CN2681438Y

CN2681438Y - Permanent-magnet DC motor with AC power supply

Info

Publication number: CN2681438Y
Application number: CNU2004200029016U
Authority: CN
Inventors: 许晓华; 马巧芬; 张巧巧
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-01-15
Filing date: 2004-01-15
Publication date: 2005-02-23
Anticipated expiration: 2014-01-15

Abstract

The utility model discloses a permanent-magnet DC motor with AC power supply, comprising a permanent-magnet DC motor, which is characterized in that the permanent-magnet DC motor with AC power supply is also provided with a front end circuit which is used for filtering and current rectification . The front end circuit can rectify an AC power supply into a DC power supply, a filter circuit can make the voltage of the both ends of the armature keep stable, which makes the permanent-magnet DC motor be directly applied in alternating current environment. The improved motor not only inherits the advantages of permanent-magnetic DC motor of simple structure, low cost, convenient speed governing, stable operation and low noise, etc. but also can be applied on occasions of alternating current power supply, which widens the application field of the DC motor. Simultaneously, the utility model can be improved form the existing DC motor products, needing no designs of novel products and saving expenses of research.

Description

The permanent magnet DC motor of Alternating Current Power Supply

Technical field

The utility model relates to machine field, specifically a kind of permanent magnet DC motor of Alternating Current Power Supply.

Background technology

Permanent magnet DC motor is owing to advantages such as it is simple in structure, cheap, speed governing is convenient and noise is low are widely used.Existing DC is made of front end housing, casing, magnet steel, rotor, commutator and rear end cap with carbon brush structure, its operation principle is: when coil electricity, its effective edge is in a utmost point of magnet steel, the N utmost point for example, this effective edge will be subjected to the effect of an electromagnetic force this moment, under the effect of this electromagnetic force, rotor will produce rotation; When rotor rotates to another utmost point that this effective edge is in magnet steel, when being the S utmost point, because the effect of cooperatively interacting between the commutator of motion and the static carbon brush, the flow through current opposite in direction of this effective edge, this moment is because the direction in magnetic field is also just in time opposite, make the electromagnetic force that acts on this effective edge keep identical direction, rotor continues rotation; When this effective edge rotated to the next N utmost point, the electric current of this effective edge of flowing through was commutated once more, and the direction that acts on electromagnetic force on this effective edge and electromagnetic torque like this remains constant, and motor is rotated continuously.

From above analysis as can be known, existing permanent magnet DC motor only is adapted at work under the dc state.But along with improving constantly and scientific and technical continuous development of people's living standard, the application of motor is also constantly enlarging, and especially micro-machine is widely used in industries such as household electrical appliance and auto industry.Owing to have only Alternating Current Power Supply in a lot of occasions, thereby limited the application of direct current machine.

Summary of the invention

To be solved in the utility model is the problem that existing permanent magnet DC motor can't be used in communication environment, the technical scheme that addresses the above problem employing is: the permanent magnet DC motor of Alternating Current Power Supply, comprise this machine of permanent magnet DC motor, it is characterized in that also being provided with the front end circuit of a rectifying and wave-filtering.Because this front end circuit can be DC power supply with the AC power rectification, and make the voltage held stationary at armature two ends, make this permanent direct-current electric function directly be applied in the communication environment through filter circuit.Motor after the improvement, promptly kept simple in structure, cheap, the speed governing of permanent magnet DC motor convenient, running steadily and advantage such as noise is low, can apply to the occasion of Alternating Current Power Supply again, widen the application of direct current machine greatly, have wide commercial use and economic outlook.Simultaneously, can also utilize existing direct current machine product directly to improve, need not design new product line separately, can save development costs.

Described current rectifying and wave filtering circuit can adopt conventional any type of current rectifying and wave filtering circuit.Under the prerequisite that satisfies the motor performance requirement, simple as far as possible for making circuit structure, and to reduce product cost and machine volume to greatest extent, the preferred bridge rectifier of described rectification circuit.Described filter circuit comprises a pair of inductance and a pair of ground capacity, and described a pair of inductance is connected between the output and motor windings of rectification circuit, and an end of described ground capacity is connected on the output of described rectification circuit.The output of described rectification circuit a pair of fly-wheel diode in parallel.For making complete machine structure more compact, described current rectifying and wave filtering circuit is arranged on the rear end cap of motor.

