Abstract: An electromechanical valve actuator for internal combustion engines is equipped with a polarized electromagnet exerting a magnetic action on a magnetic plate that is subject to a mechanical restoring action, which action can compensate for the mechanical action and maintain the plate in a distant position from the electromagnet. The actuator ensures that the displacements of the plate are controlled solely by this electromagnet and the mechanical restoring action such that the plate performs shuttle movements beginning from the distant position.

Abstract: An electromagnetic valve actuator for internal combustion engines, includes an electromagnet and a mobile magnetic plate intended to come into contact with a part of the electromagnet. At least one stop is located on the electromagnet or on the plate to limit the contact surface between the plate and the electromagnet. The actuator i the electromagnet includes a magnet in its magnetic circuit.

Abstract: A magnetic bearing for centering and controlling tilting of a first body relative to a second body includes centering members adapted to center the first body magnetically relative to the second body at least in the direction transverse to the reference axis, two permanently magnetized rings carried by a first ferromagnetic armature fastened to the first body, an annular plurality of (at least three) tilt windings fastened to the second body and each including two groups of circumferential strands respectively adapted to face each of the permanently magnetized rings regardless of the orientation of the hollow outer part, and an excitation circuit adapted to apply excitation currents to the tilt windings adapted to generate tilting forces in the air-gaps.

Abstract: A magnetic bearing for centering a first body, which is mobile in tilting, relative to a second body includes: a hollow outer part at least part of which is made from a ferromagnetic material and which is attached to the first body and which has an inside surface whose shape is a portion of a sphere, an inner part which is attached to the second body and which includes two separate members which are separated by a space and which each include a plurality of (at least three) ferromagnetic areas which are offset angularly about the reference axis, which each define in conjunction with the inside surface of the hollow outer part two air-gaps offset relative to the reference axis and which are each provided with a specific winding adapted to generate magnetic flux lines closing across the two air-gaps, and an excitation circuit for selectively applying excitation currents to the windings.

Abstract: The present invention relates to a system for driving two mechanical members in rotation about an axis by magnetic coupling of the attractive type, the system comprises respective magnetic elements secured to each of said mechanical members, the two magnetic elements being concentric, one of them being made up of two identical magnetic rings of minimum radius R.sub.3 and of maximum radius R.sub.4, and the other one of them being made up of a magnetic ring having a minimum radius R.sub.1 and a maximum radius R.sub.2, with its midplane perpendicular to the axis of rotation being offset by a distance d from the midplanes of each of said two identical rings. Each ring possesses magnetization in a direction contained in a plane that is perpendicular to the axis of rotation. Each ring also possesses N magnetic poles uniformly distributed around said axis of rotation. The ratio 2d/.vertline.(R.sub.3 +R.sub.4)-(R.sub.1 +R.sub.2).vertline. lies in the range 0.2 to 0.8.

Abstract: The bearing has a fixed portion, and a moving portion, and includes a passive magnetic abutment composed of a fixed element secured to said fixed portion, and of a moving element secured to said moving portion. The bearing further including a passive magnetic centering bearing which is coaxial with said passive abutment, and which is composed of a fixed element secured to the fixed portion, and of a moving element secured to the moving portion, the passive abutment externally surrounding the passive centering bearing, the passive abutment having axial stiffness k.sub.ab, radial stiffness k.sub.rb, a mean radius R.sub.mb, and an inside radius R.sub.ib, and said passive centering bearing having axial stiffness k.sub.ac, radial stiffness k.sub.rc, a mean radius R.sub.mc, and an outside radius R.sub.

Abstract: A vibration damper device (1) intended to be mounted on a sports article such as, in particular, a tennis or squash racket, a gliding board or a golf club, whereinthe device includes at least two elements (3, 4) superposed to form a stack and mounted so as to slide relative to one another, each element (3, 4) in said stack being secured to the article by one end, the ends (13, 14) of the adjacent elements being offset relative to one another so that the deformations of the article (8) due to the vibrations cause the adjacent elements (3, 4) to slideand at least one of the superposed elements (4) is magnetized, one of the other elements (3) in the stack being made of a material which is sensitive to the magnetic field generated by the magnetized element (4).

Abstract: A rotary assembly comprising a stator and a rotor of axis .DELTA., rotary drive means, radial support means, and an active magnetic axial abutment comprising a magnetic circuit in two portions, namely a fixed portion, and a moving portion, the two portions being separated from each other by two parallel plane air gaps, each portion of said magnetic circuit being circularly symmetrical about axis .DELTA., and having the shape of an open channel-section extending about said axis .DELTA., the open ends of the two portions of magnetic circuit facing each other, an electrical coil being received in the inside annular space of the fixed portion of the magnetic circuit, wherein a drive winding secured to said axial abutment coil and received in the inside annular space of the moving portion of said magnetic circuit co-operates with permanent magnets fixed to the moving portion of said magnetic circuit, and facing said drive winding.