193results about How to "Reduce cogging torque" patented technology

The invention relates to a stator arrangement for an electric machine, particularly a DC motor, comprising a stator body having a stator back yoke ring and a number of stator teeth between which stator slots to receive stator windings are formed, the stator teeth extending radially from the stator back yoke ring and stator poles being formed at the free ends of the stator teeth, the stator teeth being coupled to a sleeve, which extends coaxially to the stator body, at their free ends. The invention also relates to a method for the manufacture of a stator arrangement of this kind and a direct current motor that employs such a stator arrangement.

The invention relates to the generation of electricity from flowing fluid and in the preferred embodiment to a horizontal axis turbine and generator assembly. The present invention is applicable to water turbines and the invention is described in relation to this application. It is however to be appreciated that it is applicable to wind turbines. The present invention provides turbine generator for generating electrical power from flowing fluid comprising a rotatable hub having an external surface and a rotational axis arranged, in use, parallel to the direction of the flow, a plurality of blades mounted on the external surface of the hub and extending radially outwards from the hub; a plurality of magnets mounted on a surface inside the rotatable hub said surface arranged to rotate with the rotatable hub thereby forming a rotor of an electrical generator, and a plurality of non-rotating coils fixed to a stationary cylindrical core within the periphery of the rotatable hub, said coils and core thereby forming a stator of the electrical generator.

The invention belongs to the permanent magnet synchronous generator technology field, and particularly relates to a method for weakening cogging torque of a permanent magnet synchronous generator. The method for weakening the cogging torque of the permanent magnet synchronous generator includes: firstly, optimizing the shape of a permanent magnet motor tooth so as to reduce the cogging torque; then, optimizing a pole arc coefficient; next, using a magnet pole shifting method to reduce a harmonic component of the cogging torque so as to achieve the purpose of reducing the cogging torque; finally, combining the above three steps so as to minimize the cogging torque, building a finite element model of the permanent magnet synchronous generator, and performing analysis and finite element verification on a provided cogging torque suppression method. The method for weakening the cogging torque of the permanent magnet synchronous generator has the advantages of reducing the cogging torque of the permanent magnet synchronous generator on the premise of slightly influencing other properties of the permanent magnet synchronous generator by changing the shape of the tooth and using an optimal pole arc coefficient method and a magnetic pole shifting method in combination, and then reducing starting resistance torque of a direct drive permanent magnet synchronous wind generator, and improves usage rate of wind energy.

Rotor assembly for an electrical machine, wherein a body of generally cylindrical shape having an inner opening for coaxially mounting the body on a shaft, permanent magnets embedded in said body, wherein at least one of the permanent magnets is split in at least two magnet sections which extend from about the inner opening towards the outer periphery of the body and are inclined towards a plane, which extends in a radial direction of the body.

A motor capable of reducing cogging torque depending on teeth of a stator, and a motor manufacturing apparatus for manufacturing this motor. The angles of rolling directions of cores stacked are set so that the phase difference between the phases of cogging torques produced on the cores is 180° so that the cogging torques produced on the cores cancel each other to reduce the total cogging torque in the motor. The motor comprises a laminated core formed by stacking a plurality of cores made from a rolled electromagnetic sheet steel. The cores forming the laminated core have rolling directions different from each other by a specified machine angle determined depending on the number of slots and/or the number of poles, where the specified machine angle is an angle which produces a phase difference of 180° between the phases of cogging torques produced due to magnetic anisotropy of the cores and the arrangement of teeth depending on the number of slots and/or poles of the motor.

In order to improve tranquility and controllability of an iron core-equipped permanent magnet motor with an improvement of a maximum energy product (BH)_max by improving a shape compatibility of a radial anisotropic magnet, there is provided a radial anisotropic magnet manufacturing method of fixing magnet powder in a net shape so as to maintain a magnetic anisotropic (C-axis) angle of a magnet with respect to a tangential line and for performing a deformation with a flow so as to have a predetermined circular arc shape or a predetermined annular shape. Particularly, by performing a deformation with a viscous flow or an extension flow, a deformability of the magnet is improved, and thus a shape compatibility with respect to a thickness is improved. AC-axis angle θ with respect to a tangential direction is controlled at an arbitrary position and an arbitrary angle so as to reduce cogging torque without separating a magnetic pole into segments.

