Abstract: Sheet Metal thermal control dampers are disposed in the cavities between turbine blades to bear against the undersides of opposed blade platforms portions of angularly adjacent blades under centrifugal loading to dampen blade vibrations and to seal the gaps between platforms against the radial flow of working fluid into the interblade cavities. The dampers are configured to cooperate with forward and aft seals to also block the axial flow of working fluid through the interblade cavities. Holes are provided in the dampers through which cooling air introduced into the interblade cavities can flow into contact with the platform undersides and cool the platforms, thereby controlling temperature rise in the blade attachment structure.

Abstract: A non-integral rotor blade platform for a rotary machine is disclosed. Various construction details are developed which disclose a one-piece, non-integral rotor blade platform retained to a live rim area of a disk. In one embodiment, a rotor blade assembly (48) is comprised of a plurality of rotor blades (54) disposed on a disk (44), a plurality of platforms (60), each platform disposed between adjacent rotor blades, and a front cover plate (56) and rear cover plate (58) which, in conjunction, retain the platforms to the disk. In an alternative embodiment, each platform (102) has a supplemental mechanical fastener means (100) to provide additional retention of the platforms to a disk (104).

Abstract: A fan blade and rotor disk assembly for a gas turbine engine has a projection attached to a shank region of a fan blade. The projection makes contact with a surface region of a disk post when the fan blade is assembled to the rotor disk. In one form, a spring urges the fan blade to a position to maintain the projection in contact with the disk post surface so as to maintain the radial position of the fan blade. The projection member absorbs impact loading, shears off, allowing the blade to rotate and reduces the moment experienced by the root region of the fan blade when the fan blade is impacted by a foreign object.

Abstract: A rotor blade for a gas turbine engine includes an airfoil, platform and dovetail. The platform has top and bottom surfaces, with a plurality of pockets disposed in the bottom surface for reducing weight of the platform, with the pockets defining a plurality of continuous beams extending along the platform which provide structural stiffness to the platform to avoid resonance vibration thereof during operation.

Abstract: A generally wedge-shaped vibration damper for rotor blades of a gas turbine engine has a pair of scrubbing surfaces and is loosely retained in a pocket incorporated in the root cavity. The pocket is partly defined by a plurality of surfaces which orient the damper so that it is slidably displaceable and rotatable only in a predetermined plane. The retaining device is a hook-shaped sheet metal clip which is attached to the damping member. The clip has a resilient curved portion which is compressed to pass through a throat by which the pocket communicates with the remainder of the root cavity. When the curved portion of the clip clears the throat, it springs back to its uncompressed state in which the height of the curved portion is greater than the height of the throat, whereby the damping member is retained in the pocket.

Abstract: A rotor having a bladed disc and for use in a fluid flow machine has plates extending between and supported by the blades to protect the disc rim from erosion and foreign object damage and also, when the rotor is a gas turbine, to protect the disc rim from the heating effects of high temperature gasses. The plates are held between ridges on the blade faces.

Abstract: A platform motion restraint for freestanding blades having Christmas tree shaped roots comprising a plurality of L shaped members which fit in circumferential notches machined in the outer portion of rotor steeples, one leg of the L shaped member being forced into the groove under platform portions of the blade to move the blades radially outward and the other leg filling the gap between adjacent blades.

Abstract: A platform spacer is joinable to a rotor disk between adjacent rotor blades having dovetails retained in a circumferential dovetail groove therein. The spacer includes a platform having a flat upper surface sized for abutting adjacent blade platforms to form an inner flowpath, and first and second hooks extending downwardly from the platform lower surface. The first and second hooks are configured for insertion radially inwardly through first and second loading recesses in the rotor disk for retention thereto.

Abstract: An underplatform damper contact portion 54 is rigid, and provides a loose seal between the underplatform cooling air 46 and the gas stream 40. At the aft end of the blade platform the pressure difference increases and a more effective seal is provided by the snap-in flexible seal 71.

