Zero-rigidity vibration isolator with double-layer air flotation orthogonal decoupling and rolling knuckle bearing angular decoupling

Abstract

The invention belongs to the technical field of precise vibration isolation and discloses a zero-rigidity vibration isolator with double-layer air flotation orthogonal decoupling and rolling knuckle bearing angular decoupling. A sleeve of a vibration isolator and an air flotation plate, the air flotation plate and a lower mounting plate, and a piston barrel and a sleeve are lubricated and supported through air flotation faces, the freedom degree of horizontal linear motion between an upper mounting plate and the lower mounting plate is decoupled through a double-layer orthogonal air flotation guide rail, the freedom degree of angular motion between the upper mounting plate and the lower mounting plate is decoupled through a rolling knuckle bearing, and a voice coil motor, a displacement sensor, a limiting switch, a controller and a drive form a position closed-loop feedback control system to precisely control relative positions of the upper mounting plate and the lower mounting plate. The zero-rigidity vibration isolator has the advantages of three-dimensional zero rigidity, high positioning precision, decoupling of linear motion freedom degree and angular motion freedom degree, and high-performance vibration isolation in ultra precise measurement instruments and processing equipment, especially in step scanning photoetching machines can be effectively achieved.

Description

technical field [0001] The invention belongs to the technical field of precision vibration isolation, and mainly relates to a zero-stiffness vibration isolator for double-layer air bearing orthogonal decoupling and rolling joint bearing angle decoupling. Background technique [0002] With the continuous improvement of ultra-precision machining and measurement accuracy, environmental vibration has become an important factor restricting the improvement of the accuracy and performance of ultra-precision machining equipment and measuring instruments. In particular, the ultra-large-scale integrated circuit processing equipment represented by the step-scan lithography machine is extremely technically intensive and complex, and the key technical indicators have reached the limit of the existing technology, representing the highest level of ultra-precision processing equipment. Precision vibration isolation has become the core key technology in this type of equipment; the line width...

AI Technical Summary

Problems solved by technology

The problems of this method are as follows: 1) Due to the constraints of material properties and structural stiffness, the amplitude of vertical and horizontal stiffness reduction of the vibration isolator is limited; 2) The vertical and horizontal positioning accuracy of the air spring vibration isolator is very poor, It cannot meet the requirements of the photolithography process; 3) To achieve a lower horizontal stiffness requires a larger pendulum length, resulting in excessive height of the vibration isolator, prone to string-film resonance, and poor stability

The problems of this solution are: 1) In the disclosed technical solution, the vibration isolator cannot achieve precise positioning; 2) In the patent EP1803965A2, there is no degree of freedom of angular movement around the horizontal axis between the upper and lower mounting plates. The angular stiffness and natural frequency are very high; patents EP1803970A2 and US20080193061A1 use rubber blocks to provide angular freedom of rotation around the horizontal axis for the upper and lower mounting plates, but due to the high angular stiffness of the rubber blocks, the angular freedom of motion cannot be effectively achieved Degree decoupling, the friction between the decoupling mechanism components of the angular motion freedom introduces additional stiffness, which restricts the vibration isolation performance

However, the proposed technical solution still does not solve the problem of decoupling the precise positioning of the vibration isolator and the angular motion freedom of the upper and lower mounting plates.

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