JP2015073397A - Synchronous motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To alleviate stress concentration due to fitting and centrifugal force in a synchronous motor having a flux barrier.SOLUTION: A rotor 10 of a synchronous motor includes a rotor core 12, a permanent magnet slot and a squirrel-cage conductor slot 14. The permanent magnet slot includes a permanent magnet insertion part 16 to which a permanent magnet 15 is inserted and a pair of flux barriers 17 positioned on both ends in the circumferential direction of the permanent magnet insertion part 16 and sectioning a magnetic pole. The flux barrier 17 extends toward the outer diameter direction of the rotor 10 from a base end part 19 continuous to the permanent magnet insertion part 16 on a cross section orthogonal to the rotation shaft, and portion of a tip 21 thereof is provided with a straight line part 22 opposing a squirrel-cage conductor slot 14n closest to the tip 21, a leg part 20 extending in the direction of the tip 21 from the base end part 19 and the straight line part 22 provided in the tip 21 are connected via connection parts 23, and the connection parts 23 protrude to both sides in the circumferential direction from the leg part 20.

Description

  The present invention relates to a synchronous motor having a flux barrier.

  Synchronous motors mounted on various devices are required to have characteristics corresponding to the mounted devices. For example, a synchronous motor used in a synthetic fiber manufacturing process requires high specifications such as high-speed rotation and high output. In response to these demands, a so-called embedded permanent magnet (IPM type) synchronous motor in which a permanent magnet is embedded inside a rotor core has been widely proposed among synchronous motors.

  Further, such a synchronous motor generally has a problem of low starting performance, and in order to solve such a problem, an induction starting type synchronous motor having a cage conductor as described in the prior document 1 is also proposed. Has been. In this induction starting type synchronous motor described in the prior art document 1, a motor is started in the vicinity of the outer periphery of a rotor core in which a stator and a plurality of rectangular permanent magnets are embedded while being arranged perpendicular to each other in the radial direction. And a rotor provided with a squirrel cage conductor. The shaft is fastened to the rotor core by being inserted into the shaft hole with a tightening margin by shrink fitting or press fitting. The squirrel-cage conductor is constituted by a conductor bar inserted and disposed in a plurality of squirrel-cage conductor slots formed in the rotor core, and end rings that connect both ends of the conductor bar.

  The induction starting type synchronous motor having the above configuration can be directly supplied from a constant voltage single layer or three-phase power source (frequency 50 Hz or 60 Hz) without using an inverter. In this case, when the power is turned on, a cage conductor is used. The rotor rotates as an induction motor, reaches a synchronous speed, and then rotates as a synchronous motor by a permanent magnet. Even when an inverter is used, the synchronous speed can be reached without performing current control, and stable synchronous operation can be performed by the cage conductor.

  In the above-described permanent magnet embedded type synchronous motor, in order to increase the output efficiency, it is considered effective to reduce the leakage magnetic flux in the vicinity of the end portion of the permanent magnet. In some cases, a flux barrier (magnetic flux blocker) is provided. By forming such a flux barrier, the magnetic flux that is short-circuited inside the rotor core is interrupted, and it can be expected to reduce the leakage magnetic flux and increase the generated torque.

  As the shape of the flux barrier, for example, there is one formed as a rectangular shape connected to the end of the permanent magnet as shown as the first convex portion (12d-1) in FIGS. .

JP 2001-69696 A Japanese Patent Laid-Open No. 10-336927

  However, as described above, when an induction starting type synchronous motor having a cage conductor slot inside the rotor core is assumed, if a flux barrier is provided at the end of the permanent magnet, the flux barrier is increased with rotation. It is considered that the stress concentration due to the fitting and centrifugal force occurs between the cage conductor slot and the maximum stress becomes high, and the desired high-speed rotation cannot be performed. Also, when trying to increase the rotor thickness in order to reduce the fitting stress, the shaft must be made thinner to support insertion into the rotor core, and the critical speed is reduced. High-speed rotation may become impossible.

  Patent Document 2 specifies the width of the flux barrier in the circumferential direction and the distance between the flux barrier and the cage conductor slot for the purpose of relaxing the stress concentration between the flux barrier and the cage conductor slot. However, the shape of the flux barrier itself is not optimized, and it cannot be said that relaxation of stress concentration can be sufficiently achieved only by such a method.

  In addition, the above problem is not limited to the induction starting type synchronous motor including a squirrel-cage conductor, as long as it includes an insertion hole formed in the rotor core, an opening such as a recess formed in the outer periphery, The same problem due to stress concentration can occur depending on the positional relationship with the flux barrier.