Abstract: Nonmetallic airfoil blades are mounted to a rotor disk via a circumferentially spaced array of metal support members. Each support member includes a pair or circumferentially spaced arcuate or airfoil shaped dovetail engagement surfaces. The metal support members are secured to the rotor disk via straight dovetails while the rotor blades are secured to the support members via airfoil shaped dovetails. The support members may include hollow portions for channeling cooling air to the airfoil blades.

Abstract: A fan blade damper system includes a fan disk integrally connected to a disk post. A retainer is fastened to the disk post and is molded to retain a damper block. The top portion of the damper block is shaped to make frictional contact with the underside of the platform of a fan blade, the underside of the platform being the region of the fan blade which experiences the highest platform vibratory amplitude when the fan blade is rotated. The damper block is thus mounted in a statically determinant fashion. The rotation of the fan blade produces centrifugal forces which produce reactionary forces in the damper block and retainer such that a maximum damping force amplitude is reacted to the fan disk.

Abstract: A separate inter-blade platform for a bladed rotor disk of a turbo-machine comprises a first part in the form of a four-sided frame of generally trapezoidal shape and made of a laminated material, the frame having smaller and larger ends for location on the upstream and downstream sides respectively of the rotor disk, and two lateral sides interconnecting said ends for location between successive blades of the rotor, and a second part made of a relatively flexible and self-adhesive material of the polyurethane type attached to the first part, the second part defining a plate capping the frame over the greater part of its two lateral sides and leaving the smaller and larger end portions free, a portion enclosing the two lateral sides of the frame in line with the plate, and a plurality of evenly spaced, transverse reinforcing ribs which are integral with said enclosing portion and the underside of the plate.

Abstract: The present invention provides a rotor blade capable of being axially loaded in slots on a gas turbine engine rotor and particularly suited for use on turbine disks. The blade has a generally axially extending dovetail root which is effective for being loaded into a rotor disk slot between adjacent disk posts. Anti-rock tangs are disposed radially outward of the root and tangentially extend from the shank and are generally linear in the axial direction. The anti-rock tangs are effective to engage the radially outwardmost facing surfaces of the adjacent dovetail posts between which is disposed the associated dovetail slot.

Abstract: A fan or compressor stage rotor comprises a disc, radial blades mounted in axial sockets formed in the periphery of the disc, and spacer blocks interposed between the blades to constitute the inner boundary of the air flow path through the rotor. The spacer blocks each comprise an outer wall which is spaced from the periphery of the disc, and front and rear walls extending radially inwardly to overlap at least partially the front and rear faces of the disc. The front and rear walls each comprise at least one hook which co-operates with a corresponding groove provided in the respective face of the disc to fix the spacer block to the disc. The spacer block also comprises a median partition projecting inwards from its outer wall and having a slot through which passes a leaf spring of a vibration damper.

Abstract: A freestanding mixed tuned taper-twisted steam turbine blade having an X-X axis parallel to a rotor axis, includes a root portion having a root center line defined by a root center line radius, a platform portion connected to the root portion; and an airfoil portion connected to the platform portion and having a leading edge, a trailing edge, a convex section-side surface, a concave pressure-side surface and a profiled tip, the platform portion having a concave edge, a convex edge, a first end in vertical proximity to the leading edge of the airfoil portion and a second end in vertical proximity to the trailing edge of the airfoil portion, the concave edge being sloped towards the root center line radius at a predetermined angle of slope to define an arcuate sloped surface, and having a sloped flat cut-out surface formed at the second end of the platform portion, the flat cut-out surface having the same predetermined angle of slope as the concave edge and sloping towards the X-X axis.

Abstract: A vibration damper is disposed between each adjacent pair of turbine buckets of a gas turbine engine to act in a V-shaped groove defined by bevelled platform surfaces of the adjacent buckets. The damper is wedge-shaped in cross section and is provided with a pad on one side and two pads on another side. When the damper is propelled into the groove by centrifugal force, it assumes a consistent equilibrium position with the raised surface of the one pad slidingly engaging one of the platform bevelled surfaces and the raised surfaces of the other two pads slidingly engaging the other bevelled platform surface to dissipate vibrational energy in the buckets.

