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Electrically Insulated Cylindrical Roller Bearings
In motors, generators, and other electric drive systems, stray currents causing damage to bearings are a common and severe challenge. Electrically Insulated Cylindrical Roller Bearings offer an effective solution for such applications. By integrating advanced insulation technology, they fundamentally prevent current flow within the bearing, thereby avoiding electrical pitting, lubricant degradation, and premature failure.
- Alumina Ceramic Coating (Al2O3): A dense, high-resistance aluminum oxide layer is formed on the outer or inner ring surface of the bearing via plasma spraying, providing reliable electrical insulation.
- Excellent Dynamic Characteristics: The inherent line contact design of cylindrical roller bearings gives them outstanding radial load capacity and high-speed adaptability, ensuring mechanical performance is not sacrificed while providing insulation.
- Enhanced System Reliability: Effectively mitigates shaft current problems caused by motor startup, inverter operation, and poor grounding, significantly improving the operational stability and reliability of the entire drive system.
- Reduced Total Cost of Ownership (TCO): By eliminating failures caused by electrical corrosion, it reduces unexpected downtime, component replacement, and maintenance work, optimizing operational costs.
- Customized Solutions: Various configurations such as single-side insulation and double-side insulation are available to meet specific voltage levels, installation space, and environmental requirements.
Technical Specifications
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Parameter
|
Specification
|
|---|---|
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Bore Size Range |
Inner diameter ranging from 20mm to 600mm, supporting both standard and non-standard customization. |
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Interchangeability |
Geometric dimensions conform to ISO 15:2017, fully interchangeable with corresponding insulated bearing series from mainstream brands such as SKF (INSOCOAT® series, e.g., VA201, VA208 suffixes), FAG (e.g., J20AA, SQ78 suffixes), NSK (VS, VSA suffixes), and NTN (C3S, C4S suffixes). |
|
Coating Location |
Insulating coating can be applied to either the inner or outer ring surface to meet different installation and insulation requirements. |
|
Cage Material |
Stamping steel (J) - general purpose; Solid brass (M) - high temperature/vibration; Polyamide (PA66, TNHA) - high speed/low friction. |
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Internal Clearance |
Provides multiple clearance options such as C0, C2, C3, C4, C5, with C3/C4 recommended for optimized performance. |
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Sealing Options |
Open type, contact seals (RS, 2RS) or non-contact labyrinth seals. |
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Breakdown Voltage |
Single-layer coating can withstand up to 1000V DC, special thickened or double-layer insulation can reach 3000V DC or higher, with each batch strictly tested. |
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Electrical Resistance |
Minimum resistance value is typically > 50 MΩ, and can reach several GΩ under ideal conditions, effectively blocking current. |
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Coating Material |
Mainly plasma sprayed aluminum oxide ceramic (Al2O3), also available with silicon nitride (Si3N4) ceramic rolling elements. |
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Coating Thickness |
Standard thickness is 100 µm - 500 µm, customizable to meet higher voltage requirements, but tolerance adjustments will be necessary. |
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Coating Hardness |
Alumina coating microhardness reaches 700-1000 HV, providing wear and scratch resistance. |
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Operating Temperature |
-40°C to +150°C (-40°F to +302°F), with stable insulation performance at high temperatures. |
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Standards Compliance |
Complies with ISO 15:2017, ISO 492:2014 (dimensions/accuracy); IEC 60034-18-42 (electrical insulation); RoHS Directive (environmental protection); ISO 9001 (quality management). |
|
Custom Solutions |
Supports customized services for special sizes, insulation levels, retainers, clearances, etc.; provides insulation spray modification services for existing qualified bearings. |
Key Features & Benefits
Model Numbers
Typical Applications
Wind Power Generators
During operation, wind power generators are highly susceptible to shaft currents due to variable frequency drives, internal electromagnetic effects within the generator, and complex electrical grounding environments within the nacelle. These currents can pass through bearings, causing electrical erosion damage and severely impacting the lifespan of main shaft bearings and gearbox bearings. Electrically insulated cylindrical roller bearings are critical components in such large-scale equipment, ensuring long-term reliable operation.
Key Benefits
- Eliminates Electrical Erosion Damage
- Extends Equipment Lifespan
- Reduces Maintenance Costs
Pumps and Compressors
In equipment such as large pumping stations, air compressor stations, and refrigeration units, if the drive motor is controlled by a frequency converter, it can also generate shaft currents that may damage bearings. The continuous operation of these devices demands extremely high reliability, as any downtime can lead to significant economic losses. Electrically insulated cylindrical roller bearings play a vital role in these applications.
Key Benefits
- Ensures Continuous Operation
- Reduces Maintenance Costs
- Optimizes Energy Efficiency
General FAQ
Find quick answers to common inquiries about our technology, product compatibility, and ordering process.
Do TFL's electrically insulated bearings have sealing functions? Does it affect insulation performance?
Yes.
TFL's electrically insulated cylindrical roller bearings are available in open configurations or with various sealing options. For insulated bearings, we generally recommend non-contact or low-friction seals (such as labyrinth seals or certain non-contact sealing rings) to minimize potential wear or contact between the sealing lip and the insulating coating, thereby ensuring the integrity of the insulation layer remains unaffected. If you require highly dust and water-resistant sealing, we can provide complementary external sealing solutions that protect the bearing without sacrificing insulation performance.
How does the coating position (inner or outer ring) affect performance? How should I choose?
The choice of coating position primarily depends on your equipment structure, installation method, and specific insulation requirements.
The insulating coating can be applied to either the inner or outer ring of the bearing.
Our technical team can provide professional selection advice based on your specific application.
The insulating coating can be applied to either the inner or outer ring of the bearing.
- Outer ring coating: This is the most common configuration, suitable for most applications, and facilitates installation and inspection.
- Inner ring coating: This is suitable for specific applications where effective insulation of the outer ring is difficult, or where more direct insulation of the shaft is required.
Our technical team can provide professional selection advice based on your specific application.
Besides standard products, does TFL support customized insulated bearings?
Yes, TFL offers comprehensive customization services.
We provide two main types of customization:
- We can design and manufacture entirely new electrically insulated bearings based on your special requirements (such as non-standard sizes, unique insulation levels, special cage materials, or internal clearance).
- We also support professional insulation spray modification of your existing or designated qualified bearings. This allows you to maximize the use of existing bearing inventory or specific brand preferences, and upgrade their functionality with our insulation technology, thereby effectively controlling costs and shortening delivery times.
What is the coating hardness of TFL electrically insulated cylindrical roller bearings? Is it easily damaged in daily use?
The coating has extremely high hardness and is not easily damaged in daily use.
The alumina ceramic coating used in TFL electrically insulated bearings boasts extremely high hardness, with microhardness (HV) typically reaching 700 to 1000 HV, which is significantly higher than ordinary steel.
This high hardness provides the coating with excellent wear and scratch resistance, enabling it to effectively withstand minor mechanical contact and wear in normal installation and operating environments, thereby ensuring the long-term integrity and reliability of the insulation layer.
