WO2019202790A1

WO2019202790A1 - Dynamo-electric machine, and elevator hoist system

Info

Publication number: WO2019202790A1
Application number: PCT/JP2019/001064
Authority: WO
Inventors: 大祐郡; 豪希原; 雅章遠藤; 元信飯塚
Original assignee: 株式会社日立製作所
Priority date: 2018-04-16
Filing date: 2019-01-16
Publication date: 2019-10-24
Also published as: JP2019187164A

Abstract

The purpose of the present invention is to provide a dynamo-electric machine system in which, in order to reduce a torque ripple, the position and size of an air gap provided in a rotor core are appropriately set to improve the a torque ripple reduction effect. In order to achieve the purpose, this dynamo-electric machine has a rotor provided inside thereof, and a stator provided outside thereof. The rotor has a shaft which serves as a rotating shaft, a substantially circular tube-shaped rotor core which is affixed to the outer periphery of the shaft, and a plurality of permanent magnets which are arranged side by side in a circumferential direction on the outer peripheral surface of the rotor core. The rotor core has a pair of protrusions which protrude outward at positions sandwiching both end surfaces of a permanent magnet, and has, provided at positions facing both ends of the permanent magnet, a pair of recesses cut into the inside or a pair of voids provided inside the rotor core. The width T of the protrusions and the width W of the recess or the void satisfy the expression of width T < width W.

Description

Rotating electric machine and elevator hoisting system

The present invention relates to a rotating electric machine suitable for use as an elevator hoisting machine, and an elevator hoisting machine system using the rotating electric machine.

In the past, induction motors were often used as rotating machines for hoisting elevators, but in recent years, they are more suitable for smaller and lighter weight and higher efficiency due to the lower price of permanent magnets and the spread of high-performance inverters. Motivation to use permanent magnet rotating electrical machines is increasing.

Here, as with cars and trains, elevators on which people ride are required to have a comfortable ride, but torque ripple generated by a permanent magnet type rotating electrical machine contributes to a deterioration in ride comfort. . Further, when a rotating electrical machine and a gear are connected as in a high-speed, large-mass type elevator hoisting system, torque ripple is a cause of a reduction in the reliability of the gear. Therefore, in order to improve the riding comfort of the elevator and the reliability of the gear, it is necessary to reduce the torque ripple of the permanent magnet type rotating electrical machine. In order to reduce the torque ripple of the permanent magnet type rotating electrical machine, various rotating electrical machine structures have been proposed.

For example, in Patent Document 1, the permanent magnet of the rotor is arranged in an arc shape on the surface of the rotor core, the inner peripheral surface of the permanent magnet and the outer peripheral surface of the rotor core are in close contact with each other near the magnetic pole center, and a gap is provided near the magnetic pole boundary. It has a rotor structure.

In Patent Document 2, a groove is provided in the rotor core in the radial direction on the surface on which the permanent magnet of the rotor core is attached, and the groove is changed along the axial direction.

JP 2001-8392 A JP 2011-15458 A

In Patent Document 1, arc-shaped magnets are arranged on the outer peripheral surface of the rotor core, and a gap is provided in the rotor core on the inner diameter side at both ends of the arc-shaped magnet. Thereby, the magnetic flux density in the magnet central part is increased, the magnetic flux density in the magnetic pole part is decreased, and a smooth rotational force is obtained. However, if this gap is excessively increased, the magnetic resistance on the back surface of the magnet is increased, making it difficult for the magnetic flux to flow, resulting in a decrease in torque. However, Patent Document 1 fully considers this problem. It has not been.

Further, in Patent Document 2, a torque ripple is reduced by providing a groove at one end of the magnet and changing the groove in the axial direction toward the opposite end of the magnet. However, in the case of forming this groove, as is apparent from FIG. 4 and the like of the same document, the groove located near the center in the axial direction passes through the magnet central portion. As described above, this leads to lowering of the magnetic flux density at the magnet central portion, so that the effect of reducing torque ripple cannot be expected so much.

