JP2010068595A - Stator of synchronous motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stator of a synchronous motor, which can suppress vibration and noise, and reduce distortion in induced voltage. <P>SOLUTION: The stator of the synchronous motor includes a stator core 10 formed by laminating magnetic steel plates and a winding wound around the stator core 10 and electrified. The stator core 10 includes: a plurality of teeth parts 1 projecting toward a rotor rotating inside the stator of the synchronous motor; the opposing part 1a of the rotor opposite to the rotor, forming a part of the teeth parts 1; and a non-magnetic space 2 provided inside the opposing part 1a of the rotor and gradually increasing in volume toward the circumferential both ends from the circumferential center portion. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a stator of a synchronous motor that uses a permanent magnet for a rotor.

  In a synchronous motor that uses a permanent magnet for the rotor, the magnetic flux generated in the rotor is linked to the stator winding, and the current is supplied to the winding from the outside to generate torque that rotates the rotor. appear. If the change in magnetic flux generated from the rotor and interlinked with the stator windings is not gradual, the torque output from the synchronous motor varies, and vibration and noise are generated from the synchronous motor.

  Further, in general, a stator core using a magnetic material that allows easy passage of magnetic flux is used for the stator in order to link the magnetic flux of the rotor to the windings. The winding of the stator is often wound around a tooth portion protruding from the stator core toward the rotor. In order to link the magnetic flux more to the winding, a slot opening is often provided between adjacent teeth. At this time, since the magnetic resistance is different between the rotor facing portion and the opening of the tooth portion, the magnetic flux generated from the rotor is unbalanced, and cogging torque is generated, which causes vibration and noise of the synchronous motor.

  In order to solve this problem, the following techniques have been proposed. In other words, a groove that penetrates in the axial direction is provided in a part of the stator tooth portion that faces the rotor to make a pseudo opening, thereby increasing the number of magnetically unbalanced portions and distributing energy. Thus, a rotating electrical machine that reduces cogging torque has been proposed (see, for example, Patent Document 1).

  In addition, in a motor having auxiliary grooves in the teeth of the stator core, even if the width of the auxiliary grooves slightly deviates from the ideal shape, the purpose is to reduce the cogging torque without changing the shape of the press die or the like. In a permanent magnet type motor that forms a stator by laminating stator cores with auxiliary grooves provided at positions facing the permanent magnets, the width of the auxiliary grooves, including zero, depends on the position of the stator core in the stacking direction. A permanent magnet type motor that reduces cogging torque by changing it has been proposed (see, for example, Patent Document 2).

  In addition, in a permanent magnet motor equipped with a closed slot type stator core, the stator core is a connection that connects adjacent teeth to the tip of the rotor side of each tooth in order to reduce torque ripple. It is a closed slot type having a portion, and two holes extending in the axial direction are provided near the tip of each tooth. The hole formed near the tip of the teeth becomes the magnetic resistance of the interlinkage magnetic flux that flows through the connecting portion during rotation of the rotor, making it difficult for the magnetic flux to flow to the connecting portion side, and the amount of interlinkage magnetic flux flowing through the connecting portion is abrupt. Change will be suppressed. As a result, a permanent magnet motor has been proposed in which the occurrence of distortion in the induced voltage waveform generated in the teeth (stator winding portion) is suppressed, and as a result, the occurrence of torque ripple can be suppressed as much as possible ( For example, see Patent Document 3).

Furthermore, in order to provide a motor with a small cogging torque without providing a groove in the stator core at a low cost, the tip of one side of the teeth portion of the stator core laminated to about 1/2 of the laminated thickness of the stator is pressurized to provide magnetic characteristics. Deteriorate. Similarly, pressurize the other tip of the stator core laminated about 1/2. A motor has been proposed in which two stator cores with pressure applied at the tip end are laminated so that the tip end portion and the tip end are point symmetric, the deteriorated portion of the magnetic properties becomes point symmetric, and an effect similar to skew is obtained ( For example, see Patent Document 4).
JP 62-77840 A JP 2006-230116 A JP 2006-288043 A JP 2005-168153 A

  However, as in Patent Document 1 and Patent Document 2 described above, providing a groove extending in the axial direction at the rotor facing portion of the stator tooth portion provides an effect of reducing cogging torque, but causes torque ripple. There is a problem that the effect of reducing the distortion of the induced voltage cannot be obtained.

  Further, in the case of the permanent magnet motor (synchronous motor) described in Patent Document 3, the effect of suppressing vibration and noise of the permanent magnet motor can be obtained by reducing the distortion of the induced voltage. In addition, since there is no slot opening, the occurrence of cogging torque is small, and the effect of suppressing vibration and noise of the permanent magnet motor can be expected. However, since the tips of adjacent teeth are connected, the amount of magnetic flux generated from the rotor is short-circuited at this connecting part and linked to the stator windings is reduced, and the output of the permanent magnet motor is reduced. There are challenges.

  Further, in the case of the motor (synchronous motor) described in Patent Document 4, an effect equivalent to skew is obtained at the rotor facing portion of the stator teeth, and cogging torque is reduced and induced voltage is reduced. This can reduce the vibration and noise of the motor, but when manufacturing the stator core, a part of the core is pressurized to deteriorate the magnetic properties, which increases processing costs. There is a problem of doing.

  This invention is made in order to solve the above subjects, and it aims at providing the stator of the synchronous motor which can suppress a vibration and noise, and can reduce distortion of an induced voltage.

A stator of a synchronous motor according to the present invention includes a stator core formed by laminating electromagnetic steel plates, and a stator of a synchronous motor including a winding wound around the stator core and energized with current. In
The stator core is
A plurality of teeth protruding toward the rotor rotating inside the stator of the synchronous motor;
Forming a part of the tooth portion and facing the rotor, a rotor facing portion;
A non-magnetic space provided inside the rotor facing portion and having a volume gradually increasing from the circumferential center to both circumferential ends.

  The stator of the synchronous motor according to the present invention includes a non-magnetic space whose volume gradually increases from the circumferential center to both ends in the circumferential direction inside the rotor facing portion. As a result, the change in the magnetic flux interlinked with the motor becomes gentle, the distortion of the induced voltage is suppressed, the torque pulsation is suppressed, and the vibration and noise of the synchronous motor can be suppressed.

