小孔节流静压气体球轴承自激振动现象的研究

Study on Pneumatic Hammer in Externally Pressurized Spherical Gas Bearings with Single Orifice Compensation

分析了单供气孔小孔节流静压气体球轴承在不同供气压力下的动态刚度和阻尼特性,及轴承发生自激振动的频率范围。结果表明,承载质量-气膜系统是一个强非线性的振动系统,系统的动态参数随着扰动频率及工作点的变化而变化。从能量传输的角度看,气膜负阻尼可以理解为气膜非定常力对于承载质量在振动一个周期内作正功,使物体振动加剧,最终产生气锤自激振动。

Dynamic stiffness and damping of externally - pressurized spherical gas - lubricated bearing with single orifice compensation were analyzed in different supply pressure. Vibration frequency of the present gas bearing was confirmed. The mechanism system consist of load mass and gas film is a strong nonlinear vibration system. Parameters of the system will be changed along with variety of operation point and perturbation frequency. From the point of view of energy transmission, negative damping of the gas film can be apprehended that non - stationary force of gas film made positive power to oscillation mass in an oscillation cycle. Amplitude of vibration is augmented and pneumatic hammer is occurred subsequently.