CN216436904U - 700 miniature ferrite permanent magnet direct current motor - Google Patents

Abstract

Compared with a traditional rotor with a 6-tooth iron core and 6-petal commutator combined structure and a rotor with a 5-tooth iron core and 10-petal commutator combined structure, the 700 # miniature ferrite permanent magnet direct current motor with a four-pole two-carbon brush structure has a relatively larger rotor outer diameter, and adopts the combination of a 10-tooth iron core and a 10-petal commutator. The sectional area of the enameled wire which can be accommodated in the iron core groove is increased by reasonably increasing the outer diameter of the rotor, and the groove filling rate of the winding is improved in a winding parallel connection mode, so that the loss of total magnetic flux caused by the reduction of the thickness of the magnetic shoe due to the increase of the outer diameter of the rotor is compensated. Through halving the number of the equalizing lines and adjusting the positions of the ending hooks, the number of the enameled wires hung on the commutator hook is reduced to 2 or 1, the compact design of the rotor in the axial direction is realized, and the butt-welding quality of the rotor is also improved. The use of the equalizer and the symmetry of the rotor across-slot winding make the resistance of the winding or the inter-sheet resistance of the rotor more uniform, and also improve the balance of the rotor.

Description

700 miniature ferrite permanent magnet direct current motor

Technical Field

The utility model relates to a 700 miniature ferrite permanent magnet direct current motor of two carbon brush structures of quadrupole.

Background

In a 700 # micro ferrite permanent magnet dc motor with an outer diameter of phi 42.2mm, a four-pole magnetic shoe structure is generally adopted in order to pursue a larger output power under a certain volume. Considering factors such as the outer diameter of the commutator, the length of the carbon brush, the layout of the additional capacitor in the limited space of the rubber cover and the like, the 700 # micro ferrite permanent magnet direct current motor adopts a pair of carbon brush structures.

When the motor works, the larger the load current is, the larger the sparks generated between the carbon brush and the commutator are, and the faster the carbon brush is worn, so that the service life of the carbon brush and the commutator is shorter. In order to improve the commutation of the motor and reduce the sparks during the operation of the carbon brush, the rotor structure of the 5-tooth iron core and the 5-petal commutator is generally designed to be adjusted to be a rotor structure of a 6-tooth iron core and a 6-petal commutator or a rotor structure of a 5-tooth iron core and a 10-petal commutator.

In order to ensure the level on the opposite commutator pieces to be consistent, the hooks on the opposite commutator pieces are connected by a short-circuited equalizing line. For example, in the rotor structure of a 6-tooth iron core and a 6-lobe commutator, if a double-flying-fork opposite winding mode is adopted, the total number of the equalizing lines and the number of the lobes of the commutator are consistent to 6. Therefore, on one hand, a larger space is needed to be designed between the rotor core and the commutator to accommodate the voltage equalizing wire wound around the neck, so that the total length of the rotor is lengthened; on the other hand, during winding of a rotor, the initial hook and the final hook of the enameled wire on the commutator are identical (namely the initial hook and the final hook are the same hook), so that the number of the enameled wires hung on the initial hook (also the final hook) of the commutator is more than 2, and the difficulty of the rotor butt-welding process is increased. Because the wire diameter of the enameled wire adopted by the rotor is thicker when larger output power is pursued, the length of the commutator hook needs to be increased in design.

For a traditional 5-tooth iron core, if the winding pitch is larger than one slot, the size of front and rear adjacent windings cannot be consistent due to the lap winding, so that the unevenness of winding resistance and the unbalance of a rotor are increased.

The output power of the motor is higher, the wire diameter of the enameled wire of the rotor is thicker correspondingly, the winding displacement of the rotor during winding is influenced, the full rate of the rotor slot is reduced, if the outer diameter of the rotor is not changed, the number of teeth of the rotor iron core is increased, the sectional area of the iron core slot capable of accommodating the enameled wire is reduced, and the output power and the torque of the motor are reduced.

Under the condition that the factors such as the material, the wire diameter, the number of winding turns, the length of a torsion spring arm, the torsion angle and the like of the carbon brush torsion spring are fixed, because the traditional torsion spring arm is only bent at one position and the space of a No. 700 miniature ferrite permanent magnet direct current motor is limited, the components (namely the elasticity of the carbon brush) of the torsion spring arm and the carbon brush in the directions parallel to the central axis of the carbon brush and vertical to the surface of the commutator are small in stress, so that the sparks generated when the carbon brush and the commutator rub or commutate when the motor runs are large; on the contrary, the other stress component of the torsion spring arm and the carbon brush is that the acting force of the side wall of the carbon brush and the inner wall of the carbon brush barrel is larger, so that the friction force of the side wall of the carbon brush and the inner wall of the carbon brush barrel is also larger, and the balance of the elastic force of the carbon brush is influenced.

Disclosure of Invention

The utility model provides a No. 700 miniature ferrite permanent magnet direct current motor to solve the following problem that No. 700 miniature ferrite permanent magnet direct current motor of two carbon brush structures of current quadrupole exists:

1) the number of the equalizing wires is large, the number of enameled wires hung on a commutator hook is more than 2, the neck part between the commutator and the iron core is too swollen when the rotor is wound, and the butt-welding process of the rotor is difficult;

2) the full rate of a winding slot of the rotor is low, the winding resistance is not uniform, and the unbalance amount of the rotor is large;

3) the number of teeth of the rotor core with the same outer diameter is increased, so that the sectional area of a groove of the rotor core, which can accommodate the enameled wire, is reduced, and the output power and the torque of the motor are correspondingly reduced;

4) the commutating sparks and the running sparks of the carbon brush of the motor are large, and the service lives of the carbon brush and the commutator are short.

The utility model provides a technical scheme that its technical problem adopted is: a700 # micro ferrite permanent magnet direct current motor is characterized in that 4 magnetic shoes are uniformly arranged in the inner circumferential direction of a 700 # housing with the outer diameter of phi 42.2mm, and the N poles and the S poles of the magnetic shoes are alternately distributed; on the cross section of the outer cylinder of the motor shell, a pair of carbon brushes is distributed in 90 degrees, the central lines of the carbon brushes are respectively aligned with the central lines of the two opposite poles of the magnetic shoe, and the outer ends of the carbon brushes are provided with torsion springs; a rotor is rotatably arranged on the axis of the shell, a main shaft capable of rotating is arranged in the center of the rotor, an iron core and a commutator are arranged on the main shaft, and a commutator hook used for welding an enameled wire end of a winding is arranged on each segment of the commutator; the iron core is characterized in that the number of the iron core slots is 10, and the number of the commutator segments is the same as that of the iron core slots; the center line of each commutator hook is aligned with the center line of each core groove in the circumferential direction centered on the main shaft. Compared with the commutator segment, the hooks on the commutator segment are connected by only one equalizing line, and the total number of the equalizing lines is half of the number of the commutator segments.

The commutator hooks comprise a starting hook and a tail hook which are oppositely arranged on the commutator segment, and the starting hook and the tail hook are mutually connected through a voltage equalizing line, so that the number of enameled wires on all the commutator hooks is reduced to 2 or 1.

The single winding pitch spans three rotor slots, the adjacent windings in the front and the back are symmetrically arranged, and one internal winding spanning the three rotor slots is connected in parallel with the other external winding spanning the three rotor slots. The wire diameter of the enameled wire used for winding the rotor with the same output power is reduced, and the groove filling rate is higher.

The rotor has an outer diameter 10-15% greater than conventional 5-tooth and 6-tooth rotors. The loss of the output power and the torque of the motor caused by the increase of the number of teeth of the rotor iron core and the reduction of the sectional area of the slot of the iron core capable of accommodating the enameled wire is compensated.

