Fuel Cell Gas Flap Bearing Seal for Leak-Tight Shaft Coupling
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Solution Overview
Problem
Fuel cell systems require control flap assemblies that can effectively prevent gas leaks while maintaining a structurally simple design, as existing solutions often fail to ensure tightness and prevent gas escape to the environment.
Innovation Solution
A control flap assembly featuring a disk-like valve body on a pivot shaft with a sealing element that rests on the outer peripheral surface, supported by a bearing unit with a bearing ring, providing a gas-tight seal through a combination of axial and radial sealing sections, and a press-fit bearing bush for stable mounting, ensuring no gas leakage even with bearing play.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a control flap assembly is designed with a pivot shaft that passes through the bearing area to enable coupling with the drive, then the coupling function is achieved, but gas leakage occurs through the bearing play
Solution Approach 1:
A sealing element is introduced as an intermediary component between the pivot shaft and the bearing unit. This sealing element rests against the outer peripheral surface of the pivot shaft and is carried in the bearing unit, effectively blocking the gas leakage path created by the pivot shaft passing through the bearing area while allowing the pivot shaft to rotate freely for coupling operation.
2Reliability
If the pivot shaft is completely enclosed in the bearing area to prevent gas leakage, then gas tightness is improved, but the coupling with the drive becomes difficult
Solution Approach 1:
The bearing area is designed with differentiated local qualities: the bearing unit provides gas-tight enclosure for the pivot shaft, while the sealing element creates a localized sealing zone at the interface between the pivot shaft and bearing unit. This allows the pivot shaft to pass through the bearing area for coupling while maintaining gas tightness through the localized sealing action.
3Reliability
If a sealing element is added to the bearing unit to prevent gas leakage, then gas tightness is improved, but the device complexity increases
Solution Approach 1:
The sealing element is merged with the bearing unit structure, where the bearing unit carries and positions the sealing element. This integration allows the sealing function to be added to the bearing unit without requiring a completely separate sealing mechanism, thereby improving gas tightness while minimizing the increase in device complexity.
Data Source
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AI summary
A control valve assembly, in particular for a gas flow in a fuel cell system, especially in a vehicle, comprises a control valve housing (14) providing a gas flow channel, a control valve adjustable in the control valve housing (14) between a closed position which substantially prevents gas flow through the gas flow channel and at least one open position which releases the gas flow channel for flow, with a disk-shaped control valve body supported on a pivot shaft (18) rotatable about a pivot shaft axis (A), wherein the pivot shaft (18) has a first pivot shaft end section (48) mounted on the control valve housing (14) and rotatable about the pivot shaft axis (A) in a first bearing area (28), and a second pivot shaft end section rotatably mounted on the control valve housing (14) about the pivot shaft axis (A) in a second bearing area.wherein at least one bearing area of first bearing area (28) and second bearing area comprises a bearing unit (62) rotatably supporting the pivot shaft (18) and at least one sealing element (70) carried in the bearing unit (62) and bearing against an outer circumferential surface of the pivot shaft (18).