CN201063509Y - Permanent magnetic DC motor - Google Patents

Abstract

The utility model relates to a permanent-magnet direct current motor provided with a chamfering arched body permanent-magnet shoe and nonisometric commutator segments and belongs to the direct current motor technical field. The utility model adopts the chamfering arched body permanent-magnet shoe; a chamfering surface transversely connected with an arched body is arranged on the angle end of the chamfering arched body permanent-magnet shoe; an arched extrados and an intrados do not have the same circle center. Because the radius of the intrados is larger than that of the extrados, harmonic waves of magnetic field can be effectively reduced, and the distribution of the magnetic field is made to be closer to sine waves, thereby the electromagnetic noise is effectively inhibited. Moreover, the utility model adopts the nonisometric commutator segments, a brush and various commutator segments are made to have different impact cycles and vibration frequencies, and the resonance characteristics of equidistant commutator segments are modified, thereby the vibration and noise of a system are reduced.

Description

Permanent magnet direct current motor

Technical field

The utility model relates to the DC motor technical field, and particularly a kind of have chamfering ogive permanent magnetic tile and some permanent magnet direct current motors that does not wait the sheet commutator segment.

Background technology

Motor extensively and is in large quantities used in every profession and trade production field and family, public place etc., and is closely related with people's work and life.Progress along with society, people have proposed more and more higher requirement and restriction to the noise of contaminated environment, how to reduce motor vibration and noise, reduce influence that noise on human are worked and living environment causes and the harm that health of people is produced thereof, become the problem of needing solution badly.Especially for the motor of air conditioning for automobiles, be to improve driver's comfort level, the noise of motor more there is higher requirement.Consider from desirable point of theory, should not have the sound during motor operation, thereby the motor any sound that sends in service all can be classified as the noise of motor.The general different modes that produces according to electric moter noise can be divided into three major types to its noise substantially: 1. electromagnetic noise; 2. machinery noise; 3. aerodynamic noise.For DC motor, though to reducing and controlling its various noises and taked all prior art measures.But the electric moter noise owing to the influence of complicated actual conditions produces still needs to be suppressed by further technological improvement.

Summary of the invention

The purpose of this utility model is, a kind of permanent magnet direct current motor is provided, and this kind motor can effectively reduce noise.

The purpose of this utility model realizes by following technical solution:

A kind of permanent magnet direct current motor, comprise casing, permanent magnetic tile, brush and commutator, described permanent magnetic tile is fixed on the inner chamber of casing, described commutator comprises commutator segment, it is characterized in that, described permanent magnetic tile profile is the chamfering ogive, have at least the angle end at a place to be provided with the fillet surface that cuts mutually with ogive, fillet surface angle between fillet surface and end face is 30 °～60 °, and its arch extrados radius intrados radius is not the same center of circle, and the intrados radius is greater than the extrados radius.

Described permanent magnet direct current motor is characterized in that, what described commutator comprised 2～5 kinds of different in width does not wait the sheet commutator segment, submits between misphase at the commutator circumference and arranges.

Motor in the running, air gap has an air-gap field between stator and the rotor, the electromagnetic noise of DC motor, mainly be that the harmonic field of air-gap flux field causes to interact to deform and vibrate between the motor each several part and causes, because the existence of teeth groove, produce slot ripples by its influence, their frequency becomes the multiple relation often with magnetic groove number, and harmonic flux has produced the higher noise of frequency.Usually permanent magnetic tile arch extrados and the intrados circular arc that adopts is the same center of circle, integral thickness is basic identical, the approximate trapezoid ripple magnetic field that is produced, the harmonic component of its magnetic potential, to make rotor produce corresponding harmonic torque, become the part of electric electromechanics magnetic torque fluctuation.Owing to the influence of teeth groove has produced the caused vibration and noise of slot ripples, prior art is to adopt the method for skewed slot, it is weakened, and the generation of electromagnetic noise has the reason of various complexity, the inhibition of electromagnetic noise can be set about from many aspects and multiple technologies measure.The utility model adopts chamfering ogive permanent magnetic tile, its angle end is provided with the fillet surface that cuts mutually with ogive, arch extrados and intrados circular arc are not the same center of circle, the intrados radius is greater than the extrados radius, the arch crown part at permanent magnetic tile middle part is thicker, to two side bottoms attenuate gradually, and chamfer configuration is arranged, cause permanent magnetic tile two side bottoms to weaken relatively gradually than the magnetic flux of middle part vault, reduced harmonic field effectively, motor field is distributed more approach sine wave, thereby suppressed electromagnetic noise effectively.

