JP6585974B2 - Permanent magnet motor - Google Patents

Description

  The present invention relates to a permanent magnet motor including a rotor in which a permanent magnet is disposed, and more particularly to a technique for improving the efficiency of the permanent magnet motor.

For example, a permanent magnet motor disclosed in Patent Document 1 is used as an electric motor for driving various devices such as a compressor mechanism of a compressor, a vehicle, and an in-vehicle device mounted on the vehicle.
The permanent magnet motor disclosed in Patent Document 1 includes a stator and a rotor that is rotatably disposed in the stator via a gap (air gap). In the rotor, main magnetic pole portions and auxiliary magnetic pole portions are alternately arranged along the circumferential direction. A magnet insertion hole extending along the circumferential direction is formed in the main magnetic pole portion, and a permanent magnet is inserted into the magnet insertion hole. The stator has a yoke portion extending along the circumferential direction and a teeth portion extending from the yoke portion along the radial direction in the rotation center direction. A tooth tip surface is formed on the tip side of the tooth portion. A slot is formed by teeth portions adjacent in the circumferential direction, and a stator winding is inserted into the slot. The outer peripheral surface of the rotor is formed in a circular shape when viewed in a cross section perpendicular to the axial direction. That is, the gap between the stator and the rotor (the gap between the teeth tip surface of the teeth portion of the stator and the outer peripheral surface of the rotor) is set to be constant.
The permanent magnet motor disclosed in Patent Document 1 can use a magnet torque by a permanent magnet and a reluctance torque by saliency.

Japanese Patent Laying-Open No. 2015-47212

In the permanent magnet motor disclosed in Patent Document 1, the gap between the tooth tip surface of the teeth portion of the stator and the outer peripheral surface of the rotor is constant. For this reason, magnetic flux generated from both end portions of the permanent magnet along the circumferential direction (hereinafter referred to as “end portions of the permanent magnet”) flows to the teeth portion of the stator via the outer peripheral surface of the auxiliary magnetic pole portion. The amount of magnetic flux flowing through the magnetic pole part, that is, the amount of effective magnetic flux decreases. Further, the magnetic flux generated by the current flowing through the stator winding flows on the outer peripheral surface of the auxiliary magnetic pole portion, and the magnetic flux is concentrated on both end portions of the permanent magnet to demagnetize the permanent magnet. As a method for coping with the decrease in the effective magnetic flux amount and the demagnetization of the permanent magnet, for example, a method of increasing the current flowing through the stator winding is conceivable. However, increasing the current flowing through the stator winding increases the copper loss. As described above, in the permanent magnet motor disclosed in Patent Document 1, the amount of effective magnetic flux is reduced, and the magnetic flux is concentrated and demagnetized at both ends of the permanent magnet.
The present invention was devised in view of such points, and increases the amount of effective magnetic flux and prevents the magnetic flux from concentrating at both ends of the permanent magnet to improve the efficiency of the permanent magnet motor. With the goal.