The torsion spring is provided with two bends, and a second torsion spring arm bend is added between the bent part of the traditional first torsion spring arm and the tail part of the carbon brush so as to reduce an included angle between the torsion spring arm and the tail part of the carbon brush; correspondingly, a V-shaped notch is designed at the tail end of the carbon brush and used for accommodating the end part of the torsion spring. The torsion spring arm is bent at two positions, so that the stress angle between the torsion spring arm and the carbon brush is changed, the elasticity of the carbon brush is reasonably increased (note: the elasticity of the carbon brush is the component of the action of the torsion spring and the force of the carbon brush in the directions parallel to the central axis of the carbon brush and vertical to the surface of the commutator), the acting force of the side wall of the carbon brush and the inner wall of the carbon brush barrel is correspondingly reduced, and the friction force between the side wall of the carbon brush and the inner wall of the carbon brush barrel is further reduced. The space for the torsional spring arm to move in the plastic cover is matched with the bending angle of the torsional spring arm.

The beneficial effects of the utility model are summarized as follows:

1) the winding slot filling rate is improved in a winding parallel mode, the outer diameter of the rotor is reasonably increased to increase the sectional area of the iron core slot capable of accommodating the enameled wire, and the total working magnetic flux of the motor magnetic shoe with the four-pole two-carbon brush structure and the winding interlinkage is equivalent to that of a traditional motor magnetic shoe with 6-tooth iron cores and 6-petal commutators or 5-tooth iron cores and 10-petal commutators, and the torque is equivalent to that of the traditional motor magnetic shoe with the four-pole two-carbon brush structure and the winding interlinkage. The number of teeth of the iron core is increased, and the static torque of the rotor is reduced; the number of commutator segments is increased, and the commutation spark of the motor is improved.

2) The number of the equalizing lines is reduced by half; the position of the ending hook is adjusted, so that the number of the enameled wires hung on the commutator hook is reduced to 2 or 1, the problem that the neck part between the commutator and the iron core is too big when a rotor is wound is solved, and the difficulty of the rotor butt-welding process is reduced; the commutator hook length is shortened and the distance between the commutator and the iron core is shortened, so that the rotor can be designed to be more compact in the axial direction.

3) The use of the equalizing line and the symmetry of the rotor across-slot winding enable the resistance of the winding or the resistance between rotor sheets to be more uniform and also improve the balance of the rotor.

4) The elastic force of the carbon brush is reasonably increased by changing the stress angle between the torsion spring arm and the carbon brush, and the acting force between the side wall of the carbon brush and the inner wall of the carbon brush barrel is reduced, so that the friction force between the side wall of the carbon brush and the inner wall of the carbon brush barrel is reduced, the contact between the carbon brush and the surface of the commutator and the balance of the elastic force of the carbon brush are improved, and the sparks generated when the carbon brush and the commutator rub or commutate when the motor runs are reduced.

Drawings

Fig. 1 is an exploded view of the present invention;

fig. 2 is an axial cross-sectional view of the present invention;

fig. 3 is a cross-sectional view of the rotor of the present invention (cross-sectional view a-a of fig. 4);

fig. 4 is a view of one end of the rotor (provided with a commutator) of the present invention;

fig. 5 is a cross-sectional view of a conventional motor 700 # including a 6-tooth core and a four-pole two-carbon brush structure with a 6-segment commutator rotor;

fig. 6 is a cross-sectional view of a conventional motor 700 # having a four-pole two-carbon brush structure with a 5-tooth core and a 10-lobed commutator rotor;

figure 7 is a cross-sectional view of the present invention (at the commutator);

FIG. 8 is a schematic structural view of a conventional glue cap assembly;

fig. 9 is a schematic structural view of the rubber cover assembly of the present invention;

fig. 10 is a D-direction view of the carbon brush in fig. 8;

FIG. 11 is a right side view (90 clockwise rotation) of FIG. 10;

fig. 12 is an E-direction view of the carbon brush in fig. 9;

FIG. 13 is a right side view (90 clockwise rotation) of FIG. 12;

fig. 14 is a partially enlarged view of a conventional carbon brush and torsion spring structure;

fig. 15 is a partial enlarged view of the carbon brush and torsion spring structure of the present invention;

fig. 16 is a schematic view showing the installation position of the inner and outer windings of the rotor in the core according to the present invention;

fig. 17 is a schematic arrangement of the inner and outer windings of the rotor of the present invention;

fig. 18 is a schematic circuit diagram of the inner and outer windings of the present invention;

fig. 19 is a schematic diagram of the position connection of the winding hook, the tail hook and the equalizer line according to the present invention.

