JPH02142350A - Motor provided with polyphase dc core - Google Patents

Abstract

PURPOSE:To reduce cogging torque by confining simultaneous occurrence of cogging torque only to two points on a diagonal line. CONSTITUTION:If P=2(nPHI+ or -1), N=2nPHI, (n is an integer equal to or larger than 2), where P is the number of pole, N is the number of slot and PHI is the number of phase, simultaneous occurrence of cogging torque is confined to two pints on a diagonal line. If PHI=2 and n=3, the number of pole is 14 and the number of slot is 12. Since the salient poles C1-C12 of a core C-1 corresponding to a magnetic pole M-1 have phase shift, coil is wound around three adjoining salient poles having small phase shift while inverting the winding direction, then the coil is wound around three other salient poles located axis symmetrically to the aforementioned salient poles while inverting the winding direction thereafter total six coils are connected in series to provide a coil for one phase.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a polyphase DC motor, and particularly to a polyphase DC core motor that significantly reduces cogging and reduces vibration and noise.

(Prior Art) In recent years, multiphase DC motors having a core in the armature have been widely used.

In this multiphase DC core motor, cogging occurs between the slot of the core and the boundary between the field magnetic poles (the boundary between the N pole and the S pole). Principle of cogging in conventional motors (
The mechanism) will be explained below using a three-phase motor as an example.

In a conventional three-phase DC motor, the combination of the number of field magnetic poles P and the number of slots (number of salient poles) N is generally P-(3±l
)n, N=3n (where n is a natural number).

As shown in Tables 1 and 2, the cogging in this conventional three-phase DC motor is expressed by the number of cogging occurrences per rotor rotation being the least common multiple of P and N, and the locations where cogging occurs at the same time. The number is expressed as the greatest common divisor of P and N.

(Left below) Regarding the principle of cogging in conventional motors, for case n-4 (8 poles, 12 slots) in Table 2,
This will be explained with reference to FIGS. 7 to 9.

FIG. 7 is a ring top sectional view showing an example of a conventional three-phase DC motor, FIG. 8 is a plan development view of the motor in FIG. 7, and FIG. 9 is a cross-sectional view of the motor in FIGS. 7 and 8. FIG. 3 is a waveform diagram for explaining the principle of cogging generation.

As shown in Figure 7, three conventional examples of 8 poles and 12 slots
The phase-dc motor 5 has an armature part in which a coil L-5 is wound around each slot between salient poles C-C12 of a core C-5, and a magnetic pole M which is radially magnetized into eight poles on the inner circumference. -5 is formed on the outer periphery of the cylindrical magnet (in the figure, the inner magnetic pole M-5 is written on the upper end surface),
A field part, in which the inner periphery of an iron cylindrical yoke Y for forming a magnetic path is fixed, is arranged with a certain air gap t interposed therebetween.

In this three-phase DC motor 5, when one of the armature section or the field section is fixed and the other is rotated, the magnetic pole M-
Cogging occurs between the boundary a % h of the N and S poles of 5 and this slot, and at each boundary a - h, the 9th
Cogging waveforms as shown in FIGS. (a) to (h) occur. The cogging of the entire motor 5 is a combination of these, resulting in a waveform as shown in Figure (i), which is expressed as the least common multiple of the number of magnetic poles (P-8) and the number of slots (N-12). 24 coggings occur per revolution. Also, the number of places where this cogging occurs at the same time is
Since there are four locations represented by the greatest common divisor of the number of magnetic poles and the number of slots, the magnitude of one cogging for the motor 5 as a whole is approximately 4 It will be doubled.

Moreover, the coil winding method of this motor 5 is as shown in FIG.

is in the same phase as the magnetic pole M-5, so if the coil L-5 is wound in the CW (clockwise) direction around the salient pole C1, the salient pole C4°C7''10 is similarly wound in the CW force direction to form a U-phase coil.The same applies to V-phase coils and W-phase coils.In the figure, the suffix S for each phase indicates the beginning of winding. ,
e represents the end of the volume.

