JP4395974B2 - DC motor with brush - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a brushed DC motor in which a coil is concentratedly wound around an armature core.
[0002]
[Prior art]
As an example of a conventional concentrated winding brushed DC motor, there is an 8-pole 9-slot DC motor disclosed in Japanese Patent Publication No. 61-47062. Since this DC motor has an odd number of slots (number of coils), the force acting on the armature (rotor) does not become a couple. For this reason, a radial force acts on the armature in addition to the rotational force, and the radial force changes direction with the rotation of the armature, so that the rotating armature is in a swinging state, There is a drawback that vibration occurs.
[0003]
Therefore, as shown in JP-A-11-69747, a 4-pole 6-slot DC motor has been proposed. Since this 4-pole 6-slot DC motor has an even number of slots, the force acting on the armature becomes a couple, and there is an advantage that the armature rotates smoothly without causing a swing.
[0004]
[Problems to be solved by the invention]
However, the 4-pole 6-slot DC motor disclosed in Japanese Patent Application Laid-Open No. 11-69747 has a drawback that the life of the brush is reduced due to its large inductance. That is, in the 4-pole 6-slot DC motor of this publication, as shown in FIG. 5, the current flowing between the brush 1 (+ B) and the brush 2 (GND) has two coils 3 as shown by arrows. Flows through a series circuit of coils connected in series. As described above, when the current flows through the coil series circuit, the inductance of the circuit increases, so that the reactance voltage induced in the circuit increases, and a spark is easily generated between the adjacent commutator segments 4. Therefore, the brush is easily worn by the spark. In general, as the inductance (reactance voltage) increases, the life of the brushes 1 and 2 decreases. Therefore, in order to extend the life of the brushes 1 and 2, it is necessary to reduce the inductance.
[0005]
The present invention has been made in consideration of such circumstances. Therefore, the object of the present invention is to reduce the inductance of the brushed DC motor and extend the life of the brush, and realize smooth rotation with less vibration. It is an object of the present invention to provide a brushed direct current motor.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, in the brushed DC motor according to claim 1 of the present invention, the number of magnetic poles m of the magnet is an even number, and the number of slots n of the armature core is two more than the number of magnetic poles m (n = m + 2), the coil is concentrated on the armature core, the number of commutator segments s is s = (m / 2) × n = (m / 2) × (m + 2), and the brush width is the commutator segment. And the brush interval is one segment of the commutator segment , and all the coils energized between the brushes are connected to the commutator segment and have a brush configuration. It is a feature . When the present invention is applied to a 4-pole 6-slot DC motor, for example, as shown in FIG. 4, the current flowing between the brush (+ B) and the brush (GND) flows through four coils. The energizing coils are all arranged in parallel between the brush (+ B) and the brush (GND), and a plurality of energizing coils are not arranged in series between the brush (+ B) and the brush (GND). . For this reason, the inductance (reactance voltage) of the DC motor is reduced, and the life of the brush can be extended. Moreover, since the number of slots in the armature core is an even number, the force acting on the armature becomes a couple, and the rotating armature does not sway, and smooth rotation with less vibration can be realized.
[0007]
In this case, as described in claim 2, when the coil is concentratedly wound around the armature core, one magnet wire is connected to the riser connected to the commutator segment, and each salient pole of the armature core is in a predetermined order. After winding all the windings with a single stroke, the magnet wire that directly connects the predetermined risers may be cut. Thus, if the coil is concentratedly wound with a single stroke with one magnet wire, the winding work can be performed very efficiently, the mass productivity can be improved, and the demand for cost reduction can be satisfied.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment in which the present invention is applied to a 4-pole 6-slot DC motor will be described below with reference to FIGS. A total of four N-pole and S-pole magnets 12 are alternately attached to the inner peripheral portion of a cylindrical yoke 11 that also serves as a motor housing to form a four-pole field. An armature 13 is provided on the inner peripheral side of the magnet 12 so as to be rotatable about a rotation shaft 14. As will be described later, the coil 16 is concentrated and wound around six salient poles A to F formed radially on the armature core 15 of the armature 13 with a single stroke. In this case, the number n of the slots 17 of the armature 13 is six, which is two more than the number of magnetic poles m (= 4) of the magnet 12.
