US3841794A - Snap-on lock for turbomachinery blades - Google Patents
Snap-on lock for turbomachinery blades Download PDFInfo
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- US3841794A US3841794A US00448796A US44879674A US3841794A US 3841794 A US3841794 A US 3841794A US 00448796 A US00448796 A US 00448796A US 44879674 A US44879674 A US 44879674A US 3841794 A US3841794 A US 3841794A
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- disc
- slot
- blade
- extending
- circumferentially
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
- F01D5/30—Fixing blades to rotors; Blade roots ; Blade spacers
- F01D5/32—Locking, e.g. by final locking blades or keys
- F01D5/326—Locking of axial insertion type blades by other means
Definitions
- ABSTRACT A snap-on lock for turbomachinery blade including a spring snap-on member shaped to engage a circumferential slot in the blade root and to overlap the disc surface when so engaged and to further frictionally engage the side surfaces of the blade root so as to prevent axial movement of the blade within the disc retaining slot and which will be acted upon by centrifugal force to be more securely retained in the blade root circumferential slot.
- the blade retaining prior art includes many mechanisms such as Manning U.S. Pat. No. 3,341,174; Keller et al. U.S. Pat. No. 2,994,507; Hill U.S. Pat. No. 2,755,062; Newton et al. U.S. Pat. No. 2,865,076; and Pancoe U.S. Pat. No. 1,949,027, most of which require special machining of the blade and/or disc to perform their retaining functions but none of which are of the snap-on variety and operable to be retained in locking position by centrifugal force.
- a primary object of the present invention is to provide a blade retaining mechanism which locks the blade in the disc, which is capable of being installed with a minimum of effort, which may be readily removed, which is reusable, which is durable, and which is inexpensive to produce.
- FIG. I is a showing of a turbomachinery rotor with a support disc having peripheral blades extending therefrom.
- FIG. 4 is a partial showing of the blade-to-disc connection to illustrate my lock retaining slot with the lock member removed therefrom.
- FIG. 6 is a showing of a blade root to illustrate its cross-sectional shape.
- FIG. 7 is a Figure corresponding to FIG. 1 of a modified form of my invention.
- rim 20 includes a plurality of blade retaining slots 31), one for each blade, which may extend axially through rim 20 or at an angle to the axis, as desired, to properly position blades 16 with respect to cooperating apparatus (not shown) and as used herein the terms axially extending" and axial means either of these arrangements.
- Disc slot 30 and blade root 44 extend in the same direction.
- Blade 16 includes an airfoil portion 42 (see FIG. 2) positioned between the blade root 44 and the blade tip (not shown). Blade root 44 is shaped selectively in cross section as best shown in FIG. 3 to matingly be received in and engage disc slot 30 so as to secure blade 16 in radial position during rotor rotation.
- blade root 44 includes a bulbous or mushroomed shape radially inner end or base 46 which extends circumferentially when the blade is inserted into the disc and further includes substantially radially extending side surfaces 48 and 50 together with converging surfaces 52 and 54 positioned therebetween. It will be noted that in cross section blade root 44 is substantially the same shape as disc slot 30 so that the blade may be inserted into the disc for support therefrom by axially inserting blade root portions 44 into disc slot 30 commencing at one of the rim lateral surfaces 26 and proceeding toward the other 28. In the preferred embodiment disclosed herein, the bladeroot 44 commences to be axially inserted into disc slot 30 at disc surface 26 and is moved within the slot toward disc surface 28 until the blade 16 reaches its FIG. 2 fully inserted position wherein substantially radially extending surface 56 of blade stop tab 58 abuts disc surface 26 to prevent further movement of blade 16 toward disc surface 28.
- slotdefming mechanism 60 which is preferably an integral extension of root 44, as is stop 58.
- Slot 62 extends through slot defining mechanism 60 and, with the blade assembled onto the disc as best shown in FIGS. 2 and-3, slot 62 is circumferentially extending and includes a first wall 64 (see FIG. 4) which is in radial alignment with rim surface 28 and a second wall 66 spaced axially therefrom to define the slot axial dimension a therebetween.
- slot 62 is a straight slot which is machined in any convenient fashion, such as grinding, milling or chemically, in root 44 of each blade 16.
- the slots 62 extend in a substantially circumferential direction and are so described herein, althought it should be borne in mind that the slot is preferably straight, as opposed to curved.
- slot 62 cuts into blade root bulbous end 46 up to the point of the slot base 68 so that circumferentially extending projections 70 and 72 are located in blade root 44 between slot base 68 and blade side surfaces 48 and 50.
- both lock member 74, blade root 44, and disc slot 30 are symmetric about radial line 90 which passes through the midcircumferential position of disc slot 30.
- blade root section 44' includes axially extending slots opening onto the base 102 thereof.
- Lock retainer 104 is received in slot 100 and shaped to matingly engage slot 100.
- Projection 106 extends from one end of retainer 104 and is shaped so that radially extending surface 108 thereof engages radial surface 26' of disc 12' to prevent axial motion of retainer 104 in a first axial direction.
- Retainer 104 extends beyond disc surface 28 in the same fashion as slot defining mechanism 60 and is shaped to have circumferentially extending recesses 110 and 112 extending in alignment toward each other from the opposite circumferential surfaces 114 and 116, respectively, of retainer 104.
