CN212486332U - Permanent magnet type direct current micromotor - Google Patents

Abstract

The utility model discloses a permanent magnetism type direct current micromotor, including the axle and suit in proper order in epaxial rotor subassembly, stator module, brush yoke and special circuit board, set up special groove on the brush yoke and be used for placing thermistor PTC, set up the pin hole that is used for connecting the PTC lead wire on the special circuit board, rectifier bridge is laid in the outside of special circuit board. The utility model has simple and compact structure, abandons the traditional AC single-phase series excitation motor, and arranges the rectifier bridge by arranging a special circuit board, so that the AC is more convenient to be converted into DC; the PTC is placed in the special groove in the motor, so that the PTC is convenient to place, the placement of other parts in the motor cannot be influenced, and the operation of the commutator cannot be interfered. The motor is small in size, simple and practical in structure, integrated and integrated in internal parts, high in reliability and good in robustness, and is very suitable for electric appliances which are more and more compact in structure and more narrow in installation space. Especially, the effect of reducing the installation space of the air pump in the household appliance is obvious.

Description

Permanent magnet type direct current micromotor

Technical Field

The utility model relates to a micromotor technical field especially relates to a permanent magnetism type direct current micromotor.

Background

At present, an alternating current single-phase series motor is commonly used as a motor of a household air pump in the world, particularly in European and American industrial developed countries. The volume of the alternating-current single-phase series motor is larger, the overall volume of the existing household air pump is smaller and smaller, the overall structure is more and more compact, under the background, the volume of the motor required by manufacturers and terminal customers of the air pump is more and more exquisite, and the size of parts and the installation space are continuously compressed. Moreover, the working voltage of the traditional motor is direct current, the motors for household and similar purposes are generally supplied with power by alternating current, direct current power supplies in families are not easy to obtain, and if the motor is applied to an air pump, a circuit board needs to be additionally arranged in the whole air pump, so that the defect of installation space in the air pump is further caused.

Besides, the micro-motor for air pump application usually needs to have the protection of motor overcurrent and overload, and the industry generally uses thermistor PTC. The ceramic PTC has low resistance below the Curie temperature, is suitable for normal operation of the motor, and when the motor is overloaded and overcurrent occurs, the PTC temperature rises sharply, and the PTC resistance increases in a step manner and acts when the PTC temperature reaches above the Curie temperature, so that a motor circuit is protected from being damaged. In practical cases, the placement of the PTC is always the focus of attention of the whole machine, and the operation time and the reset time of the PTC are affected by the height of the placement position, the distance from a heat source, the area of exposed cooling medium and the like. The traditional method is to place the PTC outside the motor or on the complete machine of an electric appliance such as an air pump, etc., thus greatly increasing the volume and space of the complete machine and being not beneficial to the development of the industry.

Therefore, how to reduce the motor volume, solve the space bottleneck problem of complete machine installation is the utility model discloses a problem that awaits a urgent need to solve.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a novel micromotor abandons traditional single-phase series excitation motor of interchange, adopts simple structure's permanent magnetism formula DC motor, and compact structure is simple and practical, and installation space is more and more narrow and small electrical apparatus is very suitable for.

In order to achieve the above object, the utility model provides a following scheme:

the utility model provides a permanent magnet type direct current micromotor, which comprises a shaft, a rotor component, magnetic steel, a brush holder and a special circuit board, wherein the rotor component, the magnetic steel, the brush holder and the special circuit board are sequentially sleeved on the shaft, the magnetic steel is sleeved outside the rotor component, a special groove is arranged on the brush holder and is used for placing a thermistor PTC, and the special groove and the placed PTC do not influence the installation of internal parts of the motor; the special circuit board is provided with pin holes for connecting the PTC lead wires, and the outer side of the special circuit board is used for placing a rectifier bridge so as to convert alternating current into direct current.

Optionally, the rectifier bridge is a 4-pin integrated patch rectifier bridge.

