JP5355435B2 - Permanent magnet type motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a permanent magnet motor that improves insulation between stacked layers of electromagnetic steel plates to reduce high-frequency eddy-current loss caused by the PWM carrier frequency of an inverter. <P>SOLUTION: The permanent magnet motor is driven by the inverter that controls the motor at variable speed by PWM control. The permanent magnet motor includes a rotor placed inside a stator. The stator has a stator core which is made by stacking the given number of electromagnetic steel plates of given shapes and has a plurality of teeth and slots arranged circumferentially, and a plurality of stator grooves which are arranged axially along the inner circumference of the teeth of the stator core and are constituted by shifting them by a prescribed phase between the electromagnetic steel plates. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a permanent magnet type motor.

  Generally, in a rotating electric machine, a cylindrical rotor is provided at the center, and a substantially cylindrical stator is provided on the outer peripheral side thereof. The stator has a plurality of teeth (tooth portions) projecting inward from the cylindrical core back, and the stator winding is inserted into a slot sandwiched between the teeth.

  In such a stator, the magnetic flux inside the stator changes due to the rotating magnetic field. At this time, it is known that an eddy current is generated on the tip surface of the tooth due to a change in magnetic flux, and a heat loss of electromagnetic energy occurs due to the Joule heat generated accordingly. The heat loss is called eddy current loss.

  In a rotating electrical machine, it is preferable to reduce eddy current loss as much as possible in order to obtain as large an output as possible from a device of a certain size. However, in a stator formed entirely of steel, eddy currents can flow freely in each direction, so that the eddy currents that are independently generated tend to merge with each other and become a large current. For this reason, in a stator that is integrally formed of steel, the eddy current loss may increase and an output may not be obtained.

  Therefore, a stator formed by laminating a plurality of steel plates in the axial direction has been proposed, and such a stator is described in Patent Documents 1 to 3 and the like. These stators are composed of a plurality of stacked steel plates at the tip end surfaces of the teeth, and the resistance changes at the boundary surfaces of such steel plates, so eddy currents generated at the tip end surfaces of the teeth are in the axial direction of the stator. It is difficult to flow, and eddy current loss can be reduced.

  However, in the stator in which a plurality of steel plates are laminated, the eddy current generated on the tip end surface of the teeth can flow freely in each steel plate, which is insufficient to further reduce the eddy current loss. In order to realize a small-sized and light-weight motor with high output, a stator that can further reduce eddy current loss at the tip end surface of the teeth is required.

  Therefore, in order to provide a stator that can reduce eddy current loss at the tip end surface of a tooth in a rotating electric machine, the stator is used in a rotating electric machine, and is formed by laminating a plurality of steel plates. A stator is proposed in which a plurality of grooves are formed along the stacking direction on the tip end surface of the teeth (see, for example, Patent Document 4).

  In the stator described in Patent Document 4, the eddy current generated on the teeth tip surface of the stator is difficult to flow in the direction in which the steel plates of the stator are laminated because the boundary surface of each steel plate becomes a resistance. Moreover, in the part provided with the groove in the same steel plate, it can only flow independently in a very narrow region partitioned by the groove. Therefore, eddy currents that are independently generated are unlikely to merge with each other at the tip end surfaces of the teeth, and a large current is not generated.

  In addition, an average gap length between the rotor and the stator is G, and a plurality of grooves are formed in the facing surface of the stator teeth facing the rotor along the stacking direction of the iron plates. Is larger than the average gap length G, the groove pitch R is 3 times or less of the iron plate thickness t, and the ratio (M / S) of the groove opening area M to the total area S on the facing surface is 50% or less. Thus, an automotive alternator that reduces eddy current loss and has excellent power generation efficiency has been proposed (see, for example, Patent Document 5).

  Also, by providing an uneven surface on the rotor outer peripheral surface of the rotor and an uneven surface on the stator tooth surface of the stator, the eddy current loss on the rotor outer peripheral surface is reduced by the uneven surface, and the stator There has been proposed a motor capable of reducing eddy current loss on the tooth surface by the uneven surface (see, for example, Patent Document 6).

JP 56-49661 A Japanese Patent Laid-Open No. 2-131339 Japanese Utility Model Publication No. 3-26272 JP-A-5-64383 Japanese Patent Laid-Open No. 5-184088 JP 2001-57746 A

  However, since the stators described in Patent Documents 4 to 6 are all separated by grooves formed along the stacking direction, sufficient insulation between the stacks cannot be obtained, and straddles the stacks. In particular, when an eddy current in the path is generated and the motor is controlled at a variable speed using an inverter, the PWM carrier frequency is multiplied by N (N is a component of the PWM carrier frequency) due to the PWM (Pulse Width Modulation) pulse frequency of the inverter. Eddy current loss of an integer of 1 or more occurred, and the motor efficiency was deteriorated.

  The present invention has been made in order to solve the above-described problems, and provides a permanent magnet type motor that can increase insulation between layers and reduce high-frequency eddy current loss caused by the PWM carrier frequency of the inverter. provide.

A permanent magnet type motor according to the present invention is driven by an inverter that performs variable speed control by PWM (Pulse Width Modulation) control, and a permanent magnet type motor in which a rotor is disposed inside a stator.
The stator is
A stator core having a plurality of teeth and slots along the circumferential direction, which is configured by laminating a predetermined number of electromagnetic steel sheets of a predetermined shape,
A plurality of pieces are formed in the axial direction along the inner peripheral portion of each tooth of the stator core, and the phase is shifted by a predetermined phase between the electromagnetic steel sheets.

  The rotor of the permanent magnet type motor according to the present invention reduces the high-frequency eddy current loss that depends on the PWM carrier frequency that occurs when the motor is controlled at a variable speed using an inverter, and provides a highly efficient permanent magnet type motor. realizable.

FIG. 3 shows the first embodiment, and is a transverse sectional view of a stator 100 of a permanent magnet type motor. The A section enlarged view of FIG. The B section enlarged view of FIG. The C section enlarged view of FIG. FIG. 5 shows the first embodiment, and is an enlarged view (transverse cross-sectional view) of the vicinity of the tip portion of the first tooth 11A. It is a figure which shows Embodiment 1, and is an enlarged view (transverse cross-sectional view) near the front-end | tip part of the 2nd teeth 11B. FIG. 5 shows the first embodiment, and is an enlarged view (transverse sectional view) in the vicinity of a tip portion of a third tooth 11C. FIG. 3 shows the first embodiment, and is a partial front view seen from the inner diameter side of the stator core 10. FIG. 9 is an enlarged view of a part of FIG. 8. FIG. 5 shows the first embodiment, and is a plan view of a first core sheet 10A that constitutes the stator core 110 of Modification 1. FIG. The A section enlarged view of FIG. FIG. 5 shows the first embodiment, and is a plan view of a second core sheet 10B that constitutes the stator core 110 of Modification 1. FIG. The B section enlarged view of FIG. FIG. 5 shows the first embodiment, and is a plan view of a third core sheet 10C that constitutes the stator core 110 of the first modification. The C section enlarged view of FIG. FIG. 9 shows the first embodiment, and is a partial front view as seen from the inner diameter side of the stator core 110 of the first modification. FIG. 17 is an enlarged view of a part of FIG. 16. FIG. 5 shows the first embodiment, and is a transverse cross-sectional view of a stator 200 of a second modification. The E section enlarged view of FIG. The F section enlarged view of FIG. FIG. 5 shows the first embodiment, and is an enlarged view (cross-sectional view) of the vicinity of the tip portion of the first tooth 211E. FIG. 5 shows the first embodiment, and is an enlarged view (transverse cross-sectional view) of the vicinity of a tip portion of a second tooth 211F. FIG. 5 shows the first embodiment, and is a partial front view as seen from the inner diameter side of a stator core 210 of a second modification. FIG. 5 shows the first embodiment, and is a plan view of a first core sheet 310E that constitutes the stator core 310 of Modification 3. FIG. The E section enlarged view of FIG. FIG. 9 shows the first embodiment, and is a plan view of a second core sheet 310F that constitutes the stator core 310 of the third modification. The F section enlarged view of FIG. FIG. 5 shows the first embodiment, and is a partial front view as seen from the inner diameter side of a stator core 310 of a third modification. FIG. 10 shows the first embodiment, and is a transverse cross-sectional view of a stator 400 of a fourth modification. The G section enlarged view of FIG. The H section enlarged view of FIG. The J section enlarged view of FIG. FIG. 10 shows the first embodiment, and is a transverse cross-sectional view of a stator 500 of a fifth modification. The K section enlarged view of FIG. The L section enlarged view of FIG. The M section enlarged view of FIG.

