JPS6210104B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a plurality of n coils C ₁ , C ₂ ……
A plurality of n magnetic poles A ₁ each wrapped with C _o ,
A ₂ ...... An armature core consisting of A _o , a shaft extending from the armature core, and at least a coil C _i (i=1, 2...
. . . n) Regarding the improvement of a DC motor comprising an armature having a commutator facing a brush having commutator pieces B _i electrically connected to one end thereof, in particular:
The coil C _i is repeatedly energized and de-energized, thereby suppressing the spike-like voltage that occurs as noise when the coil C _i is switched between energized and de-energized.

Conventionally, in such a DC motor, a spike-like voltage absorbing element such as a capacitor or a varistor is connected electrically in parallel with the coil C _i , whereby the coil C _{i is repeatedly energized and de-energized, thereby causing the coil C i} to repeatedly energize and de-energize. A configuration has been proposed that suppresses the spike-like voltage that occurs as noise when switching between energization and de-energization of C _i , but it has not been able to sufficiently suppress the spike-like voltage.

Therefore, the present invention proposes a novel DC motor that can sufficiently suppress the spike-like voltage that occurs as noise when switching between energization and de-energization of coil C _i due to repeated energization and de-energization of coil C _i . This will become clear from the following detailed description of embodiments of the invention with reference to the drawings.

In the figure, 1 indicates the DC motor as a whole, and as usual, there are a plurality of n coils, for example, three coils C ₁ ,
Three magnetic poles each wrapped with C ₂ and C ₃
An armature core 2 consisting of A ₁ , A ₂ and A ₃ , a shaft 3 extending from the armature core 2, one end of coils C ₃ and C ₁ mounted on this shaft 3, and one end of coil C ₁ and one end of coil C ₂ , and coil C ₂
and an armature 5 having an opposing commutator 4 of brushes G1 and G2 having three commutator pieces B ₁ B ₂ and B ₃ electrically connected to the other end of C ₃ .
(rotor) and a stator 6 having an inner peripheral surface magnetized with N and S magnets.

In the embodiment of the present invention, in such a DC motor 1, slip rings H1 and H2 are provided on the shaft 3 of the armature 5, with spike-shaped voltage absorbing brushes K1 and K2 facing each other, respectively,
Although not shown in FIG. 1, between the slip ring H1 and the commutator piece B _i of the commutator 4, as shown in the electrical equivalent circuit of FIG. The element D _i (which has the voltage-current characteristic of a diode such that the positive rising voltage (this is referred to as V _D ) is larger than the negative rising voltage) slips H1 toward the commutator bar B _i side.
The slip ring H2 and the commutator piece B i are electrically connected with the polarity such that the current flows from the side, and the slip ring H2 is connected from the commutator piece _{B i side} to the slip ring H2.
A unidirectional element similarly made of a diode (having the voltage-current characteristics of a diode in which the positive rising voltage is smaller than the negative rising voltage (this is designated as _VE )) ) E _i
have a configuration in which they are electrically connected.

The above is the configuration of the embodiment of the DC motor according to the present invention.

According to the DC motor according to the present invention having such a configuration, as is clear from _{FIG .}
One end of the unidirectional element D _i is electrically connected to the side through a slip ring H1 and a brush K1 that is in contact with the slip ring H1, with a polarity that allows current to flow in from the outside, and a slip ring from the commutator piece B _i side. ring h2
and another unidirectional element E _i with a polarity that causes the current to flow outside through the brush K2 that is in contact with the brush K2.
One end of the commutator bar is electrically connected to the other end of the commutator bar.
One end of coils C ₃ and C ₁ , the other end of coil C ₁ and one end of coil C ₂ , and the other ends of coils C ₂ and C 3 are electrically connected to B _{1 ,} B ₂ and B ₃ , respectively. .

Therefore, the other ends of the unidirectional elements Di and Ei are
A negative terminal of a DC power supply (not shown) connected, for example, between the brushes G1 and G2 facing the commutator 4 via the slip rings H1 and H2, respectively, and the brushes K1 and K2 facing the same, respectively. and a positive polarity terminal (none of which is shown) or first and second external power supply terminals from which potentials approximately equal to those obtained at the negative and positive terminals are electrically connected. , even with such a connection, the voltage of a DC power source (not shown) connected between the brushes G1 and G2 facing the commutator 4 as unidirectional elements D _i and E _i
If a positive _rising voltage V _D and a negative rising voltage V _E are used, each having an absolute value larger than the absolute value of the coil C _i (commutator piece B _i When the connected side) is connected to the negative terminal of the DC power supply, not only the unidirectional element E _i but also the unidirectional element D _i are biased in the opposite direction. Further, when one end of the coil C _i is connected to the positive terminal of the DC power supply, not only the unidirectional element D _i but also the unidirectional element E _i is biased in the opposite direction. Therefore, the unidirectional elements D _i and E _i receive current from the DC power supply even when one end of the coil C _i is connected to the negative polarity terminal of the DC power supply. (There is no problem in the coil C _i repeating energization and de-energization.) When the coil C _i is switched between energization and de-energization, a spike voltage occurs in the coil C _i , A negative polarity voltage whose absolute value is larger than the absolute value of the positive rising voltage V _D of the unidirectional element D _i (the side connected to the commutator piece B _i of the coil C _i is set as negative polarity) When the unidirectional element D _i is energized and the spike-like voltage is a positive polarity voltage having an absolute value larger than the absolute value of the negative rising voltage V _E of the unidirectional element E _i When obtained, the unidirectional element E _i is energized so that the spike-like voltage is a negative polarity voltage with an absolute value larger than the absolute value of the positive rising voltage V _D of the unidirectional element D _i and the unidirectional element E i is energized. When obtained with a positive polarity voltage having a larger absolute value than the absolute value of the negative rising voltage V _E of the element E _i , a positive rising voltage V _D and a negative rising voltage in the negative direction and positive direction of the spike voltage, respectively. For voltages higher than V _E , each unidirectional element D
_i and E _i , and thus the spike-like voltage is absorbed by the positive rising voltage V D of the unidirectional element D _i and the negative rising voltage V _D of the unidirectional element E _i , respectively.
suppressed by _E.

