JP2003018770A - Rotating electric machine - Google Patents

Abstract

(57) [Problem] To provide a rotating electric machine capable of reducing cogging torque and suppressing a decrease in generated torque. A stator core gap surface (12) extends in an axial direction,
In addition, an auxiliary groove 11 having a circumferential inclination is provided. The groove center of the auxiliary groove 11 is configured to protrude toward the center. Further, a slot cover 14 is provided in a slot between the stator magnetic poles. The slot lid 14 has a long opening 15 extending in the axial direction and inclined in the circumferential direction.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a rotating electric machine,
In particular, the present invention relates to a rotating electric machine having a structure capable of reducing pulsating torque.

[0002]

2. Description of the Related Art In a permanent magnet field type rotary electric machine, there is a problem that a cogging torque is generated due to a magnetic fluctuation in a gap between a stator and a rotor, and smooth rotation is hindered. Therefore, for example, Japanese Patent Laid-Open No. 2-219453
As described in Japanese Patent Publication No. JP-A-2003-264, in addition to forming a notch extending in the axial direction at the magnetic pole tip of the stator magnetic pole,
It is known that this cut is inclined in the rotational direction. By providing this notch, it is possible to disperse and correct the disturbance of the magnetic flux distribution in the void portion and reduce the cogging torque.

[0003]

However, in the one disclosed in Japanese Patent Application Laid-Open No. 2-219453, since the notch is provided in the stator magnetic pole, the effective magnetic flux amount that the windings interlink is reduced. The first problem is that the generated torque is reduced.

Further, there is a second problem that the manufacturing process is complicated because a step of forming a notch in the magnetic pole tip portion of the stator magnetic pole is required.

A first object of the present invention is to provide a rotating electric machine capable of reducing the cogging torque and suppressing the reduction of the generated torque.

A second object of the present invention is to provide a rotating electric machine that can reduce cogging torque and is easy to manufacture.

[0007]

(1) In order to achieve the above first object, the present invention provides a stator having a multi-phase stator winding wound around a stator magnetic pole of a stator core. , A rotating electric machine having a rotor rotatably arranged with respect to the stator, extending axially in the stator core void surface,
And with an auxiliary groove that has an inclination in the circumferential direction,
The central portion of the auxiliary groove is configured to project toward the central portion. With this configuration, the cogging torque can be reduced and the reduction of the generated torque can be suppressed.

(2) In order to achieve the above second object,
The present invention relates to a rotating electric machine having a stator having a multi-phase stator winding wound around a stator magnetic pole of a stator core, and a rotor rotatably arranged with respect to the stator, The slot lid is provided in the slot between the stator magnetic poles, and the slot lid has a long opening extending in the axial direction and inclined in the circumferential direction. With this configuration, the cogging torque can be reduced and the manufacturing can be easily performed.

(3) In the above (2), preferably,
The stator core void surface is provided with an auxiliary groove extending in the axial direction and having an inclination in the circumferential direction, and the groove center portion of the auxiliary groove is made to project toward the center portion. .

(4) In the above (3), preferably,
The long opening and the auxiliary groove are inclined in the same circumferential direction.

(5) In above (3), preferably,
The long opening and the auxiliary groove are inclined in a V-shape in the opposite direction to the circumferential direction.

(6) In the above (3), preferably,
The axial length of the long opening is longer than the axial length of the auxiliary groove.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The configuration of a rotary electric machine according to a first embodiment of the present invention will be described below with reference to FIGS. First, the overall configuration of the rotary electric machine according to the present embodiment will be described with reference to FIG. FIG. 1 shows the first of the present invention.
FIG. 3 is a side view showing the overall configuration of the rotating electric machine according to the embodiment book.

