JP3140307B2 - Rotating body evaluation jig - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed rotation of a ceramic rotating body part such as a moving blade made of ceramics incorporated in a large axial type rotor or a radial type rotor which is applied to a gas turbine, a steam turbine or the like. The present invention relates to a jig for evaluating a rotating body used for a guarantee test or a destructive test.

[0002]

2. Description of the Related Art In recent years, ultra-precision rotating bodies in various industrial machinery and rotating parts used in high-temperature atmospheres have low thermal expansion, high mechanical strength, and excellent heat resistance and wear resistance. In addition, oxide ceramic sinters such as alumina (Al ₂ O ₃ ) and zirconia (ZrO ₂ ), which have the characteristic of being light in weight because of their low specific gravity, silicon nitride (Si ₃ N ₄ ), Sialon and silicon carbide (Si
Various studies and proposals have been made to use non-oxide ceramic sintered bodies such as C).

In general, a rotating body composed of ceramic parts made of the above various ceramic sintered bodies, for example, an axial type or radial type rotor used for a gas turbine, a steam turbine or the like, is in operation with a metal rotor. Similarly, it rotates at a high speed of several hundred thousand to several hundred thousand rotations per minute.

Therefore, in order to evaluate and ascertain whether or not the ceramic rotating body part has a performance equal to or higher than a certain level, various types of non-destructive inspections such as X-ray radiography and the like are carried out. The reliability test is performed by assembling the parts into the evaluation jig and actually performing a high-speed rotation test on all the products, and by performing a high-speed rotation destruction test until failure to clarify the limit performance. We are trying to secure.

In such a guarantee test or a destructive test, a metal shaft is shrink-fitted or pressed into a metal disk or hub.
Using a screw jig or a jig for evaluation having a structure fixed by an adhesive, etc., after incorporating a ceramic rotating body part to be evaluated into a locking portion provided on a circumferential surface of the jig for evaluation,
The test was performed by correcting the balance of the rotating body for evaluation and attaching it to a high-speed rotating test machine (see Japanese Patent Publication No. 2-20801).

[0006]

However, the above-mentioned fixing structure is considered to be applicable to a radial type rotor such as a small axial type rotor or a turbocharger, but a gas turbine or a gas turbine having a maximum outer diameter exceeding 100 mm. For rotating bodies such as large axial rotors and radial rotors used in steam turbines,
For example, as shown in FIG. 4 showing an evaluation jig before incorporating a ceramic rotary member, a metal disk 13 fixed to a shaft 11 for mounting on a high-speed rotation tester (not shown) with a nut 12 is provided. Because of the influence of the centrifugal force, the shaft 11 spreads at the joint portion 14 with the shaft 11 and the fixing of the shaft 11 is loosened, causing imbalance and easy vibration at high speed rotation. There was a problem that it was not possible and the reliability was poor.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and has as its object to mount the apparatus on a high-speed rotation tester even if a large centrifugal force is applied to a metal disk or hub during a high-speed rotation test. The connection between the disk and the hub for fixing the shaft is not widened, and the fixing of the shaft is not loosened and unbalanced.
A highly reliable rotating body evaluation jig that does not generate vibrations up to the high rotation speeds described above and can accurately evaluate the guarantee test and destruction test of rotating bodies such as large axial rotors and radial rotors. It will not be provided.

[0008]

A jig for evaluating a rotating body according to the present invention has a maximum outer diameter D of a metal disk or hub constituting the rotating body and a diameter d _{1 of} a convex portion provided at the center thereof. Then, a convex portion satisfying a relationship of d ₁ / D of 0.1 to 0.4 is shrink-fitted into a concave portion provided on a shaft for mounting the rotating body on a high-speed rotation tester, and further provided on the shaft. was through in the longitudinal direction of the shaft of the step portion, up to the disk or hub, a plurality of screw holes having a center on a circumference the diameter at the shaft concentrically is d ₂ at equal intervals, d _A bolt is screwed into a screw hole satisfying a relationship of ₂ / D of 0.5 or less, and the shaft and the disk or hub are fastened.