Description of reference numerals:

1. the magnetic brush comprises an iron cover, a bearing, a carbon brush, a torsion spring, a clamping groove, a capacitor, a carbon brush cylinder, a copper bottom plate, a plastic cover, a lead-out wire, an inner fan blade, a main shaft, a gasket (comprising an oil-proof gasket and an adjusting gasket), a commutator, a core, a winding, an outer winding, a winding body, a carbon brush body, a rubber column, a first torsion spring arm, a winding, a second torsion spring arm, a 28, a winding groove, a carbon brush, a spring, a second torsion spring, a third torsion spring, a second torsion spring; 30. the acting force of the side wall of the carbon brush and the inner wall of the carbon brush barrel is 31, the acting force of the torsion spring and the carbon brush is 32, the inner winding is 33, the outer winding is 34, the voltage equalizing wire is 35, the lifting hook is 36 and the tail hook is 36.

Detailed Description

Referring to fig. 1 and 2, the 700 # micro ferrite permanent magnet direct current motor with a four-pole two-carbon brush structure comprises an iron cover assembly, a rubber cover assembly, a stator and a rotor. The bearing 2 is arranged in the bearing chamber of the iron cover 1 to form an iron cover assembly. The rubber cover component (as shown in figure 9) comprises a plastic cover 9 of a main body; one end of the positive electrode lead wire 10 is spot-welded to the copper base plate 8 together with the shunt 22 of the positive electrode carbon brush 3. (note: if additional capacitors 6 are needed, the capacitor 6 pins at one end are also spot welded together); the lead wire 10 of the negative electrode and the braid 22 of the carbon brush 3 of the negative electrode are respectively spot-welded on two corners of the other copper base plate 8. The carbon brush barrel 7 is inserted into the corresponding holes of the copper bottom plate 8 and the plastic cover 9 and riveted together. The carbon brush body 24 is put into the carbon brush barrel 7, and the torsion spring 4 is arranged on the rubber column 25 of the plastic cover 9. 4 magnetic shoes 17 are uniformly arranged in the inner circumferential direction of the casing 19, N poles and S poles of the magnetic shoes 17 are alternately distributed, the magnetic shoes 17 are separated by butterfly positions of the casing 19, and a circle is supported by a slingshot 18. The magnetic shielding ring 20 is added on the outer part of the casing 19 to prevent the stator from magnetic leakage. As shown in fig. 3, the iron core 15 and the commutator 14 are pressed into the rotor shaft 12, and a retainer 21 is pressed into the rotor shaft to prevent the axial displacement of the rotor. After the rotor is coated, the windings 16 are wound around the core slots 28; the windings 16 are connected after being butt welded by the hook of the commutator 14. Finally, the inner fan blade 11 is added on one side of the iron core 15 close to the commutator 14 to reduce the temperature rise of the motor.

The input end of the rotor spindle 12 firstly penetrates an oil-proof gasket 13 and a plurality of adjusting gaskets 13, and correspondingly, the output end also penetrates a proper adjusting gasket 13. And then, after the rotor enters the stator, assembling the rubber cover assembly, covering the iron cover assembly, and sealing to finish the assembly of the No. 700 miniature ferrite permanent magnet direct current motor with the four-pole two-carbon brush structure.

Referring to fig. 4, the core 15 has 10 teeth, and the corresponding commutator 14 has 10 lobes. The center line of each commutator 14 hook is aligned with the center line of each core 15 slot in the circumferential direction centered on the main shaft 12.

Referring to fig. 7, 4 magnetic shoes 17 are uniformly installed in the inner circumferential direction of the casing 19, and the N poles and S poles of the magnetic shoes 17 are alternately distributed; on the cross section of the outer cylinder of the machine shell 19, a pair of carbon brushes 3 is distributed in 90 degrees, and the central lines of the carbon brushes 3 are respectively aligned with the central lines of the two opposite poles of the magnetic shoe 17.

