JPH08101089A - Jig for rotating body evaluation - Google Patents

Abstract

(57) [Summary] [Purpose] During high-speed rotation testing, the joint between the shaft and disk or hub does not expand, the shaft is not loosely fixed, and no imbalance occurs. It is possible to correctly evaluate a guarantee test and a destructive test using a large-sized rotating body incorporating a manufactured rotating body component, and it is possible to significantly improve reliability. [Structure] A convex portion 4 provided at the center of a disc 2 is shrink-fitted with a concave portion 5 formed at one end of a shaft 3, or
After the shaft 3 is shrink-fitted in the through hole 6 provided in the center of the disc 2, a plurality of holes are formed at equal intervals in the longitudinal direction of the shaft 3 through the step portion 7 provided in the shaft 3. A bolt 9 is screwed into the screw hole 8 and fastened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention applies a high-speed rotation of a ceramic rotor component such as a rotor blade made of ceramics incorporated in a large axial rotor or radial rotor, which is applied to a gas turbine or a steam turbine. The present invention relates to a rotating body evaluation jig used for a warranty test or a destructive test that is performed by performing the evaluation.

[0002]

2. Description of the Related Art In recent years, ultra-precision rotary bodies in various industrial machinery and rotary body components used in high temperature atmosphere have small thermal expansion, large mechanical strength, excellent heat resistance and wear resistance, In addition, oxide ceramic sintered bodies such as alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ) and silicon nitride (Si ₃ N ₄ ), which have the characteristic that they can realize weight reduction due to their small specific gravity, Sialon and silicon carbide (Si
The use of non-oxide ceramic sintered bodies such as C) has been variously studied and proposed.

Generally, 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 in a gas turbine, a steam turbine or the like is a metal rotor during operation. Similarly, it rotates at a high speed of tens of thousands to 100,000 rpm.

Therefore, in order to evaluate and guarantee whether or not the ceramic rotating body parts have a performance of a certain level or more, along with various non-destructive inspections such as X-ray radiography, the ceramic rotating body The reliability test is performed by assembling the parts into an evaluation jig and performing a guarantee test to actually rotate at high speed on all products, or to perform a destructive test at high speed rotation until breaking to clarify the limit performance. I try to secure it.

In such guarantee test and destructive test, a metal shaft is shrink-fitted or press-fitted onto a metal disk or hub.
After using a jig for evaluation having a structure that is fixed by screws or fixed with an adhesive or the like, and after incorporating a ceramic rotating body part to be evaluated in a locking portion provided on the circumferential surface of the jig for evaluation,
The balance of the evaluation rotating body was corrected, and the rotating body for evaluation was mounted on a high-speed rotation tester to conduct the test (see Japanese Patent Publication No. 2-20801).

[0006]

However, although the fixing structure is considered to be applicable to a radial type rotor such as a small axial type rotor or a turbocharger, a gas turbine having a maximum outer diameter of more than 100 mm or 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 body component, a metal disk 13 fixed by a nut 12 to a shaft 11 for attachment to a high speed rotation tester (not shown) Due to the influence of centrifugal force, the joint 11 with the shaft 11 spreads to loosen the fixation of the shaft 11, imbalance occurs, and vibration easily occurs at high speed rotation, so that the guarantee test and the destructive test can be correctly evaluated. 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 to solve the above problems, and an object of the present invention is to mount it 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 connecting part of the disk or hub for fixing the shaft does not expand, and the fixing of the shaft does not loosen to cause imbalance, and as a result,
As described above, a jig for rotating body evaluation that does not generate vibrations even at high rotational speeds and has excellent reliability that can correctly evaluate the warranty test and destructive test of large rotating bodies such as axial type rotors and radial type rotors. It is intended to be provided.

[0008]

In the jig for evaluating a rotating body of the present invention, the maximum outer diameter of a metal disk or hub constituting the rotating body is D, and the diameter of a convex portion provided at the center thereof is d ₁ 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. A plurality of screw holes having a center concentric with the shaft and having a diameter of d ₂ in the longitudinal direction of the shaft through the stepped portion until reaching the disc or the hub. It is characterized in that bolts are respectively screwed into screw holes satisfying a relationship of ₂ / D of 0.5 or less to fasten the shaft and the disc or the hub.

