another in a circumferential direction, each blade structure including at least one airfoil and a root. A circumferential first gap having a direction of elongation in a first direction transverse to the circumferential direction is defined between adjacent blade structures, the first gap being defined by opposing first and second side edges of the corresponding adjacent blade structures. The blade disc assembly further comprises a locking spacer assembly provided in at least one of the first gaps between adjacent blade structures. The locking spacer assembly comprises opposed first and second side edge members provided in the first gap adjacent to the first and second side edges of the adjacent blade structures. Each side edge member is associated with the blade structures such that radial movement therebetween is substantially prevented. Each side each member includes a recessed portion along a top surface thereof and defines a groove along an inner edge removed from the top surface thereof. The first and second side edge members are spaced apart from one another in the first direction such that a second gap having a reduced dimension in the first direction, as compared to the first gap, is defined therebetween within the first gap. The locking spacer assembly further comprises opposed first and second end members provided in the second gap. The first and second end members each include opposed tongue members that are received within the respective grooves of the first and second side edge members to substantially prevent radial movement of the first and second end members relative to the first and second side edge members. The end members further include a projection extending in the circumferential direction from an edge toward the opposed end member. The first and second end members are spaced apart from one another in the circumferential direction such that a third gap having a reduced dimension in the circumferential direction, as compared to the second gap, is defined therebetween within the second gap. The locking spacer assembly additionally comprises a cap member received by the recessed portions of the respective first and second side edge members so as to cover the third gap. The cap member includes opposed first and second notches. Rotation of the cap member while positioned within the recessed portions of the respective first and second side edge members causes the first and second notches to receive a respective one of the projections of the first and second end members to

substantially prevent radial movement of the cap member relative to the first and second end members.

The blade disc assembly may be provided in a compressor section of the engine.

The first and second side edge members may include respective radially outwardly facing surfaces that directly engage radially inwardly faces surfaces of a retainer structure to substantially prevent radial movement therebetween while allowing sliding movement therebetween in the circumferential direction.

The recessed portions of the first and second side edge members may be aligned in the circumferential direction and may cooperate to define an opening that receives the cap member. Opposed edge portions of the cap member may be secured to the first and second side edge members, e.g., by peening, once the projections of the first and second end members are received in the respective notches of the cap member to prevent further rotation of the cap member within the opening.

The first and second end members may be suspended in the second gap by the first and second side edge members such that respective radial spaces are defined between inner ends of the first and second end members and inner ends of the first and second side edge members.

In accordance with a second aspect of the invention, a locking spacer assembly is provided for a circumferential first gap between circumferentially adjacent blade structures in a turbine engine, the first gap having a direction of elongation in a first direction transverse to the circumferential direction. The locking spacer assembly comprises opposed first and second side edge members, each side edge member including a recessed portion along a top surface thereof and defining a groove along an inner edge removed from the top surface thereof. The first and second side edge members are spaced apart from one another in the first direction such that a second gap having a reduced dimension in the first direction, as compared to the first gap, is defined therebetween within the first gap. The locking spacer assembly further comprises opposed first and second end members provided in the second gap, the first and second end members each including opposed tongue members that are received within the respective grooves of the first and second side edge members to substantially prevent radial movement of the first and second end members relative to the first and second side edge members, and a projection extending in the circumferential direction from an edge toward the opposed end member. The first and second end members are spaced apart from one another in the circumferential direction such that a third gap having a reduced dimension in the circumferential direction, as compared to the second gap, is defined therebetween within the second gap. The locking spacer assembly additionally comprises a cap member received by the recessed portions of the respective first and second side edge members so as to cover the third gap, the cap member including opposed first and second notches. Rotation of the cap member while positioned within the recessed portions of the respective first and second side edge members causes the first and second notches to receive a respective one of the projections of the first and second end members to substantially prevent radial movement of the cap member relative to the first and second end members.

The first and second side edge members may include respective radially outwardly facing surfaces that directly engage radially inwardly faces surfaces of a retainer structure to substantially prevent radial movement therebetween while allowing sliding movement therebetween in the circumferential direction.

