JPH08136337A - Vibration indicator probe device - Google Patents

Abstract

PURPOSE: To make possible the execution of stable measurement for a long period without stopping a turbine, by conducting pressure regulation from outside a probe by introducing gas into a pressure ring provided between a coil spring and the upper end part inside a protective tube. CONSTITUTION: While the positional relationship between a shaft 2 and a protective tube 1 is maintained by always pressing the shaft 2 onto a main shaft of a turbine generator by a coil spring 7 adjusting the movement in the axial direction of the shaft 2 having a contactor 3 fitted to one end a vibration probe is fitted to a casing of a turbine main body. Thereby the vibration of the turbine shaft can be transmitted exactly to a vibration indicator 21 through the shaft 2. When the contactor 3 is worn out, the spring 7 stretching is pressed by introducing air into a pressure ring 31 shaped like a doughnut (double cylinder) and inserted between a bearing 12 and the spring 7 and thereby an original pressing force is restored easily. According to this constitution, the measuring accuracy of the vibration indicator 21 can be maintained for a long period.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrometer probe device for inducing vibration of a main shaft to the outside and detecting it by a vibrometer in a turbine generator.

[0002]

2. Description of the Related Art Generally, a vibrometer for measuring turbine shaft vibration in a turbine generator is mounted via a vibrometer probe and tilted in a range of θ = 30 ° to 45 ° from a vertical position with respect to the turbine shaft. It is common to secure the vibrometer probe to the casing of the turbine body.

Alternatively, the vibrometer probe has a contactor at one end,
It consists of a shaft with a threaded part for attaching a vibrometer to the other end, a protective cylinder for holding the shaft, and a coil spring. The shaft is movably supported by bearings at both ends of the protective cylinder. ing.

In the case of this conventional vibrometer probe, the protective cylinder has an open structure, and is designed and manufactured so that the pressing force of the contactor becomes a specified value when it is attached to the turbine generator. For this reason, for example, when the contactor wears, it shortens and the spring expands by that amount, reducing the pressing force and causing inconveniences such as measurement being impossible.Therefore, it is necessary to stop the turbine and replace it with a new contactor. was there.

[0005]

If the pressure of the spring can be easily adjusted from the outside of the probe, the turbine can be stopped by correcting the pressure from the outside when the above-mentioned inconvenience occurs. Instead, stable measurement is possible over a long period of time.

According to the present invention, the bearing portion on the upper part of the probe and the protective cylinder are screwed together, and the bearing portion is moved relative to the protective cylinder and the pressure of the spring can be changed by rotating the bearing portion from the outside. The purpose of the present invention is to provide a vibrometer probe device.

[0007]

A vibrometer probe device according to the present invention comprises a contactor mounted in contact with a rotating body to detect vibration of the rotating body, and a contactor attached to one end of the vibrometer. The shaft to mount, the protective tube that houses the shaft and supports the shaft by the bearings at both ends to allow the shaft to move in the axial direction, the flange provided at the intermediate part of the shaft, and the shaft inside the protective tube. The coil spring is placed between the coil spring and the upper end of the protective cylinder, and the coil spring is arranged vertically between the coil spring and the shaft. It is characterized in that it is provided with a compression ring for expanding and contracting.

Further, the vibration probe device according to the second aspect is characterized in that the movement of the shaft in the axial direction is fixed by using a lock nut.

[0009]

In the vibrometer probe device of the present invention, the contact is attached to the rotating body to detect the vibration of the rotating body, the contact is attached to one end of the shaft, and the vibrometer is attached to the other end. , The shaft is housed in a protective tube, and the bearings at both ends enable the shaft to move in the axial direction,
A flange is provided in the middle part of the shaft, a coil spring is placed inside the protection cylinder and concentrically with the shaft outside the shaft, and the lower end is placed on the flange, and between the coil spring and the upper end in the protection cylinder. It is characterized in that the coil spring is expanded and contracted in the vertical direction by installing a pressure ring and introducing gas into the inside.

The probe device according to a second aspect is characterized in that the movement of the shaft in the axial direction is fixed by using a lock nut.

[0011]

EXAMPLE An example of the vibrometer probe device of the present invention will be described below. In FIG. 1, the contactor 3 is a vibration detection terminal for detecting the vibration of the rotary moving body attached in contact with the rotary moving body. The shaft 2 is a shaft on which the contactor 3 is attached to one end and the vibrometer 21 is attached to the other end. The protective cylinder 1 accommodates the shaft 2 and supports the shaft 2 by means of bearing portions 5 and 12 at both ends thereof to allow the shaft 2 to move in the axial direction. The flange 8 is provided at an intermediate portion of the shaft 2 to prevent lateral deflection of the shaft 2 and also serves as a fixture for stopping the coil spring 7. The coil spring 7 is disposed inside the protective cylinder 1 and concentrically with the shaft 2 on the outer side of the shaft 2, and a lower end portion thereof is placed on the flange 8 to adjust the axial movement of the shaft 2 together with the flange 8. The pressure ring 31 is a volume ratio changing tool that is installed between the coil spring 7 and the upper end of the protective cylinder 1 to expand and contract the coil spring 7 in the vertical direction by introducing gas into the inside.

