Abstract: A magnetic bearing is disclosed that includes a sensing wire wrapped around one or more of the bearing coils and configured to measure the resistance to ground of each bearing coil. With the presence of contaminants such as liquids, a protective coating disposed about the bearing coils degrades over time, thereby reducing the resistance to ground of the bearing coils. The sensing wire transmits the detected resistance to ground of the bearing coils to an adjacent sensing device, which can provide an output that informs a user whether corrective action is required to prevent damage or failure of the magnetic bearing.

Abstract: The present disclosure describes a mechanical backup bearing system arrangement to work in conjunction with non-contact magnetic bearings and capable of coping with thermal expansions of the bearing components during operations. Expansions or contractions of an inner or outer race of a bearing can be compensated using particular springs providing a low profile and a proper stiffness. An electric machine system includes a rotational portion and a stationary portion. The electric machine further includes a magnetic bearing configured to support the rotational portion to rotate within the stationary portion. A mechanical back-up bearing resides in a cavity between the rotational portion and the stationary portion. A flat spring is carried by the stationary portion and abutting the back-up bearing.

Abstract: A magnetic bearing retains a rotatable shaft in a selected position by magnetic coupling between a circular magnet and one or more magnet arrays. Each magnetic coupling completes a magnetic circuit. The magnet arrays focus magnetic flux towards the circular magnet to facilitate magnetic coupling. Magnet arrays configured in Halbach series may be employed. Magnet arrays configured as electromagnets may also be employed. The shaft may be attached either to the circular magnet or the magnet arrays. Shaft rotation does not affect the magnetic circuit, but axial displacement of the shaft disrupts the magnetic circuit and increases magnetic reluctance. Increasing magnetic reluctance inhibits axial displacement. The shaft thereby supports a load while rotating freely, constrained to a selected position by forces of magnetic reluctance. A centering bearing may be employed to maintain gap distance between circular magnet and one or more magnet arrays.

Abstract: An AC current generator for generating an CA current and method therefor and includes a stator and a rotor. The stator includes an outer shell of non-magnetic material enclosing an evacuated chamber and having a distribution of a plurality of ferromagnets attached thereto. The rotor includes an inner core of non-magnetic material located at a stability location within said evacuated chamber and having a distribution of a plurality of diamagnets attached thereto. In addition, the AC current generator includes at least one magnetic flux detection unit located within at least one magnetic field generated by at least one group of ferromagnets of the plurality of ferromagnets. Displacing the rotor from the stability location towards the at least one group of ferromagnets generates a change in magnetic flux in the magnetic field thereby generating an AC current in the at least one magnetic flux detection unit.

Abstract: Disclosed is a hybrid pole bearingless switched reluctance motor (BLSRM). The BLSRM includes a stator provided with windings, a rotor rotating about an axis when current is conducted to the windings. The rotor includes a plurality of rotor poles extending radially outward, and the stator includes a plurality of stator poles extending radially inward. The windings include suspending windings to generate radial force for the rotor and torque windings to generate torque. The suspending windings are mutually separated from the torque windings. Through the use of the hybrid pole BLSRM, a stator pole generating the radial force can be controlled independently from the stator pole generating the torque by separately arranging the stator pole generating the radial force and the stator pole generating torque based on the analysis of radial force and torque characteristics according to the position of the stator poles.

Abstract: A machine having a stator and a rotor having a rotor shaft supported in bearings, such that the rotor is rotatable about a rotation axis. The bearings are designed as active magnetic bearings in which the rotor is supported without contact. A respective back-up bearing is associated with each active magnetic bearing to catch the rotor when the respective active magnetic bearing fails. The respective back-up bearing has a bushing arranged on the rotor shaft and a sliding device arranged on the stator. The respective bushing has an inner ring arranged radially inside to fasten the bushing on the rotor shaft, and an outer ring that surrounds the inner ring radially outside and slides in the sliding device of the respective back-up bearing when the respective active magnetic bearing fails. The inner and outer rings are made of different materials and are connected to each other in a bonded manner.