The recessed portions of the first and second side edge members may be aligned in the circumferential direction and may cooperate to define an opening that receives the cap member. Opposed edge portions of the cap member may be secured to the first and second side edge members, e.g., by peening, once the projections of the first and second end members are received in the respective notches of the cap member to prevent further rotation of the cap member within the opening.

The first and second end members may be suspended in the second gap by the first and second side edge members such that respective radial spaces are defined between inner ends of the first and second end members and inner ends of the first and second side edge members.

In accordance with a third aspect of the invention, a method is provided for installing a locking spacer assembly for use in a circumferential first gap between first and second circumferentially spaced apart rotatable blade structures in a turbine engine, the first gap having a direction of elongation in a first direction transverse to the circumferential direction and being defined by opposing first and second side edges of the respective blade structures. A first side edge member is inserted into the first gap adjacent to the first side edge of the first blade structure such that radial movement between the first side edge member and the first blade structure is substantially prevented. The first side edge member includes a recessed portion in a top surface thereof and defines a groove along an inner edge removed from the top surface thereof. A second side edge member is inserted into the first gap adjacent to the first side edge of the first blade structure such that radial movement between the second side edge member and the first blade structure is substantially prevented. The second side edge member includes a recessed portion in a top surface thereof and defines a groove along an inner edge removed from the top surface thereof. The first and second side edge members are spaced apart from one another in the first direction such that a second gap having a reduced dimension in the first direction, as compared to the first gap, is defined

therebetween within the first gap. A first end member is inserted into an opening defined by the respective recessed portions of the first and second side edge members. The first end member is moved in the circumferential direction such that opposed tongue members of the first end member are received within the respective grooves of the first and second side edge members to substantially prevent radial movement of the first end member relative to the first and second side edge members. A second end member is inserted into the opening, wherein the first and second end members each include a projection extending in the circumferential direction from an edge toward the opposed end member. The second end member is moved in the circumferential direction away from the first end member such that opposed tongue members of the second end member are received within the respective grooves of the first and second side edge members to substantially prevent radial movement of the second end member relative to the first and second side edge members. The first and second end members are spaced apart from one another in the circumferential direction such that a third gap having a reduced dimension in the circumferential direction, as compared to the second gap, is defined therebetween within the second gap. A cap member is inserted into the opening defined by the recessed portions of the first and second side edge members so as to cover the third gap. The cap member is rotated such that opposed first and second notches of the cap member receive the respective projections of the first and second end members to substantially prevent radial movement of the cap member relative to the first and second end members.

The first and second side edge members may include respective radially outwardly facing surfaces that directly engage radially inwardly faces surfaces of a retainer structure to substantially prevent radial movement therebetween while allowing sliding movement therebetween in the circumferential direction.

Opposed edge portions of the cap member may be secured to the first and second side edge members, e.g., by peening, once the cap member is rotated such that the projections of the first and second end members are received in the respective notches of the cap member to prevent further rotation of the cap member within the opening.

The first and second end members may be suspended in the second gap by the first and second side edge members such that respective radial spaces are defined between inner ends of the first and second end members and inner ends of the first and second side edge members.

Inserting the cap member may comprise seating the cap member on the recessed portions of the first and second side edge members.

The first and second side edge members may be radially inserted into the first gap between the circumferentially spaced apart first and second blade structures such that opposing side edges of the first and second side edge members engage the first and second side edges of the respective blade structures.

BRIEF DESCRIPTION OF DRAWINGS

While the specification concludes with claims particularly pointing out and distinctly claiming the present invention, it is believed that the present invention will be better understood from the following description in conjunction with the accompanying Drawing Figures, in which like reference numerals identify like elements, and wherein:

Fig. 1 is a schematic diagram of a turbine engine including at least one blade disc assembly according to an aspect of the present invention; Fig. 2 is a partial perspective view of the blade disc assembly schematically illustrated in Fig. 1 ;

Fig. 3 is a top plan view of a locking spacer assembly of the blade disc assembly illustrated in Fig. 2;

Fig. 4 is an exploded view of the locking spacer assembly illustrated in Fig. 3;

Fig. 5 is a cross-sectional view taken along line 5-5 from Fig. 3;

Fig. 6 is a cross-sectional view taken along line 6-6 from Fig. 3; and

Fig. 7 is a cross-sectional view taken along line 7-7 from Fig. 3. DESCRIPTION OF EMBODIMENTS

In the following detailed description of the preferred embodiment, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration, and not by way of limitation, a specific preferred embodiment in which the invention may be practiced. It is to be understood that other

embodiments may be utilized and that changes may be made without departing from the spirit and scope of the present invention.