Embodiment 1 FIG.
FIG. 1 shows the first embodiment, and is a cross-sectional view of a stator 100 of a permanent magnet motor. A stator 100 shown in FIG. 1 includes a substantially cylindrical stator core 10 and windings (not shown) inserted into slots 12 of the stator core 10 via an insulating material (not shown). At least.

  The feature of the present embodiment is that there is a feature in the shape of the stator core 10, particularly the teeth (the first teeth 11A, the second teeth 11B, and the third teeth 11C (sometimes simply referred to as teeth). The stator core 10 will be mainly described.

  The cylindrical stator core 10 is configured by punching a thin electromagnetic steel sheet having a thickness of about 0.2 to 0.5 mm into a predetermined shape and laminating a predetermined number of sheets. The stator core 10 is formed by extending a plurality of first teeth 11A, second teeth 11B, and third teeth 11C radially inward from a cylindrical core back 13 on the outer peripheral portion. Three first teeth 11A, second teeth 11B, and third teeth 11C are sequentially formed in the clockwise direction, followed by another three first teeth 11A, second teeth 11B, and second teeth. Three teeth 11C are sequentially formed in the clockwise direction, and further three other first teeth 11A, second teeth 11B, and third teeth 11C are sequentially formed in the clockwise direction. The plurality of first teeth 11A, second teeth 11B, and third teeth 11C are formed at substantially equal intervals in the circumferential direction. Therefore, the stator core 10 includes a total of nine teeth: three first teeth 11A, three second teeth 11B, and three third teeth 11C.

  Between the teeth (that is, between the first teeth 11A and the second teeth 11B (three locations), between the second teeth 11B and the third teeth 11C (three locations), and between the third teeth 11C and the first teeth Slots 12 having the same shape are formed between the three teeth 11 A. The teeth (first tooth 11 A, second tooth 11 B, and third tooth 11 C) have a circumferential width D ( The plurality of first teeth 11A, second teeth 11B, and third teeth 11C are formed at substantially equal intervals in the circumferential direction, so that the slots 12 are formed on the outer diameter side from the inner diameter side. A winding (not shown) is inserted into this slot 12 via an insulating material (not shown), for example, a predetermined number of turns on the teeth. Formed by directly wrapping Is a concentrated winding of the three-phase Y-connection.

  A notch 13 a is formed on the outer peripheral surface of the core back 13. The notch 13a is formed on the radial extension line of the teeth (the first tooth 11A, the second tooth 11B, and the third tooth 11C) so as not to narrow the magnetic path of the core back 13. These notches 13a serve as passages for refrigerant and refrigerating machine oil, for example, when the permanent magnet type motor of the present embodiment is used in a hermetic compressor. In the example of FIG. 1, nine notches 13a are formed in the same number as the teeth (the first teeth 11A, the second teeth 11B, and the third teeth 11C).

  The first teeth 11A, the second teeth 11B, and the third teeth 11C have a plurality of first stator grooves 11A-1 and second ends extending in the axial direction at their tip portions (inner peripheral surfaces). A stator groove 11B-1 and a third stator groove 11C-1 are respectively formed. The first stator groove 11A-1, the second stator groove 11B-1, and the third stator groove 11C-1 have different phases with respect to the center line of each tooth.

  That is, as shown in FIG. 2 (enlarged view of part A in FIG. 1), the first teeth 11A are formed with a plurality of first stator grooves 11A-1 having a triangular cross section. Let P be the pitch (circumferential period) of the first stator groove 11A-1. In the first tooth 11A, the peak of the first stator groove 11A-1 and the center line of the first tooth 11A coincide.

  The pitch P (circumferential direction) of the first stator groove 11A-1 is configured to be equal to or less than the thickness of the electromagnetic steel plate (thickness of about 0.2 to 0.5 mm). Moreover, the depth W (refer FIG. 2) of the 1st stator groove | channel 11A-1 is comprised so that it may become more than the board thickness of an electromagnetic steel plate (thickness about 0.2-0.5 mm).

  Further, as shown in FIG. 3 (enlarged view of portion B in FIG. 1), a plurality of second stator grooves 11B-1 having a triangular cross section are formed in the second tooth 11B. Let P be the pitch (circumferential direction) of the second stator groove 11B-1. In the second tooth 11B, the peak closest to the second tooth 11B center line of the second stator groove 11B-1 and the second tooth 11B center line are shifted by P / 3 pitch.

  The pitch P (period in the circumferential direction) of the second stator groove 11B-1 is configured to be equal to or less than the thickness of the electromagnetic steel plate (thickness of about 0.2 to 0.5 mm). Moreover, the depth W (refer FIG. 3) of the 2nd stator groove | channel 11B-1 is comprised so that it may become more than the plate | board thickness of an electromagnetic steel plate (thickness about 0.2-0.5 mm).

  Further, as shown in FIG. 4 (enlarged view of part C in FIG. 1), the third tooth 11C is formed with a plurality of third stator grooves 11C-1 having a triangular cross section. Let P be the pitch (circumferential period) of the third stator groove 11C-1. In the third tooth 11C, the mountain closest to the third tooth 11C center line of the third stator groove 11C-1 and the third tooth 11C center line are shifted by 2P / 3 pitch.

  The pitch P (circumferential direction) of the third stator groove 11C-1 is configured to be equal to or less than the thickness of the electromagnetic steel plate (thickness of about 0.2 to 0.5 mm). Moreover, the depth W (refer FIG. 4) of the 3rd stator groove | channel 11C-1 is comprised so that it may become more than the board thickness of an electromagnetic steel plate (thickness about 0.2-0.5 mm).

  FIG. 5 is a diagram showing the first embodiment, and is an enlarged view (transverse sectional view) of the vicinity of the tip portion of the first tooth 11A. The tip portion of the first tooth 11A is divided by the radial center line of the first stator groove 11A-1, and the hatched portion in FIG. 5 is defined as a convex portion 11A-2. Further, a portion radially outside the radial center line of the first stator groove 11A-1 is defined as a recess 11A-3.

  FIG. 6 is a diagram showing the first embodiment, and is an enlarged view (transverse sectional view) of the vicinity of the tip of the second tooth 11B. The tip of the second tooth 11B is divided by the radial center line of the second stator groove 11B-1, and the hatched portion in FIG. Further, a portion radially outside the radial center line of the second stator groove 11B-1 is defined as a recess 11B-3.

