Patents Assigned to Moving Magnet Technologies
  • Patent number: 8963541
    Abstract: The invention relates to a contactless magnetic sensor for detecting a linear or angular position, comprising a moveable ferromagnetic element (1) the position of which is detected, and a stator assembly (2) itself, comprising two ferromagnetic parts (3, 4), defining with the moveable ferromagnetic element (1) two respective air gaps (7, 8), a permanent magnet (5) and a magneto-sensitive element (6) subjected to a magnetic field that depends on the position of the moveable ferromagnetic element (1) and designed to deliver a measurement signal that depends on the magnetic field to which it is subjected. According to the invention, the two ferromagnetic parts (3, 4) define therebetween a third air gap (9), the permanent magnet (5) being rigidly connected only to the first ferromagnetic part (3) and the magneto-sensitive element (6) being placed in the third air gap (9).
    Type: Grant
    Filed: April 7, 2011
    Date of Patent: February 24, 2015
    Assignee: Moving Magnet Technologies (MMT)
    Inventors: Didier Frachon, Stephane Biwersi
  • Patent number: 8890514
    Abstract: 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.
    Type: Grant
    Filed: July 7, 2010
    Date of Patent: November 18, 2014
    Assignee: Moving Magnet Technologies (MMT)
    Inventors: Gérald Masson, Stéphane Biwersi
  • Patent number: 8860282
    Abstract: The invention concerns a polyphase motor comprising M phases, M being equal to 2 or 3, the motor consisting of a stator part (1) excited by electric coils and by a magnetized rotor (2). The invention is characterized in that the rotor (2) has a disc-shaped magnetized part with R pairs of alternately poles magnetized in alternating directions in the thickness, R being equal to n*(M+1) or 5*n, and said stator part (1) has S poles, some of which excited at least by an electric coil, S being equal to 8*n, for even M, and 9*n for odd M, n being an integer not less than 1.
    Type: Grant
    Filed: September 25, 2002
    Date of Patent: October 14, 2014
    Assignee: Moving Magnet Technologies
    Inventors: Pierre Gandel, Daniel Prudham
  • Patent number: 8587294
    Abstract: The invention relates to an angular or linear magnetic position sensor that comprises a mobile member including at least one magnet (1) having a magnetization direction that varies linearly along the movement direction of the magnet in a surface defined by said movement direction and in a normal direction, at least four magneto-sensitive elements (2, 3 and 4, 5) and at least one processing circuit (6) providing a signal based on the absolute position of the mobile member, characterized in that a first set of magneto-sensitive elements (2, 3) and (4, 5) are located at a same point, the first couple of magneto-sensitive elements (2, 3) being spatially offset from a second couple of magneto-sensitive elements (4, 5) along the movement direction, and in that the magneto-sensitive elements (3 and 5) measure the tangential component of the magnetic field while the magneto-sensitive elements (2 and 4) measure the normal component of the magnetic field in order to provide, after algebraic combination of the component
    Type: Grant
    Filed: November 20, 2008
    Date of Patent: November 19, 2013
    Assignee: Moving Magnet Technologies (MMT)
    Inventors: Gérald Masson, Nikola Jerance, Didier Frachon, Richard Arlot, Thierry Dorge
  • Patent number: 8373410
    Abstract: The invention relates to a magnetic angular or linear sensor including at least one permanent magnet defined in a cylindrical (r, Q & z) or Cartesian (x, y & z) coordinate system and at least two magneto-sensitive elements, in which the magnet can move in relation to said two magneto-sensitive elements. The invention is characterized in that at least one dimension of the magnet varies as a non-constant function and in that the magnetization of the magnets is oriented in a single direction, i.e. x, y or z in the case of a magnet defined in a Cartesian coordinate system or r, Q or z in the case of a magnet defined in a cylindrical coordinate system.
    Type: Grant
    Filed: November 26, 2007
    Date of Patent: February 12, 2013
    Assignee: Moving Magnet Technologies
    Inventor: Didier Frachon
  • Patent number: 8339003
    Abstract: The invention relates to a gear motor including a multiple-phase electric motor formed by a stator portion excited by electric coils and by a rotor having N pairs of poles radially magnetised in alternating directions, the stator portion including two angular sectors alpha-1 and alpha-2 with respective radii R1 and R2, and wide teeth and narrow teeth radially extending from an annular crown, characterized in that the wide teeth have a width higher than or equal to twice the width of the narrow teeth, in that the notch width is higher than the width of a narrow tooth, in that the angular sector alpha-1 is lower than 220° and includes all the coils, and in that the ratio R1/R2 ranges from 1.2 to 2.
    Type: Grant
    Filed: July 11, 2008
    Date of Patent: December 25, 2012
    Assignee: Moving Magnet Technologies
    Inventor: Daniel Prudham
  • Patent number: 8102093
    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.
