JP2000002781A - Motor with control brake for control rod drive mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust a zero point without removing a control rod drive motor unit or the like by releasing a brake for a motor with a brake in a control rod drive mechanism, using operation different from that for the motor. SOLUTION: This, motor for a control rod drive mechanism 1 is a motor 34 with control brake 35 (a combined set 33) of a nonexciting operation type using commonly a three-phase power source of a drive source for the control rod mechanism 1 for controlling the output of a nuclear reactor, and is provided with a brake spring 26 for the brake 35 and a gap adjusting bolt 38 to release the brake 35 by removing them, and is provided detachably with a manual adjustment handle 42 connected to a motor rotary shaft 36 to rotate the motor 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive source for a control rod drive mechanism of an improved boiling water reactor, and more particularly, to a control rod drive mechanism which integrates an electric motor and a brake for easy control rod manual adjustment. The present invention relates to an electric motor with a brake for braking.

[0002]

2. Description of the Related Art A control rod drive mechanism used in an improved boiling water reactor controls the reactivity of a reactor by inserting or removing a control rod connected to an upper end into or out of a reactor core. It is a device that is particularly important for the operation and safety of a nuclear power plant.

As shown in FIG. 8, a control rod drive mechanism 1 is provided at a lower end of a control rod drive mechanism 1 as a drive source during normal operation of a nuclear reactor. The control rod driving motor unit 2 is provided at the lowermost end with a motor 5 with a braking brake, in which a control rod driving motor 3 and a non-exciting operation type braking brake 4 are integrated.

Further, the electric motor 5 with a braking brake
In the casing 6 attached above the motor 3, the motor 3
Reducer 7 for reducing the rotation speed of the motor drive shaft in
And a holding brake 8 for holding a control rod (not shown) at an upper position at a stop position, and a synchro transmitter 9 for detecting the position of the control rod.

The control rod drive motor unit 2
A control rod drive shaft 11 by a ball screw is connected to the holding brake 8 via a coupling 10, and the control rod drive shaft 11 is rotated by the drive of the electric motor 3. The control rod is inserted into and pulled out of the core.

The motor 5 with a braking brake in the control rod drive motor unit 2 has a three-phase induction motor, and the braking brake 4 has a three-phase AC electromagnet, as shown in FIG. This is a disk-type non-excitation actuated brake that uses. Further, the power supply of the electric motor 3 and the braking brake 4 is shared by the same three-phase power supply 12, and the operation switch 15 provided in the middle of the cable 14 from the terminal block 13 allows the operation to be integrally cut off. Stop operation is being performed.

The brake lining 17 of the brake disk 16 of the braking brake 4 is connected to the electric motor rotating shaft 18 of the electric motor 3, so that it rotates together with the electric motor 3. The electromagnet 19 of the brake 4 is fixed to a brake frame 21 via fixing bolts 20.

A gap adjusting bolt 22 provided coaxially with the electric motor rotating shaft 18 allows a gap
Movable iron core 24 slidable in the axial direction with 23 open
A brake shoe 25 that comes into contact with the brake lining 17 is provided integrally with the brake lining 17. The movable iron core 24
The brake shoe 25 is pressed by the spring force of a brake spring 26 provided at the center of the electromagnet 19, whereby the brake shoe 25 comes into contact with the brake lining 17 to generate a braking force.

Further, by exciting the electromagnet 19, the attractive force of the electromagnet 19 to the movable iron core 24 overcomes the spring force of the brake spring 26, and the movable iron core 24 is attracted to the electromagnet 19 and the gap 23 is closed. Since the brake shoe 25 is separated from the brake lining 17, the braking force is lost. The gap 23 can also be tightened by tightening the gap adjusting bolt 22.
To zero to release the brake.

That is, the brake 4 is released when the operation switch 15 is turned on, and the operation switch 15 is turned off.
Doing so will apply the brakes. Therefore, the operation switch 15
When the three-phase power supply 12 is supplied to the electric motor 5 with the braking brake, a driving torque is generated on the electric motor 3 side. on the other hand,
On the braking brake 4 side, the electromagnet 19 is excited to lose the braking force, and the electric motor 3 rotates together with the brake lining 17.

