Ultra-low frequency vibration isolator and design method thereof

Abstract

The invention discloses an ultra-low frequency vibration isolator and a design method thereof. The ultra-low frequency vibration isolator comprises a vibration isolation bearing platen, an upper shell, a lower shell, a bearing rod, a positive rigidity spring and a negative rigidity magnetic spring; and the bearing rod, the upper shell and the lower shell are coaxial, and the vibration isolation bearing platen is arranged on the top end of the bearing rod. The ultra-low frequency isolator and the design method can meet the requirements of the vibration isolator for the bearing capacity and the ultra-low inherent frequency; and meanwhile, the isolator can maintain the linear stiffness characteristic near a working point, so that the restriction to the vibration amplitude and the isolator performance is eliminated, and the excellent low-frequency vibration isolation performance is achieved.

Description

technical field [0001] The invention relates to the field of ultra-low frequency vibration reduction and isolation, in particular to an ultra-low frequency vibration isolator and a design method thereof. Background technique [0002] With the continuous development of a series of ultra-precision processing and measurement technologies represented by ultra-precision grinding, semiconductor processing, micro-nano manufacturing, and surface topography measurement, the processing and measurement accuracy is getting closer and closer to the physical limit. Therefore, the tiny environment Vibration may cause its processing or detection failure. In order to ensure the accuracy of processing and measurement, this type of processing and measuring equipment puts forward extremely high requirements on environmental vibration. Generally speaking, environmental vibration is generally distributed in the low-frequency ultra-low frequency range, and is distributed in a certain frequency ba...

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Problems solved by technology

An invention patent titled "A Parallel Shock Absorber with Positive and Negative Stiffness" (application number CN201310142491.9) proposes a shock absorber based on a parallel connection of a positive stiffness air spring and a negative stiffness magnetic spring. The positive stiffness air spring Arranged in parallel with the negative stiffness magnetic spring, the negative stiffness magnetic spring is installed in the air spring chamber, the problem is that the negative stiffness mechanism is composed of multiple radially magnetized tile-shaped permanent magnets, and the process cost of radially magnetized permanent magnets is high and difficult Large, while the negative stiffness magnetic spring is composed of a large number of permanent magnets, so the processing is complicated and the assembly cost is extremely high

However, when the excitation amplitude (larger amplitude) becomes larger, the stiffness characteristics of the vibration isolator will show strong nonlinear characteristics, making the vibration isolator appear nonlinear resonances such as superharmonic resonance, subharmonic resonance, and quasi-period resonance, thus As a result, the performance of the vibration isolator deteriorates rapidly, obviously its application is greatly restricted

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