RU2362259C1 - Permanent magnet motor - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering, particularly to electrical machines and can be used as a motor in steering wheel boosters of automobiles and low and medium power electric generators. To achieve this outcome, the proposed permanent magnet motor consists of a cylindrical ferromagnetic external rotor, comprising a shaft, a nonmagnetic disc on the shaft and a magnetically conductive cylinder, on the inner surface of which permanent magnets are placed parallel the axis of the rotor. The said motor also has a cylindrical inner stator, placed in line with the rotor. According to this invention, in the magnetic system of the rotor, magnets on the length of each pole are divided into two parts and displaced from each other around the rotor by an angle Δα/2, where Δα=360°/n, where n is the pulse number of magnetic flux in one cycle of the rotor.

EFFECT: easier control of the motor through reduction of tooth ripples of electromagnetic torque.

2 cl, 4 dwg

Description

The invention relates to the field of electrical engineering, in particular to electric machines, and can be used as an engine in power steering cars and electric generators of small and medium power.

A known rotor magnetic system consisting of a package of plates of magnetically conductive steel with holes and prismatic permanent magnets with tangential magnetization NS installed in the holes of the plates at an angle to the radial axis so that the distance between the opposite poles of two adjacent magnets in the outer arc is less than internal, and the holes are made V-shaped, and the magnets installed in them that form the pole division are in contact with the same poles RU 2316103, IPC 7 Н02К 1/27, Н02К 21/14, 2005.07 .fourteen.

This design provides a high value of the magnetic flux in the air gap between the rotor and the stator due to the concentration of the magnetic field of the poles and is highly dependent on changes in the size of the air gap, which makes it necessary to obtain small air gaps, complicates and increases the cost of engine manufacturing technology.

Motors with permanent magnets are known, having an external stator and an internal rotor on which there are permanent magnets described in patents RU 2161852, IPC 7 Н02К 21/14, Н02К 5/132, Н02К 15/04, Н02К 3/04, 1998.03.03 ; RU 2321143, IPC 7 Н02К 21/16, Н02К 1/27, 2005.09.16; RU 2247463, IPC 7 Н02К 21/14, Н02К 1/27, 2002.12.26.

The disadvantage of these motors is that they use an engine design with an internal rotor, which makes it difficult to lay the stator winding and complicates the automation of this process.

The closest in technical essence to the claimed invention is a permanent magnet motor, consisting of a cylindrical ferromagnetic external rotor with permanent magnets located on the inner surface of the rotor parallel to the axis of the rotor, and a stator in the form of a coil with teeth, and the outer surfaces of the stator teeth are opposite the poles of the constant rotor magnets and are separated from each other by an air gap US 2007176505, IPC 7 Н02К 37/14, Н02К 16/02, Н02К 21/12, Н02К 37/12, Н02К 16/00, 2004.02.27.

This design has the positive qualities of magnetic systems with an external rotor, however, it does not solve the problems associated with tooth pulsations of the electromagnetic moment resulting from the uneven distribution of the magnetic flux of permanent magnets due to the presence of a varying air gap due to the stator gearing.

The presence of grooves and teeth of the stator causes an increase in the magnetic resistance of the air gap and uneven induction on the surface of the pole pieces. In places opposite the teeth, induction is greater than in places opposite the grooves.

The design of the engine with an external rotor makes it possible to increase the diameter of the rotor and, therefore, increase the torque and power with the same dimensions.

The problem to which the invention is directed, is to achieve high energy performance magnetoelectric machine while simplifying the manufacturing technology of the engine.

The technical result of the claimed invention is to reduce the pulsation of the pulsation of the electromagnetic moment and, as a result, increase the convenience of controlling the engine.

To achieve a technical result in a permanent magnet electric motor, consisting of a cylindrical ferromagnetic external rotor, including a shaft, a non-magnetic disk located on it and a magnetic conductive cylinder, on the inner surface of which there are permanent magnets parallel to the rotor axis, and a cylindrical internal stator located coaxially with the rotor, according to the invention, in the rotor magnetic system, the magnets are divided into two parts along the length of each pole and are shifted relative to each other around NOSTA rotor by an angle Δα / 2,

where Δα = 360 ° / n,

where n is the number of pulsations of the magnetic flux per revolution of the rotor.

In this case, the magnetically conducting cylinder can be rigidly fixed on one side with the disk and rotor shaft, and with its free cantilever end rely on the supporting surface of the adjacent flange, on which there is a groove filled with grease and in which the elements of the rolling bearing - rolling elements are located.