Abstract: An axial flow turbomachine rotor comprises a disc having a plurality of annular flanges extending outwardly from its periphery, a plurality of blades secured to the disc and extending radially outwardly from the periphery thereof, each of the blades having its root notched to define heels which are received in the grooves formed between the annular flanges of the disc, and a plurality of separate platforms which are secured to the disc and are disposed between the blades to define the inner boundary of the fluid flow path through the rotor, the blades each being fixed to the disc by two parallel pins which are equidistance from the axis of the disc and are received in corresponding bores passing through the annular flanges and the heels of the blade, the pins also serving to secure the platforms to the disc.

Abstract: A fan for a turboshaft engine is disclosed comprising a rotatable disc having an array of blades secured at evenly spaced intervals around its periphery, each pair of successive blades and the disc defining a space which is delimited by the stem and a platform of a first of the two blades, the stem and a platform of the second of the two blades, and the periphery of the disc between the two blades.

Abstract: Each of a pair of axially spaced turbine disks (12,14) has a plurality of blade retention fingers (20) at the periphery. Each blade has a pair of chevrons (64,66), one engaging a contiguous chevron (70) on a corresponding disk finger. The interacting chevron surfaces are located on the center plane (74) of a corresponding disk. Each finger is shaped to have a linear locus (75) of neutral axis (77) from the body of the disk to the chevron location. Each blade has a hollow platform structure (24), structural members (86,88,92,94) associated with a chevron (70), an airfoil extension (63) extending through the platform (28). High temperature cooling air (34) is directed into the blades (32,26,22) while being baffled away (42) from the turbine disks (12,14). Low temperature cooling air (48) bathes the live disks.

Abstract: A gas turbine engine having an outer annular turbine rotor, which is counterrotatable relative to an inner annular turbine rotor, includes attachment structure for attaching turbine blades in circumferential rows to the inner rotor. The attachment structure includes first and second male members of hook-like configurations spaced axially along and circumferentially extending about the rotor, and first and second grooves defined by flanges attached to the rotor and axially spaced along and circumferentially extending about the rotor. The grooves open in a common axial direction for receiving in mated relation respectively and concurrently the hook-like configured first and second male members. The attachment structure also includes several different locking arrangements for locking the male members in mated relation with the grooves to thereby restrain the turbine blade against radial and axial movements relative to the rotor.

Abstract: A lightweight, integrally bladed rotor has airfoils (18) and a full hoop blade platform (26), a support ring (28) is inside and spaced from the platform, with radial webs (30) extending from the support ring to the platform. Each web is a radial extension (32) of an airfoil. A radially extending shear plate (36) is secured to the platform and the ring.

Abstract: In a gas turbine engine, a turbine blade vibration damper is located between the underside of a blade platform and a turbine disc, and comprises a member which extends axially parallel to the blade roots. The member has on its outer surface an inverted "V" shaped projection which engages a complementary shaped recess in the underside of the blade platforms. The member has two limbs of unequal length. Centrifugal forces on the longer limb rocks the member and urges the shorter limb into engagement with the disc rim.

Abstract: A bladed disc of a turbomachine rotor comprising an array of blades evenly disposed around the rim of the disc and separate platforms secured to the disc between the blades, each platform comprising a plate and a mounting foot at each axial end of the plate by which the platform is secured to the rim of the disc, at least one of the feet being secured by a C-shaped clamp which rigidly connects the foot to a tooth-like element of the disc adjacent the rim and which is locked axially in position by a flange of an adjacent element of the rotor.

Abstract: Rotor blades having roots of the hammer-head type which are received in a circumferential groove in the rim of a rotor disc to secure the blades on the disc are provided with a raised portion on the underside of the blade platform which extends over the entire circumferential length of the platform and has a width equal to that of the mouth of the groove in the rim of the disc. The root of each blade is mounted on this raised portion, and when the root is received in the groove of the disc the raised portion is received closely in the mouth of the groove to ensure the correct alignment of the blade.

Abstract: A turbine blade is designed to avoid having to machine a part of the last blade assembled in a row in order to make a fit. The location of the root pivot center was carefully selected to be located in vertical proximity to a leading edge of the platform.

