The structure of the working principle of the instrument 1.1 instrument the instrument is mainly composed of three parts: the mechanical system and electrical system, sensor.Mechanical system mainly includes: high precision dynamic bearings, shaft, slidingunloading damping system, driving device, standard device. 1.2 working principle, a plug is inserted into the required anterior taper spindle, the measured bearing onto the mandrel,the adjustment of the contact force sensor probe and the outer surface of the cylindrical to the required pressure. Start the main rod drives the bearing inner ring and the rolling bodyassembly to rotate, and according to the measured bearing type, the axial force exerted on the outer ring of the bearing. The speed sensor signal of bearing radial vibration pickup tothe converted into electrical signals, amplified by the amplifier, a 45Hz high pass filter filters out the 30Hz baseband signal, the measuring range switch into the three RMS bandpass62000.l. filter #23#5 bearing different after amplification by three alternating current meterindicates the bearing vibration velocity of each frequency band (also. The root mean square value) and the peak value of vibration. The 2 key components of the design and choice of 2.1 machine system the main function of 2.1.1 hydrostatic spindle the spindle isunloading bearing motor belt tension, and effectively reduce the vibration transmission tothe sliding shaft, motor testing, selection of 15# lubricating oil, running at a rate of 1800rPmin for long time, the temperature rise is not obvious, and the rigid good.

2.1.2 liquid dynamic pressure bearing and thrust bearing hydrodynamic lubrication radialand thrust bearing is designed according to the theory of fluid mechanics, the reynolds.Dynamic pressure bearings with three oil wedge structure, the axial bearing adopts eight oilwedge hydrodynamic bearing. Radial bearing part is the two-way rotation, axial supportingpart is a one-way rotary. 2.1.3 flexible coupling unit for processing and assembly andspindle system in the heart, and can effectively reduce the amount of additional vibrationwhich leads to the. 2.1.4 unit load device with radial position adjustable elastic measuring claw, which does not limit the bearing outer ring and the outer ring radial vibration is transferred, the axial force value can be adjusted continuously, and can meet the needs of different size of bearing force of variable demand.