Fluid-Tight Torque Transmission via Bellows Seals
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Solution Overview
Problem
Existing valve actuation systems face challenges in achieving a gastight transmission to prevent leakage and explosion risks, especially under high pressures, and require sealing solutions that can handle environmental toxins and underwater applications.
Innovation Solution
A fluid-tight transmission system using radial rods or plungers encapsulated in bellows creates a static seal, eliminating the need for rotating seals and allowing for high-pressure operation by using a planetary gear-like construction with flexible bellows to absorb small movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rotating seals are used around the valve stem for actuation, then the valve can be actuated, but leakage and explosion risks occur due to sealing failures
Solution Approach 1:
The invention extracts the dynamic sealing function from the rotating seal and relocates it to a static seal. The bellows remains stationary while the push rod transmits motion through it, eliminating the need for rotating seals and their associated leakage risks.
Solution Approach 2:
The bellows acts as an intermediary element that transmits mechanical motion from the actuating body to the valve stem while maintaining a static seal. It mediates between the rotating eccentric mechanism and the linearly moving valve stem without requiring dynamic sealing.
2Stress or pressure
If traditional sealing solutions are used, then the valve can operate, but they fail under high pressure conditions
Solution Approach 1:
The bellows is constructed as a flexible metallic shell that can withstand high pressures while accommodating the necessary motion transmission. The corrugated structure of the bellows provides both flexibility for motion and strength for pressure resistance, maintaining sealing performance under high pressure conditions.
3Reliability
If radial rods are used for motion transmission, then a static seal can be achieved, but the structure becomes more complex
Solution Approach 1:
The bellows performs multiple functions simultaneously: it provides a static seal, transmits mechanical motion, accommodates the push rod movement, and resists high pressures. This multi-functionality reduces the need for additional separate components, thereby simplifying the overall structure despite the sophisticated sealing requirement.
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 effectively prevents leaks and explosion risks while maintaining high rigidity and low slip, enabling reliable operation in high-pressure environments, including underwater equipment, by utilizing a flexible bellows structure that can withstand pressures up to 100 bar or more.
Implementation Method 1
Each push rod (10) is encapsulated in a respective bellows (12)
Implementation Method 2
an internal cogwheel (1) with a number of teeth N-n, where n is a small number, usually 1, rotates within an external cogwheel (gear rim) (2) with a number of teeth N
Implementation Method 3
The rotation is produced by the internal cogwheel (1) being given an eccentric motion
Data Source
AI summary
Fluid-tight transmission comprising an internal cogwheel (19) with N-n teeth in cooperation with an external cogwheel (29) with N teeth. The internal cogwheel (1) is drivingly influenced by an eccentric (7; 17) via radially arranged push rods (10) encapsulated in respective bellows (12). The bellows are closely connected with a housing (3) comprising the external cogwheel (2). A fluid-tight barrier is thereby formed between a first rotatable element (8; 16), which drives the eccentric (7; 17), and a second rotatable element (14).