22218 C3W33 Spherical Bearings ZSQ03

Product Overview

SL30 Insulating Long-Lasting Micro Bearings 6000-6003 are specialized precision components engineered to provide electrical insulation while delivering reliable performance in compact machinery. This series covers inner diameters from 10mm (6000 model) to 17mm (6003 model), making them ideal for small electric motors, generators, and precision instruments where space is limited. The key distinguishing feature is their integral insulation system, which prevents electrical current passage between inner and outer rings—critical for protecting sensitive equipment from electrolytic corrosion caused by stray currents. Manufactured to strict precision standards, these micro bearings combine long service life (up to 20,000 operating hours under normal conditions) with exceptional dimensional accuracy, making them indispensable in electrical and medical equipment applications.

Product Features

Insulation Technology

The bearings feature a proprietary aluminum oxide (Al₂O₃) coating on the outer ring and rolling elements, providing an insulation resistance of ≥ 1000 MΩ at 500V DC—exceeding industry standards for electrical isolation. This coating is 50-100μm thick with a hardness of HV 1000, ensuring both electrical resistance and wear resistance. The insulation system withstands voltage spikes up to 1000V AC, protecting against damage from electrical transients in motor applications.

Precision Manufacturing

Produced to ABEC-5 precision grade, these micro bearings offer tight dimensional tolerances: radial runout ≤ 0.005mm, axial runout ≤ 0.01mm, and dimensional variations within 0 to -0.008mm for inner diameter. The raceways are precision-ground to a surface roughness of Ra ≤ 0.01μm, minimizing vibration (≤ 45dB at 3,000 rpm) and ensuring smooth operation in noise-sensitive applications. Each bearing undergoes 100% inspection for insulation integrity before leaving the factory.

Material & Durability

The base material is high-purity chrome steel (GCr15SiMn), heat-treated to achieve surface hardness of HRC 60-64 for wear resistance and core hardness of HRC 30-35 for toughness. The cages are made from glass fiber-reinforced nylon 66, which offers low friction, good chemical resistance, and dimensional stability across temperature ranges. This construction enables the bearings to withstand static radial loads up to 14.5 kN (6003 model) and dynamic radial loads up to 9.8 kN.

Applications

Electric Motors & Generators

In fractional horsepower motors (0.1-1.5kW) used in household appliances and industrial fans, these bearings prevent electrolytic corrosion caused by shaft currents, extending motor life by up to 300% compared to standard bearings. The 6002 model (15mm ID) is particularly popular in inverter-driven motors, where variable frequency drives create stray currents that would damage conventional bearings.

Medical Imaging Equipment

MRI machines and CT scanners utilize the 6003 model (17mm ID) in their rotation mechanisms, where the insulating properties prevent interference with imaging signals. The low vibration characteristics (≤ 40dB) ensure quiet operation, while the compact size fits within the confined spaces of medical equipment housings. The bearings' material compatibility with MRI environments eliminates ferromagnetic interference.

Precision Instrumentation

Used in optical encoders and laser positioning systems, the 6000 model (10mm ID) provides stable rotation with minimal runout, ensuring measurement accuracy within ±0.001mm. In laboratory centrifuges, these bearings maintain balance at speeds up to 8,000 rpm while isolating electrical components from stray currents generated by variable speed controls.

Renewable Energy Systems

In small wind turbine generators (≤ 10kW) and solar tracking systems, the bearings withstand outdoor conditions while preventing electrical corrosion from ground faults. The 6001 model (12mm ID) reliably operates in temperature extremes from -40°C to +120°C, making it suitable for diverse climate conditions.

FAQ

Installation & Testing

How to verify insulation performance after installation?

Use a megohmmeter to measure insulation resistance between the inner and outer rings at 500V DC—values should remain ≥ 1000 MΩ. Test before and after installation to ensure handling hasn't damaged the insulation coating. Avoid using conductive lubricants or tools that could compromise the insulation system during installation.

What special handling precautions are required?

The insulation coating can be damaged by impact or excessive force. Use plastic or non-metallic tools during installation, and avoid pressing directly on the outer ring. Store bearings in their original packaging until ready for use, and handle only by the inner ring when possible. Never use sandpaper or abrasive materials on any bearing surfaces.

Performance & Limitations

What causes insulation resistance to decrease?

Moisture absorption is the primary cause—insulation resistance may drop temporarily in high humidity (> 85% RH) but should recover when dry. Permanent decreases indicate coating damage from mechanical impact, chemical exposure, or excessive temperature. If resistance falls below 500 MΩ, replace the bearing to prevent equipment damage.

Can these bearings be used in high-frequency applications?

Yes, they maintain insulation integrity at frequencies up to 100kHz, making them suitable for inverter-fed motors and high-frequency machinery. For applications above 100kHz, consult technical specifications, as insulation performance may vary with frequency and temperature.

size