1st invention and 2nd invention are equipped with the stator and the rotor arrange | positioned through the space | gap in a stator, and a rotor sees in a cross section orthogonal to an axial direction, and a main magnetic pole part and an auxiliary | assistant magnetic pole part The present invention relates to a permanent magnet motor in which magnets are alternately arranged along a circumferential direction, a magnet insertion portion is provided in a main magnetic pole portion, and a permanent magnet is inserted in the magnet insertion portion.
In the first invention, the magnet insertion portion is formed in a V shape in which the central portion along the circumferential direction protrudes from the both end portions to the outer peripheral side of the rotor when viewed in a cross section perpendicular to the axial direction. It is composed of holes. The magnet insertion hole includes a linear first inner wall and a first outer wall extending in parallel, a linear second inner wall and a second outer wall extending in parallel, and a linear first outer peripheral wall. It has a second outer peripheral wall, a linear first end wall, and a second end wall. One side of the V shape is formed by the first inner wall, the first outer wall, the first outer peripheral wall, and the first end wall, and the second inner wall, the second outer wall, the second outer peripheral wall, The second end wall forms the other side of the V shape, and the first end wall extends in parallel with the second end wall of the adjacent main magnetic pole portion.
The permanent magnet includes a first permanent magnet piece inserted into one side of the V-shaped magnet insertion hole and a second permanent magnet inserted into the other side of the V-shaped magnet insertion hole. It is comprised by the magnet piece. The first permanent magnet piece and the second permanent magnet piece have a linear inner wall and an outer wall extending in parallel, a linear end wall on one side, and an end wall on the other side.
The first permanent magnet is formed in the magnet insertion hole so that a first space portion is formed between one end wall of the first permanent magnet piece and the first end wall of the magnet insertion hole. The second space portion is formed between the first positioning portion for positioning the piece, and the second end wall of the second permanent magnet piece and the second end wall of the magnet insertion hole. A second positioning portion for positioning the permanent magnet piece is provided.
The outer peripheral surface of the rotor is formed so that the gap interval along the q-axis of the auxiliary magnetic pole portion is longer than the gap interval along the d-axis of the main magnetic pole portion when viewed in a cross section perpendicular to the axial direction. Has been.
In the second invention, the magnet insertion portion is viewed from a cross section perpendicular to the axial direction, and the central portion along the circumferential direction is located on the one side and the other side along the circumferential direction across the bridge portion from both ends. It is comprised by the 1st magnet insertion hole and the 2nd magnet insertion hole which are arrange | positioned in the V shape which protrude | jumped out to the outer peripheral side. The first magnet insertion hole and the second magnet insertion hole have linear inner and outer walls extending in parallel, a linear outer peripheral wall, a linear end wall on one side, and an end wall on the other side. ing. One side of the V-shape is formed by the first magnet insertion hole, the other side of the V-shape is formed by the second magnet insertion hole, and one end wall of the first magnet insertion hole Extends parallel to the other end wall of the second magnet insertion hole of the adjacent main magnetic pole portion.
The permanent magnet includes a first permanent magnet piece inserted into the first magnet insertion hole and a second permanent magnet piece inserted into the second magnet insertion hole. The first permanent magnet piece and the second permanent magnet piece have a linear inner wall and an outer wall extending in parallel, a linear end wall on one side, and an end wall on the other side.
In the first magnet insertion hole, a first space portion is formed between one end wall of the first permanent magnet piece and one end wall of the first magnet insertion hole. Are provided with a first positioning portion for positioning the first permanent magnet piece, and the second magnet insertion hole has an end wall on the other side of the second permanent magnet piece and the other side of the second magnet insertion hole. A second positioning portion for positioning the second permanent magnet piece is provided so that a second space is formed between the end wall of the first permanent magnet.
The outer peripheral surface of the rotor is formed so that the gap interval along the q-axis of the auxiliary magnetic pole portion is longer than the gap interval along the d-axis of the main magnetic pole portion when viewed in a cross section perpendicular to the axial direction. Has been.
Various permanent magnets such as ferrite magnets, rare earth magnets, neodymium magnets containing terbium and dysprosium can be used as the permanent magnets.
The first space portion and the second space portion can prevent the magnetic flux generated from both ends of the permanent magnet from being short-circuited.
The outer peripheral surface of the rotor preferably has an air gap interval in a region on both sides of a portion where the outer peripheral surface of the rotor intersects with the q axis in a direction where the outer peripheral surface of the rotor intersects with the q axis. It is formed to gradually become longer. More preferably, it is configured by combining outer peripheral portions formed in an arc shape. Of course, the outer peripheral surface of the rotor can be formed in various shapes combining curves and straight lines.
In the first invention and the second invention , the permanent magnets of the main magnetic pole portion of the rotor are arranged in a protruding shape. Thereby, a magnet surface area increases and the amount of magnetic flux (effective magnetic flux amount) which flows through a main magnetic pole part increases. And since the electric current which flows into a stator winding | coil can be made small by the increase in magnetic flux amount, a copper loss can be reduced.
Further, the permanent magnets are arranged in a protruding shape protruding to the outer peripheral side. Thereby, the space | interval between the both ends along the circumferential direction of a permanent magnet and the outer peripheral surface of a rotor becomes small, and between the both ends of the said permanent magnet along the circumferential direction and the outer peripheral surface of a rotor. The reluctance torque generated by the magnetic flux passing through is reduced. By reducing the reluctance torque, the iron loss is reduced. On the other hand, since the distance between the permanent magnet and the outer peripheral surface of the rotor is reduced, the decrease in the amount of magnetic flux due to the armature reaction is greatly suppressed. Thereby, while being able to reduce an iron loss, the amount of magnetic flux (effective magnetic flux amount) can be increased and efficiency improves.
In particular, in the first invention and the second invention , the permanent magnets are arranged in a V shape. Thereby, the center part of the permanent magnet along the circumferential direction (the end walls on the d-axis side of the first and second permanent magnet pieces arranged on both sides of the d-axis) and the outer peripheral surface of the rotor The interval between them can be reduced. Accordingly, it is possible to further suppress a decrease in the effective magnetic flux amount due to the armature reaction.
The outer peripheral surface of the rotor is formed such that the gap interval along the q axis of the auxiliary magnetic pole portion is longer than the gap interval along the d axis of the main magnetic pole portion. Thereby, compared with the case where the space | gap between the internal peripheral surface of a stator and the outer peripheral surface of a rotor is constant (the outer peripheral surface of a rotor is formed in the circular shape), it is from both ends of a permanent magnet. The generated magnetic flux can be used effectively (the effective magnetic flux can be increased), and the magnetic flux flowing from the teeth portion of the stator to the rotor side is prevented from concentrating on both ends of the permanent magnet. it can.
Moreover, a permanent magnet can be positioned in a magnet insertion part by a positioning part. As a result, it is possible to form a space portion of a predetermined shape at both ends of the magnet insertion portion without greatly changing the shape of the magnet insertion portion, and to reliably prevent short-circuiting of magnetic flux at both ends of the permanent magnet. it can.
Therefore, the permanent magnet motors of the first invention and the second invention can improve the efficiency as compared with the conventional permanent magnet motor.
In a different form of the first invention and the second invention , the outer peripheral surface of the rotor has a first outer peripheral portion that intersects the d-axis of the main magnetic pole portion and a second outer peripheral portion that intersects the q-axis of the auxiliary magnetic pole portion. It is formed by being connected alternately. The first outer peripheral portion is formed in an arc shape having a center point on the d axis. The second outer peripheral portion has a center point on the q axis and is formed in an arc shape having a radius larger than the radius of the first outer peripheral portion. Preferably, the arc shape of the first outer peripheral portion is formed in an arc shape with the center of rotation as the center point, and the second outer peripheral portion is on the q axis, and the second outer peripheral portion from the center of rotation is It is formed in a circular arc shape with a point away from the opposite side as a center point.
In this embodiment, the outer peripheral surface of the rotor can be easily formed. Moreover, when the connection part of a 1st outer peripheral part and a 2nd outer peripheral part passes through the location which opposes a teeth part, the rapid change of the magnetic flux amount which flows into a teeth part can be suppressed. As a result, it is possible to prevent an increase in the harmonic component contained in the waveform of the induced voltage (electromotive force waveform) induced in the stator winding due to a sudden change in the amount of magnetic flux flowing through the tooth portion. The position of the rotor can be accurately detected based on the electromotive force waveform of the winding. Therefore, when using a sensorless control type control device that detects the position of the rotor based on the electromotive force waveform of the stator winding, it is possible to prevent a decrease in efficiency due to a decrease in the position detection accuracy of the rotor .
The third invention relates to a device driving apparatus. The device driving apparatus of the present invention includes a device (for example, a compressor mechanism of a compressor, a vehicle, a vehicle-mounted device mounted on the vehicle) and an electric motor that drives the device, and is one of the permanent magnet motors described above as the motor. Is used.
The present invention has the same effect as the permanent magnet motor described above.

