INSULATED BEARING

Get Fastest Delivery / Get Best In Market Rates / 43+ Years Of Experience

Electrically insulated bearings typically have an aluminum oxide-coated outer ring OD face and end faces. Insulated bearings with a coated inner ring bore and end face, these bearings offer increased protection against high frequency currents due to the smaller coated surface area of the inner ring than the outer ring.Insulated bearings prevent premature bearing failures eventually caused by stray electrical currents. Insulation properties must remain stable regardless of environmental conditions, in particular when bearings are stored, handled and operated in humid climates. Bearing damage can occur when electrical currents use the rolling contact as a conducting path. Today, a number of publications are available that deal with this matter, including discussions about root cause and counteractions, for example [1, 2, 3, 4]. The tribological regime of a bearing determines the electrical behaviour of the rolling contact and the possible outcome.In the conductive state the bearing is at a standstill and shows a low ohmic resistance. Due to the relatively good metal-to-metal electrical contact, only very high amperage currents such as welding currents are able to destroy the raceway surface. The resistive state is present if the bearing is in a mixed lubrication regime with increased ohmic resistance. In this regime, low electrical currents in the range of a few amperes have the potential to be dangerous. In the capacitive state the bearing is in a full film lubrication regime, and it acts like an electric capacitor with a specific breakdown voltage. If the applied electric field strength present in the lubrication film of the contact zone is high enough (in excess of the threshold value) electric discharges, called EDM (electric discharge machining) currents, will occur.

Balaji Bearings is a market-leading producer and supplier of Insulated Bearings, delivering specialised solutions for electrical applications. Recognised as a trusted distributor, we serve customers in Sri Lanka, South Africa, the UAE, Nigeria, Egypt, Indonesia, Thailand, and Kuwait. Our insulated bearings are engineered to resist the harmful effects of stray electrical currents, ensuring long-term durability and reliable performance in motors, generators, and other critical applications.

Key Applications of Insulated Bearings

• Electric Motors: Variable Frequency Drives (VFDs) in motors can generate stray currents that damage bearings. Insulated bearings prevent this erosion and extend motor life.
• Generators: Protects main bearings in turbines and power generators from electrical pitting, ensuring consistent performance in critical energy systems.
• Electric Vehicles (EVs): Increasingly used in EV motors and transmissions to block harmful electrical currents, safeguarding the propulsion system for long-term use.
• Traction Motors: Essential in railway and heavy-duty electric traction systems, insulated bearings provide protection against stray current damage to motors and gearboxes.

Characteristics of Insulated Bearings

• Electrical Insulation: Ceramic coating (commonly on the outer ring) acts as an effective insulator, blocking shaft currents from reaching the housing.
• Electrical Erosion Prevention: Prevents pitting and fluting damage commonly caused by stray currents in conventional bearings.
• Corrosion Resistance: The ceramic coating offers exceptional resistance to corrosion, ensuring long-lasting reliability in harsh environments.
• Standardised Dimensions: Designed to match the dimensions and performance of standard bearings, enabling direct replacement without design modifications.