Referring to Fig. 1 , a turbine engine 10 including one or more blade disc assemblies 12 according to an aspect of the invention is schematically illustrated. The engine 10 includes a compressor section 14, which includes at least one, and preferably a plurality, of the blade disc assemblies 12, a combustion section 16, a turbine section 18, and a conventional rotatable shaft 20 that defines an axial direction A _D of the engine 10.

Referring to Fig. 2, the blade disc assembly 12 includes an exemplary row of blade structures 22 spaced apart from one another in a circumferential direction C _D . The blade structures 22 in the exemplary embodiment shown each include a conventional root 24 and a single airfoil 26, although it is contemplated that the blade structures 12 could include more than one airfoil 26, e.g., two or three airfoils 26 adjacent to each other in the circumferential direction C _D and located on a common root 24. The root 24 is used to secure the blade structure 22 to a disc 28, which disc 28 forms a portion of the shaft 20 for supporting the corresponding airfoil 24 in a gas flow path F _P of the engine 10, wherein the blade structures 22 rotate with the shaft 20 during operation to drive the airfoils 26 circumferentially through the gas flow path F _P . As shown in Fig. 2, each airfoil 26 extends outwardly from a platform 32 of the corresponding blade structure 22 in a spanwise or radial direction R _D to a blade tip 34. As will be appreciated by one having ordinary skill in the art, the compressor section 14 may include a plurality of axially spaced blade assemblies 12, separated by corresponding rows of conventional stationary vane assemblies 36 (only one vane assembly 36 is illustrated for exemplary purposes in Fig. 1 ).

As shown in Fig. 2, circumferential first gaps 40 having a direction of elongation in a first direction F _D transverse to the circumferential direction C _D are defined between adjacent blade structures 22, wherein the phrase "direction of elongation" is meant to infer that the subject component is longer in the referenced direction than in any other direction. The first direction F _D may extend generally parallel to or slightly skewed with respect to the axial direction A _D as shown in Fig. 2, depending on the orientation and configuration of the blade disc assembly 12 and its blade structures 22. The first gaps 40 are defined by opposing first and second side edges 22A, 22B of the corresponding adjacent blade structures 22, see also Fig. 3.

Conventional spacer assemblies 42 are illustrated in Fig. 2 as being provided in a majority of the first gaps 40. However, according to an aspect of the present invention, the illustrated blade disc assembly 12 also includes a unique locking spacer assembly 44 in at least one of the first gaps 40 per row of blade structures 22. The blades structures 22, spacer assemblies 42, and locking spacer assembly(ies) 44 are axially and radially retained in place by a retainer structure comprising a disc structure 46, which disc structure 46 may form a part of the disc 28 and rotates with the shaft 20 during operation of the engine 10.

Referring now to Figs. 3-7, the locking spacer assembly 44 comprises opposed first and second side edge members 48, 50 provided in the first gap 40 adjacent to the first and second side edges 22A, 22B of the corresponding blade structures 22, see Fig. 3. The first and second side edge members 48, 50 are spaced apart from one another in the first direction F _D and are associated with the corresponding blade structures 22 such that axial and radial movement

therebetween is substantially prevented. Specifically, the side edge members 48, 50 and each of the blade structures 22 include respective radially outwardly facing surfaces 48A, 50A, 22C (see Fig. 2 for the surface 22C) that directly engage radially inwardly faces surfaces 46A, 46B of the disc structure 46 to substantially prevent radial movement therebetween, and between the side edge members 48, 50 and the blade structures 22, while allowing sliding movement between the blade structures 22 and side edge members 48, 50 and the disc structure 46 in the circumferential direction C _D .