  In the present invention, the efficiency of the permanent magnet motor can be improved.

It is sectional drawing of 1st Embodiment of the permanent magnet electric motor of this invention. It is the elements on larger scale of FIG. It is sectional drawing of 2nd Embodiment of the permanent magnet electric motor of this invention. FIG. 4 is a partially enlarged view of FIG. 3.

Embodiments of a permanent magnet motor according to the present invention will be described below with reference to the drawings.
In this specification, the description of “axial direction” indicates the direction of the rotation center line passing through the rotation center of the rotor (rotating shaft) in a state where the rotor is rotatably arranged with respect to the stator. The description “circumferential direction” indicates a circumferential direction centered on the center of rotation when viewed in a cross section perpendicular to the axial direction in a state where the rotor is rotatably arranged with respect to the stator. The description “radial direction” indicates a direction passing through the center of rotation when viewed in a cross section perpendicular to the axial direction in a state where the rotor is rotatably arranged with respect to the stator. “D-axis” represents a line connecting the rotation center and the circumferential center point of the main magnetic pole portion, and “q-axis” represents a line connecting the rotation center and the circumferential center point of the auxiliary magnetic pole portion.
In addition, the “inner wall” and “outer wall” of the magnet insertion portion (magnet insertion hole) are arranged on the rotation center side of the radially opposed walls to form a portion for inserting a permanent magnet (permanent magnet piece). The outer wall and the wall disposed on the outer peripheral side of the rotor are represented by “the outer peripheral wall”, both end portions along the circumferential direction of the magnet insertion portion (the both end walls of the permanent magnet and the both end walls of the magnet insertion portion). Represents a wall formed in parallel (including “substantially parallel”) to the outer peripheral surface of the rotor to form a space portion, and “end wall” is an adjacent magnet insertion portion (magnet insertion hole) It represents the wall on the opposite side. The “inner wall” and “outer wall” of the permanent magnet (permanent magnet piece) are a wall and a rotor arranged on the rotation center side among the radially opposing walls in a state where the permanent magnet is inserted into the magnet insertion portion. The “end wall” represents a wall facing the adjacent permanent magnet (permanent magnet piece).
The description “parallel” is used to include “substantially parallel”.

  In addition, each embodiment of the permanent magnet motor of the present invention described below includes, for example, a compressor mechanism of a compressor provided in an air conditioner, a cooling device, a refrigeration device, and the like, a vehicle, and a vehicle mounted on the vehicle. It can be used as an electric motor for driving various known devices such as devices. That is, this invention can also be comprised as an apparatus drive device provided with an apparatus and the permanent magnet electric motor which drives an apparatus. Since the configuration of each device is known, the description thereof is omitted in this specification.

1 and 2 show a first embodiment of a permanent magnet motor of the present invention. FIG. 1 is a cross-sectional view of the permanent magnet motor 100 of the first embodiment viewed from a direction perpendicular to the axial direction, and FIG. 2 is a partially enlarged view of FIG. In this specification, in FIGS. 1 and 2, the clockwise direction is referred to as “one direction along the circumferential direction”, and the counterclockwise direction is referred to as “the other direction along the circumferential direction”. The same applies to each embodiment described below. Of course, the counterclockwise direction can also be referred to as “one direction” and the clockwise direction as “the other direction”.
In each embodiment, a 6-slot, 4-pole permanent magnet motor will be described. However, the number of slots and the number of poles of the permanent magnet motor of the present invention can be changed as appropriate.

The permanent magnet motor 100 of this embodiment includes a stator 110 and a rotor 120.
Stator 110 is constituted by a stator core in which a plurality of electromagnetic steel plates are laminated. The stator 110 has a yoke portion 111 extending along the circumferential direction and a teeth portion 112 extending from the yoke portion 111 in the radial center O direction when viewed in a cross section perpendicular to the axial direction. is doing. The teeth portion 112 includes a tooth base portion 112a extending in the radial direction from the yoke portion 111, and a tooth tip portion 112b provided on the tip side (rotation center O side) of the tooth base portion 112a and extending in the circumferential direction. have. A tooth tip surface 113 is formed on the rotation center O side of the tooth tip 112b. The tooth front end surface 113 forms an “inner peripheral surface of the stator 110”.
A stator winding (not shown) is inserted into a slot 114 formed by the teeth 112 adjacent in the circumferential direction. In the present embodiment, the stator winding is inserted into the slot 114 using a concentrated winding method. Of course, a distributed winding method can also be used.

