JP2006197754A - Rotor and motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor and a motor wherein spark discharge that occurs in a rectifying mechanism can be reduced even when drive voltage is high. <P>SOLUTION: A chip capacitor 1 is connected between adjoining commutators 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rotor and a motor, and more particularly to a rotor and a motor having a rectifying mechanism.

  The DC motor has excellent rotation characteristics as a control motor, such as a large starting torque, linear rotation characteristics with respect to changes in applied voltage, and linearity of output torque with respect to input current. Due to the commutator, spark discharge occurred between the brush and the commutator during rectification.

In order to remove this spark discharge, conventionally, a ring varistor 9 as shown in FIG. 6 has been connected to the commutator 4 with solder 5 as shown in FIGS. 7A to 7D (see Patent Document 1). In this case, an equivalent circuit of the armature (rotor) is as shown in FIG. If the ring varistor 9 is not used, the equivalent circuit of the rotor is as shown in FIG.
JP 09-308191 A

  However, the rated voltage of the ring varistor is generally 100 V or less due to the physical properties of the material, and cannot be used for a DC motor with a driving voltage of 100 V DC or more.

  Further, in a DC motor having a driving voltage of DC 100V or more, the winding inductance is larger than that of a DC motor having a driving voltage of less than DC 100V, so that spark discharge is likely to occur. Further, as the drive voltage increases, the amount of spark discharge increases and the commutator segments may be short-circuited.

  Therefore, an object of the present invention is to provide a rotor and a motor that can reduce spark discharge generated by a rectifying mechanism even when the drive voltage is high.

  In order to achieve the above object, according to the present invention, in a rotor having a plurality of commutators, a capacitor is connected between the commutators.

  ADVANTAGE OF THE INVENTION According to this invention, even if a drive voltage is high, it becomes possible to provide the rotor and motor which can reduce the spark discharge which generate | occur | produces with a rectification | straightening mechanism.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the first to third embodiments, it is assumed that the number of slots (that is, the number of magnetic poles) of the rotor is “5”, but the present invention is not limited to this. In the first to third embodiments, a rotor of a DC motor with a commutator (commutator) is assumed. However, it may be applied to an AC / DC universal motor with a commutator (commutator). Is possible.

[First Embodiment]
In the rotor according to the first embodiment, as shown in FIGS. 1 to 3, adjacent segments of the commutator 4 fitted to the rotating shaft 8 are connected by the chip capacitor 1.

  That is, as shown in FIG. 1, five chip capacitors 1 are soldered to the circuit board 2 with the solder 3, and the circuit board 2 is soldered to the commutator 4 as shown in FIGS. As shown in FIG. 3, adjacent segments of the commutator 4 are connected to each other by the chip capacitor 1.

  In the above description, the commutator 4 including a plurality of segments is regarded as one commutator. However, when these segments are regarded as one commutator, the commutator 4 is configured by a plurality of commutators. Become.

  When adjacent segments of the commutator 4 are connected by the chip capacitor 1 as described above, the electric charge to be discharged between the rectifying mechanism, that is, between the segments of the brush 6 and the commutator 4 (slit portion) is stored in the chip capacitor 1. Therefore, spark discharge and electric noise are reduced.

  In this case, the electric charge to be discharged increases as the driving voltage increases, but by selecting the chip capacitor 1 having a capacitance according to the driving voltage, a spark discharge generated by the rectifying mechanism even when the driving voltage is high. And electrical noise can be reduced.

  The chip capacitor 1 preferably has a rated voltage of 150 V or more and a capacitance of 0.001 to 0.1 μF.

[Second Embodiment]
In the rotor according to the second embodiment, as shown in FIG. 4, adjacent segments of the commutator 4 are connected by the chip capacitor 1 and the chip resistor 7 that are connected in parallel to each other.

  When the chip capacitor 1 and the chip resistor 7 are used in this way, spark discharge and electrical noise are caused by the voltage drop action of the chip resistor 7 as compared with the case where only the chip capacitor 1 is used as in the first embodiment. The effect of reducing is increased.

