JPH0815075A - Low-and high-speed balancing machine for rotating body - Google Patents

Abstract

PURPOSE:To perform both low- and high-speed balancing tests with one balancing machine by using a bearing supporting member having low horizontal supporting rigidity and a bearing stand having high vertical supporting rigidity and a magnetic damper as a vibration damping capacity for the low-speed balancing tests and as a spring term for the high-speed balancing tests. CONSTITUTION:At the time of performing low-speed balancing tests, the rotating speed of a rotating body 2 cannot be increased to a rotating speed for test, because the unbalanced vibration of the body 2 becomes excessively large due to the low supporting rigidity of a bearing. Therefore, a magnetic damper 8 is used as a vibration damping capacity. Namely, the vibration of the body 2 is suppressed by fetching the horizontal shaft vibrational waveform of the rotating body 2 detected by means of a horizontal shaft vibration meter 7 to a computer 10 and differentiating the waveform, and then, actuating the damper 8 by introducing the differentiated signal to the damper 8 through a power amplifier 9. At the time of performing high-speed balancing tests, the damper 8 is used as a spring term. Therefore, the same effect as that obtained when the supporting rigidity of the bearing is improved can be obtained by actuating the damper 8 by performing antiphase processing on the detected shaft vibrational waveform.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low / high speed equilibrium test apparatus applied to low speed and high speed equilibrium tests of rotating bodies having elastic properties such as turbines and gas turbines.

[0002]

2. Description of the Prior Art Conventionally, elastic rotors such as turbines and gas turbine rotors are low-speed balanced by a rigid bearing type or soft bearing type low speed equilibrium test device, and then the rotational speed is increased to a practical rotational speed. High-speed balance testing equipment is used for high-speed balancing.

In the case of the rigid bearing type, the low speed equilibrium test device is a system for accurately measuring a minute centrifugal force due to the imbalance of the rotating body at a low speed revolution. Therefore, when the revolution speed is increased to a practical revolution speed. 100 times or more (300 rpm to 30
The centrifugal force (when the rotation speed is increased to 00 rpm) acts, and it is very difficult to establish both. In addition, since the soft bearing type has a low support rigidity, it causes excessive vibration and cannot increase the rotation speed to a practical rotation speed.

That is, the test equipment used for the low speed equilibrium test apparatus cannot be applied to the high speed equilibrium test in which the rotational speed is increased up to the practical rotational speed.

Further, in the high-speed balance test, since the rotating body is rotated at a high speed, wind damage due to the blades is large in the atmosphere and a large driving power is required. Therefore, in order to reduce the driving power, a vacuum chamber that can evacuate the inside is usually used. This means that the procedure is to carry out the low speed equilibrium test, then move the place to the vacuum chamber, re-install and assemble, and perform the high speed equilibrium test.

Japanese Laid-Open Patent Publication No. 5-52695 has been proposed as a bearing base structure for both low speed and high speed balance tests.
The outline of the proposal is to use a leaf spring for the bearing support,
A second reinforcing spring, a spring for coupling and separating, and a pressure device are provided to change the bearing support rigidity.

[0007]

The above-mentioned conventional low speed and high speed equilibrium testing devices have the following problems to be solved.

That is, the bearing device used in the conventional low speed equilibrium test device and high speed equilibrium test device cannot be used for both of them, so that it is necessary to change the bearing device each time. Therefore, carrying in the rotating body, setup of the test equipment,
The centering, the bearing flushing work, etc. are all duplicated work, and there is a problem that a great amount of time is wasted.

Further, in JP-A-5-52695, a large number of springs and pressurizing devices are required for varying the bearing support rigidity, which complicates the structure, and the support rigidity is a constant value determined by the rigidity of the augmenting spring. Therefore, there was a problem that the rigidity could not be finely adjusted.

In order to solve the above problems, it is an object of the present invention to provide a low / high speed equilibrium test device for a rotating body, which is capable of performing both low speed equilibrium and high speed equilibrium tests with a single device.