To reduce torque ripple, it is effective to make the gap magnetic flux density between the rotor and stator close to a sine wave. To achieve this, it is important to provide gaps such as gaps and grooves as in the above-mentioned patent documents, but there is room for further improvement in the position and size of the gaps and the like disclosed by both patent documents. Is left.

The present invention is based on the problems of both patent documents, and by optimizing the position and size of the air gap provided in the rotor core, the permanent magnet achieves both maintenance of torque and suppression of torque ripple. An object of the present invention is to provide a rotary electric machine and an elevator hoisting system using the same.

In order to achieve the above object, a rotating electrical machine of the present invention is provided with a rotor on the inside and a stator on the outside, and the rotor is provided on a shaft serving as a rotating shaft and on an outer periphery of the shaft. A fixed substantially circular tubular rotor core, and a plurality of permanent magnets arranged in a circumferential direction on the outer peripheral surface of the rotor core, the rotor core having both end faces of the permanent magnet A pair of convex portions projecting outward at a position sandwiching the inner surface, and a pair of concave portions notched inward at a position facing both ends of the permanent magnet or provided inside the rotor core The width T of the convex part and the width W of the concave part or the hole satisfy the width W <width T.

According to the permanent magnet type rotating electrical machine of the present invention, torque ripple can be reduced while maintaining the necessary torque.

FIG. 4 is a quarter cross-sectional view of the rotating electrical machine according to the first embodiment. FIG. 3 is an enlarged view of an outer peripheral portion of the rotor according to the first embodiment. The graph which shows the relationship between the shape of the space | gap of Example 1, torque, and a torque ripple. FIG. 3 is a schematic view showing the shape of a permanent magnet of Example 1. FIG. 14 is a quarter cross-sectional view of a rotating electrical machine according to a modification of the first embodiment. FIG. 14 is a quarter cross-sectional view of a rotating electrical machine according to a modification of the first embodiment. FIG. 4 is an enlarged view of an outer peripheral portion of a rotor according to a second embodiment. FIG. 6 is an enlarged view of an outer peripheral portion of a rotor according to a third embodiment. The graph which shows the relationship between the shape of the surrounding fastening part of Example 3, and a torque ripple. FIG. 6 is an enlarged view of an outer peripheral portion of a rotor according to a fourth embodiment. The enlarged view of the boundary of the rotor of Example 5, and a stator. 10 is a graph showing a relationship between a magnetic field and a magnetic flux density in the stator core and the wedge of Example 5. Sectional drawing of the rotary electric machine of Example 6. FIG. The graph which shows the relationship between the shape of the rotary electric machine of Example 6, and a torque ripple. Sectional drawing of the elevator winding system of Example 7. FIG. Sectional drawing of the elevator winding system of Example 7. FIG.

Hereinafter, the details of the present invention will be described with reference to the drawings. In each figure, the same part is given the same number.

FIG. 1 is a quarter cross-sectional view of a rotor 1 and a stator 2 in a rotating electrical machine 100 according to a first embodiment of the present invention. The rotating electrical machine 100 illustrated here has a 56-pole rotor 1 on the inside, a 72-slot stator 2 on the outside, and a concentrated winding permanent magnet having a predetermined gap 7 therebetween. This is a rotary electric machine. In addition, this rotary electric machine 100 assumes the thing for high-speed and heavy loads which are mainly used for an elevator hoisting machine and have an output of several hundred kW and a rotational speed of several hundred [min ⁻¹ ] class. However, the number of poles of the rotor 1, the number of slots of the stator 2, the winding method, the output, the rotation speed, and the application are not limited to the above examples.

As shown here, the substantially cylindrical rotor 1 includes a shaft 8 serving as a rotating shaft, a substantially tubular rotor core 3 fixed to the outer peripheral side, and a circumferential surface with alternating polarity on the outer peripheral surface. It consists of a plurality of permanent magnets 5 arranged side by side in the direction. The substantially tubular stator 2 includes a substantially tubular stator core 4 and a plurality of coils 6 disposed on the inner peripheral side of the stator core 4. More specifically, the stator core 4 is a space formed between the teeth 4b and a cylindrical core back 4a, a plurality of teeth 4b arranged in the circumferential direction on the inner peripheral side of the core back 4a, and the teeth 4b. A plurality of slots 4c are configured, and a coil 6 is formed in each slot 4c by winding an electric wire around the teeth 4b. Note that the rotor core 3 and the stator core 4 may be formed by stacking and molding press-worked electromagnetic steel sheets, or may be integrally formed by casting.