The electric motor 1 is composed of a stator 2 and a rotor 3. The stator 2 includes a housing (not shown), a stator core 4 fixed to the inner peripheral surface of the housing,
It is composed of a multi-phase stator winding 5 wound around a stator core 4. Here, the stator core 4 is composed of an annular stator yoke 6 and a stator magnetic pole 7. The stator winding 5 is concentratedly wound around the stator magnetic pole 7. The windings 5 are configured so as not to share a magnetic path on the air gap surface. With the concentrated winding stator structure, the length of the winding end can be shortened compared to the distributed winding stator used in general large machines, etc., and the overall size of the rotating electric machine can be reduced. You can

The rotor 3 includes a permanent magnet 8, a yoke 9 and
And a shaft 10. The shaft 10 is rotatably held by the stator 2 by bearings, end brackets, and the like (not shown). Where Hu, Hv, Hw are
A magnetic pole position detector (generally constituted by a Hall element or the like) for detecting the position of the permanent magnet of the rotor 3 is shown. Stator winding U1 +, U1-, U2 +, U2-, V1 +, V1-, V2 +, V
A pair of magnetic pole position detectors Hu, Hv, Hw corresponding to 2-, W1 +, W1-, W2 +, W2- is arranged. Here, the magnetic pole position detector H
u, Hv, and Hw are targeted for the magnetic pole position detector configured to directly detect the magnetic pole position by the magnetic flux generated by the permanent magnet 8 of the rotor 3.

The illustrated rotating electric machine has three phases, the permanent magnet rotor 3 has 10 poles, and the stator has 12 magnetic poles. That is, it is a permanent magnet field type rotary electric machine in which the ratio of the number of permanent magnet poles to the number of stator poles is 5: 6. Here, an example of an electric motor is shown as the rotating electric machine, but the same applies to a generator. Furthermore, although the concentrated winding structure is shown here, the structure is not limited to the concentrated winding structure and can be applied to a stator having a distributed winding structure, and the ratio of the number of permanent magnet poles to the number of stator poles can also be applied. It is not limited.

Further, in this embodiment, the auxiliary groove 1
One is provided on the air gap surface 12 of the stator magnetic pole 7. The auxiliary groove 11 is configured so as to extend in the axial direction and further have a certain inclination in the circumferential direction, as will be described later with reference to FIG.

Next, the structure of the auxiliary groove provided at the magnetic pole tip of the stator magnetic pole of the rotating electric machine according to this embodiment will be described with reference to FIGS. 2 and 3. FIG. 2 is a development view showing the configuration of auxiliary grooves provided in the stator poles of the rotating electric machine according to the first embodiment of the present invention. It should be noted that FIG. 2 is an expanded view of the stator magnetic pole tip portion having the auxiliary groove formed, as viewed from the rotor side. Further, FIG. 3 shows the first aspect of the present invention.
FIG. 6 is a partially enlarged side view showing the configuration of auxiliary grooves provided in the stator magnetic poles of the rotating electric machine according to the embodiment of FIG. The same reference numerals as those in FIG. 1 denote the same parts.

As shown in FIG. 2, the auxiliary groove 11 has a structure extending in the axial direction (arrow X direction) with a uniform width and having an inclination in the circumferential direction (arrow Y direction).

Further, as shown in FIG.
The groove bottom portion 13 of the auxiliary groove 11 extending in the axial direction and inclined in the circumferential direction, which is provided at the tip portion 12, has a structure protruding toward the rotor side (downward in the drawing). The protrusion of the groove bottom is not limited to the arc shape, but may be a triangular shape, a trapezoidal shape, or any other polygonal shape as long as there is a difference between the groove side portion and the central portion.

Next, the effect of reducing the cogging torque in the rotary electric machine according to this embodiment will be described with reference to FIG. FIG. 4 is an explanatory diagram of the effect of reducing the cogging torque in the rotary electric machine according to the first embodiment of the present invention. FIG. 4 shows a torque ripple basic waveform in order to show the fluctuation of the cogging torque.