Embodiment 1 FIG.
1 to 10 show the first embodiment, FIG. 1 is a perspective view of a stator core 10 of a synchronous motor, FIG. 2 is an enlarged perspective view of a tooth portion 1 of FIG. 1, and FIG. The perspective view (a) which expanded the rotor opposing part 1a of the tooth part 1, sectional drawing (b) of AE part, FIG. 4 is the perspective view which expanded the tooth part 1 of the stator core 10 of the modification 1, 5 is an enlarged perspective view of the rotor facing portion 1a of FIG. 4, FIG. 6 is an enlarged perspective view of the tooth portion 1 of the stator core 10 of Modification 2, and FIG. 7 is the rotor of the tooth portion 1 of FIG. The perspective view (a) which expanded the opposing part 1a, sectional drawing (b) of AE part, FIG. 8 is a figure which shows the induced voltage of the synchronous motor using the stator core 10 shown in FIG. 4, FIG. The figure which shows the cogging torque of the synchronous motor using the stator core 10, FIG. 10 is a figure which shows the result of the frequency component analysis of an induced voltage.

  The configuration of the stator core 10 of the synchronous motor will be described with reference to FIGS. 1 and 2. The stator of a synchronous motor is mainly composed of a stator core 10 formed by laminating electromagnetic steel sheets having a thickness of 0.1 to 1.5 mm, and windings (not shown) that conduct current. The

  The stator core 10 has a plurality of teeth 1 that protrude toward a rotor (not shown) that rotates inside the stator. In the example of FIG. 1, there are six tooth portions 1.

  At the tip (inner peripheral surface) of the tooth portion 1, there is a rotor facing portion 1 a that faces the rotor. The inner peripheral surface of the rotor facing portion 1a has a substantially arc shape in cross section perpendicular to the axial direction. When the arcs of the inner peripheral surfaces of the six rotor facing portions 1a are connected, a single circle is formed.

  Usually, the rotor facing portion 1a has a shape wider in the circumferential direction than the tooth portion 1 in order to collect more magnetic flux from the rotor.

  A winding (not shown) is inserted into the slot 3 (space) between the adjacent tooth portions 1. The larger the wire diameter is, the lower the resistance is, and the loss generated in the winding during energization is reduced. Therefore, the width (circumferential direction) of the tooth portion 1 is rotated so that the slot 3 between the tooth portions 1 becomes larger. The width is smaller than the width (circumferential direction) of the child facing portion 1a. A slot opening 3a is provided between adjacent teeth 1.

  Inside the rotor facing portion 1a, there are nonmagnetic spaces 2 at the four corners when viewed from the rotor. The shape of the nonmagnetic space 2 is a substantially right triangle as viewed from the rotor.

  The circumferential length of the nonmagnetic space 2 is gradually increased from the central portion in the axial direction of the rotor facing portion 1a toward both end portions in the axial direction. Since the overall dimension of the nonmagnetic space 2 in the radial direction is substantially the same, the volume of the nonmagnetic space 2 gradually increases from the axially central portion of the rotor facing portion 1a toward both axial end portions. In other words, the volume of the nonmagnetic space 2 gradually increases from the circumferential center of the rotor facing portion 1a toward both circumferential ends. That is, the nonmagnetic space 2 is the largest space at both axial end portions and circumferential end portions of the rotor facing portion 1a. As a result, the shape of the region of the rotor facing portion 1a in which many magnetic bodies (magnetic steel plates) are present is substantially octagonal to hexagonal when viewed from the rotor.

  When the rotor of the synchronous motor rotates, the area of the rotor facing portion 1a of the stator core 10 that faces the magnetic poles of the rotor is the same as that of the stator core 10 without the nonmagnetic space 2. It gradually increases in proportion to the angle.

  On the other hand, in the stator core 10 of the synchronous motor having the nonmagnetic space 2, in the region where there are many magnetic bodies (electromagnetic steel plates) opposed to the magnetic poles of the rotor at first with respect to the rotation angle of the rotor. The increase in area is small and the increase in area gradually increases.

  When there is no nonmagnetic space 2 in the rotor facing portion 1a of the stator core 10, the change in magnetic flux flowing from the rotor magnetic pole into the rotor facing portion 1a changes according to the magnetic flux distribution of the rotor magnetic pole.

  For example, in the case of a rotor magnetized in a radial orientation, the change in the magnetic flux between the magnetic poles is abrupt. Therefore, the change in the magnetic flux flowing into the rotor facing portion 1a of the stator core 10 is suddenly changed near the switching of the magnetic poles. Change.

  Further, in the case of a rotor in which a permanent magnet is arranged inside a magnetic body, the magnetic flux generated from the permanent magnet is freely changed in direction at the magnetic body portion on the outer periphery of the permanent magnet. As the rotor rotates, the magnetic flux suddenly concentrates on the rotor facing portion 1a at the same time as it faces the rotor facing portion 1a of the stator core 10, and therefore flows into the rotor facing portion 1a of the stator core 10. Magnetic flux fluctuates rapidly.

  As a result, the induced voltage generated in the stator windings is distorted, and the torque pulsation of the synchronous motor is increased, causing vibration and noise.

  In the stator core 10 of the synchronous motor according to the present embodiment, when the rotor rotates, the area where the rotor facing portion 1a of the stator core 10 faces the rotor magnetic pole is initially small, and the tooth portion 1 is centered. As the rotation progresses, the area increase gradually increases. Therefore, the sudden flow of magnetic flux into the tooth portion 1 is suppressed, distortion of the induced voltage generated in the winding is reduced, torque pulsation is suppressed, and a synchronous motor with less vibration and noise is obtained.

  Usually, the stator core 10 is often constructed by laminating electromagnetic steel plates, and the stator core 10 shown in FIG. 2 is a hole for punching out the electromagnetic steel plates for constituting the nonmagnetic space 2 in the rotor facing portion 1a. This shape can be realized by gradually changing the shape of each steel sheet to be laminated as shown in FIG.

  As shown in FIG. 3, the shape of the hole 2a forming the nonmagnetic space 2 of the laminated magnetic steel sheets is the largest at the axial end (A) and gradually decreases toward the central part in the axial direction ( A → E).

  However, in this case (FIG. 3), since there are many types of electromagnetic steel sheets to be punched, a large-scale mold and press equipment are required.

  On the other hand, for example, the stator core 10 of Modification 1 shown in FIG. 4 is formed by successively laminating a plurality of electromagnetic steel sheets having the same shape, and the circumferential length of the nonmagnetic space 2 with respect to the axial direction. It is changed in a staircase shape.

  Therefore, as shown in FIG. 5, there are five types of electromagnetic steel sheets A to E of the stator core 10 of the first modification.

  By doing in this way, the kind of electromagnetic steel plate for comprising the nonmagnetic space 2 can be reduced, and the scale of a metal mold | die and a press installation can be reduced.

