CN201286033Y

CN201286033Y - Motor

Info

Publication number: CN201286033Y
Application number: CN 200820095731
Authority: CN
Inventors: 秦锐锋; 刘清式; 李永斌; 杜成顺; 江远
Original assignee: Johnson Electric Shenzhen Co Ltd
Current assignee: Johnson Electric Shenzhen Co Ltd
Priority date: 2008-07-18
Filing date: 2008-07-18
Publication date: 2009-08-05
Anticipated expiration: 2018-07-18

Abstract

The utility model provides an electric motor comprising a housing, an armature rotatablely arranged in the housing and n permanent magnets fixed in the housing. Wherein the armature comprises a plurality of salient poles extending along the radial direction, the housing comprises n inner convex parts which are positioned between adjacent permanent magnets, the permanent magnets and the inner convex parts are formed into 2n magnetic loops by the housing and the salient poles, n is an integer more than 1. The air gap between the permanent magnets and the armature is more than the air gap between the inner convex parts and the armature.

Description

Motor

[technical field]

The utility model relates to machine field, relates in particular to a kind of miniature permanent magnet DC motor.

[background technology]

Development along with power electronic technology, various motors have obtained using widely in all trades and professions, and wherein permanent magnet DC motor is because simple in structure, and electromagnetic performance is reliable, safeguard simply, be widely used in fields such as office automation, household electrical appliances and car electrics.

As shown in Figure 6, traditional permanent magnet DC motor uses four permanent magnet 101 ~ 104 symmetries to be installed on motor stator iron-clad inboard to produce four field poles usually, also promptly: the number of permanent magnet equals the number of magnetic poles of rotor, from the stator outside, the opposite and common magnetic loop that forms of the pole orientation of adjacent magnets.Yet the motor of this kind structure has following shortcoming:

Be not suitable for the low-power applications occasion that adopts rare-earth magnet.Adopt the low-power applications occasion of rare-earth magnet, in order to make full use of magnet, the requirement that thin usually magnet such as the thickness about 1mm just can satisfy magnetic property, but there is the danger that damages easily in thin magnet in processing and assembling process.If with the magnet thickening, it is insufficient then will to cause magnet to utilize again for the danger that overcomes easy damage, waste magnet.

In each magnetic loop, there is the permanent magnet of two series connection, be easy to generate magnetic saturation, thereby it is insufficient to cause magnet to utilize.

Magnet quantity is more and pole orientation adjacent magnets is opposite, will make assembling process become complicated.

[summary of the invention]

In order to address the above problem, the utility model provides a kind of motor, comprise housing, rotatably be installed in armature in the housing, described armature comprises some salient poles that radially extend, described motor comprises that also n permanent magnet is fixed in the housing inboard, described housing comprises that convex portion is not between adjacent permanent in n, described permanent magnet and interior protuberance form 2n magnetic loop jointly by housing and salient pole, n is the integer greater than 1, and the air gap between described permanent magnet and the salient pole is greater than the air gap between interior protuberance and the salient pole.

The beneficial effect that the utility model illustrated embodiment has is: owing to have only a permanent magnet in each magnetic loop, therefore, magnet of the present utility model can be thicker than magnet of the prior art relatively, thereby can reduce flimsy danger in magnet processing and the assembling process; Owing to have only a permanent magnet in each magnetic loop, thereby can make full use of magnet, be difficult for producing magnetic saturation, reduce ferromagnetic material cost and assembly cost greatly; Because the pole orientation of each magnet is identical, thereby can simplify assembling process and the process that magnetizes; Because the air gap between permanent magnet and the armature is greater than the air gap between interior protuberance and the armature, thereby the asymmetric degree of the back-emf of motor windings be can reduce, thereby the noise and the vibration of motor reduced.

[description of drawings]

Fig. 1 is the motor assembling schematic diagram that the utility model embodiment provides;

Fig. 2 is the rotor and the stator sectional view perpendicular to axial direction of the motor that provides of the utility model embodiment;

Fig. 3 is the magnetic line of force distribution schematic diagram of the motor that provides of the utility model embodiment;

Fig. 4 be the motor that provides of the utility model embodiment air gap evenly with inhomogeneous two kinds of situations under back-emf and the rotor-position of one of them coil under a certain rotating speed concern comparison chart;

Fig. 5 be the motor that provides of the utility model embodiment air gap evenly with inhomogeneous two kinds of situations under the Fourier decomposition comparison chart of the back-emf of one of them coil under a certain rotating speed;

Fig. 6 is the motor of a prior art sectional view perpendicular to axial direction.

[embodiment]

In order to make technical problem to be solved in the utility model, technical scheme and beneficial effect clearer,, the utility model is further elaborated below in conjunction with drawings and Examples.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.

See also Fig. 1 and Fig. 2, according to the motor of the utility model one embodiment comprise housing 20, rotatably be installed in housing 20 inboards armature 40, be installed in inboard and the permanent magnet 60 between housing 20 and armature 40 of housing 20, and be fixed in the end cap 80 of housing 20 1 ends.

Described housing 20 is made by permeability magnetic material usually, is roughly cylindricly, and it is outstanding inwardly away from both sides of end cap 80 parts, thereby forms protuberances 22 in two, described in protuberance 22 can be by inside punching press of the counterpart of housing 20 or stretching be formed.

