WO2016021651A1 - Motor - Google Patents

Abstract

The present invention achieves a motor capable of efficiently improving reluctance torque. Slits (40, 42, 44) are formed for each magnetic pole in a rotor core (34) of a motor (10). Outer-circumferential bridge sections (50, 52, 54) are formed between the outer-circumferential section of the rotor core (34) and the end sections of the slits (40, 42, 44) on the rotor-core (34) outer-circumferential side thereof. Notches (60, 62, 64) are formed in the outer-circumferential bridge sections (50, 52, 54) so as to extend from the outer-circumferential side toward the inner-circumferential side. As a result, magnetic permeability is low and magnetic field strength is high in the spaces formed in the outer-circumferential bridge sections (50, 52, 54) by the notches (60, 62, 64) of the outer-circumferential bridge sections (50, 52, 54), and through which magnetic flux flows in the circumferential direction of the rotor core (34). As a result, it is possible to efficiently improve reluctance torque, because a circumferential direction component of the magnetic force of the rotor core (34) is significantly produced by the reverse-rotation-direction-side boundary of the notches (60, 62, 64).

Description

motor

The present invention relates to a motor that uses reluctance torque.

Conventionally, there are the following Patent Documents 1 and 2 as motors that use reluctance torque (the force that a coil attracts iron). In Patent Document 1, by providing a barrier space for preventing magnetic flux short circuit on the outer peripheral side of the rotor core, the magnetic flux flowing from the stator to the portion between the magnetic poles flows to the portion between the magnetic poles of the adjacent pole via the rotor outer peripheral portion. The reluctance torque is improved by reducing the inductance in the direction of the magnetic flux generated by the magnetic pole (d-axis). Further, in Patent Document 2, since the magnetic resistance of the leakage magnetic path is increased and the d-axis magnetic resistance is increased by providing the second window for preventing magnetic flux short-circuiting on the outer periphery, the d-axis and the d-axis are electrically connected. The reluctance torque is improved by increasing the magnetoresistive difference from the magnetically orthogonal q axis.

JP2013-236418A Japanese Patent Laid-Open No. 2001-21618

However, in Patent Document 1, when the barrier space is provided, the radial component of the magnetic flux flowing from the circumferential surface of the portion between the magnetic poles to the stator increases, and the electromagnetic force also increases in the ratio of the radial component. For this reason, the electromagnetic force of the circumferential direction component which generates rotational torque does not improve efficiently. Further, in Patent Document 2, since the second window is on a belt-like portion that is a q-axis magnetic path, if the second window is disposed in order to increase the d-axis magnetic resistance, the q-axis magnetic resistance also increases and the reluctance torque is increased. Does not improve efficiently.

The present invention has been made in view of the above facts, and an object of the present invention is to obtain a motor that can efficiently improve the reluctance torque.

The motor of the first aspect of the present invention is a slit formed in each magnetic pole of the rotor core, an outer peripheral bridge portion formed between the outer peripheral portion of the rotor core and the end portion on the outer peripheral portion side of the slit, A notch formed in the outer peripheral bridge portion from the outer peripheral side toward the inner peripheral side, and a thin plate portion formed by compression processing on a part of the outer peripheral bridge portion and having a smaller thickness than other portions of the outer peripheral bridge portion; And at least one of the following.

In the first aspect, the magnetic flux flowing in the rotor core of the motor flows out to the stator via the outer peripheral bridge portion formed between the outer peripheral portion of the rotor core and the end portion on the outer peripheral portion side of the rotor core in the slit. . As a result, magnetic flux flows in the circumferential direction of the rotor core through the outer bridge portion. Therefore, if at least one of the notch from the outer peripheral side to the inner peripheral side is provided in the outer peripheral bridge part and a thin plate part thinner than other parts of the outer peripheral bridge part by compression processing is provided in a part of the outer peripheral bridge part. In the space formed by the provision, the magnetic permeability is low and the strength of the magnetic field is large. For this reason, the direction of the electromagnetic force of the rotor core is inclined in the circumferential direction, and the circumferential direction component of the electromagnetic force of the rotor core is greatly generated by the notch or the counter-rotation direction side boundary of the thin plate portion, and the reluctance torque in the rotation direction is efficiently generated. Can be improved. As a result, the rotational torque of the rotor core is improved. Further, as the circumferential component of the electromagnetic force increases, the radial electromagnetic force component to the stator decreases. For this reason, vibration noise can be reduced by suppressing vibration in the radial direction of the stator, which is the cause of vibration and noise. Moreover, the strength of the rotor core can be ensured by providing the thin plate portion with improved yield stress by forming the compression plate at a part of the outer bridge portion.