Alternatively, assuming that the maximum outer diameter of a metal disk or hub constituting the rotating body is D and the diameter of a through hole provided at the center is d ₃ , d ₃ / D is 0.1-0. A shaft for attaching the rotating body to a high-speed rotation tester is shrink-fitted into a through hole satisfying the relationship of 4, and further penetrates a step provided on the shaft, and is inserted into the disk or hub in the longitudinal direction of the shaft. screw up, a plurality of screw holes having a center on a circumference the diameter at the shaft concentrically is d ₄ at equal intervals, the bolt into the screw hole relationship is 0.5 or less of d ₄ / D leads And the shaft or disk or hub is fastened.

In the present invention, if the relation d ₁ / D between the maximum outer diameter of the metal disk or hub constituting the rotating body and the diameter of the convex portion provided at the center of the disk becomes less than 0.1, the burning during the high-speed rotation test is performed. It is not preferable because an excessive torsional stress is generated in the fitted convex portion and the balance tends to be lost, and the built-in ceramic rotating body component may be broken.

On the other hand, when d ₁ / D exceeds 0.4,
Since an extremely large stress is applied to the screwed bolt, the strength of the bolt is exceeded, and there is a high possibility that the bolt will be broken below the neck of the bolt, so that the d ₁ / D is limited to the range of 0.1 to 0.4. In particular, the range of 0.1 to 0.3 is preferable.

When the relationship d ₂ / D between the screw hole and the maximum outer diameter of the disk or hub exceeds 0.5, a large stress exceeding the strength of the bolt is applied to the screwed bolt, and the bolt has a large diameter. It is not desirable because the shaft corresponding to the tip of the protruding portion that is broken from below the neck or shrink-fitted is deformed and loses balance.

Further, when the relation of d ₃ / D in the present invention is less than 0.1, an excessive torsional stress is generated in the shrink-fitted shaft at the time of a high-speed rotation test, the balance is lost, and the built-in ceramic rotation is performed. If the relation d ₃ / D exceeds 0.4, the tensile stress generated by the centrifugal force becomes excessive, and the disk or hub itself may be damaged. .

Therefore, the relation of d ₃ / D is 0.1 to
It is limited to the range of 0.4, and it is particularly desirable to satisfy 0.2 to 0.4.

[0015]

According to the jig for evaluating a rotating body of the present invention, a concave portion of a shaft for attaching a rotating body to a high-speed rotation tester is inserted into a convex portion of the disk or hub, or the shaft is inserted through a disk or hub of the rotating body. Each of the discs or the hub is screwed through a stepped portion provided in the shaft in the longitudinal direction of the shaft and fastened to the outer peripheral direction of the joint portion between the disc or the hub and the shaft. The stress to be spread out is suppressed by the anchor effect of the bolt, and the effect of the centrifugal force generated at high speed rotation is prevented.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a jig for evaluating a rotating body of the present invention will be described.
This will be described in detail with reference to the drawings.

FIG. 1 is a perspective view of a jig for evaluating a rotating body composed of a disk having a groove for incorporating a ceramic rotating body part and a shaft to be mounted on a high-speed rotation tester (not shown).

FIGS. 2 and 3 are cross-sectional views of a jig for evaluating a rotating body in which a disk and a shaft are shrink-fitted, and both are fastened with bolts.

1 to 3, reference numeral 1 denotes a convex portion 4 provided at the center of a disk 2 having a groove 10 for incorporating a ceramic rotary member (not shown), on a step portion 7 side of a shaft 3. After the recess 5 formed at the end is shrink-fitted, or the shaft 3 is shrink-fitted into the through hole 6 provided at the center of the disc 2, and then the stepped portion 7 provided on the shaft 3 is further formed.
This is a rotating body evaluation jig in which bolts 9 are screwed and fastened to a plurality of screw holes 8 drilled at equal intervals up to the disk 2 in the longitudinal direction of the shaft 3 through the shaft 3.

