Integral PTFE Guide Bushing for Sealing and Guiding
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Solution Overview
Problem
Existing devices for guiding and sealing linear sliding movements of force transmission elements between areas with different media face challenges such as high manufacturing costs and durability issues due to material limitations, especially under fluctuating temperature and pressure conditions.
Innovation Solution
A one-piece guide bush with integral polymer body featuring drainage openings and made from PTFE or PVDF, which provides both guiding and sealing functions with low friction resistance, dimensional stability, and resistance to embrittlement, along with expandable sheet metal parts for enhanced sealing and fixation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If composite bodies with multiple sealing elements and guide bodies are assembled to achieve sealing function, then sealing effectiveness is improved, but manufacturing cost and assembly complexity increase
Solution Approach 1:
The patent combines the guide body and sealing elements into a single integrated component made of PTFE or PVDF. The guide bushing incorporates both guiding surfaces and sealing lips in one piece, eliminating the need to assemble separate guide bodies and sealing elements, thus reducing assembly complexity while maintaining sealing effectiveness
Solution Approach 2:
The guide bushing performs multiple functions simultaneously: it guides the linear sliding movement of the force transmission element and provides sealing between different media areas. The integral design combines guiding and sealing functions in a single component, reducing the number of parts needed
2Reliability
If traditional sealing materials like NBR or HNBR are used to achieve sealing, then sealing effectiveness is improved, but durability deteriorates due to embrittlement from fluid contact and temperature fluctuations
Solution Approach 1:
The patent changes the material parameters by using PTFE or PVDF instead of traditional rubber materials like NBR or HNBR. These fluoropolymers exhibit superior resistance to embrittlement from fluid contact and temperature fluctuations, maintaining sealing effectiveness throughout the service life without deteriorating
Solution Approach 2:
The patent employs fluoropolymer materials (PTFE or PVDF) that combine both guiding and sealing functions in a single material system. These materials provide the necessary mechanical properties for guiding while simultaneously offering excellent chemical resistance and durability in contact with fluids and temperature variations
3Reliability
If multiple individual parts are produced and assembled to achieve sealing, then sealing effectiveness is improved, but manufacturing cost increases due to high production effort
Solution Approach 1:
The patent merges the production of guide bodies and sealing elements into a single manufacturing process. The integral guide bushing is produced as one piece through injection molding or similar processes, eliminating the need for separate production and assembly steps, thus reducing manufacturing cost while maintaining sealing effectiveness
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 offers a cost-effective, durable, and simplified assembly method for guiding and sealing power transmission elements, ensuring both static and dynamic sealing efficacy even under dynamic loading conditions, preventing malfunctions due to dimensional changes.
Implementation Method 1
at least one drainage opening is arranged in a guide section, which establishes a liquid connection between an inner guide surface and an outer surface of the guide section
Implementation Method 2
both pure PTFE or a modified PTFE compound consisting of an injection-moldable polymer compound of PTFE and another plastic, as well as PVDF (polyvinylidene fluoridate), are advantageously suited in the present application to realize a guiding function of the sliding movement with low frictional resistance
Implementation Method 3
PTFE or PVDF, under the design of the integral sealing sections, also exhibit good sealing properties between a gaseous and a liquid medium under dynamic load. In the present application, the use of PTFE or PVDF as a sealing material has the advantage that PTFE or PVDF also prove to be dimensionally stable under the operating fluids and fluctuating operating conditions
Data Source
Figure 1~2
AI summary
A device for guiding a linear sliding motion of a force transmission element (3) in a passage opening (4) between two areas (41, 42) containing different media comprises a guide bushing (1). The guide bushing (1) has sealing sections (11) extending to the axial ends of the guide section (10) and branching into at least one radially inner lip section (12a) and one radially outer lip section (12b). Spreading elements (2), which can generate a spreading effect between two radii by means of elastic preload, are arranged in a radial branch of the sealing sections (11) between the inner lip section (12a) and the outer lip section (12b). The guide section (10) and the sealing sections (11) are together formed as an integral body made of PTFE, a PTFE-containing polymer compound, or PVDF.