  Moreover, you may comprise the nonmagnetic space 2 by the some slit hole 2b, 2c, 2d, 2e opened in an axial direction like the stator core 10 of the modification 2 shown in FIG. The slit holes 2b, 2c, 2d, and 2e are defined as “space”.

  The slit holes 2b, 2c, 2d, and 2e are formed in order from the vicinity of the center in the circumferential direction of the rotor facing portion 1a toward both ends in the circumferential direction. The length in the axial direction is the shortest in the slit hole 2b near the center, gradually increases toward both ends in the circumferential direction, and the slit hole 2e is longest.

  By configuring as shown in FIG. 6, an effect close to the nonmagnetic space 2 shown in FIG. 2 can be obtained.

  As shown in FIG. 7, the stator iron core 10 of Modification 2 shown in FIG. 6 has an electromagnetic steel plate in the vicinity of the position A in the axial direction with slit holes 2b, 2c, 2d, 2e left and right in the rotor facing portion 1a. It has almost symmetry.

  Further, the electromagnetic steel sheet near the position B in the axial direction has slit holes 2c, 2d, and 2e in the rotor facing portion 1a substantially symmetrically on the left and right.

  Further, the electromagnetic steel sheet near the position C in the axial direction has slit holes 2d and 2e in the rotor facing portion 1a substantially symmetrically on the left and right.

  The electromagnetic steel sheet near the position D in the axial direction has slit holes 2e in the rotor facing portion 1a approximately symmetrically on the left and right.

  Further, the electromagnetic steel sheet near the axial position E has no slit hole in the rotor facing portion 1a.

  Thus, since holes (slit holes) for punching out electromagnetic steel sheets to form the nonmagnetic space 2 can also be realized by changing the number thereof as shown in FIG. Can be manufactured.

  As shown in the present embodiment, when the nonmagnetic space 2 is provided inside the rotor facing portion 1a of the tooth portion 1 of the stator core 10, the external shape of the end portion in the axial direction of the rotor facing portion 1a is nonmagnetic. This is the same as in the case of the rotor facing portion 1a without the space 2. Therefore, it is not necessary to make the insulator made of resin used as insulation between the stator core 10 and the winding and as a winding frame for preventing the winding from falling to the rotor side to have a special shape. Further, the strength can be increased by fitting a part of the insulator into the nonmagnetic space 2.

  In addition, since no groove is formed in the inner peripheral surface (the surface facing the rotor) of the rotor facing portion 1a, the inner peripheral surface of the stator core 10 can be configured by an arc, and the management of dimensions is facilitated.

  Further, for example, when the synchronous motor including the stator core 10 of the present embodiment is used for a compressor in which the motor body is used in refrigerant or refrigeration oil, the gap between the rotor and the stator is a slot opening. Since the portions other than the portion 3a are uniform, the flow of the refrigerant and the refrigerating machine oil between the gaps due to the rotation of the rotor is less likely to be disturbed, and loss is less likely to occur.

  FIG. 8 shows an induced voltage waveform of the synchronous motor using the stator core 10 shown in FIG. For comparison, an induced voltage waveform of the synchronous motor using the stator core 10 having no nonmagnetic space 2 is also shown. As the rotor, a rotor having a permanent magnet disposed on the surface thereof was used. The permanent magnet was a cylindrical one, and a radially oriented magnet was magnetized in multiple poles. The number of slots is 6, and the number of poles is 4.

  Compared to the induced voltage when a stator having no nonmagnetic space 2 is used for the rotor facing portion 1a of the stator core 10, the induced voltage of the synchronous motor using the stator core 10 of FIG. It can be seen that the distortion is reduced.

  FIG. 10 shows the result of frequency analysis of the waveform of the induced voltage. The rotation angle 180 ° in FIG. 8 is defined as one period (basic frequency), and the degree to which an integer multiple frequency component is included is analyzed. The total distortion rate (THD) is obtained by taking the square root of the sum of the squares of the ratio of each frequency component to the fundamental frequency component. Some components are increasing (seventh component, eleventh component), but the fifth component, which is the largest component, is greatly decreased, and the total distortion (THD) as a whole is also decreased. It can be seen that the distortion of the induced voltage is reduced.

  FIG. 9 shows the cogging torque waveform of the synchronous motor using the stator core 10 shown in FIG. For comparison, the waveform of the cogging torque of the synchronous motor using the stator core 10 having no nonmagnetic space 2 is also shown. Since the shape of the slot opening 3a is the same, it can be seen that the cogging torque does not show an increasing tendency and is slightly reduced.

  As described above, the stator core 10 of the synchronous motor according to the present embodiment has the nonmagnetic spaces 2 at the four corners when viewed from the rotor inside the rotor facing portion 1a. The volume of the nonmagnetic space 2 gradually increases from the axially central portion of the rotor facing portion 1a toward both end portions in the axial direction, and is highest at both axial end portions and circumferential end portions of the rotor facing portion 1a. It becomes a big space. As a result, the shape of the region of the rotor facing portion 1a in which many magnetic bodies (magnetic steel plates) are present is substantially octagonal to hexagonal when viewed from the rotor. With this configuration, when the rotor rotates, the area where the rotor facing portion 1a of the stator core 10 faces the rotor magnetic pole is initially small, and the rotation proceeds toward the center of the tooth portion 1 as the rotor rotates. The amount of increase in area gradually increases. Therefore, the sudden flow of magnetic flux into the teeth is suppressed, distortion of the induced voltage generated in the winding is reduced, torque pulsation is suppressed, and a synchronous motor with less vibration and noise can be obtained.

  Moreover, the electromagnetic steel plate for comprising the nonmagnetic space 2 by laminating | stacking several electromagnetic steel plates of the same shape continuously, and changing the circumferential direction length of the nonmagnetic space 2 to step shape with respect to an axial direction. The size of molds and press facilities can be reduced.

  In addition, by configuring the nonmagnetic space 2 with a plurality of slit holes 2b, 2c, 2d, and 2e that can be opened in the axial direction, holes (slit holes) for punching out electromagnetic steel sheets to form the nonmagnetic space 2 are also provided. Since this can be realized by changing the number, it is possible to manufacture with a small-scale mold and press facility.

  In addition, since no groove is formed in the inner peripheral surface (the surface facing the rotor) of the rotor facing portion 1a, the inner peripheral surface of the stator core 10 can be configured by an arc, and the management of dimensions is facilitated.

  Further, for example, when the synchronous motor including the stator core 10 of the present embodiment is used for a compressor whose motor body is used in refrigerant or refrigeration oil, a gap between the rotor and the stator is present. Since the portions other than the slot opening 3a are uniform, the flow of the refrigerant and the refrigerating machine oil between the gaps due to the rotation of the rotor is less likely to occur, and loss is less likely to occur.

