Rotary Damper Sealing Ring Structure for Misalignment Control
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Solution Overview
Problem
Existing dampers using O-rings to prevent viscous fluid leakage face misalignment issues due to external forces, leading to instability in the seal and potential leakage, as enhancing O-ring stiffness to prevent misalignment can cause gaps and further leakage.
Innovation Solution
A damper design featuring a bushing to hold the resistance generating member slidably, with an annular elastic member having specific width dimensions on its inner and outer surfaces to maintain seal tightness without requiring high stiffness, reducing misalignment and leakage risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the stiffness of the O-ring is enhanced to prevent misalignment, then the misalignment is reduced, but the O-ring resists elastic deformation and generates gaps causing viscous fluid leakage
Solution Approach 1:
The invention changes the geometric parameters of the elastic member from a circular cross-section (O-ring) to a rectangular cross-section. This parameter change allows the member to maintain contact with both the resistance generating member and the fluid holding chamber while deforming elastically, preventing both misalignment and leakage without requiring high stiffness
Solution Approach 2:
The invention uses a flexible elastic member with rectangular cross-section that can deform elastically under external forces. This flexible member maintains sealing contact through its ability to deform rather than through high stiffness, resolving the contradiction between alignment precision and sealing reliability
2Manufacturing precision
If the O-ring is made more compliant to allow elastic deformation, then misalignment is reduced, but the seal stability deteriorates causing leakage
Solution Approach 1:
The rectangular cross-section elastic member provides flexibility for alignment correction while maintaining seal stability through its geometric shape. The flat surfaces of the rectangular section ensure stable contact areas with both the resistance generating member and the fluid holding chamber, preventing leakage even when deformed
Solution Approach 2:
The invention uses an elastic member made of elastomeric material with specific properties (JIS A 30-50 hardness) that combines flexibility for alignment adjustment with sufficient structural integrity to maintain stable sealing contact, resolving the contradiction between compliance and stability
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 design effectively reduces misalignment and leakage by allowing the elastic member to deform elastically, maintaining seal tightness and preventing external leakage of viscous fluid, even without increased stiffness, thus enhancing the damper's sealing performance.
Implementation Method 1
an elastic member in an annular shape located between the resistance generating member held by the bushing and the opening section of the fluid holding chamber
Implementation Method 2
a damper that limits the movement of viscous fluid to apply a damping force in reaction to an external force
Data Source
Figure 1(A)~1(C)
Figure 2(A)~2(B)
Figure 3(A)~3(B)
AI summary
A rotary damper (1) has a first sealing ring (8a) and a first bushing (4a) which are located between a through-hole (23) of a circular cylindrical chamber (21) inside a case (2) and a lower end part (33a) of a rotor body (31) of a rotor (3), and a second sealing ring (8b) and a second bushing (4b) which are located between a through-hole (60) in a lid (6) and an upper end part (33b) of the rotor body (31). The first sealing ring (8a) has an outer peripheral surface (85) having a width in a direction of a center axis of the circular cylindrical chamber (21) and being pressed against an inner peripheral surface (220) of the through-hole (23), and an inner peripheral surface (84) having a width in the direction of the center axis of the circular cylindrical chamber (21) and being pressed against an outer peripheral surface (34) of the lower end part (33a), and the second sealing ring (8b) has an outer peripheral surface (85) having a width in the direction of the center axis of the circular cylindrical chamber (21) and being pressed against an inner peripheral surface (64) of the through-hole 961 (60), and an inner peripheral surface (84) having a width in the direction of the center axis of the circular cylindrical chamber (21) and being pressed against the outer peripheral surface (34) of the upper end part (33b).