JP2016036206A - Dc electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress reduction in interlinkage flux of a coil, and suppress increase in inductance of the coil.SOLUTION: A DC electric motor 10 comprises: a stator 16 having a magnet 14; and a rotor 18 having a rotation shaft 30, a rotor core 32, a commutator 34, and a plurality of coils 36. The rotor core 32 includes: a plurality of main pole parts 40 extending in a radial direction and arranged in a circumferential direction at an interval; and a plurality of auxiliary pole parts 42 extending in the radial direction and arranged between the respective main pole parts 40. The commutator 34 includes a plurality of segments 34A to which a brush is slidably contacted. The coils 36 are formed by winding a plurality of windings whose terminal parts are respectively connected with different pairs of segments 34A. The plurality of coils 36 are respectively provided around each main pole part 40.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a DC motor.

  In Patent Document 1 and Patent Document 2 below, a plurality of main pole portions (main salient pole portions, main poles) in which a coil is formed along the outer periphery by winding a conductive winding, An electric motor including an armature having an auxiliary pole portion (auxiliary salient pole portion, auxiliary pole) provided between the main pole portion and the other main pole portion is disclosed.

Japanese Patent Publication No. 3-243154 Japanese Utility Model Publication No. 3-97372

  By the way, in a DC motor configured to include an armature having a main pole portion and an auxiliary pole portion, a single coil is formed around the main pole portion by winding the winding around the main pole portion. Therefore, the interlinkage magnetic flux of the coil is likely to decrease and the inductance of the coil is easily increased.

  In consideration of the above facts, the present invention has an object to obtain a DC motor that can suppress a decrease in the flux linkage of a coil and suppress an increase in the inductance of the coil.

  The DC motor according to claim 1 is fixed to a stator having a magnet and a rotation shaft provided radially inward of the stator, and extends in the radial direction and is arranged at intervals along the circumferential direction. A rotor core having a plurality of main pole portions and a plurality of complementary pole portions extending in the radial direction and disposed between each of the main pole portions, and a plurality of brush cores fixed to the rotating shaft and in sliding contact with the brush And a plurality of windings connected to a pair of segments each having a different terminal portion, and a plurality of windings respectively provided around each of the main pole portions. And a rotor having a coil.

  According to the DC motor of the first aspect, the energization of the plurality of coils is switched by the brush being in sliding contact with each segment of the commutator. Thereby, the magnetic field generated in the rotor core is switched, and the rotor rotates relative to the stator by the magnetic field and the magnetic field of the stator magnet.

  Moreover, in this invention, the cogging torque and torque ripple of a DC motor can be reduced by providing an auxiliary pole part between main pole parts.

  Here, in the DC motor, a plurality of coils are provided around each main pole portion. In other words, two or more coils are provided around one main pole portion. Thereby, compared with the structure by which one coil is provided around one pole part, the fall of a winding coefficient is suppressed and by extension, it can suppress that the linkage flux of a coil reduces. . Further, as compared with the case where a single coil having the same number of turns is provided around the main pole portion, it is possible to suppress the number of turns of one coil from decreasing and the inductance of the coil from increasing.

  In addition to this, in the DC motor, two or more coils provided around one main pole portion are connected to a pair of different segments. Thereby, the energy at the time of switching the energization to the coil due to the brush being in sliding contact with each segment can be reduced, and consequently the life of the brush can be prevented from being reduced. In addition, noise during switching of energization to the coil can be reduced.

  The DC motor according to claim 2 is the DC motor according to claim 1, wherein the number of the main pole portions is T, the number of pole pairs of the magnets constituting a part of the stator is P, and the number of the segments. Is set to a number obtained by T × P × n (n = 1, 2, 3,...).

  According to the DC motor according to claim 2, by setting the number of segments to the above number, it is possible to suppress an increase in the inductance of the coil while suppressing a decrease in the flux linkage of the coil. it can.