There is provided a permanent magnet rotary motor that can maintain higher torque density and can also reduce cogging torque more greatly than a conventional permanent magnet rotary motor. A pair of end surfaces of each of permanent magnets used for a rotor are substantially parallel to a virtual plane that extends in the radial direction of a rotor core while passing through the centers of a stator core and an arc surface. Then, the length of the arc surface in the peripheral direction of a rotor core and inclinations of inclined surfaces are so determined that a pole arc ratio Ψ₁ of the arc surface and a pole arc ratio ψ₂ of a magnetic pole surface in each permanent magnet satisfy the relation of P/2N≦Ψ₂−Ψ₁≦1.38×P/2N.

A permanent magnet has a D-shaped cross section including an arcuate top surface (22), a flat bottom surface (24), and side surfaces (26, 28). Provided that a plurality of permanent magnets are circumferentially arranged so that a great circle (S) circumscribes the apexes (P) on the arcuate top surfaces (22), the top surface (22) includes a central region which delineates an arc of a small circle (T) off-centered from the great circle, and end regions (22a, 22b) which are positioned outside the small circle (T) and inside the great circle (S).

The invention discloses a built-in permanent magnet motor. Main polar faces and interpolar faces of a rotor of the motor are formed by connecting a plurality of arcs of eccentric circles not concentric with the circle center of the rotor, so that an air gap is adjusted, and a purpose of reducing a cogging torque of the motor is achieved, and higher harmonic during motor operation is reduced according to regular hierarchic air gap thickness variation. According to the motor, quadrature-axis inductance of the motor is increased in a mode of adopting the air gap thickness of the specific interpolar face and keeping the preset widths of the interpolar faces, so that a reluctance torque of the motor is increased, and torsion of the motor is increased.

The invention discloses a rotor of a permanent magnet motor. The rotor comprises a rotor core with a plurality of installation grooves and permanent magnets installed in the installation grooves. The rotor core is provided with a central hole and a plurality of sections of cylindrical surfaces, a magnetic bridge is connected between adjacent cylindrical surfaces, the outside surface of each magnetic bridge is much closer to the central hole of the rotor core relative to the cylindrical surfaces, the outside surface of each magnetic bridge is outwards concave from the installation grooves to form a groove in the magnetic bridge, and the widths of the grooves are smaller than that of those of the installation grooves. Compared with the prior art, the rotor of the permanent magnet motor has the advantages that the magnetic bridges and the grooves are arranged to allow a motor with the rotor to obtain low cogging torque, reversed electromotive force tending to the sine and low load torque pulsation. The rotor has the advantages of being simple in manufacturing process, high in mechanical strength, low in noise and high in demagnetization-resistance performance due to appropriate multi-section arc or the line-section magnetic bridges, and the rotor is applicable to motors of roller washing machines.

The invention relates to a rotor skewed pole structure for a permanent magnet synchronous motor. The rotor skewed pole structure is a multi-section rotor skewed pole structure formed by laminating a plurality of rotor punched sheets together, wherein each rotor punched sheet comprises installation holes and magnet grooves; the installation holes and the magnet grooves are respectively arranged in an area of the rotor punched sheet near the edge at equal intervals; the installation holes of the adjacent rotor punched sheets are staggered and aligned; and the magnet groove is used for installing a magnet. According to the rotor skewed pole structure for the permanent magnet synchronous motor disclosed by the invention, additional tools and moulds are unnecessary; only one set of punching mould is used; the specially-designed punched sheets are specially combined, such that the skewed pole can be realized; and the cogging torque is effectively reduced.

The invention relates to a combined motor stator component and sleeve used for a wet operation pump. The combined motor stator component and sleeve comprises a stator component and a sleeve, wherein the stator component comprises a stator iron core, a stator coil and a pole piece; a plurality stator teeth distributed at intervals extend integrally from the periphery of the stator iron core, one end of the pole piece is connected with the stator teeth in a matching way, the sleeve is integrally injected on the other end of the pole piece, and one or more positioning parts is/are arranged on the end face or the side face of a non-injection sleeve of the pole piece. The invention further relates to an assembly method of the combined motor stator component and sleeve, wherein the pole piece is placed and located in an injection mold, the sleeve is obtained by injection on the pole piece, then the other end of the pole piece is connected in a matching way with the stator teeth to obtain the combined motor stator component and sleeve for the wet operation pump. According to the invention, the pole piece is stably positioned in the injection mold to guarantee the injection molding effect of the sleeve.

