Long Lifetime and Low Torque Ultra-clean NC Bearing

NTN Corporation has developed the new Ultra-clean NC Bearing used for semiconductor/LCD manufacturing devices and other vacuum environments. These bearings provide three times the lubricant lifetime and one-half the rotating torque of other similar bearings.

NTN has long manufactured ultra-clean bearings using a thin fluorine resin film coating, and pre-lubricated fluorinated grease. The short life of film coatings and the out-gassing of fluorinated grease, however, are shortcomings in light of current market needs. As a result, these types of bearings are unable to satisfy the demands of the market.

The new Ultra-clean NC Bearing, from NTN, incorporates a newly developed oil-impregnated porous resin cage. This cage employs a special manufacturing method to raise the porosity from the conventional limit of 20% to over 35%. The large volume of lubricant oil contained in the cage is supplied to the bearing over longer periods of time. This results in more than three times the lifetime (compared to prior NTN products), even in high-load applications, and one-half the torque (compared to prior NTN products), through reduction of the lubricant oil's stirring resistance.

Additionally, a low vapor-pressure hydrocarbon lubricant is used. This lubricant does not release toxic fluoride (CF3) out-gas. It also has low reactivity with bearing steel, thus preventing scratches on the raceway and consequentially increasing the bearing life.

Volume sales will begin in one year.

[Features]

1. Long lifetime
• Lasts 3 to 20 times longer than fluorinated grease pre-lubricated bearings
• Lasts 10 to 100 times longer than NTN ultra-clean bearings
2. Low torque
• One-half the torque of fluorinated grease pre-lubricated bearings and ultra-clean bearings
3. Excellent anti-out-gas and anti-dust characteristics
• Does not release toxic fluoride3 gas
• Same low-dust levels as ultra-clean bearings

[Applications]

• Motors of devices used in a vacuum environment, such as conveyors for semiconductor/LCD manufacturing units.

* Ultra-clean NC Bearing:

A member of NTN's Ultra F series of special-environment bearings, achieves longer lifetimes and lower torque through a Network Cell of micropores in an oil-impregnated porous resin holder.

[Product Photo]
Ultra-clean NC Bearing:
608 (inner diam. 8 mm; outer diam. 22 mm; width 7 mm) (left)
and newly developed oil-impregnated porous resin cage (right)

[Product Features]

[Test Data Performance]

<Durability Test>[Surface Pressure Comparison]

<Vacuum-dust Test>

[Design Results]

[Expanded View of Surface of Newly Developed Cage]