Referring to Figs. 4 and 5, the side edge members 48, 50 each include a recessed portion 56, 58 along a top surface 60, 62 thereof. The recessed portions 56, 58 extend from the upper surface 60, 62 toward inner ends 64, 66 of the respective side edge members 48, 50. In one exemplary embodiment, the recessed portions 56, 58 may span about 1/3 of a height H of the side edge members 48, 50 (see Fig. 4), which height H is defined between the upper surface 60, 62 and the inner ends 64, 66 of the respective side edge members 48, 50, although the dimensions could vary without departing from the spirit and scope of the invention. The recessed portions 56, 58 may be arcuate-shaped when viewed from above (see Fig. 4) and may be aligned with one another in the circumferential direction CD such that the recessed portions 56, 58 cooperate to define an opening 70 in the top surfaces 60, 62 of the side edge members 48, 50, which opening 70 will be discussed in greater detail below.

With reference to Figs. 4 and 6, the side edge members 48, 50 each define a groove 74, 76 along an inner edge 78, 80 thereof. The grooves 74, 76 are removed from the top surfaces 60, 62 of the side edge members 48, 50 such that lips 82, 84 of the side edge members 48, 50 are provided over the grooves 74, 76 at the top surfaces 60, 62 of the respective side edge members 48, 50. The grooves 74, 76 extend from the recessed portions 56 , 58 (the grooves 74, 76 are in direct communication with the recessed portions 56, 58) of the side edge members 48, 50 to respective opposing side edges 86A, 86B and 88A, 88B thereof, see Fig. 4. As shown in Fig. 3, the first and second side edge members 48, 50 effectively reduce the dimension of the first gap 40 in the first direction F _D , such that the side edge members 48, 50 define a second gap 90 therebetween within the first gap 40, the second gap 90 having a reduced dimension in the first direction F _D as compared to the first gap 40. Stated alternately, the second gap 90 effectively reduces the dimension of the first gap 40 in the first direction F _D .

Referring now to Figs. 3, 4, and 6, the locking spacer assembly 44 further comprises opposed first and second end members 100, 102 provided in the second gap 90 and spaced apart from one another in the circumferential direction C _D . The first and second end members 100, 102 each include opposed tongue members 104, 106 and 108, 1 10 that are received within the respective grooves 74, 76 of the first and second side edge members 48, 50. As will be discussed below, the reception of the tongue members 104, 106 and 108, 1 10 within the grooves 74, 76 substantially prevents radial movement of the first and second end members 100, 102 relative to the first and second side edge members 48, 50.

The end members 100, 102 each further comprise a projection 1 14, 1 16 extending in the circumferential direction C _D from an edge 1 18, 120 of the respective end member 100, 102 toward the opposed end member 100, 102, see Fig. 4.

As shown in Fig. 3, the first and second end members 100, 102 effectively reduce the dimension of the second gap 90 in the circumferential direction C _D , such that the end members 100, 102 define a third gap 122 therebetween within the second gap 90, the third gap 122 having a reduced dimension in the circumferential direction C _D as compared to the second gap 90. Stated alternately, the third gap 122 effectively reduces the dimension of the second gap 90 in the circumferential direction C _D . With reference to Fig. 6, the first and second end members 100, 102 (only the first end member 100 is shown in Fig. 6), are suspended in the second gap 90 by the first and second side edge members 48, 50 such that respective radial spaces 124 are defined between inner ends 126, 128 of the first and second end members 100, 102 and the inner ends 64, 66 of the first and second side edge members 48, 50. Referring now to Figs. 3-5, the locking spacer assembly 44 additionally comprises a cap member 130 that is received by the recessed portions 56, 58 of the respective first and second side edge members 48, 50, i.e., within the opening 70 in the top surfaces 60, 62 of the side edge members 48, 50, so as to cover the third gap 122. The cap member 130 in the illustrated embodiment is generally circular in shape, i.e., disc-shaped, and includes opposed first and second notches 132, 134 formed by respective first and second foot members 136, 138 that extend laterally outwardly from a lower side 140 of the cap member 1 30. The notches 132, 134 each receive a respective one of the projections 1 14, 1 16 of the first and second end members 100, 102 to substantially prevent radial movement of the cap member 130 relative to the end members 100, 102, see Fig. 7.