Abstract: Rotor blades have feet engaged in axial grooves in a rotor disc and foot plates on the blades form with the surface of the rotor disc, axially and circumferentially extending intermediate spaces. Between sections of the blades and the rotor disc, overlaps of structural parts are developed at the intermediate spaces, by which the blades are fixed axially in the grooves in one direction. The overlaps of the structural parts can be formed between profiled or ground contours surfaces of the blade feet and profiled or broached contours surfaces of the rotor disc.

Abstract: A blade-to-blade vibration damper for a turbine rotor blade is disclosed. Each blade has airfoil, platform and root portions. A plurality of blades are circumferentially spaced about a rotor disk. An inclined recess extends into the platform portion of each blade from a first surface thereof, and toward its root portion. A U-shaped wire-form damping member has its in-turned marginal end portions slidably received in each recess. When the rotor disk is rotated at a sufficient angular speed, the damping members move outwardly by the centrifugal force acting thereon to engage the opposing surface of the platform portion of the adjacent blade. When so engaged, the members damp vibrations of such blades and seal the space between the opposing platform surfaces.

Abstract: An aerofoil balde rotor assembly in which a plurality of aerofoil blades having circumferentially extending platforms are located on the periphery of a rotatable disc. Each of the platforms is provided with tracks on its radially inner surface. The tracks of adjacent platforms define a convergent seating for a ceramic spherical damping member. Each spherical damping member frictionally engages the tracks of adjacent platforms simultaneously upon rotation of the assembly so as to provide aerofoil damping.

Abstract: Method and apparatus for assembling integral platform blade groups to a rotor of a steam turbine in which the platform roots are skewed with respect to the axis of the turbine. The platform roots are formed to define a set of spaced grooves and steeples are formed on the rotor to mate with the platform roots. Grooves on the platform and in the rotor are alignable to accept a connecting member when the steeples are aligned in abutting relationship with platform roots. The connecting member joins the blade group to the rotor. In one form, the bearing surfaces of the steeples, roots and connecting member are formed to lie on one or more circles circumscribing the rotor axis.

Abstract: Blade platforms (26) for compressor blades with airfoils (22) in high solidity relationship have edges of a major portion (44) a minor portion (46), and a canted intermediate portion (48). Minimum clearance (54) exists between the major portions (44) whereby twisting during stackup or operation is avoided. A circumferential seal (60, 64) is located under the platform coincident with major portion (44).

Abstract: In a compressor rotor assembly of an axial flow gas turbine engine, wherein the rotor disk has a circumferential blade retaining slot for receiving the root of each blade of a row of blades, a ladder seal is provided between the slot and the blade platforms to limit the leakage of working medium gases from the flow path and through the slot. During engine operation, the seal moves radially outwardly into sealing relation with the underside surface of each platform. At the same time, radially inwardly extending flanges of the seal move radially outwardly into sealing relation with the sidewalls of the disk slot.

Abstract: Damping of a turbine rotor is attained by a weighted member trapped between pockets formed in the neck of adjacent blades at one end and a space between the disk and TOBI rotor seal and forward extending blade lug at the other end. The feather seal which is a curved plate fits over the top of the weighted member and is trapped between nubs formed on the front and rear underside of the blade platform. The front face of the rim of the disk at the disk cavity is open ended and blocked off at the rear face. This assembly allows for individual blade removal and viewing from the rear face by removing a single rim cavity cover without disturbing the remaining components of the assembly. The inverted ring supports take up the axial loads alleviating the loads heretofore taken up by the TOBI rotor seal, allowing for a lighter weight installation.

Abstract: A gas turbine rotor blade platform sealing and damping system has elongated symmetrical insert elements of equilateral triangular cross-section loosely received within complementary shaped pockets at the spacing gaps between opposing convex and concave airfoil side edges of adjacently mounted blade platforms. The inserts and pockets are relatively configured to provide self-orientation of the inserts into gap sealing and vibration damping engagement with the platform edges when acted upon by centrifugal force due to rotor rotation. The convex platform edge is thickened at the point of closest proximity with the convex side of the airfoil. Alternative embodiments utilize insert grooves for increased leakage of cooling gas past the platform edges and incorporate a central bore for mass reduction.