Optionally, the thermistor PTC is a ceramic PTC.

Optionally, carbon brush assemblies are mounted on two sides of the brush holder.

Optionally, a bearing chamber for accommodating a bearing is arranged in the brush holder, and the bearing is fixed in the bearing chamber through a clamping ring.

Optionally, the shaft further comprises a PCB protection cover arranged at the rear end of the shaft, and the PCB protection cover is used for protecting the circuit board.

Optionally, a lead groove and an outward convex barb angle are arranged on the PCB protective cover, and the PCB protective cover is clamped on the brush holder through the barb angle.

Optionally, the brush holder further comprises a casing arranged at the front end of the shaft, and the casing is in butt joint with the brush holder.

Optionally, the rotor assembly passes including close-fitting in proper order end plate, rotor core and the commutator of axle, evenly twine the enameled wire on the rotor core, rotor core's inslot is provided with slot wedge and slot paper, be used for with the enameled wire with rotor core separation constitutes independent insulating system.

Optionally, the number of the magnetic steels is two, a gap is reserved between the two magnetic steels, a U-shaped spring is installed in the gap, and the two elastic pieces of the U-shaped spring are respectively abutted to the two magnetic steels.

The utility model discloses for prior art gain following technological effect:

the permanent magnet direct current micromotor provided by the utility model has simple and compact structure, abandons the traditional alternating current single-phase series excitation motor, and arranges the rectifier bridge by arranging a special circuit board, so that the alternating current is more convenient to be converted into the direct current; the PTC is placed in the special groove in the motor, so that the PTC is convenient to place, the placement of other parts in the motor cannot be influenced, and the operation of the commutator cannot be interfered. The motor is small in size, simple and practical in structure, integrated and integrated in internal parts, high in reliability and good in robustness, is very suitable for electrical appliances with more and more compact complete machine structures and more narrow installation spaces, is especially obvious in effect of reducing the installation space of the air pump in household appliances, and can also be used for reference and popularization for micromotors in other fields.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic view of the overall structure of the motor of the present invention;

fig. 2 is an exploded view of the motor of the present invention;

fig. 3 is a schematic structural diagram of a dedicated circuit board in the motor of the present invention;

fig. 4 is a front view of a dedicated circuit board in the motor of the present invention;

fig. 5 is a schematic structural view of a brush holder in the motor of the present invention;

FIG. 6 is a front view of a brush holder in the motor of the present invention;

fig. 7 is a schematic view of the installation of the brush holder in the motor of the present invention;

fig. 8 is a schematic sectional view of a brush holder in the motor of the present invention;

FIG. 9 is a diagram showing the effect of placing PTC elements according to the present invention;

FIG. 10 is a schematic view of the PTC electrical connection of the present invention;

fig. 11 is a schematic structural view of a PCB protection cover in the motor of the present invention;

fig. 12 is a side view of the PCB shield of the motor of the present invention;

fig. 13 is a schematic diagram of an EMC electrical wiring according to the second embodiment of the present invention;

fig. 14 is a schematic structural diagram of an EMC circuit board in the second embodiment of the present invention;

fig. 15 is a schematic view of an EMC circuit board according to a second embodiment of the present invention;

wherein the reference numerals are: 1-machine shell, 2-magnetic steel, 3-U-shaped spring, 4-enameled wire, 5-bearing, 6-shaft, 7-rotor core, 8-end plate, 9-commutator, 10-clamping ring, 11-bearing, 12-brush holder, 12-1-special groove, 12-2-mounting hole, 13-electric connecting piece, 14-special circuit board, 14-1-pin hole, 14-2-insulating groove, 14-3-rectifier bridge, 14-4-positioning hole, 14-5-terminal hole, 15-PTC, 16-PTC lead, 17-PCB protective cover, 17-1-lead groove, 17-2-barb angle, 18-torsion spring, 19-carbon brush, 20-groove wedge, 21-slot paper; 22-EMC circuit board, 22-1-X electric capacity.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention is described in detail with reference to the accompanying drawings and the detailed description.