Alternatively, when the maximum outer diameter of the metal disk or hub constituting the rotating body is D and the diameter of the through hole provided at the center thereof is d ₃ , d ₃ / D is 0.1 to 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 the stepped portion provided on the shaft is further penetrated to the disc or the hub in the longitudinal direction of the shaft. Up to this point, a plurality of screw holes that are concentric with the shaft and that have a diameter of d ₄ and whose centers are on the circumference are provided at equal intervals, and bolts are screwed into the screw holes with a d ₄ / D relationship of 0.5 or less. The shaft and the disc or the hub are fastened together.

If the relationship d ₁ / D between the maximum outer diameter of the metal disk or hub constituting the rotating body of the present invention and the diameter of the convex portion provided at the center thereof is less than 0.1, it is burned during the high speed rotation test. It is not preferable because excessive torsional stress is generated in the fitted convex portion and the balance tends to be lost, and the incorporated ceramic rotating body component may be destroyed.

On the other hand, when d ₁ / D exceeds 0.4,
Since extremely large stress is applied to the screwed bolts, the strength of the bolts is exceeded, and there is a great risk of breaking below the neck of the bolts, so the above d ₁ / D is limited to the range of 0.1 to 0.4. The range of 0.1 to 0.3 is particularly 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 It is not desirable because it breaks from under the neck or the shaft corresponding to the end of the convex portion that is shrink-fitted is deformed and the balance is lost.

Further, when the relationship of d ₃ / D in the present invention is less than 0.1, excessive torsional stress is generated in the shrink-fitted shaft during high-speed rotation test, resulting in unbalanced rotation of the built-in ceramic rotation. If the relationship d ₃ / D exceeds 0.4, the tensile stress generated by the centrifugal force may become excessive and the disc or hub itself may be damaged. .

Therefore, the relationship of d ₃ / D is 0.1 to
The range is limited to 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, the concave portion of the shaft for mounting the rotating body on the high-speed rotation tester is the convex portion of the disc or the hub, or the shaft penetrates the disc or the hub of the rotating body. The disk or hub is screwed into each of the holes, and the disc or hub is screwed and fastened through a stepped portion provided on the shaft in the longitudinal direction of the shaft, thereby pulling the coupling portion of the disc or hub and the shaft in the outer peripheral direction. The stress that tends to spread out is suppressed by the anchor effect of the bolt, and the influence of centrifugal force generated at high speed rotation is prevented.

[0016]

EXAMPLES The following is a description of the rotating body evaluation jig of the present invention.
Detailed description will be made with reference to 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 component and a shaft for mounting on a high-speed rotation tester (not shown).

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

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

In the jig for evaluating a rotating body of the present invention, it is desirable that the screw holes 8 are provided at at least 4 to 8 places at equal intervals, and from the viewpoint of the amount of shake of 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.
Based on a diameter of 12 mm and a length of 15 mm at the center, an outer diameter of 100 mm having a convex portion with variously set dimensions of the diameter,
For discs made of Ni-based alloy steel with a maximum thickness of 20 mm,
Steel type having a recess formed by setting the shrink fitting allowance at the difference between the inner and outer diameters to 20 μm is made of SCM435 and has a diameter of 20 mm
The shaft was heat-fitted and integrated by shrink-fitting at a temperature of 300 ° C.

Next, bolts were screwed into four screw holes evenly provided at four positions where d ₂ / D was set variously through the stepped portion of the shaft until the disc was fastened to the shaft and the disc.

In the thus obtained jig for evaluating a rotating body, a blade of a ceramic rotating body part made of a silicon nitride sintered body was installed in the groove of the disk and the balance was corrected.
It was set in a cold spin tester and a high-speed rotation test was performed at room temperature with a maximum rotation speed of 85,000 rotations per minute.

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

[0025]

[Table 1]

Based on the above result, the maximum outer diameter D is 1
The relationship of d ₁ / D is set to 0.2 for 00 mm and 200 mm,
By setting the relationship of d ₂ / D to 0.3 and 0.5, and performing a high-speed rotation test in which the peripheral speed with the number of bolts screwed in changed to 270 m / s as the maximum speed, a spindle rotating at high speed was tested. The maximum amount of runout and the maximum number of revolutions immediately before stopping when an abnormality was observed were measured to evaluate the effect of 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 disc made of Ni-based alloy steel with a maximum thickness of 20 mm, a shaft made of SCM435 steel type with a shrink fitting margin set to 20 μm due to a diameter difference, and a shrink fitting temperature of 30
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 to reach the disc through the stepped portion of the shaft, and the shaft and the disc were fastened.