Embodiment 2. FIG.
FIGS. 11 to 13 are views showing the second embodiment, FIG. 11 is an enlarged perspective view of the tooth portion 1 of the stator core 10 of the synchronous motor, and FIG. 12 is the tooth portion 1 of the stator core 10 of the first modification. 13 is an enlarged perspective view, and FIG. 13 is an enlarged perspective view of the tooth portion 1 of the stator core 10 of the second modification.

  The configuration of the stator core 10 of the synchronous motor will be described with reference to FIG. Inside the rotor facing portion 1 a of the tooth portion 1 of the stator core 10, there are nonmagnetic spaces 2 at two corners (corners) as viewed from the rotor. These nonmagnetic spaces 2 are arranged diagonally.

  The circumferential length of the nonmagnetic space 2 is gradually increased from the central portion in the axial direction of the rotor facing portion 1a toward both end portions in the axial direction. Since the overall dimension of the nonmagnetic space 2 in the radial direction is substantially the same, the volume of the nonmagnetic space 2 gradually increases from the axially central portion of the rotor facing portion 1a toward both axial end portions. In other words, the volume of the nonmagnetic space 2 gradually increases from the circumferential center of the rotor facing portion 1a toward both circumferential ends. That is, the nonmagnetic space 2 is the largest space at both axial end portions and circumferential end portions of the rotor facing portion 1a.

  As a result, the shape of the region where the magnetic body (electromagnetic steel plate) in the rotor facing portion 1a is abundant is substantially hexagonal.

  When the rotor of the synchronous motor rotates, the area of the rotor facing portion 1a of the stator core 10 that faces the magnetic poles of the rotor is the same as that of the stator core 10 without the nonmagnetic space 2. It gradually increases in proportion to the angle.

  On the other hand, in the stator core 10 of the synchronous motor having the nonmagnetic space 2, in the region where there are many magnetic bodies (electromagnetic steel plates) opposed to the magnetic poles of the rotor at first with respect to the rotation angle of the rotor. The increase in area is small and the increase in area gradually increases.

  When there is no nonmagnetic space 2 in the rotor facing portion 1a of the stator core 10, the change in magnetic flux flowing from the rotor magnetic pole into the rotor facing portion 1a changes according to the magnetic flux distribution of the rotor magnetic pole.

  For example, in the case of a rotor magnetized in a radial orientation, the change in the magnetic flux between the magnetic poles is abrupt. Therefore, the change in the magnetic flux flowing into the rotor facing portion 1a of the stator core 10 is suddenly changed near the switching of the magnetic poles. Change.

  Further, in the case of a rotor in which a permanent magnet is disposed inside a magnetic body, the magnetic flux generated from the permanent magnet can be freely changed in direction at the magnetic body portion on the outer peripheral portion of the permanent magnet. As the rotor rotates, the magnetic flux suddenly concentrates on the rotor facing portion 1a at the same time as it faces the rotor facing portion 1a of the stator core 10, and therefore flows into the rotor facing portion 1a of the stator core 10. Magnetic flux fluctuates rapidly.

  As a result, the induced voltage generated in the stator windings is distorted, and the torque pulsation of the synchronous motor is increased, causing vibration and noise.

  The stator of the synchronous motor according to the present embodiment has a shape in which a region where the magnetic material (electromagnetic steel plate) of the rotor facing portion 1a is large is just skewed, so that the rotor rotates when the rotor rotates. The area where the facing portion 1a faces the rotor magnetic pole is initially small, and the amount of increase in the area gradually increases as the rotation proceeds toward the center of the tooth portion 1. Therefore, the sudden flow of magnetic flux into the tooth portion 1 is suppressed, distortion of the induced voltage generated in the winding is reduced, torque pulsation is suppressed, and a synchronous motor with less vibration and noise is obtained.

  In general, when the slot opening 3a between the adjacent rotor facing portions 1a of the stator core 10 is increased, a space in which the magnetic resistance on the outer side (stator core 10 side) viewed from the rotor is increased, The difference in magnetic resistance between the slot opening 3a and the rotor facing portion 1a of the stator core 10 increases, and the cogging torque increases.

  For example, in the rotor facing portion 1a of the stator core 10, when the axial end portion is made completely non-magnetic space, the substantial slot opening portion 3a becomes wide (the slot opening at the axial end portion). As described above, the effect of suppressing the distortion of the induced voltage is obtained, but the cogging torque is increased.

  On the other hand, in the case of the stator core 10 of the synchronous motor shown in the present embodiment, since the width (circumferential direction) of the slot opening 3a does not widen, an increase in cogging torque can be suppressed.

  Usually, the stator core 10 is often constructed by laminating electromagnetic steel plates, and the stator core 10 shown in FIG. 2 is a hole for punching out the electromagnetic steel plates for constituting the nonmagnetic space 2 in the rotor facing portion 1a. Can be realized by gradually changing the shape of each steel sheet to be laminated.

  However, in this case, since there are many types of electromagnetic steel sheets to be punched, a large-scale mold and press equipment are required.

  On the other hand, for example, the stator core 10 of the synchronous motor according to the modified example 1 shown in FIG. 12 is formed by successively laminating a plurality of electromagnetic steel plates having the same shape, and the circumferential length of the nonmagnetic space 2 is set in the axial direction. It is changed stepwise.

  By doing in this way, the kind of the electromagnetic steel plate (after punching) for comprising the nonmagnetic space 2 can be reduced, and the scale of a metal mold | die and a press installation can be reduced.

  Moreover, you may comprise the nonmagnetic space 2 by several slit hole 2b, 2c, 2d, 2e opened to an axial direction like the stator core 10 of the modification 2 shown in FIG. The slit holes 2b, 2c, 2d, and 2e are defined as “space”.

  The slit holes 2b, 2c, 2d, and 2e are formed in order from the vicinity of the central portion in the circumferential direction of the rotor facing portion 1a toward the circumferential end. The length in the axial direction is the shortest in the slit hole 2b near the center, gradually increases toward both ends in the circumferential direction, and the slit hole 2e is longest.

  By comprising in this way, the effect close | similar to the nonmagnetic space 2 shown in FIG. 11 is acquired. Further, since holes (slit holes) for punching out electromagnetic steel sheets to form the non-magnetic space 2 can be realized by changing the number thereof, it is possible to manufacture with a small-scale mold and press equipment.

