Abstract: The invention relates to a position sensor which is intended, in particular, for detecting a steering column torsion. The invention consists of: a first magnetic rotor structure (10) comprising a plurality of radially-oriented magnets; a second stator structure comprising two rings (23, 24) which extend into axially-oriented overlapping teeth (25, 26); and a third fixed collector structure (30) comprising two flux-closing parts which define at least one air gap in which at least one magneto-sensitive element is placed. The invention is characterized in that the flux-closing parts and the stator rings (23, 24) define therebetween a constant collection surface that is independent of the relative radial position of the two structures.

Abstract: A linear actuator includes a brushless polyphase synchronous electric motor having a stator and a rotor. The rotor acts on a control element via a driver which can transform the rotation movement thereof into a linear movement over several rotations. Preferably, the inventive actuator comprises elastic and/or magnetic return device which can systematically return the control element to a reference position when the power supply to the motor is cut. The motor has a position detection device which, together with an electronic control unit, is used for the automatic control and regulation of the position of the rotor and, therefore, the control element.

Abstract: A polyphase motor, for example for applications for driving pumps or ventilators in the automobile industry, including a stator part excited by electric coils and a rotor exhibiting N pairs of poles that are magnetized radially in alternate senses, the stator part exhibiting wide teeth and narrow teeth extending radially from an annular ring. The wide teeth carry the coil windings and the distance between a wide tooth and a narrow tooth is greater than the width of a narrow tooth.

Abstract: A position sensor, which can detect a steering column twist of a first magnetic rotoric structure including a plurality of radially oriented magnets and a second statoric structure including two concentric gear rings extended by radially oriented teeth. The rotoric structure is substantially disc-shaped and includes a ferromagnetic head supporting the plurality of magnets, the statoric structures are provided with interleaving teeth and the position sensor includes a third collector structure including two flow closing parts, one of which is fixed, and which define at least one air gap in which at least one magnetosensitive element is arranged.

Abstract: The invention relates to an electromagnetic actuator comprised of a mobile assembly, a fixed ferromagnetic stator assembly, at least one electric field coil, and of at least one permanent magnet, having two stable positions of equilibrium without current at its ends of travel. The invention is characterized in that the mobile assembly has two distinct ferromagnetic armatures placed on both sides of the stator assembly and each forms, together with the stator assembly, at least one magnetic circuit, and is characterized in that the permanent magnet magnetically cooperates with one of the other ferromagnetic mobile parts in a stable position of equilibrium without current at the end of travel.

Abstract: The invention relates to a position sensor which is intended, in particular, for detecting a steering column torsion. The invention consists of: a first magnetic rotor structure (10) comprising a plurality of radially-oriented magnets; a second stator structure comprising two rings (23, 24) which extend into axially-oriented overlapping teeth (25, 26); and a third fixed collector structure (30) comprising two flux-closing parts which define at least one air gap in which at least one magneto-sensitive element is placed. The invention is characterized in that the flux-closing parts and the stator rings (23, 24) define therebetween a constant collection surface that is independent of the relative radial position of the two structures.

Abstract: A stop-detection method intended for a multi-phase synchronous geared motor that is controlled in a stepping mode, which measures the sum of the currents circulating in each of the N phases of the geared motor. In the method the stop detection threshold is calculated in relation to the change in the sum of the currents.

Abstract: An electric actuator including at least a first P-phase automatically-switched brushless synchronous motor, P being an integer ranging between 1 and 6, and N pairs of poles at the rotor, N being an integer not less than 1. The actuator also includes a position sensor outputting signal to control an electronic circuit controlling the motor. The rotor of the motor drives a gear ratio reducing mechanism. The position sensor is coupled to the reduction unit output shaft to measure the absolute angular position of the reduction unit output shaft. The electronic circuit includes a circuit sequentially controlling the current of each of the phases producing automatic switching of powering sequences of the phases on the basis of the absolute position of the reduction unit output shaft.

Abstract: A stop-detection method intended for a multi-phase synchronous geared motor that is controlled in a stepping mode, which measures the sum of the currents circulating in each of the N phases of the geared motor. In the method the stop detection threshold is calculated in relation to the change in the sum of the currents.

Abstract: A position sensor, designed in particular for detecting a steering column torsion, including a first magnetic structure including a plurality of magnets and a second magnetic structure including two ferromagnetic rings having a plurality of teeth and defining an air gap. At least a magneto-sensitive element is placed in the air gap. The first and second magnetic structures are respectively integral with two parts in relative rotation. The two ferromagnetic rings are nested and have each a substantially tubular part forming axially oriented teeth connected by a flux-closing zone, the detecting air gap being delimited by the flux-closing zones.

Abstract: The invention concerns a position sensor, designed in particular for detecting a steering column torsion, consisting of a first magnetic structure including a plurality of magnets and a second magnetic structure including two ferromagnetic rings (6, 7) having a plurality of teeth (11, 12) and defining an air gap wherein is placed at least a magneto-sensitive element (15), the two magnetic structures being respectively integral with two parts in relative rotation. The invention is characterised in that the two ferromagnetic rings (6, 7) are nested and have each a substantially tubular part forming axially oriented teeth (11, 123) connected by a flux-closing zone (13, 14), the detecting air gap being delimited by said flux-closing zones.