  The present invention has been made in view of the above problems, and its purpose is to provide a high output by providing a flux barrier, and by fitting the shape and centrifugal force by optimizing its shape. An object of the present invention is to provide a synchronous motor that can realize high speed by relaxing stress concentration caused by the above.

  In order to achieve this object, the present invention takes the following measures.

  That is, the synchronous motor of the present invention comprises a rotor core that can be rotated around a rotation axis, a plurality of permanent magnet slots arranged in a circumferential direction inside the rotor core, and the rotating motor. A plurality of openings arranged along the rotation axis in the vicinity of the outer periphery of the core core, wherein the permanent magnet slot is a permanent magnet insertion portion for inserting a permanent magnet, and both circumferential ends of the permanent magnet insertion portion And a pair of flux barriers that divide the magnetic poles, and the flux barriers, in a cross section orthogonal to the rotation axis, from the base end portion continuous with the permanent magnet insertion portion toward the outer diameter direction of the rotor In addition, a straight portion facing the opening that is closest to the distal end portion is provided at a part of the distal end portion, and provided on the leg portion and the distal end portion that extend from the proximal end portion toward the distal end portion. Et And a straight line portion are connected via a connecting portion, the connecting portion and wherein the protruding on at least one side in the circumferential direction from the leg.

  When configured in this way, the flux barrier is provided so as to extend in the outer diameter direction of the rotor from the base end portion continuous with the permanent magnet insertion portion, thereby preventing a short circuit of magnetic flux around the flux barrier, Since the flow of magnetic flux can be optimized, the efficiency can be increased and a high output can be obtained.

  Furthermore, since the tip of the flux barrier is linear, the stress concentration around the tip of the flux barrier adjacent to the opening provided near the outer periphery of the rotor core is alleviated to reduce the maximum stress. It is also possible to realize high speed.

  Moreover, since the connection part protrudes from the leg part to at least one side in the circumferential direction, the stress generated at the end part of the linear part can be reduced, and the above effect can be enhanced.

  Furthermore, in order to reduce the stress generated at the end of the linear portion and the connecting portion at the tip of the flux barrier, further enhance the above effects, and achieve high output and high speed, in the cross section orthogonal to the rotation axis, the connection It is desirable that at least the portion radially outside the apex protruding in the circumferential direction of the portion is constituted by a smooth curve.

  In addition, in order to alleviate stress concentration on the surface of the flux barrier tip facing the opening and eliminate stress imbalance, the flux barrier tip is provided at the tip of the flux barrier in a cross section orthogonal to the rotation axis. It is effective that the straight line portion is inclined with respect to a straight line orthogonal to a straight line connecting the center of the opening closest to the tip and the rotation axis. Here, when the cross-sectional shape of the opening provided near the outer periphery of the rotor core is not circular, the center of gravity of the cross-sectional shape is defined as the center of the opening.

  In order to increase the strength of the rotor core by reducing the size of each permanent magnet insertion hole and increasing the strength of the rotor core without making the permanent magnet complicated, the permanent magnet insertion portion has an appropriate shape. The permanent magnet insertion portion constituting the slot is divided into a plurality of permanent magnet insertion holes in the circumferential direction, and the permanent magnet pieces constituting the permanent magnet are respectively inserted into the permanent magnet insertion holes. It is preferable to arrange the magnetic poles of the permanent magnet pieces so as to be oriented in the same direction in the radial direction.

  In the case where the shaft hole for inserting the shaft is provided in the rotor iron core, the permanent magnet insertion portion is disposed adjacent to the permanent magnet in order to reduce the stress concentration due to the fitting with the shaft and improve the strength. It is effective to arrange the insertion holes so that the insertion holes are convex toward the outer diameter direction.

  If the permanent magnet insertion hole is formed so as to be substantially rectangular in a cross section orthogonal to the rotation axis, it is possible to reduce the manufacturing cost by using a rectangular parallelepiped permanent magnet.

  Furthermore, in order to configure as an induction starting type synchronous motor that functions as an induction motor at the time of startup, each of the plurality of openings is configured as a cage conductor slot, and a conductor bar inserted into each cage conductor slot, It is preferable to provide a squirrel-cage conductor including an end ring that connects both ends of each conductor bar.

  And it becomes possible to attain efficiency improvement of a synthetic fiber manufacturing process by comprising as a synthetic fiber manufacturing apparatus provided with said synchronous motor.

