JPH0735843B2 - Vibration suppression station - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to vibration suppression of a rotating machine that moves at a low frequency with a large amplitude due to, for example, thermal linear expansion, in addition to vibration during operation due to imbalance of a rotating portion. Regarding stay device.

Prior art and problems to be solved by the invention These operating conditions are such that a so-called internal pump used to circulate the reactor water is placed inside the reactor vessel and the motor in the external motor housing is used as its drive shaft. It occurs in some nuclear power plants that are welded to the shaft that leads to it. As the pump and motor rotate, pulsating power is created due to the imbalance and vibrations in the motor housing. When the natural vibration coefficient of the motor housing is within the range where resonance with the motor speed can occur, the vibration amplitude of the motor housing is large enough to cause unacceptable stress to the fixture for mounting the motor housing to the reactor vessel. There is a risk of becoming. By providing the motor housing with a stay device that is fixed to the concrete shell of the reactor building, the natural vibration coefficient of the motor housing can be easily increased. However, the increase in pressure from a cold shutdown reactor to normal operating conditions and the movement of the motor housing due to thermal expansion of the reactor vessel causes stresses on the vessel fixtures that the fixed stays generally cannot tolerate. large.

Means and Actions for Solving Problems and Effects of the Invention According to the present invention, the above-mentioned drawbacks operate independently of each other and the stay is longitudinally moved when a compressive stress or tensile stress of a certain value or more is applied to the stay. This is overcome by providing the stay with first and second members configured to be deformable. The first member operates according to the friction principle and is adjusted to operate normally under lower force effects than the second member which includes a prestressed spring combination.

It is known that the vibration-inducing forces to be damped by the stays are small compared to static or low frequency forces caused by changes in motor housing and reactor pressure and temperature. Provide a stay with a friction joint that changes the stay longitudinally when subjected to a force that causes unacceptable stress to the stay and its fittings, but retains the rigidity of the stay when the force is as great as the vibration-inducing force. Thereby, the function of the stay can be guaranteed.

For example, as a precautionary measure against corrosion when friction forces become too great due to inaccurate settings, stays are provided with members that include prestressed springs. This member causes the stay to change longitudinally when subjected to a force that is somewhat above the force for properly setting the friction joint, but which stresses the stay and its fittings below an unacceptable value. However, if the member moves when the prestressing force of the spring is exceeded, most of the stabilizing effect of the stay will disappear. From this it is possible to check that the spring device has not been activated after the operating period. This can be done by providing it with an appropriately shaped seal.

Example Next, an example of the present invention shown in the drawings will be described.

In FIG. 1, 1 is an actual reactor vessel, and 2
Is a motor housing depending from the container 1.
It has a motor for the internal pump inside. A stay device 4 is applied between the motor housing 2 and the concrete shell 3 of the reactor building.

FIG. 2 shows a cross section DD of the stay 4. The stay 4 includes a first friction member 5 and a second overload member 6. The friction member 5 comprises two pawls 7 and 8 which are pressed against the tongue 10 by a cup spring 9, the tongue 10 being connected to one end of the stay 4 and provided with a friction lining 11. The setting of the friction member 5 is adjusted by tightening the bolt 12. In order to allow the pawls to easily move towards each other during setting and to obtain a large cross-sectional area, the pawls are provided with a longitudinal slot 14 which extends to an end plate 15 which holds the pawls together. A space 16 is provided inside the slotted portion of the pawl, and this space accommodates the overload member 6 and is provided inside the end plate. When the stay is stressed, the tongue piece 10 has the claws 7 and 8
Between them can be moved in the longitudinal direction of the stay.

The overload member 6 has an actuating rod 17, which is movable with respect to the stay 4 and passes through an opening in the end plate 15 and a space 16 and is fixedly connected to the other end of the stay. . The first cradle 18 operates in space 16
It is fixedly arranged at 17. Second and third pedestals 19 and 20 are arranged on both sides of the first pedestal 18, respectively.
The pedestals are fixedly connected to each other, but are configured to be movable in space 16 with respect to an actuation rod 17. In addition, a fourth cradle 21 is arranged such that it can move on the actuation rod 17 outside the second cradle 19 with respect to the first cradle 18. However, the pedestal 21 has an end plate 15
Alternatively, it is fixed to the wall of the space 16. In the rest position of the overload member 6, the pedestal 20 rests against the end plate 15 and the projection 22 of the operating rod 17. Cup springs 23 and 24 are respectively locked between the pedestals 19, 21 and 18, 20.

At both ends, the stay 4 is provided with spring-loaded ball joints 25 and 26 to ensure that longitudinal stay play is eliminated while at the same time reducing lateral stress. 3 to 5 show different cross sections in FIG. 2 by corresponding reference numerals.