The rotor 120 is constituted by a rotor core in which a plurality of electromagnetic steel plates are stacked. The rotor 120 has main magnetic pole portions [A] to [D] and auxiliary magnetic pole portions [AB] to [DA] arranged alternately along the circumferential direction when viewed in a cross section perpendicular to the axial direction. Magnet insertion portions 130 extending in the circumferential direction are formed in the main magnetic pole portions [A] to [D], and permanent magnets 140 are inserted into the magnet insertion portions 130.
The permanent magnets 140 inserted into the magnet insertion portions 130 of the main magnetic pole portions [A] to [D] are arranged so that the N-pole main magnetic pole portions and the S-pole main magnetic pole portions are alternately arranged along the circumferential direction. Magnetized. As a method for magnetizing the permanent magnet 140, a built-in magnetizing method in which a magnetizing current is passed through the stator winding in a state where the permanent magnet 140 is inserted into the magnet insertion portion 130 is used. Of course, a method of magnetizing the permanent magnet 140 before inserting it into the magnet insertion portion 130 can also be used.
Various permanent magnets can be used as the permanent magnet. For example, a ferrite magnet, a rare earth magnet, a neodymium magnet containing terbium or dysprosium, or the like can be used.
The rotor 120 has a rotation shaft insertion hole 122 into which a rotation shaft (not shown) is inserted.
Although not shown in FIG. 2, the rotor 120 has a caulking pin insertion hole 123 and a passage hole 124. The caulking pin insertion hole 123 is formed at a position intersecting the q axis, and caulking pins for integrating a plurality of laminated electromagnetic steel plates are inserted. The passage holes 124 are formed on both sides in the circumferential direction across the d axis, and a refrigerant used in the compressor, a cooling medium (for example, air) for cooling the stator 110 and the rotor 120, and the like flow along the axial direction. The shape, number, arrangement position, and the like of the caulking pin insertion hole 123 and the passage hole 124 can be changed as appropriate.

In the present embodiment, the magnet insertion portion 130 includes a linear first inner wall 130a and a second inner wall 130b, a first outer wall 130c and a second outer wall 130d that extend in parallel, and a first linear outer periphery. One magnet insertion hole formed by the wall 130e and the second outer peripheral wall 130g, the linear first end wall 130f and the second end wall 130h, the first protrusion 130x and the second protrusion 130y. It is configured. Hereinafter, it is referred to as “magnet insertion hole 130”.
The magnet insertion hole 130 has a central portion (a portion corresponding to the d-axis) along the circumferential direction protruding from the both end portions (the end portion on the q-axis side) to the outer peripheral side of the rotor 120 (hereinafter referred to as “in the outer peripheral side”). It is formed in a V-shape). That is, a linear first inner wall 130a and a first outer wall 130c, a first outer peripheral wall 130e, a first end wall 130f, and a first protrusion 130x extending in parallel on one side of the V shape. A straight second inner wall 130b and a second outer wall 130d, a second outer peripheral wall 130g, a second end wall 130h, and a second protrusion 130y are formed in a V shape. The other side is formed.
The first end wall 130f of the magnet insertion hole 130 extends in parallel with the second end wall 130h of the magnet insertion hole 130 of the adjacent main magnetic pole part.

The permanent magnet 140 includes a first permanent magnet piece 141 and a second permanent magnet piece 142 that are inserted into the magnet insertion hole 130. The first and second permanent magnet pieces 141 and 142 include linear inner walls 141a and 142a and outer walls 141b and 142b extending in parallel, linear first end walls 141c and 142c extending in parallel, and It has a quadrangular cross section formed by two end walls 141d and 142d.
The permanent magnet 140 is arranged in a V shape protruding to the outer peripheral side. That is, the first permanent magnet piece 141 is disposed along one V-shaped piece, and the second permanent magnet piece 142 is disposed along the other V-shaped side.

Between the outer peripheral wall (the first outer peripheral wall 130e and the second outer peripheral wall 130g) at both ends along the circumferential direction of the magnet insertion hole 130 and the outer peripheral surface 121 of the rotor 120, that is, the periphery of the permanent magnet 140 End walls at both ends along the direction (the second end wall 141d on the one side along the circumferential direction of the first permanent magnet piece 141 and the other side along the circumferential direction of the second permanent magnet piece 142) A first bridge portion 160a and a second bridge portion 160b are formed between the second end wall 142d) and the outer peripheral surface 121 of the rotor 120.
The strength against the centrifugal force of the rotor 120 is increased by the first bridge portion 160a and the second bridge portion 160b.

Further, both end portions of the magnet insertion hole 130 along the circumferential direction, that is, end walls of both ends of the permanent magnet 140 along the circumferential direction (on one side of the first permanent magnet piece 141 along the circumferential direction). The second end wall 141d and the second permanent magnet piece 142, the second end wall 142d on the other side along the circumferential direction, and the end walls (first side) of the magnet insertion portion 130 along the circumferential direction. The first space 150a and the second space 150b are formed between the end wall 130f and the second end wall 130h).
The first space 150a and the second space 150b allow the magnetic flux generated from the permanent magnet 140 to be generated at both ends along the circumferential direction of the permanent magnet 140 (hereinafter referred to as “the both ends of the permanent magnet 140”). A short circuit can be prevented.