[Third Embodiment]
In the conventional motor, the number of commutator segments (that is, the number of commutators) is the same as the number of slots (that is, the number of magnetic poles) of the rotor. For example, when the number of slots of the rotor is “5”, As shown, the number of commutator segments was also “5”.

  On the other hand, in the third embodiment, the number of commutator segments is twice the number of rotor slots. That is, as shown in FIG. 5, when the number of slots of the rotor is “5”, the number of segments of the commutator is set to “10”.

  In the third embodiment, the number of turns of one coil of the rotor is set to “½”. That is, if the number of turns of one coil of the rotor is “T” when the number of slots of the rotor and the number of segments of the commutator are both “5” (conventional case in FIG. 10), the number of slots of the rotor is “5”. ”And the number of commutator segments is“ 10 ”(in the case of the third embodiment in FIG. 5), the number of turns of one coil is“ T / 2 ”.

  In other words, in the third embodiment, one magnetic pole is obtained by setting the number of turns of each coil to “½” in accordance with the number of commutator segments, that is, the number of coils of the rotor being doubled. The number of turns of the winning coil is not changed, and the motor rotation characteristics are not changed.

  Since the inductance of the coil is proportional to the square of the number of turns, when the number of turns of one coil of the rotor is “½” as in the third embodiment, the inductance of one coil is ¼. It becomes. That is, if the inductance of one coil in the case of FIG. 10 is H, the inductance of one coil in the case of FIG. 5 is H / 4.

  Thus, in the third embodiment, since the inductance of one coil is reduced, spark discharge and electrical noise generated by the rectifying mechanism are reduced even when the drive voltage is high.

  As described above, in the rotors according to the first to third embodiments, it is possible to reduce spark discharge and electrical noise generated by the rectifying mechanism even when the drive voltage is high. Therefore, even when the driving voltage of the motor is high, it is possible to prevent the commutators from being short-circuited, thereby improving the reliability of the rotor and the motor using this rotor and extending the life.

  The present invention is not limited to the first to third embodiments, and can be applied to, for example, a slotless rotor having no slot or a motor using the rotor. It is also possible to use capacitors other than chip capacitors and resistors other than chip resistors.

  Furthermore, in the third embodiment, the number of commutator segments, that is, the number of commutators, can be set to a positive integer multiple other than twice the number of magnetic poles of the rotor, such as three times, four times, five times, etc. It is. In this case, by setting the number of turns of one coil corresponding to each commutator to 1/3, 1/4, 1/5,..., The motor rotation characteristics can be prevented from changing.

It is a figure which shows the state which attached the chip capacitor to the circuit board (1st Embodiment). It is a figure which shows the rotor which attached the circuit board of FIG. It is a figure which shows the equivalent circuit of the rotor which concerns on the 1st Embodiment of this invention. It is a figure which shows the equivalent circuit of the rotor which concerns on the 2nd Embodiment of this invention. It is a figure which shows the coil wiring state of the rotor which concerns on the 3rd Embodiment of this invention. It is a figure which shows the ring varistor conventionally used. It is a figure which shows the rotor using the conventional ring varistor. It is a figure which shows the equivalent circuit of the rotor at the time of using the conventional ring varistor. It is a figure which shows the equivalent circuit of the rotor when not using the conventional ring varistor. It is a figure which shows the coil wiring state of the conventional rotor.

Explanation of symbols

1 ... chip capacitor 4 ... commutator 6 ... brush 7 ... chip resistor

Claims (5)

  A rotor having a plurality of commutators, wherein a capacitor is connected between the commutators.   The rotor according to claim 1, wherein a resistor is connected in parallel to the capacitor.   A rotor having a commutator whose number is n (n = positive integer) times the number of magnetic poles of the rotor.   The rotor according to claim 3, wherein the number of turns of each coil corresponding to the commutator is 1 / n of the number of turns when the number of commutators is the same as the number of magnetic poles of the rotor.   The motor which has a rotor of any one of Claims 1-4.

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