The overload member 6 operates as follows. When the stay 4 experiences unacceptable tensile stress and the friction member 5 does not operate, the actuating rod 17 is retracted through the opening in the end plate 15 for the required length, thereby prestressing the spring. Is further compressed between pedestals 18 and 20. At this time, the pedestal
20 continues to contact the end plate 15 and the cradle 19 is cradle 20 and space 16
Since they are fixedly connected to the walls of the pedestals, the pedestals 21 and 19 do not move relative to each other and, as a result, the prestressed spring 23
Is not acted upon.

In the case of unacceptable compressive stress, actuating rod 17
Pushed through the opening in 15. This will activate the rod
The protrusion 22 of 17 pushes the pedestal 20 to the left in FIG. Since the cradle 20 is fixedly connected to the cradle 19, the cradle 20 also moves to the left,
Since the cradle 21 is fixedly connected to the end plate 15 and does not move,
The spring 23 between the pedestals 19 and 20 is compressed. From FIG. 2 it will be clear that in this case the spring 24 is not acted on, as the distance between the pedestals 18 and 20 remains the same. In this way, in the case of too high pressure and tensile stress,
Since no prestressed springs are released, a play-free overload protection device 6 is obtained.

[Brief description of drawings]

1 shows the lower part of a reactor vessel having a motor housing suspended in a reactor vessel provided with a stay device according to the invention, and FIGS. 2 to 5 show different cross sections of said stay device. . 1 ... Reactor vessel, 2 ... Motor housing, 3 ... Concrete shell, 4 ... Stay device, 5 ... First friction member, 6 ... Second overload member, 7,8 ... Claw , 9 ... Cup spring, 10 ... Tongue, 11 ... Friction lining, 12 ... Bolt, 14 ... Longitudinal slot, 15 ... End plate, 16 ... Space,
17 ... Actuating rod, 18 ... First cradle, 19 ... Second cradle, 20 ... Third cradle, 21 ... Fourth cradle, 22 ... Projection, 23, 24 …… Cup spring, 25, 26 …… Spring pressure ball joint.

Claims (4)

[Claims] 1. Fixed to a machine (2) or its analogue at one end and to a fixed point at the other end to increase the natural coefficient of vibration of the machine (2) or its analogue that vibrates during operation. In the stay device (4) arranged in such a manner, the first guide device (10) is provided at one end, the second guide device (17) is provided at the other end, and the housing (7,
8 and 15), and the first and second guide devices (1
0,17) is displaceable relative to the housing (7,8,15) along the longitudinal axis independently of the other guide device, and the first and second guide devices (10,17) ), A stay (4) that changes in the longitudinal direction when a compressive or tensile force exceeding a certain value is applied to the first guide device (10) and the housing (7, 8,
A friction member (11) for applying a frictional force between the second guide device (17) and the housing (7, 8,
15) and a spring member (23, 24) that gives an elastic force between the spring member and the elastic member so that the elastic member can be displaced from each other by the elastic force. One guide device (10) is displaced with respect to the housing (7, 8, 15), and the second guide device (17) is caused by the elastic force under the influence of the compressive force or the tensile force.
Is displaced with respect to the housing (7, 8, 15), and the second guide device (17) is
A stay device, characterized in that a force is applied to 15) to cause displacement between the first guide device (10) and the housing (7, 8, 15). 2. A pawl in which the friction member (11) is a friction lining around the first guide device (10), the first guide device (10) being loaded by a spring (9). (7,
Stay device according to claim 1, characterized in that it is provided in the housing (7, 8, 15) between 8). 3. The stay (4, 23) has at least first and second prestressed springs (24, 23) in the housing (7, 8, 15), the spring member (23, 24). When a tensile stress is applied to), the first spring member (24) is further compressed, but the second spring member (23) is not acted,
A second spring member (23) is further compressed when a compressive stress is applied to the stay (4), but the first spring member (24) is not acted upon. The stay device according to item 1. 4. The housing (7, 8, 15) is a space (1
6) and the second guiding device (17) has the space (1
6) having an actuating rod (17) displaceable with respect to the actuating rod (17) in the space (16) provided with a first cradle (18), the prestressed spring (24) ) Is provided between the first cradle (18) and the third cradle (20) on one side of the first cradle (18) along the longitudinal axis of the operating rod (17). And the third cradle (20) is fixed to the second cradle (19) on the other side of the first cradle (18), and the second and third cradle (19, 20) ) Is movable on the actuating rod (17), and the second prestressed spring (23) is fixed to the second cradle (19) and the space (16). It is movable between the pedestal (21) and the operating rod (17), and the third pedestal (20) at the stop position is located on the wall of the space (16) and the operating rod (17). On the protrusion (22) The stay device according to claim 3, wherein the stay device is configured to hit and stand still.