JPH09287404A - Rotating machine moving blade such as steam turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent movement of a blade in rotating discharge abrasion powder accumulated on a bearing, and release stress concentration to a corner R part by arranging corner groove extending along the corner R part of the blade root bearing surface of moving blade having a T-shaped blade root and communicating with the end part of a surface groove. SOLUTION: A corner groove 6 is arranged on the corner R part of a T-shaped blade root 3, and also surface grooves 5 inclined in a rotational direction and formed in an arrow shape are arranged on a bearing surface 4, and the end part of the surface groove 5 communicates with the corner groove 6. Joining of a blade root supporting surface which abuts on the bearing surface 4 is strengthened by the surface grooves 5 having a plurality of bands so as to prevent movement of a blade 1 on operating. Abrasion powder is discharged and eliminated through the surface groove 5 and the corner groove 6 so as to prevent promotion of fretting. Thus, it is also possible to release stress concentration in the corner R part by the corner groove 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor blade applied to rotary machines such as steam turbines, gas turbines, gas turbine compressors.

[0002]

2. Description of the Related Art A conventional high-pressure steam turbine rotor blade has a shape shown in a perspective view in FIG. 4 and a front view in FIG.

That is, the bearing surface 4 is a flat surface without any processing. Moreover, since the shroud 2 on the top of the blade 1 is independent for each blade 1,
Each has a structure that can move independently.

Therefore, when the blade 1 vibrates, the load is supported only on the bearing surface 4, and even if abrasion powder is generated on the bearing surface 4, it is difficult to discharge it, and thus the flatting is promoted. become.

As for the entire turbine, FIG.
As shown in FIG. 7, during operation of the turbine, the blade 1 inserted in the blade groove 9 of the rotor disk 8 receives a force in the direction of jumping out from the blade groove 9 due to the centrifugal force due to the rotation, and the bearing of the blade root 3 The surface 4 is structured to receive a large centrifugal load.

As a vibration preventing measure at this time, Japanese Patent Laid-Open No. Sho 62-62
There is known a structure in which a damper piece is inserted between the wings of each other like -17306. See also Kai 61-255
There is also known a structure in which a superplastic alloy is embedded between the blade root and the blade of the rotor disk as shown in FIG. Under the same idea, there is also known a structure in which a protrusion is projected from the blade root of a moving blade and brought into contact with a rotor disk, as in Japanese Utility Model Laid-Open No. Sho 63-168201.

As described above, in the conventional turbine, although various measures have been taken with respect to the vibration problem, there is still no example in which the movement of the blade during operation is suppressed and the stress is also reduced. The reality is that there is none.

[0008]

As described above, the turbine rotor blade having the T-shaped blade root is inserted into the blade groove 9 formed in the outer periphery of the turbine rotor disk 7 shown in FIG. A method of fixing the final insertion blade 11 with a screw or the like is adopted. FIG. 7 is a sectional view showing a state in which all the wings are inserted, and FIG. 8 is a diagram showing a quarter of the entire circumference.
It is.

When the turbine rotor rotates, the final insertion blade 11 is fixed to the rotor disk 8 with screws or the like so that it cannot move, but the other blades can move in the circumferential direction, so Adjacent blades 12 of the insertion blades 11 (the blades inserted first) are moved to move the gap 1 between the shrouds 2 to each other.
There may be an event of expanding or narrowing 3.

This phenomenon is an undesired factor because it causes an unstable factor in the operation of the turbine. Further, due to the above-mentioned phenomenon and the like, the blade root 3 and the bearing surface 4 may be worn due to vibration of the blade during operation.

If the abrasion powder generated at this time remains on the contact surface, fretting will be promoted, so it is important to discharge this abrasion powder. Further, the corner portion 7 of the bearing surface 4 in the blade root 3 is a high pressure portion, and it is also necessary to relieve the stress in this portion.

It is an object of the present invention to solve these various problems and to provide a moving blade capable of stable operation.

[0013]

The present invention has been made to solve the above-mentioned problems, and a plurality of surface grooves having a shape inclined with respect to the rotation direction are formed on a blade root bearing surface of a moving blade having a T-shaped blade root. Provided is a rotary machine moving blade such as a steam turbine having a groove provided with a groove and extending along a corner R portion of the blade root bearing surface and communicating with an end of the surface groove, and a rotation direction provided on the bearing surface. With respect to the inclined surface, a plurality of surface grooves form a strong connection with the blade root support surface that abuts the bearing surface to prevent the blade from moving during operation, and the same surface groove and the corners communicating with it. The abrasion powder is removed through the groove to prevent the fretting from being promoted, and the corner groove reduces the stress concentration at the corner R portion.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. It should be noted that the same parts as those of the conventional one described above are denoted by the same reference numerals in the drawings, and overlapping description will be omitted.

A corner groove 6 is provided in the corner R portion 7 of the blade root 3, and a bearing groove 4 is provided in the bearing surface 4 in the shape of an arrow that is inclined with respect to the rotation direction. It communicates with the corner groove 6.

The shape of the corner groove 6 and the surface groove 5 will be described in more detail. The corner groove 6 is preferably 2 to 5 mmR, the surface groove 5 has a depth of 0.5 to 3 mm, and the width is the same as the depth. Something is preferable.

The planar shape of the surface groove 5 is preferably an arrow shape inclined with respect to the rotating direction 14 of the turbine as clearly shown in FIG. The shape is not limited to the arrow shape, but may be a V shape, a W shape, a Z shape, or the like.
In any case, it is preferable to have a portion that is inclined with respect to the turbine rotation direction 14.