According to a second aspect of the present invention, in the motor according to the first aspect, a permanent magnet is mounted inside the slit.

In the second aspect, the magnetic flux flowing in the rotor core of the motor is the outer bridge portion formed between the outer periphery of the rotor core and the end on the outer periphery side of the rotor core in the slit in which the permanent magnet is mounted. Flows out to the stator. As a result, magnetic flux flows in the circumferential direction of the rotor core through the outer bridge portion. Therefore, at least a notch formed in the outer peripheral bridge portion from the outer peripheral side toward the inner peripheral side, and a thin plate portion that is thinner than other portions of the outer peripheral bridge portion by compression processing on a part of the outer peripheral bridge portion. When one is provided, the magnetic permeability is low and the strength of the magnetic field is increased in the space formed by the provision. For this reason, the direction of the electromagnetic force of the rotor core is inclined in the circumferential direction, and the circumferential direction component of the electromagnetic force of the rotor core is greatly generated by the notch or the counter-rotation direction side boundary of the thin plate portion, and the reluctance torque in the rotation direction is efficiently generated. Can be improved. As a result, the rotational torque of the rotor core is improved. Further, as the circumferential component of the electromagnetic force increases, the radial electromagnetic force component to the stator decreases. For this reason, vibration noise can be reduced by suppressing vibration in the radial direction of the stator, which is the cause of vibration and noise. Moreover, the strength of the rotor core can be ensured by providing the thin plate portion with improved yield stress in a part of the outer bridge portion.

According to a third aspect of the present invention, in the motor of the first aspect or the second aspect, the notch or the thin plate portion is formed on the outer circumferential bridge portion on the opposite side to the rotation direction of the rotor core.

In the third aspect, since the notch or the thin plate portion is formed on the opposite side to the rotation direction of the rotor core in the outer peripheral bridge portion that becomes the path of the magnetic flux flowing through the rotor core, the reluctance torque can be improved more efficiently.

According to a fourth aspect of the present invention, in the motor according to any one of the first to third aspects, the notch or the thin plate portion is disposed asymmetrically with respect to the magnetic pole center.

In the fourth aspect, since the notch or the thin plate portion is arranged asymmetrically with respect to the magnetic pole center, the notch or the thin plate portion can be arranged with reference to a predetermined rotation direction. As a result, the reluctance torque can be improved more efficiently.

According to a fifth aspect of the present invention, in the motor according to any one of the first to fourth aspects, the depth of the notch along the radial direction of the rotor core is 0 of the gap between the rotor core and the stator core. The length of the notch along the rotational direction of the rotor core is 1/6 to 2/3 of the length of the outer peripheral bridge portion.

In the fifth aspect, the depth of the notch along the radial direction of the rotor core is not less than 0.5 times the gap between the rotor core and the stator core and smaller than the width of the outer bridge portion. Further, the length of the notch along the rotation direction of the rotor core is 1/6 to 2/3 of the length of the outer peripheral bridge portion. For this reason, reluctance torque can be improved more efficiently.

According to a sixth aspect of the present invention, in the motor according to any one of the first to fourth aspects, the thickness of the thin plate portion is 50 to 86 of the thickness of the other portion of the outer peripheral bridge portion. %.

In the sixth aspect, since the thickness of the thin plate portion is 50 to 86% of the thickness of the other portion of the outer peripheral bridge portion, the reluctance torque can be improved more efficiently.

As described above, in the motor according to the present invention, the reluctance torque can be improved efficiently.