Have in the rotation of brush DC motor, brush and commutator sliding contact, not only produce friction and frictional noise, simultaneously, an insulated trench is all arranged between all commutator segments, because brush clashes into the limit that enters of commutator segment, the periodic bump of brush and commutator segment makes brush produce circular runout in brush carrier and rocks, cause that brush and brush box periodically vibrate, produce brush noise, this noise often comprises a plurality of single-frequency compositions that become multiple with number of segment, has the common convention of brush DC motor to adopt the commutator of equidistant commutator segment, brush has the identical bump cycle with each commutator segment, the frequency (f of its generation _K) be:

$f_K=\mathrm{CK}\frac{n}{60}$

In the formula: C-positive integer (1,2,3,4);

The K-number of segment;

N-rotating speed (r/min).

Said frequencies generally in 10 kilo hertzs, and the commutator distortion, when surface smoothness is bad, noise amplitude will increase.Electromagnetic noise is also relevant with the vibration characteristics (as natural frequency, damping, mechanical impedance and acoustic characteristic etc.) of stator, rotor itself.For example, when exciting force and natural frequency resonance, also can produce very big noise even electromagnetic force is very little.The utility model adopts the commutator segment that does not wait sheet (equidistantly), make brush and each commutator segment that different bump cycle and vibration frequency be arranged, change the resonance characteristics that adopts equidistant commutator segment, thereby reduced the vibration and the noise of system, and proved this effect in practice.

The purpose of this utility model, advantage and characteristics will illustrate by the non-limitative illustration of following preferential embodiment and explain that these embodiment only provide as an example.

Description of drawings

Fig. 1 is the schematic diagram of the special-shaped permanent magnetic tile of the utility model;

Fig. 2 is the vertical view of Fig. 1;

Fig. 3 is that the utility model does not wait pitch of fins commutator schematic diagram;

Fig. 4 is the utility model bearing chamber organigram;

Among the above-mentioned figure, the special-shaped permanent magnetic tile of 1-; The 1a-side; The 1b-bevel edge; 3-holds the limit; The 2-rotor assembly; The 2a-commutator segment; The 2b-armature spindle; The 3-housing; The 4-rolling bearing; The 5-wave washer; The 6-split washer; H-extrados radius and intrados radius vertical range; R-extrados radius; R-intrados radius; α, β, γ-pitch of fins central angle; θ-fillet surface angle.

Embodiment

Embodiment one:

Accompanying drawing 1,2 has been represented the chamfering ogive permanent magnetic tile 1 of present embodiment the two poles of the earth permanent magnet direct current motors.Present embodiment has adopted and different two permanent magnetic tiles 1 of common permanent magnet direct current motor, utilize snap rivet that permanent magnetic tile 1 is riveted on the motor field frame 3 (referring to Fig. 4), and grasp permanent magnetic tile 1 tightly, two permanent magnetic tiles, 1 arch extrados tightly is fitted on the inwall of inner chamber for circular motor field frame 3 symmetrically.As shown in Figure 1, the feature of permanent magnetic tile 1 is that profile is the chamfering ogive, and as shown in Figure 2, there is the fillet surface 1b that cuts mutually with ogive at four jiaos of end places of permanent magnetic tile 1, fillet surface 1b is between end face 1c and base 1a, and the angle between fillet surface 1b and end face 1c (fillet surface angle) θ is 45 °.And the arch extrados radius R of present embodiment permanent magnetic tile 1 and intrados radius r are not the same center of circle, and the vertical range in their centers of circle is h, and the intrados radius is greater than the extrados radius.Permanent magnetic tile 1 produces magnetic flux as the magnetic potential source of motor, and material adopts the gluing neodymium iron boron.The permanent magnetic tile 1 that present embodiment adopts can effectively reduce electromagnetic noise.