  FIG. 7 is a diagram showing the first embodiment, and is an enlarged view (transverse sectional view) of the vicinity of the tip portion of the third tooth 11C. The tip portion of the third tooth 11C is divided by the radial center line of the third stator groove 11C-1, and the hatched portion in FIG. 7 is defined as a convex portion 11C-2. In addition, a portion radially outside the radial center line of the third stator groove 11C-1 is defined as a recess 11C-3.

  FIG. 8 shows the first embodiment, and is a partial front view as seen from the inner diameter side of the stator core 10. The stator core 10 is formed by laminating a predetermined number of electromagnetic steel sheets punched into a predetermined shape. In this embodiment, for example, as shown in FIG. 8, the electromagnetic steel sheet punched into a predetermined shape is formed. Each sheet is laminated while rotating by 1 teeth pitch (in this embodiment, since there are 9 teeth, 1 teeth pitch is 40 ° (mechanical angle)). In the example of FIG. 1, the layers are stacked while being rotated one teeth pitch counterclockwise.

  When the stator core 10 laminated in this way is viewed from the inside at the first tooth 11A portion of the electromagnetic steel sheet located at the top in FIG. 8, the structure is as shown in FIG.

  In FIG. 8, the hatched portions of the respective teeth (the first teeth 11A, the second teeth 11B, and the third teeth 11C) indicate the convex portions 11A-2, 11B-2, and 11C-2, respectively. Moreover, the part without hatching has each shown recessed part 11A-3, 11B-3, 11C-3.

  FIG. 9 is an enlarged view of a part of FIG. As shown in FIG. 9, the convex portion 11A-2 (one of the convex portions 11A-2) of the uppermost first tooth 11A and the next (lower) of the uppermost first tooth 11A. ) The protrusion 11B-2 closest to the protrusion 11A-2 of the first tooth 11A at the top of the second tooth 11B is shifted by P / 3 in the circumferential direction (clockwise, right side in FIG. 9). ing. Accordingly, the recess 11A-3 (one of the recesses 11A-3) of the uppermost first tooth 11A and the second (lower) second tooth 11B of the uppermost first tooth 11A. The recess 11B-3 closest to the recess 11A-3 of the uppermost first tooth 11A is shifted by P / 3 in the circumferential direction (clockwise, right side in FIG. 9).

  Moreover, as shown in FIG. 9, the convex part 11B-2 (one of convex part 11B-2) of the 2nd teeth 11B (lower) of the 1st teeth 11A of the uppermost part, The convex portion 11C-2 closest to the convex portion 11B-2 of the second tooth 11B of the second tooth 11C next (lower) of the second tooth 11B is the circumferential direction (clockwise, right side in FIG. 9) ) Is shifted by P / 3. Accordingly, the recess 11B-3 of the second tooth 11B (one of the recesses 11B-3) and the second tooth 11B of the third tooth 11C next (lower) of the second tooth 11B. The recess 11C-3 closest to the recess 11B-3 is shifted by P / 3 in the circumferential direction (clockwise, right side in FIG. 9).

  Further, as shown in FIG. 9, the convex portion 11C-2 (one of the convex portions 11C-2) of the third third tooth 11C from the top, and the fourth first tooth from the top. The convex portion 11A-2 of the fourth first tooth 11A from the top closest to the convex portion 11C-2 of the third tooth 11C third from the top of 11A is the circumferential direction (clockwise, in FIG. Right side) is shifted by P / 3. Accordingly, the concave portion 11C-3 of the third tooth 11C third from the top (one of the concave portions 11C-3) and the third third tooth from the top of the first tooth 11A fourth. The third tooth 11C of the third tooth 11C that is closest to the concave portion 11C-3 is shifted from the concave portion 11A-3 of the fourth first tooth 11A by P / 3 in the circumferential direction (clockwise, right side in FIG. 9). . The stator core 10 is laminated by repeating the above configuration.

  As shown in FIG. 9, between the convex portions of adjacent electromagnetic steel sheets (the convex portions 11A-2 and the convex portions 11B-2, the convex portions 11B-2 and the convex portions 11C-2, the convex portions 11C-2 and the convex portions 11A- In 2), the communication area is less than half compared to the case of one type of electromagnetic steel sheet. Therefore, the eddy current of the path | route over the convex part of an adjacent electromagnetic steel plate can be suppressed.

  Each electromagnetic steel sheet is insulated on both sides, but in the case of high-frequency eddy currents, eddy currents in the path between adjacent electromagnetic steel sheets flow even if the electromagnetic steel sheet is insulated. Tend. In particular, when variable speed control of a motor is performed using an inverter, a high-frequency vortex of an N-fold component (N is a natural number) of the PWM carrier frequency due to the PWM (Pulse Width Modulation) pulse frequency of the inverter. Current loss can be suppressed and a highly efficient permanent magnet motor can be realized.

  FIGS. 10 to 17 are views showing the first embodiment, FIG. 10 is a plan view of the first core sheet 10A constituting the stator core 110 of Modification 1, and FIG. 11 is an enlarged view of a portion A in FIG. 12 is a plan view of the second core sheet 10B constituting the stator core 110 of the first modification, FIG. 13 is an enlarged view of a portion B of FIG. 12, and FIG. 14 is a second view of the stator core 110 of the first modification. 15 is a plan view of the core sheet 10 </ b> C, FIG. 15 is an enlarged view of a portion C in FIG. 14, FIG. 16 is a partial front view as seen from the inner diameter side of the stator core 110 in the first modification, and FIG. It is an enlarged view.

  The stator core 10 shown in FIG. 1 has a configuration in which the shape of each core sheet is the same and the phase of the stator groove at the tip of adjacent teeth is shifted. For example, all the teeth are the first of FIG. The first core sheet 10A configured with the teeth 11A, the second core sheet 10B configured with all the teeth composed of the second teeth 11B of FIG. 1, and the third teeth 11C of FIG. You may make it laminate | stack in order the 3rd core sheet | seat 10C comprised by these.

  Hereinafter, the stator core 110 of Modification 1 having such a configuration will be described with reference to FIGS. 10 to 17. As shown in FIG. 10, all the teeth of the first core sheet 10 </ b> A constituting the stator core 110 of the first modification have the same configuration as the first teeth 11 </ b> A of FIG. 1.

  The first core sheet 10A is formed by punching a thin electromagnetic steel sheet having a thickness of about 0.2 to 0.5 mm into a predetermined shape. The first core sheet 10A is formed by extending a plurality (9 in FIG. 10) of first teeth 11A radially inward from an annular core back 13 on the outer peripheral portion.

  Between the first teeth 11A, the circumferential width D (see FIG. 10) is equal, and a plurality (9 in FIG. 10) of first teeth 11A are formed at substantially equal intervals in the circumferential direction. Therefore, the circumferential width of the slot 12 increases from the inner diameter side toward the outer diameter side. A winding (not shown) is inserted into the slot 12 via an insulating material (not shown). The winding is, for example, a three-phase Y-connection concentrated winding formed by directly winding a predetermined number of turns around a tooth.

  A notch 13 a is formed on the outer peripheral surface of the core back 13. The notch 13a is formed on an extension line in the radial direction of the first tooth 11A so as not to narrow the magnetic path of the core back 13. These notches 13a serve as passages for refrigerant and refrigerating machine oil, for example, when the permanent magnet type motor of the present embodiment is used in a hermetic compressor. In the example of FIG. 10, nine cutouts 13a are formed in the same number as the first teeth 11A.