Abstract: In a jacketed active magnetic bearing for a rotary machine having a rotor in contact with a process gas, there is provided a magnetic bearing comprising a bearing armature of laminated magnetic material secured to said rotor, a bearing stator protected by a first jacket of magnetic anti-corrosion material that co-operates with first housing portions to form a first leaktight housing enclosing the bearing stator, the first jacket being made of a ferritic stainless steel, and the first housing portions having insert parts that are also made of ferritic stainless steel, and that are connected by welds to a housing end-wall portion made of a magnetic anti-corrosion material, the laminated magnetic material forming the bearing armature and the detector armature also being a ferritic stainless steel.

Abstract: A magnetic bearing apparatus is proposed having a stator (2) which includes a winding (22) for the generation of a magnetic control field, having a rotor (3) which can be magnetically journalled with respect to the stator (2) and also having a sensor device (5) configured as an eddy current sensor for the determination of the distance between the stator (2) and the rotor (3), wherein the sensor device (5) includes at least one sensor element (51) configured as an inductor and at least one capacitor (53) which forms an electrical resonant circuit with the inductor, and also having a monitoring unit (6) for the control of the sensor device (5) and for the evaluation of the detected signals. The inductor is arranged electrically in series to the capacitor (53) so that the electrical resonant circuit is a serial resonant circuit.

Abstract: A resistance to ground monitoring system for a magnetic bearing is disclosed. The system includes a dummy bearing arranged in a cooling loop and having a dummy bearing coil made up of an electrical winding that is configured to detect the resistance to ground for the dummy bearing coil. The electrical winding is communicably coupled to a sensing device that monitors the resistance to ground for the dummy bearing coil. Since the magnetic bearing is arranged within the same cooling loop, the resistance to ground for the dummy bearing coil is indicative of a resistance to ground for the radial bearing coils of the magnetic bearing.

Abstract: An electric motor for operating a small electric device is disclosed. The electric motor includes at least one first oscillatory motor component; an inductor for producing a magnetic field; and a first magnet arrangement including a first permanent magnet that generates a force for activating a rotatory oscillating movement (R) of the at least one first oscillatory motor component around a rotating axis (z). The at least one first oscillatory motor component and the first magnet arrangement are configured such that a magnetic reluctance torque acting between the first oscillatory motor component and the first permanent magnet operates as a righting moment for the rotatory oscillating movement (R).

Abstract: A permanent magnet rotor shaft assembly for a high speed electrical machine provides a permanent magnet cylindrical core having a longitudinal axis, the cylindrical core being axially compressed by first and second end shafts and being radially compressed by a sleeve made of a non-magnetic high strength metal. At least one of the first and second end shafts includes, facing the cylindrical core, a central shoulder head that cooperates with a mating central recess made in a central portion of a front face of the cylindrical core. An easy concentric alignment of the first and second end shafts with the permanent magnet cylindrical core is allowed while inserting the sleeve and the stiffness of the assembled set is enhanced.

Abstract: A magnetic bearing thrust stator is provided including, a plurality of stator sectors. Each of the stator sectors includes a semi-circumferentially slotted stator portion including a plurality of semi-circumferential poles and a first coil portion shaped to fit substantially within the semi-circumferentially slotted stator portion.

Abstract: A magnetic bearing system (120) includes a first active magnetic bearing (AMB) (202) including a first group of electromagnetic actuators (306, 310, 314, 318) to support a shaft and a second AMB (204) including a second group of electromagnetic actuators (308, 312, 316, 320) to support the shaft. A controller for the two AMB's includes a multi-phase topology (400) with a plurality of active current switches for controlling the electromagnetic actuators (306-320) of each of the first AMB (202) and the second AMB (204). Each electromagnetic actuator (306, 310, 314, 318) of the first AMB (202) is electrically coupled to an electromagnetic actuator (308, 312, 316, 320) of the second AMB (204).