Moreover, the phase difference φ between the adjacent salient poles with respect to the magnetic pole M-5 is expressed in electrical angle as φ-(360'/N)X (P/2)...(1
), and in the case of the motor 5, between adjacent salient poles around which the U-phase and V-phase coils are wound, for example, the salient pole C1
The phase difference between C2 and C2 is 120 degrees in electrical angle. Similarly, the phase difference between adjacent salient poles around which the V-phase and W-phase coils are wound, and between adjacent salient poles around which this W-phase coil is wound, is also 120 degrees in electrical angle. It has become.

The U-phase, ■-phase, and W-phase coils each have a phase difference of 120' in electrical angle.

By flowing three-phase driving currents of phase (1) and phase W, a continuous rotational torque is generated between the armature section and the field section, thereby forming a three-phase DC motor 5. In this case, as mentioned above, since the four salient poles are in the same phase with respect to the magnetic pole M-5, the magnitude of one cogging of the motor 5 as a whole is equal to the cogging torque generated in one slot. Approximately 4 times more.

(Problems to be Solved by the Invention) In the conventional three-phase DC motor 5 having the above configuration, as described above, the magnitude of one cogging of the motor 5 as a whole is equal to the cogging that occurs in one slot. The torque is multiplied by the number of locations where cogging occurs simultaneously, and since the number of locations where cogging occurs simultaneously is large, there is a problem in that the cogging is large.

Furthermore, as shown in Tables 1 and 2 above, as the n increases, the number of places where cogging occurs at the same time also increases, so in order to reduce torque ripple, etc., the number of magnetic poles P
When the number of slots (the number of salient poles) N is increased, there is a problem that this cogging also increases.

When the motor 5 is used, for example, as a drum motor or capstan motor of a VTR, this cogging adversely affects jitter and wow and flutter, and causes noise and vibration.

In addition, in order to reduce this cogging, there are methods such as manipulating the magnetization waveform or providing an auxiliary groove or a commutating pole in the core C-5, but the method of manipulating the magnetization waveform requires setting conditions. This is difficult, and the method of providing auxiliary grooves reduces the total amount of magnetic flux, resulting in a decrease in generated torque. In addition, the interpolation reduces the winding space and the generated torque, especially when the motor is downsized.

The present invention has been made with attention to the above points, and the cogging is small overall, and even if the number of magnetic poles and the number of slots are increased, the cogging does not increase, and the output and efficiency do not decrease, and the manufacturing The object of the present invention is to provide a motor with a multiphase DC core that does not increase cost.

(Means for Solving the Problems) The polyphase DC core motor of the present invention has N, S
A field part having P-pole field magnetic poles with alternating poles, and N
and an armature part having a core having a Φ-phase winding in N winding slots between the salient poles, and one of the field part and the armature part is connected to the other. In a rotatable multi-phase DC core motor, the number of field magnetic poles P
The combination of and the number of armature core slots (number of salient poles) N is P
-2(nΦ±1) N-2nΦ (where n is an integer of 2 or more), and the winding is wound around the n adjacent salient poles while reversing the winding direction. , and then winding the salient poles while reversing the winding direction so that the phase matches n salient poles located axially symmetrically with these salient poles, winding them around a total of 20 salient poles and connecting them in series to form one phase. It is configured to be a winding wire.

Further, in the multiphase DC core motor of the present invention, when the number of phases is Φ' (however, Φ' is an even number of 4 or more), the field magnetic pole number P and the electric motor The combination with the number of child core slots (number of salient poles) N is obtained from the above formula as Φ = Φ'/2, and the winding is
The winding wire is configured to be wound around n adjacent salient poles while reversing the winding direction to form one phase winding wire.

(Example) In order to reduce the cogging, the multiphase DC core motor of the present invention provides a method for selecting the number P of magnetic poles and the number N of slots (
This is a system in which the number of locations where cogging occurs simultaneously is always two on the diagonal, regardless of the number of magnetic poles P and the number of slots N. It is. Examples of the present invention in which the number of phases is 2 to 5 will be described below.

First, a first embodiment of the present invention in which the number of phases is two will be described.

In the two-phase DC motor of the first embodiment of the present invention, the combination of the number of magnetic poles P and the number of slots (number of salient poles) N is P=
2 (2n±1), N-4n (where n is an integer of 2 or more). As shown in Tables 3 and 4, the cogging in the two-phase DC motor of the first embodiment depends on the number of locations where cogging occurs at the same time as the number of magnetic poles P and the number of slots N. There is no difference, and the two locations are always on the diagonal.