Conversely, when the power is turned off by the operation switch 15,
On the motor 3 side, the driving torque is lost and only the inertia is present. On the other hand, on the braking brake 4 side, the electromagnet 19 is de-energized and the attraction force is lost, so the brake shoe 25 presses the brake lining 17 and the braking force , The electric motor 3 stops rapidly.

In the control rod drive mechanism 1, the zero adjustment is performed by the control rod manual adjustment at an appropriate time. The zero adjustment by the manual adjustment of the control rod is a reference position for causing the control rod monitoring system including the synchro transmitter 9 to accurately recognize the position (correct position) of the control rod in the core. This requires that the adjustment be made with high accuracy.

The control rod driving mechanism 1 is always mounted when the control rod driving motor unit 2 is mounted on the control rod driving mechanism 1 and when the reference position setting is reset due to an abnormality of the control rod monitoring system. .

In order to perform the zero adjustment of the position of the control rod accurately and reliably, as shown in the control rod movement range diagram of FIG. 10, first, the exact position of the control rod can be grasped and the control rod is being adjusted. To prevent the control rod drive mechanism 1 from shifting. To this end, the control rod is previously lowered to the mechanical minimum position 27 in the control rod movable range 29 by the mechanical minimum position 27 and the mechanical maximum position 28 by control rod movement, and this position is A zero position "0" is recognized by a control panel (not shown) in the control rod monitoring system so as to be a reference point.

However, the mechanical lowermost position 27 is a position where movement of the control rod drive mechanism 1 is physically impossible if each part of the control rod drive mechanism 1 is in a healthy state. Control rod withdrawal position
Control rod normal operation range 32 with 30 and all control rod insertion positions 31
The control rod is located further below the lowermost point of the control rod full withdrawal position 30.

Thus, the zero adjustment of the conventional control rod is performed by lowering the control rod to the control rod full withdrawal position 30 by driving the electric motor 3 from the structure of the control rod drive motor unit 2, After removing the control rod drive motor unit 2 from the drive mechanism 1, it was necessary to manually rotate the control rod drive shaft 11 to lower the control rod to the mechanical lowermost position 27.

Next, a description will be given of a work process of zero adjustment for a conventional general control rod. 1. By driving the electric motor 3, the control rod is moved to the full withdrawal position 30 in the normal operation range 32. 2. A work scaffold is temporarily provided below the control rod drive mechanism 1. 3. After the operation switch 15 is turned off, the cable 14 is removed on the work platform.

4. The control rod drive motor unit 2 is removed by the control rod drive mechanism handling device. 5. By manually operating the control rod drive shaft 11, the control rod is lowered to the mechanical lowermost position 27. 6. The control rod drive motor unit 2 is mounted by the control rod drive mechanism handling device.

[7] Attach the cable 14 on the work scaffold. 8. Remove temporary work scaffolds. 9. The position data of the control rod is input to the control panel of the control rod monitoring system. Ten. The operation switch 15 is turned on to drive the electric motor 3, and the position of the control rod is moved to within the normal operation range 32.

[0020]

In the above-mentioned work process for control rod zero adjustment, items 2 to 8 are work in the lower drywell of the reactor containment vessel which is a radiation control area. Items 6 and 7 are the control rod drive mechanism 1
This is an operation related to the attachment and detachment of the control rod drive motor unit 2 with respect to FIG. Therefore, these various operations in the nuclear reactor require an enormous amount of work due to the quantity of the control rod drive mechanism 1, and therefore, it takes a long time even if the control rod drive mechanism handling device is used. Therefore, sufficient exposure control is required, and there is a problem that work efficiency is low.

An object of the present invention is to release the braking brake of the electric motor with the braking brake by a separate operation from the electric motor, and without removing the control rod driving motor unit or the like from the control rod driving mechanism. An object of the present invention is to provide an electric motor with a brake for a control rod drive mechanism that can easily adjust a zero point.

[0022]

According to a first aspect of the present invention, there is provided an electric motor with a brake for a control rod driving mechanism, the driving source of the control rod driving mechanism for controlling the output of a nuclear reactor. In the electric motor with a braking brake of the non-excitation operation type which is shared by the three-phase power supply, the brake can be released by removing the brake spring and the gap adjusting bolt of the braking brake, and the motor is connected to the rotating shaft of the electric motor when the brake is released. And a manual adjustment handle for rotating the electric motor is detachably provided.

