JP2008263686A - Rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor having high output density by selecting the relation between the total number of magnetic poles of a rotor of a rotary electric machine in which a stator magnetic pole is divided in a circumferential direction and the total number of magnetic poles of a stator thereof in order to solve the problem that a coupled core external circumferential portion of a stator magnetic pole causes magnetic interference in each of phases and a control constant of a controller to be driven is influenced by another phase, resulting in less controllability in a conventional technique. <P>SOLUTION: The rotary electric machine has a stator in which a three-phase stator magnetic pole and a stator winding are provided, the three-phase stator magnetic pole is disposed in a circumferential direction, the stator winding is wound around the stator magnetic pole composed of two columns centered at the circumferential direction for each phase, and the three-phase stator magnetic pole is magnetically divided. In this rotary electric machine, the number of stator magnetic poles is a multiple of 6. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine.

  As a conventional rotating electrical machine in which windings of respective phases are arranged in the circumferential direction, a stator structure in which a coil is wound around a stator magnetic pole as disclosed in JP-T-2005-532775 is disclosed. Further, in the conventional motor, the magnetic poles could not be divided because there was a magnetic flux interlinking the outer periphery of the core back in the circumferential direction.

JP 2005-532775 A

  In the conventional technology, since the core outer peripheral part of the stator magnetic pole is connected, magnetic interference occurs in each phase, and the control constant of the controller to be driven is influenced by other phases, so that the controllability is improved. There are missing issues. Furthermore, it is to provide a motor with high output density by selecting the relationship between the total number of rotor poles and the total number of stator magnetic poles of a rotating electrical machine in which stator magnetic poles are divided in the circumferential direction.

  A stator comprising three-phase stator magnetic poles and stator windings, three-phase stator magnetic poles arranged in the circumferential direction, and each phase comprising two rows of stator windings as the center in the circumferential direction A rotating electric machine having a stator wound around magnetic poles and having the three-phase stator magnetic poles magnetically divided, wherein the number of stator magnetic poles is a multiple of six.

  An object of the present invention is to provide a rotating electrical machine having a structure that hardly receives magnetic interference of each phase and a high output density.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows one embodiment of the present invention in which stator magnetic poles are magnetically arranged in three phases independently, and the permanent magnets of rotor magnetic poles are configured in two rows. The rotor has 24 poles. First, the configuration will be described. In the rotor 100, the shaft 1 is disposed at the center, and the rotor yoke 2 is disposed on the outer periphery of the shaft 1. A permanent magnet 3 is disposed on the outer periphery of the rotor yoke 2. The permanent magnet 3 is composed of two ring magnets, permanent magnets 3a and 3b. As shown in the figure, the permanent magnets 3a and 3b are configured such that the phase of the magnetized magnetic pole has an electrical angle and a phase difference. Originally, a support mechanism such as a case and a bearing is necessary as a motor, but it is omitted in this figure. Next, the stator 200 will be described. Three magnetic poles are arranged on the outer peripheral portion of the permanent magnet 3 of the rotor via a slight gap so that the stator magnetic pole has a phase difference of three phases. The three-phase stator magnetic poles are a U-phase magnetic pole 4U, a V-phase magnetic pole 4V, and a W-phase magnetic pole 4W, and are arranged so as to substantially overlap the permanent magnet 3 of the rotor. A stator coil is arranged at the center of each phase magnetic pole, the U phase coil is indicated by 5 U, the V phase coil is indicated by 5 V, and the W phase magnetic pole is indicated by 5 W. Furthermore, each phase coil forms a coil end portion in a U shape at the end of the stator magnetic pole, and lead wires 10U, 10V (not shown) and 10W are connected to an external drive circuit (not shown) from the coil end portion. Connected. In such a stator configuration, each stator magnetic pole is arranged on the outer periphery of the rotor with a phase difference of 120 degrees in electrical angle by a connecting material (not shown). The connecting material may have any structure as long as it can mechanically fix the stator magnetic poles of each phase, and is preferably composed of a nonmagnetic metal. Further, after being connected, it may be molded into a cylindrical shape by resin.