Abstract: A locking system for blades in a circumferential dovetail groove in a rotor of a gas turbine engine, the blades having dovetail roots in the groove and platforms resting on steady rest flanges on the outside surface of the rotor on opposite sides of the slot between converging shoulders of the dovetail groove. The blade locking system includes an inner lock member between roots of a pair of adjacent blades, an outer lock member captured in aligned notches in the steady rest flanges between the rotor and the platforms of the adjacent blades, and a screw extending through a clearance hole in the outer lock member into a threaded bore in the inner lock member. When the screw is tightened, the inner and outer lock members are clamped against the rotor.

Abstract: A stator assembly for a gas turbine engine having a support structure and a stiffening ring 46 extending about the support structure 34 is disclosed. Various construction details which increase the rigidity of the support structure and enable the stiffening ring to accept axial and radial loads are developed. In one embodiment the stiffening ring 46 is the seal ring 52 for a seal end 74. In one particular embodiment, the thermal expansion characteristic of the support structure is greater than the thermal expansion characteristic of the stiffening ring to insure that the stiffening ring is in tension under normal operative conditions of the engine.

Abstract: A rotor assembly for use in a rotodynamic machine comprises a rotor disc (10) with a plurality of blades (14) attached to its outer rim (12) and a seal plate (22) for substantially preventing the escape of blade cooling air. The rotor disc (10) is provided with a plurality of hooked restraining members (30) each including a radially inward directed abutment face (32) which in use restrain the seal plate from moving axially and from moving radially outward under centrifugal force by abutment with the seal plate. In this way the blades (14) are not subjected to additional loading by the seal plate (22).

Abstract: A spiral groove machined in the end face of a turbine rotor disc accelerates boundary layer fluid flow from the interior of the turbine rotor to the compression chamber. This flow cools the rotor disc and vanes. A transverse axial passageway may be provided beneath the vane roots. Radial extensions from this transverse passageway act to divert cool air through the rotor vanes. Abradable rings may be provided to the stator assemblies adjacent the spiral grooves which act to minimize wear between the sharp edges of the spiral grooves and the stator assemblies.

Abstract: A turbine blade having a bilaterally symmetrical side entry blade root for attaching the blade to a rotor of a steam turbine. The rotor has a longitudinal rotational axis of symmetry about which the blades rotate. The blades have a foil portion and a platform interposed between the foil portion and the blade roots. The roots are positionable in one of a plurality of complementary shaped grooves circumferentially disposed about the turbine rotor. The root is characterized by at least one pair of lugs symmetrically arranged on opposite sides of the root with each of the lugs having an outer bearing surface for reacting against a complementary opposed mating surface formed in each of the rotor grooves. The bearing surfaces on the lugs are aligned along an arc of a circle centered on the rotor rotational axis.

Abstract: A turbine rotor has composite ceramic blades each having a bulb-shaped root with planar flanks which define an angle of convergence between them not exceeding ten degrees, and by which the root is held in a dovetail section socket in the periphery of the rotor disc by means of wedge-shaped members also disposed in the socket on opposite sides of the root. Each wedge-shaped member is part of an element including a platform which is disposed adjacent the curved portion of the blade radially outwards of the socket and which is joined to the wedge-shaped member by an integral strut. The platforms of all of the elements extend in a circumferential direction and combine to define a continuous ring forming part of the inner boundary of the gas flow path through the turbine.

Abstract: A bladed turbine disk has a plurality of air cooled blades. The disk has a substantially continuous impervious rim. Each blade has a platform and an impervious base with the cooling air inlet between the platform and base. Each blade base is diffusion bonded to the rim, preferably to a slightly raised plateau. The edge of the bond surface is accessable and free of stress concentration.

Abstract: A steam turbine of the type employing a plurality of axial entry blades has a first annular plate juxtaposed one side of the disc that overlays the grooves in the disc and faces of the platforms of the blades. If desired, a second similar annular plate may be provided on the other side of the disc. The annular plates reduce windage and leakage.