It is the schematic sectional drawing cut | disconnected in the direction orthogonal to the rotating shaft of the motor which concerns on 1st Embodiment of this invention. It is an expanded sectional view showing magnetic flux (PHI) and electromagnetic force F of a motor concerning a 1st embodiment of the present invention. It is an expanded sectional view corresponding to Drawing 2 concerning a 2nd embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view taken along a line 4-4 in FIG. It is an expanded sectional view corresponding to Drawing 2 concerning a 3rd embodiment of the present invention. It is the schematic sectional drawing cut | disconnected in the direction orthogonal to the rotating shaft of the motor which concerns on 4th Embodiment of this invention. It is an expanded sectional view corresponding to Drawing 2 concerning a 5th embodiment of the present invention. It is an expanded sectional view corresponding to Drawing 2 concerning a 6th embodiment of the present invention. It is an expanded sectional view corresponding to Drawing 2 concerning a 7th embodiment of the present invention. The relationship between the ratio (L2 / L1) of the notch length L2 with respect to the length L1 of an outer periphery bridge part and the increase rate of a reluctance torque by the difference in the notch depth D1 which concerns on 1st Embodiment of this invention is shown. It is a graph. When the length L3 of the arrangement range of the thin plate portion according to the second embodiment of the present invention is 83.3% of the length L1 of the outer peripheral bridge portion from the end surface in the counter-rotating direction, the outer peripheral bridge having the thickness M1 of the thin plate portion It is a graph which shows the relationship between the ratio (M1 / M) with respect to plate | board thickness M of the other site | part of a part, and the increase rate of a reluctance torque. The graph which shows the relationship between the ratio (L3 / L1) of the length L3 of a thin plate part with respect to the length L1 of an outer periphery bridge | bridging part, and the increase rate of a reluctance torque when M1 / M which concerns on 2nd Embodiment of this invention is constant. It is.

(First embodiment)
Hereinafter, the motor according to the first embodiment of the present invention will be described with reference to FIGS. 1, 2, and 10.

(Motor configuration)
As shown in FIG. 1, the motor 10 of this embodiment is a so-called IPM motor (permanent magnet synchronous motor) in which a permanent magnet 14 is embedded in a rotor 12. The motor 10 is a vehicle drive motor including a drive shaft 16. In the following, the axial direction refers to the rotational axis direction of the motor 10 (the direction of the axis Q1 of the drive shaft 16), and the radial direction refers to the radial direction orthogonal to the axis Q1. Further, the outer peripheral side refers to the radially outer side farther from the axis Q1, and the inner peripheral side refers to the radially inner side closer to the axis Q1.

<Structure of stator>
The stator 20 of the motor 10 includes a cylindrical stator core 22 and a coil (not shown). The stator core 22 is a laminated core obtained by punching an electromagnetic steel sheet by press working to create a planar laminated plate and laminating a large number of laminated plates in the axial direction. The stator core 22 includes a single back yoke portion 26, a plurality of teeth portions 28, and a flange portion 30.

The back yoke portion 26 is an annular portion formed on the outer peripheral portion of the stator core 22, and the outer periphery of the back yoke portion 26 is fixed to the inner surface of the casing 18. The teeth portion 28 is a portion formed in a rectangular parallelepiped shape extending radially inward from the inner peripheral surface of the back yoke portion 26. Between each tooth part 28, the coil slot 32 in which a coil (illustration omitted) is accommodated is formed. Each tooth portion 28 is wound with a coil (not shown), and the wound coil is accommodated in the coil slot 32. Thereby, an electromagnet is formed in each tooth portion 28. On the other hand, the brim portion 30 is formed continuously on the inner peripheral side of each tooth portion 28. Further, the brim portion 30 is configured to have a width (a length in the circumferential direction) larger than that of the tooth portion 28, and the inner circumferential surface is formed in a cylindrical shape. The cylindrical surface of the flange portion 30 is opposed to the outer peripheral surface (cylindrical surface) of the rotor 12 with a predetermined gap (air gap) G1.

<Rotor structure>
The rotor 12 of the motor 10 includes a rotor core 34 and a plurality of permanent magnets 14 and has a cylindrical shape. Further, the rotor 12 generates a magnet torque by the permanent magnet 14 and also generates a reluctance torque by the rotor core 34. In the present embodiment, six magnetic poles are formed in the rotor 12, and the permanent magnets 14 are provided in each magnetic pole so as to form a multilayer (three layers in the present embodiment) in the radial direction. Further, each permanent magnet 14 is formed in a circular arc shape having a convex inner peripheral side when viewed from the axial direction of the motor 10, and the permanent magnet 14 on the outer peripheral side has a shorter length (arc length).

(Structure of rotor core)
The rotor core 34 is a laminated core obtained by punching a magnetic steel sheet by press working to create a planar laminated plate and laminating a large number of laminated plates in the axial direction, and a hole 46 for attaching the drive shaft 16 to the center of the rotor core 34. Is formed.

