CN210246639U

CN210246639U - Direct current motor and drive circuit thereof

Info

Publication number: CN210246639U
Application number: CN201921257344.5U
Authority: CN
Inventors: Xiaowei Chen; 陈校伟; Yangya Zhao; 赵洋亚; Jiaming Yang; 杨佳明
Original assignee: XIAMEN XINZHONGDA TECHNOLOGY CO LTD
Current assignee: XIAMEN XINZHONGDA TECHNOLOGY CO LTD
Priority date: 2019-08-05
Filing date: 2019-08-05
Publication date: 2020-04-03
Anticipated expiration: 2029-08-05

Abstract

The utility model discloses a direct current motor and drive circuit thereof, including rectifier bridge and load, this rectifier bridge includes first interchange, the second exchanges, four pins of positive pole and negative pole, still include PPTC, this PPTC's input and alternating current power supply's L line connection, this PPTC's output is connected with the first alternating current pin of this rectifier bridge, alternating current power supply's N line is connected with the second alternating current pin of this rectifier bridge, the positive pole pin of this rectifier bridge and the input of this load are connected, the negative pole pin of this rectifier bridge and the output of this load are connected. The PPTC is connected between an L line of an alternating current power supply and a rectifier bridge, the PPTC is arranged at the foremost end of the circuit and is directly connected with a live wire, and after the PPTC cuts off the circuit, the electric connection between the electronic component and the live wire can be directly cut off, so that the electronic component behind the PPTC is prevented from being electrified, components in the circuit are protected, and the safety performance of the motor is improved.

Description

Direct current motor and drive circuit thereof

Technical Field

The utility model relates to a direct current motor and drive circuit thereof.

Background

The direct current motor utilizes a rectifier bridge to convert an external alternating current power supply, and then outputs direct current to supply power to a rotor of the motor. In order to obtain safe and reliable operation characteristics, an overcurrent fuse or a temperature fuse is usually installed in the circuit, and the overcurrent fuse or the temperature fuse automatically cuts off the circuit in an abnormal state, so that the rotor is protected. However, the current fuse protects the motor once and cannot be reused. Although the temperature fuse can be automatically reset and reused, the temperature control price is high, the volume is large, the contact area and the close degree of the temperature control temperature sensing surface and the heating part of the motor influence the sensitivity of the temperature control temperature sensing surface, and the performance is unstable. Furthermore, the overcurrent fuse and the temperature fuse of the conventional circuit are connected between the rectifier bridge and the rotor to protect the rotor, but after the circuit is automatically cut off by the overcurrent fuse and the temperature fuse, electronic components at the upstream of the overcurrent fuse and the temperature fuse, such as the rectifier bridge, are also at risk of being electrified, even the shell of the motor is electrified, so that the risk of electric shock exists, and great potential safety hazard is formed for users.

SUMMERY OF THE UTILITY MODEL

The utility model provides a direct current motor and drive circuit thereof, it has overcome the not enough that the background art exists. The utility model provides a technical scheme that its technical problem adopted is:

the direct current motor driving circuit comprises a rectifier bridge and a load, wherein the rectifier bridge comprises a first alternating current pin, a second alternating current pin, a positive electrode pin and a negative electrode pin, the direct current motor driving circuit further comprises a PPTC (Power Point controller), an input end of the PPTC is connected with an L line of an alternating current power supply, an output end of the PPTC is connected with the first alternating current pin of the rectifier bridge, an N line of the alternating current power supply is connected with the second alternating current pin of the rectifier bridge, the positive electrode pin of the rectifier bridge is connected with the input end of the load, and the negative electrode pin of the rectifier bridge is connected with the output end of the load.

In a preferred embodiment: the weight ratio of the PPTC internal high-density polyethylene, the carbon black and the magnesium hydroxide is 90-110:80-100: 120-140.

In a preferred embodiment: the weight ratio of the high-density polyethylene to the carbon black to the magnesium hydroxide is 100:90: 130.

In a preferred embodiment: the outer surface of the PPTC is wrapped with at least three protective layers.