When the motor is stopped, the brake is released by removing the gap adjusting bolt together with the brake spring. Thereby, a manual adjustment handle is attached to a portion of the braking brake from which the brake spring and the gap adjustment bolt have been removed, and connected to the electric motor rotating shaft,
By manually rotating the motor, the control rod zero point can be adjusted.

According to a second aspect of the present invention, there is provided an electric motor with a brake for a control rod driving mechanism according to the first aspect of the present invention.
The electric motor with a braking brake is provided with a brake spring of the braking brake releasably provided by a gap adjusting bolt, and a manually adjustable handle for connecting the electric motor rotating shaft and rotating the electric motor when the brake is released is detachably provided. It is characterized by.

With the motor stopped, the brake is released by tightening the gap adjustment bolt. Thus, the manual adjustment handle is attached to the braking brake, connected to the rotating shaft of the electric motor, and the electric motor is rotated manually to perform the control rod zero adjustment.

According to a third aspect of the present invention, there is provided an electric motor with a braking brake for a control rod driving mechanism according to the first or second aspect, wherein the electric motor with the braking brake connects the motor rotating shaft to the outer end of the braking brake. And a manual adjustment handle for rotating the motor in connection with the motor rotation shaft when the brake is released is detachably provided.

With the motor stopped, the brake is released by tightening the gap adjustment bolt. Thus, the manual adjustment handle is connected to the motor rotating shaft extended to the outer end of the braking brake, and the control rod zero can be adjusted by manually rotating the motor.

According to a fourth aspect of the present invention, there is provided an electric motor with a brake for a control rod driving mechanism according to the first to third aspects, wherein a switch for disconnecting the electric motor is provided in the electric motor side circuit. .

When the switch for disconnecting the motor provided in the motor-side circuit is turned off, the motor is disconnected from the power supply circuit. For this reason, when the power switch is turned on, the motor is stopped, but the braking brake is released. As a result, the manual adjustment handle is attached to the braking brake,
The control rod zero can be adjusted by manually rotating the motor in connection with the motor rotating shaft.

According to a fifth aspect of the present invention, there is provided an electric motor with a brake for a control rod drive mechanism according to the first to third aspects, wherein a circuit disconnecting connector is provided in the electric motor side circuit. .

The motor is disconnected from the power supply circuit by disconnecting the circuit disconnecting connector provided in the motor-side circuit. For this reason, when the operation switch is turned on, the electric motor is stopped, but the braking brake is released. As a result, the manual adjustment handle is attached to the braking brake,
The control rod zero can be adjusted by manually rotating the motor in connection with the motor rotating shaft.

According to a sixth aspect of the present invention, in the electric motor with a braking brake for a control rod drive mechanism according to the first to third aspects, the braking brake is a single-phase excitation type and is connected to the three-phase power supply circuit. It is characterized by the following. Since the three-phase motor is shared with the three-phase motor and the single-phase excitation braking brake are connected, the motor rotates when the three-phase power is supplied, and the braking brake is released at the same time.

However, if a single phase is supplied from the power supply while the motor is stopped, or three phases are supplied while one phase of the motor side circuit is disconnected, the motor is stopped without starting because no rotating magnetic field is generated. It remains in the state, but the braking brake is released. Thus, the manual adjustment handle is attached to the braking brake, connected to the rotating shaft of the electric motor, and the electric motor is rotated manually to perform the control rod zero adjustment.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. The same components as those of the above-described conventional technology are denoted by the same reference numerals, and detailed description is omitted. In the first embodiment, as shown in a vertical sectional view of FIG. 1, an electric motor 33 with a braking brake for a control rod drive mechanism is used.
The motor 34 includes a motor 34 and a braking brake 35. A coupling portion 37 having, for example, a hexagonal hole is provided at a tip of the motor 34 on the brake side of the motor rotating shaft 36.

In the braking brake 35,
The gap adjusting bolt 38 is loosened and turned 90 degrees, and is detached from the movable core 24 at a locking portion 38 a detachably formed at the tip thereof from the movable iron core 24, and is taken out together with the brake spring 26 by a mounting screw 39. Thus, the brake is released regardless of whether the movable core 24 is excited or not.