Therefore, the absolute values of the positive rising voltage V _D and negative rising voltage V _E of the unidirectional elements D _i and E _i are larger than the absolute value of the voltage V ₀ of the DC power supply, but the voltage By using a voltage close to the absolute value of V ₀ , the spike-like voltage described above can be suppressed to about the absolute value of the voltage of the DC power supply.

As described above, according to the embodiment of the present invention described above, the spike-like voltage generated as noise when the coil C _i is switched between energization and de-energization due to repeated energization and de-energization of the coil C _i is removed from the commutator 4. can effectively suppress the voltage of the DC power supply connected between the brushes G1 and G2 facing each other to about the absolute value, and
This suppressing effect can be suppressed by the commutator pieces B _i of the commutator 4.
One end of the unidirectional element D _i is electrically connected with a polarity that allows a current to flow into the commutator piece B _i side from the outside, and a polarity that allows a current to flow out from the commutator piece B _i side to the outside. One end of the unidirectional element E _i is electrically connected, while the other ends of the unidirectional elements D _i and E _i are each electrically connected to an external power supply terminal. It has the great feature that it can be obtained by configuration.

In the above description, slip rings H1 and H2 are provided on the shaft 3 of the armature 5 and the brushes K1 and K2 are in contact with each _{other .} By connecting one end of the commutator element 4 on the side opposite to the commutator element B _i side, these unidirectional elements Di and
Although we have described the case in which one end of Ei is electrically connected to the first and second external power supply terminals, the shaft 3 and the bearing (not shown) supporting it are electrically conductive. If the slip ring H1 or H2 is omitted, and one end of the unidirectional element E _i or D _i is connected to the slip ring H2 or H1, the unidirectional element D _i or E _i One end may be connected to the shaft 3, and, with respect to the unidirectional element D _i or E _i , one end thereof may be electrically connected to the first or second external power terminal via a bearing. can.

Further, in the above description, one end of the coils C ₁ and C ₃ , the other end of the coil C ₁ and one end of the coil C ₂ , and the other ends of the coils C ₂ and C ₃ are electrically connected to the commutator pieces of the commutator 4. An embodiment has been described in which the present invention is applied to a DC motor in which the coils are connected to B ₁ , B _{2 and} B ₃ in a so _- called _△ shape. The present invention is also applied to a DC motor in which the coils are electrically connected to the commutator pieces B1, _B2 , and _B3 of the commutator 4, and the other ends are connected to each other, so that the coils are connected in a so-called Y shape. It is obvious that it can be done.

Further, in the above description, an embodiment of the present invention is described in which the present invention is applied to a so-called 35-type DC motor, but the present invention can also be generally applied to an N-pole type DC motor, and other , various modifications and changes may be made without departing from the spirit of the invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing an embodiment of a DC motor to which the present invention is applied. FIG. 2 is its electrical equivalent circuit diagram. 1...DC motor, _C1 ~ _C3 ...Coil, _A1 ~
A ₂ ...Magnetic pole, 2...Armature core, 3...Shaft, 4
... Commutator, B ₁ to _{B 3} ... Commutator piece, G ₁ , G ₂ ...
Brush, 5... Armature, 6... Stator, H1, H2
...Slip ring, K1, K2...Brush, D ₁
~D ₃ , E ₁ ~ _{E 3} ... Unidirectional element.

Claims (1)

[Scope of Claims] 1. A plurality of n magnetic poles A _{1 , A 2 ...... around which a plurality of n coils C 1 , C 2 ...... C o} are respectively wound.
...An armature core consisting of A _o , a shaft extending from the armature core, and at least the above-mentioned coil C _i (i=1, 2...n) mounted on the shaft.
In a DC motor including an armature having a brush and a commutator in contact with each other, the brush has a commutator piece B _i electrically connected to one end thereof, and the commutator piece B _i of the commutator is provided with the commutator piece B i of the commutator. B _i
One end of the first unidirectional element D _i is electrically connected with a polarity such that a current flows into the side from the outside, and a second unidirectional element has a polarity such that a current flows out from the commutator piece B _i side to the outside. One end of the element E _i is electrically connected, and the other ends of the first and second unidirectional elements D _i and E _i are electrically connected to the first and second external power terminals, respectively. A DC motor characterized by the following features: