CN103840611A

CN103840611A - Method for prolong service life of permanent magnet direct current motor of automobile fuel pump

Info

Publication number: CN103840611A
Application number: CN201410117340.2A
Authority: CN
Inventors: 杨云飞; 李阳
Original assignee: CHONGQING WANLI LIANXING INDUSTRIAL (GROUP) Co Ltd
Current assignee: CHONGQING WANLI LIANXING INDUSTRIAL (GROUP) Co Ltd
Priority date: 2014-03-27
Filing date: 2014-03-27
Publication date: 2014-06-04

Abstract

The invention discloses a method for prolonging the service life of a permanent magnet direct current motor of an automobile fuel pump. The central line of an electric brush of the motor is deviated from the geometric center line of the motor by 10 degrees to 15 degrees, and the central line of the electric brush rotates in the direction opposite to the rotating direction of the motor. Preferably, the central line of the electric brush is deviated from the geometric center line of the motor by 15 degrees. The work state of the improved motor is stable, voltages and rotating speed are not large in fluctuation, the operating parameter is reasonable, the aims of improving motor reversing, reducing sparks and prolonging the service life are achieved through the method of rotatably moving the position of the center of the electric brush, the problem of large starting inertia is solved, and starting vibration is low. For products produced in a large mass, the method has the advantages of being small in modification, low in cost, extremely easy to achieve and the like.

Description

Increase the method in automobile fuel pump permanent magnet DC motor life-span

Technical field

The present invention relates to a kind of method that increases the automobile fuel pump permanent magnet DC motor life-span.

Background technology

Automobile fuel pump direct current machine comprises stator and rotor, described stator comprises brush, metal shell and is fixed on the permanent-magnet pole of metal shell inwall, and described rotor comprises rotating shaft, rotor core, be fixed in rotating shaft and commutator and the armature winding of brush sliding contact.

At present, the brush of brush motor is all arranged in the geometric center lines of motor, the geometric center lines (geometric center lines is positioned at the pole center line of stator field, and magnetic pole of the stator has several right, and corresponding geometric center lines just has several) that is to say brush center line and the motor of brush overlaps.Can improve like this operating efficiency of motor.

But we know: the feature of permanent magnet DC motor maximum is exactly the commutation of motor, because motor has had commutation, so magneto could rotate.The electromotive force of permanent magnet DC motor armature winding and electric current are alternations, only, by the commutator of rotation and static brush, could between brush, obtain direct voltage and electric current.In the time entering another branch road under the armature loop process brush of rotation, the electric current of this element becomes other direction from a direction, and the conversion of this element current is called commutation.So just can maintain armature normally to a direction rotation.Fig. 1 a, 1b and 1c are motor commutation schematic diagram.Wherein, in Fig. 1 a, produce magnetic pole by winding energising direction, there is a natural attraction between the sexes, and rotor turns clockwise from the center line left side.Fig. 1 b rotor is in the time of center line, and electric current needs commutation, makes winding produce reversed polarity, and two like magnetic poles repel each other, makes rotor continue to turn clockwise.Fig. 1 c, when rotor moves clockwise from center line the right, electric current commutates, and could keep like this operation in the same way.

In the position of Fig. 1 a, the armature of fuel pump motor is simplex lap winding, and A, B end is connected on two two adjacent commutator segments of commutator, and as shown in Figure 2, brush is at the intersection of these two commutator segments.When this position, winding is by short circuit, and is to be placed on pole center by the commutation element of short circuit, and at this moment the induced electromotive force in coil is zero, and its work potential is maximum, the spark minimum of winding.

In the position shown in Fig. 1 b, the electric current of winding must start oppositely to enter B end, and winding polarity is reverse like this, and two S repel extremely mutually, thereby winding continuation is moved in the same way, the commutation position of Here it is winding.This commutation maintains 180 ° of electrical degrees of motor rotation.When after winding Rotate 180 ° electrical degree, must commutate again, continue operation to maintain winding by former rotation direction.Commutation needs the time, and it is relevant with the quantity of motor speed and commutator segment.As fuel pump motor speed 6000r/min, commutator segment number is 8, and be commutating period:

Tk=60/（6000x8）（s）=1.25x10-3（s）

In commutating, the distance that commutation conductor moves past at armature surface is called commutating zone; Electric current in commutation conductor is called the current of commutation.In whole commutation process, the current of commutation is+i～-i, as shown in Figure 3.