  Since the present invention has the configuration described above, it is possible to improve torque by providing a flux barrier and obtain high output, and by optimizing the shape of the flux barrier, stress due to fitting, centrifugal force, etc. It is possible to realize high speed by relaxing the concentration. In addition, when the shaft is inserted into the rotor core, it can withstand the stress caused by fitting even if the shaft diameter is increased, so a thick shaft can be used, and the natural frequency is increased to achieve stable high-speed rotation. Can also be performed. With these effects, it is possible to provide a synchronous motor that achieves both high output and high speed.

Sectional drawing of the synchronous motor which concerns on embodiment of this invention. Sectional drawing of the rotor which comprises the synchronous motor shown in FIG. The principal part (E part) expanded sectional view of the rotor of FIG. The figure which shows the flow of the magnetic flux around a flux barrier. The schematic diagram which shows the example which changed the shape of the flux barrier front-end | tip part. The schematic diagram of the cross section which shows the edge part of a magnet insertion part. The expanded sectional view for demonstrating the detailed shape of a flux barrier. Sectional drawing which shows the modification of a flux barrier shape. Sectional drawing of the rotor which concerns on the modification in the case of a 2-pole synchronous motor. The principal part expanded sectional view which shows the modification at the time of employ | adopting this invention for a synchronous motor of a different type. Explanatory drawing which shows the view at the time of changing a flux barrier shape. Sectional drawing which shows the modification of the shape of a permanent magnet and a permanent magnet insertion part. Sectional drawing which shows the modification of a flux barrier shape. The principal part expanded sectional view of the modification shown in FIG.

  Hereinafter, a synchronous motor according to an embodiment of the present invention will be described with reference to the drawings. The synchronous motor according to the present embodiment shown in FIG. 1 is configured as an induction starting type synchronous motor including a cage conductor described later. FIG. 2 is a cross-sectional view showing an example of the rotor constituting the synchronous motor of the present invention, and is a cross-sectional view perpendicular to the rotation axis O serving as the rotation center of the rotor, and FIG. 3 is an enlarged cross-sectional view of the main part of the rotor. (E portion in FIG. 2).

  The synchronous motor shown in FIG. 1 has a three-phase stator 30 in which a stator winding (not shown) is wound in a stator winding slot 31 and a magnetic pole surface 32 of the stator 30 so as to face the stator 30. It has the rotor 10 which rotates inside. As shown in FIG. 2, the rotor 10 is fastened by inserting a shaft 40 arranged along the rotation axis O into the shaft hole 11 with a tightening margin by shrink fitting or press fitting. And four permanent magnet slots 13 arranged at equal intervals in the circumferential direction inside the rotor core, and provided inside the rotor core 12 and radially outside the permanent magnet slot 13. And a cage-shaped conductor slot 14 as a plurality of openings for inserting an aluminum conductor bar (not shown).

  The rotor core 12 is formed by laminating electromagnetic steel plates, suppresses eddy currents generated in the direction of the rotation axis O by the insulating film on the surface of each steel plate, and prevents a reduction in efficiency due to iron loss.

  The permanent magnet slot 13 includes a permanent magnet insertion portion 16 into which the permanent magnet 15 is inserted, a pair of flux barriers 17 that are positioned at both ends in the circumferential direction of the permanent magnet insertion portion 16 and define magnetic poles, and a gap portion 18. Yes.

  The permanent magnet insertion portion 16 is formed by being divided into two permanent magnet insertion holes 16a and 16b in the circumferential direction, and the permanent magnet 15 has two permanent magnet pieces 15a and 15b in each permanent magnet insertion hole 16a and 16b. The magnetic poles of these two permanent magnet pieces 15a and 15b are arranged so as to have the same polarity in the radial direction to form one magnetic pole (the magnetic pole center is shown in the figure). The dividing point D shown in FIG. The directions of the radial magnetic poles of the permanent magnet pieces 15a and 15b inserted into the permanent magnet insertion portions 16a and 16b constituting the permanent magnet slot 13 adjacent to these are reverse as shown in FIG. In addition, the permanent magnet insertion holes 16a and 16b adjacent to each other are formed so as to form a substantially rectangular shape in a cross section orthogonal to the rotation axis O, and the stress caused by fitting is maximized. FIG. It is inclined radially outward toward the center of the magnetic flux, that is, arranged so as to protrude toward the outer radial direction. The angle formed by the permanent magnet insertion holes 16a and 16b is 160 °. With this configuration, the permanent magnet pieces 15a and 15b can alleviate stress concentration without the portion closest to the shaft hole 11 becoming a corner.

