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NEW METHOD OF DYNAMIC
TEST FOR
STATIC STIFFNESS OF
EXTERNALLY
PRESSURIZED GAS BEARING
GUO Liangbin1 WANG Zuwen2
(1. College of Urban Construction, Wuhan University of Science and Technology, Wuhan 430070;
2．Electromechanics and Materials Engineering
College, Dalian Maritime University, Dalian 116026
)
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Abstract:
By instancing externally pressurized spherical gas bearing with
inherently compensation, equivalent mathematical model of static
stiffness, dynamic stiffness and frequency response function of
aerostatic bearing are built. In the presence of mathematic analysis
and numerical experiment, the relation between static stiffness,
dynamic stiffness and frequency response function is opened out
theoretically. It is indicated that static stiffness in externally
pressurized gas bearing at operating point can be acquired by
measure amplitude frequency response characteristics of gas film in
low frequency. Operating principle of the test apparatus for
spherical gas bearing and influence of apparatus’ mechanical modal
to test results are introduced. The results show that the new method
of static stiffness measurement adopted dynamic test technique is correct and feasible. For inherent nonlinear vibration system consist of gas film and loading mass, dynamic stiffness in low frequency is equal to the static stiffness of the bearing at the operating point. On-line automatic testing of bearing static stiffness can be achieved by the new method and testing accuracy and efficiency is increased. After expansion of excitation frequency to the frequency range involved by mechanical system, static stiffness, dynamic stiff-ness and amplitude frequency response characteristics of externally pressurized gas bearing can be obtained at the same time by the new method. It is highly important to the study of stability and dynamic property of aerostatic bearing and precise shafting, which can be never implemented only by the static testing method of bearing’s stiffness.
Key words: Externally pressurized gas bearing
Static stiffness Dynamic stiffness
Amplitude frequency response characteristics
CLC No: TH133.36
国家自然科学基金(50335010)和武汉科技大学科学研究发展基金(2005XZ2)资助项目. Received 20060512, received in revised form 20061211
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