Abstract: A vibrator acting in a low frequency vibration domain, for fixing to and applying low frequency vibrations on a frame in a first predetermined direction along an axis X'X.

Abstract: The auxiliary bearing comprises a chromium steel rotor (2) mounted on the rotary shaft (1), a graphite stator (3) mounted on the frame (5) and disposed to face the rotor (2) and to leave clearance relative thereto which is narrower than the air gap in the magnetic bearings which constitute the main supports of the rotary shaft, a network (4) of liquid feed channels opening out into the empty space between the rotor (2) and the stator (3), and selective control means for controlling the supply of liquid through said network of feed channels. The auxiliary bearing may be of the radial clearance type or of the axial clearance type.

Abstract: A combination vibration generator and dampener having magnetic suspension and servo-control along three axes includes a hollow outer body fixed to a structure whose vibration is to be controlled, and an inner body which is essentially spherical in shape and which is inside the hollow outer body. Six active magnetic bearing elements are diametrically disposed in pairs along three orthogonal axes and serve to hold the inner spherical body inside the hollow outer body without direct contact between the inner and outer body. At least three position detectors detect the position of the inner body relative to the hollow outer body while at least one vibration detector device detects vibration forces on the structure whose vibration is to be controlled.