In the jig for evaluating a rotating body of the present invention, the screw holes 8 are desirably provided at at least 4 to 8 places at equal intervals, and from the viewpoint of the amount of run-out as the rotating body, the maximum number of rotations, and the balance correction. Is preferably 4 to 6 places.

(Embodiment 1) As shown in the sectional view of FIG.
An outer diameter of 100 mm having a protrusion at the center with a length of 15 mm and a diameter of 12 mm, with various dimensions of the diameter,
On a disc made of Ni-base alloy steel with a maximum thickness of 20 mm,
A steel type having a recess formed by setting the shrink fitting allowance at the difference in inner and outer diameters to 20 μm and made of SCM435 is 20 mm in diameter.
Was subjected to a shrink fitting temperature of 300 ° C. and shrink-fitted integrally.

Next, bolts were screwed into screw holes provided at four positions evenly at various positions where d ₂ / D was variously set up to the disk through the step portion of the shaft to fasten the disk to the shaft.

In the jig for evaluating the rotating body thus obtained, the blade of the rotating body made of ceramic made of a silicon nitride sintered body is incorporated into the groove of the disk, and after correcting the balance,
A high-speed rotation test was carried out at room temperature with a maximum number of revolutions of 85,000 revolutions per minute set in a cold spin tester.

In the high-speed rotation test, the maximum deflection of the spindle during the high-speed rotation is measured to evaluate the vibration, the change in the amount of unbalance before and after the high-speed rotation test, and the coaxiality at the tip of the shaft on the step portion side are directly measured. The change in the angle was measured, and the jig for evaluating the rotating body was evaluated. However, if the run-out of the spindle exceeds 100 μm, not only the blade of the ceramic rotating body parts but also the jig for evaluating the rotating body itself may be destroyed. It was decided to. The results are shown in the following table.

[0025]

[Table 1]

Also, based on the above results, the maximum outer diameter D is 1
For 00 mm and 200 mm, the relationship of d ₁ / D is 0.2,
The relationship of d ₂ / D was set to 0.3 and 0.5, and a high-speed rotation test was performed with a maximum peripheral speed of 270 m / s by changing the number of bolts to be screwed. The maximum amount of run-out and the maximum number of revolutions immediately before stopping when an abnormality was found were measured to evaluate the effect of the bolt fastening of the jig for evaluating the rotating body.

[0027]

[Table 2]

(Embodiment 2) As shown in the sectional view of FIG.
Based on a through hole with a diameter of 20 mm drilled in the center,
Maximum outer diameter 100m with various diameters of the through hole
m, a disk made of Ni-base alloy steel having a maximum thickness of 20 mm, a shaft made of SCM435 steel having a shrink fitting allowance set at 20 μm with a difference in diameter, and a shrink fitting temperature of 30 mm.
The temperature was set to 0 ° C., and the components were integrated by shrink fitting.

Then, bolts were screwed into four screw holes evenly provided at various positions where d ₂ / D was variously set up to the disk through the step portion of the shaft and the disk was fastened to the shaft.

Using the jig for evaluating a rotating body thus obtained, a rotating body for evaluation was prepared in the same manner as in Example 1, and a high-speed rotation test was performed to evaluate the same items as in Example 1. Was. Table 3 shows the results.

[0031]

[Table 3]

(Comparative Example) As shown in the cross-sectional view of FIG. 4, a fitting portion having a step portion on a disk having the same outer diameter and the same shape as in Example 2 having a through hole having a diameter of 20 mm at the center portion. A shaft with a diameter of 14 mm was fitted, and a nut was screwed onto a thread formed at the tip of the shaft to produce a jig for evaluating a rotating body for comparison, in which the disk and the shaft were fastened.