- FIG. 1-6 embodiment is similar to the FIG. 1-6 embodiment.
- a root section of substantially the same axial dimension as said disc rim portion so that the axial ends of each blade root section so positioned in its disc slot will substantially align with the rim portion radial surfaces and being of selected cross-sectional shape so as to be matingly received in said disc slot to prevent radial movement of the blade relative to the disc member and having circumferentially spaced side surfaces when so positioned in its disc slot,
- stop means operative to prevent said blade member from moving in a first axial direction within said disc slot
- a snap-on lock member shaped to snap over said circumferential projections and to be wedged into said retaining slot and to abuttingly engage the disc radial surface so as to prevent movement of the blade within the disc slot in an axial direction opposite to said first axial direction and so that centrifugal force will apply a retaining force on the snap-on lock member in said retaining slot during rotor rotation.
- a rotor according to claim 1 wherein said disc slot and said blade root section are shaped in cross section to be symmetric about a radially extending line extending through the circumferential midpoint thereof and to mushroom circumferentially at their radially inner ends and to present converging surfaces extending between the mushroom portion and for a selected radial distance outwardly thereof to provide abutting bladeto-disc blade retention surfaces in opposition to centrifugal force, and wherein said retaining slot'extends circumferentially in said mushroom portion of said blade root section and terminates at its outer radial end radially inwardly of said root section side surfaces so that the blade root section presents circumferentially extending projections at the station of the retaining slot projecting circumferentially from opposite circumferential sides of the blade root section side surfaces.
- a rotor according to claim 3 wherein said snap-on lock is a spring-rod member shaped to snap over said blade root section circumferential projections and into said blade root section retaining slot, and is further shaped to project over and abut said rim portion radial surfaces and further to engage the base of said retaining slot and to engage the side surfaces of said root section.
- a rotor according to claim 4 wherein said snap-on lock member is shaped to include a first loop which overlaps one of the radial surfaces of the rim portion of the disc, two circumferentially outwardly extending loops which overlap the blade root section circumferential projections, and two circumferentially inwardly directed loops which have less unsprung circumferential separation that the circumferential separation between said blade root section side surfaces and which snap over said root section circumferential projections and which frictionally engage the blade root section side surfaces.
- dovetail connecting means connecting each blade to the disc periphery so as to position the blades circumferentially on the disc to be radially extending and restrained during rotation and so as to permit axial movement of the blade into position and for disassembly from the disc when unrestrained, and
- snap-on lock means shaped to snap over said circumferential projections and to frictionally engage the sides of the blade root and to be snugly received into said circumferential slot and so as to be more firmly retained in said slot in response to the centrifugal force generated by disc rotation and, further, to overlap the disc surface so aligned with the slot.
- a rim portion extending circumferentially around the outer periphery of said disc member and having substantially radial surfaces at the axial ends thereof, a plurality of substantially axially extending and circumferentially spaced disc slots in said disc rim portion and extending for the full axial dimension of the rimmed portion and opening into said radial surfaces and being of selected crosssectional shape to be greater in-circumferential dimension at a slot base station nearer the axis than at a station farther from the axis,
- a retainer member shaped to be matingly received in the blade root section slot and having aligned circumferentially extending recesses projecting toward each other from the opposite circumferentially spaced and axially extending sides thereof and positioned in alignment with the circumferentially extending slot of the retaining slot defining member, and
- a snap-on lock member shaped to snap over said circumferential projections and to be wedged into said blade root section retaining slot and said retainer member recesses and to abuttingly engage the disc radial surface so as to prevent movement of the blade within the disc slot in an axial direction opposite to said first axial direction and so that centrifugal force will apply a retaining force on the snap-on lock member in said retaining slot during rotor rotation.
- blade axial retention means including:
- stop means operative to prevent the blade from moving in a first axial direction within the disc
- snap-on lock means shaped to snap over said circumferential projections and to frictionally engage the sides of the blade root and to be snugly received into said blade root circumferential slot and said retainer member recesses and so as to be more firmly retained in said slot and recesses in response to the centrifugal force generated by disc rotation and, further, to overlap the disc surface so aligned with the slot.
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- Turbine Rotor Nozzle Sealing (AREA)
Abstract
A snap-on lock for turbomachinery blade including a spring snapon member shaped to engage a circumferential slot in the blade root and to overlap the disc surface when so engaged and to further frictionally engage the side surfaces of the blade root so as to prevent axial movement of the blade within the disc retaining slot and which will be acted upon by centrifugal force to be more securely retained in the blade root circumferential slot.
Description
United States Patent [191 Bergmann 1 SNAP-ON LOCK FOR TURBOMACHINERY BLADES [75] Inventor: Richard J. Bergmann, Vernon,
Conn.
[73] Assignee: United Aircraft Corporation, East Hartford, Conn.
[451 Oct. 15, 1974 2,994,507 8/1961 Keller et a1. 416/221 3,008 689 11/1961 Morley et a1. 416/221 3,341,174 9/1967 Manning 416/220 Primary Examiner-Everette A. Powell, Jr. Attorney, Agent, or Firm-Vernon F. Hauschild [5 7 ABSTRACT A snap-on lock for turbomachinery blade including a spring snap-on member shaped to engage a circumferential slot in the blade root and to overlap the disc surface when so engaged and to further frictionally engage the side surfaces of the blade root so as to prevent axial movement of the blade within the disc retaining slot and which will be acted upon by centrifugal force to be more securely retained in the blade root circumferential slot.