The utility model discloses be the 700 motor that the external diameter is phi 42.2mm, include the two carbon brushes 3 structures of quadrupole (as shown in fig. 5) of 6 tooth iron cores 15 and 6 lamella commutator 14 rotors or include two carbon brushes 3 structures of quadrupole (as shown in fig. 6) of 5 tooth iron cores 15 and 10 lamella commutator 14 rotors more traditional, adopt 10 lamella commutators 14 on the one hand, improve the spark of switching-over (traditional 700 motor of number four pole two carbon brushes structure, do not have this kind of rotor structure, generally be iron core 5 teeth, correspondingly, commutator 5 lamella; on the other hand, the number of teeth of the iron core 15 is increased to 10 to reduce the static torque of the rotor. If the number of teeth of the rotor core 15 is increased without changing the outer diameter of the rotor, the sectional area of the core slot 28 for accommodating the enamel wire is decreased; however, if the outer diameter of the rotor is increased, the outer diameter of the motor is not changed, the thickness of the magnetic shoe 17 tends to be reduced, and the magnetic flux of the magnetic shoe 17 is reduced. In order to ensure that the total working magnetic flux of the motor magnetic shoe 17 and the winding 16 are linked is equivalent, on one hand, the outer diameter of the rotor is properly increased, the sectional area of the iron core groove 28 capable of accommodating the enameled wire is increased, and the availability of the iron core groove 28 is increased; on the other hand, by adopting the parallel connection mode of the windings 16 (as shown in fig. 18), on the premise of ensuring that the total current of the parallel connection count is not changed, the wire diameter of the enameled wire of a single winding 16 can be reduced, so that the wire arrangement during the winding is facilitated, and the slot fullness rate of the winding is further improved.

Under the condition that the torsion spring 4 has certain factors such as material, wire diameter, winding turns, torsion spring arm length and torsion angle, the action of the torsion spring 4 and the torsion spring action of the carbon brush 3 and the force 31 of the carbon brush are certain. Referring to fig. 8, the arm of the conventional torsion spring 4 has only one bend 26; in the present invention (as shown in fig. 9), a bend (second torsion spring arm bend) 27 is added to the torsion spring 4 arm, so as to change the stressed angle between the torsion spring arm and the carbon brush (as shown in fig. 14 and fig. 15), and reasonably increase the force component between the torsion spring 4 and the torsion spring of the carbon brush 3 and the force 31 of the carbon brush in the direction parallel to the carbon brush central axis and perpendicular to the commutator surface, i.e. the carbon brush elastic force 29; on the contrary, the acting force 30 between the carbon brush side wall and the inner wall of the carbon brush barrel is reduced, so that the friction force between the carbon brush side wall and the inner wall of the carbon brush barrel is reduced. The contact between the carbon brush 3 and the surface of the commutator 14 is improved, and the balance of the carbon brush elastic force 29 is also improved, so that the sparks generated when the carbon brush 3 and the commutator 14 rub or commutate during the operation of the motor are reduced.

Compared with the traditional carbon brush 3 (as shown in fig. 10 and 11), the utility model discloses in with (as shown in fig. 12 and 13), vacate the space for 4 arms of torsional spring in the plastic cover 9, cooperate the angle of bending of second torsional spring arm bending 27 to with the torsional spring effect of 4 arms of torsional spring and carbon brush 3 and the power 31 immigration of carbon brush more be close to the axis of carbon brush 3, carbon brush afterbody slot one side design has the opening 23 of V type.

