Dual-Bellows Vacuum Capacitor for High-Speed Capacitance Control
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Solution Overview
Problem
Existing vacuum capacitors face challenges in performing high-speed control and fine adjustment of capacitance due to large and fluctuating operating forces, making it difficult to support high-speed operations in high-frequency apparatus.
Innovation Solution
A vacuum capacitor design incorporating a main bellows and an adjustment bellows with equal vacuum pressure and spring constant, connected via an insulating connection rod, allows for reduced operating forces by canceling out retraction forces and enabling high-speed capacitance control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a main bellows is used to maintain vacuum seal during electrode movement, then vacuum tightness is ensured, but the retraction force becomes large and fluctuating, making high-speed control difficult
Solution Approach 1:
The patent introduces a counter-bellows structure that generates a retraction force in the opposite direction to the main bellows' retraction force. By positioning the counter-bellows to expand and contract in opposition to the main bellows, the system creates a counterbalancing effect that reduces the net retraction force acting on the movable electrode, thereby easing the operating force requirement while maintaining vacuum seal integrity.
Solution Approach 2:
The patent employs asymmetric bellows configuration where the counter-bellows is positioned and dimensioned to create an opposing force that is not equal to but complements the main bellows force. This asymmetric arrangement allows the two bellows structures to work together in a push-pull manner, with each bellows operating at different phases of expansion and contraction to achieve force cancellation while maintaining the vacuum seal.
2Adaptability or versatility
If the movable electrode is inserted and removed to adjust capacitance, then capacitance control is achieved, but the large and fluctuating operating force makes fine adjustment and high-speed control difficult
Solution Approach 1:
The counter-bellows structure provides a balancing force that compensates for the main bellows' fluctuating retraction force during electrode movement. This force cancellation effect reduces the net force that the driving mechanism must overcome, enabling smoother and faster movement of the movable electrode for capacitance adjustment, thereby improving operation speed and control precision.
Solution Approach 2:
The patent changes the physical state and operational parameters of the bellows system by introducing a second bellows with opposite phase expansion and contraction. This parameter change transforms the single-direction retraction force into a balanced, reduced-force system, allowing the movable electrode to be positioned more rapidly and precisely for capacitance control.
3Device complexity
If a single bellows structure is used, then the structure is simple, but the retraction force is large and fluctuating, causing difficulty in high-speed operation
Solution Approach 1:
The patent merges two bellows structures (main bellows and counter-bellows) into a single integrated vacuum capacitor system. Although this increases structural complexity, the combined operation of the two bellows in opposite phases produces a net reduction in retraction force, enabling high-speed operation. The merging of these complementary structures achieves both force reduction and maintained vacuum seal.
Solution Approach 2:
The patent introduces dynamic operation to the bellows system where the counter-bellows expands and contracts in opposition to the main bellows during electrode movement. This dynamic, out-of-phase operation allows the system to actively compensate for retraction forces in real-time, reducing the net force fluctuation and enabling faster, more precise capacitance adjustment compared to a static single-bellows design.
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 design achieves stable and easily adjustable capacitance control with reduced operating forces, facilitating high-speed operations and simplified maintenance.
Implementation Method 1
the adjustment bellows has a vacuum pressure equal to or less than that of the main bellows
Implementation Method 2
the main bellows and the adjustment bellows have a same spring constant and an expansion and contraction rate
Implementation Method 3
The main bellows 14 has a bellows shape and is made of a thin and flexible metal
Data Source
AI summary
A vacuum capacitor is provided with a vacuum container accommodating a fixed electrode and movable electrode to ensure capacitance, and a vacuum expansion container communicating with the vacuum container in series. The vacuum container is provided with a movable support part supporting the movable electrode, a movable conductor supporting the movable support part to enable reciprocation in the axial direction of the vacuum container, a fixed conductor supporting the fixed electrode, and a main bellows interposed between the movable support part and the movable conductor. The vacuum expansion container is provided with a movable part arranged coaxially with the movable support part, and an adjustment bellows interposed between the movable part and the inner end surface of the vacuum expansion container. The movable support part and movable part are connected by an insulating connection rod arranged coaxially with the fixed electrode and movable electrode.