(Left below) A specific configuration example of the two-phase DC motor according to the first embodiment of the present invention is shown in the case of n-3 in Table 3 (14 poles, 12 poles).
The slot) will be explained in Fig. 1.

FIG. 1 is a developed plan view showing an example of a two-phase DC motor which is a first embodiment of the multi-phase DC core motor of the present invention.

In this figure, parts similar to those of the conventional example shown in FIGS. 7 and 8 are given the same reference numerals, and detailed explanation thereof will be omitted.

As shown in the figure, the first embodiment of the present invention has 14 poles and 12 slots.
In the coil winding method in the two-phase DC motor of the embodiment, since the salient pole C-C12 of the core C-1 is out of phase with respect to the magnetic pole M-1, adjacent n-3 The coil is wound around the salient poles while reversing the winding direction, and then the coil is wound while reversing the winding direction so that the phase matches the three salient poles that are axially symmetrical to these salient poles. , are wound around a total of six salient poles and connected in series to form one phase coil.

That is, the coil L-1 is connected to the salient pole C2, for example, in a CCW manner.
Assuming that the winding is in the (counterclockwise) direction, the phase difference φ1 between the salient poles C and C with respect to the magnetic pole M-2 for the salient pole C1 is expressed in electrical angle from the first equation, φ1- (360”/12)X7-210°,
If it is wound in the CW force direction, the phase difference φ1' of the back electromotive force waveform becomes φ,'-210''-180''-30'.

At the same time, the phase difference between the salient pole C and this salient pole C1 is 210
Therefore, if it is wound in the CCW direction, the phase difference of the back electromotive force waveform will be 30''.Furthermore, the salient pole C is
Since the phase is 180' out of phase with respect to ゜, it is sufficient to wind it in the CW force direction, and since the salient pole C is out of phase with this salient pole C1 by 180', it is sufficient to wind it in the CCW direction. Also, since the salient pole C is out of phase by 180@ with respect to the salient pole C2, it is sufficient to wind it in the CW force direction. in this way,
C (CCW) → C1 (CW) → C2 (CCW) → C (C
W) → C7 (CCW) → C8 (CW), 6
The A-phase (first phase) coil is configured by continuously winding the coil around two salient poles.

Also, the phase difference φ2 of the salient pole C with respect to the salient pole C1□ is given by the electrical angle from the first equation, φ2- (360' /12)X7X3 (th) 雡6
30@-360' +270°, that is, 270"(-180'+90'), and by starting the winding direction from the CW force direction, the salient poles C and C12 have a 90° phase difference, so as mentioned above, As in the case of the A-phase coil, C3(CW)C(CCW)→C
5 (CW) → C9 (CCW) → C1o (CW) → C11
(CCW), a B-phase (second phase) coil is constructed by continuously winding the coil around six salient poles.

The A-phase and B-phase coils have a phase difference of 90'' in electrical angle, respectively, in the human-phase forward direction, B-phase forward direction, and A-phase forward direction.
By passing driving current in both directions, that is, in the opposite direction of the phase and in the direction of the B phase, a continuous rotational torque is generated between the armature section and the field section, thereby forming a two-phase DC motor. be done.

In this case, as described above, the two salient poles are connected to the magnetic pole portion M-1.
Since the phase difference is 180@, the magnitude of one cogging for this motor as a whole is approximately twice the cogging torque generated in one slot.

FIG. 5 is a back electromotive force waveform diagram for explaining the operation of the motor shown in FIG. 1, in which (A) is a back electromotive force waveform diagram of the A phase, and (B) is a back electromotive force waveform diagram of the B phase.

In the figure (A), the curve a1 is the salient pole C1□.

Back electromotive force waveform generated in the coil wound around C6, curve a
is the coil 2 1 wound around the salient poles C and C.
The fully generated back electromotive force waveform, curve a3, corresponds to the salient poles C2 and C.
The back electromotive force waveform generated in the coil wound in phase 8, curve a, is a composite waveform of this curve a + 82 + 83, that is, the back electromotive force waveform of the A-phase coil. Similarly, in the same figure (B), curve b is for the coil wound around the salient pole C3°C, curve b2 is for the coil wound around the salient poles C4 and C, and curve b3 is for the coil wound around the salient pole C3°C. The waveform of the back electromotive force generated in the coil coil wound around the poles C and C is a composite waveform of the curves b, b, and bl23, that is, the waveform of the back electromotive force of the B-phase coil. As shown in the figure, the back electromotive force waveforms of the A-phase and B-phase coils have a phase difference of 90'', and therefore can be continuously rotated by the aforementioned two-phase bidirectional drive current.