  As shown in FIG. 2, the gap portion 18 is provided at the end portions of the permanent magnet insertion holes 16 a and 16 b facing each other. Specifically, as shown in the schematic diagram of FIG. Are formed as cavities into which the permanent magnet pieces 15a and 15b are not inserted. By doing so, the processing accuracy of the permanent magnet insertion hole 16 can be increased, the positional accuracy of the permanent magnet 15 can be increased, and the stress concentration can be reduced. It becomes possible. Instead of the shape of FIG. 6B, a small r may be formed at the corner as shown in FIG. However, in the case of FIG. 6B, the corner portion R of the permanent magnet insertion hole 16 can be made larger (r <R) than in the case of the configuration shown in FIG. It is preferable because stress concentration in the vicinity of the corner of the permanent magnet insertion hole 16 can be more effectively reduced.

  Hereinafter, the detailed shape of the flux barrier 17 (see FIG. 2) will be described. FIG. 7 is an enlarged view of the portion E in FIG. In the cross section orthogonal to the rotation axis O, the flux barrier 17 is connected to the permanent magnet insertion portion 16 and extends in the circumferential direction of the rotor 10. The flux barrier 17 changes the angle from the base end portion 19 and changes the rotor 10. A leg portion 20 extending in the outer diameter direction is provided, and a linear portion 22 facing the cage conductor slot 14n closest to the tip portion 21 is provided at a part of the tip portion 21 thereof. Moreover, the leg part 20 and the linear part 22 provided in the front-end | tip part 21 are connected via the connection part 23 comprised by a smooth curve.

  In the present specification, as shown in FIG. 7, the linear portion 22 and the connecting portion 23 are collectively defined as the distal end portion 21, and the flux barrier 17 is composed of the proximal end portion 19, the leg portion 20, and the like. It is comprised from the front-end | tip part 21. Further, the tip 21 is displaced outward in the circumferential direction by a distance d in FIG. 7 so as not to intersect the straight line L3 passing through the end face of the inserted permanent magnet piece 15a.

  In the present embodiment, as shown in FIG. 2, 40 cage-shaped conductor slots 14 are provided at equal intervals on the outer periphery of the rotor core, and four sets of eight fluxes at both ends of the permanent magnet slot 13 are provided. All the barriers 17 are arranged to face any one of the cage conductor slots 14.

  As shown in FIG. 3, the linear portion 22 constituting the flux barrier 17 connects the center P of the squirrel-cage conductor slot 14 n closest to the tip portion 21 and the rotation axis O in a cross section orthogonal to the rotation axis O. It is provided to be inclined with respect to the straight line L2 orthogonal to the straight line L1, and the inclination angle θ with respect to the straight line L2 is set to 10 ° in this embodiment.

  As shown in FIG. 7, the connection portion 23 protrudes from the leg portion 20 on both sides in the circumferential direction, and the connection portion 23, the leg portion 20, and the straight portion 22 form a substantially T shape.

  In addition, what is necessary is just to optimize the shape of the front-end | tip part 21 of the flux barrier 17 by the idea that it forms so that the stress in the surface facing the nearest cage-shaped conductor slot 14n may become equal. That is, FIG. 5 shows five typical shapes of the tip 21 (a) to (e), but by numerically analyzing the stress at each tip (a) to (e). The proper shape is determined. Here, the tip shape of (a) has been used conventionally and constitutes Comparative Example 1, and (b) constitutes Comparative Example 2 with a straight portion provided at the tip. Is. Moreover, (c)-(e) comprises 1st Embodiment-3rd Embodiment. Among these, the tip shape of (e) corresponding to the third embodiment schematically represents the shape adopted in the flux barrier 17 described in FIGS.

  Specifically, when the tip 21 is first shaped like a semicircular shape (a), stress concentrates on X1 closest to the cage conductor slot 14n. Therefore, if the convex portion is eliminated by providing the straight portion 22 on the surface facing the cage conductor slot 14n as shown in (b), the maximum stress can be reduced by avoiding stress concentration at one point. . However, since stress tends to concentrate on the corner X2, if the left and right symmetrical T-shape as shown in (c) is reduced in order to reduce the stress of X2, the straight portion 22 and the connecting portions 23a and 23b on both sides are connected. Stress concentrates around the connection point (X3, X4), and a difference also occurs between the stresses at both ends (in FIG. 5, the stress at X3 <the stress at X4). Therefore, the connecting portion 23b on the X4 side where the stress is large is extended in the circumferential direction of the two connecting points X3 and X4, and X4 is separated from the cage conductor 14n in the circumferential direction as shown in (d). Further, when the straight portion 22 is tilted in order to reduce the difference in stress, X4 further deviates from the cage conductor 14n to have a shape as shown in (e), and the equalization of the stresses of X3 and X4 is achieved.