Now, during operation of the turbine, the blade 1 is rotated in the direction of arrow 14 by the steam force. In this state, the blade 1 is vibrated by the steam force, and the bearing surface 4 of the blade root 3 supporting the blade 1 is worn.

However, the wear debris is discharged by the bearing surface groove 5 provided on the bearing surface 4, and the inner corner R
By installing the corner groove 6 also in the portion 7 and connecting the two with each other, the abrasion powder can be easily discharged.

Although the corner R portion 7 is a high stress portion due to centrifugal force, the corner groove 6 can be provided in this portion to have an effect of relaxing stress concentration. Further, by making the shape of the bearing surface groove 5 an arrow shape in the rotation direction 14, it is possible to have an effect of preventing the movement of the blade during operation.

That is, since the turbine rotor blades 1 rotate at a high speed, a large rotational centrifugal force is generated, and even a small blade has 5
The reaction force of about 50 Ton is supported by the blade root 3.
Therefore, the blade groove rotor side also receives a depression of about 1/1000 mm, and the surface groove 5 of the blade root bearing surface 4 can effectively prevent the blade from moving during operation.

Although the present invention has been described with reference to the illustrated embodiment, the present invention is not limited to such an embodiment.
It goes without saying that various modifications may be made to the specific structure within the scope of the present invention.

[0023]

As described above, according to the present invention, the moving blades are prevented from moving during rotation, and the stress concentration on the corner R portion is alleviated.
In addition, it is possible to prevent the abrasion powder from remaining on the bearing surface and prevent the fretting from being accelerated. As a result, it was possible to obtain a rotary machine such as a steam turbine that stably operates.

[Brief description of drawings]

FIG. 1 is a perspective view of a steam turbine rotor blade according to an embodiment of the present invention.

FIG. 2 is a front view of a root portion of the moving blade of FIG.

FIG. 3 is a top view of a bearing surface in the blade root portion of FIG.

FIG. 4 is a perspective view of a conventional steam turbine blade.

5 is a front view of the moving blade of FIG.

FIG. 6 is an explanatory view showing blade grooves of a turbine rotor disk into which a T-shaped blade root is implanted.

FIG. 7 is an explanatory view showing a rotor to which a moving blade is attached.

FIG. 8 is an explanatory view showing a state in which a wing is implanted over the entire circumference.

[Explanation of symbols]

 1 Blade 2 Shroud 3 Blade Root 4 Bearing Surface 5 Surface Groove 6 Corner Groove 8 Disc 9 Blade Groove

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[Procedure amendment]

[Submission date] July 18, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

[0008]

As described above, the turbine blade having the T-shaped blade root has the insertion hole 10 formed in the blade groove 9 formed in the outer periphery of the turbine rotor disk 7 shown in FIG. A method is used in which the blades are inserted in order and the final insertion blade 11 is fixed with a screw or the like. FIG. 7 shows a state in which all the blades are inserted in a sectional view, and FIG. 8 shows a quarter of the entire circumference.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

When the turbine rotor rotates, the final insertion blade 11 is fixed to the rotor disk 8 with screws or the like so that it cannot move, but the other blades can move in the circumferential direction, so Adjacent blades 12 of the insertion blades 11 (the blades inserted first) are moved to move the gap 1 between the shrouds 2 to each other.
Considering the possibility of causing an event of expanding or narrowing 3
Can be obtained .

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

[0010] preferred in on this event to perform the operation of the turbine
It is also possible that a phenomenon in which the blade root 3 and the bearing surface 4 are worn due to vibration of the blade during operation may occur due to the above-mentioned phenomenon or the like.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

If the abrasion powder generated at this time remains on the contact surface, fretting will be promoted, so it is important to discharge this abrasion powder. Further, the corner portion 7 of the bearing surface 4 in the blade root 3 is a high stress portion , and it is also necessary to relax the stress in this portion.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

[0013]

The present invention has been made to solve the above problems, and a plurality of surface grooves having a shape inclined with respect to the rotation direction are formed on a blade root bearing surface of a moving blade having a T-shaped blade root. Provided is a rotary machine moving blade such as a steam turbine having a groove provided with a groove and extending along a corner R portion of the blade root bearing surface and communicating with an end of the surface groove, and a rotation direction provided on the bearing surface. With respect to the inclined surface, a plurality of surface grooves form a strong connection with the blade root support surface that abuts the bearing surface to prevent the blade from moving during operation, and the same surface groove and the corners communicating with it. The abrasion powder is removed through the groove to prevent the fretting from being promoted, and the corner groove reduces the stress concentration at the corner R portion.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] Fig. 6

[Correction method] Change

[Correction contents]

FIG. 6 is an explanatory view showing blade grooves of a turbine rotor disk into which T-shaped blade roots are implanted.

[Procedure amendment 8]

[Document name to be amended] Drawing

[Correction target item name] Fig. 8

[Correction method] Change

[Correction contents]

[Figure 8]

Claims (1)

[Claims] 1. A blade root bearing surface of a rotor blade having a T-shaped blade root is provided with a plurality of surface grooves having a shape inclined with respect to the rotation direction, and extends along a corner R of the blade root bearing surface. A rotary machine rotor blade for a steam turbine or the like, which is provided with a corner groove communicating with an end of the surface groove.