Abstract: For an object on a bearing mounting having a magnetic bearing providing a magnetic field generally produced by an electromagnet, the bearing is regulated based on a position of the object relative to the bearing. The position of the object is determined by reference to an estimate of the inductance obtained using a least squares method, in which the electrical resistance of the bearing is taken into account. The resistance is subject to variations, for example due to temperature fluctuations; however, the electrical resistance can be estimated by regulating the inductance error, ?{circumflex over (L)}={circumflex over (L)}2,sLS?{circumflex over (L)}1,sLS down to zero, where the resistance adjustment facility may be a low-pass filter and an integration controller.

Abstract: A motor includes a rotor module and a stator module. The rotor module includes a plurality of first magnet units, a plurality of second magnet units, a hollow magnetic conductance pillar and a rotating shaft. The first and second magnet units are alternately arranged to form a hollow pillar. An outer surface of the hollow pillar includes a plurality of first surfaces and second surfaces of the first and second magnet units. The first and second surfaces have different magnetic poles. The hollow magnetic conductance pillar and the rotating shaft are disposed in and through the hollow pillar and the hollow magnetic conductance pillar, respectively. The stator module includes a shell and a coil unit. The rotor module is disposed in the shell and the rotating shaft is extended out of the shell. The coil unit is disposed on an inner surface of the shell and around the rotor module.

Abstract: Rotating machines and magnetic thrust bearings therefor are disclosed. Magnetic thrust bearings may include a rotor core configured to extend coaxially around a shaft of a rotating machine, a non-magnetic element configured to be coaxially disposed on the shaft, and a stator comprising a stator core and a coil, both of which are configured to extend coaxially around the axis. The rotor core may include a substantially radially extending thrust face and a substantially axially extending peripheral surface. The non-magnetic element may radially space the thrust face from the shaft. The stator core may include a substantially radially extending first pole surface and a substantially axially extending second pole surface. The first pole surface may define an axial air gap with the thrust face, and the second pole surface may define a radial air gap with the peripheral surface.

Abstract: A magnetic bearing device comprises a first carrier generation section generating a first carrier signal; a second carrier generation section generating a second carrier signal whose phase differs by (?/2+?) radian from the phase of the first carrier signal; a first demodulation section performing demodulation by sampling the first modulated signal at sampling timing shifted by a phase ? from timing at which the first carrier signal becomes a peak; a second demodulation section performing demodulation by sampling the second modulated signal at sampling timing shifted by a phase (??) from timing at which the second carrier signal becomes a peak; and a controller controlling current in each of the first radial electromagnet and the second radial electromagnet, based on a result of the demodulation by each of the first demodulation section and the second demodulation section.

Abstract: An energy storage system is generally disclosed. An example system includes a flywheel having a substantially cylindrical flywheel portion, and a housing defining a substantially cylindrical cavity configured so as to receive the substantially cylindrical flywheel portion. The flywheel is rotatable in the cavity about a central axis of the flywheel, and an energy exchange device is configured to convert between electrical energy and kinetic energy associated with rotation of the flywheel. The system may also have a magnetic restraint arranged to exert a magnetic restraining force on the flywheel in a direction towards the central axis.

Abstract: An assembly includes a rotating shaft supported with respect to a stationary housing by at least one active magnetic bearing presenting a mean radial air gap and at least one auxiliary bearing having first and second coaxially arranged annular surfaces is provided. One of the first and second coaxially arranged annular surfaces defines a clearance (E2) with one of the stationary housing and the rotating shaft, the clearance (E2) being less than the mean radial air gap and the other of the first and second coaxially arranged annular surfaces being integral with the other one of the stationary housing and the rotating shaft. The auxiliary bearing provides a first ball bearing and a second ball bearing having a misalignment with respect to each other in order to increase the starting torque.

Abstract: A system for suspending a rotating body consisting of a combination of magnetic and engineered materials. The suspension system allows for some axial motion to account for varying system loads.