The proposed permanent magnet motor is shown in figures 1, 2, 3 and 4:

figure 1 is a longitudinal section of an electric motor;

figure 2 - arrangement of permanent magnets in the magnetic system of the rotor;

figure 3 - curve of the moment developed by the engine, taking into account the pulsations of the magnetic moment ± ΔM, superimposed on the average value of the electromagnetic moment Md _o for the engine with an external rotor of conventional design;

figure 4 - curve of the moment as a function of the angle α - the angle of rotation of the rotor in the presence of separation of the poles along the axis of the rotor into two equal parts and when these parts are shifted around the circumference by the angle Δα / 2.

The permanent magnet electric motor consists of an external rotor including a non-magnetic disk 1 and a magnetic cylinder 2, and an internal stator 3. The rotor is made with permanent magnets 4 located on the inner surface of the rotor cylinder 2 and separated by plates 5 of non-magnetic material. The magnetically conducting cylinder 2 rests on the surface of the closing flange 6, which is rigidly fixed to the stator 3. On the flange 6, under the free end of the cylinder 2 there is a groove 7 filled with grease. In the groove of the flange are located simultaneously with the grease the elements of the rolling bearing - rolling elements. The internal stator is made of a burst package, in the grooves of which a winding 8 and a sleeve 9 are laid.

Implementation of the proposed solution.

The rotor poles are formed by permanent magnets 4 with a radial magnetization N-S, located on the inner surface of the rotor cylinder 2, shifted within each pole by an angle Δα / 2 and separated by plates 5 of non-magnetic material, which ensures uniform distribution of the rotor poles around the circumference. Plates of non-magnetic material are used to control the installation of magnets on the inner surface of the rotor cylinder. The magnets are rigidly attached to the inner surface of the rotor, for example with glue, and they are parallel to the axis of the motor coaxially with the motor shaft. The toothed structure of the air gap causes pulsation of magnetic induction. As a result of the presence of grooves and teeth, an uneven rotation of the rotor is obtained, that is, undesirable pulsations of the electromagnetic moment. Separation of magnets into two parts leads to a 2-fold decrease in pulsations from each half of the rotor, and a shift of these parts by an angle Δα / 2 leads to a decrease in the resulting pulsations to zero, since the pulsations of the moment about the rotor part mutually destroy each other, being in antiphase. The number of pulsations of the magnetic flux per revolution of the rotor depends on the ratio of the number of poles of the rotor, the number of stator teeth, the width of the stator teeth. Tails B.C. Electric DC machines. 1988, 336 p., Voldek A.I. Electric cars. The textbook for students of technical schools. 1978, 832 p.

The rotor with its free cantilever end, through a special auxiliary bearing, rests on the supporting surface of the adjacent flange.

To ensure an equal air gap between the rotor magnets and the teeth of the inner stator 3, in the grooves of which the winding 8 and the sleeve 9 are laid, the engine design provides support for the free cantilever end of the cylinder 2 on the surface of the closing flange 6. For this, a flange under the free cantilever end of the cylinder is provided a groove 7 filled with grease, for example Litol-24, which provides the necessary lubrication of rubbing surfaces. In the flange groove, simultaneously with the grease, there are elements of the rolling bearing - rolling elements.

With the same dimensions, the diameter of the working gap in this design of the electric motor is larger, and, therefore, due to the location of the rotor outside the stator, high energy parameters of the magnetoelectric motor are provided with a relatively simple manufacturing technology.

Thus, due to the shift of the rotor permanent magnets by the angle Δα / 2 and the presence of rolling elements with grease in the groove on the flange under the free cantilever end of the cylinder, which is rigidly fixed on the other hand, high energy performance of the magnetoelectric machine is achieved while simplifying the manufacturing technology of the magnetoelectric motor with permanent magnets.

Claims (2)

1. An electric motor with permanent magnets, consisting of a cylindrical ferromagnetic external rotor, including a shaft, a non-magnetic disk located on it and a magnetically conducting cylinder, on the inner surface of which there are permanent magnets parallel to the axis of the rotor, and a cylindrical internal stator located coaxially with the rotor, characterized in that in the rotor’s magnetic system, the magnets along the length of each pole are divided into two parts and shifted relative to each other around the circumference of the rotor by an angle Δα / 2, where Δα = 360 ° / n, where n is the number of pulsations of the magnetic flux per revolution of the rotor. 2. The permanent magnet electric motor according to claim 1, characterized in that the magnetically conducting cylinder is rigidly fixed on one side with the disk and the rotor shaft, and rests on the supporting surface of the adjacent flange with a free cantilever end, on which a groove filled with grease is provided, and which are the elements of the rolling bearing - rolling elements.

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