FIG. 4A shows a waveform of the cogging torque when the auxiliary groove 11 is not provided. The cogging torque without the auxiliary groove 11 appears at 60 cycles / revolution, which is the least common multiple of the number of permanent magnet poles of 10 and the number of stator poles of 12. Brushless motors are used in various fields, but when used in a hood fan in particular, noise generated by a slight pulsating torque of a rotating electric machine is amplified by the hood and becomes large noise.

FIG. 4B shows the waveform of the cogging torque when one auxiliary groove 11 having substantially the same magnetic resistance as the gap between the stator magnetic poles is provided on the gap surface of the stator magnetic poles. There is. As shown in FIG. 1, if one auxiliary groove 11 having substantially the same magnetic resistance as the gap between the stator magnetic poles is provided on the gap surface of the stator magnetic poles, the gap between the stator magnetic poles 7 becomes 2
It becomes the same as 24 times, and the least common multiple of the number of permanent magnet poles and the number of stator magnetic poles is 120 cycles / revolution, and it is possible to increase the pulsation number per rotation and reduce the cogging torque. it can.

FIG. 4 (c) shows the waveform of the cogging torque when the auxiliary groove 11 provided in the air gap surface of the stator magnetic pole is inclined in the circumferential direction. In the present embodiment, the auxiliary groove 11
Has a structure having an equal width in the axial direction and an inclination in the circumferential direction, so that the iron core is skewed at the portion of the auxiliary groove 11, and the waveform peak value of the pulsating torque can be blunted. As a result, the cogging torque is shown in FIG.
As shown in (c), the average pulsation value can be further reduced.

Further, in this embodiment, the groove bottom portion 13 of the auxiliary groove 11 is formed to project to the rotor side (downward in the figure). Generally, when the auxiliary groove is provided, the amount of effective magnetic flux interlinking the windings is slightly reduced, so that the generated torque is reduced. However, by adopting the protruding structure, the change in reactance occurs at the side wall portion of the groove, so the pulsation number increases, and since the protrusion of the groove central portion can prevent the reduction of the magnetic flux amount, it is possible to suppress the decrease in the generated torque. it can.

As described above, according to this embodiment, the cogging torque can be reduced and the reduction of the generated torque can be suppressed.

Next, the structure of the rotary electric machine according to the second embodiment of the present invention will be described with reference to FIGS. 5 and 6. The overall configuration of the rotary electric machine according to this embodiment is the same as that shown in FIG. FIG. 5 is a development view showing the configuration of auxiliary grooves provided in the stator poles of the rotating electric machine according to the second embodiment of the present invention. Note that FIG. 5 is an expanded view of the stator magnetic pole tip portion having the auxiliary groove formed, as viewed from the rotor side. Further, FIG. 6 is a cross-sectional view showing the structure of the opening provided in the slot lid of the rotary electric machine according to the second embodiment of the present invention. The same reference numerals as those in FIGS.
The same part is shown.

A slot lid 14 made of a magnetic material is arranged in the slot opening between the adjacent stator magnetic poles 12. Further, the stator magnetic pole 7 is provided at the center of the slot lid 14.
An elongated opening 15 extending in the axial direction and inclined in the circumferential direction is provided in the tip portion 12 of the.

The long opening 15 provided in the slot lid 14 and inclined in the circumferential direction can smooth the waveform peak value of the pulsating torque, similarly to the auxiliary groove 11 shown in FIG. As a result, the cogging torque is, as shown in FIG.
It is possible to further reduce the average pulsation value.

Here, the long opening 1 provided in the slot lid 14
Since No. 5 can be formed by cutting the slot lid 14 or the like, it is easier to form than the auxiliary groove 11 shown in FIG. 2 and the workability is improved.

Therefore, according to this embodiment, the cogging torque can be reduced and the manufacturing can be facilitated.

Next, the structure of the rotating electric machine according to the third embodiment of the present invention will be described with reference to FIG. The overall configuration of the rotary electric machine according to this embodiment is the same as that shown in FIG. FIG. 7 is a development view showing the configuration of auxiliary grooves provided in the stator poles of the rotating electric machine according to the third embodiment of the present invention. Note that FIG. 7 is an expanded view of the stator magnetic pole tip portion having the auxiliary groove formed, as viewed from the rotor side. The same reference numerals as those in FIGS. 1 to 3, 5 and 6 denote the same parts.

In this embodiment, similarly to the embodiment shown in FIG. 2, the tip portion 12 of the stator pole 7 is provided with an auxiliary groove 11 extending in the axial direction and inclined in the circumferential direction. Here, as shown in FIG. 3, the groove bottom portion of the auxiliary groove 11 has a structure protruding toward the rotor side (downward in the drawing).

As described with reference to FIGS. 5 and 6, a slot lid 14 made of a magnetic material is arranged in the slot opening between the adjacent stator magnetic poles 12. At the center of the slot lid 14, there is provided a long opening 15 provided in the tip portion 12 of the stator pole 7 and extending in the axial direction and inclined in the circumferential direction.

Further, the auxiliary groove 11 and the long opening 15 formed in the slot lid 14 are respectively formed in the circumferential direction.
It is tilted in the same direction and has a 1/2 slot skew configuration.

The axial length L1 of the long opening 15 provided at the center of the slot lid 14 is longer than the axial length L2 of the auxiliary groove 11 provided at the tip 12 of the stator pole 7. is doing. With this configuration, the influence of magnetic flux leakage can be eliminated.

With this structure, the cogging torque generated between the magnetic poles of the stator and the cogging torque generated by the auxiliary slot are made uniform, so that a torque ripple equivalent to that in the case where a one-slot skew is applied can be reduced. The basic waveform of the cogging torque at this time is as shown in FIG. 4D, and the pulsating torque can be further reduced.

Further, by making the groove bottom portion 13 of the auxiliary groove 11 project toward the rotor side (downward in the figure),
Since the change in reactance occurs at the side wall of the groove, the number of pulsations increases, and the protrusion of the groove center can prevent the decrease in the amount of magnetic flux, so that the decrease in generated torque can be suppressed.

Further, the long opening 1 provided in the slot lid 14
Since No. 5 can be formed by cutting the slot lid 14 or the like, it is easier to form and the workability is improved as compared with the case where two auxiliary grooves are formed at the magnetic pole tip of one stator magnetic pole. It is a thing.

As described above, according to this embodiment, the cogging torque can be further reduced, the reduction of the generated torque can be suppressed, and the manufacturing can be facilitated.

Next, the structure of the rotating electric machine according to the fourth embodiment of the present invention will be described with reference to FIG. The overall configuration of the rotary electric machine according to this embodiment is the same as that shown in FIG. FIG. 8 is a development view showing the configuration of auxiliary grooves provided in the stator poles of the rotating electric machine according to the fourth embodiment of the present invention. It should be noted that FIG. 8 is an exploded view of the stator magnetic pole tip portion having the auxiliary groove formed, as viewed from the rotor side. The same reference numerals as those in FIGS. 1 to 3, 5 and 6 denote the same parts.

In this embodiment, similarly to the embodiment shown in FIG. 2, the tip portion 12 of the stator pole 7 is provided with an auxiliary groove 11 extending in the axial direction and inclined in the circumferential direction. Here, as shown in FIG. 3, the groove bottom portion of the auxiliary groove 11 has a structure protruding toward the rotor side (downward in the drawing).

As described with reference to FIGS. 5 and 6, the slot lid 14 made of a magnetic material is arranged in the slot opening between the adjacent stator magnetic poles 12. Further, in the center of the slot lid 14, a long opening 15A extending in the axial direction and provided in the tip portion 12 of the stator magnetic pole 7 and inclined in the circumferential direction is formed.
Is provided.

Further, the auxiliary groove 11 and the long opening 15A formed in the slot lid 14 are inclined in opposite directions in the circumferential direction, and are arranged in a V shape, and have a 1/2 slot skew. It is configured. With this configuration, it is possible to cancel the axial attraction force (which acts in the vertical direction in the figure) caused by the skew, and it is possible to reduce the cogging torque without generating the axial thrust force.

The axial length L1 of the long opening 15 provided in the central portion of the slot lid 14 is longer than the axial length L2 of the auxiliary groove 11 provided at the tip portion 12 of the stator pole 7. is doing. With this configuration, the influence of magnetic flux leakage can be eliminated.

With this structure, the cogging torque generated between the magnetic poles of the stator and the cogging torque generated by the auxiliary slot are made uniform, so that the torque ripple equivalent to that in the case where the one-slot skew is applied can be reduced. The basic waveform of the cogging torque at this time is as shown in FIG. 4D, and the pulsating torque can be further reduced.

Further, by making the groove bottom portion 13 of the auxiliary groove 11 project toward the rotor side (downward in the figure),
Since the change in reactance occurs at the side wall of the groove, the number of pulsations increases, and the protrusion of the groove center can prevent the decrease in the amount of magnetic flux, so that the decrease in generated torque can be suppressed.

Further, the long opening 1 provided in the slot lid 14
Since No. 5 can be formed by cutting the slot lid 14 or the like, it is easier to form and the workability is improved as compared with the case where two auxiliary grooves are formed at the magnetic pole tip of one stator magnetic pole. It is a thing.

As described above, according to this embodiment, the cogging torque can be further reduced, the reduction of the generated torque can be suppressed, and the manufacturing is facilitated.

Next, the structure of the rotating electric machine according to the fifth embodiment of the present invention will be described with reference to FIGS. 9 and 10. FIG. 9 is a side view showing the overall configuration of a rotary electric machine according to the fifth embodiment of the present invention. Further, FIG. 10 is a sectional view showing a configuration of an opening and an auxiliary groove provided in the slot lid of the rotating electric machine according to the fifth embodiment of the present invention.

The rotary electric machine 1A in this embodiment shown in FIG. 9 is an induction motor. Generally, slot ripple occurs not only in the case of a permanent magnet field but also in the case of an induction machine. That is, when the magnetic flux passes through the presence of the magnetic substance and the non-magnetic substance such as the stator magnetic pole 7 and the stator winding 5 and the rotor yoke 9 and the secondary conductor 16 across the gap, the reactance of The change causes a torque ripple. This ripple component can be considerably reduced by skewing the conductor portion on either the stator side or the rotor side by one slot. Therefore, in this embodiment,
An auxiliary groove 13 is provided at the tip portion 12 of the stator magnetic pole 7 so as to be inclined in the circumferential direction. With this structure, the pulsating torque can be reduced without skewing on the stator side and the rotor side. Note that reference numeral 18 is an air hole.

Further, as shown in FIG. 10, a slot lid 14A made of a magnetic material is arranged in the slot opening portion between the adjacent stator magnetic poles 12. Also, the slot lid 1
At the center of 4A, there is provided a long opening 15 provided in the tip portion 12 of the stator magnetic pole 7, extending in the axial direction and inclined in the circumferential direction.

The elongated opening 15 provided in the slot lid 14A and inclined in the circumferential direction can smooth the peak value of the pulsating torque waveform, similarly to the auxiliary groove 11 shown in FIG. As a result, the cogging torque can further reduce the average pulsation value as shown in FIG.

Since the long opening 15 provided in the slot lid 14A can be formed by cutting the slot lid 14A, it can be formed more easily than the auxiliary groove 11 shown in FIG. Workability is improved. In addition,
The auxiliary groove 14 can be formed by punching the groove while shifting the notching process when punching the magnetic pole core, and can be obtained by stacking core iron plates whose groove positions are shifted to form a stator core. This can be formed in exactly the same manner in the case of the permanent magnet field type rotary electric machine shown in FIGS.

