Ceramic Bearings

Ceramic Bearings

The ceramic bearings of our company are mainly made up of zirconia (ZrO2), silicon nitride (Si3N4) and silicon carbide (SiC). All ceramic bearings have anti-magnetic and electrical insulation, wear resistance, corrosion resistance, high and cold temperature resistance and other characteristics. Most of retainers are made by PTFE, PEEK, NYLON and other materials, but non-retainer full ball ceramic bearings are also available.

Ceramic bearings have the following advantages:

1, Long life and wear resistance - the life expectancy of all ceramic bearing is 10-50 times longer than the life expectancy of all-steel bearings.  The life of hybrid ceramic bearings is 3-5 times longer than full-bearing steel bearings.
2, 60% lighter than steel and 2 times of high temperature hardness than steel.
3, Corrosion resistance - As the ceramic material is the inert material, it is more resistant to corrosion and wear.
4, Rigidity - Because of the high elastic modulus of ceramic materials, its rigidity is 50-55% more than ordinary steel bearings.
5, High temperature - All ceramic bearings can be used in the environment with a temperature more than 500
6, Low torque - According to the structure, the ceramic bearing torque is reduced by about 1/3;
7, Non-magnetic and non-conductive.

Full Ceramic Bearings  made with ZrO2

All ceramic bearings with anti-magnetic electrical insulation, wear resistance, corrosion resistance, oil-free self-lubricating, high temperature and cold tolerance characteristics can be used for extreme harsh environments and special conditions. The rings and the rolling element are made of zirconia (Zr02) and the retainer is made of PTFE (PTEE) as the standard equipment. Generally, the glass fiber reinforced nylon 66 (GPRA 66-25) and special engineering plastics 


Full Ceramic Bearings  made with SisN4

The rings and rolling elements of silicon nitride all-ceramic bearing are made of silicon oxide (Si3N4) ceramic material and with PTFE retainer as a standard equipment. Generally, the glass fiber reinforced nylon 66 (GPRA 66-25) and special engineering plastics (PEEK , PI) are also available. Comparing to Zr02 material, Si3N4 all-ceramic bearing is more applicable to higher speed and load capacity, and used in higher temperature environment. At the same time, it can be provided to be used on a axle required a high-speed high-precision high-rigidity precision bearing.


Full Ceramic Ball Bearings w/o cage

Due to the non-cage structure design, more ceramic balls loaded than the standard structure bearing is to enhancing its radial load capacity. In addition,  it also can avoid the cage material constraints to achieve anti-corrosion and temperature resistance effects of the ceramic cage type all-ceramic bearings.  However, the series is not suitable for a high-speed condition.   Pay attention when the installation, the the gap surface is not installed in the axial load end.  As the inner and outer ring of bearing with a ball gap, the bearing is not suitable for a larger axial load applications.


Full Ceramic bearings with Ceramic cage

Ceramic cage has the advantages of wear-resistant, high strength, corrosion-resistant and self-lubricating. The all-ceramic bearings with a ceramic cage can be used in the condition of strong corrosion, high temperature and high vacuum and other harsh environments. Commonly, Zr02 is used as the material of ceramic cage.

Properties comparison of ceramic materials

Technical data Unit B4C 99A12O3 ZTA-20% ZrO2 Si3N4 Sic
Density ρ g/cm3 2.4-2.51 3.7-3.99 5.5 6 3.2 3.2
HV Hardness kg/mm 2700-3200 2300-2700 1470-1500 1300-1500 1700-2700 2350-2450
Flexural strength σs Mpa 350-400 300-400 700 1000-1500 900 450-800
Indentation strength Mpa 1800-2500 2800-3500 2000 2000 3500 2250-3000
Impact strength Kc Map.m-3/2 6 2-4 5-6 11 7 4-5
Weber modulus Gpa   >7 >10 >15 >15 >6
Et. modulus of elastcity Gpa   407 260 210 320 410
Poisson ratio     0.2 0.23 0.3 0.26 0.16
Coefficient of expansion α x10-6/℃ 4.5 6.5-8.6 9.4 10.5 3.2 4.3
Heat Impact △T℃   200 470 250 500 350
Resistivity \Omega CM2 0.3-0.8 >1014-1016 >1010 >1010 >1014 100~2


All-ceramic bearings made with ZrO2