Commutation conductor is inductance coil, it is in commutation process, variation in electric current will be followed the variation of magnetic field energy, it postpones commutation, until commutate while end, because armature winding itself is an inductance element, the current of commutation of motor is not according to like that linearly shape commutation of Fig. 3, current of commutation time delay a period of time that the existence of inductance causes commutating conductor.Start inertia large.Also, due to the relation of time delay, unnecessary energy is emitted by force, thereby form the spark under brush, the surface of the commutator of ablation fuel vapor motor.

Summary of the invention

The spark that technical problem to be solved by this invention is to provide a kind of improves commutation, reduce brush and commutator face increases the method for automobile fuel pump electrical machinery life, has solved and has started the large problem of inertia.

Technical scheme of the present invention is as follows: a kind of method that increases the automobile fuel pump permanent magnet DC motor life-span, the brush center line of motor is departed to the geometric center lines 10-15 degree of this motor, and the center line of described brush rotates against motor direction of rotation.

Preferably: the angle that described brush center line departs from motor geometric center lines is 15 degree.

The brush of fuel pump motor, against an angle of motor direction of rotation rotation, to adapt to the electric current of the time delay due to existing of inductance, thereby is reduced to the electric current in commutation loop, improve commutation.So just reduce the spark of brush and commutator face.After improving, can cause decrease in efficiency, electric current to increase, but start steadily, can not shake.Runtime parameter is reasonable, the vehicle fuel pump motor after improving, and due to fuel pump motor one direction operation, generally speaking stable working state, voltage, the fluctuation of speed are little, have solved and have started the large problem of inertia.

Motor after the present invention is improved and the motor before improvement carry out endurance test in 1000 hours, after test, commutator face quality are contrasted.The not commutator face of the fuel pump at the shifting brush center 0.2mm degree of depth (as shown in Figure 4) that has been worn, and commutator face ablation is serious; And the almost not wearing and tearing of the commutator face of the fuel pump motor at brush in rotary moving center, ablated phenomenon (as shown in Figure 5) is also can't see on surface.

Beneficial effect: the electric machine operation state after the present invention improves is stable, voltage, the fluctuation of speed are little, operational factor is reasonable, adopt the method for the position at brush in rotary moving center, reach and improved motor commutation, reduce spark, the object of life-saving, has solved and has started the large problem of inertia, when startup, does not shake.For the product of producing in enormous quantities, this method have change little, cost is low, the advantage such as realization very easily.

Accompanying drawing explanation

Fig. 1 a-1c is motor commutation schematic diagram;

Fig. 2 is brush-commutated position view;

Fig. 3 is the commutation process schematic diagram of the current of commutation;

Fig. 4 is the photo of commutator after the front fuel pump motor test of improvement;

Fig. 5 is the photo after the fuel pump engine commutator test after the present invention improves;

Fig. 6 is structural representation of the present invention.

Embodiment

Below in conjunction with drawings and Examples, the invention will be further described:

Automobile fuel pump direct current machine comprises stator and rotor, and described stator comprises brush 1, metal shell 2 and be fixed on the permanent-magnet pole 3 of metal shell 2 inwalls, and described fuel pump direct current machine is prior art, its structure is not described further at this.Improvements of the present invention as shown in Figure 6, the brush center line A of motor is departed to geometric center lines (pole center line B) the 10-15 degree of this motor, described brush center line A is against the rotation of motor direction of rotation, and the angle that preferably described brush center line A departs from motor geometric center lines is 15 degree.

Claims

1. increase the method in automobile fuel pump permanent magnet DC motor life-span, the brush center line of motor is departed to the geometric center lines 10-15 degree of this motor, described brush center line rotates against motor direction of rotation.

2. the method that increases according to claim 1 the automobile fuel pump permanent magnet DC motor life-span, is characterized in that: the angle that described brush center line departs from motor geometric center lines is 15 degree.