High-precision navigation platform bearings can be divided into three types: marine navigation platform bearings, rocket-used navigation platform bearings and missile-used navigation platform bearings. It is required that the bearings must have long service life (more than ten years), high precision, high reliability, and excellent resistance to corrosion and impact. When the bearings are working at a low speed or swinging, the working or storage temperature is kept from -40℃ to +80℃.
As for the model selection, generally, the bearings used on the attachment end are angular contact ball bearings, and the bearings used on the movable end are angular contact ball bearings or deep groove ball bearings.
As for the ring thickness, the bearings with thin ring thickness and light weight are often used. The lubrication can be done by the bearing itself, which is normally for only once. It is required that the friction torque must be little and even, of which the coefficient of friction is about 0.0015.
As for the matching of the bearings, in order to guarantee the consistency of the functions, it is required that the difference of the two contact angles of the two bearings in pairs should be less than 0.5°, and the difference between two diameters should be less than 2μm. The rigidities should be close.
As for the installation, the bearings in pairs should be installed with preload which is calculated according to the quality of the navigation platform and the requirement of the rigidity of the bearings.