WO2015001601A1

WO2015001601A1 - Rotating electric machine and manufacturing method thereof

Info

Publication number: WO2015001601A1
Application number: PCT/JP2013/068032
Authority: WO
Inventors: 明仁中原; 菊地　聡; 和雄西濱; 秀俊江夏; 三好　努
Original assignee: 株式会社日立産機システム
Priority date: 2013-07-01
Filing date: 2013-07-01
Publication date: 2015-01-08
Also published as: JP6129966B2; CN105284038B; JPWO2015001601A1; CN105284038A

Abstract

Provided is a high-efficiency rotating electric machine which reduces loss due to harmonic flux. A radially inner rotor slot (4) and a radially outer rotor slot (6) are formed in the radial direction of the rotor core (2) with a radially inner bridge (7) therebetween. An arc-shape curved section (10) convex in the radially inward direction is formed on the radially outer shoulder portion of the radially outer rotor slot (6).

Description

Rotating electric machine and manufacturing method thereof

The present invention relates to a rotating electrical machine such as an induction motor having a cage rotor and a method for manufacturing the same.

A squirrel-cage rotor of a rotating electrical machine is formed of thin magnetic steel plates, and a plurality of rotor cores stacked in a thickness direction and a plurality of rotor slots formed in the circumferential direction of each rotor core are stacked. It is composed of a rotor conductor provided in series in each rotor slot of the rotor core. As a method of forming the rotor conductor, there are a method of inserting a copper bar into the rotor slot and a method of die casting a molten metal such as aluminum or an aluminum alloy in the rotor slot. In the case of the die casting method, in order to prevent the molten metal from leaking, unlike the case of the copper bar insertion method, an open slot cannot be formed in the rotor core, and the outer peripheral side end of the rotor slot is connected to the rotor core. It is necessary to form it inside from the outer periphery of and form a sealed shape.

For a rotating electrical machine having a cage rotor with a hermetic rotor slot formed, harmonic flux caused by the ripple current at the time of driving the stator slot or inverter is linked to the cage rotor so that the rotor It has been pointed out that eddy current loss occurs in the conductor, leading to a reduction in efficiency. Since the harmonic magnetic flux passes through the relatively outer periphery of the squirrel-cage rotor, it is desirable that the dimension from the outer peripheral side end of the rotor slot to the outer periphery of the core be as small as possible in order to suppress the reduction in efficiency. . However, since the rotor slot is formed by press punching, in order to form the rotor slot with high efficiency and high precision, a certain amount of space is formed between the outer peripheral end of the rotor slot and the outer periphery of the rotor core. There is no choice but to set an interval. Under these circumstances, various methods for improving the efficiency of this type of rotating electrical machine by other means have been proposed in place of reducing the distance from the outer peripheral end of the rotor slot to the outer periphery of the rotor core. ing.

For example, Japanese Patent Laid-Open No. 2002-315282 discloses a configuration in which an insulator is loaded on the outer peripheral side of the rotor slot to reduce the loss by reducing the amount of linkage between the rotor conductor and the harmonic magnetic flux. Has been. In JP-A-8-140319, two slots, an inner peripheral side slot and an outer peripheral side slot, are provided in the radial direction of the rotor core, the conductor is filled only in the inner peripheral side slot, and an eddy current generation site is defined. A configuration for reducing the loss by deleting is disclosed.

JP 2002-315282 A Japanese Patent Laid-Open No. 8-140319

However, according to the means disclosed in

Patent Documents

1 and 2, since the distance from the outer peripheral end of the rotor conductor to the outer periphery of the rotor core becomes large, The main magnetic flux as an output also passes through the outer peripheral side of the rotor conductor, and the amount of flux linkage to the rotor conductor may be reduced.