Next, a second embodiment of the present invention in which the number of phases is three will be described.

In the three-phase DC motor according to the second embodiment of the present invention, the combination of the number of magnetic poles P and the number of slots (number of salient poles) N is P-
2 (3n±l), N-6n (however, n is an integer greater than or equal to 2)
Configure it so that As shown in Tables 5 and 6, the cogging in the three-phase DC motor of the second embodiment is such that the number of locations where cogging occurs simultaneously is as follows:
Regardless of the number of magnetic poles P and the number of slots N, there will always be two locations on the diagonal.

(Left below) A specific configuration example of the three-phase DC motor according to the second embodiment of the present invention is shown in the case of n-2 in Table 5 (14 poles, 12 poles).
slot) will be explained in Figure 2.

FIG. 2 is a developed plan view showing an example of a three-phase DC motor which is a second embodiment of the multi-phase DC core motor of the present invention.

In this figure, parts similar to those of the conventional example shown in FIGS. 7 and 8 are given the same reference numerals, and detailed explanation thereof will be omitted. Also, 14 poles.

Since this is an example of 12 slots, it is the same as the case of the first embodiment described above, and the magnetic pole M-2 and core C-2 in this embodiment are the same as the magnetic pole M-1 and core C-2 in the first embodiment.
-1 is the same.

As shown in the figure, the second embodiment of the present invention has 14 poles and 12 slots.
The coil winding method in the three-phase DC motor 2 of the embodiment is as follows:
Since the phases of the two salient poles are shifted, ■ the coil is wound around n-2 adjacent salient poles with a small phase shift while reversing the winding direction, and then the two salient poles that are axially symmetrical to these poles are wound. This coil is wound while reversing the winding direction so that the phase matches each salient pole, and the windings are wound around four salient poles in total and connected in series to form one phase coil.

That is, if the coil L-2 is wound around the salient pole C1 in the CW force direction, the coil L-2 is wound around the salient pole C1 in the CW force direction.
-2, the phase difference φ3 between the salient poles C and C2 is the first
From the formula, in electrical angle, φ3- (360” /12)X7-
210°, and if it is wound in the CCW direction, the phase difference φ' of the back electromotive force waveform will be φ3'-210'-180@-30°.

Furthermore, the salient pole C7 has a phase of 180" with respect to this salient pole C1.
Since they are shifted, it is sufficient to wind them in the CCW direction, and since the salient pole C is out of phase by 180@ with respect to this salient pole C2, it is sufficient to wind them in the CW force direction. , thus, C(CW
)→C2(CCW)→C7(CCW)→C8(CW), the U-phase (first phase) coil is constructed by continuously winding the coil around the four salient poles.

Also, the phase difference φ4 of the salient pole C5 with respect to the salient pole C1 is expressed in electrical angle from the first equation as φ4- (360'/12)X7X4 (th)-8
40＠-2X360'
) → C6 (CCW) → C (CCW) → Cl2 (CW), by continuously winding around the four salient poles, a ■phase (second phase) coil is constructed. Furthermore, starting with C9, which is out of phase by 240@ with respect to this salient pole C, C9 (CW) → C1o (CCW) → C3 (CCW
)→C4 (CW), a W-phase (third phase) coil is constructed by continuously winding the coil around four salient poles.

The U-phase, ■-phase, and W-phase coils each have a phase difference of 120 degrees in electrical angle.

By flowing three-phase driving currents of phase (1) and phase W, continuous rotational torque is generated between the armature section and the field section, thereby forming a three-phase DC motor 2. In this case, as described above (, the two salient poles are 180° with respect to the magnetic pole M-2).
Since this is a phase difference, the magnitude of one cogging of the motor 2 as a whole is approximately twice the cogging torque generated in one slot.

