Characteristics of hydrostatic bearing for high speed centrifuge
Hydrostatic bearing is a kind of sliding bearing which relies on external supply of pressure oil and establishes hydrostatic bearing film in bearing to realize liquid lubrication. Hydrostatic bearing always works under liquid lubrication from start to stop, so it has no wear, long service life, low starting power, and can be applied at very low (even zero) speed. In addition, this kind of bearing also has the advantages of high rotation accuracy, high oil film stiffness and oil film oscillation suppression, but it needs special oil tank to supply pressure oil, so it consumes more power at high speed.
Advantages of hydrostatic bearing for high speed centrifuge:
1. Pure liquid friction, low friction resistance, low power consumption and high transmission efficiency.
2. During normal operation and frequent start-up, there will be no wear caused by direct contact between metals, with good precision retention and long service life.
3. Because the floating of shaft diameter is realized by the pressure of external oil, it has higher bearing capacity under various relative motion speeds, and the influence of speed change on oil film stiffness is small.
4. The lubricating oil layer has good anti vibration performance and the shaft runs smoothly.
5. The oil film has the function of compensating error, which can reduce the influence of manufacturing error of shaft and bearing itself, and the shaft rotation accuracy is high.
It is very difficult for roller bearings to operate normally in this speed range of high-speed centrifuges from 8000 to 30000r / rain. At high speed, the bearing temperature rises and the oil film disappears, which leads to the bearing damage in a short time. Therefore, high-speed centrifuges generally use hydrostatic bearings with cooling measures.