In the present embodiment, the position of the permanent magnet 140 (the position of the first permanent magnet piece 141 and the second permanent magnet piece 142) can be set by the first protrusion 130x and the second protrusion 130y. . Thus, both end portions of the magnet insertion hole 130 (the second end wall 141d of the first permanent magnet piece 141 and the second end of the second permanent magnet piece 142 are changed without greatly changing the shape of the magnet insertion hole 130. The length along the circumferential direction of the first space 150a and the second space 150b formed between the end wall 142d and the first end wall 130f and the second end wall 130h of the magnet insertion hole 130). Can be easily changed. Therefore, a short circuit of magnetic flux at both ends of the permanent magnet 140 can be reliably prevented.
In the present embodiment, the first protrusion 130x and the second protrusion 130y correspond to the “positioning portion” of the present invention.

Further, the outer peripheral surface 121 of the rotor 120 intersects the first outer peripheral portion 121a that intersects the d axis of the main magnetic pole portions [A] to [D] and the q axis of the auxiliary magnetic pole portions [AB] to [DA]. The second outer peripheral portions 121b to be connected are alternately connected. The first outer peripheral portion 121a and the second outer peripheral portion 121b are connected by connection portions 120A and 120B.
The first outer peripheral portion 121a is formed in an arc shape having a radius R1 (projecting toward the outer peripheral side) with the rotation center O on the d axis as a center point. The second outer peripheral portion 121b is on the q axis and has a point P away from the rotation center O on the side opposite to the second outer peripheral portion 121b as a center point, and the arc shape of the first curved portion 121a. It is formed in a circular arc shape having a radius R2 larger than the radius R1 (projecting outwardly). In other words, the gap (air gap) between the inner peripheral surface (tooth tip surface 113) of the stator 110 and the outer peripheral surface 121 of the rotor 120 is such that the gap G2 along the q axis is larger than the gap G1 along the d axis. It is set to be large.
The outer peripheral surface 121 of the rotor 120 is alternately formed with a first outer peripheral portion 121a formed in an arc shape with a radius R1 and a second outer peripheral portion 121b formed in an arc shape with a radius R2 (radius R2> radius R1). By connecting and configuring, it is possible to reduce the change in the amount of magnetic flux in the connecting portions 120A and 120B between the first outer peripheral portion 121a and the second outer peripheral portion 121b, and to induce the induced voltage in the stator winding The harmonic component contained in the waveform (electromotive force waveform) can be reduced. As a result, when using a sensorless control type control device that detects the position of the rotor based on the electromotive force waveform without using the rotor position detection sensor, the efficiency decreases due to a decrease in the position detection accuracy of the rotor. Can be prevented.

In the first embodiment, the magnet insertion portion is formed in a protruding shape (permanent magnets are arranged in a protruding shape). Thereby, a magnet surface area increases and the amount of magnetic flux (effective magnetic flux amount) increases. And since the electric current which flows into a stator winding | coil can be made small by the amount of magnetic flux increasing, copper loss can be reduced.
In addition, the magnet insertion portion is formed in a protruding shape protruding to the outer peripheral side (the permanent magnet is arranged in a protruding shape protruding to the outer peripheral side). Thereby, the space | interval between the both ends along the circumferential direction of a permanent magnet and the outer peripheral surface of a rotor becomes small, and between the both ends of the said permanent magnet along the circumferential direction and the outer peripheral surface of a rotor. The reluctance torque generated by the magnetic flux passing through is reduced. By reducing the reluctance torque, the iron loss is reduced. On the other hand, since the distance between the permanent magnet and the outer peripheral surface of the rotor is reduced, the decrease in the amount of magnetic flux due to the armature reaction is greatly suppressed. Thereby, while being able to reduce an iron loss, the amount of magnetic flux (effective magnetic flux amount) can be increased and efficiency improves.
Furthermore, in 1st Embodiment, the magnet insertion part is formed in V shape (a permanent magnet is arrange | positioned in V shape). Thereby, the center part of the permanent magnet along the circumferential direction (when permanent magnet pieces are arranged on both sides of the d-axis, the end wall on the d-axis side of each magnet piece) and the outer peripheral surface of the rotor The interval between the two can be reduced. Accordingly, it is possible to further suppress a decrease in the effective magnetic flux amount due to the armature reaction.
Further, the outer peripheral surface of the rotor alternates between a first outer peripheral portion having an arc shape (radius R1) intersecting with the d axis and a second outer peripheral portion having an arc shape intersecting with the q axis (radius R2> radius R1). Connected to and configured. That is, the outer peripheral surface of the rotor is formed such that the gap G2 along the q axis is larger than the gap G1 along the d axis. As a result, the magnetic flux generated from both ends of the permanent magnet along the circumferential direction can easily flow to the first outer peripheral portion side where the gap interval is small (it is difficult to flow to the second outer peripheral portion side where the gap interval is large). The amount of magnetic flux in the main magnetic pole portion increases. Further, the magnetic flux generated by passing a current through the stator windings easily flows to the first outer peripheral portion where the gap interval is small (it becomes difficult to flow to the second outer peripheral portion where the gap interval is large), and the permanent magnet Can be prevented from demagnetizing due to magnetic flux concentration. In addition, since the harmonic component contained in the electromotive force waveform can be reduced, a control device (control based on the position of the rotor detected using the electromotive force waveform of the stator winding) of the sensorless control method is provided. When used, it is possible to prevent a decrease in efficiency due to a decrease in rotor position detection accuracy.
Moreover, since the positioning part which positions a permanent magnet is provided, the 1st space part and 2nd space part for preventing the magnetic flux short circuit in the both ends of a permanent magnet can be changed easily.
Therefore, the efficiency of the permanent magnet motor can be improved.