Details of the stator magnetic pole 4U described in FIG. 1 will be described with reference to FIG. Since the other phases, 4V and 4W, have the same structure, description thereof is omitted. As described above, the U-phase magnetic pole 4U is composed of five parts. The stator magnetic pole 4U is composed of two magnetic pole rows of 4Ua and 4Ub. For example, the 4Ua magnetic pole array is composed of magnetic pole teeth 4Ua1 arranged toward the inner peripheral side and 4Ua2 arranged outwardly. It is comprised so that it may be inserted | pinched. Furthermore, the other coil of the U-phase coil 5U is sandwiched between the central portions of 4Ub1 and 4Ub2 constituting another magnetic pole row 4Ub. The lead wire 10U of the U-phase coil 5U is taken out from a U-shaped coil end portion that is not sandwiched between magnetic poles.

  FIG. 3 (a) shows a structure in which a U-phase coil 5U is sandwiched between 4Ub rows of U-phase magnetic poles described above. The 4Ua row of magnetic poles are arranged in the coil portion in front of the page. FIG. 3B shows a magnetic pole at the center of the coil around which the U-phase coil 5U is wound. The U-phase coil 5U may be directly wound around the illustrated outward-facing magnetic pole teeth 4Ua2 and 4Ub2, or may be arranged in a horseshoe shape. It is also possible to manufacture 4Ua2 and 4Ub2 integrally.

FIG. 4 shows a completed view of the U-phase magnetic pole 4U. As described above, the U-phase coil 5U is arranged at the center of the magnetic pole array composed of two rows. As can be seen from the figure, the magnetic pole teeth constituting the magnetic pole row 4Ua are formed in the same shape. Similarly, the other magnetic pole row 4Ub is formed of substantially the same shape.

  FIG. 5 (a) shows a view in which a notch 7 is provided in the portion between the magnetic poles that overlaps the tip portions of the outward magnetic pole teeth 4Ua2 and 4Ub2 of the U-phase magnetic pole 4U described above. The shape of the notch 7 is a circle or a rectangle, and the width W2 of the notch 7 is narrower than the width W1 between the magnetic poles, and preferably equal to the tip width W3 of the magnetic pole teeth. Here, the reason why the notch portion 7 is provided is that the distance from the claw tip portion to the portion between the magnetic poles is increased, and therefore, in addition to the reduction of the leakage magnetic flux from the claw tip portion, there is an effect of reducing the coil inductance. In this case, the generated current can be increased, and in the case of a motor, the motor voltage can be reduced. FIG. 5B shows another embodiment in which the same effect can be expected. FIG. 5B is a view in which a hollow portion 8 is provided between the magnetic poles. Although the effect of reducing leakage magnetic flux from the claw tip cannot be expected as an effect, the mechanical strength can be increased because the coil inductance is reduced and the inner peripheral side between the magnetic poles is connected. Furthermore, you may comprise combining these two. Other methods of using these notches 7 and cutouts 8 will be described. As described above, since the three-phase magnetic poles are magnetically separated, it is necessary to fix them in the radial direction and the circumferential direction. Furthermore, it is necessary to ensure an electrical phase difference with high accuracy as a three-phase rotating electrical machine. Therefore, it is possible to fix the cutout portion 7 and the cutout portion 8 by using them for positioning. The size of the cut-out portion 8 is preferably about W1 between the magnetic pole widths even if it is large if the width of the cut-out portion is W4 as in the previously described notch portion.

  The magnetic pole shape shown in FIG. 2 is realized by pressing magnetic powder (compression molding), but it can be made by bending an iron plate or using magnetic materials. It is also possible to produce with a sintered material. Furthermore, it is also possible to realize a structure in which magnetic pole teeth made in a ring shape are combined by cutting in a necessary number.