11 Claims, 9 Drawing Figures PATENIEUDET 151914 sum 10? 2 F/6.Z F// SNAP-ON LOQK FOR TURBOMACHINERY BLADES BACKGROUND OF THE INVENTION 1. Field of Invention This invention relates to the retention of removable blades in discs of turbomachinery and particularly to retaining mechanism which is flexible and which may be snapped into position and, further, which is urged into proper position by centrifugal force during rotation of the rotor.
2. Description of the Prior Art The blade retaining prior art includes many mechanisms such as Manning U.S. Pat. No. 3,341,174; Keller et al. U.S. Pat. No. 2,994,507; Hill U.S. Pat. No. 2,755,062; Newton et al. U.S. Pat. No. 2,865,076; and Pancoe U.S. Pat. No. 1,949,027, most of which require special machining of the blade and/or disc to perform their retaining functions but none of which are of the snap-on variety and operable to be retained in locking position by centrifugal force.
Other prior art utilizes a tablock which is fitted between the discs and the blade at the bottom of the disc blade retaining slot and in which blade locking is accomplished by deforming the ears of the tablock at the front and rear interface of the disc and blade. This tablock mechanism sometimes results in improperly locked parts and tablock ears are prone to crack off in usage or upon blade replacement.
SUMMARY OF THE INVENTION A primary object of the present invention is to provide a blade retaining mechanism which locks the blade in the disc, which is capable of being installed with a minimum of effort, which may be readily removed, which is reusable, which is durable, and which is inexpensive to produce.
It is still a further object of the present invention to teach such a blade lock which operates by a snap-on action to perform a blade locking function and which is acted upon by centrifugal force to retain the lock in position.
It is still a further object of the present invention to teach such a snap-on lock shaped to be positioned in a circumferentially extending slot in the blade root while overlapping the disc rim and frictionally engaging the blade root to retain the lock in position.
It is still a further object of the present invention to teach such a blade lock which may be used either at one axial end of a blade in combination with any other type of blade axially retainer at the opposite bladeend or which may be used at both ends of the blade.
It is a further object of the present invention to teach such a blade lock which does not interfere with the installation of the blade in the disc, which does not require special machining of the disc, and which is'of generally of U-shape cross section and fabricated of spring rod material to be snapped over circumferentially extending projections on the blade root, and into position into a circumferentially extending slot in the blade root and, while overlapping the disc rim to thereby retain the blade in position.
It is a further object of the present invention to teach a modified form of this blade lock which requires minimal machining of the disc and blade and which utilizes the same snap-on lock member as in the preferred embodiment. In this construction, a retainer mechanism is shaped to be received matingly in an axially extending slot in the base of the blade so as to thereby be positioned when assembled between the disc and the blade. The retainer mechanism extends beyond the disc retainer slot with the blade root and includes circumferentially extending recesses in opposite sides thereof which are aligned when assembled with the circumferential slot in the blade root so that the snap-on lock of my invention is received both in the circumferentially extending recesses of the retainer mechanism and the circumferential slot of the blade root so as to lock the blade in axial position when the snap-lock member is so engaged and overlaps the disc radial surfaces. The retainer mechanism also preferably is shaped to include a retainer lug at the opposite end from its circumferential recesses which is shaped to engage the other radial surface of the disc to prevent blade axial motion in the direction opposite to that being restrained by the snapon lock member.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a showing of a turbomachinery rotor with a support disc having peripheral blades extending therefrom.
FIG, 2 is a partial, enlarged showing of a blade assembled in the disc, and showing my blade lock system as sembled.
FIG. 3 is a showing through line 3-3 of FIG. 2.
FIG. 4 is a partial showing of the blade-to-disc connection to illustrate my lock retaining slot with the lock member removed therefrom.
FIG. 5 is a partial showing of the disc to illustrate the blade retaining slot shape.
FIG. 6 is a showing of a blade root to illustrate its cross-sectional shape.
FIG. 7 is a Figure corresponding to FIG. 1 of a modified form of my invention.
FIG. 8 is a view taken along section line 8-8 of FIG. 7.
FIG. 9 is a view taken along section line 99 of FIG.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 we see a typical turbomachinery rotor 10 which includes a structural disc 12 which is concentric about and adapted to be mounted about for rotation about axis 14 and which further includes a plurality of blades 16 attached to the outer periphery thereof for rotation therewith about axis 14. The construction of turbomachinery rotors of the type which may be used in turbines or compressors or free turbines driven by fluids, such as steam or gas, is very well known and will not be described in any further detail herein. For a more complete description of aconstruction of a turbomachinery rotor, reference is hereby made to U.S. Pats. Nos. 2,711,631 and 2,747,367.
Now referring to FIGS. 2 through 4', we see a blade 16 projecting from disc 12 and while a single blade is illustrated, it should'be borne in mind that in conventional fashion there are a plurality of such radially 'extending blades positioned in spaced circumferential relationship about the periphery of disc 12. Disc 12 comprises a central web member 18 which supports rim 20. Rim 20 extends circumferentially about the periphery of disc 12 and may include circumferential flange members 22 and 24 which serve to cooperate with adjacent members (not shown) for gas sealing and other purposes. Rim 20 includes substantially radially and circumferentially extending surface 26 at its axially forward end and substantially radially and circumferentially extending surface 28 at its axially after end.