1 is an exploded perspective view showing a DC motor according to a first embodiment. It is a plane sectional view showing the direct-current motor concerning a 1st embodiment. It is a schematic diagram which shows the connection relationship between each coil and each segment of a commutator. It is a plane sectional view corresponding to Drawing 2 showing a direct-current motor concerning a proportionality. It is the histogram which compared the linkage flux of the direct-current motor which concerns on 1st Embodiment, and the linkage flux of the direct-current motor which concerns in contrast. It is a histogram which shows the inductance of the coil of the direct-current motor shown by FIG.2, FIG4 and FIG.7. It is a plane sectional view corresponding to Drawing 2 showing the direct-current motor concerning a 2nd embodiment. It is a plane sectional view corresponding to Drawing 2 showing the direct-current motor concerning a 3rd embodiment. It is a plane sectional view corresponding to Drawing 2 showing the direct-current motor concerning a 4th embodiment. It is a plane sectional view corresponding to Drawing 2 showing the direct-current motor concerning a 5th embodiment. It is a schematic diagram which shows an example of the connection relationship between each coil of the direct-current motor which concerns on 3rd Embodiment, and each segment of a commutator. It is a schematic diagram which shows an example of the connection relationship between each coil of the direct-current motor which concerns on 3rd Embodiment, and each segment of a commutator.

  A DC motor according to a first embodiment of the present invention will be described with reference to FIGS. In addition, the arrow Z direction, the arrow R direction, and the arrow C direction that are appropriately shown in the drawing respectively indicate the axial direction, the radial direction, and the circumferential direction of the DC motor. In the following description, when only the axial direction, radial direction, and circumferential direction are indicated, the axial direction, radial direction, and circumferential direction of the DC motor are indicated unless otherwise specified.

  As shown in FIG. 1, the DC motor 10 of the present embodiment includes a stator 16 that includes a yoke 12 and a plurality of magnets 14 fixed to the yoke 12, and is rotatable within the stator 16. The rotor 18 is provided, and the brush device 20 that switches energization to the coil 36 that constitutes a part of the rotor 18 by sliding contact with the commutator 34 of the rotor 18 is provided.

  The yoke 12 is formed by subjecting a steel plate material to press working or the like. The yoke 12 includes a cylindrical peripheral wall portion 12A and a bottom that closes one end of the peripheral wall portion 12A. A wall portion 12B and a flange portion 12C extending radially outward from the other end of the peripheral wall portion 12A are provided. As shown in FIG. 2, a plurality of magnets 14 (N-pole magnets 14N and S-pole magnets 14S) are fixed to the radially inner surface of the peripheral wall portion 12A in a state of being arranged at equal intervals along the circumferential direction. Has been. The N pole magnets 14N and the S pole magnets 14S are alternately arranged along the circumferential direction.

  As shown in FIG. 1, a bearing (not shown) on which a rotation shaft 30 of a rotor 18 (described later) is supported is fixed to the bottom wall portion 12 </ b> B of the yoke 12. Further, the cover member 22 is attached to the flange portion 12 </ b> C, whereby the armature (the rotor core 32 and the coil 36) of the rotor 18 is accommodated between the yoke 12 and the cover member 22. It has come to be. A bearing (not shown) that supports the rotary shaft 30 is fixed to the cover member 22.

  The brush device 20 includes a brush (not shown) and a brush holder 24 that holds the brush. The brush holder 24 includes a plate member 26 formed in a disk shape and a pair of brush guide portions 28 fixed to the plate member 26. Then, a brush (not shown) is inserted into the brush guide portion 28, and the brush inserted into the brush guide portion 28 is urged radially inward by a spring (not shown), so that the brush and the commutator 34 slide. It comes to touch. In the present embodiment, one brush guide portion 28 and the other brush guide portion 28 are arranged at an interval of 180 ° along the circumferential direction.

  Next, the structure of the rotor 18 which is the principal part of this embodiment is demonstrated.

  As shown in FIGS. 1 and 2, the rotor 18 includes a rotation shaft 30, a rotor core 32 and a commutator 34 fixed to the rotation shaft 30, and main pole portions 40 of the rotor core 32. And a plurality of coils 36 provided around.