Abstract: A superconductor-magnet bearing system can include a first bearing portion and a second bearing portion. One of the first and second bearing portions can be at least partially composed of a high-temperature superconductor (HTS) and another can be at least partially composed of a magnet. The first bearing portion can be disposed at least partially within an opening of the second bearing portion with a gap between the first and second portions. A magnetic bearing portion can include a plurality of rings disposed next to one another. An HTS bearing portion can include a magnet. The bearing portions can be biased toward an alignment with one another. One bearing portion can rotate relative to another bearing portion.

Abstract: An improved rotary disc atomizer for use in, for example, spray dryers or congealers is disclosed. The rotary disc may be directly mounted to the shaft of a high-speed electrical motor. The high-speed electrical motor comprises a permanent magnet rotor and electro-magnetic bearings. The electro-magnetic bearings may be supported by one or more upper/lower bearing housings and used to enable frictionless support of the shaft/rotor and rotary disc. The atomizer system may further comprise a gas distributor enabled to dynamically adjust the velocity at which the gas leaves the radial vanes and meets with the atomized droplets.

Abstract: Methods and apparatuses are disclosed for incorporating a plurality of independently rotating rotors made from high-strength materials with a high-temperature superconductive (HTS) bearing technology into an open-core flywheel architecture to achieve a desired high energy density in the flywheel energy storage devices and to obtain superior results and performance.

Abstract: A magnetic bearing body supports a rotating shaft using a combined electromagnetic force of a pair of control electromagnets without contact. A controller detects a control index value based on a first coil current passed through a coil of a first control electromagnet of the pair of control electromagnets which generates an electromagnetic force in the same direction as that of a load exerted on the rotating shaft, the control index value being an index of the degree of margin for error in control depending on a value of the first coil current. And the controller controls a middle value of a pair of coil currents passed through the respective corresponding coils of the pair of control electromagnets so that the control index value approaches a predetermined target index value.

Abstract: The present invention relates to a composite magnetic bearing having an auxiliary bearing coupled thereto, which has an improved structure for minimizing a length of a rotor and a system volume. The composite magnetic bearing of a radial type provided around a rotor having an auxiliary bearing coupled thereto for reducing friction, includes a magnetic bearing, and an auxiliary bearing fixed in the empty space in an inside of the stator cores on an inner side of a position the coils and the permanent magnets are provided thereto.

Abstract: An assembly that includes a rotating shaft supported with respect to a stationary housing by at least one active magnetic bearing presenting a mean radial air gap and at least one auxiliary bearing having a bushing fixed to the housing and a sleeve fixed on the rotating shaft. The bushing and the sleeve have opposite surfaces that define a clearance (E2) which is less than the mean radial air gap (E1). The bushing and the sleeve each exhibit symmetry around a longitudinal axis of the shaft and have different profiles in a longitudinal cross-section including the longitudinal axis to optimize the contact pressure distribution when the rotating shaft lands on the auxiliary bearing.

Abstract: An energy recovery system may comprise a stationary structure and a rotatable structure configured to rotate relative to the stationary structure about an axis of rotation. The energy recovery system may also comprise at least one blade member mounted to and extending radially outward from the rotatable structure, the at least one blade member being configured to interact with fluid currents flowing in a direction substantially parallel to the axis of rotation to cause the rotatable structure to rotate about the axis of rotation. The energy recovery system may further comprise a magnetic suspension system comprising a plurality of magnets and a plurality of coils, wherein the plurality of magnets and the plurality of coils provide a magnetic force that substantially maintains an axial and radial position of the rotatable structure and the stationary structure as the rotatable structure rotates about the stationary structure.

Abstract: An active magnetic bearing includes a bearing housing, a bearing stator, a bearing armature, a position detector, a jacket, and a stress buffering member. The bearing stator is accommodated in the bearing housing to support rotation of a rotor by using a magnetic force. The bearing armature is disposed to be spaced apart from the bearing stator by an interval and fixed to the rotor. The position detector is installed in the bearing housing to detect a position of the rotor. The jacket is interposed between the bearing stator and the bearing armature to seal a space between the bearing stator and the bearing housing. The stress buffering member connected to opposite ends of the jacket and the bearing housing, to buffer a stress generated due to differences between thermal exposition coefficients and temperatures of the bearing housing and the jacket.