As best shown in FIG. 5, rim 20 includes a plurality of blade retaining slots 31), one for each blade, which may extend axially through rim 20 or at an angle to the axis, as desired, to properly position blades 16 with respect to cooperating apparatus (not shown) and as used herein the terms axially extending" and axial means either of these arrangements. Disc slot 30 and blade root 44, of course, extend in the same direction.
As best shown in FIG. 6, blade root 44 includes a bulbous or mushroomed shape radially inner end or base 46 which extends circumferentially when the blade is inserted into the disc and further includes substantially radially extending side surfaces 48 and 50 together with converging surfaces 52 and 54 positioned therebetween. It will be noted that in cross section blade root 44 is substantially the same shape as disc slot 30 so that the blade may be inserted into the disc for support therefrom by axially inserting blade root portions 44 into disc slot 30 commencing at one of the rim lateral surfaces 26 and proceeding toward the other 28. In the preferred embodiment disclosed herein, the bladeroot 44 commences to be axially inserted into disc slot 30 at disc surface 26 and is moved within the slot toward disc surface 28 until the blade 16 reaches its FIG. 2 fully inserted position wherein substantially radially extending surface 56 of blade stop tab 58 abuts disc surface 26 to prevent further movement of blade 16 toward disc surface 28.
At the opposite end of blade root 14 from stop 58 is retaining slotdefming mechanism 60 which is preferably an integral extension of root 44, as is stop 58. Slot 62 extends through slot defining mechanism 60 and, with the blade assembled onto the disc as best shown in FIGS. 2 and-3, slot 62 is circumferentially extending and includes a first wall 64 (see FIG. 4) which is in radial alignment with rim surface 28 and a second wall 66 spaced axially therefrom to define the slot axial dimension a therebetween. Preferably, slot 62 is a straight slot which is machined in any convenient fashion, such as grinding, milling or chemically, in root 44 of each blade 16. When the blades 16 are assembled disc 12, the slots 62 extend in a substantially circumferential direction and are so described herein, althought it should be borne in mind that the slot is preferably straight, as opposed to curved.
By viewing FIG. 3, it will be noted that slot 62, at the FIG. 3 station, cuts into blade root bulbous end 46 up to the point of the slot base 68 so that circumferentially extending projections 70 and 72 are located in blade root 44 between slot base 68 and blade side surfaces 48 and 50. I
As best shown in FIGS. 2 and 3, snap-on lock member 74, which is of generally U-shaped cross section, is snapped over circumferential projections 70 and 72 and into retaining slot 62 such that it is snugly received in slot 62 since its axial dimension and the axially dimension a of the slot 62 are substantially the same and bears against both slot surface 64 and rim surface 28, as well as slot surface 66, so as to prevent blade 16 from moving toward rim surface 26 and thereby cooperates with positive stop member 58 to position blade 16 in axial position. As best shown in FIG. 3, snap-on lock member 74, which is preferably made of spring steel and in rod form, includes a first loop 76 which projects radially inwardly from slot 62 to overlap and abut rim surface 28, further includes circumferentially outwardly extending loops 78 and 80, which envelop circumferential projections 70 and 72,-respectively, and still further includes circumferentially inwardly directed loops 82 and 84, which frictionally engage blade root side surfaces 48 and 50, respectively, since their unsprung circumferential spacing is less than the circumferential spacing between blade root surfaces 48 and 50. In view of the fact that slot 62 is radially inwardly directed, and because snap-on lock member 74 has its open end positioned in a radially outwardly direction, centrifugal force will act during rotor rotation to impose a retaining force upon lock 74 and will serve to hold straight portions 86 and 88 thereof firmly against the base 68 of slot 62.
As best shown in FIG. 3, it should'be noted that both lock member 74, blade root 44, and disc slot 30 are symmetric about radial line 90 which passes through the midcircumferential position of disc slot 30.
FIGS. 7-9 show another embodiment of my blade lock which is generally similar in all respects to the embodiment shown in FIGS. 1-6 except that a retainer member is positioned in an axially extending slot in the base of the blade root, which retainer member has circumferentially extending recesses which are aligned with the circumferentially extending blade root slot so as to receive the snap-on lock member and cooperate therewith in preventing blade axial motion in a first direction and including a projection at its opposite end which prevents blade axialmovement in the opposite direction. In describing the specifics of the FIG. 7-9 embodiment, the same reference numerals will be used to describe parts which correspond to FIGS. 1-6 embodiment but in primed form. In FIG. 7-9 embodiment,
blade root section 44' includes axially extending slots opening onto the base 102 thereof. Lock retainer 104 is received in slot 100 and shaped to matingly engage slot 100. Projection 106 extends from one end of retainer 104 and is shaped so that radially extending surface 108 thereof engages radial surface 26' of disc 12' to prevent axial motion of retainer 104 in a first axial direction. Retainer 104 extends beyond disc surface 28 in the same fashion as slot defining mechanism 60 and is shaped to have circumferentially extending recesses 110 and 112 extending in alignment toward each other from the opposite circumferential surfaces 114 and 116, respectively, of retainer 104. Recesses 110 and 112 align with blade root circumferentially extending slots 62' and are of selected axial dimension so as to snugly receive snapon lock member 74, which now engages recesses 110 and 112 as well as circumferential slot 62' and continues to overlap and abut disc radial surface 28'. In all other respects the FIG. 7-9.
embodiment is similar to the FIG. 1-6 embodiment.