  As shown in FIG. 1, the rotating shaft 30 is formed in a rod shape using a steel material or the like. One end portion of the rotating shaft 30 is pivotally supported by a bearing fixed to the bottom wall portion 12B of the yoke 12, and the other end side of the rotating shaft 30 is inserted into the cover member 22 and covers the cover member 22. It is supported by a bearing fixed to

  As shown in FIG. 2, the rotor core 32 includes an iron core annular portion 38 formed in a thick cylindrical shape, and a plurality of main poles extending radially outward from the radially outer surface of the iron core annular portion 38. Part 40 and a plurality of complementary pole parts 42.

  A press-fit hole 38A into which the rotary shaft 30 is press-fitted is formed in the shaft center portion of the iron core annular portion 38, and the rotor core 32 is rotated into the rotary shaft 30 by press-fitting the rotary shaft 30 into the press-fit hole 38A. It is supposed to be fixed to.

  The main pole portion 40 extends radially outward from the radially outer surface of the core annular portion 38 and has a winding portion 40A around which a later-described winding 44 is wound, and a radially outer portion of the winding portion 40A. And an opposing portion 40B extending from the end portion toward the one side and the other side in the circumferential direction. Further, the radially outer surface S1 of the facing portion 40B is formed in an arc shape when viewed in the axial direction. Moreover, in this embodiment, the six main pole parts 40 are arrange | positioned at equal intervals along the circumferential direction.

  The auxiliary pole portion 42 is directed radially outward from the radially outer surface of the core annular portion 38 between the one main pole portion 40 and another main pole portion 40 adjacent to the one main pole portion 40. A general portion 42A that extends, and a facing portion 42B that extends from the radially outer end of the general portion 42A toward one side and the other side in the circumferential direction, respectively. The width B1 (dimension in the circumferential direction) of the general part 42A is set narrower than the width B2 of the winding part 40A of the main pole part 40, and the width B3 (dimension in the circumferential direction) of the facing part 42B is The width is set narrower than the width B4 of the facing portion 40B of the main pole portion 40. Further, the radially outer surface S2 of the facing portion 42B is formed in an arc shape having substantially the same radius as the radially outer surface S1 of the facing portion 40B of the main pole portion 40 as viewed in the axial direction. Further, the thickness T of the end portion in the circumferential direction of the facing portion 42B and the thickness T of the end portion in the circumferential direction of the facing portion 40B of the main pole portion 40 are substantially the same thickness. Moreover, in this embodiment, the six supplemental pole parts 42 are arrange | positioned at equal intervals along the circumferential direction.

  As shown in FIGS. 1 and 3, the commutator 34 includes a plurality of segments 34 </ b> A with which a brush (not shown) is slidably contacted. In the present embodiment, twelve segments 34 </ b> A are arranged at equal intervals along the circumferential direction. Has been.

  As shown in FIG. 2, in this embodiment, two windings 44 are wound around the winding part 40 </ b> A of one main pole part 40, thereby winding one main pole part 40. Two coils 36 are formed around the portion 40A.

  As shown in FIG. 3, the terminal portion of one coil 36 provided around the winding portion 40A of the first main pole portion 40 is connected to the first segment 34A and the twelfth segment 34A. The terminal portions of the other coils 36 are connected to the tenth segment 34A and the eleventh segment 34A. The terminal portion of one coil 36 provided around the winding portion 40A of the second main pole portion 40 is connected to the second segment 34A and the third segment 34A, and the other coil 36 ends. The section is connected to the first segment 34A and the twelfth segment 34A. The terminal portion of one coil 36 provided around the winding portion 40A of the third main pole portion 40 is connected to the fourth segment 34A and the fifth segment 34A, and the other coil 36 ends. Are connected to the second segment 34A and the third segment 34A. The terminal portion of one coil 36 provided around the winding portion 40A of the fourth main pole portion 40 is connected to the sixth segment 34A and the seventh segment 34A, and the other coil 36 ends. Are connected to the fourth segment 34A and the fifth segment 34A. The terminal portion of one coil 36 provided around the winding portion 40A of the fifth main pole portion 40 is connected to the eighth segment 34A and the ninth segment 34A, and the other coil 36 ends. The section is connected to the sixth segment 34A and the seventh segment 34A. The terminal portion of one coil 36 provided around the winding portion 40A of the sixth main pole portion 40 is connected to the 10th segment 34A and the 11th segment 34A, and the other coil 36 ends. Are connected to the eighth segment 34A and the ninth segment 34A.

