JPS6027942Y2 - vibration detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a contact-type vibration detector that detects vibrations of a rotating shaft.

In general, rotating shafts generate vibrations due to factors such as unbalanced weight and poor installation, resulting in various inconveniences such as generation of mechanical noise.

In particular, when the natural frequency matches the rotational speed, resonance occurs and this vibration state persists, producing a low humming sound and having an adverse effect on the load.

Therefore, it is necessary to promptly detect abnormal vibrations of the rotating shaft and take appropriate measures such as stopping the operation.

In this case, in large rotating electric machines such as turbine generators, contact type vibration detectors that directly detect vibrations on the rotating shaft are widely used.

Normally, this contact type vibration detector uses a mechanical vibration system consisting of an inertial body and a spring to create an apparently fixed point, and calculates the vibration amplitude from the relative displacement between this point and the vibration point. It is configured to measure electrically, and its tip is provided with a contact that comes into contact with the rotating shaft.

Conventionally, the contact surface of this contactor was formed into a flat shape as shown in Figure 1, so accurate vibration measurement was expected due to the deviation of the contact angle of the vibration detector and the rotational moment received from the rotating shaft. Can not do it.

In other words, if the contact 1 is set perpendicular to the axis O direction of the rotating shaft 2 as shown in FIG. .

However, as shown in FIG.
If it is set tilted by 01 degrees in the direction or if it is set tilted by 02 degrees in the axial direction as shown in Fig. 3,
Each contact part a/.

a'' is located at the end of the contactor 1' and forms a point contact.

In this state where the point contact is made at a position that is quite eccentric to the axis O, it is not possible to accurately detect vibrations in the axial direction of the rotor, and the point of contact is at the rotating shaft 2.
The installation state of the vibration detector becomes extremely unstable due to the rotational moment in the direction of rotation.

In this respect, even if the contact 1' is set accurately in the direction of the axis O as shown in Figure 1 (contact point a is on the axis O), it will be a line contact and will have a very large It receives rotational moment.

When actually setting up a vibration detector, it is very difficult to set it accurately as shown in Figure 1, and Figures 2 and 3
The states shown in the figure coexist.

When the contact 1' of the vibration detector is tilted and set in this way, a force is applied to rotate the contact 1' as described above, but normally spring pressure is applied to the contact 1'. When the spring pressure becomes stronger, it returns to its original position and repeats this situation.

In other words, irregular micro-vibrations are generated in the left-right direction around the contactor axis, and as a result, the irregular micro-vibrations are added to the vibrations of the rotating shaft 2, making it impossible to accurately detect the vibrations of the rotating shaft. It's gone.

The present invention has been devised in consideration of the above points, and provides a contact-type vibration detector that eliminates unstable detection conditions caused by tilting of the contactor, rotational moment received from the rotating shaft, etc.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the vibration detector according to the present invention, as shown in FIG. 4, a contactor 1 is formed with its tip (the contact surface with the rotating shaft 2) protruding into a spherical shape.

Therefore, if this contactor 1 is set perpendicular to the axis O direction of the rotating shaft 2 (Fig. 4) or if it is set tilted by mistake (Figs. 5 and 6), However, the contact with the rotating shaft 2 is a point contact (a contact point).

b', b'').

In this case, especially when the contact 1 is set perpendicular to the direction of the axis O (Fig. 4), the contact area is reduced compared to the conventional one (Fig. 1), so the rotation of the rotating shaft 2 causes The impact of this will be significantly reduced.

Furthermore, even if the contact 1 is tilted as shown in FIGS. 5 and 6, the contacts b' and b''
is always on the inside of the contact end, and the smaller the inclination, the more the contact b'.

b'' is closer to the center of the contact.

Therefore, the amount of lateral vibration is significantly reduced due to the rotational moment.

In this regard, in the conventional device, as shown in FIGS. 2 and 3, when there is an inclination, regardless of the degree of inclination of the contact 1', the contact points a', a'' are always located at the ends thereof. , and the lateral vibration is large due to the rotational moment.

Furthermore, as mentioned above, even if the contact 1 is set slightly tilted, the contact points b' and b'' are close to the center of the contact, so the vibration in the axial direction of the rotor 2 can be ensured in a stable state. can be detected.

As described above, the vibration detector according to the present invention is a contact-type vibration detector that directly detects the vibration of the rotating shaft, and the contact area with the rotor is minimized by making the contact surface of the contactor spherical. The contact point is always located near the center of the contact even if the contact is tilted slightly from the axis of the rotor.

Therefore, the excellent advantage is that it is possible to accurately detect vibrations in the axial direction of the rotary shaft by reducing the lateral vibration of the contactor caused by the rotation of the rotary shaft and eliminating the downwardly stable detection state caused by tilting. It has the following.

[Brief explanation of drawings]

1 to 3 are diagrams showing detection states by a conventional vibration detector, and FIGS. 4 to 6 are diagrams showing detection states by an embodiment of the present invention, respectively. 1.1'... Contact, 2... Rotating shaft.

Claims (1)

[Scope of utility model registration request] A contact-type vibration detector that directly detects vibrations of the rotating shaft by bringing a contact into contact with the rotating shaft, characterized in that the contact surface of the front track contactor is protruded into a spherical shape.