It will therefore be seen that my constructions lock blades 16 onto disc 12 in such a way that each blade is radially, circumferentially and axially retained. In addition, my snap-on blade lock 74 is both frictionally engaged in position by its own resiliency but is also aided by centrifugal force during rotor rotation to remain in position. Further, my lock member 74 can be used either at one end of the blade root 44 withany other type of blade axial retainer at the opposite end, or at both ends of the blade root 44 if it is desired to have a construction in which the blades can be inserted and removed from either axial side of the disc. Further, my snap-on lock member 74 is inexpensive to manufacture, is durable, is easily assembled into the blade-disc combination, is easily withdrawn therefrom and replaced, and is reusable.
I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.
I claim:
I. A turbomachinery rotor including in combination:
A. a support disc member concentric about an axis and having:
l. a rim portion extending circumferentially around the outer periphery of said disc member and having substantially radial surfaces at the axial ends thereof,
2. a plurality of substantially axially extending and circumferentially spaced disc slots in said disc rim portion and extending for the full axial dimension of the rimmed portion and opening into said radial surfaces and being of selected crosssectional shape to be greater in circumferential dimension at a station nearer the axis than at a station farther from the axis,
B. a plurality of blade members each received in one of said disc slots and having:
1. a root section of substantially the same axial dimension as said disc rim portion so that the axial ends of each blade root section so positioned in its disc slot will substantially align with the rim portion radial surfaces and being of selected cross-sectional shape so as to be matingly received in said disc slot to prevent radial movement of the blade relative to the disc member and having circumferentially spaced side surfaces when so positioned in its disc slot,
C. stop means operative to prevent said blade member from moving in a first axial direction within said disc slot,
D. a retaining slot defining member located at an axial end of the blade root section and shaped to define a substantially circumferentially extending retaining slot opening toward the axis and being of selected axial dimension and having a first wall thereof extending substantially radially and in alignment with the rim portion radial surface at that radial end of the disc rim portion and having a second wall in selected axial spaced relation to the first wall to define the retaining slot axial dimension therebetween, and further being shaped to define circumferential projections radially outward of the slot,
E. a snap-on lock member shaped to snap over said circumferential projections and to be wedged into said retaining slot and to abuttingly engage the disc radial surface so as to prevent movement of the blade within the disc slot in an axial direction opposite to said first axial direction and so that centrifugal force will apply a retaining force on the snap-on lock member in said retaining slot during rotor rotation.
2. A rotor according to claim 1 wherein said stop means is attached to one end of said root section and is shaped topresent a substantially radially extending surface dimensioned to abut the disc rim radial surface when the blade root section is so inserted into said disc slot to prevent further movement of the blade in the direction of insertion.
3. A rotor according to claim 1 wherein said disc slot and said blade root section are shaped in cross section to be symmetric about a radially extending line extending through the circumferential midpoint thereof and to mushroom circumferentially at their radially inner ends and to present converging surfaces extending between the mushroom portion and for a selected radial distance outwardly thereof to provide abutting bladeto-disc blade retention surfaces in opposition to centrifugal force, and wherein said retaining slot'extends circumferentially in said mushroom portion of said blade root section and terminates at its outer radial end radially inwardly of said root section side surfaces so that the blade root section presents circumferentially extending projections at the station of the retaining slot projecting circumferentially from opposite circumferential sides of the blade root section side surfaces.
4. A rotor according to claim 3 wherein said snap-on lock is a spring-rod member shaped to snap over said blade root section circumferential projections and into said blade root section retaining slot, and is further shaped to project over and abut said rim portion radial surfaces and further to engage the base of said retaining slot and to engage the side surfaces of said root section.
5. A rotor according to claim 4 wherein said snap-on lock member is shaped to include a first loop which overlaps one of the radial surfaces of the rim portion of the disc, two circumferentially outwardly extending loops which overlap the blade root section circumferential projections, and two circumferentially inwardly directed loops which have less unsprung circumferential separation that the circumferential separation between said blade root section side surfaces and which snap over said root section circumferential projections and which frictionally engage the blade root section side surfaces.
6. A rotor according to claim 5 wherein said snap-on lock member is concentric about a radially extending line extending through the mid-circumferential station of said blade root portion when so snapped into position and including straight sections on opposite sides of said radial line engaging the retaining slot base.
7. A turbomachinery rotor including:
A. a disc having an axis and adapted to be mounted for rotation thereabout,
B. a plurality of vanes adapted to be connected to the outer periphery of the disc,
C. dovetail connecting means connecting each blade to the disc periphery so as to position the blades circumferentially on the disc to be radially extending and restrained during rotation and so as to permit axial movement of the blade into position and for disassembly from the disc when unrestrained, and
D. blade axial retention means including:
1. stop means operative to prevent the blade from moving'in a first axial direction within the disc,
2. means defining a circumferentially extending slot in the blade root in alignment with the disc surface adjacent that end of the root and including circumferentially extending projections at the base of the circumferential slot, and
3. snap-on lock means shaped to snap over said circumferential projections and to frictionally engage the sides of the blade root and to be snugly received into said circumferential slot and so as to be more firmly retained in said slot in response to the centrifugal force generated by disc rotation and, further, to overlap the disc surface so aligned with the slot.
