September 27, 2006

NTN Develops Electro-conductive "Hybrid Bearphite EC"

[This design adds a conductive, low-friction, high-precision surface ideal for soft shaft materials to the original hybrid structure of plastic and sintered metal.]

The NTN Corporation (hereafter, NTN) has been mass-producing its "Hybrid Bearphite" high-precision, low-friction sliding bearing with unique hybrid structure of sintered metal and plastic since March 2005. Recently, however, NTN has developed a new product called "Hybrid Bearphite EC"(Note 1) with electro-conductive properties that eliminate electrostatic charges.

The "Hybrid Bearphite" high-precision, low-friction sliding bearing was designed as a substitute for rolling bearings. This unique bearing is formed with a thin plastic sliding material on the inner diameter of the sintered metal. This design gives the required precision (roundness and circularity of 10 microns or less) by means of a custom filler material in the plastic and it delivers a low rotational torque. These features make it ideal for toner image developer units and conveyor rollers in printers as well as photosensitive drum units where it was impossible to use sliding rolling bearings up until now.

However, now there is a demand for electrically conductive bearings for use in some models and by certain users in the market. The plastic layer in the conventional "Hybrid Bearphite" is an insulating material that does not conduct electricity and cannot fill this market need. NTN, therefore, developed the electrically conductive "Hybrid Bearphite EC" by mixing carbon nanoparticles into the plastic material.

(Notes1)

EC = electrical conductivity

[Features]

High rotational precision (same level as oil-impregnated sintered bearings)
- Achieved by forming a thin plastic insert on the sintered metal inner diameter
Low friction (friction coefficient μ = 0.10)
- Friction coefficient slashed to 1/2 that of conventional electro-conductive plastic by hyper-sliding material in the plastic on the inner diameter.
Electrically conductive (volumetric resistance = 3×103³Ωcm)
- Carbon nanoparticles are mixed into plastic on bearing inner diameter to make material conductive for removing electrostatic charges
Compact design (lower cross sectional area than rolling bearings)
- Dual layer structure of sintered metal and plastic allows an extremely simple internal structure

[Sizes Available]

Feel free to consult us
if you need a bearing with low cross section made to custom dimensions.
This bearing has already been used as a substitute for rolling bearings in the following sizes 6×12×4 (WBC6-12), 8×12×3.5 (W678), and 10×15×4 (6700), etc.
[I.D ×O.D.× width (JIS rolling bearing No.)]

[For more information, please contact:]

Planning and Marketing Department, Industrial Sales Headquarters

Engineering Department, NTN Powder Metal Corporation

[Product photo]

[Customer Appeal Points]

·Low Torque	:	Low friction coefficient μ = 0.10
	⇒	Special filler cuts electrical conductivity to 1/2 that of ordinary electro-conductive plastic
·Electrically conductive	:	Volumetric resistance=3×10³Ωcm
	⇒	Carbon nanoparticles make the bearing electrically conductive
·Compact	:	Lower cross section than roller bearings
	⇒	Design allows for small cross section dimensions

[How Bearphite EC was made]

Plastic sliding material was formed on inner diameter of sintered metal
- ·Okay for use with high-precision and soft shaft materials
Custom filler was used on inner diameter surface in plastic sliding material
- ·Low friction (0.10 microns)
Carbon nanoparticles were used on inner diameter surface in plastic sliding material
- ·Electro-conductive: Volumetric resistance = 3,000 ohms per centimeter