3 and 4 show a second embodiment of the permanent magnet motor of the present invention. FIG. 3 is a cross-sectional view of the permanent magnet motor 200 according to the second embodiment viewed from a direction perpendicular to the axial direction, and FIG. 4 is a partially enlarged view of FIG.
The permanent magnet motor 200 of the second embodiment is different from the permanent magnet motor 100 of the first embodiment in the configuration of the magnet insertion portion 230 and the permanent magnet 240. Therefore, below, the structure of the magnet insertion part 230 and the permanent magnet 240 of the permanent magnet electric motor 200 of 2nd Embodiment is demonstrated. 3 and 4, components other than the magnet insertion portion 230 and the permanent magnet 240 are denoted by the same reference numerals as those shown in FIGS. 1 and 2 except for the numbers in the hundreds. The components that are present are the same components.

In this embodiment, the magnet insertion part 230 is comprised by the 1st magnet insertion hole 231 and the 2nd magnet insertion hole 232 which are arrange | positioned along the circumferential direction. The first and second magnet insertion holes 231 and 232 include linear inner walls 231a and 232a and outer walls 231b and 232b, linear outer peripheral walls 231d and 232d, and linear first end walls 231c extending in parallel. And 232c, linear second end walls 231e and 232e, a first protrusion 231x, and a second protrusion 232y.
The magnet insertion part 230 is formed in a V shape protruding to the outer peripheral side. That is, the first magnet insertion hole 231 is formed along one side of the V shape, and the second magnet insertion hole 232 is formed along the other side of the V shape.
The first end wall 231c on the other side along the circumferential direction of the first magnet insertion hole 231 and the first end wall 232c on the one side along the circumferential direction of the second magnet insertion hole 232 are parallel to each other. It extends to. In addition, the second end wall 231e on the one side along the circumferential direction of the first magnet insertion hole 231 is formed on the other side along the circumferential direction of the second magnet insertion hole 232 of the adjacent main magnetic pole part. The second end wall 232e extends in parallel.

The permanent magnet 240 is constituted by first and second permanent magnet pieces 241 and 242 inserted into the first and second magnet insertion holes 231 and 232. As in the first embodiment, the first and second permanent magnet pieces 241 and 242 include inner walls 241a and 242a and outer walls 241b and 242b extending in parallel, first end wall 241c extending in parallel and It has a quadrangular cross section formed by 242c and second end walls 241d and 242d.
The permanent magnet 240 is arranged in a V shape protruding to the outer peripheral side. That is, the first permanent magnet piece 241 is arranged along one side of the V shape, and the second permanent magnet piece 242 is arranged along the other side of the V shape.

  The outer peripheral wall (the outer peripheral wall 231d of the first magnet insertion hole 231 and the outer peripheral wall 232d of the second magnet insertion hole 232) at both ends along the circumferential direction of the magnet insertion portion 230 and the outer peripheral surface 231 of the rotor 220. That is, the end walls of the permanent magnet 240 at both ends along the circumferential direction (the second end wall 241d and the second permanent magnet piece 242 on one side of the first permanent magnet piece 241 along the circumferential direction). The first bridge portion 260 a and the second bridge portion 260 b are formed between the second end wall 242 d on the other side in the circumferential direction and the outer peripheral surface 221 of the rotor 220. Further, a third bridge portion 260c is provided between the first magnet insertion hole 231 and the second magnet insertion hole 232 (between the first permanent magnet piece 241 and the second permanent magnet piece 242). Is formed. The strength with respect to the centrifugal force of the rotor 220 is further increased by the third bridge portion 260c.

Further, both end portions along the circumferential direction of the magnet insertion hole 230, that is, end walls at both ends along the circumferential direction of the permanent magnet 240 (the second end wall 241d of the first permanent magnet piece 241 and the second end wall 241d). The end walls (second end wall 231e of the first magnet insertion hole 231 and the second magnet insertion hole) at both ends along the circumferential direction of the second end wall 242d of the permanent magnet piece 242 and the magnet insertion portion 230. Between the second end wall 232e) of the 232, a first space 250a and a second space 250b for preventing a short circuit of magnetic flux at both ends of the permanent magnet 240 are formed.
In the present embodiment, the position of the permanent magnet 240 (the position of the first permanent magnet piece 241 and the second permanent magnet piece 242) can be set by the first protrusion 231x and the second protrusion 232y. . Thus, both ends of the magnet insertion hole 230 (the second end wall 241d of the first permanent magnet piece 241 and the second end of the second permanent magnet piece 242 can be obtained without greatly changing the shape of the magnet insertion hole 230. The first space 250a and the second space 242d formed between the end wall 242d and the second end wall 231e of the first magnet insertion hole 231 and the second end wall 232e of the second magnet insertion hole 232). The length of the space portion 250b along the circumferential direction can be easily changed. Therefore, a short circuit of magnetic flux at both ends of the permanent magnet 240 can be reliably prevented.

  In addition, the outer peripheral surface 221 of the rotor 220 has a first outer peripheral portion 221a formed in an arc shape (radius R1) intersecting with the d axis and an arc shape intersecting with the q axis, as in the first embodiment. The second outer peripheral portions 221b formed with (radius R2> radius R1) are alternately connected.