8. A turbomachinery rotor including in combination:
A. a support disc member concentric about an axis and having:
1. a rim portion extending circumferentially around the outer periphery of said disc member and having substantially radial surfaces at the axial ends thereof, a plurality of substantially axially extending and circumferentially spaced disc slots in said disc rim portion and extending for the full axial dimension of the rimmed portion and opening into said radial surfaces and being of selected crosssectional shape to be greater in-circumferential dimension at a slot base station nearer the axis than at a station farther from the axis,
B. a plurality of blade members each received in one of said disc slots and having:
1. a root section of substantially the same axial dimension as said disc rim portion so that the axial ends of each blade root section so positioned in its disc slot will substantially align with the rim portion radial surfaces and being of selected cross-sectional shape so as to be matingly received in said disc slot to prevent radial and circumferential movement of the blade relative to the 'disc member and having circumferentially spaced side surfaces and a base adjacent the disc slot base when so positioned in its disc slot, and further having an axially extending slot opening into the base thereof.
C. stop means operative to prevent said blade member from moving in a first axial direction within said disc slot,
D. a retaining slot defining member located at an axial end of the blade root section and shaped to define a substantially circumferentially extending retaining slot opening toward the axis and being of selected axial dimension and having a first wall thereof extending substantially radially and in alignment with the rim portion radial surface at that radial end of disc rim portion and having a second wall in selected axial spaced relation to the first wall to define the retaining slot axial dimension therebetween, and further being shaped to define circumferential projections radially outward of the slot,
E. a retainer member shaped to be matingly received in the blade root section slot and having aligned circumferentially extending recesses projecting toward each other from the opposite circumferentially spaced and axially extending sides thereof and positioned in alignment with the circumferentially extending slot of the retaining slot defining member, and
F. a snap-on lock member shaped to snap over said circumferential projections and to be wedged into said blade root section retaining slot and said retainer member recesses and to abuttingly engage the disc radial surface so as to prevent movement of the blade within the disc slot in an axial direction opposite to said first axial direction and so that centrifugal force will apply a retaining force on the snap-on lock member in said retaining slot during rotor rotation.
9. A rotor according to claim 8 wherein the stop means is a projection extending from the retaining member and shaped to engage the disc radial surface opposite the disc radial surface engaged by the snap-on lock member.
10. A turbomachinery rotor including:
A. a disc having an axis and adapted to be mounted for rotation thereabout,
B. a plurality of vanes adapted to be connected to the outer periphery of the disc,
C. dovetail connecting means connecting each blade to the disc periphery so as to position the blades circumferentially on the disc to be radially extending and restrained during rotation and so as to permit axial movement of the blade into position and for disassembly from the disc when unrestrained, and
D. blade axial retention means including:
1. stop means operative to prevent the blade from moving in a first axial direction within the disc,
2. means defining a circumferentially extending slot in the blade root in alignment with the disc surface adjacent that end of the root and including circumferentially extending projections at the base of the circumferential slot,
3. means defining an axially extending slot in the blade root and opening onto the base thereof, 4. a retainer member shaped to be matingly received in the blade root axial slot and having aligned circumferentially extending recesses projecting toward each other from the opposite circumferentially spaced and axially extending sides thereof and positioned in alignment with the blade root circumferentially extending slot,
5. snap-on lock means shaped to snap over said circumferential projections and to frictionally engage the sides of the blade root and to be snugly received into said blade root circumferential slot and said retainer member recesses and so as to be more firmly retained in said slot and recesses in response to the centrifugal force generated by disc rotation and, further, to overlap the disc surface so aligned with the slot.
11. A rotor according to claim 10 wherein the stop
Claims (19)
1. A turbomachinery rotor including in combination: A. a sUpport disc member concentric about an axis and having: 1. a rim portion extending circumferentially around the outer periphery of said disc member and having substantially radial surfaces at the axial ends thereof, 2. a plurality of substantially axially extending and circumferentially spaced disc slots in said disc rim portion and extending for the full axial dimension of the rimmed portion and opening into said radial surfaces and being of selected cross-sectional shape to be greater in circumferential dimension at a station nearer the axis than at a station farther from the axis, B. a plurality of blade members each received in one of said disc slots and having: 1. a root section of substantially the same axial dimension as said disc rim portion so that the axial ends of each blade root section so positioned in its disc slot will substantially align with the rim portion radial surfaces and being of selected cross-sectional shape so as to be matingly received in said disc slot to prevent radial movement of the blade relative to the disc member and having circumferentially spaced side surfaces when so positioned in its disc slot, C. stop means operative to prevent said blade member from moving in a first axial direction within said disc slot, D. a retaining slot defining member located at an axial end of the blade root section and shaped to define a substantially circumferentially extending retaining slot opening toward the axis and being of selected axial dimension and having a first wall thereof extending substantially radially and in alignment with the rim portion radial surface at that radial end of the disc rim portion and having a second wall in selected axial spaced relation to the first wall to define the retaining slot axial dimension therebetween, and further being shaped to define circumferential projections radially outward of the slot, E. a snap-on lock member shaped to snap over said circumferential projections and to be wedged into said retaining slot and to abuttingly engage the disc radial surface so as to prevent movement of the blade within the disc slot in an axial direction opposite to said first axial direction and so that centrifugal force will apply a retaining force on the snap-on lock member in said retaining slot during rotor rotation.
