Electrically Insulated Bearing Assembly With Integrated Dynamic Seals
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Solution Overview
Problem
Electric current between the inner and outer rings of rolling bearings in electric motors can cause damage and generate vibrations, and existing solutions like hybrid rolling bearings with ceramic elements are costly.
Innovation Solution
A bearing system with an insulating sleeve comprising a bushing and an insulating insert made of electrically insulating material, integrated with dynamic annular seals to prevent electric current flow and protect against environmental pollution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hybrid rolling bearings with ceramic rolling elements are used to prevent electric current damage, then the bearing reliability is improved, but the manufacturing cost increases
Solution Approach 1:
An insulating insert is introduced as an intermediary component between the outer ring and the rolling elements. This insert prevents electric current from reaching the rolling elements and raceways, thereby protecting the bearing without requiring expensive ceramic materials. The insulating insert acts as a mediator that blocks the harmful electrical path while maintaining the bearing's mechanical function.
Solution Approach 2:
Instead of using expensive ceramic rolling elements throughout the bearing, the invention uses a relatively simple and cost-effective insulating insert that can be easily manufactured and replaced if needed. This approach substitutes a cheap insulating component for the expensive ceramic solution, achieving the same protective function at lower cost.
2Reliability
If an insulating sleeve with bushing and insulating insert is provided on the outer ring to prevent electric current, then the bearing reliability is improved, but the device complexity increases
Solution Approach 1:
The insulating insert is integrated directly with the outer ring, merging the insulation function into the existing bearing structure. This integration reduces the need for separate insulating components and simplifies the overall device complexity while maintaining the electrical insulation function.
Solution Approach 2:
The outer ring is designed to serve multiple functions: it provides mechanical support for the rolling elements and simultaneously incorporates the insulating insert to block electric current. This multi-functionality reduces the need for additional dedicated insulating components, thereby simplifying the device structure.
3Duration of action of stationary object
If sealing devices are added to the insulating insert to prevent environmental pollution, then the bearing durability is improved, but the device complexity increases
Solution Approach 1:
The sealing devices are integrated with the insulating insert, merging the sealing function into the existing insulating structure. This integration allows the insulating insert to serve dual purposes: electrical insulation and environmental sealing, thereby improving durability without proportionally increasing device complexity.
Solution Approach 2:
The insulating insert is designed to perform multiple functions simultaneously: it provides electrical insulation to prevent current damage and incorporates sealing devices to prevent environmental pollution. This multi-functionality maximizes the utility of a single component, improving bearing durability while minimizing the increase in device complexity.
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 system effectively prevents electric current flow and reduces vibrations while maintaining a cost-effective solution by using a bushing and insulating insert, enhancing the bearing's durability and reducing environmental impact.
Implementation Method 1
The insulating insert is formed from electrically insulating material and is interposed radially between the second ring of the bearing and the bushing
Implementation Method 2
The first dynamic annular seal formed jointly by the first sealing device and by the first ring can be obtained by a narrow passage or narrow passages and/or by friction
Data Source
AI summary
A bearing device includes a bearing having a first ring and a second ring configured to rotate relative to each other about a central axis, a bushing, an electrically insulating insert overmolded between and connecting the bushing and the second ring, and a sealing device mounted on the electrically insulating insert and forming a first dynamic annular seal with the first ring. The electrically insulating insert includes a plurality of circumferentially spaced radially extending retaining hooks that hold the sealing device against a portion of the electrically insulating insert.