Moving Magnet Technologies (mmt)

Moving Magnet Technologies

Mmt Sa

Stéphane Biwersi

Pierre Gandel

Guillaume Loussert

Gérald Masson

Michaël Delbaere

Javier Rios-Quesada

Gaël Andrieux

Didier Frachon

Arnaud Hyppias

Yannick Ronnat

Stéphane Tavernier

Lionel Billet

Michael Delbaere

Michaél Delbaere

Mathieu Aubertin

An actuator for controlling the movement of an element between two stable positions with pulsed electrical control without a change in polarity comprises: a ferromagnetic mobile mass, at least one electrically controlled wire coil that is fixed with respect to the mobile mass, at least two ferromagnetic poles that are fixed with respect to the mobile mass and on either side of the mobile mass. The actuator comprises at least one permanent magnet that attracts the mobile mass in order to achieve the two stable positions. The mobile mass defines, with the ferromagnetic poles, at least two variable air gaps during the movement of the mobile apparatus. The magnetic flux of the permanent magnet opposes the magnetic flux generated by the at least one coil regardless of the position of the mobile mass.

Ballistic unipolar bistable actuator

A rotary actuator with a moving frame includes an electrical coil that moves on an angular travel about an axis of rotation A, the shape of the coil being an elliptical cylinder and the axis of winding B being orthogonal to the axis of rotation A, the coil being placed in the magnetic field of a fixed magnet. The fixed magnet surrounds the coil and includes two semicylindrical portions, the generatrices of which are orthogonal to the axis of rotation A, the first of the semicylindrical portions having a north pole directed toward the coil, orthogonally to the direction of the generatrices and being positioned outside the coil, the second having a south pole directed toward the coil, orthogonally to the direction of the generatrices and also being positioned outside the coil opposite the first portion. The actuator includes a ferromagnetic core inside the coil and an outer ferromagnetic yoke surrounding the fixed magnet, the coil moving in the air gap formed between the magnetized semicylindrical portions and the inner core.

Actuator with moving coil frame and enhanced dynamics

A linear electromagnetic actuator has a stroke c, with at least one stable position in one of the ends of the stroke, and includes: an armature made of a soft magnetic material, the armature being movable in an axial direction Y and having a length Hm in the direction Y, the armature having a symmetrical shape at the axis Y, and a stationary stator yoke made of a soft magnetic material and holding at least one electric coil. The actuator also includes at least one stationary permanent magnet that is magnetized along a transverse axis X perpendicular to the direction Y. The magnet is transversely placed between the movable armature and the electric coil. The magnet has a length Ha in the direction Y. The stationary yoke and the movable armature define therebetween at least one axial air gap. Ha+c is of the order of magnitude of Hm. The length Hm is such that 0.9&#xd7;(Ha+c)&#x3c;Hm&#x3c;1.1&#xd7;(Ha+c) so that, when the movable armature is in the end stability position thereof, one of the two axial ends of the movable armature is adjacent to one of the two axial ends of the permanent magnet.

Linear actuator with improved magnetic stability and stripping force

A linear electromagnetic actuator includes a stator excited by at least one electric coil arranged around an axis of symmetry and two ferromagnetic stator poles positioned axially on either side of the coil, as well as at least two independent moving members, each of the moving members being formed of a ferromagnetic material, where the linear electromagnetic actuator includes at least three magnetized poles arranged inside the coil, with respectively a first magnetized pole positioned in the vicinity of the median plane separating the two moving members and containing the axis of the coil, and a second and third magnetized pole arranged laterally on either side of the moving members, between the moving members and the coil.

Linear electromagnetic actuator comprising two independent moving members

The present disclosure relates to a mono- or polyphase electric motor including a stator carrying at least three coils and consisting of 12&#xd7;N straight teeth extending radially, N being an integer greater than or equal to 1, and of an equal peak divergence alpha, measured at their end from the center of the motor, and a rotor exhibiting P pairs of magnetized poles such that P=5+2&#xd7;R, P being a non-multiple of three, R being an integer greater than or equal to 0, alpha lying between 360&#xb0;(12&#xd7;N)/3 and 360&#xb0;(12&#xd7;N)/2.

Optimized electric motor with narrow teeth

An electrical machine includes a tubular rotor magnetised to have circumferential polar alternations, and a stator including a body that is traversed by a channel having an inner transverse section that substantially corresponds to the outer transverse section of the rotor, the body carrying a plurality of windings, the stator being surrounded by an outer ferromagnetic envelope, the body being extended by three, four or six radial projections made from an electrically insulating material having, in the transverse cross section, a longitudinal core for receiving a winding, the core being extended by a peripheral extension having an outer surface that matches the inner surface of the envelope and covers the wound area. A method for producing such an electrical machine is also provided.

Slotless electrical machine with concentrated winding

The present disclosure relates to a position-indicating module including a position sensor consisting of a mobile element, able to be driven directly by an operator or by a mechanical or electromechanical drive element, and of a detection assembly delivering electrical information dependent on the position of the mobile assembly, as well as at least one illumination element including at least one light source, wherein the mobile assembly includes a zone able to allow through the light beam issuing from the illumination element and the illumination element is situated opposite the zone.

Position-indicating module with illuminated axis

The disclosure relates to a magnetic device for detecting the absolute position of an input shaft capable of rotating more than 360&#xb0;, the device including a main magnetic sensor, a motion reducer, and a secondary magnetic sensor, wherein the main magnetic sensor is connected to a rotor, measures the rotation of the shaft for ranges of angles of less than 360&#xb0;, and includes a main magnet, the motion reducer converts the rotation of the shaft into a reduced rotation, the maximum amplitude of which is equal to no more than 360&#xb0;, and the secondary magnetic sensor measures the reduced rotation and includes a secondary magnet. According to the disclosure, the secondary magnet is arranged between the upper and lower planes of the main rotor, and the main magnet has P pairs of poles, where P is greater than 1.

Magnetic multi-turn absolute position detection device

The present disclosure relates to a magnetic position sensor with field direction measurement and a flux collector. The disclosure proposes to measure two magnetic induction components at one and the same point, harmonizing the amplitude of the two magnetic induction components using flux collectors so as to have a ratio of the amplitudes of these two components close to one. For this purpose, the disclosure provides a contactless position sensor including at least one permanent magnet, emitting a magnetic field, at least one detection element sensitive to the direction of the magnetic field, and at least one pair of flux collectors, the permanent magnet being capable of moving in a direction of displacement and having a direction of magnetization that can be continuously varied according to the direction of displacement. Each flux collector has at least one portion, provided with an end, extending substantially along the direction of displacement of the magnet. The ends of a pair of flux collectors define a gap oriented along the direction of displacement of the magnet. The detection element is positioned outside the gap and substantially equidistant from the ends.

Magnetic position sensor with field direction measurement and flux collector

The disclosure relates to a magnetic position sensor including at least one permanent magnet. The disclosure also relates to a magnetic device for detecting a torque between a first shaft and a second shaft that are connected via a torsion bar. The aim of the disclosure is to provide a device for determining the multi-periodic absolute position of a magnetized unit. The subject of the disclosure is therefore a magnetic position sensor including at least the following: a magnetized unit, a first magnetosensitive probe and a second magnetosensitive probe. The second magnetosensitive probe is capable of measuring a number of complete rotations of the magnetic field in an absolute, incremental and reversible manner so as to determine a second datum relating to the position of the magnet, whether or not this second magnetosensitive probe is powered. The sensor further includes a module for calculating the absolute position of the magnet on the basis of the first and second data coming from the first and second probes respectively.

Growing community of inventors

Frambouhans, France

Stéphane Biwersi