Further, in the brake released state in which the brake spring 26 and the gap adjusting bolt 38 are removed, as shown in a vertical sectional view of FIG. In the middle of the bearing 40
The manual adjustment handle 42 provided with the support portion 41 is configured to be attachable by a mounting screw 39 instead of the gap adjustment bolt 38 of the braking brake 35. The shape of the coupling portion 37 of the electric motor rotating shaft 36 and the shape of the manual adjustment handle 42 can be any shape depending on the surrounding conditions and functions.

Next, the operation of the above configuration will be described. When the operation switch 15 is turned on, the control rod driving mechanism 1 is driven by the three-phase power supply 12, and the braking brake 35 of the electric motor 33 with a braking brake for the control rod driving mechanism turns the movable iron core 24 when the electromagnet 19 is excited. The gap 23 becomes zero against the spring force of the brake spring 26. Thus, the brake is released and the electric motor 34 is operated, so that the control rod is inserted or pulled out via the control rod drive shaft 11.

For manual control rod zero adjustment in the control rod drive mechanism 1, first, the operation switch 15 is turned on to move the control rod to the full withdrawal position 30 in the normal operation range 32, and the control rod drive mechanism 1 A temporary work scaffold will be installed at the bottom of the building.

Next, when the operation switch 15 is turned off and the three-phase power supply 12 is turned off, the driving force of the electric motor 34 disappears and the attraction force of the electromagnet 19 on the movable iron core 24 also disappears. Therefore, the gap 23 is opened by the spring force of the brake spring 26, and the brake shoe 25 is
Since the braking force is generated by pressing the button 17, the electric motor 3 stops rapidly and the operation of inserting or removing the control rod stops.

Next, when the gap adjusting bolt 38 of the braking brake 35 is turned by 90 degrees on the working scaffold, the gap adjusting bolt 38 is disengaged from the movable iron core 24 at the locking portion 38a at the tip thereof, and the mounting screw 39 is further removed. When the gap adjusting bolt 38 is removed together with the brake spring 26, the braking brake 35 is released.

In the released state of the braking brake 35, as shown in FIG.
The manual adjustment handle 42, which is a hexagon connected to the connecting portion 37 of the
Attach to 35. The manual adjustment handle 42 has its tip connected to the coupling portion 37 of the electric motor rotating shaft 36, and temporarily attaches the support portion 41 to the braking brake 35 with the mounting screw 39. By rotating, the electric motor 34 can be easily rotated.

Thus, according to the motor 33 with a braking brake for the control rod drive mechanism, the control rod (not shown) can be easily controlled via the control rod drive shaft 11 by rotating the motor 34 with the manual adjustment handle 42. And the insertion or withdrawal operation can be performed depending on the rotation direction.

Therefore, without removing the control rod drive motor unit 2 from the control rod drive mechanism 1, the position of the control rod can be manually adjusted by the manual adjustment handle 42 to the mechanical lowermost position 27 in the control rod movable range 29. Can be adjusted.
After this, remove the mounting screw 39 and remove the manual adjustment handle.
Remove 42 from the brake 35 and replace the mounting screws
According to 39, when the gap adjusting bolt 38 is mounted together with the brake spring 26, a braking force is generated by the brake 35.

Next, by rotating the gap adjusting bolt 38 by 90 degrees, the engaging portion 38a at the tip thereof is brought into engagement with the movable iron core 24, thereby returning to the normal state as shown in FIG. 1 again. , Remove the work scaffold. The result of the zero adjustment with the control rod as the mechanical lowermost position 27 is input to the control panel of the control rod monitoring system as position data.

After the control rod zero adjustment is completed, the operation switch 15 is turned on to drive the motor 33 with a braking brake for the control rod driving mechanism, and the position of the control rod is inserted into the normal operation range 31. Then, the operation of control rod zero adjustment is completed.

Accordingly, the work of adjusting the control rod zero point by the motor 33 with the brake for the control rod drive mechanism is performed only by temporarily setting the work scaffold, and the work of detaching and attaching the cable 14 and the handling apparatus of the control rod drive mechanism are performed. No need to use,
Because the process is greatly reduced and the work is simple,
Since fewer workers are required and the work time is shortened, work efficiency is improved and radiation exposure is reduced.

Further, in addition to the control rod zero adjustment operation, a torque mail is attached to the manual adjustment handle 42 or the electric motor rotating shaft 36 so that the control rod drive mechanism 1 can be used to control the control rod drive motor unit 2 or the brake for braking. The functions of the holding brake 8 and the braking brake 35 can be checked without removing the electric motor 33. The electric motor 34
Since the load torque and the like of the control rod driving mechanism 1 as viewed from the side can be easily measured, the reliability is improved by managing the functions of a large number of control rod driving mechanisms 1.