In addition, when the rotating electrical machine is driven as an induction motor, a magnetic field that rotates at a certain rotational speed from the stator acts on the rotor that does not rotate at the time of starting. Interlink with. However, in many cases, the harmonic magnetic flux at the start and the harmonic magnetic flux acting on the rotor during operation and causing loss are different in frequency. In this case, as in the techniques disclosed in

Patent Documents

1 and 2, if the method of reducing the interlinkage amount of the harmonic magnetic flux and the configuration in which the conductor itself is arranged on the inner peripheral side, the interlinkage magnetic flux at the start is also the conductor As a result, the magnetic flux itself interlinked with the magnetic flux decreases, and there is a possibility that sufficient torque cannot be obtained at the time of starting.

The present invention has been made in order to solve such a problem of conventional typography, and the object of the present invention is to provide a rotating electrical machine that reduces loss due to harmonic magnetic flux and improves efficiency. There is. It is another object of the present invention to provide a rotating electrical machine that prevents leakage of main magnetic flux and does not impair torque, and improves efficiency during operation. Furthermore, it is providing the method of manufacturing such a rotary electric machine efficiently.

In order to solve the above problems, the present invention relates to a rotating electrical machine, and includes a stator and a rotor rotatably disposed in the stator, and the rotor is a laminate of a plurality of thin magnetic steel plates. A rotor core consisting of: an inner diameter side rotor slot and an outer diameter side rotor slot of a sealed structure formed in the rotor core; an inner diameter side rotor conductor formed in the inner diameter side rotor slot; and It has a double cage structure with an outer diameter side rotor conductor formed in an outer diameter side rotor slot, and the outer diameter side rotor slot protrudes in the inner diameter direction on the left and right shoulders on the outer diameter side. It has a characteristic arcuate curved portion.

In addition, regarding the method of manufacturing the rotating electrical machine, a step of forming a predetermined number of thin magnetic steel plates having an inner diameter side rotor slot and an outer diameter side rotor slot, and an inner diameter side rotor slot and an outer diameter side of each thin magnetic steel plate A step of superposing rotor slots and laminating a predetermined number of thin magnetic steel plates to form a rotor core, and among the inner diameter side rotor slot and the outer diameter side rotor slot formed in the rotor core And a step of inserting a copper bar into at least the inner diameter side rotor slot and a step of filling a gap between the inner diameter side rotor slot and the copper bar with aluminum or an aluminum alloy by die casting. .

Since the rotating electrical machine of the present invention has arcuate curved portions convex in the inner diameter direction on the left and right shoulders on the outer diameter side of the outer diameter side rotor slot, the loss of the rotating electric machine is reduced and the efficiency is improved. Can do.

Further, the manufacturing method of the rotating electrical machine of the present invention includes a step of inserting a copper bar into at least the inner diameter side rotor slot of the inner diameter side rotor slot and the outer diameter side rotor slot formed in the rotor core; Since the step of filling aluminum or aluminum alloy with die casting in the gap between the inner diameter side rotor slot and the copper bar is included, a rotor conductor excellent in conductivity can be easily manufactured.

It is principal part sectional drawing of the rotary electric machine which concerns on embodiment. It is a perspective view of the double basket type rotor concerning an embodiment. 1 is an axial cross-sectional view of a double squirrel-cage rotor according to Embodiment 1. FIG. It is a principal part enlarged view of FIG. It is explanatory drawing of the slot part formed in the double cage rotor which concerns on Example 1. FIG. It is explanatory drawing of the slot part formed in the double cage rotor based on Example 2. FIG. It is explanatory drawing of the slot part formed in the double cage rotor which concerns on the modification 1. FIG. It is explanatory drawing of the slot part formed in the double cage rotor which concerns on the modification 2. FIG. It is explanatory drawing of the slot part formed in the double cage rotor which concerns on the modification 3. FIG. 6 is a side view and an enlarged view of a double squirrel-cage rotor according to Embodiment 3. FIG. FIG. 10 is a side view and an enlarged view showing another example of a double squirrel-cage rotor according to Embodiment 3. It is the side view and enlarged view which show the further another example of the double cage rotor which concerns on Example 3. FIG. 6 is an enlarged view of a first thin magnetic steel plate according to Example 3. FIG. It is an enlarged view of the 2nd thin plate magnetic steel plate concerning Example 3. FIG. It is a figure which shows the dimension of the internal diameter side bridge | bridging formed in the 2nd thin plate magnetic steel plate which concerns on Example 3. FIG. 6 is an enlarged view of a thin magnetic steel plate according to Example 4. FIG. 6 is an enlarged view of a thin magnetic steel plate according to Example 5. FIG.