That is, the probe shown in FIG. 1 has a contact 3 at one end and a screw portion 4 for attaching the vibrometer 21 at the other end. It comprises a shaft 2, a protective cylinder 1 for holding the shaft 2, a coil spring 7, and an upper bearing 12, and the shaft 2 moves axially by a lower bearing portion 5 of the protective cylinder 1 and an upper bearing 12. It is supported as much as possible. The coil spring 7 is concentrically arranged on the outer side of the shaft 2 in the protective cylinder 1, one end of which abuts on the lower surface of the bearing 12, and the other end of which abuts on the upper surface of a flange 8 provided in the space portion of the shaft 2. ing. Further, a screw 9 is provided on the outer circumference of the upper bearing 12, and a screw 10 is provided on the inner surface of the upper end of the protective cylinder 1. The protective cylinder 1 and the bearing 12 are connected by these screws 9, 10. There is.

The vibration probe constructed as described above is illustrated with the positional relationship between the shaft 2 and the protective cylinder 1 maintained so that the shaft 2 is constantly pressed against the turbine shaft (not shown) by the coil spring 7. Not mounted on the casing of the turbine body. Thereby, the vibration of the turbine shaft can be faithfully transmitted to the vibrometer 21 via the shaft 2. Further, when the contactor 3 is worn by sliding on the turbine shaft, the spring 7 expands, and when the pressing force decreases, the bearing 12 is rotated and screwed downward to press the expanded spring 7, The original pressing force can be easily restored.

The purpose of the vibration probe is to accurately transmit the vibration of the turbine shaft to the vibrometer, depending on its application. However, due to the pressing by the spring, the limit condition that the spring does not follow when the vibration exceeds a certain condition is shown by the following equation.

[0015]

[Equation 1] Here, f _s is the limit vibration frequency (H _z ) and f _p is the free vibration frequency (H _z ) of the probe.

Further, x _m is an initial displacement (mm) related to the pressure applied to the spring, Δx is an amplitude (displacement) of vibration (mm), and f _p is an eigenvalue of the probe. From the above equation, when the amplitude value of the vibration to be measured is constant, the measurement limit frequency changes due to the initial displacement (pressing) of the spring.
The higher the initial displacement (pressure), the wider the measurable range. However, if the pressure is increased, the wear of the contactor 3 is affected, and therefore it cannot be increased unnecessarily.

From the above situation, it is possible to change the pressing force of the spring to obtain the above results.

(1) When the contactor is worn, the spring is stretched by the amount of wear and the initial pressing force x _m is reduced, and the limit frequency is lowered. With the conventional probe, is the probe removed from the turbine once and the contactor is converted? Or, it was necessary to shift the mounting position (shift the position of the protective cylinder) and re-mount so that the pressing was in the original state. However, with this method,
The pressure can be easily returned (increased) even with the turbine operation width.

(2) When there is vibration exceeding the limit frequency in the turbine operating width, even if the wear of the contact is a little faster, when measuring the vibration, the upper bearing from the outside is used.
By turning 12, the pressure can be easily changed and high frequency vibration can be measured, which is useful for investigating the cause of turbine vibration. Conventionally, it has been necessary to change the operating conditions of the turbine to suppress vibration and operate the turbine.

FIG. 2 shows an embodiment of claim 2 in which a lock nut 11 is added. In the case of FIG. 1, the purpose is to prevent the upper bearing from rotating due to vibration and the pressure naturally changing.

In FIG. 3, between the upper bearing 12 and the spring 7, there is a doughnut-shaped (double cylinder) inlet 32 for introducing air pressure inside. The pressure ring 31 is inserted. FIG. 4 is a perspective view of the pressure ring 31.

The pressure of the spring can be changed by changing the pressure of the air introduced into the pressure ring 31.

FIG. 5 shows an air spring 41 instead of the spring 7.
Is used. The air spring 41 shown in FIG. 6 is a double cylinder in which gas is enclosed, and can be expanded and contracted by applying a force in the vertical direction. As the amount of contraction increases, the internal volume decreases, and the repulsive force (pressing force when used in the vibration probe) increases. By using this air spring and performing a predetermined attachment, the vibration of the turbine shaft can be transmitted to the vibrometer.

FIG. 7 is a modification of FIG. 6, in which gas is introduced into the air spring 41. It has an inlet 42, and the pressure can be easily changed by changing the pressure of the introduced gas 43 even in the operating width.

[0025]

According to the present invention, the measurement accuracy of the vibrometer can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a vibration probe according to an embodiment of the present invention.

FIG. 2 is a partial sectional view showing another embodiment.

FIG. 3 is a cross-sectional view of an embodiment in which air pressure is used to change the spring pressure.

FIG. 4 is a perspective view of a pressure ring.

FIG. 5 is a cross-sectional view showing an embodiment of a vibration probe using an air spring.

FIG. 6 is a perspective view of an air spring.

FIG. 7 is a sectional view showing another embodiment.

[Explanation of symbols]

 1 ... Protective cylinder 2 ... Shaft 3 ... Contact 5 ... Bearing 7 ... Coil spring 8 ... Flange 21 ... Vibrometer

Claims (2)

[Claims] 1. A contactor mounted in contact with a rotating body to detect vibration of the rotating body, a shaft to which the contactor is attached to one end and a vibrometer to the other end, and both ends accommodating the shaft. With a bearing portion of the shaft that supports the shaft so that the shaft can move in the axial direction, a flange provided in an intermediate portion of the shaft, and the shaft outside the shaft inside the protection cylinder. A coil spring that is concentrically arranged and has its lower end placed on the flange, and is installed between the coil spring and the upper end of the protective cylinder to introduce gas into the coil spring so that the coil spring moves vertically. A vibrometer probe device comprising: a compression ring that expands and contracts. 2. The lock nut is used to fix the movement of the shaft in the axial direction.
The vibration probe device described in 1.