The left view of FIG. 2 is an enlarged view of two poles on the outer peripheral surface of the rotor 1. As shown here, the rotor 1 is a surface magnet type rotor in which a flat permanent magnet 5 is fixed to the outer peripheral surface of the rotor core 3.
Further, on the outer peripheral surface of the rotor core 3, a pair of gaps 9 (also referred to as “concave portions”) notched inward are provided at positions facing both ends of each permanent magnet 5, A pair of peripheral fastening portions 10 (also referred to as “convex portions”) projecting outward are provided at positions where both end surfaces of the permanent magnet 5 are sandwiched. The peripheral fastening portion 10 is in surface contact with the circumferential end surface of the permanent magnet 5 so that the permanent magnet 5 is not displaced in the circumferential direction. In the case where the flat permanent magnet 5 is used as in the present embodiment, the circumferential end surface of the rotation retaining portion 10 is connected to the d axis 11 connecting the rotation center of the rotor 1 and the magnetic pole center of the permanent magnet 5. If it is made substantially parallel (that is, if the surrounding clasp part 10 is made into a radial shape), the circumferential end faces of both the permanent magnet 5 and the circumscribing part 10 can be brought into surface contact, and the permanent magnet 5 is firmly fixed. can do. 2 shows an example in which a pair of recesses is provided for each permanent magnet 5, it is sufficient that at least one permanent magnet is provided with a pair of recesses, and these are provided for each permanent magnet. It does not have to be. In addition, the direction in which a pair of recessed part and convex part are provided for every permanent magnet can raise the torque ripple reduction effect more.

2 is a further enlarged view of the vicinity of the peripheral fastening portion 10. FIG. In the case where the gap 9 and the surrounding clasp portion 10 are arranged as shown in the left diagram of FIG. 2, the surrounding clasp portion 10 is sandwiched between the pair of gaps 9. Taking the right side gap 9 as an example, the relationship between the gap 9 and the peripheral fastening part 10 will be described. The left circumferential end surface of the gap 9 is formed to form a plane with the right circumferential end face of the peripheral fastening part 10. Further, the circumferential end surface on the right side of the gap 9 is formed in parallel with the circumferential end face on the right side of the retaining portion 10 (that is, the circumferential end face on the left side of the gap 9). As described above, since the circumferential end surface of the peripheral clasp portion 10 is formed in parallel with the d-axis 11, any circumferential end surface of the gap 9 is formed in parallel with the d-axis 11.

Here, with reference to FIG. 3, the ratio of the circumferential width W of the gap 9 to the circumferential width T of the peripheral fastening portion 10 (hereinafter referred to as “W / T ratio”), the torque of the rotating electrical machine 100, The relationship of torque ripple will be described. The width W of the gap 9 is the length in the circumferential direction in which the gap 9 is widened in the direction of the d-axis 11 when the circumferential end surface of the retaining portion 10 is used as a reference position, as shown in the right diagram of FIG. It is.

In FIG. 3, the horizontal axis is the W / T ratio, and the vertical axis is the torque (right vertical axis) of the rotating electrical machine 100 with the value when the W / T ratio is 0 (when there is no gap 9) as 1. It is a normalized value of torque ripple (left vertical axis). As is apparent from the figure, when the W / T ratio is gradually increased from 0, the torque ripple indicated by the solid line rapidly decreases and maintains the minimum value after the vicinity of 0.25 is exceeded. For this reason, in order to suppress the torque ripple, it is necessary to increase the width W of the air gap 9 so that the W / T ratio exceeds 0.25 (that is, so as to satisfy the following expression 1).