Hereinafter, an embodiment of a rotating electrical machine according to the present invention will be described using a three-phase induction motor as an example and referring to the drawings for each example.

As shown in FIG. 1, the rotating electrical machine 100 according to the embodiment includes a cage rotor 1 and a stator 65 arranged concentrically. The cage rotor 1 includes a shaft (output shaft) 9, a rotor core 2 fixed to the shaft 9, an inner diameter side rotor conductor 3 and an outer diameter side rotor conductor 5 provided on the rotor core 2, and A short-circuit ring 70 is provided to connect both ends of the inner diameter side rotor conductor 3 and the outer diameter side rotor conductor 5. Therefore, the cage rotor 1 of this example has a double cage structure. On the other hand, the stator 65 includes a stator core 60, a stator slot 61 formed in the stator core 60, and a stator winding 62 wound around the stator slot 61.

As shown in FIG. 2, the rotor core 2 is formed of a thin magnetic steel plate, and the entire shape is formed into a cylindrical shape by laminating a predetermined number of sheets in the thickness direction. The predetermined number of rotor cores 2 are integrated by inserting a shaft 9 into the center hole thereof.

As shown in FIGS. 3 and 4, the rotor core 2 is formed with an inner diameter side rotor slot 4 and an outer diameter side rotor slot 6 at regular intervals on a circumference centered on the axis of the shaft 9. Has been. Both the inner diameter side rotor slot 4 and the outer diameter side rotor slot 6 are formed in a sealed shape. Between the outer peripheral end of the inner diameter side rotor slot 4 and the inner peripheral end of the outer diameter side rotor slot 6, an inner diameter side bridge 7 having a predetermined dimension is formed, and the outer diameter side rotor slot 6 and the rotor core 2 are separated from each other. Between the outer peripheral ends, an outer diameter side bridge 8 having a predetermined dimension is formed. The widths of the inner diameter side bridge 7 and the outer diameter side bridge 8 are set to values capable of press punching the inner diameter side rotor slot 4 and the outer diameter side rotor slot 6 with high efficiency and high accuracy.

In the inner diameter side rotor slot 4 and the outer diameter side rotor slot 6, the inner diameter side rotor conductor 3 and the outer diameter side rotor conductor 5 are formed by die-casting aluminum or an aluminum alloy. The die casting method for the inner diameter side rotor conductor 3 and the outer diameter side rotor conductor 5 is a well-known matter and is not the gist of the present invention. As described above, both ends of each inner diameter side rotor conductor 3 and each outer diameter side rotor conductor 5 are connected by the short-circuit ring 70 (see FIG. 1).

The planar shape of the inner diameter side rotor slot 4 (the sectional shape of the inner diameter side rotor conductor 3) is formed in a substantially sector shape with rounded corners as shown in FIGS. The outer diameter side end of the inner diameter side rotor slot 4 is formed in a linear shape.

On the other hand, the planar shape of the outer diameter side rotor slot 6 (the cross sectional shape of the outer diameter side rotor conductor 5) is the inner diameter side rotor slot 4 and the outer diameter side rotor slot 6 as shown in FIGS. Centering on the radial line XX of the rotor core 2 passing through the center of the core, arc-shaped curved portions 10 convex in the inner diameter direction are formed in left and right shoulders on the left and right sides thereof in a symmetrical manner. ing. The inner diameter side end of the outer diameter side rotor slot 6 is formed in a straight line shape facing the outer diameter end of the inner diameter side rotor slot 4, and the straight line portion and the curved portion 10 are connected by an arc. . As a result, the circumferential width of the outer diameter side rotor slot 6 is approximately raised to s1, s2, and s3 along the curved portion 10 as it reaches the outer diameter side of the cage rotor 1 as shown in FIG. Decrease.