(Operation and effect of this embodiment)
Next, the operation and effect of this embodiment will be described.

  As shown in FIGS. 1 to 3, according to the DC motor 10 of the present embodiment, energization to the 12 coils 36 is switched by a brush (not shown) slidingly contacting each segment 34 </ b> A of the commutator 34. . As a result, the magnetic field generated in the rotor core 32 is switched, and the rotor 18 rotates relative to the stator 16 by the magnetic field and the magnetic field of the magnet 14 of the stator 16.

  In the present embodiment, since the auxiliary pole portion 42 is provided between the main pole portions 40, the cogging torque and the torque ripple of the DC motor 10 can be reduced.

  Further, in the DC motor 10, a plurality of coils 36 are provided around each main pole portion 40. In other words, two coils 36 are provided around one main pole portion 40. As a result, a decrease in winding coefficient is suppressed as compared with the DC motor 46 in which one coil 36 is provided around one pole portion 50 shown in FIG. It can suppress that magnetic flux decreases.

  Here, the direct current motor 46 related to the proportionality will be described. The rotor core 48 of the direct current motor 46 includes twelve pole portions 50. One coil 36 is formed around one pole portion 50. Note that the number of turns of one coil 36 formed around one pole portion 50 is the same as the number of turns of the coil 36 of the above embodiment. As shown in FIG. 5, when the interlinkage magnetic flux of the coil 36 of the DC motor 46 and the interlinkage magnetic flux of the coil 36 of the DC motor 10 of the present embodiment are compared, in this embodiment, the decrease of the interlinkage magnetic flux is suppressed. You can see that

  Further, by adopting a configuration in which two coils 36 are provided around one main pole portion 40, compared to a case where a single coil having the same number of turns is provided around the main pole portion 40, It can be suppressed that the number of turns of one coil 36 is reduced and the inductance of the coil 36 is increased. As shown in FIG. 6, when the inductance of the coil 36 of the DC motor 46 is compared with the inductance of the coil 36 of the DC motor 10 of this embodiment, it can be seen that the inductance is reduced in this embodiment. Further, as shown in FIG. 6, a configuration in which four coils 36 are provided around one main pole portion 40 as in the DC motor 52 according to the second embodiment shown in FIG. 7. Thus, the inductance of the coil 36 can be further reduced.

  In addition to this, as shown in FIG. 3, in the DC motor 10 of the present embodiment, two coils 36 provided around one main pole portion 40 are connected to a pair of different segments 34A, respectively. Yes. Thereby, the energy at the time of switching the energization to the coil 36 due to the brush being in sliding contact with each segment 34A can be reduced, and consequently the life of the brush can be prevented from being reduced. In addition, noise during switching of energization to the coil 36 can be reduced.

(DC motor according to another embodiment)
Next, a DC motor according to another embodiment of the present invention will be described. In addition, about the member and part which have the same function as the said embodiment, the code | symbol same as the said embodiment is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 8, the DC motor 54 according to the third embodiment includes a stator 16 including four magnets 14, three main pole portions 40, and three auxiliary pole portions 42. It is configured to include.

  As shown in FIG. 9, the DC motor 56 according to the fourth embodiment includes a stator 16 including six magnets 14, five main pole portions 40, and five auxiliary pole portions 42. , Including.

  Further, as shown in FIG. 10, the DC motor 58 according to the fifth embodiment includes a stator 16 including ten magnets 14, eight main pole portions 40, and eight auxiliary pole portions 42. And.

  A plurality of coils 36 are provided in each of the main pole portions 40 of the DC motors 54, 56, and 58 shown in FIGS.

