CN101414774B

CN101414774B - Brushless DC motor

Info

Publication number: CN101414774B
Application number: CN200810213024XA
Authority: CN
Inventors: 金洪正
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2007-08-21
Filing date: 2008-08-20
Publication date: 2012-08-22
Anticipated expiration: 2028-08-20
Also published as: JP2009050138A; CN101414774A; KR20090019627A

Abstract

The invention discloses a brushless DC motor. According to the invention, the distortions of the maximum and minimum of the induction voltage can be prevented, therefore the performance of the motor can be improved. The brushless DC motor provided by the invention, comprises a stator forming multiple grooves and teeth, a rotator core arranged in the stator and forming a magnet embedding hole and a magnetic leak-proof hole, and a permanent magnet arranged in the magnet embedding hole, wherein the magnetic leak-proof hole is provided a hole curved from the periphery of the magnetic leak-proof hole to the inside of the rotator core along with the periphery of the rotator core and the periphery of the magnetic leak-proof hole separated from the periphery of the rotator core.

Description

Brshless DC motor

Technical field

The present invention relates to a kind of brshless DC motor, relate in particular to anti-leakage field pore structure is carried out improved brshless DC motor.

Background technology

In general, drive unit is widely used in producing the industrial circle of home appliance and industrial equipment etc.In this drive unit, representative is to utilize power-actuated motor.

Motor is divided into a variety of according to its application target.Brshless DC motor wherein (BrushlessDirect Current Motor) especially has following characteristics: do not have mechanical contact portions such as commutator and brush, can reduce volume and weight, can be easy to control rate.Thus, not only prevent electric mill and undermine mechanical wear and noise, and compare with motor and to have longer useful life relatively, thereby its scope of application just progressively enlarges with brush.

Existing brshless DC motor comprises: stator; Be arranged on the rotor core that magnet is imbedded the hole that is formed with of stator inboard; Be embedded to magnet and imbed the permanent magnet in hole; Be riveted to the top and the bottom cover plate of two sides of rotor core.

But prior art exists for and prevents the leakage field phenomenon that takes place on the permanent magnet and be formed on magnet to imbed the problem that the anti-leakage field hole at two ends, hole can't prevent leakage field effectively.

Summary of the invention

The present invention proposes in order to address the above problem, and the object of the present invention is to provide a kind of brshless DC motor of the distortion phenomenon that can prevent partly to occur in the maximum of induced voltage part and minimum value.

And, another object of the present invention is to provide a kind of brshless DC motor that can improve motor performance and be easy to control.

To achieve these goals; Brshless DC motor provided by the present invention; Comprise the stator that is formed with a plurality of grooves and tooth (teeth), be arranged on the inboard magnet that is formed with of said stator and imbed the rotor core in hole and anti-leakage field hole and be arranged on the permanent magnet that said magnet is imbedded the hole; It is characterized in that: said anti-leakage field hole has the anti-leakage field hole outer peripheral edges that separate along said rotor core outer peripheral edges and said rotor core outer peripheral edges, and forms from said anti-leakage field hole outer peripheral edges to the bent hole of said rotor core interior curve.

Preferably; Said anti-leakage field hole further comprises the leak main body that is connected with said bent hole, and said bent hole comprises: be connected with a side end of said leak main body and outer peripheral edges begin the bend to said rotor core interior curve from said anti-leakage field hole; From the rake of said bend to said rotor core inner inclination extension; Form the terminal end of said rake.

Preferably, said bend is imbedded the center position bending in hole to said magnet.

Preferably, said bent hole is imbedded straight line that center, hole and said rotor core center be linked to be about said magnet and other adjacent bent holes are arranged in opposite directions.