In the rotor core 34, three slits (openings) 40, 42, 44 are formed at intervals in the radial direction for each magnetic pole. Each of the slits (openings) 40, 42, 44 is formed in an arc shape that is convex on the inner peripheral side when viewed from the axial direction of the motor 10, and the length (arc length) of the slit on the outer peripheral side becomes smaller. ing. In the present embodiment, these slits 40, 42, 44 are magnet slots into which the permanent magnets 14 are respectively attached, and the permanent magnets 14 are located in the longitudinal center portions of the slits 40, 42, 44. Is provided. In addition, the slits 40, 42, 44 of each magnetic pole are arranged at 60 ° pitch positions in the circumferential direction (around the axis) of the rotor core 34. Further, the slits 40, 42, 44 are formed in a substantially circular arc shape having a convex inner peripheral side when viewed from the axial direction of the motor 10, and penetrate the rotor core 34 in the axial direction of the motor 10.

The outer peripheral side portion and the inner peripheral side portion of the slits 40, 42, 44 in the rotor core 34 are connected by a pair of bridge portions 48, respectively. Each bridge portion 48 determines the size (length) of the permanent magnet 14, and the position of the bridge portion 48 is determined so that the end portion of the permanent magnet 14 and the bridge portion 48 are in contact with each other. Thus, if the magnet material is injected between the pair of bridge portions 48 in the slits 40, 42, 44, the size of the permanent magnet 14 can be defined by the bridge portion 48. In addition, a space is formed on the outer peripheral side of the bridge portion 48 in the slits 40, 42, and 44, and this space functions as a flux barrier 40A, 42A, and 44A (barrier space) for preventing a magnetic flux short circuit. Yes.

As shown in FIG. 1 and FIG. 2, an outer peripheral bridge portion 50 is provided between the outer peripheral portion of the rotor core 34 and the end portions on the outer peripheral portion side of the rotor core 34 in the flux barriers 40A, 42A, 44A of the slits 40, 42, 44. , 52, 54 are formed. Further, each outer bridge portion 50, 52, 54 (rotor core 34) and the flange portion 30 of the stator core 22 are opposed to each other with a gap G1.

The notches 60, 62, 64 are formed in the outer peripheral bridge portions 50, 52, 54 from the outer peripheral side toward the inner peripheral side, and the notches 60, 62, 64 are rectangular. Further, the notches 60, 62, 64 are formed at portions of the outer peripheral bridge portions 50, 52, 54 opposite to the rotation direction of the rotor core 34 (direction of arrow A in FIGS. 1 and 2). Further, the notches 60, 62, 64 are arranged asymmetrically with respect to the magnetic pole center P1. A line connecting the magnetic pole center P1 and the axis Q1 of the rotor core 34 is a magnetic pole center line H1.

In this embodiment, the width W1 along the radial direction of the rotor core 34 of each outer peripheral bridge portion 50, 52, 54 is equal to or larger than the gap G1, and along the circumferential direction of the rotor core 34 of each outer peripheral bridge portion 50, 52, 54. The length L1 (= flux barrier width) is not less than three times the gap G1. On the other hand, the depth D1 (the farthest edge portion distance from the outer circumference of the rotor core 34) of each notch 60, 62, 64 is 0.5 times or more of the gap G1 and smaller than the width W1 of the outer bridge portion. Further, the length L2 of the notches 60, 62, 64 along the circumferential direction of the rotor core 34 (the distance between the intersection points of the outer circumference circle of the rotor core 34 and the notch contour) is the length of the outer bridge portions 50, 52, 54. 1/6 to 2/3 of L1.

Further, the ratio (L2 / L1) of the length L2 of each notch 60, 62, 64 to the length L1 of each outer bridge portion 50, 52, 54 due to the difference in the depth D1 of each notch 60, 62, 64. The relationship with the increasing rate of the reluctance torque is as shown in FIG. For this reason, the arrangement range of each notch 60, 62, 64 is the depth D1 of each notch 60, 62, 64 and each notch 60, 62, 64 with respect to the length L1 of each outer periphery bridge | bridging part 50, 52, 54. It depends on the ratio of the length L2 (L2 / L1).