  As shown in the present embodiment, when the nonmagnetic space 2 is provided inside the rotor facing portion 1a of the tooth portion 1 of the stator core 10, the external shape of the end portion in the axial direction of the rotor facing portion 1a is nonmagnetic. This is the same as in the case of the rotor facing portion 1a without the space 2. Therefore, it is not necessary to make the insulator made of resin used as insulation between the stator core 10 and the winding and as a winding frame for preventing the winding from falling to the rotor side to have a special shape. Further, the strength can be increased by fitting a part of the insulator into the nonmagnetic space 2.

  As described above, according to this embodiment, the nonmagnetic property is arranged diagonally at the two corners (corners) as viewed from the rotor inside the rotor facing portion 1a of the tooth portion 1 of the stator core 10. A space 2 is provided, and the volume of the nonmagnetic space 2 gradually increases from the axially central portion of the rotor facing portion 1a toward both axial end portions. By setting the nonmagnetic space 2 to be the largest space at both axial end portions and circumferential end portions of the rotor facing portion 1a, the region where the magnetic material (electromagnetic steel plate) of the rotor facing portion 1a is large is just right. Because the shape is skewed, when the rotor rotates, the area where the rotor facing portion 1a faces the rotor magnetic pole is initially small and gradually increases as the rotation proceeds toward the center of the tooth portion 1. Increase in area increases. Therefore, the sudden flow of magnetic flux into the tooth portion 1 is suppressed, distortion of the induced voltage generated in the winding is reduced, torque pulsation is suppressed, and a synchronous motor with less vibration and noise is obtained.

  Further, since the width (circumferential direction) of the slot opening 3a does not increase, an increase in cogging torque can be suppressed.

  Moreover, the electromagnetic steel plate for comprising the nonmagnetic space 2 by laminating | stacking several electromagnetic steel plates of the same shape continuously, and changing the circumferential direction length of the nonmagnetic space 2 to step shape with respect to an axial direction. The number of types (after punching) can be reduced, and the scale of molds and press facilities can be reduced.

  Further, the slit holes 2b, 2c, 2d, 2e are formed in order from the vicinity of the central portion in the circumferential direction of the rotor facing portion 1a toward the circumferential end, and the length in the axial direction is set to the slit hole 2b in the vicinity of the central portion. 11 is the shortest, gradually lengthens toward both ends in the circumferential direction, and the slit hole 2e becomes the longest, thereby obtaining an effect close to the nonmagnetic space 2 shown in FIG. Further, since holes (slit holes) for punching out electromagnetic steel sheets to form the non-magnetic space 2 can be realized by changing the number thereof, it is possible to manufacture with a small-scale mold and press equipment.

Embodiment 3 FIG.
FIGS. 14 to 16 are diagrams showing the third embodiment, FIG. 14 is an enlarged perspective view of the tooth portion 1 of the stator core 10 of the synchronous motor, and FIG. 15 is the tooth portion 1 of the stator core 10 of the first modification. 16 is an enlarged perspective view, and FIG. 16 is an enlarged perspective view of the tooth portion 1 of the stator core 10 of the second modification.

  The configuration of the stator core 10 of the synchronous motor will be described with reference to FIG. Inside the rotor facing portion 1a, there is a nonmagnetic space 2 near the center in the axial direction at both ends in the circumferential direction when viewed from the rotor. These nonmagnetic spaces 2 are arranged symmetrically in the circumferential direction in the rotor facing portion 1a.

  The nonmagnetic space 2 has a circumferential length that gradually decreases from the axial center to the axial end. Since the overall dimension of the nonmagnetic space 2 in the radial direction is substantially the same, the volume of the nonmagnetic space 2 gradually decreases from the axially central portion of the rotor facing portion 1a toward both axial end portions. In other words, the volume of the nonmagnetic space 2 gradually increases from the circumferential center of the rotor facing portion 1a toward both circumferential ends. That is, the nonmagnetic space 2 is the largest space at both axial end portions and circumferential end portions of the rotor facing portion 1a. As a result, the shape of the region of the rotor facing portion 1a in which many magnetic bodies (magnetic steel plates) are present is such that the substantially trapezoidal region is turned upside down and overlapped.

  When the rotor of the synchronous motor rotates, the area of the rotor facing portion 1a of the stator core 10 that faces the magnetic poles of the rotor is the same as that of the stator core 10 without the nonmagnetic space 2. It gradually increases in proportion to the angle.

  On the other hand, in the stator core 10 of the synchronous motor having the nonmagnetic space 2, in the region where there are many magnetic bodies (electromagnetic steel plates) opposed to the magnetic poles of the rotor at first with respect to the rotation angle of the rotor. The increase in area is small and the increase in area gradually increases.

  When there is no nonmagnetic space 2 in the rotor facing portion 1a of the stator core 10, the change in magnetic flux flowing from the rotor magnetic pole into the rotor facing portion 1a changes according to the magnetic flux distribution of the rotor magnetic pole.

  For example, in the case of a rotor magnetized in a radial orientation, the change in the magnetic flux between the magnetic poles is abrupt. Therefore, the change in the magnetic flux flowing into the rotor facing portion 1a of the stator core 10 is suddenly changed near the switching of the magnetic poles. Change.

  Further, in the case of a rotor in which a permanent magnet is arranged inside a magnetic body, the magnetic flux generated from the permanent magnet is freely changed in direction at the magnetic body portion on the outer periphery of the permanent magnet. As the rotor rotates, the magnetic flux suddenly concentrates on the rotor facing portion 1a at the same time as it faces the rotor facing portion 1a of the stator core 10, and therefore flows into the rotor facing portion 1a of the stator core 10. Magnetic flux fluctuates rapidly.

  As a result, the induced voltage generated in the stator windings is distorted, and the torque pulsation of the synchronous motor is increased, causing vibration and noise.

  In the stator of the synchronous motor according to the present embodiment, since the magnetic body of the rotor facing portion 1a is small at the circumferential end, the area where the rotor facing portion 1a faces the rotor magnetic pole when the rotor rotates. However, the amount of increase in the area gradually increases as the rotation proceeds toward the center of the tooth portion 1. Therefore, the sudden flow of magnetic flux into the tooth portion 1 is suppressed, distortion of the induced voltage generated in the winding is reduced, torque pulsation is suppressed, and a synchronous motor with less vibration and noise is obtained.

  In general, when the slot opening 3a between the adjacent rotor facing portions 1a of the stator core 10 is increased, a space in which the magnetic resistance on the outer side (stator core 10 side) viewed from the rotor is increased, The difference in magnetic resistance between the slot opening 3a and the rotor facing portion 1a of the stator core 10 increases, and the cogging torque increases.

  For example, in the rotor facing portion 1a of the stator core 10, when the axial end portion is made completely non-magnetic space, the substantial slot opening portion 3a becomes wide (the slot opening at the axial end portion). As described above, the effect of suppressing the distortion of the induced voltage is obtained, but the cogging torque is increased.

