フルイドダンパを付加したポケット型静圧気体ジャーナル軸受の軸の応答特性

抄録

Pneumatic hammer instability has been the greatest problem in realizing a high stiffness gas bearing with a large pocket in the bearing surface. The authors have already succeeded in realizing a high stiffness and heavy damping hydrostatic thrust gas bearing with a large pocket by the use of fluid damper. In this paper, the shaft response characteristics and static performances in a hydrostatic pocket journal gas bearing are investigated both experimentally and theoretically. The following conclusions are obtained. (1) Fluid damper has a good influence on the improvement of the trangent motion and the prevention of pneumatic hammer instability. (2) When an impact force acts on the shaft, it is possible to make the amplitude of rigid body as small as that of elastic body. (3) A high stiffness journal gas bearing with a large pocket can easily be realized by the use of fluid damper. (4) As the settling time is greatly affected by the pocket size, the pocket depth must be made as small as the bearing clearance in order to realize the critical damping condition.