Referring to fig. 16 and 17, the winding of the present invention is arranged in the following manner: one side of the second and third (two adjacent) outer windings 16W is respectively placed in the two core slots 28 spanned by each outer winding 16W, the other side of the two outer windings 16W respectively spans the two core slots 28 towards two sides, and so on for the arrangement of all the outer windings 16W. An inner winding 16N is symmetrically arranged on one side opposite to each outer winding 16W, the arrangement mode of the inner winding 16N is the same as that of the outer winding 16W, and the specifications of the inner winding and the outer winding are the same; each pair of opposing one of the outer windings 16W-1 and one of the inner windings 16N-1 are connected in parallel with each other as shown in fig. 18. For the conventional 5-tooth core, if the pitch of the winding 16 is greater than one slot, the adjacent windings 16 after the lap winding cannot be made uniform in size, resulting in non-uniformity of the resistance of the winding 16 and an increase in the unbalance amount of the rotor. The utility model discloses in, the symmetry of slot winding 16 is striden to the use of equalizer line 34 and rotor for the resistance of winding 16 or the inter-chip resistance of rotor are more even, and the balance of rotor also is improved.

Referring to fig. 18, the hooks of opposing segments of commutator 14 are connected by a short circuited equalizer 34, the total number of equalizer 34 being one-half of 10 for commutator 14 hooks. In addition, when a rotor is wound, a hook of the commutator 14 hung on the start line is a hook of the tail line at the end of the commutator 14, and a short-circuit equalizing line 34 is added, so that 3 enamelled wires exist on the start hook of the commutator, which is inconvenient for spot welding; therefore the utility model discloses end the wire winding on the tail hook 36 relative and the level is unanimous with the start hook 35 of commutator 14 to ensure that the enameled wire quantity of connecting can reduce to two or one on every commutator 14 hook, reduce the degree of difficulty of spot welding, improve the uniformity and the quality of spot welding.

Referring to fig. 19, the tail of the last outer winding 16W is hooked on the tail hook 36 of the commutator 14 and then terminated by being connected to the oppositely disposed start hook 35 of the commutator 14 via the equalizer 34.

Claims (6)

1. A700 # micro ferrite permanent magnet direct current motor is characterized in that 4 magnetic shoes are uniformly arranged in the inner circumferential direction of a 700 # housing with the outer diameter of phi 42.2mm, and the N poles and the S poles of the magnetic shoes are alternately distributed; on the cross section of the outer cylinder of the motor shell, a pair of carbon brushes is distributed in 90 degrees, the central lines of the carbon brushes are respectively aligned with the central lines of the two opposite poles of the magnetic shoe, and the outer ends of the carbon brushes are provided with torsion springs; a rotor is rotatably arranged on the axis of the shell, a main shaft capable of rotating is arranged in the center of the rotor, an iron core and a commutator are arranged on the main shaft, and a commutator hook used for welding an enameled wire end of a winding is arranged on each segment of the commutator; the iron core is characterized in that the number of the iron core slots is 10, and the number of the commutator segments is the same as that of the iron core slots; the center line of each commutator hook is aligned with the center line of each core groove in the circumferential direction centered on the main shaft.

2. The miniature ferrite permanent magnet direct current motor of claim 700 wherein the hooks on the commutator segments are connected by only one equalizer, the total number of equalizers being half of the number of commutator segments.

3. The miniature ferrite permanent magnet direct current motor as claimed in claim 1, wherein the commutator hook comprises a start hook and a tail hook which are oppositely arranged on the commutator segment, and the start hook and the tail hook are mutually connected by an equalizing line.

4. The miniature ferrite permanent magnet direct current motor of claim 1, wherein a single winding pitch spans three slots of the rotor, the adjacent windings in the front and back are symmetrically arranged, and an inner winding spanning three slots of the rotor is connected in parallel with an outer winding spanning three slots of the rotor.

5. The miniature ferrite permanent magnet direct current motor of claim 1 wherein the rotor has an outer diameter 10% to 15% larger than conventional 5-tooth and 6-tooth rotors.

6. The miniature No. 700 ferrite permanent magnet direct current motor as claimed in claim 1, wherein the torsion spring is provided with two bends, and a second torsion spring arm bend is added between the traditional first torsion spring arm bend and the carbon brush tail part to reduce the included angle between the torsion spring arm and the carbon brush tail part; correspondingly, a V-shaped notch is designed at the tail end of the carbon brush and used for accommodating the end part of the torsion spring.

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