用英语解释一下电机的转动原理
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发布时间：2022-04-29 19:58
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热心网友
时间：2022-06-22 05:29
Dc excitation of the magnetic circuit in the electrical equipment, except for the application of dc motor magnets (dc contactor relays, etc), the most important is used in dc motor. In the factory, synchronous generator excitation machine, battery charger, etc, are dc generators, Boiler feed motor is the prime mover. In addition, in many instries, such as large rolling equipment, large precision machine tool, mine hoist, streetcars, cable equipment, strict linear consistent place, usually adopts dc motivation to work as a prime mover, drag the machinery. Dc generator is usually a dc power supply output power; to load, Dc motor is a prime mover drive to work, all proction machines load energy output. In the control system, dc motor and other USES, such as tachogenerators, servo motor, etc. Although dc motor generator and the use of different, but they are basically the same structure, using electric and magnetic energy to realize the interaction with the power switch.
The biggest weakness of dc motor are the current problems, non-ferrous metal, high cost and the maintenance and operation. Therefore, the motor instry is trying to improve the control performance of ac motor, and instead of dc motor. However, in recent years in using thyristor rectifier instead of dc generators, has made great progress. Including dc motor rotate motor, everything is all according to the fact that we know of the two basic principles. A: is the conctor cuts flux proces inction emf, Another: the conctor in electric magnetic field in the role. Therefore, from the structure, including any motor magnetic circuit of the part and. From the above principles, any motor embodies electric and magnetic interaction, electricity and magnetism are the two contradictions in the unity of opposites. In this chapter we discussed in dc motor, the structure and working principle of dc motor is discussed "magnetic" and "electricity" interact each other, and embodies both restricts the relationship between physical phenomena and armature emf, electromagnetic torque, electromagnetic power, the armature reaction, etc.).
一、 直流发电机的基本工作原理
Dc motor generator and has the same structure, just dc generator engine (usually by ac motor rotate and drag.) Visible, it is the mechanical energy into electrical equipment. Dc motor are in the dc power supply, drag on various working machinery (machine, pump, electric cable, equipment, etc.), and it is the job of the mechanical energy into electrical equipment. However, the current SCR rectifier devices have been replaced dc generators, in order to enable us to a better understanding of dc motor, it is necessary to also tells the dc generators.
We first to observe how dc generators.
As shown in figure 1, brush A, B separately with two and A half circle, then contact between two brush A and B is the direct current output. We'll look at the poles movement in between the coil. Figure 1 (a) can see, when the coil ab edge in N a range according to counterclockwise, right, then DingZe application generator generated from the point of the emf. B, Then the CD edge is winding in S very range according to counterclockwise, according to the hand movement DingZe can judge, generators, CD sides of the inced emf direction from d pointing to c. From the perspective of coil, inction emf is d - c - b - a. Therefore, and the connected a copper wire brush is in January and are potentials, Instead of coil and d connected the two and copper brush B is in negative potential. If connected, current/from A load of the brush, brush with coil flows along B closed. Current
When the coil ab edge to S very range, CD edge is transferred to N a range (figure 1, b), with the right to know, when DingZe judgment of coil CD side direction of emf from c to d, and turn into S very ab side within the scope of the emf, which direction is there a to b. Due to the brush in space is motionless, therefore, and the copper wire d connected with brush A contact, 2 it is still the potential. And the copper wire connected a 1 and brush contact, its potential B is still negative. Through/when the current is still A load flow from the brush, brush with coil together constitute B closed current pathways. However, should pay attention to when the current in a coil has been reversed.
Therefore, when the coil constantly rotating, although two brush contact with the coil of change, but the edge, brush A is always are potential, brush B is always A negative potential. Therefore, there are two brush with the direction of the emf is constant, the load is constant direction of voltage and current. That is, while the inction emf in coil abcd alternating direction, but always with A brush in N A range of coil edge contact, brush B always and in S very within the scope of the coil edge contact, their polarity unchanged. Hence, the alternating current copper wire brush after rectifying and pass, become the dc /. These two semicircular copper is called commutation, they together called commutator.
二、 直流电动机的基本工作原理
If the dc motor rotor not drag it, and engine the brush of A and B in the dc power supply voltage U (as figure2shows), then what will happen? From the chart, brush A, B is A potential negative potential, is extremely in N within the scope of the current in the conctor ab from A to B, S A range of conctor of electricity from CD to d c. As I have said before, conctor in electric magnetic field in the role to ab and CD, therefore, two conctors are electromagnetic Fde role. According to the current in the conctor of magnetic field and the direction, DingZe left by motor, the direction of force is ab edge to edge, and CD is right. Because of the magnetic field is uniform, conctor and the same current flows, so, ab edge and CD edge of the same size. So, the coil is received by the electromagnetic force and counterclockwise rotation. When the coil to neutral plane, magnetic coil of current equal to zero, electromagnetic force equal to zero, but because the inertia effect, coil continue rotating. After half turn coil, although in the position with CD ab switched to S, ab edge extremely range, CD edge to N a range, but, owing to the effect of directional and brush, turn to next CD edge N pole in the current direction also changed from d to c, in the very next ab edge "S the current flow from b vitamin. Therefore, the direction of electromagnetic Fdc will remain unchanged, coil still force by turning counterclockwise. Visible, respectively in N, S a range of the current in the conctor is changeless, direction, two side of coil is changeless, such force direction, coil can according to the direction of stress on rotating, through the gear transmission belt agencies or other work, mechanical.
From the above analysis, we can see, to make the coil according to certain direction, the key problem is when the conctor from a pole limits to another opposite poles range (namely conctor through neutral conctor), after the current direction will also change. Commutator and brush is the device to finish the task. In dc generator, the commutator and brush the task was to coil of alternating current to direct current to the output, While in dc motor, then use commutator and brush the input of ac motor into coils. Visible, commutator and dc motor brush is indispensable key components.
Of course, in actual motor, also not only a coil, but there are many a coil of core firmly embedded in the rotor slot, when the conctor in electric fields, by force and in turn, just because of the rotor. This is the basic principle of dc motor.
Dc motor generator and compare the working principle, they could see the input and output of different forms of energy. As has been said before, dc generator engine drive, by the input, output is mechanical energy is, Dc motor is determined by the input dc power supply, power, the output is is energy.
Hope can help you
