An Aerostatic Thrust Bearing with Novel Porous Resistor

• Main Authors: Wan-Yu Lai, 賴婉瑜
• Other Authors: Sy-Wei Lo
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/30196896445797139503

碩士 === 國立雲林科技大學 === 機械工程系碩士班 === 99 === Among various types of resistor, the porous resistors can offer good stability (damping effect) and high load capacity. Therefore in this thesis a novel porous resistor is designed and implemented in an aerostatic thrust bearing. The new resistor consists of a porous material tube and a transportable pin, which is inserted inside the tube. By adjusting the depth of the pin, thereby the size of the air chamber in the tube, the volume rate of the supply air flowing through the porous tube can be tuned to achieve different load capacity or static stiffness for the aerostatic thrust bearing. The load capacity, supply pressure and air gap are detected by the load cell, pressure transducer and laser displacement sensor, respectively. All the data are collected by using a DAQ Card and programmed using the LabVIEW software. The experimental results show that for the biggest air chamber, even in the case of low supply pressure of 2 bar, the bearing can provide 10~20 kgf load capacity with stiffness as high as 1.7 kgf/μm；the medium pin depth (about half of the tube length) however, shifts and cuts down the high stiffness area to 10~15 kgf under supply pressure 3~4 bar；finally the greater pin penetration leads to two high stiffness areas where the load capacities are equal to 20~25 kgf and 10~15 kgf respectively. On the other hand, the relations between the air gap and the pin depth show that under low load of 5 kgf, there are two “sensitive” areas where the air gap changes rapidly with the pin depth; increasing the load up to 10 kgf results in single one sensitive area where the pin depth is around 4~5 mm；at last, for load beyond 15 kgf, this area moves to 1~2 mm. According to the characteristics mentioned above, it can be shown in the thesis that a supreme control (1~2 μm/mm) on the air gap of the thrust bearing can be obtained via regulating the depth of the pin outside the sensitive areas.