The higher the frequency of the harmonic current flowing through the conductor, the more concentrated the current flows on the outer diameter side of the conductor due to the skin effect, so the higher the frequency of the harmonic current, the higher the frequency of the harmonic current. Concentrate on the side. FIG. 5 shows that the harmonic flux 33 having the highest frequency among the

harmonic fluxes

31, 32, 33 caused by the influence of the stator slot and the ripple current when driving the inverter is the outer diameter of the outer diameter side rotor conductor 5. The harmonic magnetic flux 31 having the lowest frequency passing through the portion close to the end on the side passes through the portion close to the end on the inner diameter side of the outer diameter side rotor conductor 5, and the harmonic magnetic flux 32 having an intermediate frequency between them. Indicates passing through the central portion of the outer diameter side rotor conductor 5. The main magnetic flux 30 having a frequency lower than that of the harmonic

magnetic fluxes

31, 32, 33 returns to the stator core 60 through the inner diameter side further than the inner diameter side rotor conductor 3.

In the outer diameter side rotor slot 6 according to the first embodiment, the arc-shaped curved portion 10 convex in the inner diameter direction is formed on the shoulder portion on the outer diameter side in a bilaterally symmetrical manner. The length across the outer diameter side rotor slot 6 is shortened. The reluctance of the portion across the outer diameter side rotor slot 6 is inversely proportional to the length of the magnetic flux across the outer diameter side rotor slot 6, so that the higher the frequency of the harmonic current flowing through the outer diameter side rotor conductor 5, the higher the magnetic resistance. The magnetic flux generated by the harmonic current is easy to pass. That is, the inductance increases with increasing frequency.

The current flowing through the

rotor conductors

3 and 5 is divided into a fundamental wave component that flows through the entire conductor at the slip frequency and becomes the output of the rotating electrical machine, and a harmonic component that flows through the conductor due to the harmonic magnetic flux and becomes a loss. Can think. Since the slip frequency is generally lower than the stator current, the influence of the inductance due to the rotor leakage magnetic flux is small on the fundamental wave component, and the influence of the resistance is large on the magnitude of the flowing current. On the other hand, since the harmonic current is generated by the harmonic magnetic flux resulting from the stator slot and the inverter drive, the harmonic frequency is often a relatively high frequency of several kHz or more, and the influence of the inductance is increased. Therefore, when the impedance is increased by increasing the inductance due to the harmonic current flowing in the outer diameter side rotor conductor 6 as in this embodiment, the harmonic current causing the loss can be selectively reduced. An efficient rotating electrical machine can be provided. Further, since the flux linkage at the time of starting does not decrease, a sufficient torque can be obtained at the time of starting.

The rotating electrical machine according to the second embodiment will be described with reference to FIG. The rotating electrical machine according to the second embodiment is characterized in that the dimensions of each part of the outer diameter side rotor slot 6 formed in the rotor core 2 of the rotating electric machine 100 according to the first embodiment are optimized.

As shown in FIG. 6, the end portion 11 on the inner diameter side of the curved portion 10 formed in the outer diameter side rotor slot 6 is closer to the inner diameter side than half of the radial length 2d of the outer diameter side rotor slot 6. Deploy. Further, the circumferential width e from the end portion 11 on the inner diameter side of the curved portion 10 to the end portion 13 on the outer diameter side is set to be larger than half the radial direction length of the outer diameter side rotor slot 6, The ratio at which the circumferential width of the rotor slot 6 is reduced in the outer diameter direction is increased. Thereby, a harmonic current can be reduced efficiently and the loss of a rotary electric machine can be reduced.

The radial height 2d of the outer diameter side rotor slot 6 shown in FIG. 6 is preferably determined according to the skin depth that can be calculated from the frequency of the main harmonic. In general, the harmonic component of the current flowing through the rotor conductor is mainly an integer multiple of the number of stator slots or an integer multiple of the inverter carrier frequency with respect to the frequency of the current passed through the stator winding. . Therefore, the electrical conductivity of the rotor conductor is σ (S / m), the relative permeability is μr (H / m), the rotational speed of the rotating electrical machine is N, the number of stator slots is Ns, and the rotating electrical machine is driven. When the carrier frequency of the inverter to be operated is fc (Hz), the radial height 2d of the outer diameter side slot 6 is
Skin depth of stator slot harmonic obtained by √ (1 / π · N · Ns · μr · σ), or skin depth of inverter carrier harmonic obtained by √ (1 / π · fc · μr · σ) Set a value smaller than the one that has a large effect.

