Powder Rotary Feedthrough Purge Chamber for High-Speed Sealing
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Solution Overview
Problem
Current rotary feedthroughs for non-lubricating powder-gas mixtures face issues with wear and leakage at high speeds, leading to uneven layer thickness and quality defects in thermal spraying applications, as powder particles settle and cause friction and pressure fluctuations, limiting operational speed and efficiency.
Innovation Solution
A rotary union with transverse flushing channels and resiliently prestressed flat sliding sealing surfaces, utilizing a flushing gas flow to remove powder particles and prevent wear, along with a non-stick coating to reduce friction and adhesion, allowing for continuous operation up to 2000 rpm with reduced leakage and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If flat sliding sealing surfaces are used in rotary feedthroughs for powder-gas mixtures, then sealing is achieved, but powder particles settle in the sealing gap causing friction, wear, and seizure at high speeds
Solution Approach 1:
The patent introduces a flushing gas system that blows powder particles out of the sealing gap between sliding sealing surfaces. Gas inlet channels deliver flushing gas to the sealing area, and gas outlet channels remove the gas-powder mixture, preventing particle accumulation that would cause wear and seizure at high rotational speeds
Solution Approach 2:
The flushing gas acts as an intermediary medium between the powder-gas mixture and the sealing surfaces. It mediates by carrying away powder particles that would otherwise settle in the sealing gap, enabling continuous high-speed operation without particle-induced wear
2Productivity
If rotational speed is increased to improve productivity, then coating efficiency increases, but wear and leakage at the rotary feedthrough increase leading to quality defects
Solution Approach 1:
The flushing gas system maintains sealing integrity at high rotational speeds by continuously removing powder particles from the sealing gap, preventing wear that would cause leakage and powder flow pulsations, thereby ensuring uniform layer thickness in coating applications
3Reliability
If cylindrical sealing gaps are used to reduce leakage, then sealing performance improves, but powder particles settle in the gap causing rapid seizure
Solution Approach 1:
The patent employs flushing gas channels that blow powder particles out of the sealing gap between cylindrical sealing surfaces. This pneumatic cleaning prevents particle accumulation and seizure, extending the service life of the rotary feedthrough while maintaining effective sealing performance
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 enables low wear and efficient powder-gas mixture transfer at high speeds, minimizing leakage and ensuring consistent layer quality by effectively removing powder particles and maintaining sealing integrity, thus reducing operational costs and improving coating quality.
Implementation Method 1
a flushing channel running transversely to the axis of the sliding sealing disks... allows a flushing agent to flow transversely to the axis of the sliding sealing disks and past them on the outside... frees these sliding disks from powder particles
Implementation Method 2
resiliently prestressed flat sliding sealing surfaces
Implementation Method 3
non-stick coating to reduce friction and adhesion
Data Source
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AI summary
The invention relates to a rotary feedthrough (201) for the feeding through of a powder-gas mixture from a stationary machine part into a rotating machine part, comprising a seal in the form of two flat, circular-ring-shaped sliding sealing surfaces (207f, 207r) arranged one on the other in a sliding manner, which sliding sealing surfaces are arranged concentric to the axis of rotation of the rotating machine part and can be moved apart from each other in the axial direction such that the sliding sealing surfaces form a gap, wherein the seal is embedded in a purge chamber (209) having at least one gas inlet (211) and at least one gas outlet (213).