Integrated Shaft Seal Structure for Rotary Eccentricity Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sealing devices in exhaust gas recirculation systems face unstable sealing performance due to rotary shaft eccentricity, which is not effectively addressed without increasing installation space or costs by adding separate bearings.
Innovation Solution
A sealing device configuration that includes a metal ring, a plate-shaped resin seal, a flat spring, and a metal or resin slide bearing, which limits rotary shaft eccentricity while maintaining stable sealing performance over time by curving the resin seal and pressing it radially inward, and sliding on the rotary shaft to counteract eccentric motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate bearing is provided to limit rotary shaft eccentricity, then the sealing performance stability is improved, but the device complexity and installation space increase
Solution Approach 1:
The patent combines the bearing function with the sealing device by integrating a slide bearing into the sealing structure. The slide bearing is positioned between the resin seal and the inward flange section, allowing the sealing device to simultaneously perform sealing and eccentricity limitation functions without requiring a separate bearing component.
Solution Approach 2:
The sealing device is designed to perform multiple functions: sealing the annular gap between the rotary shaft and housing, and limiting rotary shaft eccentricity. The slide bearing component enables the sealing device to support radial loads and constrain eccentric motion, making the device universal in handling both sealing and bearing requirements.
2Reliability
If a separate bearing is provided to limit rotary shaft eccentricity, then the sealing performance stability is improved, but the installation space increases
Solution Approach 1:
The bearing function is merged into the sealing device structure. The slide bearing is integrated between the resin seal and inward flange section, eliminating the need for additional bearing installation space while maintaining the ability to limit rotary shaft eccentricity.
Solution Approach 2:
The slide bearing is nested within the sealing device structure, positioned between the resin seal and inward flange section. This nested arrangement allows the bearing function to be accommodated within the existing sealing device footprint without requiring additional installation space.
3Temperature
If a resin seal is used in high-temperature environment, then the heat resistance is improved, but the sealing performance degrades over time due to creep relaxation
Solution Approach 1:
The sealing device uses a composite structure combining resin seal material with metal components (flat spring and slide bearing). The resin seal provides heat resistance while the metal components provide structural support and maintain sealing pressure, compensating for the resin's creep relaxation in high-temperature environments.
Solution Approach 2:
Different parts of the sealing device have different material properties optimized for their specific functions. The resin seal material provides heat resistance where needed, while metal components provide mechanical strength and elasticity in other areas to maintain sealing performance over time under thermal stress.
4Productivity
If the rotary shaft rotates at high speed with eccentricity, then the productivity is improved, but the sealing performance becomes unstable due to dynamic eccentricity
Solution Approach 1:
The slide bearing acts as an intermediary between the rotary shaft and sealing components. It mediates the dynamic eccentricity by providing a sliding contact surface that accommodates radial movements while maintaining stable sealing contact, allowing high-speed rotation without compromising 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 effectively limits rotary shaft eccentricity without additional bearings, ensuring stable sealing performance and resisting heat and sliding wear, thus preventing performance degradation from creep relaxation and dynamic eccentricity.
Implementation Method 1
a flat spring including a plate-shaped annular metal member, an outer circumference side of the flat spring being fixed to the metal ring and an inner circumference side of the flat spring being configured to deform to curve along the resin seal and press the inner circumference side of the resin seal radially inward
Implementation Method 2
an inner circumference side of the resin seal being configured to be in close contact with and slide on an outer circumference surface of the rotary shaft
Data Source
AI summary
A sealing device includes a metal ring 110 with a cylindrical section 111 and an inward flange section 112 disposed at one end of the cylindrical section 111. A resin seal 120 has an outer circumference side fixed to the metal ring 110 and an inner circumference side configured to slidably and closely come into contact with an outer circumference surface of the rotary shaft in a state deformed to curve toward a sealing target region. A flat spring 130 includes a plate-shaped annular metal member and has an outer circumference side fixed to the metal ring 110 and an inner circumference side configured to deform to curve along the resin seal 120 and press the inner circumference side of the resin seal 120 radially inward. A metal slide bearing 140, is sandwiched between the resin seal 120 and the inward flange section 112 and configured to slide on the outer circumference surface of the rotary shaft.