The first embodiment is as follows:

as shown in fig. 1-12, the embodiment provides a permanent magnet type dc micro-motor, which includes a shaft 6, and a rotor assembly, a magnetic steel 2, a brush holder 12 and a dedicated circuit board 14, which are sequentially sleeved on the shaft 6, wherein the magnetic steel 2 is sleeved outside the rotor assembly, the brush holder 12 is provided with a dedicated groove 12-1 for placing a thermistor PTC, and the dedicated groove 12-1 for placing the PTC15 do not affect the installation of other parts inside the motor, and the specific position of the dedicated groove is shown in fig. 6; the special circuit board 14 is provided with a pin hole 14-1 for connecting the PTC lead 16, and the outer side of the special circuit board 14 is used for placing a rectifier bridge 14-3, so that the alternating current is more conveniently converted into the direct current.

In this embodiment, as shown in fig. 3 and 4, a dedicated circuit board 14 is additionally designed at the rear end of the motor for placing a rectifier bridge 14-3, so that the conversion of alternating current into direct current is more convenient; meanwhile, the whole machine does not need to be additionally provided with a circuit board. As a preferred scheme, a 4-pin integrated patch rectifier bridge is adopted in this embodiment, so as to facilitate space compression of the circuit board. The operating principle of the rectifier bridge 14-3 and the required circuit connection are well known in the art and will not be described herein.

In this embodiment, the micro motor used as an air pump generally needs to be protected from overcurrent and overload, and the industry generally uses a thermistor PTC. The ceramic PTC has low resistance below the Curie temperature, is suitable for normal operation of the motor, and when the motor is overloaded and overcurrent occurs, the PTC temperature rises sharply, and the PTC resistance increases in a step manner and acts when the PTC temperature reaches above the Curie temperature, so that a motor circuit is protected from being damaged. In addition, the PTC operation time and the reset time are affected by the height of the PTC placement position, the distance from the heat source, the area of the exposed cooling medium, and the like. On the basis of sufficient performance verification, the present embodiment places the PTC15 inside the motor while the PTC lead 16 is soldered in the pin hole 14-1 of the above-mentioned dedicated wiring board 14. As shown in fig. 3 and 4, the dedicated circuit board 14 is provided with pin holes (for connecting PTC leads) 14-1, insulation grooves 14-2, terminal holes (holes symmetrical on both sides) 14-5, and positioning holes 14-4. Meanwhile, in order to conveniently place the PTC15, the back end cover of the motor, namely the brush holder 12, is provided with a special groove 12-1, and the body of the PTC15 is placed in the groove. The special groove has no influence on the placement of other parts in the motor, such as the carbon brush 19, the torsion spring 18, the electric connecting piece 13 and the like, and the PTC15 is placed in the special groove, so that the placement of the parts in the motor is not influenced, and the operation of the commutator 9 is not interfered. The principle of the PTC electrical wiring in this embodiment is shown in fig. 10.

In this embodiment, as shown in fig. 7, carbon brushes 19 are installed on both sides of the brush holder 12; the brush holder 12 is centrally provided with a bearing chamber for accommodating the bearing 11, and the bearing 11 is fixed in the bearing chamber by the clamping ring 10, as shown in fig. 8. Other structural descriptions of the brush holder in this embodiment, and the installation form of other components such as carbon brushes and the like can be found in patent CN 208424037U.