When the radial height 2d of the outer diameter rotor slot 6 is set to the skin depth of the harmonic having the greatest influence, the magnetic flux generated by the harmonic current of the same frequency passes through the inner diameter bridge 7, and thus the inductance is large. Impedance can be increased for harmonics that have a great influence, and harmonic current can be effectively reduced. Further, as described above, when the end portion on the inner diameter side of the curved portion 10 is set closer to the inner diameter side than the half of the radial length 2d of the outer diameter side rotor slot 6 with respect to an integral multiple of harmonics, Since the circumferential width of the outer diameter side slot 6 can be made particularly small within the range of the skin depth of the harmonic current or less, it is more effective in reducing the harmonic current and hence the loss.

In the rotating electrical machines according to the first and second embodiments, the curved portion 10 of the outer diameter side rotor slot 6 formed in the rotor core 2 is bilaterally symmetric, and is externally disposed between the left and right curved portions 10. Although the land portion (s3 in FIG. 5) convex toward the radial side is provided, the gist of the present invention is not limited to this. The shape of the outer diameter side rotor slot 6 can be variously changed as shown in FIGS.

(1) In the example of FIG. 7, the land portion is not formed between the left and right curved portions 10.

(2) In the example of FIG. 8, the radial line X of the rotor core 2 passing through the center of the inner diameter side rotor slot 4 and the outer diameter side rotor slot 6 through the left curved portion 10a and the right curved portion 10b. The shape is asymmetric with respect to −X.

(3) In the example of FIG. 9, the land portion 10c is formed between the left and right curved portions 10, and the shape of the land portion 10c is a convex curve toward the inner diameter side.

Next, the rotating electrical machine according to the third embodiment will be described with reference to FIGS. 10 to 14. The rotating electrical machine according to the third embodiment does not constitute a rotor core 2 by laminating a predetermined number of thin magnetic steel plates having the same configuration, but by laminating two types of thin magnetic steel plates having different rotor slot shapes, The rotor core 2 is configured.

FIG. 10 shows an example in which two types of thin

magnetic steel plates

41 and 42 having different rotor slot shapes are alternately laminated one by one, and FIG. 11 shows two types of thin

magnetic steel plates

41 and 42 having different rotor slot shapes. This is an example in which three sheets are alternately stacked. Further, FIG. 12 shows an example in which two thin magnetic steel plates 41 are alternately laminated on each of the two types of thin

magnetic steel plates

41 and 42 having different rotor slot shapes.

As shown in FIG. 13, the thin magnetic steel plate 41 is similar to the thin magnetic steel plate used in the rotating electrical machine 65 according to the first and second embodiments, and the inner circumferential rotor slot 4 and the An outer rotor slot 6 is formed. On the other hand, as shown in FIG. 14, the thin magnetic steel plate 42 does not have the inner diameter side bridge 7, and corresponds to the portion corresponding to the inner peripheral side rotor slot 4 and the outer peripheral side rotor slot 6. An unbridged slot 12 is formed in a series of portions.

As described above, the inner bridge 7 formed on the rotor core 2 serves as a path for magnetic flux generated by the harmonic current flowing through the outer rotor conductor 5, so as shown in FIG. The radial width b of the circumferential bridge 7 plays an important role in increasing the self-inductance of the cage rotor 1 with respect to the harmonic magnetic flux flowing through the outer diameter rotor conductor 5. However, if the radial width b of the inner circumferential bridge 7 is too large, the main magnetic flux that should be linked to the entire rotor conductor passes through the inner circumferential bridge 7. The amount of magnetic flux decreases and the output of the rotating electrical machine decreases. On the other hand, when the rotor core 2 is manufactured by punching a thin magnetic steel plate with a punch, the radial width b of the inner peripheral bridge 7 is a limit value corresponding to the thickness of the steel plate in order to avoid deformation and breakage during punching. Is decided. Since the thickness of the thin magnetic steel plate that is generally used is generally about 0.3 to 0.5 mm, the limit value of the radial width b at the time of punching is often approximately equal to or greater than the thickness of the thin magnetic steel plate. For this reason, the limit dimension at the time of punching may become larger than the dimension which can avoid the reduction | decrease of a main magnetic flux.

