Insulated Bearings

Product Details:

SKF Insulated Bearing are designed to prevent current from passing through the bearing. The bearings are a very cost-effective solution compared with other insulation methods. By integrating the insulating properties into the bearing, SKF INSOCOAT bearings can improve reliability and increase machine uptime by virtually eliminating the problem of electrical erosion.

Insocoat Bearings:

Electric motors, generators and associated equipment are at risk when an electric current passes through a bearing. This can damage the contact surfaces of rolling elements and raceways in the bearing (electrical erosion) and rapidly degrade the grease. An additional risk in electric motors and generators comes from high frequency currents due to the inherent stray capacitance. The risk of damage increases if the application uses a frequency converter.

Insocoat Bearings:

An SKF Insocoat bearing is a standard bearing that has the outside surfaces of its inner or outer ring plasma-sprayed with an aluminium- oxide to form a coating. The coating is sealed with a resin to protect against the conductive effects of water and moisture. The basic coating can withstand voltages up to 1 000 V DC. However, coatings to withstand voltages up to 2 000, or even 3 000 V DC can be supplied on request.

Insocoat bearings with a coated outer ring:

Insocoat bearings typically have the outside diameter and side faces of the outer ring coated with aluminium-oxide. These bearings are identified by the designation suffix VL0241.

INSOCOAT bearings with a coated inner ring:

Insocoat bearings that have the bore and side faces of the inner ring coated are identified by the designation suffix VL2071. These bearings provide enhanced protection against high frequency electric currents due to the smaller coated surface area of the inner ring compared to the outer ring.

Assortment:

The standard assortment of insocoat bearings constitutes the most commonly used sizes and variants of:

• Single row deep groove ball bearings
• Single row cylindrical roller bearings

Product Details:

NKE Insulated Bearing - Optimum protection against bearing damage caused by the passage of currents. NKE insulated bearings reliably prevent current discharge. NKE provides bearings with oxide ceramic insulating layers on the bearing ring. Applied with plasma technology, the insulation has a guaranteed breakdown resistance of at least 1000V AC or DC.

Two variants are available:

• SQ77: Insulation on the outer ring
• SQ77E: Insulation on the inner ring

Product Range:

• Cylindrical roller bearings - Design variants: NJ, NU, NUP; Dimension series: 210-230, 310-330; Cages: brass and polyamide; Radial clearance groups: C0, C3, C4
• Deep groove ball bearings - Dimension series: 6212-6226; 6312-6326; Cages: brass; Radial clearance groups: C3, C4
• Other types and SQ77E (insulated inner ring) upon request

Advantages:

• Higher operational reliability through optimum protection against electrical corrosion
• More economic than, for example, insulation on housings or shafts
• Interchangeable: Same key dimensions and technical properties as conventional bearings
• Coating resistant to damage if correctly handled

Typical Applications:

• Traction motors of railway vehicles
• Electric motors (AC/DC)
• Generators (e.g. in wind turbine generators)

Product Details:

AKN maintains its own production facility in Germany for bearings in special designs that are not or no longer offered by the major manufacturers or for which large minimum order quantities are required.

AKN Products:

• Ball-Bearing:

 Due to its design, the deep groove ball bearing is the most common design and is used in a large number of different applications.
It not only absorbs radial forces, but also axial forces in both directions.
Thanks to the low frictional torque, deep groove ball bearings are also suitable for high-speed applications that require low power losses. They are easy to assemble and can be used in many different configurations.

• Roller Bearings:

 Roller bearings absorb high radial and medium axial forces and are wear-resistant despite the possible vibration. They are highly insensitive to misalignments and impact loads. 
The quality features include the high manufacturing accuracy of the bearing parts. 

• Housing Bearings:

The housings are available with numerous special seals and covers for a secure seal. They can be equipped with powerful spherical roller bearings or with spherical ball bearings. 
As standard, they are made of high-strength cast iron, but are also available in cast steel or cast iron with spheroidal graphite.The housings are provided with a device for relubrication with oil or grease.

• Plain and Spherical Bearings:

1. Plain Bearings - sliding elements made of composite material. Suitable for rotating and swiveling movements.Available in a maintenance-free or low-maintenance version.
2. Spherical Bearings and rod ends are standardized, ready-to-install machine elements primarily for oscillating and swiveling movements.

• Freewheels:

Freewheels are directional clutches that transmit torque in one direction and allow idling in the opposite direction.

