Product Item:Zirconia Ceramic Bearings

Details of Zirconia Ceramic Bearings:

Zirconia all-ceramic bearings have features of magnetoelectric insulation resistance, wear resistance and corrosion resistance, oil-free self-lubrication, high temperature resistance and high cold resistance, so it can be used in harsh environments and special working conditions. Rings and rolling elements are made of Zirconia (ZrO2) ceramic materials, and for material of retainer, polytetrafluoroethylene (PTFE) is standard configuration, generally glass fiber reinforced nylon dragon 66(GRPA66-25), special engineering plastics (PEEK, PI), stainless steel (AISI SUS316, SUS304), brass (Cu), etc. can be also used.

Features:

1. Corrosion resistance: The material itself has corrosion resistance, and can be applied to strong acid other than hydrofluoric acid, strong alkali, inorganic and organic salt, seawater and other fields. It is suitable for working under harsh conditions where is full of corrosive media, such as plating equipment, electronic equipment, chemical machinery, ship manufacturing, medical apparatus and instruments, etc.

2. High temperature resistance: between 180℃ and 260℃, ceramic bearings with retainers will not have expansion due to temperature difference. Working temperature of zirconia ceramic bearing filled with balls is between 300℃ and 800℃, and can be applied to high temperature equipment like furnace kilns, plastic and steel manufacturing devices.

3. Self-lubrication: Ceramic bearings have good self-lubricating property for their small friction coefficient and good surface smoothness, especially silicon nitride material, whose self-lubricating performance is excellent. Therefore, ceramic bearing do not need any grease. Under vacuum environment, problem of lubrication for ordinary bearings can be overcome with application of ceramic bearing.

4. Anti-magnetism: Because there is no magnetism and without dust absorption, so problem of early peeling off and loud noise can be reduced, for which it can be used in fields of demagnetization equipment and instruments.

5. Electrical insulation: due to its high resistance, arc damage to bearings can be avoided, so it can be used for power equipment with insulation requirement.

6. Density of ceramic rolling balls is lower than that of steel and their weight is much lighter, therefore, the centrifugal effect on the outer ring during rotation can be reduced by 40%, thus greatly prolonging the service life.

7. Ceramic is less affected by heat expansion and cold contraction than steel, so with constant clearance, bearing can be allowed to work in environment with severe temperature difference.

8. The elastic modulus of ceramics is higher than that of steel, and it is not easy to deform under stress. Therefore, it is conducive to improving the working speed and achieving higher precision.

Instructions for installation and use of ceramic bearings.

Deep groove ball bearings-- Size details (Click this button)

Inch size ball bearings--Size details (Click this button)

Angular contact ball bearings--Size details (Click this button)

Double row angular contact ball bearings--Size details (Click this button)

Self-aligning ball bearings--Size details (Click this button)

Single direction ball bearings--Size details (Click this button)

Insert bearing--Size details (Click this button)

Performance parameters:

Properties comparion of all kinds of bearing

Installation of Ceramic Bearings:

When install bearings, equal pressure must be exerted on the circumference of the ferrule end face. In order to install the ferrule, it is forbidden to directly hit the bearing end face with a hammer or other heavy device, so as not to damage the bearing. In addition, if exert force to one side of the ferrule (e.g. the outer ring) and press in the other side (e.g. the inner ring) via the rolling body, indentation or scratch on the rolling surface will occur, so this method  should not be used, especially install non-separation bearing on the shaft and bearing box simultaneously.

Coordination of Ceramic Bearings

(1) Magnitude of interference. Fix the inner ring and outer ring of the rolling bearing on the shaft or bearing box, when load is applied to the rolling bearing, there should be no relative movement on mating surface of the ferrule and the shaft or bearing box in radial direction, axial direction or rotation direction. This kind of relative movement will cause abrasion, friction corrosion, friction cracks on the mating surface, thus causing damage to bearing, shaft and bearing box.

Furthermore, abrasive dust enter into inside of the bearing and lead to poor operation, abnormal heat generation, vibration, etc. For fixing manner of the bearing, leaving interference on the mating surface of the ferrule and the shaft or bearing box for static fitting. Static fitting can make the load of the thin-walled ring evenly distributed on the circumference without affecting load capacity of the bearing. However, besides inconvenience of assembly and disassembly the bearing, bearing cannot be moved axially from the free side, so static fitting is not suitable to all occasions.

(2) Selection of fitting. Selection of fitting is generally conducted according to the following principles. According to the load direction, property, and rotating part (inner or outer ring), load borne by the ferrule can be categorized as rotating load, static load and non-directional load. Static fitting (interference fitting) should be selected for ferrule that with rotating or non-directional load, and for ferrule with static load, transitional fitting or dynamic fitting (clearance fittting) is preferable. When the load is large, or vibration and impact load is applied, the interference should be increased. If hollow shafts, thin-walled bearing box or bearing box made of light alloy or plastic are used, the interference should also be added. For occasion that high rotational accuracy is required, high-precision bearing should be used and dimensional accuracy of the shaft and bearing box must be increased, and extra interference should be avoided. Since if the interference is too large, geometric accuracy of the shaft or bearing box may affect geometrical shape of the ferrule, thus damaging rotation accuracy of the bearing. If both inner and outer ring of split bearing (e.g. deep groove ball bearing) adopt static fitting, then assembly and disassembly of the bearing will be extremely inconvenient, so either inner or outer ring need to use dynamic fitting.

(3) Recommended fitting. For dimensional tolerance of shaft, bearing box, and bore of assembly bearing, in metric system, corresponding standards have already been defined in ISO286 (Dimensional Tolerance and Fitting). Therefore, fitting tolerance has been determined according to the selected shaft diameter and bore diameter dimensional tolerance.

Shipping:    

We do international shipping for clients.      

Special offer:  Most of our crucibles are produced to order, please mark clearly height, bottom diameter, top diameter, wall thickness and any special requirements i.e. lips etc. To speed up quotations please supply a drawing and if appropriate, the name of the system in which they are to be used.