  Since the actual shape is changed depending on conditions such as the rotational speed, torque, and fitting stress of the synchronous motor, the shape as shown in (e) is not always optimal, and the shape of the tip is not limited to the above-mentioned various shapes. Depending on conditions, it can be changed for the purpose of equalizing the stress on the surface facing the cage conductor slot. For example, the target performance may be obtained by the shape of (c) or (d).

  Similarly, the inclination angle θ of the linear portion 22 shown in FIG. 3 is not limited to the above-described 10 °, and various conditions such as a target output torque, a maximum rotation speed, and a shrinkage fit suitable for the rotation speed. It is also possible to change the tilt angle according to the above. At this time, when the inclination angle θ is changed, a negative angle, that is, a case where the inclination angle θ is inclined in the opposite direction is also included.

  Next, the operation in the above embodiment will be described.

  In FIG. 1, when a current flows through the stator 30 winding and a rotating magnetic field is generated inside the stator 30, the rotor 10 starts rotating by obtaining torque by an induced current generated in a cage conductor (not shown). When the synchronous speed is reached, the permanent magnet 15 rotates as a synchronous motor.

  During rotation as a synchronous motor, as shown in FIG. 7, the flux barrier 17 extends from the base end portion 19 toward the outer diameter direction of the rotor 10. Since a path through which the q-axis magnetic flux flows radially inward can be secured, an improvement in pull-in torque that is a torque that keeps the rotor 10 synchronized and an escape torque that is a maximum torque that keeps the synchronization when the rotation increases can be expected.

  Also, numerical analysis is performed when the present embodiment is adopted. When the shrink fit and the rotational speed are compared under the same conditions, the maximum stress when the shapes of the flux barrier tip 21 and the permanent magnet hole 16 are as shown in FIG. a) The shape of the permanent magnet hole 16 was about 1/3 of that shown in FIG. 6B. From this result, it was shown that if this embodiment is adopted, the stress distribution is improved and the stress concentration is relaxed.

  As described above, the synchronous motor according to the present embodiment constitutes the rotor 10 and includes a rotor core 12 that can rotate around the rotation axis, and a plurality of circumferentially arranged rotor cores 12 within the rotor core 12. The permanent magnet slot 13 includes a permanent magnet slot 13 and a cage conductor slot 14 as a plurality of openings arranged along the rotation axis O in the vicinity of the outer periphery of the rotor core 12. A permanent magnet insertion portion 16 to be inserted and a pair of flux barriers 17 positioned at both ends in the circumferential direction of the permanent magnet insertion portion 16 and defining magnetic poles. The flux barrier 17 is permanent in a cross section orthogonal to the rotation axis O. A squirrel-cage conductor slot that extends in the outer diameter direction of the rotor 10 from the base end portion 19 that is continuous with the magnet insertion portion 16 and that is closest to the tip portion 21 at a part of the tip portion 21. 14n and the linear part 22 which opposes, the leg part 20 extended in the front-end | tip part 21 direction from the base end part 19, and the linear part 22 provided in the front-end | tip part 21 are connected via the connection part 23, The connecting portion 23 is configured to protrude from the leg portion 20 on both sides in the circumferential direction.

  Since it is configured in this way, the flux barrier 17 is provided so as to extend in the outer diameter direction of the rotor 10 from the base end portion 19 continuous with the permanent magnet insertion portion 15. Since the short circuit of the magnetic flux can be prevented and the flow of the magnetic flux can be optimized, it is possible to increase the efficiency and obtain a high output.

  Furthermore, since the tip 21 of the flux barrier 17 is linear, the stress concentration around the tip 21 of the flux barrier 17 adjacent to the cage conductor slot 14 of the rotor core 12 is alleviated and maximized. It is also possible to achieve high speed by reducing stress. Moreover, when it is set as the structure which inserts the shaft 40 in the rotor core 12, the diameter of the shaft 40 does not need to make thin and a fall of dangerous speed does not arise.

  Further, since the connecting portion 23 protrudes from the leg portion 20 on both sides in the circumferential direction, the stress generated at the connection points X3 and X4 between the straight portion 22 and the connecting portion 23 can be reduced, and the above effect can be enhanced. It becomes possible.