Product Details:

To prevent such damage, the FAG offers current-insulated bearings:

• Current-insulated bearings and hybrid bearings
• Current-insulated bearings have either an outer ring (J20 A, J20 AA, J20B) or an inner ring (J20C) that is insulated with thin ceramic coating
• Different coating types are available for optimum functional performance

Types of coatings - Range of Sizes:

• Disruptive voltage 500 VDC 1000 VDC 1000 VDC 1000 VDC
• Environment dry dry dry/damp dry/damp
• Coating thickness 200 μm ≈200 μm ≈200 μm

Preferably used for bearings with an outside diameter of at least 500 mm:

• Current-insulated bearings have the same dimensions and load carrying capacities as those without insulation, which makes them perfectly interchangeable
• The most common type of insulation used in electric motor applications is the J20AA coating. It offers excellent protection against passage of electrical current, even in damp atmospheres
• Bearings with ceramic coating are available with seals also
• Bearings with J20C coating on the inner ring are used in special applications as well as applications where the outer ring rotates. Z shields can be used as well

Ordering Examples:

6220-2RSR-J20AA-C3:

• Deep groove ball bearing with a coated outer ring, with seals on both sides and radial clearance C3.

NU214-E-M1-F1-J20B-C4:

Cylindrical roller bearings with a coated outer ring and radial clearance C4.

6330-J20C:

• Deep groove ball bearings with a coated inner ring

Hybrid bearings (HC): Hybrid bearings are characterized by the fact that the rolling elements are made of ceramic. They offer maximum protection against passage of electrical current. At the same time, hybrid bearings are suitable for higher speeds and have better dry-running characteristics.

Ordering Examples:

HC6214-M-P6-C3:

• Deep groove ball bearing with ceramic balls; machined brass cage; increased accuracy P6 and bearing clearance C3.

HCN1020-K-M1-SP:

• Cylindrical roller bearing with ceramic rollers; tapered bore; machined brass cage; increased accuracy SP.

Product Details:

AC motor bearings are vulnerable to the formation of fusion craters that can lead to frosting, pitting, fluting and eventually bearing failure. This type of premature failure can cost thousands of dollars in increased maintenance and lost production. AEGIS SGR Bearing Protection Ring prevents electrical damage to motor bearings by channelling harmful shaft currents to ground.

Our patented AEGIS® bearing protection, grounding technology consists of a Conductive MicroFiber™ shaft grounding ring in an aluminium housing. It is easy to install and maintenance free.

Shaft Grounding Ring™

The use of variable-speed drives with AC motors induces electrical currents on the motor shaft. Once they exceed the resistance of the bearing lubricant, these currents discharge to ground (typically the motor housing), causing fusion craters in the bearings. Over time, these craters increase in size and number, resulting in frosting, pitting, fluting, and eventually bearing failure. This type of premature bearing failure can cost thousands of dollars in increased maintenance and lost production - we can offer a solution.

AEGIS® SGR

The new AEGIS® SGR Conductive MicroFiber™ shaft grounding brush prevents electrical damage to motor bearings by safely channeling harmful shaft currents to ground. Using proprietary Electron Transport Technology™, the conductive microfibers inside the AEGIS® SGR provide the path of least resistance for damaging shaft currents, preventing electrical damage to motor bearings and dramatically extending motor life.

Not only is the AEGIS® SGR the world’s most effective grounding brush, it offers the longest lasting protection available.

• Maintenance-free
• Unaffected by dirt, grease, or other contaminants
• Lasts for life of motor
• Easily installed in minutes— even in the field
• Mounts on either end of motor shaft
• Simple screw-on mounting brackets
• No machining required

We offer 3 options for shaft bearing protection

Aegis® SGR; for small to medium sized motors - For up to 10 amps- shaft diameters exceeding 152 mm- available in solid and split designs

AEGIS® WTG for wind turbine generators - High current capability 120- amp continuous current and 3000 volt peak- retrofitting with split ring option

AEGIS® IPRO for high voltage bearing protection for large motors and generators - High current capability 12- amp continuous current and 3000 volt peak-AEGIS® IPRO shaft current monitoring capability- up 762mm shaft size

AEGIS SGR™ Bearing Protection Ring from Electro Static Technology is the only bearing system guaranteed to eliminate harmful shaft currents, preventing premature motor failure — for life.

 

As variable frequency drives induce electrical voltages onto the shafts of AC and DC motors, they can exceed the resistance of bearing lubricant, leaving your motor's bearings vulnerable to fusion craters, severe pitting, fluting damage, excessive bearing noise and eventually bearing failure.

 

The AEGIS SGR™ Bearing Protection Ring™ safely channels harmful shaft voltages away from the bearings to the ground, dramatically increasing the life of your bearings and motors.