Double-layer orthogonal air floatation decoupling and sliding knuckle bearing angular decoupling magnetic levitation vibration isolator

Abstract

The invention belongs to the technical field of precision vibration isolation and relates to a double-layer orthogonal air floatation decoupling and sliding knuckle bearing angular decoupling magnetic levitation vibration isolator. A magnetic levitation thrust bearing is used for bearing between a sleeve of a vibration isolator body and an air floatation plate, air floatation surfaces are used for lubricating and supporting between the air floatation plate and a lower mounting plate as well as between a piston cylinder and the sleeve, degree of freedom of horizontal linear motion between an upper mounting plate and the lower mounting plate is decoupled by double-layer orthogonal air floatation guide rails, degree of freedom of angular motion between the upper mounting plate and the lower mounting plate is decoupled by a sliding knuckle bearing, and voice coil motors, displacement sensors, limit switches, a controller and a drive form a position closed-loop feedback control system so as to precisely control the relative position of the upper mounting plate and the lower mounting plate. The magnetic levitation vibration isolator has the advantages of zero three-dimensional rigidity, high positioning precision and decoupling of degree of freedom of linear motion and degree of freedom of angular motion, and is capable of effectively achieving high-performance vibration isolation of ultra-precise measuring instruments and processing equipment, particularly in step-scan lithography machines.

Description

technical field [0001] The invention belongs to the technical field of precision vibration isolation, and mainly relates to a magnetic suspension vibration isolator with double-layer air bearing orthogonal decoupling and sliding 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...

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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