JP3903383B2 - Eccentricity detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an eccentricity detection device for detecting the amount of deflection of a rotor of a rotating machine, and is particularly used for a turbine generator.
[0002]
[Prior art]
Rotating machines such as rotors of turbine generators that rotate at high speeds, such as rotors of turbine generators, start to rotate at a high speed of several thousand rpm for power generation as they are deflected (eccentric) after a long time with rotation stopped. Then, the rotor vibrates vigorously due to eccentricity, and the turbine generator may be destroyed. Therefore, the eccentric amount of the rotor of the turbine generator is reduced by continuing ultra-low speed rotation of 2 to 3 rpm for a predetermined time before starting rotation. At this time, the eccentric amount of the rotor is measured by the eccentricity detecting device.
[0003]
For example, as disclosed in FIG. 1 of Patent Document 1, a conventional eccentricity detection apparatus rotates a rotor by attaching a precisely processed cylinder or disk (hereinafter referred to as an eccentricity detection disk) to the rotor. Alternatively, fluctuations in the position of the outer periphery of the disk are accurately measured by, for example, an eddy current sensor, and the eccentricity of the rotor is detected as an electrical signal.
[0004]
An eddy current sensor is used to detect eccentricity when eddy current is generated on a cylinder or disk that is located closer to the magnetic field transmitted by flowing current in the eddy current sensor, and the current flowing through the eddy current sensor changes. The distance between the disk and the tip of the eddy current sensor can be measured.
Recent eccentricity detection devices measure the gap with the eddy current sensor by attaching a dedicated eccentricity detection disk to the turbine generator rotor. The eddy current sensor is supported by a dedicated jig and connected to a monitoring device outside the turbine generator with a cable. The amount of eccentricity of the turbine generator rotor is confirmed by a monitoring device, and after confirming that the amount of eccentricity has decreased, high-speed rotation for power generation is started.
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 5-10705 FIG.
[0006]
[Problems to be solved by the invention]
Since the conventional eccentricity detecting device is configured as described above, it is necessary to attach a precise eccentricity detecting disk exclusively to the rotor, and the processing accuracy, composition, roughness, and material of the surface of the eccentricity detecting disk are required. There is a problem that there may be a difference between the detected value of the eddy current sensor and the actual eccentricity due to the difference.
[0007]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an eccentricity detection device capable of detecting the amount of eccentricity without using a dedicated disk for detecting eccentricity.
[0008]
[Means for Solving the Problems]
A contact-type eccentricity detection device according to the present invention includes an outer tube disposed in a direction orthogonal to the axis of the rotor of the rotating machine,
An inner pipe disposed inside the outer pipe and movable in the axial direction of the outer pipe;
A shoe that is attached to one end of the inner tube and that contacts the outer peripheral surface of the rotor to transmit the eccentric amount of the rotor to the inner tube;
A sensor is provided in the vicinity of the other end of the inner pipe and detects the eccentric amount of the rotor transmitted by the inner pipe.
Since the sensor captures the movement of the shoe that directly detects the eccentricity of the rotor, no eccentricity detecting disk is required.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Hereinafter, the eccentricity detection apparatus of Embodiment 1 of this invention is demonstrated based on figures. A case of a turbine generator having an outer shell (casing) 21 will be described. A base 20 is fixed to the casing 21. An outer tube 17 extending in a direction perpendicular to the central axis of the rotor 11 is fixed to the base 20. An inner tube 16 that freely moves in the tube axis direction is inserted into the outer tube 17. A connecting pipe 13 is fixed to the inner pipe 16 via an insulating pipe 14. A shoe 12 made of a low friction material such as white metal is fixed to the tip of the connecting pipe 13, and the shoe 12 is in contact with the outer peripheral surface of the rotor 11.
[0010]
The inner tube 16 or the insulating tube 14 is gently held by the outer tube 17 by a leaf spring 15 so as not to rattle inside the outer tube 17 and not to lose the degree of freedom in the tube axis direction. Since the inner tube 16 is pressed with a predetermined strength in the direction of the rotor 11 by a pressing spring 18 provided inside the outer tube 17, the shoe 12 is pressed against the rotor 11.
