Rotation Damper Seal Hardness Optimization for Torque Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing dampers face challenges in reducing starting torque and torque variability, particularly in low-speed rotational areas, due to limitations in seal material properties.
Innovation Solution
A damper design utilizing an annular seal material made of silicone rubber with a hardness of 25 to 45 degrees Durometer Hardness Testing and a loss tangent of 0.12 to 0.25 at 23°C ± 2°C, preventing oil leakage and stabilizing torque waveforms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the hardness of the annular seal material is increased to improve molding feasibility, then the ease of manufacture is improved, but the starting torque and torque variability increase
Solution Approach 1:
The patent applies parameter changes by precisely controlling the hardness of the annular seal material within the range of 25 to 45 degrees on the Durometer scale. This parameter optimization resolves the contradiction by finding the optimal hardness value that is sufficiently hard to be moldable yet soft enough to minimize starting torque and torque variability, thereby satisfying both manufacturing feasibility and performance requirements.
2Stability of the object's composition
If the hardness of the annular seal material is increased to reduce torque variability, then the stability of torque is improved, but the starting torque increases
Solution Approach 1:
The patent resolves this contradiction through parameter changes by optimizing the hardness of the annular seal material to within 25-45 degrees Durometer. This controlled parameter range achieves the dual benefit of stabilizing torque characteristics while keeping starting torque at acceptable levels, demonstrating that extreme hardness values are not necessary for torque stability.
3Reliability
If a harder seal material is used to prevent oil leakage, then the reliability is improved, but the torque waveform stability deteriorates
Solution Approach 1:
The patent applies parameter changes by setting the annular seal material hardness to 25-45 degrees on the Durometer scale. This optimized parameter range ensures adequate sealing performance to prevent oil leakage while simultaneously maintaining smooth torque waveforms without excessive peaks and valleys, resolving the contradiction between reliability and torque waveform 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 solution effectively reduces starting torque and torque variability in low-speed areas, preventing stick-slip and stabilizing torque waveforms, while ensuring feasible molding of the seal material.
Implementation Method 1
an annular seal material provided to be disposed between the housing and the rotating shaft in order to prevent the damper oil from leaking
Implementation Method 2
The annular seal material is formed by silicone rubber having a hardness of 25 degrees or above and 45 degrees or less
Implementation Method 3
the loss tangent is 0.12 or above and 0.25 or less at the temperature of 23°C ± 2°C obtained from the dynamic viscoelastic measurement in the frequency of 1Hz. Consequently, stick-slip caused by the annular seal material is difficult to occur
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
A silicone oil (18) is filled inside a housing (12) of a rotation damper (10), and a rotor brake plate (24) provided to be connected to a lower end portion of a rotating shaft (22) of a rotor (20) is rotatably housed inside the housing (12). Also, an O-ring (30) is disposed between the housing (12) and the rotating shaft (22) to prevent the silicone oil (18) from leaking outside of the housing (12). The O-ring (30) is formed by a silicone rubber having a hardness of 25 degrees or above and 45 degrees or less according to the Durometer Hardness Testing (type A) of JIS K 6253.