283results about How to "Reduce leakage flux" patented technology

A stator or a rotor for an electrical machine comprises a plurality of circumferentially separated, radially extending teeth, wherein each tooth having a single winding and is provided with an axially and radially extending reluctance barrier to increase the reluctance of each tooth regarding propagation of a magnetic field not interacting with the winding of said tooth.

The embodiment of the invention discloses a composite magnetic core structure and a magnetic element, which are used for reducing magnetic core loss and increasing the frequency of application. In the embodiment of the invention, the composite magnetic core structure consists of a first magnetic core part and a second magnetic core part, the first magnetic core part is made of low-magnetic permeability soft magnetic material, the second magnetic core part is made of high-magnetic permeability soft magnetic material, and the first magnetic core part and the second magnetic core part are combined and formed into a magnetic flux loop.

A power transmission device includes: a high speed magnet rotor which includes a magnet array which is magnetized in a radial direction; a low speed magnet rotor which includes a magnet array which is magnetized in a circumferential direction; and an inductor rotor which allows magnetic fluxes from the magnet array of the high speed magnet rotor to pass, and the high speed magnet rotor, the low speed magnet rotor and the inductor rotor are concentrically arranged and the magnet array of the low speed magnet rotor is formed such that homopolar surfaces of neighboring magnets face each other in the circumferential direction.

In the prior art in which permanent magnets are regularly arranged over the whole circumference of a rotor core, a satisfactory magnetic flux distribution is hard to obtain, and the cogging torque and the distortion factor of the induced electromotive force waveform are large, whereby characteristics of a rotating electric machine are poor. Also, because the permanent magnets are arranged over the whole circumference, a large number of permanent magnets are required and cost reduction is difficult. A permanent magnet rotating electric-machine of the invention comprises a stator provided with a plurality of windings, and a rotor in which magnets are disposed in slots formed in a rotor core along an outer circumference thereof, the rotor core being fixed on a rotary shaft rotating inside the stator, and in which one magnetic pole is constituted by each group of three or more of the magnets. A total angle occupied by the group of magnets constituting one magnetic pole is in the range of 150 to 165 degrees in terms of an electrical angle.

A Lundell type rotor core with a pair of side cores and a magnetic-pole cylindrical portion has a structure in which the magnetic-pole cylindrical portion is mated between both the side cores (also referred to as “pole cores”) in a radial direction at an outside of a field coil wound on a boss portion in the side cores. The magnetic-pole cylindrical portion is made of plural magnetic steel sheets laminated in the axis direction, and is easily deformed rather than both the side cores. The easy deformation characteristic of the magnetic-pole cylindrical portion prevents generation of a gap during the assembling process of the magnetic-pole cylindrical portion and the side cores. Without paying strict dimension control of the components for the rotor core, it is easily possible to prevent any generation of a gap between the side cores and the magnetic-pole cylindrical portion while assembling. It is thereby possible to prevent a deterioration of a magnetic flux flowing in the rotor core.

A stator includes a ring-shaped stator core and a stator winding. The stator core has a plurality of slots arranged in a circumferential direction. The stator winding has a plurality of phase windings. Each phase winding is composed of a plurality of segment conductors 41 disposed such as to be inserted into the slots and connected in series. The segment conductor is divided into two. The phase winding is configured by two divided phase windings connected to each other in parallel. The divided phase windings are respectively configured by a plurality of segment conductors respectively connected in series such that the two divided segment conductors are in parallel with each other.

The invention discloses a short-circuit fault-tolerant vector control method for an embedded hybrid magnetic material fault-tolerant cylindrical linear motor. The short-circuit fault-tolerant vector control method comprises the following steps: building a five-phase embedded hybrid magnetic material fault-tolerant cylindrical linear motor model; compensating normal thrust missing caused by a short-circuit fault phase and suppressing a thrust ripple caused by phase short-circuit current with non-fault phase current of the motor; and obtaining expected phase voltage by adopting a series of coordinate conversion and voltage feed-forward compensation strategies, and achieving a fault-tolerant vector control after the phase short-circuit fault of the motor by a zero-sequence voltage harmonic injection-based CPWM modulation mode. According to the short-circuit fault-tolerant vector control method, the motor can suppress the thrust ripple of the motor under the condition of a phase short-circuit fault-tolerant operation; more importantly, the dynamic property, the steady-state performance and the properties in a normal state are consistent; the switching frequency of a voltage source inverter is constant; a CPU is low in overhead; and a natural coordinate system only needs to counterclockwise rotate a certain angle in any phase short-circuit fault, so that the motor fault-tolerant operation can be achieved.

The present invention discloses a stator permanent-magnetic doubly salient disc-type motor, which comprises stator mechanisms, a rotor mechanism and a motor shaft, wherein the rotor mechanism is arranged between the two stator mechanisms, the rotor mechanism and the stator mechanisms are arranged on the motor shaft, each stator mechanism comprises a stator core, two permanent magnets and 2N annular armature windings, 2N stator teeth are evenly distributed on the inner wall of each stator core, a groove between every two adjacent stator teeth is a stator groove, the permanent magnets magnetized in the peripheral direction are arranged in centers of any pair of stator grooves on the same diameter, and the 2N annular armature windings respectively sleeve the 2N stator teeth; and the rotor mechanism comprises a plurality of rotor cores and a non-magnetic-conductive rotor bracket, the plurality of rotor cores are evenly distributed on the outer circumference of the non-magnetic-conductive rotor bracket, and the rotor cores form rotor salient poles. The stator permanent-magnetic doubly salient disc-type motor can effectively improve the reliability of the motor, reduces size and weight of the motor, improves power density and torque density of the motor, and is suitable to be used in occasions with strict requirements on size of generators or motors.