The direct current motor comprises a stator, a rotor, a rectifier bridge and two carbon brushes, wherein the stator comprises a shell and magnetic shoes arranged in the shell, the rotor comprises a rotating shaft and a commutator arranged on the rotating shaft, the rotor is rotatably erected in the stator, two ends of the rotating shaft axially extend out of two end faces of the shell respectively, the two carbon brushes are symmetrically arranged on the shell and are in conductive contact with the commutator, the rectifier bridge comprises a first alternating current, a second alternating current, four pins of a positive electrode and a negative electrode, and further comprises a PPTC, the rectifier bridge and the PPTC are arranged on the shell, a positive electrode pin of the rectifier bridge is connected with one of the carbon brushes, the negative electrode pin of the rectifier bridge is connected with another carbon brush, the output end of the PPTC is connected with the first alternating current pin of the rectifier bridge, when in work, the input end of the PPTC is connected with an L line of an alternating current power supply, and an N line of the alternating current power supply is connected with a second alternating current pin of the rectifier bridge.

In a preferred embodiment: the shell comprises a cylinder body and an insulating end cover, and the PPTC and the rectifier bridge are arranged on the insulating end cover.

In a preferred embodiment: the carbon brush is arranged on the insulation end cover.

Compared with the background technology, the technical scheme has the following advantages:

the PPTC is connected between an L line of an alternating current power supply and a rectifier bridge, the PPTC is arranged at the foremost end of a circuit and is directly connected with a live wire, and after the PPTC cuts off the circuit, the electric connection between an electronic component and the live wire can be directly cut off, so that the electronic component behind the PPTC is prevented from being electrified, components in the circuit are protected, and the safety performance of the motor is improved.

PPTC can be easily made into other shapes, so that the internal layout of the motor is met, the space is saved, and the volume of the motor is reduced.

PPTC mixes conductive particles into a non-conductive polymer matrix to form a conductive path. When a circuit is short-circuited or overloaded, the internal temperature of a product is increased by a large current flowing through the PPTC, and when the temperature reaches a Curie point, the PPTC substrate thermally expands, most of conductive chains are disconnected, the resistance is increased, the current is reduced, and the PPTC limits and protects the circuit. When power failure and fault are eliminated, the temperature is reduced, the PPTC substrate is shrunk, the conductive chains are reconnected, the resistance is reduced, and the PPTC can automatically recover to a normal state, so that the PPTC can be continuously used. The PPTC has stable and reliable performance, and can improve the operation stability of the circuit.

And 4, the PPTC and the rectifier bridge are arranged on the insulating end cover, so that the internal structure of the motor can be simplified.

Drawings

The present invention will be further explained with reference to the drawings and examples.

Fig. 1 shows a schematic diagram of a dc motor driving circuit.

Fig. 2 shows a schematic front view of a dc motor.

Fig. 3 is an exploded view of the dc motor shown in fig. 2.

Detailed Description

Referring to fig. 1, a dc motor driving circuit includes a rectifier bridge 01 and a load 02, where the rectifier bridge 01 includes a first ac pin 011, a second ac pin 012, a positive pin 013, a negative pin 014, and a PPTC03 (polymer positive temperature coefficient) thermistor, where the PPTC is a polymer PPTC thermistor for overcurrent protection. The input terminal of the PPTC is connected to the L line of the ac power supply 04, the output terminal of the PPTC is connected to the first ac pin 011 of the rectifier bridge 01, the N line of the ac power supply 04 is connected to the second ac pin 012 of the rectifier bridge, the positive pin 013 of the rectifier bridge is connected to the input terminal of the load 02, and the negative pin 014 of the rectifier bridge is connected to the output terminal of the load 02. The external alternating current is converted through the rectifier bridge 01, and the direct current is output to supply power to the load 02. In the motor, the load 02 is a rotor.

The weight ratio of the high-density polyethylene, the carbon black and the magnesium hydroxide in the PPTC is 90-110:80-100:120-140, and preferably, the weight ratio of the high-density polyethylene, the carbon black and the magnesium hydroxide is 100:90: 130. The outer surface of the PPTC is wrapped to the four protective layers, so that the PPTC has good pressure resistance.