In this embodiment, as shown in fig. 1, in order to increase the reliability of the circuit board and reduce the external force and the external conductive medium and dust entering the circuit board, a dedicated circuit board cover, hereinafter referred to as a PCB protection cover 17, is added. The PCB protection cover 17 can protect the circuit board well, and the installation thereof should also save space and reduce the volume as much as possible. Preferably, the brush holder 12 of the present embodiment is provided with mounting holes 12-2 (two diagonal square holes in fig. 6), and as shown in fig. 11-12, the bottom of the PCB protection cover 17 is provided with inverted hook pins 17-2, and the inverted hook pins 17-2 are inserted into the mounting holes 12-2 to form a snap connection with the brush holder 12, so that the fastening and the non-falling off are realized, the installation is convenient, and the time and the labor are saved. Meanwhile, a lead groove 17-1 is also arranged on the PCB protective cover 17, and the PTC lead 16 can be fixed. In order to facilitate the installation of the load at the shaft extension end by a customer, a load installation process hole is formed in the center of the PCB protection cover 17.

In this embodiment, as shown in fig. 1 and 2, the motor further includes a casing 1 disposed at a front end of the shaft 6, and the casing 1 is abutted to a front end surface of the brush holder 12 to protect the rotor assembly and the stator assembly and form a complete casing structure of the motor.

In this embodiment, as shown in fig. 2, the rotor assembly includes an end plate 8, a rotor core 7 and a commutator 9 that are sequentially and tightly fitted through the shaft 6, the rotor core 7 is uniformly wound with the enamel wire 4, and a slot wedge 20 and slot paper 21 are disposed in a slot of the rotor core 7, so as to separate the enamel wire 4 from the rotor core 7 to form an independent insulation system.

In this embodiment, as shown in fig. 2, the two pieces of magnetic steel 2 are uniformly distributed on the inner wall of the casing 1 and glued on the inner wall of the casing by glue; leave the clearance between two magnet steel 2, install U type spring 3 in the clearance, two shell fragments of U type spring 3 support respectively and lean on in two magnet steel 2, and the fastening magnet steel prevents that the magnet steel is not hard up, breaks away from, avoids the magnet steel to produce radial movement.

The installation process of each part of the motor is as follows:

firstly, an end plate 8, a rotor core 7 and a commutator 9 sequentially penetrate through a shaft 6 in a tight fit mode, an enameled wire 4 is uniformly placed in a groove of the rotor core 7, a slot wedge 20 and slot paper 21 are uniformly placed in the groove of the rotor core 7, the enameled wire 4 and the rotor core 7 are separated to form an independent insulation system, and the rotor assembly is formed by the components; the magnetic steel 2 of the stator component is sleeved outside the rotor component to form a main motor structure, and the main motor structure is arranged in the machine shell 1, so that the front end of the shaft 6 is supported in the machine shell 1 through the bearing 5. Then, the rear end of the shaft 6 is arranged in a rear end cover assembly (a brush holder 12), and the brush holder 12 is riveted and fastened with the machine shell 1, so that the front support, the rear support, the stator assembly and the rotor assembly are integrated; wherein, each bearing mesopore forms the close-fitting relation with axle 6, and axial fixity and radial support rotor circumferencial direction move. Then the special circuit board 14 is arranged, and is aligned and installed through the positioning column (arranged on the brush holder 12), the positioning hole 14-4, the terminal hole 14-5 and the electric connection piece 13, and is horizontally placed through the positioning hole 14-4 of the limiting column contact circuit board, and is fixed through conducting connection of the electric connection piece 13, so that the circuit board is completely fixed. And finally, installing the PCB protection cover 17, and inserting the two barb corners 17-2 of the PCB protection cover 17 into the installation holes 12-2, wherein the parts are completely fixed and do not loosen. The motor structure is very suitable for various industries developing in the direction of miniaturization, integration and lightness, particularly the industry of air pumps, and the micro motor with the new structure is expected to have blowout type development in a short period of several years.

Example two:

the embodiment is a preferred scheme that the motor has no electromagnetic compatibility requirement, and the embodiment is designed and optimized for the following EMC requirement of the motor with the electromagnetic compatibility requirement. The main means for adapting to meet the EMC requirement is to filter out electromagnetic noise in different frequency bands by adding components such as X capacitor, Y capacitor, and inductor, and the EMC electrical wiring schematic diagram is shown in fig. 13.

