JPH078505U - Rotor balancer - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] By applying a damping force to the bearing base, the amplitude of vibration at the natural frequency of the rotor system is suppressed within the allowable range. [Configuration] A sensor 5 for detecting vibration of the bearing stand 2 is provided,
The detection signal is input to the controller 7. The controller 7 receiving this signal generates a control signal for operating the vibration actuator 6 and outputs the control signal via the power amplifier 8. When the actuator 6 operates, a sufficient damping force can be obtained, so that the amplitude of vibration at the natural frequency of the rotor system can be suppressed within a predetermined allowable range.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotor balance device used for balance adjustment of a rotating machine such as a turbine.

[0002]

[Prior art]

 The measurement (test) speed of the soft type rotor balance device is set to about 3 times the natural speed of the natural vibration of the rotor system including the rotor, bearings, and bearing bases. This is because the measured vibration value corresponds to the amount of eccentricity due to residual imbalance, and the vibration value does not change even if the measured rotation speed changes slightly.

FIG. 2 and FIG. 3 show a conventional soft type rotor balance device, in which 1 is a rotor, 2 is a bearing stand, and 3 is a stopper. In such a conventional device, since the bearing base 2 is supported by the leaf spring 4 having low rigidity, the natural frequency of the rotor system is low, and in order to increase the rotational speed of the rotor up to the measured rotational speed, It is necessary to exceed the natural frequency.

However, in the above-mentioned conventional device, since the damping is very small, the natural frequency cannot be passed, and therefore, the bearing base 2 is clamped by the stopper (for example, a hydraulic clamp mechanism) 3. By increasing the support rigidity of the rotor system by raising the natural frequency above the measured rotation speed, the rotor 1 is accelerated (at this time the natural frequency does not pass), and after reaching the measured rotation speed, the clamp Is relaxed and the natural frequency is lowered to bring it to the normal state.

That is, in order to prevent the vibration from increasing at the natural frequency of the rotor system, the stopper 3 is attached to the bearing base, the stopper 3 is loosened after the rotation has risen, and the balance is calculated using the vibration vector for the rotation frequency. Was being carried out.

[0006]

[Problems to be solved by the device]

 In the conventional soft type rotor balancing device described above, in order to prevent large vibration, the rotor is balanced using the vibration vector at a rotation speed higher than the natural frequency of the rigid body mode at several Hertz, and It was not possible to use the vibration vector at the natural frequency, which is important for balancing the accuracy.

Therefore, an object of the present invention is to suppress the amplitude of vibration at the natural frequency of the rotor system within an allowable range by applying a damping force to the bearing base.

[0008]

[Means for Solving the Problems]

 The present invention solves the above-mentioned problems, and in a soft type rotor balance device used for balance adjustment of a rotating machine, a sensor that detects the vibration of the bearing stand and the unbalanced vibration of the rotor to be balanced are An actuator for controlling the amplitude and a controller for controlling the operation of the actuator in response to the detection signal of the sensor are provided, and the amplitude of the vibration at the natural frequency of the rotor system is suppressed within a predetermined allowable range. It is a rotor balance device characterized in that it is configured.

[0009]

[Action]

 According to the above-mentioned means, the vibration of the bearing stand is detected by the sensor, and the actuator is differentially controlled by the controller based on this signal, so that the bearing stand can be made to exert a damping force. Due to this damping force, the amplitude of vibration at the natural frequency of the rotor system is suppressed within a predetermined allowable range.

[0010]

【Example】

 An embodiment of the rotor balance device according to the present invention will be described with reference to FIG. The same parts as those of the conventional example are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 1, reference numeral 2 denotes a bearing stand, and 4 denotes a leaf spring. When performing balancing, the rotor 1 (see FIG. 2) is supported by the bearing and the bearing stand 2, and for example, the rotor 1 is about 80 Rotate up to 0 rpm. In the soft type rotor balance device, since the bearing stand 2 is supported by the leaf spring 4 having low rigidity, the natural frequency of the system constituted by the rotor 1, the bearing stand 2, the leaf spring 4 and the like is low, and You will pass this in the process of rising. At that time, if there is no control, the vibration becomes large and the passage becomes impossible.