Therefore, as shown in FIG. 10, when the thin magnetic steel plates 41 having the inner bridges 7 and the thin magnetic steel plates 42 having the bridgeless slots 12 are alternately laminated one by one, for example, the diameter of the inner bridge 7 Even if a steel plate made with a direction width b of 1.0 mm due to punching restrictions is used, the entire magnetic circuit of the rotor core 2 has an inner diameter side bridge 7 with a radial width of 0.5 mm for each thin magnetic steel plate. It becomes equivalent to what was formed, and leakage of the main magnetic flux can be reduced. In addition, as illustrated in FIG. 11, the same effect can be obtained when a plurality of thin magnetic steel plates 42 having the inner bridge 7 and thin magnetic steel plates 42 having the bridgeless slots 12 are alternately laminated. can get. Furthermore, as illustrated in FIG. 12, when the thin magnetic steel plates 41 having the inner diameter side bridges 7 are alternately laminated by two thin magnetic steel plates 42 each having the bridgeless slot 12 formed, for example, Even if a steel plate prepared by setting the radial width b of the inner peripheral bridge 7 to 1.0 mm due to punching restrictions is used, the radial width of each thin magnetic steel plate is 0.00 mm in the entire magnetic circuit of the rotor core 2. This is equivalent to a structure in which a 33 mm inner diameter side bridge 7 is formed, and leakage of main magnetic flux can be reduced. The number of the two types of thin magnetic steel plates with different rotor slot shapes can be appropriately set depending on the radial width b to be configured and the manufacturing convenience.

As described above, in the rotating electrical machine according to the third embodiment, the radial width of the inner peripheral bridge 7 formed on the rotor core 2 by appropriately stacking two kinds of thin magnetic steel plates having different rotor slot shapes. Since b is optimized, the leakage of the main magnetic flux in the inner peripheral bridge 7 can be reduced, and the output reduction of the rotating electrical machine can be minimized.

Next, the rotating electrical machine according to the fourth embodiment will be described with reference to FIG. The rotating electrical machine according to the fourth embodiment does not constitute the rotor core 2 by laminating two kinds of thin magnetic steel plates having different rotor slot shapes, but the rotor slot having the inner diameter side bridge 7 and the inner diameter. A rotor core 2 is configured by laminating thin magnetic steel plates formed in a predetermined arrangement in the circumferential direction with a rotor slot 12 having no side bridge 7.

In the example of FIG. 16, in the circumferential direction of the thin magnetic steel plate, there are an inner peripheral side rotor slot 4 and an outer peripheral side rotor slot 6 that are arranged radially via an inner diameter side bridge 7, and an inner diameter side bridge 7. However, the bridge-less slots 12 in which a portion corresponding to the inner rotor slot 4 and a portion corresponding to the outer rotor slot 6 are formed in series are alternately formed at a constant pitch. Yes.

When each rotor slot is formed in such an arrangement in a thin magnetic steel plate, an inner circumferential rotor slot 4 and an outer circumferential rotor slot arranged radially on the bridgeless slot 12 via the inner bridge 7. The rotor core 2 similar to that shown in FIG. 10 can be configured by adjusting the circumferential positions of the thin magnetic steel plates arranged in contact with each other so as to overlap each other. In addition, the arrangement | sequence of the inner peripheral side rotor slot 4 and the outer peripheral side rotor slot 6 which are arrange | positioned radially via the inner diameter side bridge | bridging 7, and the slot 12 without a bridge | bridging is alternately and fixed pitch one by one. However, the present invention is not limited thereto, and a plurality of these rotor slots can be alternately formed at a constant pitch. Similarly to the rotating electrical machine according to the third embodiment, the rotor core 2 can be configured by stacking two types of thin magnetic steel plates having different rotor slot arrangements.