Preferably; Said end is arranged between first jiao and second jiao; Wherein, Said first jiao is made up of the outside end of said rotor core center with a plurality of adjacent teeth of the number of teeth X that is equivalent to confirm according to following formula, and said second jiao by to the said first jiao outside adjacent a pair of groove carry out binary line and constitute, the formula that is used for definite said number of teeth X is:

Total groove number of number of teeth X=stator/(rotor number of poles * power supply number).

Preferably, the terminal point that meets of said rake and said end is arranged in the extended line of said anti-leakage field hole outer peripheral edges and constitutes point that said first jiao straight line meets and be parallel to said magnet from said bend and imbeds between the line that the length direction in cross section, hole extends.

Preferably, the bend of said bent hole be arranged in said second jiao and prolong from said rotor core center and to the said second jiao outside adjacent a pair of tooth carry out between the triangle that binary line constituted.

Preferably, said magnet is imbedded the hole and is had the rectangle cross sectional shape, and is the form of twisted rotary shaft with the state arrangement that each magnet is imbedded the end certain distance disconnected from each other in hole.

Preferably, the width of the width of the said rake said leak main body that equals to be connected with said rake.

According to the present invention, can prevent the distortion phenomenon that partly occurs in the maximum of induced voltage part and minimum value, thereby improve motor performance.

And, can improve the controllability of motor, thereby can improve reliability of products.

Description of drawings

Fig. 1 is the sectional view according to the brshless DC motor of exemplary embodiment of the present invention;

The sectional view that Fig. 2 amplifies for the bent hole to Fig. 1;

The sectional view that Fig. 3 amplifies for the rake to Fig. 2;

Fig. 4 A is the magnetic flux flow cardon of expression according to the magnetic flux flows of the brshless DC motor of prior art;

Fig. 4 B is the magnetic flux flows line chart of magnetic flux flows at the stator tooth place of presentation graphs 4A;

Fig. 4 C is the induced voltage line chart with the magnetic flux flows of induced voltage presentation graphs 4B;

The line chart that Fig. 4 D changes for the expression induced voltage corresponding with the magnetic flux flows of Fig. 4 A;

Fig. 5 A is the magnetic flux flow cardon of expression according to the magnetic flux flows of brshless DC motor of the present invention;

Fig. 5 B is the synoptic diagram that is used for according to the magnetic flux flows at the stator tooth place of the rotation key diagram 5A of rotor;

Fig. 5 C is the synoptic diagram that is used for according to the magnetic flux flows at the stator tooth place of the rotation key diagram 5A of rotor;

Fig. 5 D is the line chart corresponding to the magnetic flux flows of the rotation of rotor core at stator tooth place shown in presentation graphs 5B and Fig. 5 C;

Fig. 5 E is the line chart with the magnetic flux flows of the change list diagrammatic sketch 5D of induced voltage;

The line chart that Fig. 5 F changes for the expression induced voltage corresponding with the magnetic flux flows of Fig. 5 A.

Main symbol description: 100 is brshless DC motor, and 110 is stator, and 111 is yoke, and 113 is groove, and T is a tooth; 117 is coil, and 120 is rotor core, and 121 imbed the hole for magnet, and 123 is permanent magnet; 125 are rotating shaft, and 140 are anti-leakage field hole, and 141 is the leak main body, and 143 are anti-leakage field hole outer peripheral edges; 150 is bent hole, and 151 is bend, and 153 is rake, and 155 is the end.

Embodiment

Below, specify the present invention with reference to accompanying drawing.

Fig. 1 representes the sectional view of brshless DC motor schematic configuration according to an exemplary embodiment of the present invention, the sectional view that Fig. 2 partly amplifies for the bent hole to Fig. 1, the sectional view that Fig. 3 amplifies for the rake to Fig. 2.

Brshless DC motor 100 provided by the present invention comprises stator 110, rotor core 120, anti-leakage field hole 140 and bent hole 150.

As shown in Figure 1, roughly form drum according to the stator 110 that exemplary embodiment provided through range upon range of magnetic steel plate.Stator 110 is formed with a plurality of grooves 113.Stator 110 further comprises yoke 111, tooth T and coil 117.