  On the other hand, in the case of the stator of the synchronous motor shown in the present embodiment, since the width (circumferential direction) of the slot opening 3a does not widen, an increase in cogging torque can be suppressed.

  Usually, the stator core 10 is often constructed by laminating electromagnetic steel plates, and the stator core 10 shown in FIG. 14 is a hole for punching out the electromagnetic steel plates for constituting the nonmagnetic space 2 in the rotor facing portion 1a. Can be realized by gradually changing the shape of each steel sheet to be laminated.

  However, in this case, since there are many types of electromagnetic steel sheets to be punched, a large-scale mold and press equipment are required.

  On the other hand, for example, the stator iron core 10 of the synchronous motor according to the first modification shown in FIG. 15 is formed by successively laminating a plurality of electromagnetic steel plates having the same shape, and setting the circumferential length of the nonmagnetic space 2 in the axial direction. It is changed stepwise.

  By doing in this way, the kind of electromagnetic steel plate for comprising the nonmagnetic space 2 can be reduced, and the scale of a metal mold | die and a press installation can be reduced.

  Further, like the stator core 10 of the synchronous motor according to the modified example 2 shown in FIG. 16, the nonmagnetic space 2 may be composed of a plurality of slit holes 2b, 2c, 2d, and 2e that can be opened in the axial direction. The slit holes 2b, 2c, 2d, and 2e are defined as “space”.

  The slit holes 2b, 2c, 2d, and 2e are formed in order from the vicinity of the center in the circumferential direction of the rotor facing portion 1a toward both ends in the circumferential direction. The length in the axial direction is the shortest in the slit hole 2b near the center, gradually increases toward both ends in the circumferential direction, and the slit hole 2e is longest.

  By comprising in this way, the effect close | similar to the nonmagnetic space 2 shown in FIG. 14 is acquired. Moreover, since holes (slit holes) for punching electromagnetic steel sheets to form a nonmagnetic space can also be realized by changing the number thereof, it is possible to manufacture with small-scale molds and press facilities.

  As shown in the present embodiment, when the nonmagnetic space 2 is provided in the vicinity of the center in the axial direction inside the rotor facing portion 1a of the stator core 10, at the axial end of the stator core 10 rotor facing portion 1a. Since a magnetic body (magnetic steel sheet) is present, the strength is increased, and deformation of the iron core can be prevented during manufacturing and transportation.

  Further, as shown in the present embodiment, when the nonmagnetic space 2 is provided inside the rotor facing portion 1a of the tooth portion 1 of the stator core 10, the external shape of the axial end portion of the rotor facing portion 1a is as follows. This is the same as in the case of the rotor facing portion 1a without the nonmagnetic space 2. Therefore, it is not necessary to make the insulator made of resin used as insulation between the stator core 10 and the winding and as a winding frame for preventing the winding from falling to the rotor side to have a special shape.

  As described above, according to this embodiment, inside the rotor facing portion 1a of the tooth portion 1 of the stator core 10, symmetrically arranged in the circumferential direction near the axial center at both ends in the circumferential direction as viewed from the rotor. The volume of the nonmagnetic space 2 is gradually reduced from the central portion in the axial direction of the rotor facing portion 1a toward both end portions in the axial direction. Since the nonmagnetic space 2 is the largest space at both axial end portions and circumferential end portions of the rotor facing portion 1a, the magnetic material of the rotor facing portion 1a is small at the circumferential end portion. When the rotor rotates, the area where the rotor facing portion 1a faces the rotor magnetic pole is initially small, and the amount of increase in the area gradually increases as the rotation proceeds toward the center of the tooth portion 1. Therefore, the sudden flow of magnetic flux into the tooth portion 1 is suppressed, distortion of the induced voltage generated in the winding is reduced, torque pulsation is suppressed, and a synchronous motor with less vibration and noise is obtained.

  Further, since the width (circumferential direction) of the slot opening 3a does not increase, an increase in cogging torque can be suppressed.

  Moreover, the electromagnetic steel plate for comprising the nonmagnetic space 2 by laminating | stacking several electromagnetic steel plates of the same shape continuously, and changing the circumferential direction length of the nonmagnetic space 2 to step shape with respect to an axial direction. The size of molds and press facilities can be reduced.

  The slit holes 2b, 2c, 2d, and 2e are formed in order from the vicinity of the central portion in the circumferential direction of the rotor facing portion 1a toward both ends in the circumferential direction, and the length in the axial direction is set to the slit hole 2b near the central portion. 14 is the shortest, gradually lengthens toward both ends in the circumferential direction, and the slit hole 2e becomes the longest, so that an effect close to that of the nonmagnetic space 2 shown in FIG. 14 can be obtained. Moreover, since holes (slit holes) for punching electromagnetic steel sheets to form a nonmagnetic space can also be realized by changing the number thereof, it is possible to manufacture with small-scale molds and press facilities.

  Further, when the nonmagnetic space 2 is provided in the vicinity of the center in the axial direction inside the rotor facing portion 1a of the stator core 10, a magnetic body (electromagnetic steel plate) is placed at the axial end of the stator core 10 rotor facing portion 1a. Since it exists, the strength is increased, and deformation of the iron core can be prevented during manufacturing and transportation.

  Further, when the nonmagnetic space 2 is provided inside the rotor facing portion 1 a of the tooth portion 1 of the stator core 10, the outer shape of the end portion in the axial direction of the rotor facing portion 1 a is the rotor facing without the nonmagnetic space 2. Since this is the same as in the case of the part 1a, an insulator made of resin is used as an insulation between the stator core 10 and the winding and as a winding frame for preventing the winding from falling to the rotor side. There is no need to make a special shape.

Embodiment 4 FIG.
FIGS. 17 to 19 are views showing the fourth embodiment, FIG. 17 is an enlarged perspective view of the tooth portion 1 of the stator core 10 of the synchronous motor, and FIG. 18 is the tooth portion 1 of the stator core 10 of the first modification. 19 is an enlarged perspective view, and FIG. 19 is an enlarged perspective view of the tooth portion 1 of the stator core 10 of the second modification.

  The configuration of the stator core 10 of the synchronous motor will be described with reference to FIG. Inside the rotor facing portion 1a, a non-magnetic space 2 having a substantially right triangle is formed at two corners as seen from the rotor. The two nonmagnetic spaces 2 are arranged symmetrically with respect to the substantially central portion of the rotor facing portion 1a. In this arrangement, the long sides of the two substantially right-angled triangles are substantially on the diagonal line of the rotor facing portion 1a.