    Type: Grant
    Filed: March 28, 2007
    Date of Patent: January 24, 2012
    Assignee: Moving Magnet Technologies (MMT)
    Inventor: Daniel Prudham
  • Publication number: 20110254543
    Abstract: 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.
    Type: Application
    Filed: September 28, 2009
    Publication date: October 20, 2011
    Applicant: Moving Magnet Technologies (MMT)
    Inventors: Didier Frachon, Gérald Masson, Stéphane Biwersi
  • Patent number: 7906959
    Abstract: A variable reluctance analog position device designed to determine the position variation of a target made from a ferromagnetic material. The device includes at least one magnet, the target and the magnet defining a gap therebetween. A magnetosensitive element detects induction variation produced in the gap by relative movement of the target relative to the magnet. The magnet is magnetized in a direction essentially perpendicular to the front surface of the magnet, which defines one edge of the gap. The magnet includes a cavity open at the front surface thereof and the magnetosensitive element is housed in the cavity. Moreover, the target is provided with a specific geometric configuration determined such that the induction variation according to the position of the target corresponds to a pre-defined function.
    Type: Grant
    Filed: October 7, 2003
    Date of Patent: March 15, 2011
    Assignee: Moving Magnet Technologies
    Inventors: Didier Frachon, Pierre Gandel
  • Patent number: 7898122
    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.
    Type: Grant
    Filed: April 6, 2006
    Date of Patent: March 1, 2011
    Assignee: Moving Magnet Technologies (MMT)
    Inventors: Gael Andrieux, Stephane Biwersi
  • Publication number: 20110031824
    Abstract: The invention relates to a gear motor including a multiple-phase electric motor formed by a stator portion excited by electric coils and by a rotor having N pairs of poles radially magnetised in alternating directions, the stator portion including two angular sectors alpha-1 and alpha-2 with respective radii R1 and R2, comprising wide teeth and narrow teeth radially extending from an annular crown, characterised in that the wide teeth have a width higher than or equal to twice the width of the narrow teeth, in that the notch width is higher than the width of a narrow tooth, in that the angular sector alpha-1 is lower than 220° and includes all the coils, and in that the ratio R1/R2 ranges from 1.2 to 2.
    Type: Application
    Filed: July 11, 2008
    Publication date: February 10, 2011
    Applicant: Moving Magnet Technologies
    Inventor: Daniel Prudham
  • Publication number: 20100231205
    Abstract: A magnetic sensor of rotary, linear, or curvilinear displacement using at least one permanent magnet and at least one magnetosensitive element, which can move with respect to one another. The magnet exhibits a direction of magnetization that varies continuously along the direction of displacement, with the exclusion of a diametral magnetization in the case of a rotary sensor.
    Type: Application
    Filed: March 2, 2007
    Publication date: September 16, 2010
    Applicant: Moving Magnet Technologies (MMT)
    Inventors: Nikola Jerance, Richard Arlot
  • Patent number: 7784365
    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.
    Type: Grant
    Filed: January 8, 2007
    Date of Patent: August 31, 2010
    Assignee: Moving Magnet Technologies (MMT)
    Inventors: Gerald Masson, Stephane Biwersi
  • Patent number: 7644635
    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.
    Type: Grant
    Filed: July 11, 2005
    Date of Patent: January 12, 2010
    Assignee: Moving Magnet Technologies
    Inventors: Daniel Prudham, Gerald Masson, Antoine Foucaut
  • Patent number: 7589445
    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.
    Type: Grant
    Filed: March 4, 2003
    Date of Patent: September 15, 2009
    Assignee: Moving Magnet Technologies, M.M.T.
    Inventors: Pierre Gandel, Daniel Prudham, Jean-Daniel Alzingre, Antoine Foucaut
  • Publication number: 20090174280
    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.
    Type: Application
    Filed: March 28, 2007
    Publication date: July 9, 2009
    Applicant: Moving Magnet Technologies (MMT)
    Inventor: Daniel Prudham
  • Patent number: 7432682
    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.
    Type: Grant
    Filed: November 3, 2004
    Date of Patent: October 7, 2008
    Assignee: Moving Magnet Technologies
    Inventors: Eric Rondot, Daniel Prudham
  • Patent number: 7304450
    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.
    Type: Grant
    Filed: October 5, 2001
    Date of Patent: December 4, 2007
    Assignee: Moving Magnet Technologies
    Inventor: Daniel Prudham
  • Publication number: 20070132422
    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.
    Type: Application
    Filed: November 3, 2004
    Publication date: June 14, 2007
    Applicant: Moving Magnet Technologies
    Inventors: Eric Rondot, Daniel Prudham
  • Patent number: 7028545
    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.
    Type: Grant
    Filed: February 27, 2002
    Date of Patent: April 18, 2006
    Assignee: Moving Magnet Technologies (S.A.)
    Inventors: Pierre Gandel, Didier Frachon, Didier Angleviel, Claude Oudet, Daniel Prudham