Precision Instrument Bearings

Rolling bearings used in all kinds of precision instruments, mostly inner diameter less than 10mm or 30mm outside diameter not greater than ball bearings. Due to the structure of instruments are more compact, so often used in special light or ultra-light size four point contact ball slewing bearing, and require bearings with high reliability, low friction, low noise, and resistance to corrosion, high temperature, magnetic and other properties.
l. Precision instruments bearing structure
(1) deep groove ball bearings and angular contact ball
Instruments used in the most widely used is the deep groove ball bearings and angular contact ball bearings. Its most notable feature is a compact, low friction, rotating flexible, and according to need to use in other aspects of the structure and the tolerance level is selected.
(2) top bearing
Bearing such a strong bearing capacity, low friction torque, often for precision instrumentation framework support bearings.
(3) combined bearings
This kind of bearing no inner or outer ring no, compact structure, small radial dimension, while the deviation due to reduced coaxial rings mounted on the shaft or housing generated by the improved miniature linear bearings and bearing parts stiffness, help to improve the tribological properties of the bearing. However, since the parts in contact with the rolling elements requires high precision, and often require special processing methods and detection equipment, the processing cost is increased. Therefore, these bearings are generally used only for high-speed devices requiring high torque and friction parts.
(4) Multi-ring bearings
Also known as polycyclic bearings. It is generally three to four rings, three balls. Intermediate rings for forced movement, which can be a swing, it can be work-axis continuous rotation opposite. Intermediate swing is called vibration thin wall bearings, called continuous rotation of the rotary bearings. As the middle rings of movement will make the work of the shaft to reduce the friction torque 7 / 8-9 / 10. These bearings are asking for is not high speed friction torque minimal occasions.
2. Magneto-precision bearings
The basic properties of magnetic motor thin section angular contact bearings for precision instruments, such as low noise, smooth running, low friction torque and wear-resistant, are built on the basis of high accuracy. For example, a computer disk drive bearing, its accuracy can not be rotated according to the original provisions of the radial runout tolerance, its tolerance should track pitch high-density disks adapt, usually provides less than 1/4 of the track width, otherwise it will cause the track error.
Also, take the following measures to meet the requirements.
① strict control of the bearing radial clearance to make it work in the pre-load.
② control starting torque and dynamic torque of the bearing, in order to meet the requirements of a magnetic motor control current.
③ guarantee bearing clean, clean work 100 clean bench in the occasional cleaning bearing assembly.
④ control bearing lubricant dust particles less than 0.1 microns in diameter, while also controlling with the growth in use of time, oil deterioration caused by dust particles increases and increased.
⑤ bearing magnetic fluid seal.
3. Ultra-high-speed ball bearings
Ultra-high-speed instrument bearings typically used in high speed cameras, high-speed dental drill, etc. used in bearings, operating speed of up to 105r / min or more, bearing diameter is about 3mm, the intermittent nature of the work is the work of the general requirements for hundreds of hours total working life. Based on the above operating conditions, the choice of these bearings and take appropriate action.
1) selection of bound or ring-type ball bearings.
2) use of small steel balls or ceramic ball bearing design.
3) bearing retainer for non-metallic materials have made white lubricating function.
4) bearing assembly dynamic imbalance rigorous testing required.
5) appropriate bearing preload.