  Furthermore, in the cross section orthogonal to the rotation axis O, the connecting portion 23 is configured by a smooth curve, so that the stress generated at the end of the straight portion 22 and the connecting portion 23 at the tip 21 of the flux barrier 17 is reduced. It is possible to enhance the above effects and achieve high output and high speed.

  Further, in a cross section orthogonal to the rotation axis O, a straight line portion 22 provided at the tip portion 21 of the flux barrier 17 connects the center P of the cage conductor slot 14n closest to the tip portion 21 and the rotation axis O. Since it is configured to be inclined with respect to the straight line L2 orthogonal to the straight line L1, stress concentration on the surface of the flux barrier tip 21 facing the cage conductor slot 14 can be alleviated, and stress unbalance can be eliminated. It is possible.

  A permanent magnet insertion portion 16 constituting the one-pole permanent magnet slot 13 is divided into a plurality of permanent magnet insertion holes 16a, 16b,... In the circumferential direction, and each permanent magnet insertion hole 16a, 16b,. Are inserted into the permanent magnet 15 and the magnetic poles of the permanent magnet pieces 15a, 15b,... Are arranged in the radial direction so as to have the same polarity. In addition to making the permanent magnet 15 into an appropriate shape without making the permanent magnet 15 into a complicated shape, it is possible to increase the strength of the rotor core 10 by reducing the size of each permanent magnet insertion hole 16. It has become.

  Since the permanent magnet insertion portion 16 is arranged so that the adjacent permanent magnet insertion holes 16a, 16b,... Are convex in the outer diameter direction, the stress concentration due to the fitting is alleviated, and more Strength can be improved.

  Since the permanent magnet insertion hole 16 is formed to be substantially rectangular in a cross section orthogonal to the rotation axis O, it is possible to reduce the manufacturing cost by using a rectangular parallelepiped permanent magnet. It has become.

  Furthermore, a plurality of openings are each configured as a cage conductor slot, and a cage conductor including a conductor bar inserted into each cage conductor slot 14 and an end ring connecting both ends of each conductor bar is provided. Thus, it is possible to provide an induction starting type synchronous motor that functions as an induction motor at the time of starting while effectively utilizing the features of the flux barrier 17 configured as described above.

  The specific configuration of each unit is not limited to the above-described embodiment.

  For example, in the above embodiment, the connection portion 23 of the flux barrier 17 protrudes from the leg portion 20 on both sides in the circumferential direction, but one side may not protrude as long as stress distribution is achieved. Further, the straight line portion 22 is not necessarily a complete straight line, and may be allowed to have a non-linear shape such as a gentle curve as long as stress distribution is achieved. Further, as shown in FIG. 8A, the flux barrier 117 may have a shape in which the base end portion 119 is shortened and the leg portion 120 continuously extends from the permanent magnet insertion hole 116 directly in the outer diameter direction. Good. Further, as shown in FIG. 7, the tip 21 has been displaced outward in the circumferential direction by a distance d from a straight line L3 passing through the end face of the permanent magnet piece 15a. However, a reduction in efficiency due to hindering the q-axis magnetic flux is allowed. In this case, the tip 21 may intersect with the straight line L3.

  In the above-described embodiment, each permanent magnet slot 13 includes the flux barriers 17 and 17 at both ends in the circumferential direction, and the flux barriers 17 to 17 are independent from each other. The two adjacent flux barriers 17 and 17 formed in the magnet slots 13 and 13 can be formed so that a part thereof is continuous, and even in such a case, according to the above-described embodiment such as reduction of the maximum stress. An effect can be obtained. Furthermore, as one form thereof, as shown in FIG. 13, two adjacent permanent magnet slots 613 and 613 may be provided with one flux barrier 617 shared. Also in this case, as in the above-described embodiment, the four permanent magnet slots 613 arranged at equal intervals in the circumferential direction inside the rotor core 612 constituting the rotor 610 are provided with permanent magnets 615a and 615b, respectively. Permanent magnet insertion holes 616a and 616b to be inserted and gap portions 618 formed at the ends facing each other, and permanent magnet insertion provided in adjacent permanent magnet slots 613 and 613 by a flux barrier 617, respectively. The holes 616a and 616b are connected to each other. That is, as shown in FIG. 14, the flux barrier 617 includes base end portions 619 and 619 that are continuous with permanent magnet insertion holes 616a and 616b that constitute two adjacent permanent magnet slots 613, and these two base end portions. 619, 619 and one leg portion 620 connected to the leg portion 620, and one tip portion 621 existing in the outer diameter direction of the leg portion 620. A part of the tip 621 is provided with a straight part 622 that faces the cage conductor slot 14n closest to the tip 621, and the leg 620 and the straight part 622 are connected via a connection part 623. Has been.