  The nonmagnetic space 2 is largest at the axially central portion of the rotor facing portion 1a and gradually decreases toward the axial end portion. As a result, the shape of the region of the rotor facing portion 1a where a large amount of magnetic material (magnetic steel plate) is present is such that the rectangular notch is turned upside down and overlapped.

  When the rotor of the synchronous motor rotates, the area of the rotor facing portion 1a of the stator core 10 that faces the magnetic poles of the rotor is the same as that of the stator core 10 without the nonmagnetic space 2. It gradually increases in proportion to the angle.

  On the other hand, in the stator core 10 of the synchronous motor having the nonmagnetic space 2, the area of the region where a large amount of magnetic material opposed to the magnetic poles of the rotor initially exists is increased with respect to the rotation angle of the rotor. The area increases gradually and gradually.

  When there is no nonmagnetic space 2 in the rotor facing portion 1a of the stator core 10, the change in magnetic flux flowing from the rotor magnetic pole into the rotor facing portion 1a changes according to the magnetic flux distribution of the rotor magnetic pole.

  For example, in the case of a rotor magnetized in a radial orientation, the change in the magnetic flux between the magnetic poles is abrupt. Therefore, the change in the magnetic flux flowing into the rotor facing portion 1a of the stator core 10 is suddenly changed near the switching of the magnetic poles. Change.

  Further, in the case of a rotor in which a permanent magnet is arranged inside a magnetic body, the magnetic flux generated from the permanent magnet is freely changed in direction at the magnetic body portion on the outer periphery of the permanent magnet. As the rotor rotates, the magnetic flux suddenly concentrates on the rotor facing portion 1a at the same time as it faces the rotor facing portion 1a of the stator core 10, and therefore flows into the rotor facing portion 1a of the stator core 10. Magnetic flux fluctuates rapidly.

  As a result, the induced voltage generated in the stator windings is distorted, and the torque pulsation of the synchronous motor is increased, causing vibration and noise.

  The stator of the synchronous motor according to the present embodiment has a shape in which a region where the magnetic material (electromagnetic steel plate) of the rotor facing portion 1a is large is just skewed, so that the rotor rotates when the rotor rotates. The area where the facing portion 1a faces the rotor magnetic pole is initially small, and the amount of increase in the area gradually increases as the rotation proceeds toward the center of the tooth portion 1. Therefore, the sudden flow of magnetic flux into the tooth portion 1 is suppressed, distortion of the induced voltage generated in the winding is reduced, torque pulsation is suppressed, and a synchronous motor with less vibration and noise is obtained.

  In general, when the slot opening 3a between the adjacent rotor facing portions 1a of the stator core 10 is increased, a space in which the magnetic resistance on the outer side (stator core 10 side) viewed from the rotor is increased, The difference in magnetic resistance between the slot opening 3a and the rotor facing portion 1a of the stator core 10 increases, and the cogging torque increases.

  For example, in the rotor facing portion 1a of the stator core 10, when the axial end portion is made completely non-magnetic space, the substantial slot opening portion 3a becomes wide (the slot opening at the axial end portion). As described above, the effect of suppressing the distortion of the induced voltage is obtained, but the cogging torque is increased.

  On the other hand, in the case of the stator core 10 of the synchronous motor shown in the present embodiment, since the width of the slot opening 3a does not increase, an increase in cogging torque can be suppressed.

  Usually, the stator core 10 is often constructed by laminating electromagnetic steel plates, and the stator core 10 shown in FIG. 17 is a hole for punching out the electromagnetic steel plates for constituting the nonmagnetic space 2 in the rotor facing portion 1a. Can be realized by gradually changing the shape of each steel sheet to be laminated.

  However, in this case, since there are many types of electromagnetic steel sheets to be punched, a large-scale mold and press equipment are required.

  On the other hand, for example, the stator core 10 of the synchronous motor according to the first modification shown in FIG. 18 is formed by successively laminating a plurality of electromagnetic steel plates having the same shape, and the circumferential length of the nonmagnetic space 2 is set in the axial direction. It is changed stepwise.

  By doing in this way, the kind of electromagnetic steel plate for comprising the nonmagnetic space 2 can be reduced, and the scale of a metal mold | die and a press installation can be reduced.

  Moreover, you may comprise the nonmagnetic space 2 by the some slit hole 2b, 2c, 2d, 2e opened in an axial direction like the stator core 10 of the synchronous motor of the modification 2 shown in FIG. The slit holes 2b, 2c, 2d, and 2e are defined as “space”.

  The slit holes 2b, 2c, 2d, and 2e are formed in order from the vicinity of the central portion in the circumferential direction of the rotor facing portion 1a toward the circumferential end. The length in the axial direction is the shortest in the slit hole 2b near the center, gradually increases toward both ends in the circumferential direction, and the slit hole 2e is longest.

  By comprising in this way, the effect close | similar to the nonmagnetic space 2 shown in FIG. 17 is acquired. Further, since holes (slit holes) for punching out electromagnetic steel sheets to form the non-magnetic space 2 can be realized by changing the number thereof, it is possible to manufacture with a small-scale mold and press equipment.

  As shown in the present embodiment, a non-magnetic space inside the rotor facing portion 1a of the stator core 10 that is the largest at the axially central portion of the rotor facing portion 1a and gradually decreases toward the axial end. Since the magnetic substance is present at the end of the rotor facing portion 1a, the strength is increased, and deformation of the stator core 10 can be prevented during manufacturing and transportation.

  The appearance of the end portion in the axial direction of the rotor facing portion 1a is the same as that of the rotor facing portion 1a without the nonmagnetic space 2. Therefore, it is not necessary to make the insulator made of resin used as insulation between the stator core 10 and the winding and as a winding frame for preventing the winding from falling to the rotor side to have a special shape. Further, the strength can be increased by fitting a part of the insulator into the nonmagnetic space 2.

  As described above, according to this embodiment, since the region where the magnetic body (electromagnetic steel plate) of the rotor facing portion 1a of the stator core 10 is a lot is shaped like a skew, the rotor rotates. The area where the rotor facing portion 1a is opposed to the rotor magnetic pole is initially small, and the amount of increase in area gradually increases as the rotation proceeds toward the center of the tooth portion 1. Inflow of magnetic flux is suppressed, distortion of the induced voltage generated in the winding is reduced, torque pulsation is suppressed, and a synchronous motor with less vibration and noise is obtained.

  Further, since the width of the slot opening 3a does not increase, an increase in cogging torque can be suppressed.

  Moreover, the electromagnetic steel plate for comprising the nonmagnetic space 2 by laminating | stacking several electromagnetic steel plates of the same shape continuously, and changing the circumferential direction length of the nonmagnetic space 2 to step shape with respect to an axial direction. The size of molds and press facilities can be reduced.