[0011]

Means for Solving the Problems As a means for solving the above problems, the present invention provides a bearing support member having a low horizontal support rigidity capable of low-speed balancing and a bearing support member in a rotor balance test apparatus. A bearing stand having a high vertical support rigidity capable of high-speed balancing through which the bearing of the rotating body is supported, and a magnetic damper capable of changing the horizontal support rigidity of the bearing support member with respect to the bearing stand; A vibrometer capable of measuring axial vibration of the body in two directions, a vertical direction and a horizontal direction, and a computer for controlling the magnetic damper so as to obtain a required supporting rigidity by performing a balance calculation based on vibration data measured by the vibrometer. An object of the present invention is to provide a low / high speed equilibrium testing device for a rotating body, which comprises:

[0012]

Since the present invention is constructed as described above, it has the following actions.

That is, first, since the bearing of the rotating body is supported by the bearing base through the bearing support member having a low horizontal support rigidity, it is softly supported by the low-rigidity bearing support member in the low speed balance test. Perform the test as it is, calculate the unbalance amount using the horizontal axis vibration data,
Perform balancing work. At this time, since the supporting rigidity is weak in the horizontal direction, excessive vibration occurs when passing through the natural frequency of the rotating body. This vibration waveform is detected by the axis vibrometer,
The computer differentiates and activates the magnetic damper as a speed signal. Since the speed signal acts as a vibration damping function, the vibration can be reduced and the natural frequency of the rotating body can be passed with low vibration. If a velocity type detector is used as the vibrometer of the shaft, the differentiating function is unnecessary.

When a high speed balance test is performed next, the bearing support rigidity is increased by causing the magnetic damper to act as a spring. That is, by generating a control signal with a phase opposite to the vibration waveform detected by the vibrometer by the computer and operating the magnetic damper, it becomes a rigidity term that is coupled in parallel with the original flexible support spring, and the support rigidity is Can be increased. At that time, since the bearing stand has a high vertical support rigidity, the data is not disturbed. In this way, by making the magnetic damper act as a damping force and a spring term,
It is possible to use the test device of the same bearing stand as a combination type of the low speed equilibrium test device and the high speed equilibrium test device.

Furthermore, the bearing support rigidity when installed in an actual plant is not a constant value, but has complicated characteristics as shown in FIG. 4, for example. However, since the support rigidity can be easily controlled by using the magnetic damper having the above-described configuration, the characteristics equivalent to the support rigidity of the actual plant can be easily achieved by changing the amplification level of the signal level to be controlled for each frequency. You can also

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram of this embodiment, FIG. 2 is a cross-sectional view of a bearing portion thereof, FIG. 3 is an explanatory diagram of control signals of a magnetic damper used in this embodiment, and FIG. It is a figure of support rigidity.

In FIGS. 1 and 2, reference numeral 1 denotes an equilibrium test apparatus according to the present embodiment. As shown in both figures, the rotating body 2 has a bearing base 4 on both sides of which a bearing support member 5 having low supporting rigidity is interposed.
Is supported by a bearing 3 supported by the
The drive motor 6 is used. The vertical support rigidity of the bearing stand 4 is set to be high. This structure is similar to the conventional type. In this embodiment, the bearing support member 5 shown in FIG. 2 is set to have low horizontal support rigidity by a leaf spring or the like as in the soft bearing type low speed equilibrium test device, and the bearing 3 is used.
A magnetic damper 8 is installed in the lower part, a power amplifier 9 and a calculator 10 are provided, and the magnetic damper 8 can be controlled and the support rigidity of the bearing support member 5 can be changed.

Next, the operation of the above configuration will be described.

First, when a low speed equilibrium test is carried out, the bearing support rigidity is low, so in this state, the unbalanced vibration of the rotor 2 becomes excessive, and the number of revolutions becomes the test number of revolutions (200).
It is not possible to accelerate to ~ 300 rpm). Therefore,
The magnetic damper 8 acts as a vibration damping function. Specifically, as shown in FIG. 1 and FIG. 3, a shaft vibration waveform detected by the horizontal shaft vibrometer 7 is taken into a computer 10, differentiated, and the signal is passed through a power amplifier 9 to a magnetic damper. Vibration is suppressed by leading to 8 and operating.

