Rotary-Linear Shaft Sealing with Axial Seal Switching
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Solution Overview
Problem
Conventional sealing apparatuses for vacuum pressure equipment fail to simultaneously enable both linear and rotational motion without damaging the sealing members, leading to frequent replacements and potential fluid leakage.
Innovation Solution
A sealing apparatus design featuring a housing, a hollow first shaft, and a second shaft with multiple sealing members that allow for linear and rotational motion by using a third sealing member that switches sealing positions based on the second shaft's axial movement, preventing fluid leakage and enabling easy replacement of damaged sealing members.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single sealing member is used to seal both linear and rotational motion simultaneously, then the sealing function is simplified, but the seal is easily damaged and has a short life
Solution Approach 1:
The sealing function is divided into two separate sealing members: a first sealing member for sealing linear motion between the housing and first shaft, and a second sealing member for sealing rotational motion between the first shaft and second shaft. This segmentation allows each seal to be optimized for its specific motion type, preventing damage and extending service life.
Solution Approach 2:
The invention introduces an axial dimension for replacement by providing multiple second sealing members positioned at different axial locations. When one seal wears out, the second shaft can be moved axially to engage the next sealing member, adding a temporal dimension to the sealing system's functionality.
2Device complexity
If the second shaft is fixed in position, then the sealing structure is simple, but the sealing member cannot be replaced when damaged
Solution Approach 1:
The second shaft is designed to be movable in the axial direction rather than fixed, allowing it to be repositioned to engage different second sealing members. This dynamic capability enables easy replacement of worn seals without disassembling the entire apparatus, while the groove structure provides stable positioning when engaged.
3Reliability
If the third sealing member is positioned to always seal, then sealing is continuous, but the sealing member cannot be used for replacement when damaged
Solution Approach 1:
Multiple second sealing members are provided in excess at different axial positions, but only one is engaged at a time. This allows the system to have continuous sealing capability while enabling replacement of individual seals by moving the second shaft to engage a different sealing member from the available set.
Data Source
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AI summary
Provided is a sealing apparatus capable of linear and rotational motion including a housing; a hollow first shaft penetrating and coupled to the housing; a first sealing member provided between the housing and the first shaft to seal therebetween; a second shaft of which at least a part is inserted into the first shaft; a second sealing member provided between the first shaft and the second shaft to seal therebetween; and a third sealing member provided on either an inner circumferential surface of the first shaft or an outer circumferential surface of the second shaft.