  The DC motors 54, 56, and 58 shown in FIGS. 8 to 10 include the commutator 34 having the number of segments 34 </ b> A corresponding to the total number of coils 36. As an example, a DC motor 54 according to the third embodiment in which two coils 36 are provided around one main pole portion 40 includes a commutator 34 having six segments 34A as shown in FIG. ing. The terminal portion of one coil 36 provided around the winding portion 40A of the first main pole portion 40 is connected to the first segment 34A and the sixth segment 34A, and the other coils 36 are connected. Are connected to the third segment 34A and the fourth segment 34A. The terminal portion of one coil 36 provided around the winding portion 40A of the second main pole portion 40 is connected to the second segment 34A and the third segment 34A, and the other coil 36 ends. Are connected to the fifth segment 34A and the sixth segment 34A. The terminal portion of one coil 36 provided around the winding portion 40A of the third main pole portion 40 is connected to the fourth segment 34A and the fifth segment 34A, and the other coil 36 ends. The section is connected to the first segment 34A and the second segment 34A.

  A DC motor 54 according to the third embodiment in which four coils 36 are provided around one main pole portion 40 includes a commutator 34 having twelve segments 34A as shown in FIG. ing. And the terminal part of the 1st coil 36 provided around the winding part 40A of the 1st main pole part 40 is connected to the 1st segment 34A and the 12th segment 34A, and the 2nd The terminal portion of the coil 36 is connected to the sixth segment 34A and the seventh segment 34A, and the terminal portion of the third coil 36 is connected to the third segment 34A and the fourth segment 34A. The terminal portion of the fourth coil 36 is connected to the ninth segment 34A and the tenth segment 34A. The terminal portion of the first coil 36 provided around the winding portion 40A of the second main pole portion 40 is connected to the fourth segment 34A and the fifth segment 34A, and the second The terminal part of the coil 36 is connected to the 10th segment 34A and the 11th segment 34A, and the terminal part of the third coil 36 is connected to the 7th segment 34A and the 8th segment 34A. The terminal portion of the fourth coil 36 is connected to the first segment 34A and the second segment 34A. Further, the terminal portion of the first coil 36 provided around the winding portion 40A of the third main pole portion 40 is connected to the eighth segment 34A and the ninth segment 34A, and the second The terminal part of the coil 36 is connected to the second segment 34A and the third segment 34A, and the terminal part of the third coil 36 is connected to the eleventh segment 34A and the twelfth segment 34A. The terminal portion of the fourth coil 36 is connected to the fifth segment 34A and the sixth segment 34A.

  In the DC motors 54, 56, 58 described above, the number of main pole portions is T, and the number of pole pairs of the magnets 14 constituting a part of the stator (the number of pairs of N pole magnets 14N and S pole magnets 14S). Is set to P, and the number of the segments 34A is set to a number obtained by T × P × n (n = 1, 2, 3,...), Whereby the DC motor 10 according to the first embodiment and the second embodiment is set. , 52, it is possible to suppress an increase in inductance of the coil 36 while suppressing a decrease in interlinkage magnetic flux of the coil 36.

  In addition, although the said embodiment demonstrated the case where the number of the main pole parts 40 was 3, 5, 6 and 8, this invention is not limited to this. The number of main pole portions 40 may be set as appropriate in consideration of output characteristics of the DC motor, torque fluctuation, and the like.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and various modifications other than the above can be implemented without departing from the spirit of the present invention. Of course.

DESCRIPTION OF SYMBOLS 10 ... DC motor, 14 ... Magnet, 16 ... Stator, 18 ... Rotor, 30 ... Rotating shaft, 32 ... Rotor core, 34 ... Commutator, 34A ... Segment, 36 ... Coil, 40 ... Main pole part, 42 ... complement electrode part, 44 ... winding, 52 ... DC motor, 54 ... DC motor, 56 ... DC motor, 58 ... DC motor

Claims (2)

A stator having a magnet;
A plurality of main pole portions fixed to a rotary shaft provided radially inside the stator and extending in the radial direction and spaced apart along the circumferential direction, and extending in the radial direction and each of the main pole portions A rotor core having a plurality of auxiliary pole portions disposed between the pole portions, a commutator having a plurality of segments fixed to the rotating shaft and in sliding contact with the brush, and a pair of the terminal portions different from each other A rotor having a plurality of coils formed around each of the main pole portions formed by winding a plurality of windings connected to a segment, and
DC motor equipped with. The number of the main pole portions is T, the number of pole pairs of the magnets constituting a part of the stator is P,
The DC motor according to claim 1, wherein the number of segments is set to a number obtained by T × P × n (n = 1, 2, 3,...).

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