Two-degree-of-freedom ultralow-frequency vibration isolator

Abstract

The invention discloses a two-degree-of-freedom ultralow-frequency vibration isolator. The two-degree-of-freedom ultralow-frequency vibration isolator comprises a basic platform (10) and a load-bearing platform (30), and the basic platform (10) and the load-bearing platform (30) are connected through supporting rods. The two-degree-of-freedom ultralow-frequency vibration isolator is characterized in that the vibration isolator further comprises a positive-stiffness air spring (20) and a magnetic negative-stiffness mechanism (28) with adjustable negative stiffness, and the positive-stiffness air spring (20) and the magnetic negative-stiffness mechanism (28) form a parallel mechanism in the direction of the center axes of the basic platform and the load-bearing platform, so that the inherent frequency in the direction of the center axes of the basic platform and the load-bearing platform is decreased; and a stiffness-adjustable positive-stiffness leaf spring and a negative-stiffness inverted pendulum are arranged in the direction perpendicular to the center axes of the basic platform and the load-bearing platform and form a negative-stiffness parallel mechanism, so that the inherent frequency in the direction perpendicular to the center axes of the basic platform and the load-bearing platform is decreased. According to the vibration isolator, positive-stiffness and negative-stiffness parallel type passive structures are adopted both in the direction of the center axes of the basic platform and the load-bearing platform and in the direction perpendicular to the center axes of the basic platform and the load-bearing platform, and thus vibration of two degrees of freedom is achieved at the same time.

Description

technical field [0001] The invention belongs to the field of ultra-precision vibration reduction, in particular to a two-degree-of-freedom ultra-low frequency vibration isolator. Background technique [0002] Micro-vibration isolation technology is widely used in precision vibration-sensitive equipment such as semiconductor processing and measuring instruments to suppress disturbances from foundations and external excitations. With the continuous improvement of the precision of ultra-precision equipment, the requirements for the performance index of the vibration isolation system are becoming more and more stringent. In the field of large-load precision machining, the parallel connection of positive and negative stiffness mechanisms can achieve a large load-bearing capacity of the vibration isolation system while having an extremely low system natural frequency, thereby improving the ultra-low frequency vibration reduction capability of this type of vibration isolator. [0...

AI Technical Summary

Problems solved by technology

[0004] The air spring has the characteristics of low stiffness and large bearing capacity, and is widely used in large-load precision vibration isolation systems. Because its stiffness is inversely proportional to the volume of the chamber, when the design natural frequency is low, the volume of the air spring chamber will be too large and The position control is unstable, which makes it unable to work normally, so the air spring cannot meet the requirements of ultra-low frequency vibration isolation

The positive and negative stiffness mechanisms used in traditional vibration isolation devices can only provide stiffness characteristics in one direction to achieve a single-degree-of-freedom vibration isolation effect. To achieve multi-degree-of-freedom vibration isolation, each degree of freedom must be set corresponding The positive and negative stiffness of the parallel device will increase the complexity of the device

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