0.25 × width T <width W (Formula 1)

On the other hand, when the W / T ratio is gradually increased from 0, the torque indicated by the two-dot chain line can be maintained substantially at a desired level while slightly decreasing in the range of 0 to 1, but the W / T If the ratio is greater than 1, the torque value in a state where there is no air gap 9 (W / T ratio = 0) is greatly deviated. For this reason, in order to maintain the torque, it is desirable to reduce the width W of the air gap 9 so that the W / T ratio is less than 1 (that is, so as to satisfy Equation 2 below).

Width W <width T (Formula 2)

Note that when the W / T ratio is 1 or more, the torque indicated by the two-dot chain line in FIG. 3 sharply decreases because the balance of the magnetic resistance around the interpolar portion deteriorates. As long as the above formula 2 is satisfied, the circumferential end magnetic flux of the permanent magnet 5 does not pass through the gap 7 and flows directly to the surrounding clasp 10 as a leakage flux, but the area of the clasp 10 is also small. As a result, the magnetic flux is always saturated due to the magnetic flux leakage of the magnet (the magnetic resistance is close to that of air). Therefore, even when the gap 9 is provided, it is possible to maintain substantially the same torque as when there is no gap 9. . On the other hand, when the width W of the air gap 9 is extremely widened and the above formula 2 is not satisfied, the magnetic resistance of the air gap 9 becomes larger than the magnetic resistance of the retaining portion 10, so that the magnetic flux flow is inhibited by the air gap 9 As a result, the torque of the rotating electrical machine 100 is significantly reduced.

As described above, the magnitude relationship between the width W of the gap 9 and the width T of the peripheral fastening portion 10 is closely related to the balance of the magnetic resistance around the interpolar portion and the magnitude of the torque. It is very important to set the position and size of the fastening portion 10 appropriately in order to achieve both reduction of torque ripple and maintenance of torque. That is, in order to achieve both the suppression of torque ripple and the maintenance of torque, it is desirable to set the width W of the air gap 9 within a range satisfying the following expression 3 including the

expressions

1 and 2.

0.25 × width T <width W <width T (Formula 3)

The characteristic shown in FIG. 3 is an example of the rotating electrical machine 100 using a flat plate as the permanent magnet 5, but the surface magnet type rotor for reducing the torque ripple is similar to the above-mentioned patent document. A D-shaped permanent magnet 12 or a tile-shaped permanent magnet 13 may be used.

FIG. 4 shows magnetic flux distributions of (a) the flat permanent magnet 5, (b) the D-shaped permanent magnet 12, and (c) the roof-shaped permanent magnet 13. The difference in magnetic flux distribution shown here appears as a difference in magnetic flux density distribution in the gap 7 when each magnet is used as the rotor 1 as it is. For example, when the D-shaped permanent magnet 12 or the tile-shaped permanent magnet 13 is used, the D-shaped or roof-shaped magnet shape appears in the magnetic flux density distribution as it is, and the magnetic flux density at the center of the magnet becomes the highest. Generally, torque ripple can be reduced by making the magnetic flux density distribution of the gap 7 close to a sine wave. Therefore, if the D-shaped permanent magnet 12 or the roof-shaped permanent magnet 13 can be used, the torque ripple can be easily reduced by the magnet shape itself. In other words, it can be said that torque ripple can also be suppressed by appropriately setting the magnet shape and dimensions.

On the other hand, when using the flat permanent magnet 5, the magnetic flux density distribution from the center to the end of the magnet is uniform as shown in FIG. Unlike the case where it is used, the magnetic flux density at the center of the magnet cannot be increased only by using the magnet shape, and the magnetic flux density distribution of the gap 7 cannot be approximated to a sine wave.

However, in this embodiment, as shown in FIG. 2, by providing a pair of gaps 9 having appropriate sizes at positions facing both ends of the permanent magnet 5, the magnetic flux density of the gap 7 is made close to a sine wave shape. As shown in FIG. 3, torque ripple can be reduced. That is, according to the configuration of the present embodiment, even when the plate-like permanent magnet 5 is used, the torque ripple reduction effect can be obtained in the same manner as when the D-shaped permanent magnet 12 or the tile-shaped permanent magnet 13 is used. Obtainable.