A target 19 made of, for example, a magnetic material such as SB450 is provided at the upper end of the inner tube 16 in the figure, and is configured so that the distance from the eddy current sensor 22 fixed to the fixing jig 23 can be measured. Yes. The eddy current sensor 22 is connected to an external monitor device 25 by a cable 24. The sensor 22, the jig 23, and the cable 24 are accommodated in a housing 26, and the housing 26 is attached to the base 20. In FIG. 1, the housing 26 is shown floating from the base 20 for convenience of explanation.
[0011]
Next, the operation will be described. The base 20 is attached to the turbine generator body so that the shoe 12 contacts the turbine generator rotor 11. The shoe 12 is connected to an insulating pipe 14 by a connecting pipe 13, and the insulating pipe 14 is connected to an inner pipe 16. The inner pipe 16 is pressed against the turbine generator rotor 11 by a leaf spring 15 connected to the outer pipe 17 and a pressing spring 18 in the outer pipe 17. Since the inner tube 16 freely moves in the tube axis direction in the outer tube 17, the amount of eccentricity when the turbine generator rotor 11 rotates once is directly transmitted to the target 19. Since the housing 26 is fixed to the base 20, the eddy current sensor 22 fixed in the housing 26 can measure the fluctuation of the position of the target 19, and therefore the eccentric amount of the turbine generator rotor can be measured. it can.
Due to the potential difference between the rotor 11 and the casing 21 caused by the insulating tube 14, no current flows through the inner tube 16 and does not affect the measurement.
[0012]
In the first embodiment, the amount of eccentricity of the turbine generator rotor 11 is directly transmitted to the target 19, so that a dedicated eccentricity detection disk is not required, and an existing monitor device is used to obtain a highly reliable device. be able to. The magnetic sensor includes the eddy current sensor shown in the conventional explanation and can be generally applied at low cost.
[0013]
In the above description, the rotor of the turbine generator has been described as an example. However, the present invention is not limited to this, and can be applied to all large rotating machines. Further, the configuration shown in FIG. 1 can be partially modified as shown below. That is, although the sensor is described as an eddy current type, any type of magnetic sensor may be used as long as it can detect a change in the position of the target 19 made of a magnetic material. Although the inner pipe 16 is called a pipe, it does not have to be a so-called pipe, and may be a rod-like one. Further, instead of providing the target 19, the end of the inner tube 16 may be used as it is. The weight of the inner tube 16 or the like may be used instead of the pressing spring 18. In FIG. 1, the shoe 12 is pressed against the upper surface of the rotor 11. However, the shoe 12 may be pressed upward from below the rotor 11. If the inner tube 16 is made of, for example, an insulating material, the insulating tube 14 need not be provided. Although not shown in the drawing, when the inside of the casing 21 needs to be kept airtight, an airtight process is performed at a portion where the cable 24 passes through the housing 26.
[0014]
Embodiment 2. FIG.
In the first embodiment, since the target 19 is made of a magnetic material, it is necessary to manage the magnetic characteristics to some extent. Therefore, as shown in FIG. 2, an optical position detection sensor 27 and a monitor device 28 corresponding thereto may be provided to measure the variation amount of the target 19 regardless of the magnetic characteristics of the target 19. In this case, the target 19 is a mirror or shutter-like object (referred to as an optical material) that reflects or shields light, and the optical position detection sensor 27 detects a change in light amount or a change in wavelength accompanying the movement of the target 19. To detect. Thereby, the management cost of the target can be reduced as compared with the case where a magnetic material is used for the target 19. Since the optical position detection sensor 27 is not easily affected by electromagnetic waves, even if a slight current flows through the turbine generator due to the low speed operation of the turbine generator, the optical position detection sensor 27 is not easily affected.
[0015]
Embodiment 3 FIG.
When the amount of eccentricity is small, a sensor is indispensable for measuring the eccentricity.However, when the amount of eccentricity is large, for example, immediately after installation of the turbine generator, it is more efficient to visually check the eccentricity without using the sensor. It can be expensive. Therefore, as shown in FIG. 3, the eccentric amount is directly measured at the site by attaching a gauge 29 that directly contacts the target 19, a spring 30 that presses the gauge 29 against the target 19, and a pointer 31 that reads the scale of the gauge. be able to. Here, as the gauge 29 and the pointer 31, for example, a commercially available micro gauge or the like may be used, and the weight of the gauge 29 may be used instead of the spring 30. When it is not desired to provide a hole for penetrating the gauge 29 in the housing 26, the gauge 29 is structured not to protrude from the housing, and an airtight glass window is provided on the upper surface or side surface of the housing 26 so that the scale of the internal gauge 29 is provided. Read from outside.