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

[0031]

[Table 3]

(Comparative Example) As shown in the sectional view of FIG. 4, a disc having the same outer diameter and the same shape as in Example 2 having a through hole with a diameter of 20 mm at the center, has a stepped portion on a disc. A shaft having a diameter of 14 mm was fitted, and a nut was screwed to a screw portion formed at the tip of the shaft to fasten the disc and the shaft to produce a comparative rotating body evaluation jig.

Using the rotating body evaluation jig for comparison,
Assembling a rotating body for evaluation 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 also shown in Table 3.

As is clear from the above results, in the comparative example, the shake amount exceeds 100 μm at the maximum of 35,000 rpm, and the unbalance amount increases by 4.3 times or more before and after the test.
The coaxiality increased by 1.3 times or more before and after the test, and the squareness increased by 1.3 times or more before and after the test and deteriorated. On the other hand, the rotating body evaluation jigs of Examples 1 and 2 according to the present invention. It can be seen that, in any of the evaluation items, almost no change is observed in the measured value up to the maximum number of rotations in the high-speed rotation test of 85,000 rpm.

The rotor evaluation jigs of Sample No. 4 in Table 1 and Sample No. 7 in Table 3 showing the results of Example 1 and Example 2 are continuously operated at high speed at room temperature up to 100,000 revolutions per minute. A rotation test was conducted, and in all cases, the amount of runout of the spindle was within 100 μm, and the unbalance amount,
It was confirmed that the coaxiality and the squareness hardly changed.

[0036]

EFFECT OF THE INVENTION In the jig for evaluating a rotating body of the present invention, after a disc or a hub and a shaft are shrink-fitted and coupled together, the disc or the hub is further processed by penetrating the stepped portion of the shaft in the longitudinal direction of the shaft. Since the bolt is screwed into the screw hole provided, the connecting portion of the disk or hub for fixing the shaft during the high-speed rotation test does not spread, and the fixing of the shaft does not loosen to cause imbalance. As a result, vibrations do not occur up to high rotation speeds, and correct evaluations of guarantee tests and destructive tests are performed using rotors such as large-sized axial rotors and radial rotors that incorporate ceramic rotor components such as rotor blades. Therefore, the reliability can be significantly improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a jig for evaluating a rotating body including a disk having a groove for incorporating a ceramic rotating body component and a shaft for attaching to a high-speed rotation tester.

[FIG. 2] The recess of the shaft is shrink-fitted to the protrusion of the disk,
FIG. 6 is a cross-sectional view of a jig for evaluating a rotating body in which bolts are screwed and fastened to a disk in a longitudinal direction of the shaft through a step provided on the shaft.

FIG. 3 After shrink-fitting the shaft in the through hole of the disc,
FIG. 6 is a cross-sectional view of a jig for evaluating a rotating body in which bolts are screwed and fastened to a disk in a longitudinal direction of the shaft through a step provided on the shaft.

FIG. 4 shows a rotating body evaluation jig of a comparative example in which a shaft is fitted in a through hole of a disc, and a nut is screwed to a screw portion formed at the tip of the fitted shaft to fasten the disc and the shaft. FIG.

[Explanation of symbols]

 1 Jig for Rotating Body 2 Disk 3 Shaft 4 Convex part 5 Recessed part 6 Through hole 7 Step part 8 Screw hole 9 Bolt

Claims (2)

[Claims] 1. A convex portion provided at the center of a disc or a hub of a rotating body is shrink-fitted into a concave portion provided on a shaft having a step portion, and the protrusions are arranged at equal intervals through the step portion to reach the disc or hub. A bolt is screwed into and fastened to a plurality of screw holes, the maximum outer diameter of the disk or hub is D, the diameter of the convex portion is d ₁ , and the diameter of a shaft and a concentric circle formed by the plurality of screw holes is d _2. and the time, d ₂ / D is rotator evaluation jig, characterized in that and 0.5 or less d ₁ / D satisfies the 0.1 to 0.4. 2. A plurality of screw holes formed by shrink-fitting a shaft having a step portion into a through hole provided at the center of a disk or hub of a rotating body and penetrating the step portion to reach the disk or hub. Bolts are fastened by bolts to the disk, and 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 rotating body evaluation.