  In other words, the flux barrier 617 extends from the proximal end portion 619 continuous with the permanent magnet insertion portion 616a toward the outer diameter direction of the rotor 610, and is closest to the distal end portion 621 at a part of the distal end portion 621. A straight portion 622 facing the cage-shaped conductor slot 14n is provided. The leg portion 620 extending from the base end portion 619 toward the distal end portion 621 and the straight portion 622 provided at the distal end portion 621 are connected to the connecting portion 623. The connection portion 623 is configured to protrude from the leg portion 620 on both sides in the circumferential direction.

  Further, in the present embodiment, the connecting portion 23 is configured by a smooth curve as a whole, but it is not always necessary to have such a configuration, and as shown in FIG. It suffices if the portion radially outside the vertices Y1 and Y2 that protrude the most is a smooth curve. Specifically, when the vertices Y1 and Y2 are connected by a straight line L5, a portion that is radially outward from the straight line L5 with the straight line L5 as a boundary is an outer connecting portion 23a, and a portion that is inward is an inner connecting portion 23b. The outer connecting portion 23a has a relatively large stress even in the entire contacting side portion 23. Therefore, the inner connecting portion 23b does not have a relatively large stress. Therefore, it is not necessary to be constituted by a smooth curve. In addition, when the part which protruded most in the circumferential direction among the connection parts 23 mentioned above is comprised by the straight line which makes the same direction as radial direction, apexes Y1 and Y2 should be set as the center position of the straight line. Is enough.

  Permanent magnet slots 13 are preferably provided at equal intervals from the standpoint of ease of design and manufacture, and from the balance of mass centered on the rotation axis O and the balance of driving force. However, depending on the specifications of the motor, the path of magnetic flux may be provided. As long as they are provided intermittently, that is, spaced apart from each other, it is not always necessary to provide them at regular intervals.

  Further, as shown in FIG. 8B, the permanent magnet piece 215 is made shorter than the length in which the permanent magnet piece 215 can be originally inserted into the permanent magnet insertion portion 216, and is continuous with the end of the permanent magnet piece 215. The whole portion extending in the circumferential direction may be the base end portion 219.

  Further, in the above embodiment, the permanent magnet pieces 15a and 15b and the permanent magnet insertion holes 16a and 16b are rectangular, but the permanent magnet pieces 515a and 515b and the permanent magnet insertion holes 516a and 516b are formed as shown in FIG. When formed in a substantially arc shape in cross-section, a high effect can be obtained due to stress relaxation between the permanent magnet insertion portions 516a and 516b and the shaft hole 11. Further, by arranging the arcs formed by the permanent magnet insertion holes 516a and 516b so as to be concentric with the shaft hole 11, the stress can be more effectively relieved. Also in this configuration, as in the above-described embodiment, the four permanent magnet slots 513 arranged at equal intervals in the circumferential direction inside the rotor core 512 constituting the rotor 510 have both circumferential ends. Flux barriers 517 and 517 are provided, and the gaps 518 are provided at the ends of the permanent magnet insertion holes 516a and 516b facing each other.

  In the above embodiment, the permanent magnet 15 constituting one magnetic pole is divided into the permanent magnet pieces 15a and 15b. However, it is possible to constitute one magnetic pole by a single permanent magnet piece. In this case, by using an arc magnet formed in an arc shape as the permanent magnet, it is possible to further reduce stress and improve efficiency. Further, as in the configuration in which the permanent magnet is divided into a plurality of permanent magnet pieces, even in a configuration in which a single permanent magnet piece is provided, when a plurality of the permanent magnet pieces are arranged, the shaft hole 11 is substantially concentric for stress relaxation. It is preferable to arrange so that.

  In the above embodiment, the cage conductor slot 14n has a circular cross section. However, the present invention can be applied to a cage conductor having a cross section other than a circle. In that case, it is only necessary to set the center of gravity of the cross section as the center P described above.