In the second embodiment, the magnet insertion portion is formed in a protruding shape protruding to the outer peripheral side (permanent magnets are arranged in a protruding shape). Thereby, a magnet surface area increases and the amount of magnetic flux (effective magnetic flux amount) increases. In addition, the distance between the end portions of the permanent magnet along the circumferential direction and the outer peripheral surface of the rotor is reduced, and the gap between the end portions of the permanent magnet along the circumferential direction and the outer peripheral surface of the rotor is reduced. The reluctance torque generated by the passing magnetic flux is reduced, and the iron loss generated due to the reluctance torque can be reduced. On the other hand, since the distance between the permanent magnet and the outer peripheral surface of the rotor is reduced, the decrease in the amount of magnetic flux due to the armature reaction is greatly suppressed. Thereby, while being able to reduce an iron loss, the amount of magnetic flux (effective magnetic flux amount) can be increased and efficiency improves.
Furthermore, in the second embodiment, since the magnet insertion portion is formed in a V shape (permanent magnets are arranged in a V shape), the center portion of the permanent magnet in the circumferential direction (on both sides of the d-axis). In the case where the permanent magnet pieces are arranged, the distance between each permanent magnet piece between the end wall on the d-axis side and the outer peripheral surface of the rotor can be reduced. Accordingly, it is possible to further suppress a decrease in the effective magnetic flux amount due to the armature reaction.
Moreover, the magnet insertion part is comprised by the several magnet insertion hole arrange | positioned along the circumferential direction via the bridge part (The permanent magnet is arrange | positioned along the circumferential direction via the bridge part. By being composed of a plurality of permanent magnet pieces), the strength of the rotor against centrifugal force is increased.
In addition, the outer peripheral surface of the rotor is a first outer peripheral portion formed in a circular arc shape (radius R1) intersecting with the d axis and a second circular arc shape intersecting the q axis (radius R2> radius R1). The outer peripheral portions are alternately connected.
Therefore, the efficiency of the permanent magnet motor can be improved.

The present invention can also be configured as follows.
(Aspect 1)
A stator and a rotor arranged in the stator via a gap; the rotor has a main magnetic pole portion and an auxiliary magnetic pole portion alternately along the circumferential direction when viewed in a cross section perpendicular to the axial direction; A permanent magnet motor in which a magnet insertion part is provided in the main magnetic pole part, and a permanent magnet is inserted in the magnet insertion part,
The magnet insertion portion is formed in a V shape in which a central portion along the circumferential direction protrudes from both end portions to the outer peripheral side of the rotor when viewed in a cross section perpendicular to the axial direction.
In the magnet insertion portion, the permanent magnet is formed such that a first space portion and a second space portion are formed at one end and the other end in the circumferential direction of the magnet insertion portion. Positioning part is provided,
When the outer peripheral surface of the rotor is viewed in a cross section perpendicular to the axial direction, the gap interval along the q axis of the auxiliary magnetic pole portion is longer than the gap interval along the d axis of the main magnetic pole portion. A permanent magnet motor characterized by being formed.
(Aspect 2)
The permanent magnet electric motor according to aspect 1, wherein the magnet insertion portion includes a first magnet insertion hole and a second magnet insertion hole arranged on one side and the other side along the circumferential direction with the bridge portion interposed therebetween. The first space portion is formed at an end portion on the one side along the circumferential direction of the first magnet insertion hole, and along the circumferential direction of the second magnet insertion hole. The permanent magnet motor, wherein the second space is formed at an end of the other side .

The present invention is not limited to the configuration described in the embodiment, and various changes, additions, and deletions are possible.
As an aspect in which the permanent magnet is arranged in a V shape or an aspect in which the magnet insertion portion is formed in a V shape, the permanent magnet is generally arranged in a V shape or the magnet insertion portion is formed in a V shape. Good.
In the embodiment, the magnet insertion hole is formed in the main magnetic pole portion, and the permanent magnet is inserted into the magnet insertion hole. However, the aspect of disposing the permanent magnet is not limited to this. For example, the aspect which arrange | positions a permanent magnet to a rotor by adhesion | attachment, integral molding, etc. can also be used. In other words, the present invention can also be configured as a permanent magnet electric motor, “permanent magnets are arranged in a V shape protruding to the outer peripheral side”.
The number and shape of the magnet insertion holes constituting the magnet insertion part of the main magnetic pole part can be changed as appropriate.
The number and shape of the permanent magnet pieces constituting the permanent magnet disposed in the main magnetic pole portion can be appropriately changed.
The shape and number of positioning portions for positioning the permanent magnet can be changed as appropriate.
The outer peripheral surface of the rotor can be formed in various shapes in which the gap G2 along the q axis is larger than the gap G1 along the d axis.
The permanent magnet motor of the present invention can be used as an electric motor for driving various devices.

100, 200 Permanent magnet motor 110, 210 Stator 111, 211 Yoke portion 112, 212 Teeth portion 112a, 212a Teeth base portion 112b, 212b Teeth tip portion 113, 213 Teeth tip surface 114, 214 Slot 120, 220 Rotor 121, 221 Outer peripheral surface 121a, 221a First outer peripheral portion 121b, 221b Second outer peripheral portion 121A, 121B, 221A, 221B Connection portion 122, 222 Rotating shaft insertion hole 123, 223 Caulking pin insertion hole 124, 224 Passage hole 130, 230 Magnet insertion Part 130a, 130b, 231a, 232a inner wall 130d, 130e, 231b, 232b outer wall 130e, 130g, 231d, 232d outer wall 130f, 130h, 231c, 231e, 232c, 232e end wall 140, 40 Permanent magnets 141, 142, 241, 242 Permanent magnet pieces 141a, 142a, 241a, 242a Inner walls 141b, 142b, 241b, 242b Outer walls 141c, 141d, 142c, 142d, 241c, 241d, 242c, 242d End walls 150a, 150b, 250a, 250b Space portions 160a, 160b, 260a, 260b, 260c Bridge portions 231, 232 Magnet insertion holes [A] to [D] Main magnetic pole portions [AB] to [DA] Auxiliary magnetic pole portions

