Combined Insulator and Conductor Assembly for Bearing Current Protection
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Solution Overview
Problem
Bearings in electrical machinery are prone to damage due to electric current or charge passing through them, which existing grounding devices do not adequately prevent.
Innovation Solution
A combined electrically insulator and conductive assembly is used between the shaft and housing, featuring an annular insulator and conductor with conductive fibers to prevent current flow through the bearing while providing an alternative conductive path, thereby protecting the bearing from electrical damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a grounding brush with conductive fibers is used to provide an alternative current path, then current diversion capability is improved, but electrical insulation reliability deteriorates
Solution Approach 1:
The device is divided into two distinct functional segments: an insulator portion that provides electrical isolation and a conductor portion that provides current diversion. This segmentation allows each component to perform its specialized function without compromising the other, resolving the contradiction between insulation reliability and current diversion capability.
Solution Approach 2:
The insulator acts as an intermediary between the bearing and the conductor, allowing the conductor to be positioned near the bearing for effective current interception while maintaining electrical isolation. This intermediary structure enables both insulation and current diversion functions to coexist.
2Reliability
If the conductor is positioned close to the bearing for effective current interception, then current diversion effectiveness is improved, but risk of current arc to the insulator increases
Solution Approach 1:
The insulator serves as a protective intermediary barrier between the conductor and the bearing housing. This intermediary structure allows the conductor to be positioned close enough to the bearing for effective current interception while the insulator prevents harmful electrical arcs from reaching the housing or other components.
Solution Approach 2:
The insulator provides beforehand protection by being positioned between the conductor and potential arc targets. This prior cushioning structure prevents damage before it can occur, allowing aggressive conductor positioning for maximum current diversion effectiveness.
3Object-affected harmful factors
If an annular insulator is placed about the bearing outer ring to block current, then electrical insulation is improved, but current diversion capability deteriorates
Solution Approach 1:
The device merges two previously separate functions (insulation and current diversion) into a single integrated assembly. The insulator portion and conductor portion are combined in one structure, allowing both functions to work together synergistically rather than in opposition.
Solution Approach 2:
The combined assembly is segmented into distinct functional zones: an insulator portion for electrical isolation and a conductor portion for current diversion. This segmentation within the unified structure allows each function to perform optimally without interfering with the other.
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 assembly effectively prevents electric current from flowing through the bearing, directing it safely through the conductive path, thus protecting the bearing from damage and ensuring the machinery's operational integrity.
Implementation Method 1
The insulator is formed of an electrically insulative material or is provided with an insulative layer on at least one of the inner and outer surfaces to substantially prevent electric current flow between the inner and outer rings
Implementation Method 2
An annular conductor has an outer radial end, the outer end being disposed at least partially about the insulator and engageable with the housing inner surface, and an inner radial end engageable with the shaft outer surface so as to provide a conductive path between the shaft and the housing through the conductor inner and outer radial ends
Implementation Method 3
The conductive fibers are spaced circumferentially about the centerline and extend radially inwardly from the inner end of the carrier disk portion. Each conductive fiber has an inner end contactable with the shaft outer surface so as to provide the conductive path between the shaft and the carrier
Data Source
AI summary
A combined insulator and conductor assembly for a bearing disposable between a shaft and a housing includes an annular insulator disposeable about the bearing outer ring and having inner and outer circumferential surfaces and formed of an electrically insulative material or having one or more insulative layers to prevent electric current flow between the outer ring and the housing. A conductive carrier includes a cylindrical portion having an inner surface disposed about the insulator outer surface and an outer surface disposeable against the housing inner surface and a disk portion extending radially inwardly from the cylindrical portion having an inner radial end spaced outwardly from the shaft. An annular conductive brush subassembly is coupled with the carrier disk portion and includes a plurality of electrically conductive fibers contactable with the shaft outer surface to provide a conductive path between the shaft and the carrier, and thereafter to the housing.