The rotating electrical machine according to the fourth embodiment has the same effect as the rotating electrical machine according to the third embodiment.

Next, the rotating electrical machine according to the fifth embodiment will be described with reference to FIG. The rotating electrical machine according to the fifth embodiment is characterized in that a copper bar 51 is inserted into the inner diameter side rotor slot 4.

That is, in the rotating electrical machine according to the fifth embodiment, as shown in FIG. 17, the inner circumferential rotor slot 4 and the outer circumferential rotor slot 6 arranged in the radial direction via the inner diameter bridge 7 are arranged in the circumferential direction. The rotor core 2 is formed at a constant pitch. A copper bar 51 is inserted into the inner circumferential rotor slot 4, and the gap between the inner surface of the inner circumferential rotor slot 4 and the outer surface of the copper bar 51 is filled with aluminum or an aluminum alloy by die casting. ing. The outer rotor slot 6 is filled with aluminum or aluminum alloy by die casting. The other parts are the same as those of the rotating electrical machine according to the first embodiment, and thus the corresponding parts are denoted by the same reference numerals and the description thereof is omitted.

Copper has a higher electrical conductivity than aluminum and is therefore suitable as a rotor conductor. However, since copper has a higher melting point than aluminum, it is difficult to costly fill the rotor slot by die casting. . Therefore, when a copper bar is used as the rotor conductor, a method of inserting a solid copper bar into a rotor slot formed in the rotor core is generally used. However, the rotor core 2 according to the embodiment is not limited. Thus, it is difficult to insert a solid copper bar into a rotor slot having a relatively complicated shape without a gap. Therefore, as shown in FIG. 16, after inserting the solid copper bar 51 into the inner rotor slot 4, aluminum or aluminum is formed in the gap between the inner surface of the inner rotor slot 4 and the outer surface of the copper bar 51. When the aluminum alloy is filled by die casting, the inner surface of the inner peripheral rotor slot 4 having a complicated shape and the outer surface of the copper bar 51 can be electrically and reliably connected. Although illustration is omitted, the copper bar 51 can also be inserted into the outer rotor slot 6.

In the rotating electrical machine according to the fifth embodiment, since the copper bar 51 is inserted into the rotor slot 4 formed in the rotor core 2, the electrical conductivity of the rotor conductor can be increased, and the efficiency of the rotating electrical machine is further improved. can do. Further, after inserting the solid copper bar 51 into the inner rotor slot 4, aluminum or an aluminum alloy is filled in the gap between the inner surface of the inner rotor slot 4 and the outer surface of the copper bar 51 by die casting. Therefore, the inner peripheral rotor conductor 3 having good conductivity can be easily manufactured.

DESCRIPTION OF SYMBOLS 1 Rotor 2 Rotor core 3 Inner diameter side rotor conductor 4 Inner diameter side rotor slot 5 Outer diameter side rotor conductor 6 Outer diameter side rotor slot 7 Inner diameter side bridge 8 Outer diameter side bridge 9

Shaft

10, 10a to 10c Curve Part 11 Curved part inner diameter side edge 12 Bridgeless slot 13 Curved part outer diameter side edge part 30 Main magnetic flux 31 to 33 Harmonic

magnetic flux

41, 42 Thin magnetic steel sheet 51 Copper bar 60 Stator core 61 Stator slot 62 Fixed Child winding 65 Stator 70 Short circuit ring