Description of drawings

The utility model is described in further detail below in conjunction with drawings and Examples.

Fig. 1 is a structural representation of the present utility model.

Fig. 2 is the electrical schematic diagram of front end circuit.

Fig. 3 is the oscillogram of alternating voltage.

Fig. 4 is the voltage oscillogram after full-wave rectification.

Fig. 5 is through filtered voltage oscillogram.

Embodiment

In embodiment illustrated in fig. 1, the body of permanent magnet DC motor comprises front end housing 4, casing 3, magnet steel 7, rotor 8, commutator 2 and has the rear end cap 5 of carbon brush structure 6, be provided with the front end circuit plate 1 of a rectifying and wave-filtering on described rear end cap 5.

With reference to Fig. 2, described rectification circuit I adopts bridge rectifier.Described filter circuit comprises a pair of inductance L 1, L2 and a pair of ground capacity C1, C2, described inductance L 1 is connected between the end of the output of rectification circuit and motor windings M, and described inductance L 2 is connected between the other end of another output of rectification circuit and motor windings M; The end of described a pair of ground capacity C1, C2 is connected respectively on two lead-out terminals of described rectification circuit, other end ground connection.The output of described rectification circuit a pair of fly-wheel diode in parallel.

With reference to Fig. 3, the alternating current output waveform is a sine wave, by an output pulsating voltage after the rectification of bridge heap, see Fig. 4, if this dc pulse moving voltage directly imports armature, because during voltage and crest, the time and trough will cause dc motor speed fluctuation bigger, be difficult to control.

Filter circuit II between rectification circuit and armature then can keep the stable of output voltage effectively.When voltage was in crest, the A point voltage was greater than the B point voltage, and electric capacity begins charging; When voltage begins to descend, the B point voltage is greater than the A point, and electric capacity begins discharge, and the voltage that A is ordered is steady relatively.Voltage rises and causes electric current to increase, and inductance produces a back-emf and plays the choked flow effect; Otherwise when voltage decline, inductance will play the afterflow effect, make the voltage at armature two ends comparatively steady all the time, be a stationary value basically, as shown in Figure 5.This circuit also plays the effect of disturbing of eliminating simultaneously.When brush passes through the commutator segment gap, flow to brush current and change suddenly, and the choke (inductance) that is connected in the circuit can be formed a low pass filter with ground capacity, effectively suppress conducted noise, eliminate and conduct in disturbing.

Experiment showed, the product for same size, adopt the permanent magnet DC motor of Alternating Current Power Supply of the present utility model, its efficient can reach 65%～80%, and starting torque is 2.5～5 times of rated moment; And directly adopt alternating current machine, its efficient generally to have only 35%～50%, and starting torque generally is slightly less than rated moment, this shows, and the utility model can improve the starting and the runnability of motor greatly.

The utility model is not limited to above-mentioned execution mode; no matter motor body is the permanent magnet DC motor of which kind of type; no matter also do any variation on its shape or the structure, everyly all drop within the protection range of the present utility model at the motor that is provided with a rectifying and wave-filtering front end circuit on the permanent magnet DC motor body in order to adapt to Alternating Current Power Supply.

Claims

1, the permanent magnet DC motor of Alternating Current Power Supply comprises this machine of permanent magnet DC motor, it is characterized in that also being provided with a current rectifying and wave filtering circuit.

2, the permanent magnet DC motor of Alternating Current Power Supply as claimed in claim 1 is characterized in that described rectification circuit is a bridge rectifier.

3, the permanent magnet DC motor of Alternating Current Power Supply as claimed in claim 1, it is characterized in that described filter circuit comprises a pair of inductance and a pair of ground capacity, described a pair of inductance is connected between the output and motor windings of rectification circuit, and an end of described ground capacity is connected on the output of described rectification circuit.

4, the permanent magnet DC motor of Alternating Current Power Supply as claimed in claim 3 is characterized in that the output a pair of fly-wheel diode in parallel of described rectification circuit.

5,, it is characterized in that described current rectifying and wave filtering circuit is arranged on the rear end cap of motor as the permanent magnet DC motor of any one described Alternating Current Power Supply of claim 1～4.