2. a plurality of substantially axially extending and circumferentially spaced disc slots in said disc rim portion and extending for the full axial dimension of the rimmed portion and opening into said radial surfaces and being of selected cross-sectional shape to be greater in circumferential dimension at a slot base station nearer the axis than at a station farther from the axis, B. a plurality of blade members each received in one of said disc slots and having:
2. means defining a circumferentially extending slot in the blade root in alignment with the disc surface adjacent that end of the root and including circumferentially extending projections at the base of the circumferential slot,
2. a plurality of substantially axially extending and circumferentially spaced disc slots in said disc rim portion and extending for the full axial dimension of the rimmed portion and opening into said radial surfaces and being of selected cross-sectional shape to be greater in circumferential dimension at a station nearer the axis than at a station farther from the axis, B. a plurality of blade members each received in one of said disc slots and having:
2. A rotor according to claim 1 wherein said stop means is attached to one end of said root section and is shaped to present a substantially radially extending surface dimensioned to abut the disc rim radial surface when the blade root section is so inserted into said disc slot to prevent further movement of the blade in the direction of insertion.
2. means defining a circumferentially extending slot in the blade root in alignment with the disc surface adjacent that end of the root and including circumferentially extending projections at the base of the circumferential slot, and
3. snap-on lock means shaped to snap over said circumferential projections and to frictionally engage the sides of the blade root and to be snugly received into said circumferential slot and so as to be more firmly retained in said slot in response to the centrifugal force generated by disc rotation and, further, to overlap the disc surface so aligned with the slot.
3. A rotor according to claim 1 wherein said disc slot and said blade root section are shaped in cross section to be symmetric about a radially extending line extending through the circumferential midpoint thereof and to mushroom circumferentially at their radially inner ends and to present converging surfaces extending between the mushroom portion and for a selected radial distance outwardly thereof to provide abutting blade-to-disc blade retention surfaces in opposition to centrifugal force, and wherein said retaining slot extends circumferentially in said mushroom portion of said blade root section and terminates at its outer radial end radially inwardly of said root section side surfaces so that the blade root section presents circumferentially extending projections at the station of the retaining slot projecting circumferentially from opposite circumferential sides of the blade root section side surfaces.
3. means defining an axially extending slot in the blade root and opening onto the base thereof,
4. a retainer member shaped to be matingly received in the blade root axial slot and having aligned circumferentially extending recesses projecting toward each other from the opposite circumferentially spaced and axially extending sides thereof and positioned in alignment with the blade root circumferentially extending slot,
4. A rotor according to claim 3 wherein said snap-on lock is a spring-rod member shaped to snap over said blade root section circumferential projections and into said blade root section retaining slot, and is further shaped to project over and abut said rim portion radial surfaces and further to engage the base of said retaining slot and to engage the side surfaces of said root section.
5. A rOtor according to claim 4 wherein said snap-on lock member is shaped to include a first loop which overlaps one of the radial surfaces of the rim portion of the disc, two circumferentially outwardly extending loops which overlap the blade root section circumferential projections, and two circumferentially inwardly directed loops which have less unsprung circumferential separation that the circumferential separation between said blade root section side surfaces and which snap over said root section circumferential projections and which frictionally engage the blade root section side surfaces.
5. snap-on lock means shaped to snap over said circumferential projections and to frictionally engage the sides of the blade root and to be snugly received into said blade root circumferential slot and said retainer member recesses and so as to be more firmly retained in said slot and recesses in response to the centrifugal force generated by disc rotation and, further, to overlap the disc surface so aligned with the slot.
6. A rotor according to claim 5 wherein said snap-on lock member is concentric about a radially extending line extending through the mid-circumferential station of said blade root portion when so snapped into position and including straight sections on opposite sides of said radial line engaging the retaining slot base.
7. A turbomachinery rotor including: A. a disc having an axis and adapted to be mounted for rotation thereabout, B. a plurality of vanes adapted to be connected to the outer periphery of the disc, C. dovetail connecting means connecting each blade to the disc periphery so as to position the blades circumferentially on the disc to be radially extending and restrained during rotation and so as to permit axial movement of the blade into position and for disassembly from the disc when unrestrained, and D. blade axial retention means including:
8. A turbomachinery rotor including in combination: A. a support disc member concentric about an axis and having:
9. A rotor according to claim 8 wherein the stop means is a projection extending from the retaining member and shaped to engage the disc radial surface opposite the disc radial surface engaged by the snap-on lock member.
