Composite bearings advantage in terms of accuracy

Composite rotary bearing its high precision, good rigidity, high capacity, no wear and durability. Here is the hydrostatic bearing NTN explore and try a few lessons learned during maintenance:
1. Orifice device:
(1). The external internal throttle to throttle, and to install the upper and lower chamber pressure gauge real-time display. Make maintenance easy, in particular, can easily be cleaned regularly, this is an internal restrictor incomparable.
(2) The throttle ratio. Throttle than the theoretical value of β is between 1.2 to 1.5, and 1.25 based on years of experience preferred. Such maintenance, the need for geometric precision spindle, front and rear pad geometric accuracy, concentricity, roundness and taper strict control in order to guarantee the value of β. Determine the value of e (the eccentricity amount of the spindle and bearing geometric center) in accordance with the carrying capacity of the machine, so that the best value β.
(3) Each oil chamber when the spindle is not loaded, the oil port of each column must be consistent oil (observation). If not, should be taken to change the method of the restrictor aperture to change its flow. In the chamber 4 as an example, generally, the left, the right chamber of the oil column between 20 ~ 25mm, pore diameter of 0.25 ~ 0.4mm.
2. The fuel supply system improvements:
NTN hydrostatic bearing oil supply system, in addition to coarse filter, fine filter, the remaining elements of the hydrostatic bearing NTN has a protective effect. In the original system on the basis of the fuel supply system improvements.
(1) The ground pressure switch and pressure gauge in the throttle plate after the oil port (the original front in the accumulator), which allows the operator to see the size of the chamber pressure and stress. When the pressure is greater than a certain value, in order to immediately shut down to avoid locking bush. Such as: pressure 2MPa, export chamber pressure 1.2 ~ 1.6MPa, 1.2MPa lower than is necessary to stop. (2) increase the digital detection devices:
Between the spindle and bearing hydrostatic bearing NTN clearance 0.04 ~ 0.05mm, during which the oil has a certain resistance value, detect changes in this resistance, it is possible that the size of the gap. In a spindle pole, bearing another pole, measure the resistance change. After processing this signal sent to the photoelectric alarm and control system amplifier controls the spindle motor start and stop, in order to avoid friction axis and tile.