JPH1047004A - Rotor blade of rotary fluid machinery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate relative slide between a hollow groove and a damper, and suppress growth of vibration caused by damping action by friction between them by arranging the hollow groove in a blade, and inserting the damper capable of sliding relatively with the hollow groove in the hollow groove. SOLUTION: A plurality of holes 3 which are formed in parallel with each other extending to a blade longitudinal direction are opened on a blade part 1 from the lower part of a blade root 2, and a plurality of hollow grooves are arranged in a blade. A pin 4 having the same diameter as the hole 3 which is enabled relative sliding with the hollow grooves and a plurality of small diameter pins 5 which are brought into contact with the hollow grooves are inserted into respective hollow grooves. When vibration is generated on a rotor blade, sliding is generated between a plurality of hollow grooves arranged in the blade and pin 4 or a plurality of small diameter pins 5, the pin 4 or the plurality of small diameter pins 5 are acted together with a damper. It is thus possible to effectively suppress growth of vibration of the rotor blade by damping action caused by friction between them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving blade of a rotary fluid machine such as a compressor, a gas turbine, and a steam turbine.

[0002]

2. Description of the Related Art As shown in FIG. 4, a conventional compressor blade adopts a structure in which a blade root 2 on which a blade portion 1 is erected is inserted into a blade groove of a rotor (not shown). For this,
Structural damping (friction damping) can be obtained only at the blade root of the rotor blade. However, since the relative slip between the blade root and the blade groove generated when the blade vibrates is very small, large structural damping cannot be expected.

[0003]

Since the conventional compressor rotor blade has a small structural damping as described above, a large vibration is generated by the excitation force generated by the turbulence of the flow in the surge region passing during the start-up acceleration. . This vibration may cause the blade to break.

In a constant-speed rotating machine, when the rotor blades resonate during rated rotation, large vibrations are generated and the rotor blades may be damaged.

An object of the present invention is to provide a moving blade of a rotary fluid machine such as a compressor which can solve the above problems.

[0006]

A rotor blade of a rotary fluid machine according to the present invention has a hollow groove provided inside the blade, and a damper capable of sliding relative to the hollow groove is inserted into the hollow groove. It is characterized by.

In the present invention, when vibration occurs in the rotor blade, relative slip occurs between the hollow groove provided inside the blade and the damper inserted in the hollow groove, and the damping action due to friction between the two. Thereby, the growth of vibration can be suppressed.

In a conventional rotating fluid rotor blade, the vibration amplitude of the blade with respect to the rotation speed of the rotor is shown by a dotted line in FIG. 5, but in the present invention, the vibration amplitude of the blade with respect to the rotation speed of the rotor is plotted. 5, the solid line indicates that the present invention effectively suppresses the growth of vibration.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention relating to a moving blade of a compressor will be described with reference to FIG. Wing root 2
A plurality of holes 3 extending in the wing length (wing height) direction from the lower side in the wing portion 1 are provided in the wing, and a plurality of hollow grooves are formed in the wing, and a plurality of hollow grooves are provided inside the wing. A pin 4 (see FIG. 1 (c)) having substantially the same diameter as the hole 3 capable of relative sliding and a plurality of small-diameter pins 5 in contact with the hollow groove are inserted. As described above, after the pin 4 or the plurality of small diameter pins 5 are inserted into the hollow groove, the blade root 2 is inserted into the blade groove of the rotor (not shown).

In this embodiment, when vibration occurs in the moving blade, a slip occurs between the plurality of hollow grooves provided inside the blade and the pin 4 or the plurality of small-diameter pins 5, causing the pin 4 or the plurality of small-diameter pins to slip. The pin 5 works with a damper, and the growth of vibration of the rotor blade can be effectively suppressed by a damping action due to friction between the two.

A second embodiment of the present invention relating to a moving blade of a compressor will be described with reference to FIG. In the present embodiment, one hollow groove 6 is provided inside the blade by making one long rectangular hole 6 extending in the blade length (blade height) direction from the lower side of the blade root 2 in the blade portion 1. Inside the hollow groove, a thin laminated plate 7 having substantially the same cross section as the hole 6 capable of sliding relative to the hollow groove was inserted.

Also in the present embodiment, when vibration occurs in the rotor blades, a slip occurs between the hollow groove provided inside the blade and the laminated plate 7, and the laminated plate 7 acts as a damper. The growth of vibration of the rotor blade can be effectively suppressed by the damping action due to friction.

A third embodiment of the present invention will be described with reference to FIG. This embodiment is a first embodiment of the present invention.
And on the surface of the pin 4 or the laminate 7 in the second embodiment,
Knurled 8 and 9 respectively, pin 4
Alternatively, it is possible to further increase the frictional force applied to the relative slip between the laminated plate 7 and the hollow groove provided inside the blade, whereby it is possible to reliably suppress the growth of the vibration of the blade. it can.

[0014]

In the rotating blade of the rotary fluid machine of the present invention, a hollow groove is provided inside the blade and a damper capable of sliding relative to the hollow groove is inserted into the hollow groove. Can increase the structural damping. This makes it difficult for the rotor blades to generate vibration, thereby improving reliability.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention, and FIG.
FIG. 1B is a perspective view showing the blade root portion, and FIGS. 1C and 1D are perspective views of a pin and a plurality of small diameter pins used in the embodiment. FIG.

FIG. 2 shows a second embodiment of the present invention, and FIG.
FIG. 2B is a perspective view showing the blade root portion, and FIG. 2C is a perspective view of a laminate used in the embodiment.

FIGS. 3 (a) and 3 (b) are perspective views of a pin and a laminate used in a third embodiment of the present invention, respectively.

FIG. 4 is a perspective view of a conventional compressor blade.

FIG. 5 is a graph showing the relationship between the rotational speed of the rotor and the vibration amplitude of the blade in the compressor rotor blade of the present invention and the conventional compressor rotor blade.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wing part 2 Wing root 3 hole 4 pin 5 Small diameter pin 6 hole 7 Laminated plate 8, 9 Knurling

Claims (1)

[Claims] 1. A rotating blade of a rotary fluid machine, wherein a hollow groove is provided inside a blade, and a damper capable of sliding relative to the hollow groove is inserted into the hollow groove.