Abstract: Two-part turbine-blade retainer structures are disclosed for axial retention of each of a plurality of turbine blades to a rotor wheel, wherein radial retention is via fir-tree engagement of individual blade roots to the wheel. In a preferred embodiment, a male or bolt element of the retainer has a shank which is characterized by a smoothly cylindrical portion adjacent at one end to one of the heads; this cylindrical portion terminates at a shoulder, beyond which the shank is reduced and externally threaded. A sleeve or nut element of the retainer has an elongate threaded bore and is characterized by an outer cylindrical surface which extends to the second head. The two elements are proportioned to be inserted through opposite ends of a passageway and to be screwed together into firm engagement at the shoulder (i.e., at a location intermediate the two heads), with the sleeve covering the threads of the male element and the heads preventing the turbine blade from axial motion with respect to the wheel.

Abstract: A steam turbine of the type employing axial entry blades is provided with a plurality of generally tangentially oriented slots in the rotor steeples. Resilient, deformable pins are driven into the slots under the blade platforms so as to urge the blade roots radially outward.

Abstract: A redundant locking system for the closing blades of a circular array of curved Christmas tree-shaped roots of side entry freestanding steam turbine blades which have registering holes in the platform of the closing blades and the blades adjacent to the closing blades which receive pins, the pins fit tightly into the through holes and loosely into the hole in the adjacent blade to lock the closing blades in place and allow each blade to vibrate independently.

Abstract: Structure for retaining rotor blades of a disk and blade assembly of a rotary machine is disclosed. A plurality of blade lugs extend from beneath the platform of each rotor blade into engagement with a corresponding plurality of disk slots. In a preferred form the disk slots are formed to a helical geometry across the periphery of the disk.

Abstract: A sheet metal seal (42) provides both radial and axial sealing of the gap (34) formed between adjacent blade platforms (30, 32) in a rotor assembly (10) of a turbomachine.

Abstract: A rotor assembly comprising a disk, blade, and seal is disclosed. The disk has a circumferential blade retaining slot disposed therein. The blade includes an airfoil and root separated by a platform so that the root is mountable within the slot and the platform extends beyond the root to first and second opposite ends. The seal generally contacts the slot and platform and extends circumferentially from the root to the first end.

Abstract: A turbomachine rotor disc assembly includes a rotor disc having a plurality of blade-root grooves in its periphery, each two adjacent grooves defining a lobe lug between them. Rotor blades each include an aerofoil portion, a root portion, a platform defining the radially inner boundary of the aerofoil portion, and a stilt portion interconnecting the radially inner face of the platform and the root portion, a free space being defined between each adjacent pair of blades. The angular clearance of each blade in its groove is limited by wedges operative between adjacent blades on the stilts thereof and connecting members carrying the wedges secured to the rotor disc and capable of transmitting shock loads and distributing resultant forces over an adjacent sector of the rotor. The wedges are so dimensioned in relation to the dimensions of the stilts of adjacent blades that the angular clearance is limited to the permissible angular clearance of each blade during auto-rotation of the rotor.

Abstract: A side entry rotatable control stage blade with a wedge shape trailing edge support on the root portion which is formed to have two generally right trapezoidal surfaces which converge and a notch disposed on the opposite side of the platform with a trapezoidal surface which registers with one of the trapezoidal surfaces on the trailing edge support of the adjacent blade when the blades are disposed in a circular array in a steam turbine.

Abstract: A locking system for attaching a circular array of side entry steam turbine blades to a rotor disc utilizing a circumferential groove in the outer periphery of the disc and a notch in one side of a blade platform to form an opening for receiving a pin which prevents the blade from sliding in the side entry slots in the disc and the next blade installed on the rotor captures a pin in the preceding blade except the last blade assembled in the array or closing blade has a kerf in the platform which registers with the circumferential groove in the disc and a locking key fitting into the kerf and groove to hold the last blade in place and the locking key being captured in the kerf and groove by a strip of metal passing through a slit in the locking key and an opening formed in the platforms.