METHOD OF VIBRATION ISOLATION AND DESIGN OF VIBRATION ISOLATOR Russian patent published in 1997 - IPC

FIELD: mechanical engineering; vibration isolating devices. SUBSTANCE: vibration isolated object (not shown in Drawing) is placed on platform coupled with base 2 by means of suspension in form of articulated lever mechanisms 3. Suspension has six degrees of freedom. It is made in form of six independent articulated lever mechanisms, upper part of each is connected with platform through resilient member 4 being high-frequency filter. Vibration isolators are installed so that projections of four articulated lever mechanisms on horizontal plane lie on sides of square inscribed in horizontal projection of platform 1. Projection of fifth articulated lever mechanism lies on diagonal of square, and projection of sixth mechanism, is square to diagonal and is enclosed in square. Device for implementing the proposed method of vibration isolation operates as follows. Accelerometers 11 and 12 measure vibration acceleration of clamp 6 and base 2 on line connecting centers of Hooke's joints, and relative displacement pickup 14 records their relative displacement. Feedback control (main control algorithm) is provided by pickups 11 and 14, and additional control signal is superimposed on main control from pickup 12. This control signal is called invariant signal. It makes acceleration measured by pickup 11 equal to zero, i. e. platform 1 becomes as if stationary in inertia space (this is true only for area of low frequencies passed by servodrive in form of motor with worm drive). If larger accelerations are detected on base 2, relative position of two clamps may come out of tolerable displacement limits (system may come to rigid stops). To prevent such situation when displacement reaches maximum tolerable value, other control algorithm is engaged. Signal from accelerometer 12 is switched off, and system is controlled by feedbacks from acceleration pickup 11 and relative displacement pickup 14 until relative displacement becomes smaller than above indicated tolerable value after which main control algorithm is engaged. EFFECT: improved vibration isolation. 3 cl, 4 dwg