[0016]
Embodiment 4 FIG.
In the configuration of the first to third embodiments, the shoe 12 is always pressed against the rotor 11. Therefore, if the rotor 12 is rotated at a high speed as it is, the wear of the shoe 12 may be accelerated. The eccentricity does not always have to be measured while the turbine is rotating at high speed. Therefore, as shown in FIG. 4, a metal rod 33 that mechanically pulls the inner tube 16 and the shoe 12 away from the turbine generator rotor 11 by a fixing plate 32 from below the insulating tube 14 is provided. Further, by attaching a screw / nut 34 for moving the metal rod 33 up and down and fixing it, the rotor 11 and the shoe 12 can be separated during high-speed rotation of the turbine generator that does not use the eccentricity detection device. As a result, wear of the shoe 12 can be reduced, and trouble during high-speed rotation can be prevented. The portion where the metal rod 33 penetrates the housing 26 is hermetically sealed as necessary. The fixing plate 32, the metal bar 33, and the screw / nut 34 are the lifting device referred to in the present invention.
In this case, the lifting device simply needs to pull the shoe 12 away from the outer peripheral surface of the rotor. Therefore, the lifting device does not necessarily have the structure shown in FIG. 4, for example, a plate structure that pushes the target 19 upward from below. Good.
[0017]
【The invention's effect】
As described above, according to the eccentricity detecting device of the present invention, the eccentricity of the rotor is directly taken out by the shoe that directly contacts the outer peripheral surface of the rotor, so that it is necessary to install a dedicated eccentricity measuring disk. The effect that there is no is obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional side view showing an eccentricity detection apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a cross-sectional side view showing an eccentricity detection device according to a second embodiment of the present invention.
FIG. 3 is a sectional side view showing an eccentricity detection device according to a third embodiment of the present invention.
FIG. 4 is a sectional side view showing an eccentricity detection device according to a fourth embodiment of the present invention.
[Explanation of symbols]
11 rotor, 12 shoe, 13 connecting pipe,
14 Insulating tube, 15 Leaf spring, 16 Inner tube, 17 Outer tube,
18 pressing spring, 19 target, 20 base,
21 casing, 22 sensor, 23 mounting jig,
25 Monitor, 26 Housing, 27 Light sensor,
29 gauge, 30 leaf spring, 31 pointer, 32 fixing plate,
33 metal bars, 34 screws / nuts.

Claims (7)

An outer tube arranged in a direction perpendicular to the axis of the rotor of the rotating machine,
An inner pipe disposed inside the outer pipe and movable in the axial direction of the outer pipe;
A shoe that is attached to one end of the inner tube and that contacts the outer peripheral surface of the rotor to transmit the eccentric amount of the rotor to the inner tube;
An eccentricity detection device comprising a sensor provided in the vicinity of the other end of the inner tube and detecting an eccentricity amount of the rotor transmitted by the inner tube. 2. The eccentricity detecting device according to claim 1, further comprising a magnetic material attached near the other end of the inner tube, wherein the sensor is a magnetic sensor that magnetically detects a change in position of the magnetic material. The eccentricity detection according to claim 1, wherein an optical material that is attached near the other end of the inner tube and reflects or shields light, and the sensor is an optical sensor that optically detects a change in position of the optical material. apparatus. 4. The eccentricity detection device according to claim 2, further comprising a measurement gauge that directly reads a position of the inner tube in a direction orthogonal to the axis of the rotor. The eccentric detection device according to claim 1, further comprising a pressing spring that presses the shoe against the rotor via the inner tube. The eccentricity detecting device according to claim 1, further comprising a lifting device that holds the shoe in a position not in contact with the rotor. The eccentricity detecting device according to claim 5, further comprising an electrical insulating material between the shoe and the pressing spring.

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