Abstract: The invention relates to an easily mountable and highly dynamic radial bearing. According to the invention, a magnetic radial bearing for the rotatable mounting of a rotor (3) is provided, having a stator (2) that comprises several coil assemblies (6). The coil assemblies (6) are arranged around an axis (1) of the radial bearing in a circumferential direction. Each of the coil assemblies (6) has a laminated core (7) having single sheets. Each of the coil assemblies (6) further has an axial field coil (11) that is wound around the corresponding laminated core (7). The single sheets are stacked in the tangential direction in every laminated core (7).

Abstract: In a method for operating a three-phase inverter of a converter-fed magnetic bearing, two coils are connected to respective outputs of the three-phase inverter at one end and are connected to each other and to a third output of the three-phase inverter at the other end. A variable control current is injected into the third output. A constant bias current flows between the respective outputs and thus serially through the two coils. The control current is divided among the two respective outputs so as to flow parallel through the two coils. This arrangement significantly reduces the effective current load of the three-phase inverter and significantly increases the slew rate of the control current.

Abstract: A bearing, which has a first bearing ring, a second bearing ring, a rolling element interposed between the two bearing rings and a claw pole generator-type power generation unit. The bearing has a substantially space-neutral power generation unit which has a high filling factor for the induction coil. The first claw of the claw ring is connected to a magnetically conducting section of the body of the first bearing ring in a magnetically conducting fashion. The magnetic poles of the pole pairs are mounted so as to be connected to a magnetically conducting section of the body of the second bearing ring in a magnetically conducting fashion and the magnetic circuit is substantially closed via the two magnetic sections and the rolling element.

Abstract: A magnetic suspension planar motor comprises a structure of superconductor excitation. A primary base plate is in a shape of board. Armature windings are fixed on an air gap side of the primary base plate. A secondary base plate in a secondary structure is evenly divided into 2 h*2 h magnet cells. 2 h2 superconducting magnets are respectively fixed in the magnet cells on the secondary base plate, which resembles a checkerboard pattern. The superconducting magnets are adjacent to each other, neither in a horizontal direction nor in a vertical direction. The superconducting magnets are magnetized parallelly, and magnetization directions of the superconducting magnets are perpendicular to a surface on an air gap side of the secondary base plate. The superconducting magnets in a same row or column have same magnetization directions, and the superconducting magnets in adjacent rows columns have contrary magnetization directions. A cooling container shields all of the superconducting magnets.

Abstract: A bearing, which has a first bearing ring, a second bearing ring and a claw pole generator-type power generation unit. The bearing has a substantially space-neutral power generation unit, which has a high filling factor for the induction coil. Every claw ring is connected to a section of the body of the first bearing ring in a magnetically conducting fashion and the magnetic circuit is substantially closed via the section of the body of the first bearing ring.

Abstract: A process of forming an encapsulated magnet assembly is provided, the process comprising welding a second portion of a housing cover formed of a non-magnetic material to a first portion of a housing cover formed of a magnetic material to provide a welded housing cover and subsequently heat-treating the welded housing cover at a temperature effective to relieve weld stress; disposing a magnet within a housing comprising at least one wall formed of the non-magnetic material and defining at least one aperture; and welding the heat treated welded housing cover to the housing such that the second portion of the housing cover is fixedly attached to the housing wall to hermetically seal the aperture. In one embodiment, the magnet of the encapsulated magnet assembly is a permanent magnet, and in an alternate embodiment an electromagnet. In one embodiment the encapsulated magnet assembly is a component of a stator-rotor assembly.

Abstract: A method for assembling a superconducting bearing, wherein the superconducting bearing has a first bearing ring including a first body made of a type-2 superconducting material and a second bearing ring including a second body made of a type-2 superconducting material, the method including the following steps: assembling the first bearing ring and the second bearing ring; and, applying an external magnetic field, which permeates both bodies to the first body and to the second body.