As shown in Figure 1, yoke 111 forms the profile that comprises outer peripheral edges of stator 110, and it is formed by the magnetic steel plate stack, has drum.

As shown in Figure 1, groove 113 is used to hold coil 117 for to be formed on the space between each tooth T.

Like Fig. 1 and shown in Figure 2, tooth T has from yoke 111 to radially inner side, the shape of promptly extending to rotor core 120 center O.

Below, for the symbol of tooth T, can be expressed as the first tooth T as required ₁, the second tooth T ₂Deng distinguishing or unified represent with T.

As shown in Figure 1, coil 117 is accommodated in the groove 113, and forms magnetic field through interacting with permanent magnet 123, thereby induction produces magnetic flux flows.

As shown in Figure 1, have a determining deviation between rotor core 120 and the stator 110, and rotor core 120 to be set to relative stator 110 rotatable.As stator 110, rotor core 120 is also formed by a plurality of magnetic steel plate stack, cylindrical shape.Rotor core 120 comprises magnet and imbeds hole 121, permanent magnet 123 and rotating shaft 125.

As shown in Figure 1, along the circumferential direction form a plurality of magnet in the outside of rotor core 120 central parts and imbed hole 121.Magnet is imbedded and is accommodated the permanent magnet 123 that can produce magnetic flux in the hole 121.

Magnet is imbedded hole 121 and is had the rectangle cross sectional shape, and the best state arrangement of imbedding the end certain distance disconnected from each other in hole 121 with each magnet is the form around said rotating shaft 125.

As shown in Figure 1, rotating shaft 125 is pressed into rotor core 120 centers, rotates jointly with rotor core 120.

Rivet hole 127 is located at that magnet is imbedded 121 outsides, hole and mutually combine a plurality of tops cover plate and bottom cover plate (not shown), imbeds hole 121 from magnet and spins off to prevent permanent magnet 123.

Anti-leakage field hole 140 is located at magnet and imbeds the zone between the hole 121, can prevent the leakage of magnetic flux that permanent magnet 123 is produced.

At this, property embodiment is as shown in Figure 1 as an example, and the line that

anti-leakage field hole

140a, 140b imbed hole 121 central authorities and rotor core 120 center O about magnet is arranged as two pairs symmetrically.That is, a pair of anti-leakage field hole 140a and rotor core 120 center O arranged adjacent, and have the triangular-section, and a pair of anti-leakage field hole 140b is arranged in the outside that leakage field hole 140a is prevented in the triangular-section in addition, roughly is the L shape.Below, only the anti-leakage field hole 140b that roughly is the L shape is described about anti-leakage field hole 140.But anti-leakage field hole 140 can have the multiple shape that is different from exemplary embodiment.Below, for the symbol in the anti-leakage field hole 140 of representative, when not distinguishing especially, unification is represented with symbol 140.

The bent hole 150 that anti-leakage field hole 140 comprises the leak main body 141 of L shape and is connected with a side end of leak main body 141, outer peripheral edges 143 are extended towards rotor core 120 inner inclination ground from anti-leakage field hole.

At this, anti-leakage field hole outer peripheral edges 143 are the exterior lateral area in anti-leakage field hole 140, keep at a certain distance away with the outer peripheral edges of rotor core 120.

Bent hole 150 is connected with the end that outer peripheral edges 143 are provided with along anti-leakage field hole of leak main body 141.Bent hole 150 is from preventing that leakage field hole outer peripheral edges are towards rotor core 120 interior curve.Bent hole 150 comprises bend 151, rake 153 and end 155.

