Two-Material Valve Seal With Hard Bead for Thermal Tightness
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Solution Overview
Problem
Existing fluid valve seals fail to maintain long-term tightness under large temperature fluctuations in combustion engine or electric motor peripheries and are not cost-effective.
Innovation Solution
A seal comprising a first elastically deformable plastic part and a second hard plastic part, with the latter being vulcanized as a thin layer onto the former, forming a one-piece arrangement with a circumferentially projecting bead for static and dynamic sealing, and optionally incorporating a metal or plastic support element for enhanced stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-material seal is used, then the seal structure is simple and production cost is low, but the seal cannot maintain tightness under large temperature fluctuations and varying pressures
Solution Approach 1:
The seal combines two different plastic materials with complementary properties: a hard plastic (e.g., PTFE) for the sealing bead that provides low friction and good sealing against the valve body, and a soft plastic for the body that provides elastic deformability to accommodate temperature variations and pressure changes. This composite structure resolves the contradiction by integrating material diversity to achieve reliable tightness while maintaining a relatively simple overall seal design.
2Ease of operation
If a hard sealing element is used, then the seal provides good lubricity and sealing against the valve body, but the seal lacks elastic deformability to accommodate tolerance positions
Solution Approach 1:
The seal applies local quality by using different materials in different regions: the hard plastic is concentrated in the sealing bead area where contact with the valve body occurs, providing low friction and good sealing. The soft plastic forms the main body where elastic deformability is needed to accommodate tolerance positions and pressure variations. This spatial differentiation of material properties resolves the contradiction between hard sealing and elastic adaptability.
3Ease of manufacture
If a thin-walled structure is used for the second plastic part, then material cost is reduced, but the structural strength may be compromised
Solution Approach 1:
The second plastic part is designed as a thin-walled structure that leverages the elastic properties of the soft plastic material to provide sufficient strength and flexibility. The thin-walled design reduces material consumption and production costs while the elastic material compensates for the reduced thickness, maintaining adequate structural strength to withstand operating pressures and temperature fluctuations without compromising the seal's functionality.
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 seal provides optimal interaction with valve bodies and housings, maintaining tightness under varying pressures and temperatures while reducing material and production costs.
Implementation Method 1
The first plastic part gives the seal a desired elastic deformability or a desired elastic behavior
Implementation Method 2
The hard sealing element gives the seal the desired hardness and lubricity in order to be able to interact optimally with the valve body
Implementation Method 3
the second plastic part, designed as a hard sealing element, which is connected to the first plastic part
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A seal 4 for use in a fluid valve 2 is proposed. The seal 4 comprises a first elastically deformable plastic part 10 and a second plastic part 12, designed as a rigid sealing element, which is connected to the first plastic part 10. The first and second plastic parts 10 and 12 together form a sealing arrangement 4 with a first end face SEI for sealing against an adjustable valve body 6 of the fluid valve 2 and a second end face SEII for sealing against a valve housing 8 of the fluid valve 2. At least the first end face SEI has a first end face SI with a circumferentially projecting bead 15 for sealing against the adjustable valve body 6. A fluid valve 2 with at least one such seal 4 is also proposed.