[0009]
Commutator segments S <b> 1 to S <b> 12 (see FIG. 2) are provided radially around the rotating shaft 14 on the axial end surface of the armature core 15. In this case, the number s of commutator segments S1 to S12 is set to 12 from the following equation.
s = (m / 2) × n = (4/2) × 6 = 12
m: Number of magnetic poles of magnet 12 n: Number of slots 17
Of the twelve commutator segments S1 to S12, odd-numbered commutator segments S1, S3, S5, S7, S9, and S11 are provided with risers 18 for connecting coils 16 respectively. The odd-numbered commutator segments S1, S3, S5, S7, S9, and S11 provided with the riser 18 are connected to the coil 16, but the even-numbered commutator segment S2, not provided with the riser 18. The coils 16 are not connected to S4, S6, S8, S10, and S12, and are in an open state.
[0011]
In this case, when the coil 16 is concentratedly wound around the armature core 15, the riser in which one magnet wire 19 is connected to each commutator segment S1, S3,... In the winding sequence shown in FIG. 18 is wound around each of the salient poles A to F of the armature core 15 with a single stroke in a predetermined order. After all the windings are finished, the magnet wire 19 that directly connects between the predetermined risers 16 is cut. .
[0012]
For example, in the winding method (part 1) shown in FIG. 2, the winding operation starts from the riser connection of the first commutator segment S1, and the winding of the salient pole B → the riser connection of the fifth commutator segment S5. → winding of salient pole D → riser connection of ninth commutator segment S9 → winding of salient pole F → riser connection of first commutator segment S1 → riser connection of seventh commutator segment S7 → salient pole Winding of C → Riser connection of third commutator segment S3 → Winding of salient pole A → Riser connection of eleventh commutator segment S11 → Winding of salient pole E → Riser of seventh commutator segment S7 Connection → riser connection of the ninth commutator segment S9 → riser connection of the third commutator segment S3 → riser connection of the fifth commutator segment S5 → riser connection of the eleventh commutator segment S11 The magnet wire 19 of the present will be wound in sequentially to each salient pole to F. After all the winding operations are completed, the magnet wire 19 that directly connects the risers 18 of the commutator segments S3 and S5 is cut, and the magnet wire 19 that directly connects the risers 18 of the commutator segments S7 and S9 is removed. Disconnect.
[0013]
On the other hand, in the winding method (part 2) shown in FIG. 3, the winding work is started from the riser connection of the fifth commutator segment S5, and the riser connection of the eleventh commutator segment S11 → the winding of the salient pole A → Riser connection of third commutator segment S3 → Winding of salient pole C → Riser connection of seventh commutator segment S7 → Riser connection of first commutator segment S1 → Winding of salient pole F → 9th The riser connection of the commutator segment S9 → the winding of the salient pole D → the riser connection of the fifth commutator segment S5 → the winding of the salient pole B → the riser connection of the first commutator segment S1 → the seventh commutator Riser connection of segment S7 → winding of salient pole E → riser connection of eleventh commutator segment S11 → riser connection of ninth commutator segment S9 → riser connection of third commutator segment S3 in order of 1 Going to winding the magnet wire 19 in order to each salient pole A~F. Then, after all the winding operations are completed, the magnet wire 19 that directly connects the risers 18 of the commutator segments S9 and S11 is cut.
[0014]
The widths of the two brushes 20 and 21 (+ B, GND) that are in sliding contact with any one of the commutator segments S1 to S12 are respectively formed in two segments of the commutator segment, and the two brushes 20, 21 (+ B , GND) is set to one commutator segment.
[0015]
The six coils 16 wound around the salient poles A to F of the brushed DC motor of the present embodiment configured as described above are odd-numbered rectifiers provided with risers 18 as shown in FIG. One each is connected between the child segments S1, S3, S5, S7, S9, S11. That is, the salient pole A coil 16 (hereinafter referred to as “coil A”) is connected between the commutator segments S11 and S3, and the salient pole C coil 16 (hereinafter referred to as “coil C”) between the commutator segments S3 and S7. And a coil 16 of salient pole D (hereinafter referred to as “coil D”) is connected between commutator segments S5 and S9, and coil 16 of salient pole F is connected between commutator segments S9 and S1. (Hereinafter referred to as “coil F”) is connected, coil 16 of salient pole E (hereinafter referred to as “coil E”) is connected between commutator segments S11 and S7, and between commutator segments S5 and S1. The coil 16 of the salient pole B (hereinafter referred to as “coil B”) is connected.
