Conductive Seal Lip Structure for High-Speed Shaft Contact
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Solution Overview
Problem
Conventional electrically conductive rubber seals fail to maintain conductivity at high rotational speeds due to reduced contact area and increased friction, leading to electromagnetic noise interference and electrolytic corrosion.
Innovation Solution
A sealing device with an electrically conductive elastic body unit that includes a lubricant-filled groove system to maintain electrical contact and form a conductive circuit, even at high speeds, using a reinforcing ring and annular continuity lip to ensure consistent conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electrically conductive rubber seals are used, then sealing function is provided, but electrical conductivity deteriorates at high rotational speeds
Solution Approach 1:
The sealing device is divided into multiple functional components: an electrical continuity lip specifically for maintaining electrical contact, a seal lip for sealing, and a backup ring for support. This segmentation allows each component to optimize its specific function, with the electrical continuity lip designed to maintain conductivity even at high rotational speeds while other components handle sealing and structural support.
Solution Approach 2:
Different regions of the sealing device have different material properties and functions. The electrical continuity lip is made of electrically conductive material with specific hardness and elasticity to maintain contact at high speeds, while other portions may have different properties optimized for sealing or structural support. This local differentiation of material quality enables the device to maintain electrical conductivity where needed while performing other functions elsewhere.
2Reliability
If the sealing device maintains contact with the rotating inner peripheral member, then electrical conductivity is improved, but friction and wear increase
Solution Approach 1:
A lubricant is introduced as an intermediary substance between the electrical continuity lip and the rotating inner peripheral member. This lubricant layer reduces direct friction and wear between the contact surfaces while still allowing electrical conductivity to pass through. The lubricant acts as a mediator that enables both low friction and electrical conduction simultaneously.
Solution Approach 2:
The device utilizes changes in material parameters such as hardness, elasticity, and electrical conductivity to optimize performance. The electrical continuity lip is designed with specific hardness and elastic modulus to maintain contact pressure for conductivity while minimizing wear. The material parameters are carefully selected and controlled to balance electrical performance with friction and wear resistance.
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 sealing device maintains electrical conductivity within a range of 0.01 Ω to 100 Ω, reducing electromagnetic noise interference and electrolytic corrosion, even at rotational velocities up to 60 m/s.
Implementation Method 1
the electrically conductive elastic body unit is able to come into contact with the inner peripheral member and the outer peripheral member and form an electrically conductive circuit between the inner peripheral member and the outer peripheral member
Implementation Method 2
the sealing device further comprises a lubricant with electrically conductive, the lubricant is interposed between the electrical continuity lip and the inner peripheral member
Data Source
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AI summary
A sealing device capable of maintaining an electrically conductive performance relative to even an inner peripheral member rotating at a high speed is provided. The sealing device (1) includes an electrically conductive elastic body unit (2) that is an annular member and that includes a portion made of an elastic material with electrical conductivity. The electrically conductive elastic body unit (2) is able to come into contact with a shaft (101) of an electric motor and a housing (102). The electrically conductive elastic body unit (2) is able to form an electrically conductive circuit (3) between the shaft (101) of the electric motor and the housing (102). An impedance of the electrically conductive circuit (3) during a rotation of the shaft (101) of the electric motor at a circumferential velocity of 60 m/s or less is in a range from 0.01 Ω to 100 Ω.