Since the second embodiment is a modification of the first embodiment according to the second aspect, the same components, operations and effects as those of the first embodiment will be described in detail. Are omitted, and different parts will be described. FIG.
As shown in the vertical sectional view of FIG. 5, the electric motor 43 with a braking brake for the control rod drive mechanism includes an electric motor 34 and a braking brake 44. In the braking brake 44, a gap adjusting bolt 45 and a brake spring 46 are provided. Are arranged on the outer peripheral portion of the movable iron core 24.

The gap 23 between the electromagnet 19 and the movable core 24 is reduced to zero by tightening the gap adjusting bolt 45, so that the magnet 23 can be driven regardless of whether it is excited or not.
Further, the brake can be released without removing the components such as the brake spring 46. The other configuration is the same as that of the first embodiment.

Next, a description will be given of a method of releasing the braking brake 44 in the control rod zero adjustment as an operation of the above configuration. When the three-phase power supply 12 is turned off by turning off the operation switch 15 (not shown), the driving force of the electric motor 34 is lost,
The attractive force of the electromagnet 19 on the movable core 24 is also eliminated.

Accordingly, the gap 23 is opened by the spring force of the brake spring 46, and the brake shoe 25 presses the brake lining 17, so that the electric motor 34 is stopped quickly and the operation of inserting or removing the control rod is stopped. Here, the gap adjusting bolt 45 of the braking brake 44
By tightening, the gap 23 becomes zero, so the brake shoe 25 is separated from the brake lining 17,
The braking brake 44 is released.

Next, the tip of the manual adjustment handle 42 is connected to the connecting portion 37 of the electric motor rotating shaft 36, and the supporting portion 41 is attached with the mounting screw 39.
By temporarily attaching the brake to the brake 44, the operator can rotate the manual adjustment handle 42 to easily rotate the electric motor 34.

Thus, according to the motor 43 with a braking brake for the control rod drive mechanism, the brake is released without removing the gap adjusting bolt 45 and the brake spring 46, and the motor rotating shaft 36 is rotated by the manual adjusting handle 42. By rotating the control rod, a control rod (not shown) can be easily driven via the control rod drive shaft 11, and insertion or pull-out operation can be performed according to the rotation direction.

Since the third embodiment is a modification of the second embodiment according to the third aspect, the same components, operations and effects as those of the second embodiment and the first embodiment are provided. For, the detailed description is omitted, and different parts will be described.

As shown in the longitudinal sectional view of FIG. 4, the motor 47 with a brake for a control rod drive mechanism comprises an electric motor 48 and a brake 44, and the brake 44 has a gap adjusting bolt. 45 and brake spring 46
Are arranged on the outer peripheral portion of the movable iron core 24. Also, tightening the gap adjustment bolt 45 causes the electromagnet 19
By setting the gap 23 between the
The brake can be released regardless of excitation or non-excitation in 24.

Further, the electric motor rotating shaft 49 of the electric motor 48 is extended, and a gear-shaped coupling portion 50 is formed at the outer end through the braking brake 44 at the tip thereof. A manual adjustment handle 51 attached to the unit 50 and connected to the motor rotation shaft 49 is provided. The other configuration is the same as that of the second embodiment and the first embodiment.

Next, as a function of the above configuration, a method of releasing the brake 44 in the control rod zero adjustment will be described. When the three-phase power supply 12 is turned off by turning off the operation switch 15 (not shown), the driving force of the motor 48 is lost,
The attraction force of the electromagnet 19 to the movable iron core 24 also increases, and the spring force of the brake spring 46 causes the brake shoe 25
Presses the brake lining 17, and the braking force stops the electric motor 34 rapidly to stop the control rod insertion or withdrawal operation.

Here, by tightening the gap adjusting bolt 45 of the brake 44, the gap 23 becomes zero and the brake 44 is released. Next, the manual adjustment handle 51 is connected to the coupling portion 50 of the motor rotation shaft 49, and the operator can easily rotate the motor 48 by rotating the manual adjustment handle 51 by an operator.