Bent hole 150 imbeds the line of 121 centers, hole and rotor core 120 center O about magnet and adjacent bent hole 150 is arranged in opposite directions.That is, as shown in Figure 2, the line that bent hole 150 is imbedded 121 centers, hole and rotor core 120 centers about magnet is (referring to the O-O of Fig. 2 ₁Line) arranges in opposite directions with another adjacent bent hole 150.That is, a bent hole 150 is about O-O ₁Line and another adjacent bent hole 150 symmetric arrangement.

Thus, the distortion phenomenon that utilizes bent hole 150 prevention partly to occur in the maximum part and the minimum value of induced voltage, thus can improve motor properties.And, can improve the controllability of motor, thereby can improve reliability of products.

First jiao of A is that the outboard end of rotor core 120 center O and a plurality of adjacent tooth that is equivalent to number of teeth X is (referring to the O-O of Fig. 2 and Fig. 3 ₂Line) angle that is constituted.That is, as shown in Figure 2, first jiao of A is the first tooth T that is equivalent to number of teeth X ₁, the second tooth T ₂The angle that constituted of outside end and rotor core 120 center O.

Second jiao of B be prolong from rotor core 120 centers and to the outside of first jiao of A adjacent a pair of groove 113 carry out binary line (referring to the O-O of Fig. 2 and Fig. 3 ₃Line) angle that is constituted.That is, as shown in Figure 2, second jiao of B is tooth T ₁, T ₃Between intermediate point, tooth T ₂, T ₄Between the angle that constituted of intermediate point and rotor core 120 center O.

Triangle C be prolong from rotor core 120 centers and to the outside of second jiao of B adjacent a pair of tooth T carry out binary line (referring to the O-O of Fig. 2 and Fig. 3 ₄Line) angle that is constituted.That is, as shown in Figure 2, triangle C be from rotor core 120 center O prolong and to the outside of second jiao of B adjacent a pair of tooth (be T ₃, T ₄) carry out the angle that binary line constituted.

Bend 151 is zones that outer peripheral edges 143 begin to rotor core 120 interior curve from anti-leakage field hole.The center position that bend 151 is imbedded hole 121 to magnet is crooked.Bend 151 is formed between second jiao of B and the triangle C.

Rake 153 is from the zone of bend 151 to rotor core 120 inner inclination.Rake 153 preferably has impartial width.But rake 153 is to prevent that flux leakage from being can take width that multiple shapes such as a little variation take place in the scope of purpose.One side of rake 153 is connected with bend 151, and its opposite side then forms end 155.

At this, the width of bend 151 and rake 153 is preferably identical with the width of leak main body 141.

End 155 is formed between first jiao of A and the second jiao of B.

And, as shown in Figure 3, the terminal point P that meets in rake 153 and end 155 ₁Be arranged in a P ₂With straight line L ₁Between, its mid point P ₂Be anti-leakage field hole outer peripheral edges 143 extended line with constitute the point that nearer straight line meets in two straight lines of first jiao, straight line L ₁Be to be parallel to magnet from bend 151 to imbed the line (referring to the height H of Fig. 3) that the length direction in 121 cross sections, hole extends.

The quantity of applied tooth T (number of teeth) X among the present invention confirms according to following formula (1).

Total groove number of number of teeth X=stator/(rotor number of poles * power supply number) (1)

Below, with reference to Fig. 1 exemplary embodiment of the present invention is described.When the groove number of stator is 24, the number of poles of rotor is 4 utmost points, and the power supply number is 3 phase times, and the number of teeth X that is obtained by formula (1) is 24/ (4 * 3)=2.Down in the face of the number of teeth is that 2 situation describes, but the quantity of tooth T can change according to the quantity of the groove 113 that forms on the stator 110 etc.

The course of work according to brshless DC motor 100 of the present invention with said structure is following.

At first, for making brshless DC motor 100 work, to coil 117 making current of a plurality of grooves 113 that are wrapped in stator 110, thereby the polarity of each coil 117 changes successively.Thus, when producing repulsion when identical with coil 117 formed polarity corresponding to the polarity of each permanent magnet 123 of each coil 117, and when polarity is opposite the generation attraction.Has rotary driving force when thus, rotor core 120 is with rotating shaft 125 common rotations.