[0016]
When the positional relationship between the two brushes 20, 21 (+ B, GND) and the commutator segments S1 to S12 is as shown in FIGS. 2 and 3, one brush 20 (+ B) has three commutators. The segments 20 slidably contact the segments S 10, S 11, and S 12, but the commutator segments S 10 and S 12 on both sides are not connected to the coil 16, so the brush 20 (+ B) is energized to the coil 16 only by the intermediate commutator segment S 11. To do. The other brush 21 (GND) is in sliding contact with the three commutator segments S7, S8, and S9. Of these, the intermediate commutator segment S8 is not connected to the coil 16, so the brush 21 (GND) Conducts the coil 16 to GND (ground) via the commutator segments S7, S9 on both sides.
[0017]
As a result, as indicated by arrows in FIG. 4, the current flowing between the brush 20 (+ B) and the brush 21 (GND) is four coils E, A, D, B out of the six coils A to F. The four energizing coils E, A, D, and B are all arranged in parallel between the brush 20 (+ B) and the brush 21 (GND), and the brush 20 (+ B) and the brush 21 (GND). A plurality of current-carrying coils are not arranged in series. For this reason, the inductance (reactance voltage) of the DC motor is reduced, it is difficult for sparks to occur between adjacent commutator segments, and the life of the brushes 20 and 21 can be extended. Moreover, since the number of the slots 17 in the armature core 15 is an even number, the force acting on the armature 13 becomes a couple, and the rotating armature 13 does not run around and realizes smooth rotation with little vibration. be able to.
[0018]
Moreover, in the present embodiment, when the coil 16 is concentratedly wound around the armature core 15, one magnet wire 19 is connected to each commutator segment S1, S3 in the order shown in FIG. .. Are wound around the salient poles A to F of the armature core 15 in a predetermined order while being connected to the riser 18 connected to..., And after all the windings are finished, the predetermined risers 16 are directly connected. Since the magnet wire 19 is cut, the winding work can be performed very efficiently, the mass productivity can be improved, and the demand for cost reduction can be satisfied. However, the present invention is not limited to the configuration in which concentrated winding is performed by one stroke with one magnet wire 19, and concentrated winding may be performed by a method other than one stroke writing. The objective can be fully achieved.
[0019]
The present embodiment described above is an embodiment in which the present invention is applied to a 4-pole 6-slot DC motor, but the number of magnetic poles m and the number of slots n may be changed as appropriate. , The number of slots n is increased by 2 from the number of magnetic poles (n = m + 2), the coil is concentratedly wound around the armature core, and the number of commutator segments s is set to s = (m / 2) × n = (M / 2) × (m + 2), the brush width may be two segments of the commutator segment, and the brush interval may be one segment of the commutator segment. For example, the present invention may be applied to a 6-pole 8-slot DC motor. In this case, the number of commutator segments s is s = (m / 2) × n = (6/2) × 8 = 24. Just do it.
[0020]
In the configuration example of FIG. 1, the commutator segments S <b> 1 to S <b> 12 are arranged in a radial plane around the rotating shaft 14, but the commutator segments S <b> 1 to S <b> 12 are arranged in a cylindrical shape around the rotating shaft 14. A brush may be arranged around the outside.
[Brief description of the drawings]
FIG. 1 is a side view of a main part of a DC motor showing an embodiment of the present invention. FIG. 2 is a developed winding diagram illustrating a winding method (part 1). FIG. 3 is a winding method (part 2). Developed winding diagram to explain [Fig. 4] Electric circuit diagram of DC motor [Fig. 5] Electric circuit diagram of conventional DC motor [Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Yoke, 12 ... Magnet, 13 ... Armature, 14 ... Rotating shaft, 15 ... Armature core, 16 ... Coil, 17 ... Slot, 18 ... Riser, 19 ... Magnet wire, 20, 21 ... Brush, AF ... salient poles, S1-S12 ... commutator segments.

Claims (2)

The number m of magnetic poles of the magnet is an even number, the number of slots n of the armature core is increased by 2 from the number of magnetic poles m (n = m + 2), the coil is concentratedly wound around the armature core, and the number of commutator segments s is set. S = (m / 2) × n, the brush width is two segments of the commutator segment, the brush interval is one segment of the commutator segment , and all the coils that are energized between the brushes A brushed DC motor having a connection to the commutator segment and a brush configuration to form a parallel circuit .   The coil is wound in a predetermined order on each salient pole of the armature core while connecting one magnet wire to a riser connected to the commutator segment, and after all the windings are finished 2. The brushed DC motor according to claim 1, wherein a magnet wire directly connecting between predetermined risers is cut and formed.

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