Actuating Mechanism of a System for the Control and Protection of a Nuclear Reactor

Abstract

Actuator of a nuclear reactor control and protection system comprises: a linear step motor comprising an armature; a rod being coaxial with and connected to the armature to enable joint vertical movement and rotation about a common vertical axis, which rod can form an L-shaped bayonet connection with a working member; and a lock to prevent spontaneous rotation of the rod. The lock comprises a guiding inside the armature and provided with a flange an longitudinal through slot; a cross-member connected to the armature, mounted in the slot and capable of vertical movement therein; a fixed ring, on which the inner surface of the flange rests; and a vertical pin. Through slots are arranged equidistantly in the outside rim of the flange, the vertical pin being mounted in one of several openings arranged equidistantly about the circumference of the fixed ring to pass through one of the through slots.

Claims

1. Actuating mechanism of a control and protection system of a nuclear reactor, including a linear step motor with an armature, a rod, arranged coaxially with the armature and being rigidly connected to it with the provision of a joint vertical displacement and a joint turning around a vertical axis and being made with the possibility of the formation of bayonet joint with a working element, forming a lock preventing a spontaneous turning of rod, characterized in that the bayonet joint is L-shaped, and the lock preventing a spontaneous turning of the rod comprises a guiding located inside the armature and being provided with a flange and a longitudinal through slot, a cross-piece rigidly connected to the armature and located in said slot for a vertical movement in it during a working stroke, a fixed immovable ring on which the inner surface of the flange rests, and a vertical pin, wherein in the outer rim of the flange there are regularly arranged through slots, and in the fixed immovable ring there are regularly and circumferentially arranged holes, in one of which the vertical pin is inserted and passes through one of through slots in the rim of the flange.

2. The actuating mechanism according to claim 1, characterized in that the through slots of the flange and the holes of the fixed ring are arranged relative to each other with a difference of angular pitches of not more than 2.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 Is an actuator mechanism of a nuclear reactor control and protection system (overall view, cross-section).

[0011] FIG. 2 shows the flange of the guided lock preventing spontaneous rotation of the rod (top view),

[0012] FIG. 3 shows an armature with a cross-piece (Section b-b).

BEST MODE OF CARRYING OUT THE INVENTION

[0013] The actuating mechanism of the control and protection system of a nuclear reactor comprises a linear step motor 1 with an armature (anchor) 2 in the form of a vertical tube, a rod 3 installed coaxially to the armature 2 and rigidly connected to it for a joint vertical displacement and turning about a common vertical axis, and a lock preventing spontaneous rotation of the rod 3. The lower end of the rod 3 is connected to the working member 4 by an L-shaped bayonet joint. The lock preventing a spontaneous rotation of the rod has a guiding section 5, a cross-piece 6, a fixed (immovable) ring 7 and a vertical pin 8. The guiding 5 is provided with a flange located at its upper end. The lower part of the guiding 5 is located inside the armature 2. The flange of the guiding rests with its inner surface on the fixed ring 7 and is centered with respect to its inner circumference. In the free lower part of guiding 5 there is a longitudinal through slot, in which a cross-piece 6 is installed, which is rigidly fixed to the armature 2 with the possibility of a vertical movement along the slot during a working stroke. Vertical through slots are formed in the outer rim of the flange of guiding 5, which are arranged uniformly over its circumference. The fixed ring 7 has vertical holes which are arranged uniformly over its circumference. A vertical pin 8 is mounted in one of vertical holes of the fixed ring 7, which passes through one of through slots of the flange of the guiding 5. The through slots of the flange of the guiding 5 and the holes of the fixed ring 7 are arranged relative to each other with a difference of angular pitches of not more than 2.

INDUSTRIAL APPLICABILITY

[0014] The actuating mechanism of the control and protection system of a nuclear reactor operates as follows.

[0015] The linear step motor 1 moves armature 2 and the rod 3 rigidly connected to the armature 2 and connected with working member 4 by an L-shaped bayonet joint in vertical direction. The vertical displacement of the working member 4 enhances or reduces the nuclear reaction in the nuclear reactor. To connect rod 3 to the working member 4, a vertical pin 8 is pulled out of the armature 2 until rod 3 rests against the angle of the bayonet joint within working member 4, whereafter rod 3 is turned together with armature 2 and the guiding 5 until rod 3 rests in the dead-end of the bayonet joint within working member 4, and then the vertical pin 8 is arranged in a through slot of the flange of guiding 5 and a hole in fixed ring 7. To disengage the rod 3 from the working member 4, the vertical pin 8 is pulled out of the hole in the fixed ring 7, then the rod 3 is turned together with armature 2 and the guiding 5 until the rod 3 rests against the angle (corner) of the bayonet connection within the working member 4, and then the rod 3 is lifted together with the armature 2 until the rod 3 leaves the bayonet connection within the working member 4, and then the vertical pin 8 is inserted through a slot of the flange of the guiding 5 into a hole in the fixed ring 7.