JPS5848729B2 - Moving blade fixing mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to turbomachines, and more particularly to an improved means for axially securing rotor blades in the rotor or disk of a turbomachine.

The blade securing means previously proposed for axially securing a rotor blade within a generally axially extending lotus rotor or disk slot typically include members such as:
It includes a member extending axially across the disk proximate the rotor blade root.

Many of these securing devices include one or more tabs that are bent after assembly to help secure the rotor blade axially within the rotor rotor.

However, such a structure is not preferable.

This is because the axial force required to secure the rotor blade within the slot is counteracted by members bent during assembly.

In addition, bent tabs typically have some residual strain that can result in springback of the bent tab and axial loosening of the rotor blade.

Other conventional solutions use spacers and retaining clips.

In this case, the tabs bent during assembly only restrain the spacer.

Although this solution overcomes the problem of axial reaction forces on the rotor blades through bent tabs during assembly and the problem of springback in the tabs, it is important to note that two issues exist: Requires access to one side and bending one tab during assembly to retain the spacer.

Another solution for axially fixing the turbine rotor blades is the 195
No. 2,867,408, issued Jan. 6, 1999.

In this case, a locking key is used which is fitted into the rotor slot and platform slot.

However, in order to secure the blade row using the structure disclosed in the above-identified patent, the last key must be peened to fill the slot formed in the adjacent blade platform.

Furthermore, in such a construction, removal and replacement of one blade would require removal of all blades.

The main object of the invention is therefore to allow movement to be fixed to the disk without requiring tab bending during assembly, without accessing either side of the disk, and to allow removal and replacement of a single rotor blade. An object of the present invention is to provide a rotor blade fixing means that enables the following.

SUMMARY OF THE INVENTION The present invention provides a locking key that includes a rectangular block portion and a generally cylindrical stem projecting therefrom.

A keyway is formed in the plant platform portion of the turbomachine rotor blade to receive a locking key from the underside of the platform.

The block portion fits within the slot and the stem passes through an opening formed in the platform.

A key groove is formed on the outer peripheral surface of the disk at a position below the keyway of the platform.

The block portion of the key has a length dimension that is greater than its width dimension.

The axial length of the platform slot is defined to correspond to the relatively small width dimension of the locking key block, while the axial length of the key groove in the disc is configured to correspond to the relatively long length dimension of the locking key block. determined.

In this way, the locking key can be dropped radially into the key groove in the disk, and the locking key can be rotated 90 DEG to axially secure the rotor blade to the disk.

By providing suitable means, such as a screwdriver, at the distal end of the lock key stem, it is possible to turn the lock key into and out of its fixed position.

Also, during operation of the winged disc of the turbomachine, the locking stem may be locked to the platform by protruding means or other suitable means to prevent the locking key from rotating out of its fixed position.

Next, in order to further clarify the present invention, embodiments of the present invention will be described with reference to the accompanying drawings.

In the drawings, and in particular in FIG. 1, a winged rotor or disk of a turbomachine is designated generally at 10.

It consists of a rotatable annular disk 12 supporting a plurality of radially extending vanes 14 on its outer periphery.

The moving blade 14 has an airfoil section 16, a platform section 18, and a root section 2.
Contains 0.

Disk 12 has a slot 22 for each rotor blade that extends generally axially across disk 12 at the outer circumference of disk 12 .

Slot 22 is cooperatively formed with root 20 to axially receive root 20 and secure rotor blade 14 radially to disk 12 against centrifugal forces.

As shown in FIG. 1, the blade platform 18 extends on the outer peripheral surface 23 of the disk 12 so as to form the inner boundary of fluid flow across the airfoil 16.

The means of the present invention for axially securing the blade root 20 within the disc throat 22 includes a locking key 24 and associated keyways 26,28.

A keyway 26 is formed in the blade platform 18 and a keyway 28 is formed in the outer peripheral surface 23 of the disk 12.

In FIG. 2, locking key 24 includes a block portion 30 and a stem portion 32. As shown in FIG.

Flock portion 30 is generally rectangular and has a radial length t, a width W, and a length l.

Stem portion 32 is preferably cylindrical and projects perpendicularly from a central portion of the radially outwardly facing surface of flock 300.

The radially outer end 34 of the stem 32 is formed with a screwdriver slot or other suitable means 35, thus allowing the key 24 to be turned to its locked position as described below.

3, 4, and 5, the platform keyway 26 includes a slot 36 formed radially inwardly of the platform 18 and an opening 38 communicating with the slot and extending radially through the blade platform 18. include.

Platform slot 36, as shown in FIG.
The axial width W is determined to accommodate the width dimension W of the stop keep lock 30, and the radial width W is determined to accommodate the thickness dimension t of the key block 30 so as to be in a non-interfering relationship with the disk outer circumference 23. It's tall.

The stem portion 32 has a keyway opening 38 as shown in FIG.
penetrate.

The disk keyway 28 is in the form of a circumferential slot having an axial length L and a radial height T, as shown in FIG. It corresponds to the length dimension l and the thickness dimension t.

The circumferential slot 28 is in an axial position such that when the blade root 20 of the blade 814 is inserted into the disk slot 22, the slot 28 mates with the keyway 26 formed in the blade plant home 18.

The uses and functions of the present invention are as follows.

The locking key 24 is inserted into the platform keyway 26 as shown in FIGS. 4 and 6.

At this time, the flock part 30 is inserted into the platform slot 36
and the stem portion 32 is inserted into the plant home opening 3.
Penetrate 8.

Next, the rotor blades 14 are each inserted into the rotor rotor 22.