A method of installing the locking spacer assembly 44 described above will now be described. With reference to Fig. 2, the conventional spacer assemblies 42 and blade structures 22 illustrated to the left and right of the locking spacer assembly 44 as shown in Fig. 2 will be assumed to have previously been installed in an annular slot A _s formed in the disc structure 46 by conventional methods.

The first and second side edge members 48, 50 of the locking spacer assembly 44 are inserted into the annular slot A _s and positioned in the first gap 40 defined between two circumferentially adjacent blade structures 22. This may be accomplished by inserting the first and second side edge members 48, 50 radially into the annular slot A _s , preferably one at a time, and then moving them oppositely in the first direction F _D such that the radially outwardly facing surfaces 48A, 50A, of the side edge members 48, 50 engage the respective radially inwardly faces surfaces 46A, 46B of the disc structure 46, see Fig. 5. At this point, the first and second side edge members 48, 50 are locked in place radially and axially by the disc structure 46 and are associated with the previously installed blade structures 22 such that radial movement therebetween is substantially prevented. Once the first and second side edge members 48, 50 are inserted within the first gap 40 in their respective positions, they are spaced apart from one another in the first direction F _D and cooperate to define the second gap 90 therebetween, as discussed above. The first end member 100 is then inserted into the opening 70 defined by the respective recessed portions 56, 58 of the first and second side edge members 48, 50. Once the first end member 100 is received within the opening 70, the first end member 100 is moved, e.g., slid, in the circumferential direction C _D such that the opposed tongue members 104, 106 of the first end member 100 are received within the respective grooves 74, 76 of the first and second side edge members 48, 50. Once the first end member 100 is fully inserted up to the adjacent blade structure 22, radial movement of the first end member 100 relative to the first and second side edge members 48, 50 is substantially prevented.

The second end member 102 is then inserted into the opening 70 defined by the respective recessed portions 56, 58 of the first and second side edge members 48, 50. Once the second end member 102 is received within the opening 70, the second end member 102 is moved, e.g., slid, in the circumferential direction C _D away from the first end member 100, such that the opposed tongue members 108, 1 10 of the second end member 102 are received within the respective grooves 74, 76 of the first and second side edge members 48, 50. Once the second end member 102 is fully inserted up to the adjacent blade structure 22, radial movement of the second end member 102 relative to the first and second side edge members 48, 50 is substantially prevented. As shown in Fig. 3, once the first and second end members 100, 102 are inserted within the second gap 90 in their respective positions, they are spaced apart from one another in the circumferential direction C _D and cooperate to define the third gap 122 therebetween, as discussed above.

The cap member 130 is then installed into the opening 70 defined by the recessed portions 56, 58 of the first and second side edge members 48, 50 so as to cover the third gap 122. Once the cap member 1 30 is received within the opening 70 and seated on the recessed portions 56, 58, the cap member is rotated, e.g.., via an appropriate tool (not shown) engaging a slot 142 formed in a top surface 144 of the cap member 130, such that the opposed first and second notches 132, 134 of the cap member 130 receive the respective projections 1 14, 1 16 of the first and second end members 100, 102, see Fig. 7. At this point, rotation of the cap member 130 is ceased, and opposed edge portions 146, 148 of the cap member 130 (see Figs. 3 and 6) are secured to the first and second side edge members 48, 50, e.g., by peening, to prevent further rotation of the cap member 1 30 within the opening 70. The reception of the projections 1 14, 1 16 of the first and second end members 100, 102 in the respective notches 132, 134 substantially prevents radial movement of the cap member 130 relative to the first and second end members 100, 102 and secures the entire locking spacer assembly 44 in place within the first gap 40.

The locking spacer assembly 44 described herein is believed to be

advantageous over prior art, threaded locking spacer assemblies, which are prone to damage/breaking at the location of the threads, since the locking spacer assembly 40 of the present invention lacks such threads.

While a particular embodiment of the present invention has been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.