  As shown in FIG. 11 (enlarged view of portion A in FIG. 10), a plurality of first stator grooves 11A-1 having a triangular cross section are formed in the first tooth 11A. Let P be the pitch (circumferential period) of the first stator groove 11A-1. In the first tooth 11A, the peak of the first stator groove 11A-1 and the center line of the first tooth 11A coincide.

  The pitch P (circumferential direction) of the first stator groove 11A-1 is configured to be equal to or less than the thickness of the electromagnetic steel plate (thickness of about 0.2 to 0.5 mm). Moreover, the depth W (refer FIG. 11) of the 1st stator groove | channel 11A-1 is comprised so that it may become more than the board thickness of an electromagnetic steel plate (thickness about 0.2-0.5 mm).

  As shown in FIG. 12, the second core sheet 10B constituting the stator core 110 of Modification 1 has the same configuration as that of the second tooth 11B of FIG.

  The second core sheet 10B is also formed by punching a thin electromagnetic steel sheet having a thickness of about 0.2 to 0.5 mm into a predetermined shape. The second core sheet 10B is also formed by extending a plurality (9 in FIG. 12) of second teeth 11B radially inward from the annular core back 13 on the outer peripheral portion.

  Since the circumferential width D (see FIG. 12) is equal between the second teeth 11B, and a plurality (9 in FIG. 12) of second teeth 11B are formed at substantially equal intervals in the circumferential direction. The slot 12 has a circumferential width that increases from the inner diameter side toward the outer diameter side. A winding (not shown) is inserted into the slot 12 via an insulating material (not shown). The winding is, for example, a three-phase Y-connection concentrated winding formed by directly winding a predetermined number of turns around a tooth.

  A notch 13 a is formed on the outer peripheral surface of the core back 13. The notch 13a is formed on the radial extension line of the second tooth 11B so as not to narrow the magnetic path of the core back 13. These notches 13a serve as passages for refrigerant and refrigerating machine oil, for example, when the permanent magnet type motor of the present embodiment is used in a hermetic compressor. In the example of FIG. 12, nine notches 13a are formed in the same number as the second teeth 11B.

  As shown in FIG. 13 (enlarged view of B portion in FIG. 12), the second teeth 11B are formed with a plurality of second stator grooves 11B-1 having a triangular cross section. Let P be the pitch (circumferential direction) of the second stator groove 11B-1. In the second tooth 11B, the peak closest to the second tooth 11B center line of the second stator groove 11B-1 and the second tooth 11B center line are shifted by P / 3 pitch.

  The pitch P (period in the circumferential direction) of the second stator groove 11B-1 is configured to be equal to or less than the thickness of the electromagnetic steel plate (thickness of about 0.2 to 0.5 mm). Moreover, the depth W (refer FIG. 13) of the 2nd stator groove | channel 11B-1 is comprised so that it may become more than the board thickness of an electromagnetic steel plate (thickness about 0.2-0.5 mm).

  As shown in FIG. 14, the third core sheet 10 </ b> C constituting the stator core 110 of Modification 1 has the same configuration as that of the third tooth 11 </ b> C of FIG. 1.

  The third core sheet 10C is also formed by punching a thin electromagnetic steel sheet having a thickness of about 0.2 to 0.5 mm into a predetermined shape. The third core sheet 10C is also formed by extending a plurality (nine in FIG. 14) of third teeth 11C radially inward from the annular core back 13 on the outer peripheral portion.

  Between the third core sheets 10C, the circumferential width D (see FIG. 14) is equal, and a plurality (9 in FIG. 14) of third teeth 11C are formed at substantially equal intervals in the circumferential direction. Therefore, the circumferential width of the slot 12 increases from the inner diameter side toward the outer diameter side. A winding (not shown) is inserted into the slot 12 via an insulating material (not shown). The winding is, for example, a three-phase Y-connection concentrated winding formed by directly winding a predetermined number of turns around a tooth.

  A notch 13 a is formed on the outer peripheral surface of the core back 13. The notch 13a is formed on an extension line in the radial direction of the first tooth 11A so as not to narrow the magnetic path of the core back 13. These notches 13a serve as passages for refrigerant and refrigerating machine oil, for example, when the permanent magnet type motor of the present embodiment is used in a hermetic compressor. In the example of FIG. 14, nine notches 13a are formed in the same number as the third teeth 11C.

  As shown in FIG. 15 (enlarged view of part C in FIG. 14), a plurality of third stator grooves 11C-1 having a triangular cross section are formed in the third tooth 11C. Let P be the pitch (circumferential period) of the third stator groove 11C-1. In the third stator groove 11C-1, the peak closest to the third tooth 11C center line of the third stator groove 11C-1 and the third tooth 11C center line are shifted by P / 3 pitch. Yes.

  The pitch P (circumferential direction) of the third stator groove 11C-1 is configured to be equal to or less than the thickness of the electromagnetic steel plate (thickness of about 0.2 to 0.5 mm). Moreover, the depth W (refer FIG. 15) of the 3rd teeth 11C is comprised so that it may become more than the board thickness of an electromagnetic steel plate (thickness about 0.2-0.5 mm).

  For example, as shown in FIG. 16, the stator core 110 according to the first modification includes a first core sheet 10A, a second core sheet 10B, a third core sheet 10C, a first core sheet 10A,.・ As shown in the figure, they are stacked in order. However, the core sheet disposed at the top may be any of the first core sheet 10A, the second core sheet 10B, and the third core sheet 10C. In that case, the order of the first core sheet 10A, the second core sheet 10B, and the third core sheet 10C is not changed. For example, when the core sheet disposed at the top is the second core sheet 10B, the second core sheet 10B, the third core sheet 10C, the first core sheet 10A, the second core sheet 10B Laminate in order. Further, when the core sheet to be arranged at the top is the third core sheet 10C, the third core sheet 10C, the first core sheet 10A, the second core sheet 10B, the third core sheet 10C from the top, -Laminate in order.

  Moreover, as shown in FIG. 17 (an enlarged view of a part of FIG. 16), the convex portion 11A-2 (one of the convex portions 11A-2) of the uppermost first core sheet 10A, The convex portion 11B-2 closest to the convex portion 11A-2 of the uppermost first core sheet 10A of the uppermost first core sheet 10B next to the (lower) second core sheet 10B is the circumference. The direction is shifted by P / 3 in the clockwise direction (right side in FIG. 17). Accordingly, the concave portion 11A-3 (one of the concave portions 11A-3) of the uppermost first core sheet 10A and the second (lower) second of the uppermost first core sheet 10A. The recess 11B-3 closest to the recess 11A-3 of the uppermost first core sheet 10A of the core sheet 10B is displaced by P / 3 in the circumferential direction (clockwise, right side in FIG. 17).

  In addition, as shown in FIG. 17, the convex portion 11B-2 (one of the convex portions 11B-2) of the second core sheet 10B next to (below) the uppermost first core sheet 10A. And the convex portion 11C-2 closest to the convex portion 11B-2 of the second core sheet 10B of the second core sheet 10B (lower) of the second core sheet 10B is the circumferential direction (clockwise) The right side in FIG. 9 is shifted by P / 3. Accordingly, the second core sheet 10B has a recess 11B-3 (one of the recesses 11B-3) and the second (lower) second core sheet 10C second of the second core sheet 10B. The recess 11C-3 closest to the recess 11B-3 of the core sheet 10B is displaced by P / 3 in the circumferential direction (clockwise, right side in FIG. 17).