For this process is described, the brshless DC motor 100 (with reference to Fig. 4 A to Fig. 4 D) and the brshless DC motor of the present invention 100 (with reference to Fig. 5 A to Fig. 5 F) of prior art compared explanation as follows.

At first, Fig. 5 A is the figure of expression according to the magnetic flux flows of brshless DC motor 100 of the present invention; Fig. 5 B and Fig. 5 C are used to explain the tooth T place at the stator 110 of Fig. 5 A, the synoptic diagram that the magnetic flux flows corresponding with the rotation of rotor core 120 changes.Fig. 5 D and Fig. 5 E are the magnetic flux flow cardon of the corresponding magnetic flux flows situation of the rotation with rotor core 120 at tooth T place of stator 110 shown in presentation graphs 5B and Fig. 5 C.Fig. 5 F is the induced voltage sketch map that the induced voltage of presentation graphs 5A changes.

At this,, suppose and the first tooth T to Fig. 5 A ₁Twine U phase coil 117 in the adjacent grooves 113, with the 5th tooth T ₅Twine V phase coil 117 in the adjacent grooves 113, with the 4th tooth T ₄Twine W phase coil 117 in the adjacent grooves 113.Below, only consider the flux change that is produced by U phase coil 117 and permanent magnet 123 and describe.

Shown in Fig. 5 A, there are differences according to the magnetic flux flows shown in magnetic flux flows of the present invention and Fig. 4 A according to prior art.Below, this is elaborated.

When rotor core 120 is positioned at the position shown in Fig. 5 A, the first tooth T ₁The magnetic flux at place is maximum, the 5th tooth T ₅The magnetic flux at place is minimum, and the second tooth T ₂And the 3rd tooth T ₃The magnetic flux at place is less than the first tooth T ₁

That is, shown in Fig. 5 B, at rake 153 outsides and the 5th tooth T ₅Between (referring to the K of Fig. 5 B ₁) form magnetic flux hardly.That is the 5th tooth T, ₅Between end and the anti-leakage field hole outer peripheral edges 143 at certain intervals each other near.Thereby, at the 5th tooth T ₅And between the leak main body 141 in anti-leakage field hole 140, minimum by U phase coil 117 with permanent magnet 123 formed magnetic flux.

Shown in Fig. 5 C, rotor core 120 rotates by counter clockwise direction with respect to stator 110.

Thus, according to rotating counterclockwise of rotor core 120, the 3rd tooth T ₃The magnetic flux at place increases by sinusoidal rule, the first tooth T ₁And the second tooth T ₂The magnetic flux at place reduces by sinusoidal rule gradually.

And, the 5th tooth T ₅And form predetermined path between the rake 153 (referring to the K of Fig. 5 C ₂).That is the 5th tooth T, ₅Form predetermined interval K through rake 153 between end and the anti-leakage field hole outer peripheral edges 143 ₂, and through having the K of predetermined space ₂The zone forms the path that magnetic flux is passed through.That is, through according to rake 153 formed with the 5th tooth T ₅Interval K ₂, along permanent magnet 123 and the 5th tooth T ₅Between magnetic flux flows is arranged.

Observation is carried out the variation of the induced voltage of differential to this flux change amount, then the first tooth T ₁The U phase induced voltage at place is zero, along with rotor core 120 becomes minimum value by counterclockwise rotating U phase induced voltage from zero.On the other hand, the 5th tooth T ₅The U phase induced voltage at place is along with magnetic flux is started from scratch by sinusoidal rule increase from the maximum vanishing.

That is, by U at the 5th tooth T ₅The induced voltage that the place produces is shown as the curve that how much has sinusoidal rule shown in Fig. 5 E.But curve is linearly over time for the induced voltage that Fig. 4 C representes.This is because do not adopt rake 153 of the present invention in the prior art.