When the stop key 24 is dropped radially inward with the blade 14 positioned within the rotor slot 22 as shown in FIG. 4, the block portion 30 engages the keyway 28 of the disk.

Next, use the 1,000-stage slot 35 to set the stop key 24 to the 6th and 8th positions.
Rotate 90 degrees from the released position shown in Figures 5 and 9 to the locked position.

In this fixed position, the length l of the block 30 points in the axial direction.

The opposite corner of block 300 is rotated to a second position to allow key 24 to be turned 90 degrees into fixed engagement with slot 28
, 6 and 8, as indicated by reference numeral 40.

Since the axial length W of the platform slot 36 is smaller than the axial length L of the disk slot 28, the stop key 24 is moved by the abutment between the radially outer surface of the block 300 and the radially inner surface of the rotor blade platform 18. It is restrained radially in the fixed position of FIGS. 3, 5 and 9.

At the same time, the stop key stem 32 and the platform opening 38
The axial movement of the rotor blade is prevented by the contact with the wall surface and the contact between the block 30 and the disk slot 28.

As clearly shown in FIGS. 1 and 3, the stem 32 has the following 5 tr dimensions for aerodynamic reasons, i.e., the radially outer end of the stem when the locking key 24 is in a fixed position within the disc slot 28. Preferably, 34 is dimensioned such that it is generally coplanar with the exterior surface of plant home 18.

In order to prevent the stop key 24 from rotating from the fixed position shown in FIGS. 5 and 9 to the released position shown in FIGS. may be locked by protruding means or other suitable means.

To facilitate such engagement, platform 18
A suitable slot 42 may be provided adjacent the keyway opening 38.

When locked, the slots 35 of the stem 32 are perpendicular to the slots 42, thus securely securing the turbine blades 14 to the disk 12.

To remove the rotor blades from disk 12, the above steps can be followed in reverse.

The locking key 24 is rotated to its released position shown in FIG. 8 and moved radially outwardly away from the disc slot 28 and into the platform slot 36 of the keyway 26.

The turbine drive R14 is then slid axially out of the tabtail slot 22 of the disk.

Alternatively, and based on the relative dimensions and strengths of stem portion 32 and blade platform 18, stem portion 32 is sheared from block portion 30 by delivering a sharp blow to the axial surface of blade root portion 20.

As can be seen from the foregoing description, the present invention is directed to a turbomachinery system that allows for the removal and replacement of a single rotor blade without requiring tab bending during assembly and without disturbing adjacent rotor blades. Provides a means for axially securing the rotor blade to the disk.

Although the preferred embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications can be made without departing from the basic concept of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a partial perspective view showing a bladed disk of an exemplary turbomachine using the rotor blade fixing means of the present invention, FIG. 2 is an enlarged perspective view showing the stop key of the present invention, and FIG. 1, and FIG. 4 is a view similar to FIG. 3, showing that the stop key of FIG. 2 allows the rotor blade to be inserted into its associated disc slot. Indicates the case in position. FIG. 5 is an enlarged fragmentary plan view taken along line 5--5 of FIG. 3, showing the locking key of FIG. 2 in its locked position. FIG. 6 is a view similar to FIG. 5 along line 6--6 of FIG. 4, showing the lock key of FIG. 2 in its released position. FIG. 7 is a view similar to FIG. 1, but showing the rotor blade removed from its disk slot. FIG. 8 is an enlarged fragmentary cross-sectional view taken along line 8--8 of FIG. 4, showing the lock key of FIG. 2 in its released position. FIG. 9 is a view taken along line 9--9 of FIG. 3 and shows the lock key of FIG. 2 in its locked position. In the figure, 24 is a stop key, 26 and 28 are keyways, 30 is a block portion, 32 is a stem portion, 34 is a stem tip, 35 is a screwdriver groove, 36 is a platform slot, 38 is a radial opening, and 40 is a block. Represents the shaping corner of the section.

Claims (1)

[Claims] 1 at least one slot extending generally axially of the rotating disk is formed in an outer circumferential surface of the rotating disk, projecting generally radially from the disk a rotor blade having a root portion fitted into the axial slot; and a plant home portion covering a portion of the outer peripheral surface of the disk, the axial slot and the root portion abutting each other and radially fixing the rotor blade to the disk against centrifugal force. A device for axially fixing the root of a rotor blade in an axial slot of a disk in a turbomachinery of a type having the same size and shape, the retaining key being an elongated block projecting from the block and terminating in a tip. a stem portion; the block portion has a thickness defined by a radially inward surface and a radially outward surface; a certain width; and a length greater than the width; projecting perpendicularly from a central portion of a radially outwardly facing surface of said platform portion having a circumferentially extending slot radially inwardly thereof; a radial opening is formed therethrough having an axial width sized to receive a width dimension of the platform portion and a radial height sized to receive the block in a non-interfering relationship with the disk; An aperture connects with a slot in the plant platform portion to receive the stem portion in close mating relationship with the stem portion when the block portion engages the slot in the platform portion, and an opening connects with the slot in the platform portion to receive the stem portion in close mating relationship with the stem portion when the block portion engages the slot in the platform portion. A circumferential slot is formed in the surface adjacent the axial slot, the circumferential slot of the disc having an axial length sized to accommodate the length dimension of the block in close-fitting relationship with the slot. and when the rotor blade is inserted into the axial slot of the disk,
said stop block portion disengaging from engagement with said platform slot and falling radially to engage a circumferential slot of said disk and then axially securing said blade to said disk axial slot; the circumferential slot of the disk having a position and a radial force depth such that the block portion can be rotated;