Claims (4)

A stator and a rotor arranged in the stator via a gap; the rotor has a main magnetic pole portion and an auxiliary magnetic pole portion alternately along the circumferential direction when viewed in a cross section perpendicular to the axial direction; A permanent magnet motor in which a magnet insertion part is provided in the main magnetic pole part, and a permanent magnet is inserted in the magnet insertion part,
The magnet insertion portion is constituted by a magnet insertion hole formed in a V shape in which a central portion along the circumferential direction protrudes from both end portions to the outer peripheral side of the rotor when viewed in a cross section perpendicular to the axial direction. And
The magnet insertion hole includes a linear first inner wall and a first outer wall extending in parallel, a linear second inner wall and a second outer wall extending in parallel, and a linear first outer peripheral wall. And a second outer peripheral wall, a linear first end wall and a second end wall,
One side of the V-shape is formed by the first inner wall, the first outer wall, the first outer peripheral wall, and the first end wall,
The second side wall of the V shape is formed by the second inner wall, the second outer wall, the second outer peripheral wall, and the second end wall,
The first end wall extends in parallel with the second end wall of the adjacent main magnetic pole portion;
The permanent magnet is inserted into a first permanent magnet piece inserted into one side of the V-shape of the magnet insertion hole, and a first piece inserted into the other side of the V-shape of the magnet insertion hole. 2 permanent magnet pieces,
The first permanent magnet piece and the second permanent magnet piece have a linear inner wall and an outer wall extending in parallel, a linear end wall on one side, and an end wall on the other side,
The first space portion is formed in the magnet insertion hole between the one end wall of the first permanent magnet piece and the first end wall of the magnet insertion hole. A first space for positioning one permanent magnet piece, and a second space between the other end wall of the second permanent magnet piece and the second end wall of the magnet insertion hole. A second positioning part for positioning the second permanent magnet piece is provided so that
When the outer peripheral surface of the rotor is viewed in a cross section perpendicular to the axial direction, the gap interval along the q axis of the auxiliary magnetic pole portion is longer than the gap interval along the d axis of the main magnetic pole portion. A permanent magnet motor characterized by being formed. A stator and a rotor arranged in the stator via a gap; the rotor has a main magnetic pole portion and an auxiliary magnetic pole portion alternately along the circumferential direction when viewed in a cross section perpendicular to the axial direction; A permanent magnet motor in which a magnet insertion part is provided in the main magnetic pole part, and a permanent magnet is inserted in the magnet insertion part,
The magnet insertion portion is seen on a cross section perpendicular to the axial direction, on one side and the other side along the circumferential direction across the bridge portion, and the central portion along the circumferential direction is on the outer peripheral side of the rotor from both ends. Are constituted by a first magnet insertion hole and a second magnet insertion hole arranged in a V-shape protruding to
  The first magnet insertion hole and the second magnet insertion hole include a linear inner wall and an outer wall extending in parallel, a linear outer peripheral wall, a linear end wall on one side, and an end wall on the other side. Have
One side of the V shape is formed by the first magnet insertion hole,
The side of the other side of the V shape is formed by the second magnet insertion hole,
The one end wall of the first magnet insertion hole extends in parallel with the other end wall of the second magnet insertion hole of the adjacent main magnetic pole part,
The permanent magnet is composed of a first permanent magnet piece inserted into the first magnet insertion hole and a second permanent magnet piece inserted into the second magnet insertion hole,
The first permanent magnet piece and the second permanent magnet piece have a linear inner wall and an outer wall extending in parallel, a linear end wall on one side, and an end wall on the other side,
A first space portion is formed in the first magnet insertion hole between the one end wall of the first permanent magnet piece and the one end wall of the first magnet insertion hole. A first positioning portion for positioning the first permanent magnet piece is provided,
In the second magnet insertion hole, a second space is formed between the other end wall of the second permanent magnet piece and the other end wall of the second magnet insertion hole. A second positioning portion for positioning the second permanent magnet piece is provided,
When the outer peripheral surface of the rotor is viewed in a cross section perpendicular to the axial direction, the gap interval along the q axis of the auxiliary magnetic pole portion is longer than the gap interval along the d axis of the main magnetic pole portion. A permanent magnet motor characterized by being formed. The permanent magnet motor according to claim 1 or 2 ,
The outer peripheral surface of the rotor is formed by alternately connecting a first outer peripheral portion that intersects the d-axis of the main magnetic pole portion and a second outer peripheral portion that intersects the q-axis of the auxiliary magnetic pole portion. The first outer peripheral portion is formed in an arc shape having a center point on the d-axis, and the second outer peripheral portion has a center point on the q-axis, and is smaller than the radius of the first outer peripheral portion. A permanent magnet motor characterized by being formed in an arc shape having a large radius. It is an apparatus drive apparatus provided with the electric motor which drives an apparatus and the said apparatus, Comprising: The permanent magnet electric motor as described in any one of Claims 1-3 is used as the said electric motor, The apparatus characterized by the above-mentioned. Drive device.

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