Therefore, in the present invention, the above-mentioned soft type rotor balancing device is provided with a sensor 5 for detecting the vibration of the bearing stand 2 and an exciting vibration controlling the amplitude of the unbalanced vibration of the rotor 1 to be balanced. An actuator 6 and a controller 7 for controlling the operation of the actuator 6 in response to a detection signal from the sensor 5 are provided, and the actuator 6 for vibration is operated via the power amplifier 8 so that the bearing stand 2 is dampened. It is configured to add a group.

As the sensor 5, an overcurrent type displacement meter, a conductive vibrometer, or the like can be used, and the detected vibration signal is input to the controller 7. Next, as the actuator 6 for vibration, for example, a coil is wound around the center of an E-shaped iron core, and an electromagnet is generated by passing a current through the coil to generate a magnetic field, which is proportional to the control signal from the controller 7. There is a structure in which the generated force acts on the bearing base 2. The controller 7 also A / D-converts the vibration displacement waveform detected by the sensor 5 to generate a vibration velocity signal that is advanced by 90 degrees with respect to the vibration displacement (when a conductive vibrometer is used for the sensor 5, vibration is generated). (It is not necessary to generate a speed signal because the speed is detected), and the signal level is converted, and the actuator 6 is operated as an analog signal by D / A conversion. The controller 7 generates a control signal for operating the actuator 6 from the vibration waveform detected by the sensor 5, and may be a computer or a dedicated device as long as it fulfills this function.

By the way, the vibration response of the one-degree-of-freedom system has a larger amplitude value as the damping (damping) ζ is smaller. A normal balancer has almost no damping, ζ is about 0.005, and the amplitude value is about 100 times. The damping ζ is proportional to the velocity term obtained by first-order differentiating the vibration displacement x in the following vibration equation (Formula 1).

## EQU1 ## mx + cx + kx = Fsinωt

In the present invention, the time history waveform of the vibration displacement detected by the sensor 5 is recorded by the controller 7, the differential operation is performed, and the generated velocity proportional waveform is used to generate an actuator for vibration through the power amplifier 8. 6 is activated to add damping to the bearing stand 2. That is, the vibration displacement waveform is sampled at constant time intervals Δt, and the velocity waveform is formed by sequentially performing the calculation of the following formula (Formula 2).

[Number 2] _{(V i -V i-1)} / Δt = E i

By executing such control, it takes a long time for the vibration to subside because the damping is small when the actuator 6 is not operated, but a sufficient damping force is provided by the operation of the actuator 6. It becomes possible to obtain rapid convergence of vibration. That is, by adding a sufficient damping force, the amplitude of vibration at the natural frequency of the rotor system can be suppressed within a predetermined allowable range.

[0017]

[Effect of device]

 By applying the above-described present invention, the amplitude can be suppressed within the allowable range even in natural vibration. Therefore, it is possible to use a vibration vector at a natural frequency that shows a response several times larger for the same imbalance than the conventional balancer that used a vibration vector at a rotation frequency sufficiently higher than the natural frequency. It will be possible. As a result, not only the time required for the balance work can be significantly shortened, but also the final balance accuracy can be improved.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a rotor balancing device according to the present invention.

FIG. 2 is a side view showing an outline of a rotor balance device.

FIG. 3 is a front view (viewed from an arrow A in FIG. 2) showing a conventional rotor balance device.

[Explanation of symbols]

 1 rotor 2 bearing base 3 stopper 4 leaf spring 5 sensor 6 actuator 7 controller 8 power amplifier

Claims (1)

[Scope of utility model registration request] 1. A soft type rotor balance device used for balance adjustment of a rotating machine, a sensor for detecting vibration of a bearing stand, an actuator for controlling amplitude of unbalanced vibration of a rotor to be balanced, said A rotor balance comprising: a controller for controlling the operation of the actuator in response to a detection signal from a sensor, and configured to suppress the amplitude of vibration at the natural frequency of the rotor system within a predetermined allowable range. apparatus.