Thus, according to the motor 47 with a braking brake for the control rod drive mechanism, it is not necessary to remove the gap adjusting bolt 45 and the brake spring 46, and to temporarily attach and detach the support 41, and manual adjustment is not required. Handle 51
Is easy to connect, and by rotating the motor rotating shaft 49,
A control rod (not shown) can be easily driven via the control rod drive shaft 11, and insertion or pull-out operation can be performed depending on the rotation direction.

Further, since the connecting portion 50 of the motor rotating shaft 49 is extended to the tip of the braking brake 44, the rotation of the motor 48 during normal operation and the rotation direction can be easily confirmed from outside. It is possible, and the reliability is improved together with the function management of the control rod drive mechanism 1.

The fourth embodiment is a method for releasing a braking brake by an electric circuit according to claim 4, which is a modification of the second and third embodiments, and is therefore a modification of the second embodiment. Detailed description of the same components, functions and effects as those of the embodiment and the third embodiment will be omitted,
The different parts will be described.

As shown in the circuit diagram of FIG. 5, taking the second embodiment as an example, the motor 43 with a brake for a control rod drive mechanism shown in FIG. In the braking brake 44, the gap adjusting bolt 45 and the brake spring 46 are arranged on the outer peripheral portion of the movable iron core 24.

Further, the gap 23 between the electromagnet 19 and the movable iron core 24 is reduced to zero by tightening the gap adjusting bolt 45, so that regardless of whether the movable iron core 24 is excited or not,
Brake can be released. The other configuration is the same as that of the first embodiment.

The connection of the three-phase power supply 12 of the power supply circuit to the electric motor 43 with the braking brake is performed via the operation switch 15, but the operation of the operation switch 15 is directly performed from the terminal box 13 in the braking brake 44. Connected to 15. However, the motor 34 is configured to be connected to the operation switch 15 via a three-pole switch 52 provided outside the terminal box 13 and disconnecting the motor.

Next, as a function of the above configuration, a method of releasing the brake 44 will be described. Operation switch
When the three-phase power supply 12 is turned off by turning off the power supply 15, the driving force of the electric motor 34 is lost, and the braking brake 44 stops the electric motor 34 suddenly by the braking force of the brake spring 46.

Here, when the triode switch 52 is turned off and the operation switch 15 is turned on again, the three-phase power supply 12 is applied only to the braking brake 44, and the motor 34 remains stopped to stop the braking brake. 44 is released. Thus, the electric motor 34 can be easily rotated by rotating the manual adjustment handle 42 connected to the electric motor rotating shaft 36.

Accordingly, the three-pole switch 52 is
By simply performing a simple switching operation, the motor 33 with the braking brake together with the braking brake 44 can be easily adjusted to the control rod zero point only by connecting and rotating the manual adjustment handle 42 without any modification. Can be. After the control rod zero point adjustment is completed, when the operation switch 15 is turned off, the electric motor 34 remains stopped, and the braking brake 44 generates a braking force.

Next, by turning on the three-pole switch 52, the normal standby state is restored.
By N and OFF, the control rod can be inserted or pulled out during normal operation. The motor 43 with a braking brake can obtain the same effect as the motor 47 with a braking brake shown in FIG. 4 of the third embodiment, and the motor with a braking brake of the first embodiment. Even if adopted in 33, the brake can be released by the same operation.

Further, the three-pole switch 52 supplies the three-phase power supply 12 to both the motor 34 and the brake 44 in the normal mode, isolates the motor 34 in the adjustment mode, and supplies the three-phase power only to the brake 44. The same function and effect as described above can be obtained also with the function of supplying the power supply 12.

Since the fifth embodiment is a modification of the fourth embodiment according to the fifth aspect, the same components, operations and effects as those of the fourth embodiment are described.
Detailed description is omitted, and different portions will be described.

As shown in the circuit diagram of FIG. 6, taking the second embodiment as an example, the motor 43 with a braking brake for a control rod drive mechanism shown in FIG. In the braking brake 44, the brake can be released by tightening the gap adjusting bolt 45 regardless of whether the movable core 24 is excited or not. The other configuration is the same as that of the first embodiment.

The connection of the three-phase power supply 12 to the electric motor 43 with the braking brake is performed via the operation switch 15.
It is directly connected to the operation switch 15. But electric motor
34 is configured to be connected to the operation switch 15 via a three-pole connector 53 which is a connector for disconnecting a circuit provided at a branching point with the braking brake 44 or the like.