  The slit holes 2b, 2c, 2d, and 2e are formed in order from the vicinity of the central portion in the circumferential direction of the rotor facing portion 1a toward both ends in the circumferential direction, and the length in the axial direction is set to the slit hole 2b near the central portion. 17 is the shortest, gradually lengthens toward both ends in the circumferential direction, and the slit hole 2e becomes the longest, whereby an effect close to the nonmagnetic space 2 shown in FIG. 17 can be obtained. Further, since holes (slit holes) for punching out electromagnetic steel sheets to form the non-magnetic space 2 can be realized by changing the number thereof, it is possible to manufacture with a small-scale mold and press equipment.

  Further, when a nonmagnetic space is provided inside the rotor facing portion 1a of the stator core 10 so as to be the largest at the axially central portion of the rotor facing portion 1a and gradually decrease toward the end in the axial direction, the rotor facing portion is provided. Since a magnetic substance is present at the end of the portion 1a, the strength is increased, and deformation of the stator core 10 can be prevented during manufacturing and transportation.

  Moreover, since the external appearance shape of the axial direction edge part of the rotor opposing part 1a becomes the same as that of the case of the rotor opposing part 1a without the nonmagnetic space 2, as an insulation between the stator core 10 and the winding, Further, it is not necessary to make the insulator made of a resin used as a winding frame that prevents the winding from falling to the rotor side into a special shape. Further, the strength can be increased by fitting a part of the insulator into the nonmagnetic space 2.

  As an application example of the present invention, application to a stator of a synchronous motor used in a compressor mounted on an air conditioner is possible.

FIG. 3 shows the first embodiment and is a perspective view of the stator core 10 of the synchronous motor. FIG. 3 is a diagram showing the first embodiment, and is an enlarged perspective view of a tooth portion 1 in FIG. 1. FIG. 2 shows the first embodiment, and is an enlarged perspective view (a) and a cross-sectional view (b) of A to E portions of the rotor facing portion 1a of the tooth portion 1 of FIG. FIG. 5 is a diagram showing the first embodiment, and is an enlarged perspective view of a tooth portion 1 of a stator core 10 of a first modification. FIG. 5 is a diagram showing the first embodiment, and is an enlarged perspective view of a rotor facing portion 1a in FIG. FIG. 5 is a diagram showing the first embodiment, and is an enlarged perspective view of a tooth portion 1 of a stator core 10 of a second modification. It is a figure which shows Embodiment 1, The perspective view (a) which expanded the rotor opposing part 1a of the tooth | gear part 1 of FIG. 6, and sectional drawing (b) of AE part. FIG. 5 is a diagram illustrating the first embodiment and is a diagram illustrating an induced voltage of the synchronous motor using the stator core 10 illustrated in FIG. 4. FIG. 3 shows the first embodiment and shows the cogging torque of the synchronous motor using the stator core 10. FIG. 3 is a diagram illustrating the first embodiment, and is a perspective view of a stator of a synchronous motor illustrating a result of frequency component analysis of an induced voltage. FIG. 5 is a diagram showing the second embodiment, and is an enlarged perspective view of a tooth portion 1 of a stator core 10 of a synchronous motor. FIG. 10 is a diagram showing the second embodiment, and is an enlarged perspective view of a tooth portion 1 of a stator core 10 of a first modification. FIG. 10 is a diagram showing the second embodiment, and is an enlarged perspective view of a tooth portion 1 of a stator core 10 of a second modification. FIG. 9 is a diagram showing the third embodiment, and is an enlarged perspective view of a tooth portion 1 of a stator core 10 of a synchronous motor. FIG. 10 is a diagram showing the third embodiment, and is an enlarged perspective view of a tooth portion 1 of a stator core 10 of a first modification. FIG. 9 is a diagram showing the third embodiment, and is an enlarged perspective view of a tooth portion 1 of a stator core 10 of a second modification. The perspective view which expanded Embodiment and is the figure which shows Embodiment 4 and the tooth | gear part 1 of the stator core 10 of a synchronous motor. FIG. 10 is a diagram showing the fourth embodiment, and is an enlarged perspective view of a tooth portion 1 of a stator core 10 of a first modification. FIG. 12 is a diagram showing the fourth embodiment, and is an enlarged perspective view of a tooth portion 1 of a stator core 10 of a second modification.

Explanation of symbols

  1 tooth part, 1a rotor facing part, 2 nonmagnetic space, 2a hole, 2b slit hole, 2c slit hole, 2d slit hole, 2e slit hole, 3 slot, 3a slot opening, 10 stator core.

Claims (9)

In a stator of a synchronous motor comprising a stator core formed by laminating electromagnetic steel sheets, and a winding wound around the stator core and energized with current,
The stator core is
A plurality of teeth protruding toward the rotor rotating inside the stator of the synchronous motor;
Forming a part of the tooth portion and facing the rotor, a rotor facing portion;
A stator for a synchronous motor, comprising a nonmagnetic space provided inside the rotor facing portion and having a volume gradually increasing from a circumferential central portion toward both circumferential end portions. 2. The stator of a synchronous motor according to claim 1, wherein the non-magnetic space has a volume that gradually increases from an axially central portion toward both axial end portions.
The stator of the synchronous motor according to claim 1.   3. The stator of a synchronous motor according to claim 2, wherein the nonmagnetic space is concentrated near both ends of the rotor-facing portion of the tooth portion at both ends in the axial direction.   The nonmagnetic space is concentrated on one side in the circumferential direction at both ends in the axial direction of the rotor-facing portion of the tooth portion, and the circumferential position where the nonmagnetic space is concentrated at both ends in the axial direction is different. The stator of a synchronous motor according to claim 2.   The stator of a synchronous motor according to claim 1, wherein the non-magnetic space has a volume that gradually increases from both axial end portions toward an axial central portion.   6. The stator of a synchronous motor according to claim 5, wherein the nonmagnetic space is concentrated near both ends of the rotor-facing portion of the tooth portion at an axially central portion.   The non-magnetic space is concentrated on one side in the circumferential direction from the axial center to the axial end of the rotor-facing portion of the tooth, and concentrated from the axial central to the axial end. The stator of the synchronous motor according to claim 5, wherein positions in the circumferential direction are different.   The stator of a synchronous motor according to any one of claims 2 to 7, wherein the nonmagnetic space is changed stepwise in the axial direction.   The stator of a synchronous motor according to any one of claims 2 to 7, wherein the nonmagnetic space is constituted by a plurality of spaces having different axial lengths.

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