Therefore, when the depth D1 of each notch 60, 62, 64 is 0.5 times or more and less than 1 time of the gap G1, if the ratio L2 / L1 is 1/6 or more and less than 1/3, each notch 60, 62 , 64 is set to a range of ½ of the length L1 of each outer peripheral bridge portion 50, 52, 54 from the end surface in the counter-rotating direction. On the other hand, when the ratio L2 / L1 is not less than 1/3 and not more than 1/2, the arrangement range of the notches 60, 62, 64 is set to 1/3 of the length L1 of the outer peripheral bridge portions 50, 52, 54 from the end surface in the counter rotation direction. The range.

Further, when the depth D1 of each notch 60, 62, 64 is 1 time or more and less than 1.5 times the gap G1, when the ratio L2 / L1 is 1/6 or more and less than 1/3, each notch 60, 62 , 64 is set to a range of 5/6 of the length L1 of each outer peripheral bridge portion 50, 52, 54 from the end surface in the counter-rotating direction. On the other hand, when the ratio L2 / L1 is not less than 1/3 and less than 1/2, the arrangement range of the notches 60, 62, 64 is set to 2/3 of the length L1 of the outer peripheral bridge portions 50, 52, 54 from the counter-rotation direction end face. The range. Further, when the ratio L2 / L1 is 1/2 or more and 2/3 or less, the arrangement range of the notches 60, 62, 64 is set to 1/2 of the length L1 of the outer peripheral bridge portions 50, 52, 54 from the end surface in the counter rotation direction. The range.

When the depth D1 of each notch 60, 62, 64 is 1.5 times or more of the gap G1, the ratio L2 / L1 is not less than 1/6 and less than 1/2. The arrangement range is the entire range of each of the outer peripheral bridge portions 50, 52, and 54. On the other hand, when the ratio L2 / L1 is ½ or more and 2/3 or less , the arrangement range of the notches 60, 62, 64 is set to 5/6 of the length L1 of the outer peripheral bridge portions 50, 52, 54 from the counter-rotation direction end face. The range.

(Action and effect)
Next, the operation and effect of this embodiment will be described.

In the motor 10 of this embodiment, the magnetic flux Φ flowing through the rotor core 34 of the rotor 12 flows out to the stator 20 via the outer peripheral bridge portions 50, 52, 54 formed on the outer peripheral portion of the rotor core 34. As a result, the magnetic flux Φ flows in the circumferential direction of the rotor core 34 through the outer bridge portions 50, 52 and 54. Accordingly, when the outer bridge portions 50, 52, 54 are provided with the notches 60, 62, 64 from the outer periphery side toward the inner periphery side, the permeability formed by the notches 60, 62, 64 is low, and the magnetic field An electromagnetic force is generated in the direction in which the magnetic flux flows at the boundary where the strength increases and the magnetic field changes greatly.

For this reason, the direction of the electromagnetic force (arrow F in FIG. 2) of the rotor core 34 is inclined in the circumferential direction, and the circumferential component of the electromagnetic force F is greatly generated by the counter-rotation direction side boundaries of the notches 60, 62, and 64. As a result, the reluctance torque in the rotation direction of the rotor core 34 can be efficiently improved, and the rotation torque of the rotor core 34 is improved.

Further, as the circumferential component of the electromagnetic force F of the rotor core 34 is improved, the radial component of the electromagnetic force F from the rotor core 34 to the stator 20 is reduced. For this reason, vibration noise can be reduced by suppressing the vibration in the radial direction of the stator 20 that is the cause of vibration and noise.

Further, in the present embodiment, notches 60, 62, on the opposite side of the rotation direction of the rotor core 34 (direction of the arrow A in FIGS. 1 and 2) in the outer peripheral bridge portions 50, 52, and 54 serving as a path of the magnetic flux Φ flowing through the rotor core 34. 64 is formed. For this reason, reluctance torque can be improved more efficiently.

In the present embodiment, since the notches 60, 62, 64 are asymmetrically arranged with respect to the magnetic pole center P1, the notches 60, 62, 64 are arranged in a predetermined rotation direction (the direction of arrow A in FIGS. 1 and 2). ) As a reference. As a result, the reluctance torque can be improved more efficiently.

