Ceramic Ball Bearings
產品頁介紹標題
Ceramic Ball Bearing
Full ceramic ball bearings constructed entirely of ceramic material. Inner/outer races and balls are made of Silicon Nitride (Si3N4) or Zirconium Oxide (ZrO2). They are available as full complement (no cage) or with a cage made from PEEK or PTFE. Full ceramic bearings are for medium load and medium speed applications. It is not possible to achieve the inner and outer ring roundness that is found with precision steel bearings, so full ceramic bearings have lower speed ratings.
Because it can be used in extremely bad environments and special situations, it applies to aviation, seafaring, petroleum, chemical industry, automobile, electronic equipment, metallurgy, electric power, textile, medical device, vacuum equipment, and military affairs field.
Characteristic:
1. Higher hardness and better elasticity compare to standard steel bearings.
2. Full ceramic bearings can be run completely dry.
3. Excellent corrosion resistance allows them to run in concentrated acids, alkalis or submerged in seawater without corroding.
4. More suitable for temperature variation.
5. The life cycle of full ceramic bearings is much longer than steel bearings.
6. Prevent electrical arcing. The natural insulating properties of ceramic material eliminate this type of damage.
Material:
Inner/outer races=> ZrO2、Si3N4
Balls=> ZrO2、Si3N4、Glass
Cage=>PEEK、PTFE、Bakelite、Nylon、Full complement (no cage)
Technical Data:
|
|
Silicon Nitride Si3N4
|
Zirconium Oxide ZrO2
|
Density (g/cm3)
|
3.20~3.30
|
6.05
|
Coefficient of thermal expansion (10-6/k)
|
3.2
|
10.5
|
Elastic modulus (Gpa)
|
300~320
|
210
|
Poisson's ratio
|
0.26
|
0.30
|
Hardness (HRC)
|
75~80
|
70
|
Flexural strength (Mpa)
|
200
|
300
|
Compressive strength (Mpa)
|
1400
|
2100
|
Fracture toughness (Mpa．m1/2)
|
6.0~7.0
|
10.0
|
Thermal conductivity (W/mk)
|
18
|
2
|
Electrical resistivity (Ω•mm2/m)
|
1018
|
1015
|
Max temperature (°C)
|
800
|
550
|
Corrosion resistance
|
High
|
High
|
Dimensional stability
|
High (Not easy to change with temp.)
|
-
|
Dry friction
|
Low
|
Low
|
Magnetic
|
Non
|
Non
|