  Moreover, as shown in FIG. 17, the convex part 11C-2 (one of the convex parts 11C-2) of the third core sheet 10C third from the top and the fourth first from the top The convex portion 11A-2 of the fourth core sheet 10A from the top closest to the convex portion 11C-2 of the third core sheet 10C third from the top of the core sheet 10A is the circumferential direction (clockwise) The right side in FIG. 9 is shifted by P / 3. Accordingly, the concave portion 11C-3 (one of the concave portions 11C-3) of the third core sheet 10C third from the top, and the third top from the top of the first core sheet 10A fourth from the top. Of the third core sheet 10C of the third core sheet 10C closest to the recess 11C-3 is the fourth recess from the top 11A-3 of the first core sheet 10A in the circumferential direction (clockwise, right side in FIG. 9) P / 3. It is only shifted. The stator core 10 is laminated by repeating the above configuration.

  As shown in FIG. 17, between the convex portions of adjacent core sheets (magnetic steel plates) (the convex portions 11A-2 and the convex portions 11B-2, the convex portions 11B-2 and the convex portions 11C-2, and the convex portions 11C-2) Although the convex portion 11A-2) is in communication, the communication area is less than half compared to the case where there is only one type of electromagnetic steel sheet. Therefore, the eddy current of the path | route over the convex part of an adjacent electromagnetic steel plate can be suppressed. In particular, when variable speed control of a motor is performed using an inverter, high-frequency eddy current loss of an N-fold component (N is a natural number) of the PWM carrier frequency is suppressed due to the PWM carrier frequency of the inverter, and high efficiency is achieved. The original effect which can implement | achieve a permanent magnet type motor is also show | played.

  In addition, since the stator core 110 of the first modification has no directionality in each core sheet (first core sheet 10A, second core sheet 10B, and third core sheet 10C), the configuration of the apparatus to be laminated is There is an effect that it becomes easy.

  18 to 23 are diagrams showing the first embodiment. FIG. 18 is a cross-sectional view of the stator 200 according to the second modification, FIG. 19 is an enlarged view of an E portion of FIG. 18, and FIG. FIG. 21, FIG. 21 is an enlarged view (cross-sectional view) of the vicinity of the tip portion of the first tooth 211E, FIG. 22 is an enlarged view (cross-sectional view) of the vicinity of the tip portion of the second tooth 211F, and FIG. It is the partial front view seen from the inner diameter side of the stator core 210.

  A stator 200 according to Modification 2 will be described with reference to FIGS. 18 to 23. A stator 200 shown in FIG. 18 includes a substantially cylindrical stator core 210 and windings (not shown) inserted into slots 212 of the stator core 210 via an insulating material (not shown). At least.

  A feature of the present embodiment is that there is a feature in the shape of the stator core 210, particularly the teeth (the first teeth 211E and the second teeth 211F (sometimes simply referred to as teeth)). Will be described.

  The cylindrical stator core 210 is formed by punching a thin electromagnetic steel sheet having a thickness of about 0.2 to 0.5 mm into a predetermined shape and laminating a predetermined number of sheets. The stator core 210 is formed by extending a plurality of first teeth 211E and second teeth 211F radially inward from a cylindrical core back 213 on the outer peripheral portion. Two first teeth 211E and second teeth 211F are sequentially formed in the clockwise direction, and then another two first teeth 211E and second teeth 211F are sequentially formed in the clockwise direction. Subsequently, another two first teeth 211E and second teeth 211F are sequentially formed in the clockwise direction. The plurality of first teeth 211E and second teeth 211F are formed at substantially equal intervals in the circumferential direction. Therefore, the stator core 10 includes a total of six teeth: three first teeth 211E and three second teeth 211F.

  Slots 212 having the same shape are formed between the teeth (ie, between the first tooth 211E and the second tooth 211F (six locations). The teeth (first tooth 211E, second tooth 211F). The circumferential width D1 (see FIG. 18) is equal, and the plurality of first teeth 211E and second teeth 211F are formed at substantially equal intervals in the circumferential direction. The width in the circumferential direction increases toward the radial side, and a winding (not shown) is inserted into the slot 212 via an insulating material (not shown). Is a concentrated winding of three-phase Y connection formed by directly winding the number of turns.

  A notch 213 a is formed on the outer peripheral surface of the core back 213. The notch 213a is formed on the radial extension line of the teeth (the first teeth 211E and the second teeth 211F) so as not to narrow the magnetic path of the core back 213. These notches 213a serve as passages for refrigerant and refrigerating machine oil, for example, when the permanent magnet type motor of the present embodiment is used in a hermetic compressor. In the example of FIG. 18, the same number of six notches 213a as the teeth (the first teeth 211E and the second teeth 211F) are formed.

  The first teeth 211E and the second teeth 211F are provided with a plurality of first stator grooves 211E-1 and second stator grooves 211F-1 extending in the axial direction at their tip portions (inner peripheral surfaces). Are formed respectively. And the phase with respect to the centerline of each teeth of the 1st stator groove | channel 211E-1 and the 2nd stator groove | channel 211F-1 is different, It is characterized by the above-mentioned.

  That is, as shown in FIG. 19 (enlarged view of portion E in FIG. 18), a plurality of first stator grooves 211E-1 having a triangular cross section are formed in the first tooth 211E. Let P be the pitch (period in the circumferential direction) of the first stator groove 211E-1. As for the 1st teeth 211E, the peak of the 1st stator slot 211E-1 and the 1st teeth 211E center line correspond.

  The pitch P (circumferential period) of the first stator groove 211E-1 is configured to be equal to or less than the thickness of the electromagnetic steel plate (thickness of about 0.2 to 0.5 mm). Moreover, the depth W (refer FIG. 19) of the 1st stator groove | channel 11A-1 is comprised so that it may become more than the board thickness of an electromagnetic steel plate (thickness about 0.2-0.5 mm).

  Further, as shown in FIG. 20 (enlarged view of portion F in FIG. 18), the second teeth 211F are formed with a plurality of second stator grooves 11F-1 having a triangular cross section. Let P be the pitch (cycle in the circumferential direction) of the second stator groove 211F-1. In the second tooth 211F, the peak closest to the second tooth 211F center line of the second stator groove 211F-1 and the second tooth 211F center line are shifted by P / 2 pitch.

  The pitch P (circumferential direction) of the second stator groove 211F-1 is configured to be equal to or less than the thickness of the electromagnetic steel plate (thickness of about 0.2 to 0.5 mm). Moreover, the depth W (refer FIG. 20) of the 2nd stator groove | channel 211F-1 is comprised so that it may become more than the plate | board thickness of an electromagnetic steel plate (thickness about 0.2-0.5 mm).

  In FIG. 21 (enlarged view (transverse cross-sectional view) near the tip of the first tooth 211E, the tip of the first tooth 211E is divided by the radial center line of the first stator groove 211E-1. A portion indicated by hatching in FIG. 21 is referred to as a convex portion 211E-2. Further, a portion radially outside the radial center line of the first stator groove 211E-1 is defined as a recess 211E-3.