Next, when a high speed balance test is performed, the magnetic damper 8 is operated as a spring term. The detected shaft vibration waveform is subjected to anti-phase processing by the computer 10 and the magnetic damper 8 is operated, so that the same effect as that when the bearing support rigidity is increased can be obtained.

Further, the bearing support rigidity of an actual plant is not a constant value, but has complicated characteristics as shown in FIG. 4, and it is difficult to reproduce it with a fixed shape (leaf spring or the like). . However, in the rigidity variable system using the magnetic damper 8 of the present embodiment, it suffices to change the control signal level of the computer 10 to a large or small level, which is easily applicable.

As described above, according to this embodiment, the bearing 3 of the rotating body 2 is suspended on the bearing stand 4 having a high vertical support rigidity via the bearing support member 5 having a low horizontal support rigidity. A magnetic damper 8 is installed to suspend and control the support rigidity of the bearing support member 5, and the shaft vibration data of the rotor 2 detected by the shaft vibrometer 7 is used to rotate a wide range from a low speed region to a high speed region through a computer 10. Since the support rigidity of the magnetic damper 8 can be controlled so as to be suitable for the equilibrium test in 1), there is an advantage that both the low speed equilibrium test and the high speed equilibrium test can be performed by a single test apparatus.

Further, since the support rigidity can be changed steplessly (continuously) through the magnetic damper 8, there is an advantage that one apparatus can cope with any rotation speed test.

Further, the configuration of the apparatus is the same as that of the conventional example, the shaft vibrometer 7, the magnetic damper 8, the power amplifier 9, and the computer 1.
Since the object is achieved only by adding 0, there is an advantage that it is extremely simple and can be obtained at low cost.

Further, there is an advantage that not only the low / high speed equilibrium test but also complicated bearing supporting characteristics of an actual machine such as an actual plant can be easily reproduced.

Further, since the test under various conditions as described above can be carried out by one apparatus, there is an advantage that the test can be carried out extremely efficiently (in a short period).

[0027]

Since the present invention is constructed as described above, it has the following effects (1) to (5).

(1). It is possible to perform the low speed equilibrium test device and the high speed equilibrium test device on the same bearing stand.

(2). By using the low-speed and high-speed type, it is sufficient to carry out the loading and installation of the rotating body, the installation and assembly of the bearing stand, the flushing of the bearing oil, and the like, which have been conventionally performed twice.

(3). It is possible to significantly reduce the construction period and cost of the balance test work.

(4). It is possible to easily reproduce the complicated bearing support characteristics of an actual plant.

(5). It is possible to perform balancing work according to the actual plant.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a low / high speed equilibrium testing device for a rotating body according to an embodiment of the present invention,

FIG. 2 is a transverse cross-sectional view of a bearing base of the equilibrium test apparatus according to the above embodiment,

FIG. 3 is an explanatory diagram of a control signal of a magnetic tamper used in the above embodiment,

FIG. 4 is a bearing support rigidity diagram in an actual plant shown for reference.

[Explanation of symbols]

 1 Balance Test Device 2 Rotating Body 3 Bearing 4 Bearing Stand 5 Bearing Support Member 6 Drive Motor 7 Axis Vibration Meter 8 Magnetic Damper 9 Power Amplifier 10 Computer

Claims (1)

[Claims] 1. A rotating body equilibrium test apparatus capable of low-speed balancing, having a low horizontal support rigidity, and a high-speed balancing supporting a bearing of a rotating body via the bearing supporting member. A bearing stand having a high vertical support rigidity, a magnetic damper capable of changing the horizontal support rigidity of the bearing support member with respect to the bearing stand, and a shaft vibration of the rotating body in two directions, a vertical direction and a horizontal direction. A vibrometer that can be measured over a range, and a computer that controls the magnetic damper so as to achieve a required supporting rigidity by performing a balance calculation based on the vibration data measured by the vibrometer. Low / high speed balance testing device.