  The above embodiment is a 4-pole synchronous motor (two permanent magnet pieces per pole), but is configured as a 2-pole synchronous motor (three permanent magnet pieces per pole) as shown in FIG. It is also possible to do. In this modification, 28 cage-shaped conductor slots 314 are provided at equal intervals on the outer peripheral portion of the rotor core 312 constituting the rotor 310, and three permanent magnet pieces 315a and 315b are provided radially inside thereof. , 315c are arranged so that the magnetic poles are oriented in the same direction in the radial direction. Four flux barriers 317 are installed at both ends of each pole, for a total of four, and all face one of the cage conductor slots 314. Moreover, in the said structure, the space | gap part 318 provided between the permanent magnet pieces 315a, 315b, 315c in the same pole short-circuits between each magnetic pole of the single permanent magnet pieces 315a, 315b, 315c. It also serves as a prevention. Also in this modification, the flux barrier 317 can have the above-described shape including the base end portion 19, the leg portion 20, and the tip end portion 21.

  Further, the present invention can be suitably applied to a permanent magnet embedded type synchronous motor having a form as shown in FIG. 10, for example, other than the induction starting type synchronous motor. In this configuration, a plurality of recesses 414 are formed as openings along the rotation axis O on the outer periphery of the rotor core. Even in such a case, the same effect can be obtained by configuring the position and shape of the flux barrier 17 with respect to the concave portion 414 in the same manner as described above. In this case, the center P of the recess 414 may be considered as the position of the center of gravity in the region formed by the virtual circle Ci and the recess 414 along the outer periphery of the rotor core 412 in the cross section orthogonal to the rotation axis O. .

  In addition, when configured as a synthetic fiber manufacturing apparatus including the above-described synchronous motor, it is possible to improve the efficiency of the synthetic fiber manufacturing process. Specifically, when configured as a drive source for a large roller such as a godet roller that constitutes the synthetic fiber manufacturing apparatus, the heavy roller can be rotated at a high speed according to the fiber manufacturing process. Further, when configured as a drive source for a take-up spindle for winding the fiber, a relatively long rotating body can be rotated at a high speed with a heavy article called a fiber winding body added thereto.

  Other configurations can be variously modified without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Rotor 12 ... Rotor core 13 ... Permanent magnet slot 14, 14n ... Opening (cage-shaped conductor slot)
DESCRIPTION OF SYMBOLS 15 ... Permanent magnet 15a, 15b ... Permanent magnet piece 16 ... Permanent magnet insertion part 16a, 16b ... Permanent magnet insertion hole 17 ... Flux barrier 19 ... Base end part 20 ... Leg part 21 ... Tip part 22 ... Linear part 23 ... Connection part 40 ... shaft L1, L2, L3 ... straight line P ... center of (opening) O ... rotation axis

Claims (6)

A rotor core that constitutes a rotor and is rotatable about a rotation axis, a plurality of permanent magnet slots arranged in a circumferential direction inside the rotor core, and a rotation axis near the outer periphery of the rotor core A synchronous motor having a plurality of openings disposed along the
The permanent magnet slot includes a permanent magnet insertion part for inserting a permanent magnet and a pair of flux barriers positioned at both ends in the circumferential direction of the permanent magnet insertion part and defining magnetic poles,
The flux barrier extends in the outer diameter direction of the rotor from a base end portion continuous with the permanent magnet insertion portion in a cross section orthogonal to the rotation axis, and a part of the tip portion thereof is provided at the tip portion. A straight portion facing the closest opening is provided, and a leg portion extending from the proximal end portion toward the distal end portion and the straight portion provided at the distal end portion are connected via a connecting portion, and The synchronous motor is characterized in that the connecting portion protrudes from the leg portion to at least one side in the circumferential direction.   2. The synchronous motor according to claim 1, wherein in a cross section orthogonal to the rotation axis, at least a portion radially outside a vertex protruding in the circumferential direction of the connection portion is formed by a smooth curve. .   In a cross section perpendicular to the rotation axis, a straight line portion provided at the tip of the flux barrier is inclined with respect to a straight line perpendicular to a straight line connecting the center of the opening closest to the tip and the rotation axis. The synchronous motor according to claim 1, wherein the synchronous motor is provided.   A permanent magnet insertion portion constituting one permanent magnet slot is formed by being divided into a plurality of permanent magnet insertion holes in the circumferential direction, and a permanent magnet piece constituting the permanent magnet is inserted into each permanent magnet insertion hole. The synchronous motor according to any one of claims 1 to 3, wherein the synchronous motor is inserted so that the magnetic poles of the permanent magnet pieces are oriented in the same direction in the radial direction.   Each of the plurality of openings is configured as a cage conductor slot, and a cage conductor including a conductor bar inserted into each cage conductor slot and an end ring connecting both ends of each conductor bar is provided. The synchronous motor according to any one of claims 1 to 4, characterized in that:   The synthetic fiber manufacturing apparatus provided with the synchronous motor in any one of Claims 1-5.

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