  In FIG. 22 (enlarged view (cross-sectional view) near the tip of the second stator groove 211F-1), the tip of the second tooth 211F is the center in the radial direction of the second stator groove 211F-1. A portion indicated by hatching in FIG. Further, a portion radially outside the radial center line of the second stator groove 211F-1 is defined as a recess 211F-3.

  In FIG. 23 (partial front view seen from the inner diameter side of the stator core 210), the stator core 210 is formed by laminating a predetermined number of electromagnetic steel sheets punched into a predetermined shape. For example, as shown in FIG. 23, one tooth pitch (each stator steel core 210 has six teeth, each having a tooth pitch of 60 ° (machine It is a corner))) Laminate while rotating. In the example of FIG. 18, the layers are stacked while being rotated one teeth pitch counterclockwise.

  When the stator core 210 laminated in such a manner is viewed from the inside at the first tooth 211E portion of the electromagnetic steel sheet located at the uppermost position in FIG. 23, the structure shown in FIG. 23 is obtained.

  In FIG. 23, hatched portions of the respective teeth (first tooth 211E and second tooth 211F) indicate convex portions 211E-2 and 211F-2, respectively. Moreover, the part without hatching has shown recessed part 211E-3, 211F-3, respectively.

  As shown in FIG. 23, the convex portion 211E-2 of the uppermost first tooth 211E and the convex portion 211F-2 of the second (second) second tooth 211F next to the uppermost first tooth 211E are as follows. , Shifted by P / 2 in the circumferential direction (clockwise, right side in FIG. 23). Accordingly, the recess 211E-3 of the uppermost first tooth 211E and the recess 211F-3 of the (lower) second tooth 211F next to the uppermost first tooth 211E are in the circumferential direction (clockwise). The right side in FIG. 23 is shifted by P / 2. The stator core 10 is laminated by repeating the above configuration.

  As shown in FIG. 23, the convex portions (the convex portions 211E-2 and the convex portions 211F-2) of adjacent core sheets (magnetic steel plates) do not communicate with each other. Therefore, the eddy current of the path | route over the convex part of an adjacent electromagnetic steel plate can be suppressed.

  Each electromagnetic steel sheet is insulated on both sides, but in the case of high-frequency eddy currents, eddy currents in the path between adjacent electromagnetic steel sheets flow even if the electromagnetic steel sheet is insulated. Tend. In particular, when variable speed control of a motor is performed using an inverter, a high-frequency vortex of an N-fold component (N is a natural number) of the PWM carrier frequency due to the PWM (Pulse Width Modulation) pulse frequency of the inverter. Current loss can be suppressed and a highly efficient permanent magnet motor can be realized.

  FIGS. 24 to 28 are views showing the first embodiment, FIG. 24 is a plan view of a first core sheet 310E constituting the stator core 310 of the third modification, and FIG. 25 is an enlarged view of a portion E in FIG. 26 is a plan view of the second core sheet 310F constituting the stator core 310 of the third modification, FIG. 27 is an enlarged view of a portion F of FIG. 26, and FIG. 28 is an inner diameter side of the stator core 310 of the third modification. FIG.

  The stator core 210 shown in FIG. 18 has a configuration in which the core sheets have the same shape and the phases of the stator grooves at the tips of adjacent teeth are shifted. For example, all the teeth are formed in the first core shown in FIG. You may make it laminate | stack in order the 1st core sheet | seat 310E comprised by the teeth 211E, and the 2nd core sheet | seat 310F comprised by the 2nd teeth 211F of FIG.

  Hereinafter, the stator core 310 of Modification 3 having such a configuration will be described with reference to FIGS. 24 to 28. As shown in FIG. 24, all the teeth of the first core sheet 310E constituting the stator core 310 of Modification 3 have the same configuration as that of the first tooth 211E in FIG.

  The first core sheet 310E is formed by punching a thin electromagnetic steel sheet having a thickness of about 0.2 to 0.5 mm into a predetermined shape. The first core sheet 310E is formed by extending a plurality (six in FIG. 24) of first teeth 311E radially inward from an annular core back 313 at the outer peripheral portion.

  Between the first teeth 311E, the circumferential width D1 (see FIG. 24) is equal, and a plurality (six in FIG. 24) of first teeth 311E are formed at substantially equal intervals in the circumferential direction. Therefore, the circumferential width of the slot 312 increases from the inner diameter side toward the outer diameter side. A winding (not shown) is inserted into the slot 312 via an insulating material (not shown). The winding is, for example, a three-phase Y-connection concentrated winding formed by directly winding a predetermined number of turns around a tooth.

  A notch 313 a is formed on the outer peripheral surface of the core back 313. The notch 313a is formed on the radial extension line of the first tooth 311E so as not to narrow the magnetic path of the core back 313. These notches 313a serve as passages for refrigerant and refrigerating machine oil, for example, when the permanent magnet type motor of the present embodiment is used in a hermetic compressor. In the example of FIG. 24, the same number of six notches 313a as the first teeth 311E are formed.

  As shown in FIG. 25 (enlarged view of portion E in FIG. 24), the first teeth 311E are formed with a plurality of first stator grooves 311E-1 having a triangular cross section. Let P be the pitch (circumferential direction) of the first stator grooves 311E-1. In the first tooth 311E, the peak of the first stator groove 311E-1 and the center line of the first tooth 311E coincide.

  The pitch P (circumferential direction) of the first stator grooves 311E-1 is configured to be equal to or less than the thickness of the electromagnetic steel plate (thickness of about 0.2 to 0.5 mm). Moreover, the depth W (refer FIG. 25) of the 1st stator groove | channel 311E-1 is comprised so that it may become more than the plate | board thickness of an electromagnetic steel plate (thickness about 0.2-0.5 mm).

  As shown in FIG. 26, the second core sheet 310F constituting the stator core 310 of Modification 3 has the same configuration as that of the second tooth 311F of FIG.

  The second core sheet 310F is also formed by punching a thin electromagnetic steel sheet having a thickness of about 0.2 to 0.5 mm into a predetermined shape. The second core sheet 310F is also formed by extending a plurality (six in FIG. 26) of second teeth 311F radially inward from the annular core back 313 on the outer peripheral portion.

  Since the circumferential width D1 (see FIG. 26) is equal between the second teeth 311F, and a plurality (six in FIG. 26) of the second teeth 311F are formed at substantially equal intervals in the circumferential direction. The slot 312 has a circumferential width that increases from the inner diameter side toward the outer diameter side. A winding (not shown) is inserted into the slot 312 via an insulating material (not shown). The winding is, for example, a three-phase Y-connection concentrated winding formed by directly winding a predetermined number of turns around a tooth.

  A notch 313 a is formed on the outer peripheral surface of the core back 313. The notch 313a is formed on an extension line in the radial direction of the second tooth 311F so as not to narrow the magnetic path of the core back 313. These notches 313a serve as passages for refrigerant and refrigerating machine oil, for example, when the permanent magnet type motor of the present embodiment is used in a hermetic compressor. In the example of FIG. 26, the same number of six notches 313a as the second teeth 311F are formed.

  As shown in FIG. 27 (the F section enlarged view of FIG. 26), the second teeth 311F are formed with a plurality of second stator grooves 311F-1 having a triangular cross section. The pitch (period in the circumferential direction) of the second stator groove 311F-1 is P. In the second tooth 311F, the peak closest to the second tooth 311F center line of the second stator groove 311F-1 and the second tooth 311F center line are shifted by P / 2 pitch.