Claims

A stator and a rotor rotatably disposed in the stator;
The rotor includes a rotor core made of a laminate of a large number of thin magnetic steel sheets, an inner diameter side rotor slot and an outer diameter side rotor slot having a sealed structure formed on the rotor core, and the inner diameter side rotor. A double cage structure having an inner diameter side rotor conductor formed in the slot and an outer diameter side rotor conductor formed in the outer diameter side rotor slot;
The rotating machine according to claim 1, wherein the outer-diameter-side rotor slot has arcuate curved portions convex in the inner-diameter direction at left and right shoulders on the outer-diameter side.
2. The rotating electrical machine according to claim 1, wherein the curved portion is formed such that a circumferential width of the outer-diameter side rotor slot gradually decreases as the outer-diameter direction of the rotor core is reached.
2. The rotating electrical machine according to claim 1, wherein an end portion on an inner diameter side of the curved portion is arranged on an inner diameter side with respect to a half of a radial length of the outer diameter rotor slot.
The circumferential width from the inner diameter side end portion to the outer diameter side end portion of the curved portion is set to be larger than half of the radial length of the outer diameter side rotor slot. Rotating electric machine.
The electrical conductivity of the inner diameter side rotor conductor and the outer diameter side rotor conductor is σ (S / m), the relative permeability is μr (H / m), the number of rotations per second of the rotating electrical machine is N, and the stator When the number of slots is Ns, the radial height of the outer-diameter-side rotor slot is greater than the skin depth of the stator slot harmonic represented by √ (1 / π · N · Ns · μr · σ). The rotating electrical machine according to claim 1, wherein the rotating electrical machine is reduced in size.
When the carrier frequency of the inverter driving the rotating electrical machine is fc, the conductivity of the inner diameter side rotor conductor and the outer diameter side rotor conductor is σ (S / m), and the relative permeability is μr (H / m). The radial height of the outer-diameter side rotor slot is made smaller than the skin depth of the inverter carrier harmonic expressed by √ (1 / π · fc · μr · σ). The rotating electrical machine described in 1.
The rotor iron core does not have the first thin-plate magnetic steel plate in which the inner peripheral rotor slot and the outer peripheral rotor slot are formed via the inner diameter bridge, and the inner diameter bridge, A portion corresponding to the inner rotor slot and a portion corresponding to the outer rotor slot are formed of a laminated body with a second thin sheet magnetic steel plate in which a bridge-less slot is formed; The inner bridge, the inner rotor slot, and the outer rotor slot formed in one thin magnetic steel plate are overlapped with the non-bridge slot formed in the second thin magnetic steel plate. The rotating electrical machine according to any one of claims 1 to 6, wherein the rotating electrical machine is characterized in that:
The rotor iron core is configured with a laminate of a plurality of thin magnetic steel plates, and the inner side formed in the radial direction of the thin magnetic steel plates via the inner diameter side bridge in the circumferential direction of the thin magnetic steel plates. A peripheral rotor slot, the outer peripheral rotor slot, and the inner diameter bridge are not provided, and a portion corresponding to the inner peripheral rotor slot and a portion corresponding to the outer peripheral rotor slot are a series. The inner bridge, the inner rotor slot, and the outer rotor formed on one of the two thin magnetic steel plates that are formed at a constant pitch and are arranged in contact with each other. The rotating electrical machine according to any one of claims 1 to 6, wherein the slot is overlapped with the slot without bridge formed in the other thin magnetic steel plate.
Of the inner diameter side rotor conductor formed in the inner diameter side rotor slot and the outer diameter side rotor conductor formed in the outer diameter side rotor slot, formed in at least the inner diameter side rotor slot. The inner diameter side rotor conductor is made of a copper bar inserted into the inner diameter side rotor slot and aluminum or an aluminum alloy filled between the inner diameter side rotor slot and the copper bar. The rotating electrical machine according to claim 1.
A process of forming a predetermined number of thin magnetic steel plates having an inner diameter side rotor slot and an outer diameter side rotor slot, and a predetermined number of sheets by superimposing the inner diameter side rotor slots and the outer diameter side rotor slots of each thin plate magnetic steel sheet. Laminating thin magnetic steel plates to form a rotor core, and among the inner diameter side rotor slot and the outer diameter side rotor slot formed in the rotor core, at least in the inner diameter side rotor slot A method of manufacturing a rotating electrical machine, comprising: a step of inserting a copper bar; and a step of filling aluminum or an aluminum alloy into a gap between the inner diameter side rotor slot and the copper bar by die casting.