Here, in addition to the D-type permanent magnet 12 and the tile-shaped permanent magnet 13 being more expensive than the flat plate magnet, the rotor core 3 on which the D-type permanent magnet 12 and the roof tile permanent magnet 13 are mounted needs to have a more complicated surface shape than that on which the flat plate magnet is mounted. There is. As a result, when the D-shaped permanent magnet 12 and the tile-shaped permanent magnet 13 are used, man-hours and costs required for assembling the rotating electrical machine 100 are increased as compared with the case where a flat magnet is used.

On the other hand, when the cheap flat plate-like permanent magnet 5 is used, if the gap 9 satisfying the above-mentioned formula 3 and the surrounding fastening portion 10 are provided, the D-type permanent magnet 12 and the roof-shaped permanent magnet are suppressed while suppressing the manufacturing cost. As with the magnet 13, the rotating electrical machine 100 with reduced torque ripple can be provided at low cost.

Further, a flat permanent magnet 5 can be easily applied to a multi-pole surface magnet type rotor, such as the 56-pole rotor 1 illustrated in FIG. For example, if a flat magnet is applied to a rotor with a small number of poles, such as 4 poles and 6 poles, the cross-sectional shape of the rotor will be square or hexagonal, so the magnetic flux density distribution will become more steep and torque ripple will increase when rotating. Therefore, the torque ripple is generally suppressed by applying the D-shaped permanent magnet 12 or the tile-shaped permanent magnet 13. On the other hand, if the number of poles of the rotor is sufficiently large, the rotor outer diameter will be substantially circular even if a flat magnet is applied, so the combination of a multipole rotor and a flat magnet is effective in reducing torque ripple. Can be said to be compatible.

Furthermore, the corners of the permanent magnet 5 can be escaped by setting the start position for forming the air gap 9 to be the circumferential end face of the peripheral fastening portion 10 as in this embodiment. Usually, when the rotor core 3 is formed by press working or casting of an electromagnetic steel plate, it is necessary to provide curved portions at the corners. If the air gap 9 is provided as in the present embodiment, the permanent magnet 5 can be fixed in the circumferential direction without providing a useless clearance for reducing interference between the permanent magnet 5 and the rotor core 3 while reducing torque ripple. it can. Therefore, the rotor core 3 may be formed not only by the electromagnetic steel sheet but also by casting. By making the rotor core 3 into a casting, the number of assembling steps can be reduced as compared with the electromagnetic steel sheet, so that further cost reduction effect can be expected.

Next, a modification of the present embodiment will be described with reference to FIGS. 5A and 5B. In these modified examples, a cooling axial duct 14 is added to the rotor 1 of the rotating electrical machine 100 illustrated in FIG. In FIG. 5A, an axial duct 14 for flowing cooling air is formed between the rotor core 3 and the shaft 8 by connecting the rotor core 3 with a narrow width and the shaft 8 with bars 15 arranged radially. did. With this configuration, it is possible to reduce the weight while securing the rotor strength of the rotor core 3. In FIG. 5B, a plurality of axial ducts 14 are provided directly on the rotor core 3. With this configuration, it is possible to effectively flow cooling air to a portion to be cooled. In addition, if the radial position where the axial duct 14 is provided is too close to the permanent magnet 5 or the gap 9, the torque ripple reduction effect described above cannot be obtained, so the position where the axial duct 14 is provided is the outermost position of the permanent magnet 5. It is preferable to keep it within 70% of the diameter as a reference.

Next, the rotating electric machine 100 according to the second embodiment of the present invention will be described with reference to FIG. In addition, duplication description is abbreviate | omitted in common with Example 1. FIG.

FIG. 6 is a cross-sectional view of two poles of the rotor 1 in the rotating electrical machine of the second embodiment. In the present embodiment, as shown in FIG. 6, the air holes 16 are provided on the inner diameter side of the permanent magnet 5. The difference from the first embodiment is that the rotor core 3 is interposed between the hole 16 and the permanent magnet 5.

