Passage selector of reactor in-core nuclear-measuring apparatus
An object of the invention is to embody a small and inexpensive passage selector, which can be applied by commonly using an index device even if the number of detector passages is changed, and which is easy to make inspection and maintenance. The passage selector of a reactor in-core nuclear-measuring apparatus of the invention includes: a drive motor; an index device that is driven by the drive motor and that makes a rotary output of a predetermined index number; a central rotating shaft that is driven to rotate by the index device and that causes a passage selecting guide tube to be located in opposition to any detector passage; and a speed-increasing and decreasing device that is interposed between an output shaft of the index device and the central rotating shaft, and that adjusts the index number of the central rotating shaft.
1. A passage selector of a reactor in-core nuclear-measuring apparatus, comprising:
a passage selecting guide tube;
a plurality of detector passages;
a drive motor;
an index device that is driven by said drive motor, the index device including an output shaft that makes a rotary output of a fixed predetermined index number;
a central rotating shaft that is rotated so as to cause the passage selecting guide tube to be aligned to a detector passage; and
a speed-increasing and decreasing device that comprises a first gear directly connected to the output shaft of the index device and a second gear that is meshed with said first gear and directly connected to said central rotating shaft; and
wherein when a stop number (index number) of the index device is Y where a teeth number of the first gear is Z1, and a teeth number of the second gear is Z2, the stop number (index number) of the central rotating shaft is Y×Z2/Z1.
2. A passage selector of a reactor in-core nuclear-measuring apparatus, comprising:
a passage selecting guide tube;
a plurality of detector passages;
a drive motor;
an index device that is driven by said drive motor, the index device including an output shaft that makes a rotary output of a fixed predetermined index number;
a central rotating shaft that is rotated so as to cause the passage selecting guide tube to be aligned to a detector passage; and
a speed-increasing and decreasing device that comprises a first gear directly connected to the output shaft of the index device and a second gear that is meshed with said first gear and directly connected to said central rotating shaft; and
wherein when an input shaft of the index device makes one revolution by the drive motor, an output shaft of the index device makes 1/Y revolution in accordance with an index number Y that is specific to the index device, where a teeth number of the first gear is Z1, and a teeth number of the second gear is Z2, the revolutions of the central rotating shaft is set to be 1/Y×Z1/Z2.