Described armature 40 rotatably is installed in the inboard of housing 20 by rotating shaft 90, described armature 40 comprise some along motor shaft to the laminated core that laminates, thereby described laminated core is radially slotted and is formed some salient poles 42, so as to flow through the enamelled wire of electric current can pass the fluting and be wound on the salient pole 42.

Described two permanent magnets 60 can be individually fixed between the two interior protuberances 22 of described housing 20 inboards by industry mode commonly used.Along rotor radial, the air gap that magnet 60 and armature are 40 is air gap I, and the air gap that two interior protuberances 22 of described housing 20 and armature are 40 is air gap II, and the size of air gap I is greater than air gap II.Alternatively, the polar arc angle [alpha] of permanent magnet 60 parts is greater than the polar arc angle beta of interior convex portion 22.The inner surface of described permanent magnet 60 is towards salient pole, outer surface is fixed to housing 20, alternatively, described inner surface and outer surface are nonconcentric(al) arc, the thickness of the mid portion of permanent magnet 60 is greater than the thickness of two end portions, thereby makes air gap between mid portion and the armature salient pole less than the air gap between two end portions and the armature salient pole.

See also Fig. 3, in embodiment of the present utility model, two magnet 60 can produce four magnetic poles, that is: two magnet 60 itself each self-forming field pole (field pole), as the two N utmost points among Fig. 2, housing 20 two in protuberance 22 places produce respectively the induction magnetic pole (induced field pole), as the two S utmost points among Fig. 2, each field pole and the two adjacent induced magnetism utmost points form magnetic loop by the salient pole 42 of armature 40, like this, in each magnetic loop, have only a permanent magnet, thereby can make full use of magnet.

Fig. 4 be the motor that provides of the utility model embodiment air gap evenly with inhomogeneous two kinds of situations under back-emf and the rotor-position of one of them coil under a certain rotating speed concern comparison chart; Fig. 5 be the motor that provides of the utility model embodiment air gap evenly with inhomogeneous two kinds of situations under the Fourier decomposition comparison chart of the back-emf of one of them coil under a certain rotating speed.

See also Fig. 4 and Fig. 5, the counter potential waveform the when counter potential waveform the when dotted line among Fig. 4 represents air gap even, solid line are represented air gap I greater than air gap II.As can be seen, when air gap was even, the asymmetric situation of counter potential waveform was more serious, showed that the content of even-order harmonic in its Fourier decomposition is higher; And as air gap I during greater than air gap II, can reduce the asymmetric of back-emf, thereby reduce even harmonic content.

In embodiment of the present utility model, owing to have only a permanent magnet in each magnetic loop, therefore, magnet of the present utility model can be thicker than magnet of the prior art relatively, thereby can reduce flimsy danger in magnet processing and the assembling process; Owing to have only a permanent magnet in each magnetic loop, thereby can make full use of magnet, be difficult for producing magnetic saturation, reduce ferromagnetic material cost and assembly cost greatly; Because the pole orientation of each magnet is identical, thereby can simplify assembling process and the process that magnetizes; Because the air gap between permanent magnet and the armature is greater than the air gap between interior protuberance and the armature, thereby can reduce to result from the asymmetric degree of the back-emf on the electric machine winding, the polar arc angle of permanent magnet part also helps to reduce the asymmetric degree of back-emf, the noise and the vibrations that reduce to help reducing motor of the asymmetric degree of back-emf greater than the polar arc angle of interior convex portion.

The above only is preferred embodiment of the present utility model; not in order to restriction the utility model; all any modifications of within spirit of the present utility model and principle, being done, be equal to and replace and improvement etc., all should be included within the protection range of the present utility model.

Claims

1, a kind of motor, comprise housing, rotatably be installed in armature in the housing, described armature comprises some salient poles that radially extend, it is characterized in that: described motor comprises that also n permanent magnet is fixed in the housing inboard, described housing comprises that convex portion is not between adjacent permanent in n, described permanent magnet and interior protuberance form 2n magnetic loop jointly by housing and salient pole, n is the integer greater than 1, and the air gap between described permanent magnet and the armature is greater than the air gap between interior protuberance and the armature.

2, motor as claimed in claim 1 is characterized in that: described motor is a permanent magnet DC motor.

3, motor as claimed in claim 2 is characterized in that: described permanent magnet DC motor forms four magnetic poles jointly by protuberance in two permanent magnets and two.

4, as each described motor of claim 1 to 3, it is characterized in that: the polar arc angle of described permanent magnet part is greater than the polar arc angle of interior convex portion.

5, motor as claimed in claim 4 is characterized in that: the inner surface of described permanent magnet is towards salient pole, and outer surface is fixed to housing, and described inner surface and outer surface are nonconcentric(al) arc.

6, motor as claimed in claim 5 is characterized in that: the thickness of the mid portion of described permanent magnet is greater than the thickness of two end portions, thereby makes air gap between mid portion and the armature less than the air gap between two end portions and the armature.

7, motor as claimed in claim 1 is characterized in that: described housing is a uniform thickness, and described interior protuberance is by forming inside punching press of the counterpart of housing or stretching.