The invention provides a motor stator device that comprises a stator, several loops and a rotor. Several tooth parts are set in the stator, and a locating slot is set between the adjacent two tooth parts of the stator wall, every locating slot is distributed with a tooth; every loop surrounds the tooth part of the stators; the rotor is set in inner of the stator for loop to generate electromagnetic attraction when electrified to make rotor rotating; it can increase the fill in ratio of wire, usage efficiency and decrease the rotating torque, but the rigidity will not be effected.

The invnetion provides a permanent magnet synchronous motor, capable of preventing the magnetic force of a stator core from being reduced, and reducing the torque of a tooth space. In a motor (1), a stator core (31) comprises of a plurality of divided iron cores (310), a stator (4) has a divided permanent-magnet (420) mounted in the circumferential direction of a revolving shaft (41). In the divided iron cores (310), a gap (38) is formed between the front ends of the adjacent teeth (311), an auxiliary slot (39) is formed on the front end face (313), for dividing the the front end face (313) in the circumferential direction based on a equal angle.

The invention relates to a motor rotor and a method of manufacturing the same. The motor rotor (2000) includes a rotor yoke (250) and a plurality of magnetic pole modules (200) disposed on the rotor yoke (250); each magnetic pole module (200) includes a substrate (210), a case (240) and a pair of magnetic pole units (220, 230) with opposite polarities accommodated in an accommodation space formedby the substrate (210) and the case (240); the magnetic pole units (220, 230) in each magnetic pole module (200) are spaced apart from each other by a first distance along the circumferential direction of the rotor yoke (250); and the plurality of magnetic pole modules (200) are mechanically fixed to the rotor yoke (250) through pressing bars (280) and fasteners ( 270). With the motor rotor of themotor rotor of the invention, generator performance (cogging torque and torque ripple), the protection of the magnetic poles, and the mechanical fixation of the magnetic poles can be shared.

A brushless motor including a toothed part with a tooth main body and a tip part. Protruding slant parts are formed on both sides of the tooth tip part. A tip surface is formed on the inner diameter of the tip part to face a magnet. A groove part is recessed in the center of the tip surface and extends in the axial direction. A depth d of the groove part satisfies 0<d≦(Lx−Rt)/3. A width Wg of the groove part satisfies Wt>Wg≧Wt/2 (Lx: distance between rotor center and a tooth/slant intersection X; X: intersection between an extension line P of a circumferential side surface of the tooth main body and an extension line Q of a slope of the slant part; Rt: radius of the inner diameter of the tooth tip surface; Wt: width of the tooth main body).

The utility model discloses a motor. The number of bulged poles of a stator is twelve, and the number of magnetic poles formed on the peripheral surface of a rotor is ten. The motor not only can form an effective magnetic circuit, but also can reduce the cogging torque. In the motor, the stator (3) disposed at the radial peripheral side of the rotor (2) comprises a stator core (13) which is provided with twelve bulged poles (13a) bulging radially inwards. The rotor (2) comprises a plurality of permanent magnets (8) which are arranged in the peripheral direction in an adjacent manner, and are arranged opposite to tail end faces (13e) of the bulged poles (13a), wherein there are gaps between the permanent magnets (8) and the tail end faces (13e) of the bulged poles (13a). The number of the magnetic poles on the peripheral surface of the rotor (2) is ten. The tail end faces (13e) of the bulged poles (13a) form a concave curved surface through smooth connection surfaces, and surfaces (8b), opposite to the tail end faces (13e) of the bulged poles (13a), of the permanent magnets (8), form a convex curved surface. In the motor, the ratio R1/R2 of the radius R1 of an imaginary circle contacting with a part of surfaces (8b) of the permanent magnets (8) to the curvature radius R2 of each of the surfaces (8b) of the permanent magnets (8) is from 0.4 to 0.55.