Further, in this embodiment, the width W1 along the radial direction of the rotor core 34 of each of the outer peripheral bridge portions 50, 52, 54 is not less than the gap G1, and the length L1 is not less than three times the gap G1. On the other hand, the depth D1 of each notch 60, 62, 64 is 0.5 times or more of the gap G1, and is smaller than the width W1 of the outer bridge portions 50, 52, 54. Further, the length L2 of each notch 60, 62, 64 is 1/6 to 2/3 of the bridge length L1, and the arrangement range of each notch 60, 62, 64 is that of each notch 60, 62, 64. This depends on the depth D1 and the ratio (L2 / L1) of the length L2 of each notch 60, 62, 64 to the length L1 of each outer bridge portion 50, 52, 54. For this reason, reluctance torque can be improved more efficiently.

(Second Embodiment)
Hereinafter, the motor according to the second embodiment of the present invention will be described with reference to FIGS. 3 and 4.
In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
As shown in FIG. 3, in this embodiment, instead of the notches 60, 62, 64 of the first embodiment, the outer bridge portions 50, 52, 54 are compressed by compressing the outer bridge portions 50, 52, 54. Thin plate portions 70, 72, and 74 that are thinner than other portions are formed. Further, the thin plate portions 70, 72, 74 are formed by compression processing, so that the yield stress increases due to work hardening, and the magnetic permeability decreases.

As shown in FIG. 4, the plate thickness M1 of the thin plate portions 70, 72, 74 is set to 50 to 86% of the plate thickness M of other portions. In the present embodiment, the thin plate portions 70, 72, 74 are configured to have recesses on both the front and back surfaces of the outer peripheral bridge portions 50, 52, 54. It is good also as a structure by which the recessed part is formed only in one side of the front and back of 52,54.

As shown in FIG. 3, the width D <b> 2 (the farthest edge portion distance from the outer circumferential circle of the rotor) of the arrangement range of the thin plate portions 70, 72, 74 is set in the entire width direction of the outer circumferential bridge portions 50, 52, 54. . Further, the length L3 of the arrangement range of the thin plate portions 70, 72, 74 is a range of 5/6 of the length L1 of each outer peripheral bridge portion 50, 52, 54 from the end surface in the counter-rotation direction.

For example, the length L3 of the arrangement range of the thin plate portions 70, 72, 74 is 83.3% (L3 / L1 = 83.3%) of the length L1 of the outer peripheral bridge portions 50, 52, 54 from the end surface in the counter rotation direction. In this case, the relationship between the ratio (M1 / M) of the plate thickness M1 of the thin plate portions 70, 72, 74 to the plate thickness M of the other portions of the outer bridge portions 50, 52, 54 and the increase rate of the reluctance torque is As shown in FIG.

Further, when M1 / M is constant, the ratio of the length L3 of the thin plate portions 70, 72, 74 to the length L1 of the outer peripheral bridge portions 50, 52, 54 (L3 / L1), the increase rate of the reluctance torque, The relationship is as shown in FIG.

(Action and effect)
Next, the operation and effect of this embodiment will be described.

In the motor 10 of this embodiment, the magnetic flux Φ flowing through the rotor core 34 of the rotor 12 flows out to the stator 20 via the outer peripheral bridge portions 50, 52, 54 formed on the outer peripheral portion of the rotor core 34. As a result, the magnetic flux Φ flows in the circumferential direction of the rotor core 34 through the outer bridge portions 50, 52 and 54. Therefore, when the thin plate portions 70, 72, 74 are provided on the outer peripheral bridge portions 50, 52, 54, in the space formed by the thin plate portions 70, 72, 74, the magnetic permeability is low and the magnetic field strength is increased. Electromagnetic force is generated in the direction in which the magnetic flux flows at a boundary where the value of the magnetic field changes greatly.

For this reason, the direction of the electromagnetic force F of the rotor core 34 is inclined in the circumferential direction, and the circumferential component of the electromagnetic force F is greatly generated by the counter-rotation direction side boundaries of the thin plate portions 70, 72, 74. As a result, the reluctance torque in the rotation direction of the rotor core 34 can be efficiently improved, and the rotation torque of the rotor core 34 is improved.

Further, as the circumferential component of the electromagnetic force F is improved, the radial component of the electromagnetic force F applied to the stator 20 is reduced. For this reason, vibration noise can be reduced by suppressing the vibration in the radial direction of the stator 20 that is the cause of vibration and noise.