Figure 6 is a back electromotive force waveform diagram for explaining the operation of the motor in Figure 2, where (A) is for the U phase, (B) is for the V phase, and (C) is for the W phase. It is a back electromotive force waveform diagram.

In the same figure (A), the curve u1 is the waveform of the back electromotive force generated in the coil wound around the salient poles C1 and C7, and the curve U is the waveform of the back electromotive force generated in the coil wound around the salient poles C and C. The waveform, curve U, is a composite waveform of these curves u1 and u2, that is, the back electromotive force waveform of the U-phase coil. Similarly, the curve v in the same figure (B)
1 has a curve V in the coil wound around the salient poles C and C1□.
occurs in the coil wound around the salient pole C-C12.

The back electromotive force waveform, curve V, is a composite waveform of these curves V1 and v2, that is, the back electromotive force waveform of the V-phase coil. Similarly, the same figure (
In C), the curve w1 is the waveform of the back electromotive force generated in the coil wound around the salient poles C and C9, the curve W is the back electromotive force waveform generated in the coil wound around the salient poles C and C, and the curve W is the waveform of the back electromotive force generated in the coil wound around the salient poles C and C. and W2, that is, the back electromotive force waveform of the W-phase coil.

As shown in the figure, the back electromotive force waveforms of the U-phase, ■-phase, and W-phase coils each have a phase difference of 120', and therefore can be continuously rotated by the aforementioned three-phase drive current.

When the various characteristics of this 3-phase DC motor 2 were measured in comparison with a conventional 3-phase DC motor with 16 poles and 12 slots, which is most similar in configuration to this motor, the cogging torque and torque constant were as follows. The example motors each have 5
．． 7 [g-(to)], 0. lL2 [g-cm/iA]
In contrast, the motor 2 of the second embodiment of the present invention
are 0.26[g-cm] and 0.117[g-cm], respectively.
-cm/m^], and it was confirmed that the generated torque was improved by about 4%, and the cogging torque was significantly reduced (1/20 or less).

Next, a third embodiment of the present invention in which the number of phases is four will be described.

In the 4-phase DC motor of the third embodiment of the present invention, the combination of the number of magnetic poles P and the number of slots (number of salient poles) N is set to P-
2 (4n±1), N-8n (however, n is an integer greater than or equal to 2)
It is also possible to configure the motor so that it is configured so that it rotates continuously using a four-phase bidirectional drive current as in the case of the first embodiment described above, but here, the value of the number of phases 4 was calculated as 1/2. , an example will be described in which a 4-phase coil is wound around the same combination of the number of magnetic poles P and the number of slots (number of salient poles) N as in the first embodiment, and is continuously rotated by a 4-phase unidirectional drive current. do. The combination of the number of magnetic poles P and the number of slots (number of salient poles) N in this third embodiment is the same as that in the first embodiment, as described above, and therefore the explanation thereof will be omitted.

A specific example of the configuration of the 4-phase DC motor according to the third embodiment of the present invention will be described with reference to FIG. 3 for the case n-3 (14 poles, 12 slots) in Table 3 mentioned above.

FIG. 3 is a developed plan view showing an example of a four-phase DC motor which is a third embodiment of the multi-phase DC core motor of the present invention.

In this figure, parts similar to those of the conventional example shown in FIGS. 7 and 8 are given the same reference numerals, and detailed explanation thereof will be omitted. Moreover, as mentioned above, since the magnetic pole and core are the same as those in the first embodiment, the magnetic pole M-
3 and core C-3 are the magnetic pole M-1 in the first embodiment.
and core C-1.

As shown in the figure, the third embodiment of the present invention has 14 poles and 12 slots.
The coil winding method in the four-phase DC motor 3 of the embodiment is as follows:
Since the phase of C12 is shifted, the coil is wound around three adjacent nwm salient poles with a small phase shift while reversing the winding direction to form a single phase coil.

That is, if the coil L-3 is wound in the CCW direction around the salient pole C12, for example, it is wound in the CW force direction around the salient pole C1, and further in the CCW direction around the salient pole C2. All you have to do is wind it. In this way, Cl2(CCW)→C1(C
The A-phase (first phase) coil is constructed by continuously winding the coil around the three salient poles so that W)→C2(cCw).