Fig. 3 is the structural representation of present embodiment commutator, and it does not wait sheet commutator segment 2a as inserts compression molding in thermoset plastics by 3 kinds, and is staggered alternately on the commutator circumference.The commutator segment 2a of present embodiment adopts 12 altogether, there are 3 kinds not wait width, the pitch of fins central angle of its commutator segment 2a is also unequal, wherein two kinds respectively have 5, pitch of fins central angle alpha and β are respectively 26 ° and 30 °, another kind is 2, and pitch of fins central angle γ is 40 °, and the groove width between the commutator segment 2a of commutator equates.Be the brush that staggers the better periodicity bump identical with commutator segment 2a, present embodiment does not wait the arrangement of sheet commutator segment 2a on the commutator circumference staggered alternate with 3 kinds, and becomes the asymmetric arrangement in commutator shaft center.The convention that changes present embodiment adopt etc. sheet (equidistantly) commutator segment commutator and brush friction, clash into the periodic vibration characteristic that is produced, improved the vibration characteristics that the present embodiment permanent magnet direct current motor is assembled into the air-conditioning system of air blast, the vibration of minimizing system and noise, and also proved this effect in practice.

Again as shown in Figure 4, the supporting of the armature spindle 2b of present embodiment rotor assembly 2 is two rolling bearings 4, and it is fixed in housing 1 bearing chamber.Wave washer 5 is equipped with in the outside at housing 1 bearing chamber rolling bearing 4, gives the suitable precompression in rolling bearing 4 outer rings, so that reduce the play of rolling bearing 4, reduces consequent bearing vibrations noise.The effect of the split washer 6 of rolling bearing 4 inboards is axial endplays of eliminating rotor assembly 2.

The foregoing description is as an illustration example only, is not the qualification that the utility model is done.The utility model can also adopt other modes to implement, for example, can be according to the actual conditions of motor, adjust the size of the fillet surface angle θ between permanent magnetic tile 1 fillet surface 1b and end face 1c, commutator adopts and does not wait sheet commutator segment 2a to can be 2～5 kinds of different in width, the scope of pitch of fins central angle is 20 °～45 °, or the like, do not give unnecessary details one by one at this.All employings are equal to the technical scheme of replacement or equivalent transformation formation, all belong to the protection range of the utility model requirement.

Claims (5)

1. permanent magnet direct current motor, comprise casing, permanent magnetic tile (1), brush and commutator, described permanent magnetic tile (1) is fixed on the inner chamber of casing, described commutator comprises commutator segment (2), it is characterized in that, described permanent magnetic tile (1) profile is the chamfering ogive, have at least the angle end at a place to be provided with the fillet surface (1b) that cuts mutually with ogive, the fillet surface angle (θ) of (1c) is 30 °～60 ° between fillet surface (1b) and end face, its arch extrados radius (R) is not the same center of circle with intrados radius (r), and intrados radius (r) is greater than extrados radius (R).

2. permanent magnet direct current motor according to claim 1 is characterized in that, what described commutator comprised 2～5 kinds of different in width does not wait sheet commutator segment (2), submits between misphase at the commutator circumference and arranges.

3. permanent magnet direct current motor according to claim 2 is characterized in that, it is 20 °～45 ° that described commutator does not wait the scope of sheet commutator segment (2) pitch of fins central angle.

4. according to claim 1,2 or 3 described permanent magnet direct current motors, it is characterized in that, do not wait sheet commutator segment (2) on the commutator circumference, to be the asymmetric arrangement in center.

5. according to claim 1,2 or 3 described permanent magnet direct current motors, it is characterized in that, the supporting of armature spindle (2b) is rolling bearing (4), in the outside of housing (1) bearing chamber rolling bearing (4) wave washer (5) is housed, and split washer (6) is equipped with in rolling bearing (4) inboard.

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