In the present embodiment, the thin plate portions 70, 72, 74 are formed at the ends of the outer peripheral bridge portions 50, 52, 54 that are the path of the magnetic flux Φ flowing through the rotor core 34 on the opposite side to the rotation direction of the rotor core 34. In addition, the reluctance torque can be improved more efficiently.

In the present embodiment, since the thin plate portions 70, 72, and 74 are disposed asymmetrically with respect to the magnetic pole center P1, the thin plate portions 70, 72, and 74 are set in a predetermined rotation direction (the direction of arrow A in FIG. 3). It can be set as a reference. As a result, the reluctance torque can be improved more efficiently.

Further, in the present embodiment, since the thin plate portions 70, 72, 74 whose yield stress is increased by work hardening are provided in a part of the outer peripheral bridge portions 50, 52, 54, the strength of the rotor core 34 can be secured.

In the present embodiment, the plate thickness M1 of each of the thin plate portions 70, 72, 74 is set to 50 to 86% of the plate thickness M of other portions, and the width of the arrangement range of the thin plate portions 70, 72, 74 is set. D2 (the farthest edge portion distance from the rotor outer circumference circle) is set in the entire width direction of the outer circumference bridge sections 50, 52, and 54. Further, the length L3 of the thin plate portions 70, 72, and 74 is 5/6 or less of the length L1 of each of the outer peripheral bridge portions 50, 52, and 54. Each of the outer peripheral bridge portions 50, 52, 54 is in a range of 5/6 of the length L1. For this reason, reluctance torque can be improved more efficiently.

(Third embodiment)
Hereinafter, a motor according to a third embodiment of the present invention will be described with reference to FIG.
In addition, about the same member as 1st, 2 embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
As shown in FIG. 5, in this embodiment, in addition to the notches 60, 62, 64 of the first embodiment, the thin plate portions 70, 72, 74 of the second embodiment are formed.

Further, the arrangement of the thin plate portions 70, 72, 74 is set to the entire range (the entire circumferential direction) on the inner peripheral side of the portion where the notches 60, 62, 64 are formed in the outer peripheral bridge portions 50, 52, 54.

(Action and effect)
Next, the operation and effect of this embodiment will be described.

In the motor 10 of this embodiment, the magnetic flux Φ flowing through the rotor core 34 of the rotor 12 flows out to the stator 20 via the outer peripheral bridge portions 50, 52, 54 formed on the outer peripheral portion of the rotor core 34. As a result, the magnetic flux Φ flows in the circumferential direction of the rotor core 34 through the outer bridge portions 50, 52 and 54. Accordingly, in the space formed by the notches 60, 62, 64 and the thin plate portions 70, 72, 74 in the outer bridge portions 50, 52, 54, the magnetic permeability is low, the magnetic field strength is increased, and the magnetic field is greatly changed. At the boundary, electromagnetic force is generated in the direction in which the magnetic flux flows.

For this reason, the same effect as the first and second embodiments can be obtained. Further, the rotational torque and mechanical strength of the rotor core 34 are improved with respect to the first embodiment, and the rotational torque of the rotor core 34 is improved with respect to the second embodiment.
(Fourth embodiment)
Hereinafter, a motor according to a fourth embodiment of the present invention will be described with reference to FIG.
In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
As shown in FIG. 6, in the motor 78 of this embodiment, eight magnetic poles are formed in the rotor 12, and two slits (openings) 80 and 82 are formed in the rotor core 34 for each magnetic pole. . These slits 80 and 82 are slots for magnets to which the permanent magnets 14 are respectively attached, and the permanent magnets 14 are attached to intermediate portions in the longitudinal direction inside the respective slits 80 and 82. The slits 80 and 82 of each magnetic pole are arranged at a 45 ° pitch in the circumferential direction (around the axis) of the rotor core 34. The slits 80 and 82 are linear when viewed from the axial direction of the motor 10, and the slit 80 and the slit 82 are arranged in a substantially V shape with the inner peripheral side convex, and the rotor core 34 is arranged in the axial direction of the motor 10. It penetrates.

A space is formed on the outer peripheral side of the permanent magnets 14 in the slits 80 and 82, and this space functions as flux barriers 80A and 82A (barrier spaces) for preventing magnetic flux short circuits. Further, outer peripheral bridge portions 50 and 52 are formed between the outer peripheral portion of the rotor core 34 and the end portions on the outer peripheral portion side of the rotor core 34 in the flux barriers 80A and 82A of the slits 80 and 82, respectively. Further, similarly to the first embodiment, the outer peripheral bridge portions 50 and 52 are opposed to the stator core 22 with the gap G1.