Abstract: A linear actuator includes a brushless polyphase synchronous electric motor having a stator and a rotor. The rotor acts on a control element via a driver which can transform the rotation movement thereof into a linear movement over several rotations. Preferably, the inventive actuator comprises elastic and/or magnetic return device which can systematically return the control element to a reference position when the power supply to the motor is cut. The motor has a position detection device which, together with an electronic control unit, is used for the automatic control and regulation of the position of the rotor and, therefore, the control element.

Abstract: A position sensor including at least one stator structure defining a secondary gap wherein is housed at least one Hall probe, and a mobile magnet in a main gap. The stator structure includes stator parts defining at least one first secondary gap wherein is housed at least one first Hall probe delivering a signal which is a function of the displacement of the mobile magnet relative to a first degree of freedom, and at least one second secondary gap wherein is housed at least one second Hall probe delivering a signal which is a function of the displacement of the mobile magnet relative to a second degree of freedom.

Abstract: A a rotating electromagnetic actuator with limited stroke, including at least 2N poles on the stator, N being a whole number, energized by at least one energizer coil and N magnetized parts on the rotor arranged in an air gap of thickness E wherein each magnetized part is juxtaposed with at least one ferromagnetic part with a thickness e between 0 and E, defining one or two air gaps with a total length of E-e.

Abstract: A linear uniphase polarized electromagnetic actuator. The actuator includes a coiled stator and one part which is movable in the direction OX with the useful travel of Xc. The movable part is moved according to the current traveling in the coil and the direction of travel depends on the direction of the current. The movable part includes a yoke of soft magnetic material having at least one magnet coupled with the yoke. The magnet is partially set inside a cavity of the mobile yoke on the side of the stator poles at a depth e such that 0.1 L<e<0.9 L, where E is the distance measured perpendicularly to OX between the stator poles and the cavity end pole.

Abstract: This invention pertains to an incremental sensor of position and/or speed, of the type which includes a moving component made of a soft material that has at least one moving tooth in a direction OZ with respect to a permanent magnet magnetized along the direction OY, which is approximately perpendicular to the OZ axis, and a probe which is sensitive to the direction and strength of the magnetic field, such as a Hall-effect gaussmeter, arranged in the air gap between the magnet and the tooth of the moving component so that its axis of greatest sensitivity is approximately oriented along the OZ axis. The Hall-effect gaussmeter is located near a singular point of the OZ axis where the average value of the magnetic field is weak and preferably less than .+-.20 mT and approximately equal to the average value of the alternating field of the integrated circuit connected to the Hall-effect gaussmeter. The permanent magnet can also be laser trimmed to achieve the desired operation in the Hall-effect gaussmeter.

Abstract: A monophase electromagnetic actuator including at least a ferromagnetic part integral with a member movable along a direction Y, a fixed stator part made of soft magnetic material and including at least on electrical coil, and a thin transversely magnetized permanent magnet. The fixed stator part and the ferromagnetic part define between each other at least two air gaps arranged symmetrically with respect to the medial plane perpendicular to the axis of displacement of the movable member and passing through the middle of the permanent magnet. The length of the ferromagnetic part is approximately equal to the length of the permanent magnet.

Abstract: This invention pertains to an incremental sensor of position and/or speed, of the type which includes a moving component made of a soft material that has at least one moving tooth in a direction OZ with respect to a permanent magnet magnetized along the direction OY, which is approximately perpendicular to the OZ axis, and a probe which is sensitive to the direction and strength of the magnetic field, such as a Hall-effect gaussmeter, arranged in the air gap between the magnet and the tooth of the moving component so that its axis of greatest sensitivity is approximately oriented along the OZ axis. The Hall-effect gaussmeter is located near a singular point of the OZ axis where the average value of the magnetic field is weak and preferably less than .+-.20 mT and approximately equal to the average value of the alternating field of the integrated circuit connected to the Hall-effect gaussmeter.

Abstract: The present invention relates to an electromagnetic actuator comprised of a stator structure made of soft magnetic material which is unsaturated in rated operating conditions, comprising two stator parts (1 and 2) at least one of the stator structures (1) presenting a central pole (5) having a length Y.sub.C and two side poles (6,7) having a length Y.sub.L said stator parts (1,2) delimiting an air gap E inside which there is arranged a rotor movable member comprising two pairs of poles having a length Y.sub.R comprised of thin permanent magnets (10 and 11) which are transversely magnetized, characterized in that the length Y.sub.C of the central stator pole (5) is longer or equal to the stroke Y of the rotor movable member increased by a length substantially equal to the length E of the air gap, the length Y.sub.

Abstract: A position sensor which includes a stator presenting a slot forming a main air-gap inside which is positioned a permanent magnet, and including a sensor which features a magnetism-sensitive probe for measuring magnetic flow formed in a secondary air-gap. The permanent magnet is of a bipolar type and is movable inside the main thin air-gap delimited by ferromagnetic parts joined by non-magnetic connecting parts. The length of the main air-gap as measured along the direction of displacement of the movable magnet is at least 2(C+E), C designating the travel of the magnet and E designating the width of the main air-gap, the length of the magnet further being at least equal to (C+E) and its travel being at least .+-.C/2 with respect to the secondary air-gap perpendicular to the main air-gap.