Next, as a function of the above configuration, a method of releasing the braking brake 44 will be described. Operation switch
When the three-phase power supply 12 is turned off by turning off the power supply 15, the driving force of the electric motor 34 is lost, and the braking brake 44 is suddenly stopped by the braking force of the brake spring 46.

Here, when the three-pole connector 53 is disconnected and the operation switch 15 is turned on again, the three-phase power supply 12 is applied only to the braking brake 44, and the electric motor 34 is stopped and the braking brake 44 Is released. Accordingly, the manual adjustment handle 42 connected to the motor rotating shaft 36 can be rotated, and the motor 34 can be easily rotated.

Therefore, the three-pole connector 53 is connected to the circuit on the motor side.
With a simple disconnection operation, the brake rod 44 and the electric motor 33 with the braking brake can be easily adjusted by simply connecting and rotating the manual adjustment handle 42 without any modification. Can be.

Since the sixth embodiment is a modification of the fourth embodiment according to the sixth aspect, the same components, operations and effects as those of the fourth embodiment are described.
Detailed description is omitted, and different portions will be described. As shown in the circuit diagram of FIG. 7, the motor 54 with a braking brake for the control rod drive mechanism comprises a three-phase motor 34 and a single-phase excitation type single-phase braking brake 55. The brake 55 is a disk-type non-excitation operation type brake using a single-phase AC electromagnet.

The structure is the same as that shown in FIG. 3 of the second embodiment, and the brake is released by tightening the gap adjusting bolt 45 regardless of whether the movable core 24 is excited or not. be able to. The other configuration is the same as that of the first embodiment.

The connection of the three-phase power supply 12 to the electric motor 54 with the braking brake is performed via the operation switch 15.
Is directly connected to the operation switch 15. However, the motor 34 is connected to the operation switch 15 via a single-pole switch or a single-pole disconnector 56 such as a single-pole connector outside the terminal box 13, for example.

In addition, when the single-pole disconnector 56 is not provided in the motor side circuit and the motor 34 is stopped to release the single-phase braking brake 55 by adjusting the zero point of the control rod, etc. Instead of the three-phase power supply 12, a single-phase power supply (not shown) is connected to the operation switch 15.

Next, as a function of the above configuration, a method of releasing the single-phase braking brake 55 will be described. When the operation switch 15 is turned off and the three-phase power supply 12 is turned off, the driving force of the electric motor 34 is lost, and the single-phase braking brake 55 loses the excitation of the electromagnet by the single-phase component from the three-phase power supply 12.
A braking force is generated by the spring force of the brake spring 46, and the electric motor 34 is suddenly stopped.

When the operation switch 15 is turned on again after disconnecting the single-pole disconnector 65, the motor 34 receives only a single-phase component from the three-phase power supply 12, so that a starting torque is generated. The three-phase braking brake 55 is released because the electromagnet is excited by the single-phase component from the three-phase power supply 12 because there is no stop. Thereby, the manual adjustment handle 42 connected to the electric motor rotating shaft 36 is rotated,
The electric motor 34 can be easily rotated.

Accordingly, by simply inserting the single-pole disconnector 65 into one phase of the three-phase motor 34 and performing a simple disconnection operation, the motor 54 with the brake for braking together with the brake 55 for single-phase braking is manually operated. The control rod zero can be easily adjusted by connecting and rotating the manual adjustment handle 42 without adding the control rod.

Further, when the single-pole disconnector 56 is not provided in the motor-side circuit, and the single-phase braking brake 55 is released when the motor 34 is stopped, a single-phase power supply 12 is used instead of the three-phase power supply 12. The phase power is supplied via the operation switch 15. Also in this case, the three-phase electric motor 34 does not start with the single-phase power supply and remains stopped, but the single-phase braking brake 55 is released by excitation with the single-phase power supply.

The motor 54 with a braking brake has the same effect as that of the motor with a braking brake 47 of the third embodiment shown in FIG. 4 except for the single-phase braking brake 55. Even if it is adopted in the electric motor 33 with a braking brake of the first embodiment, the brake can be released by the same operation.