Further, similarly to the first embodiment, notches 60 and 62 are formed in the outer peripheral bridge portions 50 and 52 from the outer peripheral side toward the inner peripheral side, and the notches 60 and 62 are rectangular. Yes. Further, the notches 60 and 62 are formed on the opposite sides of the rotation direction of the rotor core 34 (direction of arrow A in FIG. 6) in the outer peripheral bridge portions 50 and 52, respectively. The notches 60 and 62 are asymmetrically arranged with respect to the magnetic pole center P1.

(Action and effect)
Therefore, also in this embodiment, the same effect as the first embodiment can be obtained. Also in this embodiment, the thin plate portions 70 and 72 shown in the second embodiment may be provided in the respective outer bridge portions 50 and 52 in place of the notches 60 and 62, and as shown in the third embodiment. In addition, notches 60 and 62 and thin plate portions 70 and 72 may be provided in the outer peripheral bridge portions 50 and 52.

(Supplementary explanation of the embodiment)
In the first, third, and fourth embodiments, the notches 60, 62, and 64 are rectangular, but the notches 60, 62, and 64 are part of a circle as in the fifth embodiment shown in FIG. It is good also as a shape (semicircle shape etc.). Moreover, each notch 60,62,64 is good also as a triangular shape like 6th Embodiment shown in FIG. Moreover, it is good also as other shapes, such as trapezoid shape, notch 60, 62, 64 like 7th Embodiment shown in FIG.

In the above-described embodiment, a so-called IPM motor in which the permanent magnet 14 is embedded in the rotor 12 has been described. However, in the present invention, the rotor (rotor) is composed of only a ferromagnetic iron core, and is permanent. The present invention is also applicable to a synchronous reluctance motor that does not use a magnet. For example, in the first embodiment, the permanent magnets 14 may not be provided in the slits 40, 42, 44. Further, the number of slits of each magnetic pole is not limited to three in the first embodiment, and may be other plural or one.

In addition, the present invention can be implemented with various modifications without departing from the scope of the invention. It goes without saying that the scope of rights of the present invention is not limited to the above embodiment.

In addition, the disclosure of Japanese Patent Application No. 2014-160650, which is a Japanese application, is incorporated herein by reference in its entirety. In addition, all the documents, patent applications, and technical standards described in this specification are the same as when the individual documents, patent applications, and technical standards are specifically and individually described by reference. To the extent it is incorporated herein by reference.

DESCRIPTION OF SYMBOLS 10 Motor 12 Rotor 14 Permanent magnet 20 Stator 34 Rotor core 40 Slit 40A Flux barrier 42 Slit 42A Flux barrier 44 Slit 44A Flux barrier 50 Peripheral bridge part 60 Notch 62 Notch 64 Notch 70 Thin plate part 72 Thin plate part 74 Thin plate part 78 Motor 80 Flux barrier 82 Slit 82A Flux barrier

Claims (6)

Slits formed in each magnetic pole of the rotor core;
An outer peripheral bridge portion formed between an outer peripheral portion of the rotor core and an end portion on the outer peripheral portion side of the slit;
A notch formed in the outer peripheral bridge portion from the outer peripheral side toward the inner peripheral side, and a thin plate portion formed by compression processing on a part of the outer peripheral bridge portion and having a smaller thickness than other portions of the outer peripheral bridge portion; And at least one of
Having a motor. The motor according to claim 1, wherein a permanent magnet is mounted inside the slit. The motor according to claim 1 or 2, wherein the notch or the thin plate portion is formed on a side opposite to a rotation direction of the rotor core in the outer peripheral bridge portion. 4. The motor according to claim 1, wherein the notch or the thin plate portion is disposed asymmetrically with respect to a magnetic pole center. The depth of the notch along the radial direction of the rotor core is not less than 0.5 times the gap between the rotor core and the stator core and smaller than the width of the outer peripheral bridge portion, and the length of the notch along the rotation direction of the rotor core. 5. The motor according to claim 1, wherein is 1/6 to 2/3 of the length of the outer peripheral bridge portion. The motor according to any one of claims 1 to 4, wherein a thickness of the thin plate portion is 50 to 86% of a thickness of another portion of the outer peripheral bridge portion.

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