  Next, the relationship between the number of rotor poles and the number of stator magnetic poles in the circumferential magnetic pole arrangement motor of the present invention will be described. In the above description, the rotor is composed of 24 poles and the stator magnetic poles are composed of 6 pieces per phase. If the number of one-phase magnetic poles is six, then in the case of a three-phase motor, the total number of magnetic poles is eighteen. Since the pole pitch of the magnet of the present invention and the pole tooth pitch of the stator magnetic pole are substantially equal, when the number of rotor poles is 24 and the total number of stator poles is 18, (18/24 = 0.75) It can be considered as a combination in which 75% of magnetic flux can be used for the rotor magnet. In order to divide the stator magnetic pole and configure the coil end on the divided end face, the number of permanent magnet poles and the number of three-phase stator magnetic poles cannot be made equal. The sum needs to be small. If the number of stator magnetic poles is too small, the gap between the phases becomes large and the magnetic flux utilization rate of the magnet decreases. The fact that the magnetic flux utilization rate is low can be considered as a reduction in output density as a motor, and it can be said that the motor is not a very good motor. Thus, the relationship between the number of magnet poles of the rotor and the total number of magnetic poles of the stator is summarized in FIG. The vertical axis of the table is the number of rotor poles, and the horizontal axis is the total number of stator magnetic poles. As described above, when the number of poles P is equal to the number of total magnetic poles S, the combination of magnetic poles cannot be selected because the stator magnetic poles are not established. Further, even when the total number of magnetic poles S is larger than the number of poles P, it is not possible to achieve a combination that cannot be realized. Further, when the total number of magnetic poles S is smaller than the number of poles P, the utilization rate of the permanent magnets is lowered, which is not so good. Therefore, in the present invention, when the total number of magnetic poles S / number of poles P is considered to be about 0.67 (about 2/3) as the lowest line, a combination that has a good relationship between the number of poles P and the total number of magnetic poles S. It turns out that there is. First, regarding the number of poles P, the minimum number of stator poles S is 2 x 3 phases = 6 is the minimum combination, so the number of poles is the minimum combination of 8 poles. Therefore, it can be seen that the structure of the present invention is not established unless it is 8 poles or more.

Next, regarding the total number S of the stator magnetic poles, since the two magnetic poles are three phases and three phases, the minimum number is six. Therefore, it is understood that the total number of stator magnetic poles is not established unless it is a multiple of six. The combination in consideration of these two conditions and the utilization rate is a portion indicated by a triangle, and the combination that further holds is a shaded portion. In other words, the magnetic flux utilization rate is highest when the number of poles P is −2 with respect to the total number S of magnetic poles, and the utilization rate increases as the number of poles increases. When the magnetic flux utilization factor is 0.67 or more, the number of poles P is 8, 14, 16, 18,... 60 poles. Further, combinations having a utilization rate of 90% or more are combinations with 付 い in the determination column beside the number of poles on the vertical axis in FIG. If this combination of ◎ can be selected, characteristic deterioration due to division in the circumferential direction can be minimized. The number of poles in the table is 20, 26, 32, 38, 40, 44, 46, 50,
52, 56, 58, 60 poles.

  In the above description, the minimum line of the magnetic flux utilization factor is set to 0.67, but the magnetic flux utilization factor may be reduced due to the relationship between the magnetic pole sensors arranged between the poles and the connecting members connecting the magnetic poles. In that case, since the performance can be maintained by setting the residual magnetic flux density of the permanent magnet used high or extending the axial length, the structure of the present invention can be realized even when the magnetic flux utilization rate is 0.67 or less. As described above, a motor having a high output density can be provided by properly selecting the relationship between the total number of rotor poles and the total number of stator magnetic poles.