[0085]

As described above, according to the present invention, the operation of releasing the braking brake can be easily performed without removing the control rod driving motor unit or the electric motor with the braking brake from the control rod driving mechanism. As a result, it is easy to adjust the control rod zero point and check various functions of the control rod drive mechanism, improving the reliability and eliminating the need to attach and detach the control rod drive mechanism handling device and control rod drive motor unit during work. By shortening the work process and reducing the number of workers, work efficiency is improved and radiation exposure is reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an electric motor with a braking brake for a control rod drive mechanism according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view at the time of manual adjustment of the first embodiment according to the present invention.

FIG. 3 is a longitudinal sectional view of a motor with a braking brake according to a second embodiment of the present invention at the time of manual adjustment.

FIG. 4 is a longitudinal sectional view of a motor with a braking brake according to a third embodiment of the present invention at the time of manual adjustment.

FIG. 5 is a circuit configuration diagram of an electric motor with a braking brake according to a fourth embodiment of the present invention.

FIG. 6 is a circuit configuration diagram of an electric motor with a braking brake according to a fifth embodiment of the present invention.

FIG. 7 is a circuit configuration diagram of an electric motor with a braking brake according to a sixth embodiment of the present invention.

FIG. 8 is a configuration diagram of a part of a control rod driving mechanism with a part cut away.

FIG. 9 is a longitudinal sectional view of a conventional electric motor with a braking brake for a control rod drive mechanism.

FIG. 10 is a control rod moving range diagram.

[Explanation of symbols]

1. Control rod drive mechanism 2. Control rod drive motor unit
3,34,48… Electric motor, 4,35,44… Brake for braking,
5, 33, 43, 47, 54 ... electric motor with brake for braking, 6 ...
Casing, 7: Reduction gear, 8: Holding brake, 9: Synchro transmitter, 10: Coupling, 11: Control rod drive shaft,
12 ... three-phase power supply, 13 ... terminal block, 14 ... cable, 15 ... operation switch, 16 ... brake disc part, 17 ... brake lining, 18, 36, 49 ... electric motor rotating shaft, 19 ... electromagnet, 20 ... fixing bolt, 21 ... brake frame, 22, 38, 45 ... gap adjusting bolt, 23 ... gap, 24 ... movable iron core, 25 ... brake shoe, 26, 46 ... brake spring, 27 ... mechanical lower limit position, 28 ... mechanical upper limit Position, 29: Control rod movable range, 30: Control rod full withdrawal position, 31: Control rod full insertion position, 32: Control rod normal operation range, 37, 50: Coupling part, 38a ...
Locking part, 39: mounting screw, 40: bearing, 41: supporting part, 42,
51… Manual adjustment handle, 52… Tripolar switch, 53… Tripolar connector, 55… Single-phase braking brake, 56… Single-pole disconnector.

Claims (6)

[Claims] An electric motor with a non-excited operation type braking brake, which is a three-phase power supply and is a driving source of a control rod driving mechanism for controlling the output of a nuclear reactor, wherein a brake spring of the braking brake and a gap adjusting bolt are provided. A brake-equipped electric motor for a control rod drive mechanism, characterized in that a brake can be released by removing it and a manual adjustment handle for rotating the electric motor in connection with the electric motor rotating shaft when the brake is released is detachably provided. . 2. An electric motor with a braking brake, wherein a brake spring of the braking brake is provided so as to be releasable by a gap adjusting bolt, and a manual adjustment handle for connecting the motor rotating shaft to rotate the electric motor when the brake is released. 2. The electric motor with a brake for a control rod drive mechanism according to claim 1, wherein the electric motor is detachably provided. 3. The electric motor with a braking brake extends an electric motor rotating shaft to an outer end of the braking brake.
The electric motor with a brake for a control rod drive mechanism according to claim 1 or 2, further comprising a manually adjustable handle for connecting the electric motor rotating shaft to rotate the electric motor when the brake is released. 4. An electric motor with a brake for a control rod drive mechanism according to claim 1, wherein a switch for disconnecting the electric motor is provided in the electric motor side circuit in the electric motor with a brake for braking. . 5. The motor with a brake for a control rod drive mechanism according to claim 1, wherein the motor with a brake is provided with a connector for disconnecting the circuit in the motor side circuit. . 6. The control rod drive mechanism according to claim 1, wherein in the electric motor with a braking brake, the braking brake is a single-phase excitation type and is connected to the three-phase power supply circuit. Electric motor with brake for braking.