Abstract: Provided is a radial direction controller capable of handling changes in negative bearing stiffness according to the mounting orientation.

Abstract: A method and system for transportation using a magnetic bearing structure is disclosed. In one aspect, there is an apparatus for carrying a load along a magnetizable structure. In one embodiment, the apparatus comprises a third structure spaced apart vertically from the magnetizable structure and configured to generate magnetic flux and repel from the magnetizable structure. In one embodiment, the apparatus comprises at least one coil positioned at at least one end portion proximal to the magnetizable structure. In one embodiment, the apparatus comprises at least one flux guide comprising a magnetizable material and configured to concentrate magnetic flux. A first portion of the flux guide is thinner than a second portion of the flux guide that is positioned closer to the magnetizable structure than the first portion of the flux guide.

Abstract: A first bias magnetic flux may be communicated between a first axial pole and a first axial facing surface of the body. A second bias magnetic flux may be communicated between a second axial pole and a second axial facing surface of the body. A time-varying axial control magnetic flux may be communicated through the first and second axial facing surfaces of the body, and may be generated in a magnetic circuit including the body, the first and second axial poles, and an axial magnetic backiron. The first and second axial poles may include axial pole laminated inserts composed of electrically isolated steel laminations stacked along the body axis. The axial magnetic backiron may include laminated inserts composed of electrically isolated steel laminations stacked in the direction tangential to the body axis. The axial pole laminated inserts may be magnetically coupled to the axial magnetic backiron laminated inserts.

Abstract: The present invention provides an encapsulated magnet assembly, comprising (a) a magnet disposed within a housing, said housing comprising at least one wall and defining at least one aperture; and (b) a housing cover; the housing cover comprising a first portion made of a magnetic material and a second portion made of a non-magnetic material, wherein the housing cover is configured to hermetically seal said aperture, the first portion being fixedly attached to the second portion wherein a point of attachment is heat treated; and wherein the housing wall is formed of the non-magnetic material and is fixedly attached to the second portion of the housing cover. In one embodiment, the magnet of the encapsulated magnet assembly is a permanent magnet, and in an alternate embodiment an electromagnet. In one embodiment the encapsulated magnet assembly is a component of a stator-rotor assembly.

Abstract: The invention relates to a method for correcting variations of parameters of components of active magnetic bearing and/or assembly of active magnetic bearing as a whole. At the latest before starting to operate the active magnetic bearing are detected mechanical and/or electrical and/or installation variations and/or other variations of parameters of at least one component of the active magnetic bearing and/or of the whole active magnetic bearing assembly, whereupon the detected variations and/or correction values based on the variations are recorded in memory (M), which is an integral part of the active magnetic bearing assembly, and subsequently these variations and/or correction values are used from the memory (M) for adjustment of system for detecting position of the rotating working means in the active magnetic bearing during operation of the active magnetic bearing.

Abstract: An electromagnetic actuator can exert a radial electromagnetic force on a body that is configured to rotate about a rotational axis. The actuator includes a radial control magnetic pole assembly that includes radial control poles adjacent to and spaced apart by air gaps from the body. The actuator includes a permanent magnet (PM) magnetized along the axis, having one pole in contact with an axial face of the assembly and located proximate to a lateral surface of the body. The PM is magnetically coupled to the body in a non-contact manner resulting in a bias magnetic flux in the air gaps. The actuator includes a control coil around the radial control poles located radially outwards from the PM. Electrical current in the coils generates control magnetic flux in air gaps. The non-uniform net magnetic flux distribution around the body results in a radial electromagnetic force exerted on the body.

Abstract: A magnetic lifting device is described. The magnetic lifting device can be configured to generate magnetic lift using a moving magnetic field to generate an eddy current effect in conductive substrate beneath the device. In one embodiment, the moving magnetic field can be generated by a rotor with arrangement of permanent magnets which is driven by a motor. In operation, the rotor can be spun up from rest to above a threshold velocity, which causes the magnetic lifting device to rise up from the conductive substrate, hover in place in free flight and move from location to location. In free flight, the magnetic lifting device can be configured to carry a payload, such as a person.