  In the embodiments so far, the stator magnetic poles are arranged in two rows, but the structure of the embodiment of the rotating electrical machine shown in FIG. 7 arranged in one row is also conceivable. The stator core is arranged at three locations in three phases, and the stator coil is configured to circulate in the outer diameter direction on the opposite side of the magnetic pole teeth after passing through the inside of the magnetic pole. In this way, by forming the stator magnetic poles in a single row, there is an effect that the axial thickness can be reduced. In addition, since about half of the stator coil protrudes from the magnetic pole, there is an effect that the cooling efficiency can be improved by applying cooling air to the protruding portion. In the present embodiment, a three-phase structure is described, but a single-phase, two-phase, five-phase, etc. may be used. In addition, the present embodiment can be similarly realized by compression molding of magnetic powder, but it can also be made by bending an iron plate or made of a sintered magnetic material. Furthermore, it is also possible to realize by forming the stator magnetic poles in a ring shape and cutting and combining them in the required number.

  Further, in all of the embodiments so far, the inner rotating type rotating electric machine has been described, but an outer rotating type rotating electric machine may be used, and the same effect is obtained. The rotating electric machines of all the embodiments so far are a kind of claw pole type rotating electric machines.

  Further, in the present invention, the relationship between the number of poles of the permanent magnet of the rotor and the number of poles of the stator magnetic pole is shown. However, the number of poles of the claw magnetic pole of the rotor used in the in-vehicle alternator and the number of poles of the stator of the present invention. Needless to say, the relationship is similar.

The motor structure perspective view of the 1st example of the present invention. The component figure which showed the components which comprise the stator magnetic pole of this invention. The division figure of the stator magnetic pole of this invention. The perspective view for one phase of the stator magnetic pole of the present invention. The perspective view for one phase of the stator magnetic pole of the present invention. The relationship table of the number of motor poles of this invention and the number of stator magnetic poles. The rotary electric machine of the other Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shaft 2 Rotor yoke 3 Permanent magnet 4 Stator magnetic pole 5 Coil 6 Magnetic pole sensor 7 Notch part 8 Cut-out part 10 Magnetic pole end surface 100 Rotor 200 Stator

Claims (11)

A rotor composed of a plurality of permanent magnets on the outer peripheral surface;
It consists of three-phase stator poles and stator windings,
Place three-phase stator poles in the circumferential direction,
Each phase is wound around a stator pole composed of two rows of stator windings as the center in the circumferential direction,
And a rotating electric machine having a stator in which the three-phase stator magnetic poles are magnetically divided,
The rotating electrical machine is characterized in that the number of stator magnetic poles is a multiple of six. In claim 1,
The rotating electric machine is characterized in that the rotor has eight or more poles. In claim 1,
The rotating electrical machine is characterized in that the rotor has 14 or more poles. In claim 1,
The number of poles of the rotor is 20, 26, 32, 38, 40, 44, 46, 50, 52, 56, 58, or 60 poles. The rotating electric machine according to claim 1, wherein the stator magnetic pole is made of magnetic powder. In claim 1,
The rotating electrical machine is characterized in that the number of poles of the rotor is two larger than the number of stator magnetic poles. A rotor composed of a plurality of permanent magnets on the outer peripheral surface;
It consists of a stator pole and a stator winding,
Place multiple-phase stator poles in the circumferential direction,
Each phase is wound around a stator pole composed of two rows of stator windings as the center in the circumferential direction,
And the rotating electric machine having a stator in which the stator poles of the plurality of phases are magnetically divided,
A rotating electrical machine having a notch portion or a cutout portion between stator magnetic poles. In Claim 7, The said stator magnetic pole is comprised with the magnetic powder, The rotary electric machine characterized by the above-mentioned. A rotor composed of a plurality of permanent magnets on the outer peripheral surface;
It consists of a stator pole and a stator winding,
Place multiple-phase stator poles in the circumferential direction,
Each phase is wound around a stator pole composed of a single row of stator windings as the circumferential center,
And a rotating electric machine having a stator in which the plurality of stator magnetic poles are magnetically divided. The rotary electric machine according to claim 9, wherein the stator magnetic pole is made of magnetic powder. In claim 9,
The rotating electric machine according to claim 1, wherein the plurality of phases are single phase, two phase, three phase, and five phase.

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