  The pitch P (circumferential period) of the second stator groove 311F-1 is configured to be equal to or less than the thickness of the electromagnetic steel plate (thickness of about 0.2 to 0.5 mm). Moreover, the depth W (refer FIG. 27) of the 2nd stator groove | channel 311F-1 is comprised so that it may become more than the board thickness of an electromagnetic steel plate (thickness about 0.2-0.5 mm).

  For example, as shown in FIG. 28, the stator core 310 according to the third modification includes a first core sheet 310E, a second core sheet 310F, a first core sheet 310E, a second core sheet 310F,.・ As shown in the figure, they are stacked in order. However, the core sheet disposed at the top may be either the first core sheet 310E or the second core sheet 310F.

  As shown in FIG. 28, communication between the convex portions (the convex portions 311E-2 and the convex portions 311F-2) of the adjacent core sheet (magnetic steel plate) is not performed. Therefore, the eddy current of the path | route over the convex part of an adjacent electromagnetic steel plate can be suppressed. In particular, when variable speed control of a motor is performed using an inverter, high-frequency eddy current loss of an N-fold component (N is a natural number) of the PWM carrier frequency is suppressed due to the PWM carrier frequency of the inverter, and high efficiency is achieved. The original effect which can implement | achieve a permanent magnet type motor is also show | played.

  Moreover, since the stator core 310 of the modification 3 does not have directionality in each core sheet (the first core sheet 310E and the second core sheet 310F), there is an effect that the configuration of the laminating apparatus becomes simple. .

  29 to 32 are diagrams showing the first embodiment. FIG. 29 is a cross-sectional view of the stator 400 according to the modified example 4. FIG. 30 is an enlarged view of a portion G in FIG. 32 is an enlarged view of a portion J in FIG.

  In the stator core 10 described above, the stator core 110 of the first modification, the stator core 210 of the second modification, and the stator core 310 of the third modification, the stator groove at the tip of the teeth is a single tooth. In FIG. 5, all the stator grooves have the same shape. The stator 400 of the modification 4 is such that the depth of the stator groove at the tip end portion of the tooth becomes larger as it becomes the circumferential end portion of the tip end portion of the tooth. With this configuration, the distortion of the induced voltage can be reduced, and in addition to the effect of reducing the eddy current, the iron loss can be suppressed by the induced voltage distortion and the noise can be reduced by reducing the torque ripple.

  A stator 400 according to Modification 4 will be described with reference to FIGS. The cylindrical stator core 410 is configured by punching a thin electromagnetic steel sheet having a thickness of about 0.2 to 0.5 mm into a predetermined shape and laminating a predetermined number of sheets. The stator core 410 is formed by extending a plurality of first teeth 411A, second teeth 411B, and third teeth 411C radially inward from a cylindrical core back 413 on the outer peripheral portion. Three first teeth 411A, a second tooth 411B, and a third tooth 411C are sequentially formed in the clockwise direction, followed by another three first teeth 411A, a second tooth 411B, and a second tooth. Three teeth 411C are sequentially formed in the clockwise direction, and further three other first teeth 411A, second teeth 411B, and third teeth 411C are sequentially formed in the clockwise direction. The plurality of first teeth 411A, second teeth 411B, and third teeth 411C are formed at substantially equal intervals in the circumferential direction. Therefore, the stator iron core 410 includes nine teeth, that is, three first teeth 411A, three second teeth 411B, and three third teeth 411C.

  Between the teeth (that is, between the first teeth 411A and the second teeth 411B (three places), between the second teeth 411B and the third teeth 411C (three places), and between the third teeth 411C and the first teeth Slots 412 having the same shape are formed between the three teeth 411A (three locations) The teeth (first tooth 411A, second tooth 411B, and third tooth 411C) have a circumferential width D ( 29) are equal, and the plurality of first teeth 411A, second teeth 411B, and third teeth 411C are formed at substantially equal intervals in the circumferential direction, so that the slot 412 extends from the inner diameter side to the outer diameter side. A winding (not shown) is inserted into the slot 412 via an insulating material (not shown), for example, at the teeth. Is a concentrated winding of the three-phase Y-connection which is formed by winding a number of turns directly.

  A notch 413 a is formed on the outer peripheral surface of the core back 413. The notch 413a is formed on a radial extension line of the teeth (first tooth 411A, second tooth 411B, and third tooth 411C) so as not to narrow the magnetic path of the core back 413. These notches 413a serve as passages for refrigerant and refrigeration oil when the permanent magnet motor of the present embodiment is used in a hermetic compressor, for example. In the example of FIG. 29, nine notches 413a are formed in the same number as the teeth (first teeth 411A, second teeth 411B, and third teeth 411C).

  The first teeth 411A, the second teeth 411B, and the third teeth 411C have a plurality of first stator grooves 411A-1 extending in the axial direction at their distal ends (inner peripheral surfaces), the second teeth 411A, and the second teeth 411C. A stator groove 411B-1 and a third stator groove 411C-1 are respectively formed. The first stator groove 411A-1, the second stator groove 411B-1, and the third stator groove 411C-1 have different phases with respect to the center line of each tooth.

  The phase of the first stator groove 411A-1, the second stator groove 411B-1, and the third stator groove 411C-1 with respect to the center line of each tooth is the same as that of the stator core 10. Since there is, explanation is omitted.

  The stator core 410 according to the modified example 4 further includes a stator groove (first stator groove) formed at the tip of each tooth (first tooth 411A, second tooth 411B, and third tooth 411C). 411A-1, the second stator groove 411B-1, and the third stator groove 411C-1) are characterized in that the depth becomes larger as they become the circumferential ends of the tips of the teeth.

  FIG. 30 (an enlarged view of a portion G in FIG. 29) illustrates the first stator groove 411A− using the first tooth 411A of the first tooth 411A, the second tooth 411B, and the third tooth 411C as an example. 1 is enlarged.

  As shown in FIG. 31 (enlarged view of the H portion in FIG. 30), the depth of the first stator groove 411A-1 near the center line of the tip portion of the first tooth 411A is W1.

  Further, as shown in FIG. 32 (enlarged view of J portion in FIG. 30), the depth of the first stator groove 411A-1 in the vicinity of the circumferential end of the tip of the first tooth 411A is W2.

  The depth of the first stator groove 411A-1 increases as it reaches the circumferential end of the tip of the first tooth 411A, and satisfies the relationship of W2> W1. The space between the vicinity of the center line of the tip portion of the first tooth 411A and the vicinity of the circumferential end portion of the tip portion of the first tooth 411A is gradually increased in the range of W1 to W2.

  With this configuration, the distortion of the induced voltage can be reduced, and in addition to the effect of reducing the eddy current, the iron loss can be suppressed by the induced voltage distortion and the noise can be reduced by reducing the torque ripple.

  FIGS. 33 to 36 are diagrams showing the first embodiment. FIG. 33 is a transverse sectional view of a stator 500 according to a fifth modification, FIG. 34 is an enlarged view of a portion K in FIG. 33, and FIG. 36 and 36 are enlarged views of a portion M in FIG.

  The stator 400 of the modification 4 has 9 slots, but the stator 500 of the modification 5 differs in that it has 6 slots.

  A stator 500 of Modification 5 will be described with reference to FIGS. 33 to 36. A stator 500 shown in FIG. 33 includes a substantially cylindrical stator core 510 and windings (not shown) inserted into slots 512 of the stator core 510 via an insulating material (not shown). At least.