Referring to fig. 2 and fig. 3, the dc motor using the driving circuit includes a stator 10, a rotor 20 and two carbon brushes, wherein the stator 10 includes a housing 11 and magnetic shoes disposed in the housing, the rotor 20 includes a rotating shaft 21 and a commutator 22 disposed on the rotating shaft, the rotor 20 is rotatably erected in the stator 10, and two ends of the rotating shaft 21 respectively axially extend out of two end faces of the housing 11. The two carbon brushes are arranged symmetrically on the housing 11 and are in electrically conductive contact with the commutator 22. The connection structure of the stator 10, the rotor 20, and the carbon brushes is not described much. The rectifier bridge 30 and the PPTC40 are further included, and the rectifier bridge 30 and the PPTC40 are arranged on the shell 11. The rectifier bridge 30 includes a first ac pin, a second ac pin, a positive pin and a negative pin, the positive pin of the rectifier bridge is connected to one of the carbon brushes, and the negative pin of the rectifier bridge is connected to the other carbon brush. The output end of the PPTC40 is connected with a first alternating current pin of the rectifier bridge, when the rectifier bridge works, the input end of the PPTC40 is connected with an L line of an alternating current power supply, and an N line of the alternating current power supply is connected with a second alternating current pin of the rectifier bridge.

The housing 11 includes a barrel 112 and an insulating end cap 114, the PPTC40 and the rectifier bridge 30 being disposed on the insulating end cap 114. The carbon brushes are also disposed on the insulating end cap 114 on the inside face of the insulating end cap. Therefore, the internal structure of the motor is simplified, and the PPTC40 and the rectifier bridge 30 are arranged on the insulating end cover 114, so that the barrel 112 can be effectively prevented from being electrified, and the safety performance is improved.

The above description is only a preferred embodiment of the present invention, and therefore the scope of the present invention should not be limited by this description, and all equivalent changes and modifications made within the scope and the specification of the present invention should be covered by the present invention.

Claims

1. Direct current motor drive circuit, including rectifier bridge and load, this rectifier bridge includes four pins of first interchange, second interchange, positive pole and negative pole, its characterized in that: the input end of the PPTC is connected with an L line of an alternating current power supply, the output end of the PPTC is connected with a first alternating current pin of the rectifier bridge, an N line of the alternating current power supply is connected with a second alternating current pin of the rectifier bridge, an anode pin of the rectifier bridge is connected with the input end of the load, and a cathode pin of the rectifier bridge is connected with the output end of the load.

2. The direct current motor drive circuit according to claim 1, characterized in that: the outer surface of the PPTC is wrapped with at least three protective layers.

3. Direct current motor, including stator, rotor, rectifier bridge and two carbon brushes, this stator includes the shell and sets up the magnetic shoe in this shell, and this rotor includes the pivot and sets up at this epaxial commutator of commentaries on classics, and this rotor rotationally erects in the middle of this stator, and the both ends of this pivot are the axial respectively and stretch out the both ends face of this shell, two the carbon brush symmetry sets up on this shell and with this commutator conductive contact, this rectifier bridge includes four pins of first interchange, second interchange, positive pole and negative pole, its characterized in that: the rectifier bridge and the PPTC are arranged on the shell, an anode pin of the rectifier bridge is connected with one carbon brush, a cathode pin of the rectifier bridge is connected with the other carbon brush, an output end of the PPTC is connected with a first alternating current pin of the rectifier bridge, when the rectifier bridge works, an input end of the PPTC is connected with an L line of an alternating current power supply, and an N line of the alternating current power supply is connected with a second alternating current pin of the rectifier bridge.

4. The direct current motor according to claim 3, characterized in that: the shell comprises a cylinder body and an insulating end cover, and the PPTC and the rectifier bridge are arranged on the insulating end cover.

5. The direct current motor according to claim 4, characterized in that: the carbon brush is arranged on the insulating end cover.