[0055]

According to the present invention, the cogging torque can be reduced and the reduction of the generated torque can be suppressed.

Further, the cogging torque can be reduced and the manufacturing can be easily performed.

[Brief description of drawings]

FIG. 1 is a side view showing an overall configuration of a rotary electric machine according to a first embodiment of the present invention.

FIG. 2 is a development view showing a configuration of an auxiliary groove provided in a stator magnetic pole of the rotating electric machine according to the first embodiment of the present invention.

FIG. 3 is a partially enlarged side view showing a configuration of an auxiliary groove provided in a stator pole of the rotating electric machine according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of a cogging torque reduction effect in the rotary electric machine according to the first embodiment of the present invention.

FIG. 5 is a development view showing a configuration of auxiliary grooves provided in a stator pole of a rotating electric machine according to a second embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a configuration of an opening provided in a slot lid of a rotary electric machine according to a second embodiment of the present invention.

FIG. 7 is a development view showing a configuration of auxiliary grooves provided in a stator pole of a rotating electric machine according to a third embodiment of the present invention.

FIG. 8 is a development view showing a configuration of auxiliary grooves provided in a stator pole of a rotating electric machine according to a fourth embodiment of the present invention.

FIG. 9 is a side view showing the overall configuration of a rotary electric machine according to a fifth embodiment of the present invention. Also,

FIG. 10 is a sectional view showing a configuration of an opening and an auxiliary groove provided in a slot lid of a rotary electric machine according to a fifth embodiment of the present invention.

[Explanation of symbols]

1 ... Permanent magnet rotating electric machine 2 ... Stator 3 ... rotor 4 ... Stator core 5 ... Stator winding 6 ... Stator yoke 7 ... Stator magnetic pole 8 ... Permanent magnet 9 ... Rotor yoke 10 ... Shaft 11 ... Auxiliary groove 12 ... Stator magnetic pole tip 13 ... Bottom of groove 14 ... Slot lid 15 ... Long opening 16 ... Rotor secondary conductor 17 ... Stator side slot 18 ... Ventilation

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5H002 AA09 AB01 AB06 AE06 AE07                 5H019 AA03 BB01 BB05 BB13 CC03                       DD01 EE01 EE04                 5H621 AA02 BB07 BB10 GA01 GA04                       GA12 GA14 PP10

Claims (6)

[Claims] 1. A rotary electric machine having a stator having a multi-phase stator winding wound around a stator magnetic pole of a stator core, and a rotor rotatably arranged with respect to the stator. The stator core void surface is provided with an auxiliary groove extending in the axial direction and having an inclination in the circumferential direction, and the groove center portion of the auxiliary groove is configured to project toward the center portion. And rotating electrical machinery. 2. A rotating electric machine comprising a stator having a multi-phase stator winding wound around a stator magnetic pole of a stator core, and a rotor rotatably arranged with respect to the stator. A rotary electric machine comprising: a slot lid arranged in a slot between the stator magnetic poles; the slot lid having a long opening extending in the axial direction and having an inclination in the circumferential direction. 3. The rotating electric machine according to claim 2, further comprising an auxiliary groove extending in the axial direction and inclined in the circumferential direction in the stator core void surface, and the groove central portion of the auxiliary groove. The rotating electrical machine according to claim 1, wherein the rotating electric machine is configured so as to project toward the center. 4. The rotary electric machine according to claim 3, wherein the long opening and the auxiliary groove are inclined in the same circumferential direction. 5. The rotating electric machine according to claim 3, wherein the long opening and the auxiliary groove are inclined in a V-shape in a direction opposite to a circumferential direction. 6. The rotary electric machine according to claim 3, wherein the length of the long opening in the axial direction is longer than the length of the auxiliary groove in the axial direction.