As shown in fig. 14, in the embodiment, the EMC circuit board 22 is provided with the X capacitor 22-1, the rectifier bridge, the terminal, the inductor, the insulation slot, and the like, so that the component density is high, the structure is compact, and the mounting is convenient and fast. The overall external view of the motor with the circuit board mounted thereon is shown in fig. 15. The motor structure is only an extension of the structure, and the basic principle, the positioning mode, the installation method and the process operation are all consistent with the first embodiment. The motor structure is very suitable for various industries developing in the direction of miniaturization, integration and lightness, particularly the industry of air pumps, and the micro motor with the new structure is expected to have blowout type development in a short period of several years.

It should be noted that, as is obvious to a person skilled in the art, the invention is not limited to details of the above-described exemplary embodiments, but can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein, and any reference signs in the claims are not intended to be construed as limiting the claim concerned.

The utility model discloses a concrete example is applied to explain the principle and the implementation mode of the utility model, and the explanation of the above example is only used to help understand the method and the core idea of the utility model; meanwhile, for the general technical personnel in the field, according to the idea of the present invention, there are changes in the concrete implementation and the application scope. In summary, the content of the present specification should not be construed as a limitation of the present invention.

Claims (10)

1. A permanent magnet type direct current micromotor is characterized in that: the magnetic steel brush comprises a shaft, and a rotor assembly, magnetic steel, a brush holder and a special circuit board which are sequentially sleeved on the shaft, wherein the magnetic steel is sleeved outside the rotor assembly, a special groove is formed in the brush holder and used for placing a thermistor PTC (positive temperature coefficient), and the special groove and the placed PTC do not influence the installation of internal parts of a motor; the special circuit board is provided with pin holes for connecting the PTC lead wires, and the outer side of the special circuit board is used for placing a rectifier bridge so as to convert alternating current into direct current.

2. The permanent magnet direct current micro-motor according to claim 1, characterized in that: the rectifier bridge is a 4-pin integrated patch type rectifier bridge.

3. The permanent magnet direct current micro-motor according to claim 1, characterized in that: the thermistor PTC is ceramic PTC.

4. The permanent magnet direct current micro-motor according to claim 1, characterized in that: and carbon brush assemblies are arranged on two sides of the brush holder.

5. The permanent magnet direct current micro-motor according to claim 1, characterized in that: a bearing chamber used for containing a bearing is arranged in the brush frame, and the bearing is fixed in the bearing chamber through a tight ring.

6. The permanent magnet direct current micro-motor according to claim 1, characterized in that: the PCB protection cover is arranged at the rear end of the shaft and used for protecting the circuit board.

7. The permanent magnet direct current micro-motor according to claim 6, characterized in that: the PCB protection cover is provided with an outward convex barb angle, and the PCB protection cover is clamped on the brush frame through the barb angle.

8. The permanent magnet direct current micro-motor according to claim 1, characterized in that: the brush holder is characterized by further comprising a casing arranged at the front end of the shaft, and the casing is in butt joint with the brush holder.

9. The permanent magnet direct current micro-motor according to claim 1, characterized in that: the rotor subassembly passes including close-fitting in proper order end plate, rotor core and the commutator of axle, evenly twine on the rotor core has the enameled wire, rotor core's inslot is provided with slot wedge and groove paper, be used for with the enameled wire with rotor core separation constitutes independent insulating system.

10. The permanent magnet direct current micro-motor according to claim 1, characterized in that: the two pieces of magnetic steel are arranged, a gap is reserved between the two pieces of magnetic steel, a U-shaped spring is installed in the gap, and two elastic pieces of the U-shaped spring are respectively abutted to the two pieces of magnetic steel.

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