Abstract: A method of arranging a diamagnetic rod includes levitating a diamagnetic rod above a contact line at which a first magnet contacts a second magnet, the first magnet and the second magnet having diametric magnetization in a direction perpendicular to the contact line.

Abstract: Electrostatic stabilizers are provided for passive bearing systems composed of annular magnets having a net positive stiffness against radial displacements and that have a negative stiffness for vertical displacements, resulting in a vertical instability. Further embodiments are shown of a radial electrostatic stabilizer geometry (using circuitry similar to that employed in the vertical stabilizer). This version is suitable for stabilizing radial (lateral) displacements of a rotor that is levitated by annular permanent magnets that are stable against vertical displacements but are unstable against radial displacements.

Abstract: A magnetic bearing (108) with an axis of rotation (106), wherein the magnetic bearing comprises: a cylindrical rotor (116) comprising a ferromagnetic material (118, 338, 440) wherein the cylindrical rotor has an axis of symmetry (114), wherein the cylindrical rotor has an inner radius (124), wherein the cylindrical rotor has a top side (128), a static hub (120), wherein the static hub has an overhang (122) which protrudes from the static hub and is located adjacent to the top side, a lift magnetic actuator apparatus (130) for controlling the distance (126) between the top side and the overhang, a radial magnetic actuator apparatus (132) for controlling the distance (136) between the inner radius and the axis of rotation.

Abstract: Disclosed herein is a linear vibrator, including: a stator including a coil; and a vibrator including a magnet opposite to the coil, wherein the linear vibrator is linearly vibrated due to electromagnetic induction of the coil and the magnet, the magnet is formed in a disc shape in which a cut part is formed by cutting a portion thereof, a magnetic fluid band is formed on an outer peripheral surface of the magnet, and a portion of the magnetic fluid band is in contact with the coil. According to the present invention, there is provided the linear vibrator capable of suppressing weak vibration generated at the time of external impact or movement, previously preventing noise generated as the vibrator applies an impact to the stator due to excessive vibration, and minimizing attenuation of the linear vibration quantity as the cut part that is formed by cutting a portion of the magnet to form the air gap with the coil.

Abstract: In a rotating machine, a recording disk is mounted on a hub. A base rotatably supports the hub through a bearing unit. A core is fixed to the base and includes an annular portion and a salient pole radially extending therefrom. A coil is formed by winding a wire around the salient pole. The wire is pulled out to the back surface of the base through a pull-out hole provided in the base and soldered to a wiring.

Abstract: A rotating electrical machine includes a stator, a rotor and at least one active magnetic bearing including a bearing winding, which is an air-gap winding, and includes at least a first phase winding and a second phase winding. A measurement arrangement measures the radial displacement of the rotor by injecting a displacement measurement injected signal into at least one section of at least one of the bearing windings of one of the magnetic bearings, and capturing at least one displacement measurement signal wherein this displacement measurement signal depends on the rotor displacement in a radial direction relative to the stator, this dependency being due to eddy currents in the rotor induced by the displacement measurement injected signal.

Abstract: A rotary pump including an impeller rotatable within a housing. A load is imposed on the impeller as it rotates, in a direction that is substantially parallel to the axis of rotation and wherein the load stabilises the motion of the impeller. The load may be achieved by magnetically biasing the impeller.

Abstract: Stabilizing techniques are provided that prevent whirl-type instabilities during the operation of magnetically levitated rotating systems. Examples include tensioned foil and tensioned wire based designs, where a restraining force arises from contact between a rotating shaft and the tensioned elements, which elements may be of either metallic or non-metallic composition. Another stabilizing technique provides a variation with azimuth in the tension of an array of foils (or wires) so as to create anisotropic stiffness for displacements that are 90° apart in azimuth. Another exemplary technique restrains displacements that have components that are transverse to (i.e., parallel with) the axis of rotation.