At this, has the following relation that is called faraday's rule between induced voltage and the total magnetic flux.

Induced voltage=d (total magnetic flux)/dt

That is, for instance, when total magnetic flux is when having sinusoidal wave function or the cosine wave function of sinusoidal rule, because its differential value equals induced voltage, so the function curve of induced voltage and total magnetic flux has 90 phase differences of spending.

More than, with reference to Fig. 5 B to Fig. 5 C the 5th tooth T among a plurality of tooth T has been described ₅The variation that the magnetic flux at place and induced voltage take place corresponding to the trickle rotation of rotor core 120.

If intactly represent the variation of this induced voltage, then shown in Fig. 5 F.That is, bent hole 150 provided by the present invention makes the induced voltage curve approaching more sinusoidal wave compared with prior art at the maximum and the minimum value place of induced voltage.That is, can prevent shown in Fig. 4 D, to occur in the maximum of induced voltage and the distortion phenomenon at minimum value place.

Thus, brshless DC motor provided by the present invention can prevent and slow down the distortion phenomenon of the maximum part or the minimum value part of induced voltage, thereby can improve motor performance.And, because therefore the variation of induced voltage can improve the control ability of motor more near sinusoidal wave.

Claims

1. brshless DC motor comprises the stator that is formed with a plurality of grooves and tooth, is arranged on the inboard of said stator and is formed with magnet and imbed the rotor core in hole and anti-leakage field hole and be arranged on the permanent magnet that said magnet is imbedded the hole, it is characterized in that:

Said anti-leakage field hole has along the anti-leakage field hole outer peripheral edges that the outer peripheral edges of the outer peripheral edges of said rotor core and said rotor core separate, and forms from said anti-leakage field hole outer peripheral edges to the bent hole of said rotor core interior curve;

Said anti-leakage field hole further comprises the leak main body that is connected with said bent hole, and said bent hole comprises: be connected with a side end of said leak main body and outer peripheral edges begin the bend to said rotor core interior curve from said anti-leakage field hole; From the rake of said bend to said rotor core inner inclination extension; Form the terminal end of said rake;

Said end is arranged between first jiao and second jiao; Wherein, Said first jiao is made up of the outside end of said rotor core center with a plurality of adjacent teeth of the number of teeth X that is equivalent to confirm according to following formula; And said second jiao by to the said first jiao outside adjacent a pair of groove carry out binary line and constitute, be used for confirming that the formula of said number of teeth X is:

Total groove number of number of teeth X=stator/(the rotor number of poles * power supply number of phases).

2. brshless DC motor according to claim 1 is characterized in that the center position that said bend imbeds the hole to said magnet is crooked.

3. brshless DC motor according to claim 1 is characterized in that said bent hole is imbedded straight line that center, hole and said rotor core center be linked to be about said magnet and other adjacent bent holes are arranged in opposite directions.

4. brshless DC motor according to claim 1 is characterized in that the terminal point that meets in said rake and said end is arranged in the extended line of said anti-leakage field hole outer peripheral edges and constitutes nearer straight line meets in two said first jiao straight lines point and be parallel to said magnet from said bend to imbed between the line that the length direction in cross section, hole extends.

5. brshless DC motor according to claim 1, the bend that it is characterized in that said bent hole be arranged in said second jiao and prolong from said rotor core center and to the said second jiao outside adjacent a pair of tooth carry out between the triangle that binary line constituted.

6. according to claim 1 or 5 described brshless DC motors, it is characterized in that said magnet imbeds the hole and have the rectangle cross sectional shape, and be the form of twisted rotary shaft with the state arrangement that each magnet is imbedded the end certain distance disconnected from each other in hole.

7. the width of the said leak main body that brshless DC motor according to claim 1, the width that it is characterized in that said rake equal to be connected with said rake.