Moreover, the phase difference of the salient pole C3 is shifted by 270'(-180'+90") in electrical angle from this salient pole C1□, and by starting the spring direction from the CW force direction, this salient pole Since C3 and C1° have a 90" phase difference, as in the case of the A-phase coil described above, C3 (CW) → C (CCW) - C
The B-phase (second phase) coil is constructed by continuously winding the coil around the three salient poles so that the coil is 5CCW'').

Similarly, C (CCW) → C7 (CW) → C8 (CCW)
By continuously winding around three salient poles, a C phase (third phase) coil is constructed, and C (CW)→C1
A D-phase (fourth phase) coil is constructed by continuously winding the coil around the three salient poles so that o(CCW)→C11(CW).

Then, each coil of A phase, B phase, C phase 2 D phase,
By passing unidirectional four-phase drive currents each having a phase difference of 90'' in electrical angle, a continuous rotational torque is generated between the armature section and the field section, resulting in a four-phase DC current. A motor 3 is configured.

In this case, as described above, the two salient poles are connected to the magnetic pole part M-3.
Since there is a phase difference of 180a with respect to the motor 3, the magnitude of one cogging of the motor 3 as a whole is approximately twice the cogging torque generated in one slot.

Next, a fourth embodiment of the present invention in which the number of phases is five will be described.

In the 5-phase DC motor of the fourth embodiment of the present invention, the combination of the number of magnetic poles P and the number of slots (number of salient poles) N is P=
2 (5n±1), N-1On (where n is an integer of 2 or more).

As shown in Tables 7 and 8, the cogging in the 5-phase DC motor of the fourth embodiment depends on the number of locations where cogging occurs at the same time as the number of magnetic poles P and the number of slots N. Regardless, there will always be two locations on the diagonal.

(Left below) A specific configuration example of the 5-phase DC motor according to the fourth embodiment of the present invention is shown in the case of n-2 in Table 8 (18 poles, 20
slot) will be explained in Figure 4.

FIG. 4 is a developed plan view showing an example of a five-phase DC motor which is a fourth embodiment of the multi-phase DC core motor of the present invention.

In this figure, parts similar to those of the conventional example shown in FIGS. 7 and 8 are given the same reference numerals, and detailed explanation thereof will be omitted.

As shown in the figure, the fourth embodiment of the present invention has 18 poles and 20 slots.
The coil winding method in the five-phase DC motor 4 according to the embodiment is as follows:
Since the phase of the coil is out of phase with each other, the coil is wound around n-2 adjacent salient poles with a small phase shift while reversing the winding direction, and the coil is wound in a position axially symmetrical with these salient poles. The coil is wound while reversing the winding direction so that the phase matches the two salient poles, and a total of four salient poles are wound and connected in series to form one phase coil.

That is, if the coil L-4 is wound around the salient pole C1 in the CW force direction, the coil L-4 is wound around the salient pole C1 in the CW force direction.
The phase difference φ5 between this salient pole C1C with respect to
62', and if it is wound in the CCW direction, the phase difference φ of the back electromotive force waveform becomes φ5'-180'-162' -18@.

Furthermore, since the salient pole C has a phase shift of 180° with respect to the salient pole C1, it is sufficient to wind it in the CCW direction.
Since the phase is shifted by 180' with respect to this salient pole C2, it is sufficient to wind it in the CW force direction. In this way, C(CW)→
The A-phase (first phase) coil is constructed by continuously winding the coil around the four salient poles so that C2(CCW)→C(CCW)→Cl2(CW).

Also, the phase difference φ6 of the salient pole C7 with respect to the salient pole C1 is expressed in electrical angle from the first equation as φ6- (360°/20)x9x6 (th)-97
2°-2X360'+252", i.e. 252' (
-180"+72°), and as in the case of the A-phase coil described above, C7 (CCW) → C8 (CW) → C17
(CW) → Cl8 (CCW), the B-phase (second phase) coil is configured by continuously winding the coil around the four salient poles.

Similarly, C (CCW) → C4 (CW) → C13 (CW)
- C14 (CCW) connects the C phase (3rd phase) coil to C (C
W) → C1o (CCW) → C19 (CCW) - C2o (
CW) to connect the D phase (4th phase) coil, C(CW) → CB
(CCW) → C15 (CCW) → C16 (CW) constitutes an E phase (fifth phase) coil.

