VIBRATION ISOLATOR WITH ZERO STIFFNESS WHOSE ANGLE DEGREE OF FREEDOM IS DECOUPLED WITH SPHERICAL AIR BEARING

摘要

A vibration isolator with zero stiffness whose angle degree of freedom is decoupled with a spherical air bearing has a main body, in which a sleeve and a lower mounting plate, a piston cylinder and the sleeve are both lubricated and supported with air bearing surfaces respectively, and the angle degree of freedom between a upper mounting plate and the lower mounting plate is decoupled with a spherical air bearing; a position close-loop control system comprising voice coil motors, displacement sensors, limit switches, a controller and a driver is introduced, and the relative position between the upper mounting plate and the lower mounting plate is precisely controlled.

主权项

1. A vibration isolator with zero stiffness, comprising
a upper mounting plate (1), a lower mounting plate (2), a main body (4) fitted between the upper mounting plate (1) and the lower mounting plate (2), and a clean air compressor (3) connected to the main body (4) through an air pipe (26); wherein the main body (4) comprising a downside-down sleeve (6) lubricated and supported against the lower mounting plate (2) by a planar air bearing surface (21), a upside-down piston cylinder (5) -fitted in the sleeve (6) and lubricated and supported against the sleeve (6) by a cylindrical air bearing surface (22); a spherical air bearing (7) fitted between the piston cylinder (5) and the upper mounting plate (1); a voice coil motor in Z direction (10) for providing a vertical driving force, a displacement sensor in Z direction (13) and a limit switch in Z direction (16) having respective sensitive directions along the direction of the vertical driving force that are fitted between the piston cylinder (5) and the sleeve (6); a voice coil motor in X direction (8) for providing a first horizontal driving force, a displacement sensor in X direction (11) and a limit switch in X direction (14) having respective sensitive directions along the direction of the first horizontal driving force that are fitted between the sleeve cylinder (6) and the lower mounting plate (2); a voice coil motor in V direction (9) for providing a second horizontal driving force perpendicular to the first horizontal driving force, a displacement sensor in Y direction (12) and a limit switch in Y direction (15) having respective sensitive directions along the direction of the second horizontal driving force that are fitted between the sleeve cylinder (6) and the lower mounting plate (2); a controller (19) having signal input terminals connected to the displacement sensor in X direction (11), the displacement sensor in Y direction (12) and the displacement sensor in Z direction (13) as well as the limit switch in X direction (14), the limit switch in Y direction (15) and the limit switch in 2 direction (16) and signal output terminals; a driver (20) having signal input terminals connected to the signal output terminals of the controller (19) and signal output terminals connected to the voice coil motor in X direction (8), the voice coil motor in Y direction (9) and the voice coil motor in Z direction (10) respectively, wherein an air pressure sensor (17) is fitted inside the piston cylinder (5) which is connected to a signal input terminal of the controller (19), a signal output terminal of the controller (19) is connected to a signal input terminal of the driver (20), a signal output terminal of the driver (20) is connected to an electromagnetic valve (18) fitted in the piston cylinder (5).