Two-Part Bayonet Disk for Control Rod Guide Tube
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing bayonet lock mechanism for control rod guide tubes in boiling water reactors faces challenges with mountability and ease of removal due to deposits causing sluggishness and the deep location of base plates, making dismantling difficult and time-consuming.
Innovation Solution
A two-part bayonet disk design with a central bayonet ring and an outer ring under spring pressure, allowing for easy unlocking and locking by pressing down the outer ring with a tool, ensuring a defined force bracing and rotationally locked connection, and incorporating a disc spring for radial sliding fit to facilitate assembly and disassembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional bayonet lock mechanism is used to securely brace the control rod guide tube, then reliability of the connection is improved, but ease of operation deteriorates due to deposits causing sluggishness and deep location making dismantling difficult
Solution Approach 1:
The bayonet disk is divided into two separate rings: an inner bayonet ring that provides rotational locking and an outer ring that applies axial spring pressure. This segmentation allows the outer ring to be independently pressed down with a tool to release the locking force, enabling easy dismantling even when deposits are present, while the inner bayonet ring maintains reliable rotational bracing when locked
Solution Approach 2:
A disc spring is introduced as an intermediary element between the outer ring and the control rod guide tube base plate. The spring continuously applies axial pressing force to ensure firm bracing and rotational locking, but this force can be easily released by pressing the outer ring down with a tool, allowing straightforward dismantling without requiring excessive force that would be hindered by deposits
2Stability of the object's composition
If firm bracing is applied to prevent lifting and bypass of the control rod guide tube, then connection stability is improved, but device complexity increases due to the two-part bayonet disk design
Solution Approach 1:
The two separate rings (inner bayonet ring and outer ring) are designed to work together as an integrated locking system. The outer ring engages with the inner bayonet ring, combining axial spring pressure with rotational locking in a single compact assembly that provides enhanced stability without requiring separate complex mechanisms for each function
3Reliability
If the base plate is located at great depth for proper control rod guidance, then functional performance is improved, but ease of operation deteriorates due to difficult access for maintenance
Solution Approach 1:
The outer ring is designed to be independently actuated and removable from the inner bayonet ring. This allows the outer ring, which applies the spring pressure, to be extracted or manipulated separately using a tool pressed down from above, enabling maintenance operations at the deeply located base plate without requiring removal of the entire control rod guide tube assembly
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides reliable bracing and vibration-free installation of the control rod guide tube, simplifies assembly by allowing the outer ring to be pressed down for unlocking, and ensures secure locking with defined force, preventing unwanted movements and ensuring easy access for maintenance.
Implementation Method 1
The spring element, which is provided for generating the spring pressure and is preferably designed as a disc spring, surrounds the drive housing tube with a radial sliding fit
Data Source
Figure 1
Figure 2~3
AI summary
The bayonet plate of the bayonet plate closure between control rod guide tube (1) and drive housing pipe (2) of a boiling water reactor is designed in two parts. It comprises a central bayonet ring (6) mounted rotatably about its longitudinal axis (3) with an outer ring (7) completely surrounding said bayonet ring. The outer ring (7) is mounted on the circumference of the bayonet ring (6) and reaches inwards under the bayonet ring circumference. Said ring is furthermore permanently supported in the axial direction on the drive housing pipe (2) by the spring pressure acting on the control rod guide tube (1), in order to produce a frictional connection. This spring pressure can be released unhindered from the reactor side by tools.