By passing five-phase drive currents having a phase difference of 72@ electrical angle through each of the A-phase to E-phase coils, a continuous rotational torque is generated between the armature section and the field section. This generates a five-phase DC motor 4.

In this case, as mentioned above, since the two salient poles have a phase difference of 180° with respect to the magnetic pole M-4, the magnitude of one cogging for the motor 4 as a whole is equal to the cogging generated in one slot. It will be about twice as much.

Motors 1 to 1 of the first to fourth embodiments of the present invention described above
4, the cogging that occurs at the same timing is always at two locations, and the number of locations where the cogging occurs at the same timing is smaller than in the case of the conventional motor 5 mentioned above. cogging becomes smaller. In addition, even if the number of magnetic poles P and the number of slots N are increased, this cogging does not increase, so the degree of freedom in design is increased, and when increasing the number of magnetic poles P and the number of slots N to reduce torque ripple, etc. It will be advantageous.

Note that one cause of cogging deterioration is mechanical eccentricity, but in the case of the present invention, cogging occurs at the same timing at two locations symmetrical with respect to the rotation axis of the motor. Even if the air gap t becomes smaller due to eccentricity and cogging increases,
Since the air gap t at the symmetrical position increases and the cogging decreases, this cogging is averaged out and becomes less susceptible to the influence of this eccentricity.

Furthermore, in general, when the number of cogging occurrences per one rotation is large (cogging frequency is high), this cogging is attenuated and becomes smaller, and when controlling the rotational speed of this motor, due to the servo characteristics, the jitter and Since the wow and flutter can be reduced, the present invention, which generates more cogging per revolution, is more advantageous than the conventional example.

(Effects of the Invention) The multiphase DC core motor of the present invention having the above configuration has the following features:
Cogging torque can be significantly reduced without reducing output or efficiency or increasing manufacturing costs, so when the motor of the present invention is used in devices such as VTRs, jitter, wow and flutter, noise, vibration, etc. can be significantly reduced. As a result, the performance of this device can be improved.

[Brief explanation of the drawing]

1 to 4 are developed plan views showing examples of 2 to 5 phase DC motors which are the first to fourth embodiments of the multiphase DC core motor of the present invention, and FIGS. 5 and 6 are FIGS. 1 and 2 are back electromotive force waveform diagrams for explaining the operation of the motor, FIG. 7 is a schematic top sectional view showing an example of a conventional three-phase DC motor, and FIG.
FIG. 9 is a plan development view of the motor shown in FIG. 9, and a waveform diagram for explaining the principle of cogging generation in the motor shown in FIGS. 7 and 8. 1.2, 3.4...2 to 5 phase, DC motor, C-1
, C-2, C-3, C-4... Core, C-C2o...
・Salient pole, L-1, L-2, L-3, L-4...Coil (winding)
, M-1, M-2, M-3, M-4... field magnetic poles. Patent applicant Kunio Kakaki Komazu (-iL) Representative of Victor Japan Co., Ltd.

Claims (2)

[Claims] (1) A field part has P field magnetic poles with N and S poles arranged alternately at equal angular intervals, and a Φ-phase winding is installed in the N winding slots between the N salient poles. In the motor with a multiphase DC core, in which either the field part or the armature part is rotatable relative to the other, the number of field magnetic poles P and The combination with the number of armature core slots (number of salient poles) N is configured as follows: P = 2 (nΦ ± 1) N = 2nΦ (where n is an integer of 2 or more), and the winding is Winding while reversing the winding direction around the n adjacent salient poles, and further winding while reversing the winding direction so that the phase matches the n salient poles that are axially symmetrical to these salient poles, A multi-phase DC core motor characterized in that the windings are wound around a total of 2n salient poles and connected in series to form one phase winding. (2) When the number of phases is Φ' (however, Φ' is an even number of 4 or more), the combination of the number of field magnetic poles P and the number of armature core slots (number of salient poles) N is Φ=Φ' /2 is obtained from the above formula, and furthermore, the winding is configured so that the winding is wound around the n adjacent salient poles while reversing the winding direction to form a winding of one phase. A polyphase DC core motor according to claim 1.