Using the jig for evaluating the rotating body for comparison,
A rotating body for evaluation was assembled in the same manner as in Examples 1 and 2.
A high-speed rotation test was performed, and the same items as in Examples 1 and 2 were evaluated. The results are shown in Table 3.

As is evident from the above results, in the comparative example, the amount of run-out exceeded 100 μm at a maximum of 35,000 revolutions per minute, and the amount of unbalance increased 4.3 times or more before and after the test.
The coaxiality increased 1.3 times or more before and after the test, and the squareness increased 1.3 times or more before and after the test, and became worse, whereas the jigs for evaluating a rotating body according to the present invention of Examples 1 and 2 were used. It can be seen that almost no change was observed in the measured values of any of the evaluation items up to 85,000 revolutions per minute, which is the highest rotational speed in the high-speed rotation test.

The jigs for evaluating the rotating body of Sample No. 4 in Table 1 and Sample No. 7 in Table 3 showing the results of Example 1 and Example 2, respectively, were continuously operated at room temperature up to 100,000 revolutions per minute. Rotation tests were performed, and in all cases, the runout amount of the spindle was within 100 μm,
It was confirmed that the coaxiality and the squareness hardly changed.

[0036]

According to the jig for evaluating a rotating body of the present invention, after shrink-fitting a disk or hub and a shaft, the jig is further processed through the step portion of the shaft in the longitudinal direction of the shaft to reach the disk or hub. Since the bolts are screwed into the threaded holes, the connecting portion of the disk or hub for fixing the shaft at the time of the high-speed rotation test does not spread, and the fixing of the shaft is not loosened and unbalance occurs. As a result, it does not generate vibrations up to high rotation speeds, and correctly evaluates guarantee tests and destruction tests using rotating bodies such as large axial rotors and radial rotors incorporating ceramic rotating parts such as rotor blades. And the reliability can be remarkably improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a rotating body evaluation jig including a disk having a groove for incorporating a ceramic rotating body part and a shaft to be mounted on a high-speed rotation tester.

FIG. 2 Shrink-fits the concave portion of the shaft to the convex portion of the disk,
It is sectional drawing of the rotating body evaluation jig which screwed and fastened the bolt to the disk in the longitudinal direction of the shaft through the step part provided in the shaft.

FIG. 3 after shrink-fitting the shaft into the through hole of the disc,
It is sectional drawing of the rotating body evaluation jig which screwed and fastened the bolt to the disk in the longitudinal direction of the shaft through the step part provided in the shaft.

FIG. 4 shows a rotating body evaluation jig of a comparative example in which a shaft is fitted into a through hole of a disk, and a nut is screwed onto a screw formed at the tip of the fitted shaft to fasten the disk and the shaft. It is sectional drawing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotating body evaluation jig 2 Disk 3 Shaft 4 Convex part 5 Concave part 6 Through hole 7 Step part 8 Screw hole 9 Bolt

Claims (2)

(57) [Claims] 1. A convex portion provided at the center of a disk or hub of a rotating body is shrink-fitted into a concave portion provided on a shaft having a step portion, and is arranged at equal intervals through the step portion to reach the disk or hub. Bolts are screwed into a plurality of screw holes and fastened. The maximum outer diameter of the disk or hub is D, the diameter of the projection is d ₁ , and the diameter of a concentric circle with the shaft formed by the plurality of screw holes is d ₂ Wherein d ₂ / D is 0.5 or less and d ₁ / D satisfies 0.1 to 0.4. 2. A plurality of screw holes which are shrink-fitted into a through hole provided at the center of a disk or hub of a rotating body and which are arranged at equal intervals to penetrate the step and reach the disk or hub. The maximum outer diameter of the disk or hub is D, and the diameter of the through hole is d.
_3, characterized in that when the diameter of the shaft and concentric plurality of screw holes formed was d _4, where d ₄ / D is 0.5 or less and d ₃ / D satisfies the 0.1-0.4 Jig for evaluating a rotating body.