| 摘要 |
A working unit comprises a frame (10) and at least a member (14a) movable along linear directions of movement (U, V, Z) as a result of driving of actuator elements (15a), which is intended to be moved with high accelerations in consequence of which forces and/or moments are applied to the frame (10), which may cause oscillations and vibrations which may affect the precision of workings operations carried out by the working unit (1; 2; 3; 4). The working unit includes members for dynamically balancing the movable member (14a) which comprise, for each direction of movement (U, V, Z) to be balanced of the movable member (14a), at least a counter-weight unit (14b) movable with respect to the frame (10) and second actuator elements (15b) associated to the frame (10) for moving the counter-weight unit (14a) in a mechanically independent manner simultaneously with the movable member (14a) in a direction opposite to its direction of movement, the second actuator elements (15b) being controlled from a same control signal (S) which drives the first actuator elements (14a). The movements of the movable member (14a) and of the counter-weight unit (14b) have, in each moment, the same acceleration, speed and position, and the mass of the counter-weight unit (14b) is equal to the mass of the movable member (14a). |