10. A turbomachinery rotor including: A. a disc having an axis and adapted to be mounted for rotation thereabout, B. a plurality of vanes adapted to be connected to the outer periphery of the disc, C. dovetail connecting means connecting each blade to the disc periphery so as to position the blades circumferentially on the disc to be radially extending and restrained during rotation and so as to permit axial movement of the blade into position and for disassembly from the disc when unrestrained, and D. blade axial retention means including:
11. A rotor according to claim 10 wherein the stop means is a projection extending from the retaining member and shaped to engage the disc surface opposite the disc surface engaged by the snap-on lock member.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US00448796A US3841794A (en) | 1974-03-06 | 1974-03-06 | Snap-on lock for turbomachinery blades |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US00448796A US3841794A (en) | 1974-03-06 | 1974-03-06 | Snap-on lock for turbomachinery blades |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3841794A true US3841794A (en) | 1974-10-15 |
Family
ID=23781723
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US00448796A Expired - Lifetime US3841794A (en) | 1974-03-06 | 1974-03-06 | Snap-on lock for turbomachinery blades |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US3841794A (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4249350A (en) * | 1979-01-15 | 1981-02-10 | Goff James R | Abrasive throwing wheel and improved blade assembly |
| FR2492906A2 (en) * | 1976-03-25 | 1982-04-30 | Snecma | Retainer for movable blast vane - comprises wedge with opening to cooperate with U=shaped bolt and also cylindrical hole to which grip is fixed |
| US5160243A (en) * | 1991-01-15 | 1992-11-03 | General Electric Company | Turbine blade wear protection system with multilayer shim |
| US6494684B1 (en) * | 1999-10-27 | 2002-12-17 | Rolls-Royce Plc | Locking devices |
| US20110103960A1 (en) * | 2009-11-03 | 2011-05-05 | General Electric Company | Apparatus and method for reducing wear in disk lugs |
| US20150078907A1 (en) * | 2013-09-13 | 2015-03-19 | General Electric Company | Turbomachine including a non-destructive fastener element for joining components |
| US10145249B2 (en) | 2016-02-23 | 2018-12-04 | Mechanical Dynamics & Analysis Llc | Turbine bucket lockwire anti-rotation device for gas turbine engine |
| CN109098777A (en) * | 2018-09-05 | 2018-12-28 | 中国航发动力股份有限公司 | A kind of flue gas turbine expander disc slot is to connection structure and its application method |
| US10472298B2 (en) | 2011-06-06 | 2019-11-12 | Cool Planet Energy System, Inc. | Biochar suspended solution |
| US10508557B2 (en) * | 2016-12-23 | 2019-12-17 | Doosan Heavy Industries Construction Co., Ltd. | Gas turbine |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2755063A (en) * | 1950-11-14 | 1956-07-17 | Rolls Royce | Rotor constructions for gas-turbine engines |
| US2994507A (en) * | 1959-01-23 | 1961-08-01 | Westinghouse Electric Corp | Blade locking structure |
| US3008689A (en) * | 1954-08-12 | 1961-11-14 | Rolls Royce | Axial-flow compressors and turbines |
| US3341174A (en) * | 1967-02-27 | 1967-09-12 | United Aircraft Corp | Blade lock |
-
1974
- 1974-03-06 US US00448796A patent/US3841794A/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2755063A (en) * | 1950-11-14 | 1956-07-17 | Rolls Royce | Rotor constructions for gas-turbine engines |
| US3008689A (en) * | 1954-08-12 | 1961-11-14 | Rolls Royce | Axial-flow compressors and turbines |
| US2994507A (en) * | 1959-01-23 | 1961-08-01 | Westinghouse Electric Corp | Blade locking structure |
| US3341174A (en) * | 1967-02-27 | 1967-09-12 | United Aircraft Corp | Blade lock |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2492906A2 (en) * | 1976-03-25 | 1982-04-30 | Snecma | Retainer for movable blast vane - comprises wedge with opening to cooperate with U=shaped bolt and also cylindrical hole to which grip is fixed |
| US4249350A (en) * | 1979-01-15 | 1981-02-10 | Goff James R | Abrasive throwing wheel and improved blade assembly |
| US5160243A (en) * | 1991-01-15 | 1992-11-03 | General Electric Company | Turbine blade wear protection system with multilayer shim |
| US6494684B1 (en) * | 1999-10-27 | 2002-12-17 | Rolls-Royce Plc | Locking devices |
| US20110103960A1 (en) * | 2009-11-03 | 2011-05-05 | General Electric Company | Apparatus and method for reducing wear in disk lugs |
| US8282356B2 (en) * | 2009-11-03 | 2012-10-09 | General Electric Company | Apparatus and method for reducing wear in disk lugs |
| US10472298B2 (en) | 2011-06-06 | 2019-11-12 | Cool Planet Energy System, Inc. | Biochar suspended solution |
| US11180428B2 (en) | 2011-06-06 | 2021-11-23 | Talipot Cool Extract (Ip), Llc | Biochar suspended solution |
| US20150078907A1 (en) * | 2013-09-13 | 2015-03-19 | General Electric Company | Turbomachine including a non-destructive fastener element for joining components |
| US10145249B2 (en) | 2016-02-23 | 2018-12-04 | Mechanical Dynamics & Analysis Llc | Turbine bucket lockwire anti-rotation device for gas turbine engine |
| US10508557B2 (en) * | 2016-12-23 | 2019-12-17 | Doosan Heavy Industries Construction Co., Ltd. | Gas turbine |
| CN109098777A (en) * | 2018-09-05 | 2018-12-28 | 中国航发动力股份有限公司 | A kind of flue gas turbine expander disc slot is to connection structure and its application method |
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