A magnet assembly includes a back iron and an array of magnets. The back iron is in the form of a plate having opposed surfaces. The magnets are arranged along one of the surfaces, with the other surface being dimensioned and configured according to the magnetic field distribution associated with the magnets. The back iron geometry provides for reduced mass, reduced leakage flux, and high flux densities to improve performance of a linear motor that employs such a magnet assembly. Additionally, the back iron can be a magnetically conductive annular ring, such as is employed in a rotary motor. Moreover, the magnets can be arranged in a manner that generates a Halbach array to increase force output in a desired direction while canceling stray magnetic fields in other directions. Similar reduced-mass designs can be employed in conjunction with a back iron of a fixed cross-section and magnets of variable thicknesses, variable lengths, and/or variable widths. In a case where the arrangement is employed in a platen and forcer system, plates on both the platen and forcer may be scalloped to reduce mass.

A lens actuator is provided for moving a movable part including a lens, with respect to a fixed part in the optical axis direction of the lens. The lens actuator includes (a) a magnet disposed on the surface of the movable part facing the fixed part and magnetized in the optical axis direction, (b) a coil disposed on the surface of the fixed part facing the magnet, and (c) a pair of magnetic materials disposed on both sides of the magnet in the optical axis direction, to direct magnetic flux from the magnet toward the coil.

A monolithic ceramic component includes a coil-including region formed by stacking ceramic green sheets for defining inner layers having a porosity of about 30% to about 80%, and outer layer regions formed by stacking ceramic green sheets for defining outer layers have a porosity of about 10% or less. Outer electrodes are provided on the right end surface and the left end surface of a sintered ceramic laminate. That is, the outer electrodes are provided on the main surfaces of outermost ceramic sheets for outer layers.

The invention relates to a flux switching type magnetic-concentration transverse flux permanent magnetic wind generator, in particular to a novel high-performance and direct-driving type transverse flux permanent magnetic wind generator. The generator comprises a stator, a rotor, permanent magnets and a winding. The stator consists of a plurality of stator cores (1) and an armature winding (5), wherein the stator cores (2) are distributed around the rotor. Two adjacent stator cores (1) in the circumferential direction are arranged in bilateral symmetry, and the stator cores are arranged on a casing (7) made from non-magnetic conductive material. Rotor cores (4) are arranged on a barrel (8) made from the non-magnetic conductive material. The barrel is connected with a motor rotary shaft (6), and is connected with a motor casing (7) through a bearing (9). Both sides of the rotor cores (4) are respectively embedded into permanent magnets (2) and (3), and the pole directions are opposite. The pole directions of the permanent magnets (2) and (3) of two adjacent rotor cores (4) in the peripheral direction are opposite. According to the motor structure, the single-phase generator can be manufactured, and the multiple-phase generator also can be manufactured.

The invention provides a magnetic flux switching type transverse magnetic flux permanent magnetism wind mill generator, which is a novel transverse magnetic flux permanent magnetism wind mill generator which is high in power density and torque density and is directly driven. A stator consists of a plurality of stator cores(1) distributed around a rotor and an armature winding(4); each stator core(1) is U-shaped, both sides of the stator core(1) are embedded with a first permanent magnet(2) and a second permanent magnet(3), and magnetic pole directions of the two permanent magnets are opposite; the ring-shaped winding(4) is arranged in the stator; the magnetic poles of the first permanent magnets(2) of the two adjacent stator cores(1) are opposite, and the magnetic poles of the second permanent magnets(3) of the two adjacent stator cores(1) are also opposite; all rotor cores(5) are the same in size; the two adjacent rotor cores(5) are aligned left and right respectively and arranged at intervals; the rotor cores(5) are made by overlapping silicon steel sheets and arranged on a cylinder(8) made of non-magnetic conduction materials to form the whole rotor; and the rotor is connected with a rotating shaft of a motor (6) and then connected with a shell(7) through a bearing(9).

A non-contact position sensor including a first stator having two magnet facing sides, a second stator having one magnet facing side aligned with the two magnet facing sides along a locus, a hall element between the first and second stators, and two magnets located next to each other along the locus opposite the three magnet facing sides so as to move freely along the locus. When configured as a rotary sensor, an arbitrary angle of usage can be set. When configured as a linear sensor, a magnet can be made thick without increasing leakage of magnetic flux.

To provide a magnetic element the ends of the coil of which can be drawn out from the core easily, is compact, and further, is one in which magnetic saturation does not arise easily. A magnetic element has a core unit provided with a wound coil, a center core 105 inserted into the interior of the inner periphery of the coil, planar cores disposed at both ends of the center core, and a side core disposed between the planar cores and on the outside periphery of the coil. The side core is disposed so as to form an open portion between the two planar cores around the coil, with a recessed portion formed in a surface of the side core facing the coil in which the coil is partially contained.

A linear motor including magnetic-pole teeth which pinch and hold permanent magnets deployed in a displacer, a plurality of iron cores used for continuously connecting the magnetic-pole teeth, windings wound around the plurality of iron cores in batch, and the displacer in which positive and negative magnetic poles of the permanent magnets are arranged alternately. A plurality of magnetic poles including the magnetic-pole teeth and the iron cores are deployed along a longitudinal direction of the displacer. The windings which are common to the plurality of magnetic poles are deployed on the iron cores. The leakage magnetic flux between the adjacent magnetic poles is reduced by making polarities of the plurality of deployed magnetic poles one and the same polarity.