Cryogenic Valve Actuation With Membrane Strain Wave Sealing
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Solution Overview
Problem
Existing valve actuation mechanisms for cryogenic and H2 applications face challenges in achieving high anti-leakage requirements, particularly with rotational seals for ball valves, which are difficult to design as gas-tight for liquid hydrogen use, leading to potential leakage issues.
Innovation Solution
A valve actuation mechanism utilizing a strain wave gearing system with a flexible ring gear as part of the sealing membrane, which transmits rotational movement through elastic deformation, eliminating relative movement and minimizing leakage by integrating the sealing function within the strain wave gearing mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rotational seal is used for ball valve actuation in cryogenic H2 applications, then the valve can be actuated, but leakage occurs due to difficulty in achieving gas-tight sealing
Solution Approach 1:
The patent extracts the sealing function from the rotational movement interface by introducing a membrane seal that separates the inner and outer areas. The membrane acts as a barrier that prevents hydrogen leakage while allowing rotational actuation to occur on either side of the seal, effectively removing the leakage problem from the actuation mechanism.
Solution Approach 2:
The patent employs a flexible membrane seal that can deform to accommodate rotational movement while maintaining sealing integrity. This thin film structure allows the actuation mechanism to rotate without compromising the gas-tight seal, solving the contradiction between rotational capability and leakage prevention.
2Reliability
If a strain wave gearing system is implemented, then rotational movement transmission is achieved without dynamic seals, but the device complexity increases
Solution Approach 1:
The patent merges the sealing function with the gearing mechanism by integrating the membrane seal into the strain wave gearing system. The membrane serves dual purposes: sealing the hydrogen-containing area and transmitting the actuation force through the strain wave gearing, thereby combining multiple functions into a single integrated component.
Solution Approach 2:
The membrane seal in the strain wave gearing system performs multiple functions simultaneously: it acts as a gas-tight barrier, transmits rotational actuation force, and enables the strain wave gearing mechanism to operate without dynamic seals. This multi-functionality reduces the need for separate components.
3Device complexity
If the flexible ring gear is integrated into the sealing membrane, then the number of components is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent combines the flexible ring gear with the sealing membrane into a single integrated component. This merging eliminates the need for separate ring gear and seal components, reducing assembly steps and potential leakage points while maintaining the functional integrity of both sealing and gearing mechanisms.
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 achieves extremely low leakage rates by securely sealing the inner area from the outer area, maintaining vacuum integrity and allowing efficient rotational movement transmission without dynamic seals, thus ensuring high safety against hydrogen leakage.
Implementation Method 1
a strain wave gearing connecting the input shaft and the output shaft, wherein the strain wave gearing comprises a wave generator connected to one of the input and output shafts, a rotatable outer gear wheel connected to the other of the input and output shafts and a stationary flexible ring gear with external teeth which is deformed by the wave generator to engage with internal gear teeth of the outer gear wheel
Implementation Method 2
a housing defining an inner area which is sealed by a sealing membrane from an outer area
Data Source
Figure 1~2
Figure 3
Figure 4~6
AI summary
In order to improve a valve actuating mechanism (10) for use with high anti-leakage requirements, the invention provides a valve actuation mechanism (10) for actuating a rotatable closing element (16) of a valve (12) for cryogenic applications and/or H2 applications, comprising: a housing (22) defining an inner area (32) which is sealed by a sealing membrane (24) from an outer area (34), an input shaft (26) for receiving a rotational movement wherein the input shaft (26) is arranged in the outer area (34), an output shaft (28) to be connected to the closing element (16), wherein the output shaft (28) is arranged in the inner area (32), and a strain wave gearing (30) connecting the input shaft (26) and the output shaft (28), wherein the strain wave gearing (30) comprises a wave generator (38) connected to one of the input and output shafts (26, 28), a rotatable outer gear wheel (40) connected to the other one of the input and output shafts (26, 28) and a stationary flexible ring gear (42) with external teeth (44) which is deformed by the wave generator (38) to engage with internal gear teeth (46) of the outer gear wheel (40), wherein the flexible ring gear (42) is provided as a portion (48) of the sealing membrane (24).