  The cylindrical stator core 510 is formed by punching a thin electromagnetic steel sheet having a thickness of about 0.2 to 0.5 mm into a predetermined shape and laminating a predetermined number of sheets. The stator core 510 is formed by extending a plurality of first teeth 511E and second teeth 511F radially inward from a cylindrical core back 513 on the outer peripheral portion. Two first teeth 511E and second teeth 511F are sequentially formed in the clockwise direction, and then another two first teeth 511E and second teeth 511F are sequentially formed in the clockwise direction. Subsequently, another two first teeth 511E and second teeth 511F are sequentially formed in the clockwise direction. The plurality of first teeth 511E and second teeth 511F are formed at substantially equal intervals in the circumferential direction. Accordingly, the stator iron core 510 includes a total of six teeth: three first teeth 511E and three second teeth 511F.

  Slots 512 having the same shape are formed between the teeth (that is, between the first teeth 511E and the second teeth 511F (six locations). The teeth (first teeth 511E, second teeth 511F). The circumferential width D1 (see FIG. 33) is equal, and the plurality of first teeth 511E and second teeth 511F are formed at substantially equal intervals in the circumferential direction. The width in the circumferential direction increases toward the radial side, and a winding (not shown) is inserted into the slot 512 via an insulating material (not shown). Is a concentrated winding of three-phase Y connection formed by directly winding the number of turns.

  A notch 513 a is formed on the outer peripheral surface of the core back 513. The notch 513a is formed on the radial extension line of the teeth (first tooth 511E and second tooth 511F) so as not to narrow the magnetic path of the core back 513. These notches 513a serve as passages for refrigerant and refrigeration oil when the permanent magnet motor of the present embodiment is used in a hermetic compressor, for example. In the example of FIG. 33, the same number of six notches 513a as the teeth (the first teeth 511E and the second teeth 511F) are formed.

  The first teeth 511E and the second teeth 511F have a plurality of first stator grooves 511E-1 and second stator grooves 511F-1 extending in the axial direction at their tip portions (inner peripheral surfaces). Are formed respectively. And the phase with respect to the centerline of each teeth of the 1st stator groove | channel 511E-1 and the 2nd stator groove | channel 511F-1 differs, It is characterized by the above-mentioned.

  The stator core 510 of the modified example 5 is further provided with stator grooves (first stator grooves 511E-1 and second stator grooves) formed at the tips of the respective teeth (first teeth 511E and second teeth 511F). The stator groove 511F-1) is characterized in that the depth becomes larger as it becomes the circumferential end of the tip of the tooth.

  FIG. 34 (enlarged view of the K portion in FIG. 33) shows the first stator groove 511E-1 in an enlarged manner, taking the first tooth 511E of the first teeth 511E and the second teeth 511F as an example. ing.

  As shown in FIG. 35 (enlarged view of L portion in FIG. 34), the depth of the first stator groove 511E-1 in the vicinity of the center line of the tip portion of the first tooth 511E is W3.

  Also, as shown in FIG. 36 (enlarged view of the M portion in FIG. 34), the depth of the first stator groove 511E-1 in the vicinity of the circumferential end of the tip of the first tooth 511E is W4.

  The depth of the first stator groove 511E-1 increases as it reaches the circumferential end of the tip of the first tooth 511E, and satisfies the relationship of W4> W3. The space between the vicinity of the center line of the tip portion of the first tooth 511E and the vicinity of the circumferential end portion of the tip portion of the first tooth 511E is gradually increased in the range of W3 to W4.

  With this configuration, the distortion of the induced voltage can be reduced, and in addition to the effect of reducing the eddy current, the iron loss can be suppressed by the induced voltage distortion and the noise can be reduced by reducing the torque ripple.

  In addition, as a method of manufacturing the stator core, punching using a press machine is also possible, but when the stator groove formed by minute irregularities is punched by pressing as in the present embodiment, mechanical A plastic deformation layer is formed by the shearing, cutting, and breaking, and the iron loss is greatly increased by the punching strain.

  Therefore, for example, the iron loss of the stator can be drastically reduced by making it by photoetching without a plastic deformation layer.

  DESCRIPTION OF SYMBOLS 10 Stator core, 10A 1st core sheet, 10B 2nd core sheet, 10C 3rd core sheet, 11A 1st teeth, 11A-1 1st stator groove | channel, 11A-2 convex part, 11A- 3 concave portion, 11B second tooth, 11B-1 second stator groove, 11B-2 convex portion, 11B-3 concave portion, 11C third tooth, 11C-1 third stator groove, 11C-2 convex Part, 11C-3 recess, 12 slots, 13 core back, 13a notch, 100 stator, 110 stator core, 200 stator, 210 stator core, 211E first teeth, 211E-1 first stator Groove, 211E-2 convex portion, 211E-3 concave portion, 211F second tooth, 211F-1 Second stator groove, 211F-2 convex portion, 211F-3 concave portion, 212 slot 213, core back, 213a notch, 310 stator core, 310E first core sheet, 310F second core sheet, 311E first tooth, 311E-1 first stator groove, 311E-2 convex portion 311F 2nd teeth, 311F-1 2nd stator groove, 311F-2 convex part, 312 slot, 313 core back, 313a notch, 400 stator, 410 stator core, 411A 1st teeth, 411A -1 1st stator groove 411B 2nd tooth 411B-1 2nd stator groove 411C 3rd tooth 411C-1 3rd stator groove 413 Core back 413a Notch 500 Stator, 510 Stator iron core, 511E 1st tooth, 511E-1 1st stator groove, 511F 2nd tooth, 511F-1 Second stator groove, 512 slot, 513 core back, 513a notch.

Claims (7)

A permanent magnet type motor driven by an inverter controlled at a variable speed by PWM (Pulse Width Modulation) control, wherein a plurality of teeth are provided along the circumferential direction, and a slot is formed between adjacent teeth. In a permanent magnet type motor comprising a stator having an iron core, and a rotor disposed inside the stator,
The stator iron core is an electrical steel sheet of n (n is an integer of 2 or more) types in which a plurality of irregularities having a triangular cross section continuous in the circumferential direction of the pitch P are formed on the entire inner peripheral portion of each tooth A permanent magnet motor characterized in that n types of electrical steel sheets whose concave and convex positions are sequentially displaced in the circumferential direction by P / n are repeatedly laminated in the order described above. 2. The permanent magnet motor according to claim 1, wherein the pitch P is equal to or less than a thickness of the electromagnetic steel sheet. The permanent magnet motor according to claim 1 or 2, wherein a depth of the unevenness is equal to or greater than a thickness of the electromagnetic steel sheet. The permanent magnet motor according to any one of claims 1 to 3, wherein the depth of the unevenness is gradually increased toward the end in the teeth circumferential direction. The stator core is provided with a number of teeth that is an integer multiple of n,
The n types of electrical steel sheets are the same electrical steel sheet in which the positions of the unevenness of adjacent teeth are sequentially shifted in the circumferential direction by P / n,
The permanent magnet motor according to any one of claims 1 to 4, wherein the stator core is configured by laminating the same electromagnetic steel plates in the order described above while rotating by one tooth. The n types of electrical steel sheets are different electrical steel sheets in which the positions of the unevenness of each tooth are shifted in the circumferential direction by P / n in order between the electrical steel sheets,
5. The permanent magnet motor according to claim 1, wherein the stator iron core is configured by laminating the different electromagnetic steel sheets in the order without rotating. 6. The permanent magnet type motor according to claim 1, wherein at least the irregularities are processed by etching.

Images