Thus, even if the hole 16 is provided at a position separated from the permanent magnet 5 inward in the radial direction, the same effect as in the first embodiment can be obtained. When the rotor core 3 is composed of an electromagnetic steel plate, the peripheral fastening portion 10 is formed by press working. At this time, when the circumferential width of the circumferentially fastened portion 10 is extremely short, there is a possibility that twisting or distortion may occur due to the influence of the press working, and when the gap 9 of Example 1 is extended toward the inner diameter direction, Since the base of the fastening portion 10 is thin, the strength of the surrounding fastening portion 10 may also be reduced.

On the other hand, as in the present embodiment, the rotor core 3 is interposed between the hole 16 and the permanent magnet 5, so that the same effect as that of the first embodiment can be realized, and the surrounding fastening portion 10 It is also possible to obtain the effect of ensuring the machining accuracy and strength. In the present embodiment, an example in which a pair of holes 16 is provided for each permanent magnet 5 is shown, but it is sufficient that a pair of holes 16 is provided in at least one permanent magnet. These may not be provided. In addition, the direction in which a pair of holes 16 are provided for each permanent magnet can further enhance the torque ripple reduction effect.

Next, the rotating electrical machine 100 according to the third embodiment of the present invention will be described with reference to FIGS. In addition, duplication description is abbreviate | omitted in common with the above-mentioned Example.

FIG. 7 is an enlarged view between the magnetic poles of the rotor 1 in the rotating electrical machine 100 according to the third embodiment, and shows a portion corresponding to the thickness Mh of the permanent magnet 5 and the protrusion amount Rh of the retaining ring 10.

Further, FIG. 8 shows the ratio between the protrusion amount Rh and the thickness Mh shown in FIG. 7 (hereinafter referred to as “Rh / Mh”) and the normalized value with the torque ripple being 1 when Rh / Mh is 1. Showing the relationship.
From this figure, it can be seen that when Rh / Mh is decreased, the torque ripple tends to decrease, and in particular, in the region where Rh / Mh is 0.5 or less, the torque ripple becomes the minimum value.

Here, when the thickness Mh of the permanent magnet 5 is constant, reducing Rh / Mh is equivalent to reducing the protrusion amount Rh of the surrounding clasp portion 10, so FIG. It can be understood that the torque ripple can be suppressed by reducing the protrusion amount Rh of 10. Such an effect is obtained because the amount of iron between the permanent magnets is reduced by reducing the amount of protrusion of the retaining portion 10, thereby reducing the leakage flux of the permanent magnet 5 and reducing the torque ripple. is there.

As described above, the torque ripple can be further reduced by the configuration of the present embodiment in which the protrusion amount Rh of the peripheral fastening portion 10 is smaller than the thickness Mh of the permanent magnet 5 as compared with the configuration of the first embodiment. be able to.

Next, the rotating electric machine 100 according to the fourth embodiment of the present invention will be described with reference to FIG. In addition, duplication description is abbreviate | omitted in common with the above-mentioned Example.

FIG. 9 is a cross-sectional view of two poles of the rotor 1 in the rotating electrical machine 100 of the fourth embodiment. As shown here, in this embodiment, the outer diameter of the rotor 1 is covered with a nonmagnetic material 17. The nonmagnetic material 17 may be a nonmagnetic metal such as stainless steel, aluminum, or copper, or may be a nonmetallic material such as plastic or carbon fiber.

In this way, by covering the outer diameter of the rotor 1 with the nonmagnetic material 17, in addition to the effects described in the first embodiment, even if the permanent magnet 5 is damaged, a fragment is formed on the inner side covered with the nonmagnetic material 17. Since it stays, scattering can be prevented. If scattering can be prevented, debris can be prevented from being caught in the gap 7 and damaging the stator 2. Further, if the space 18 formed between the nonmagnetic material 17 and the rotor 1 is filled with resin or the like, the permanent magnet 5 can be further fixed and scattering at the time of breakage can be suppressed.

Next, the rotating electrical machine 100 according to the fifth embodiment of the present invention will be described with reference to FIGS. Note that common explanation with the above-described embodiments is omitted.

FIG. 10 is a cross-sectional view of two slots of the stator 2 in the rotating electrical machine 100 of the fifth embodiment. As shown here, a slot 4 c is formed in the circumferential direction of the stator 2, a coil 6 is disposed in the slot 4 c, and a wedge 19 as a teeth connecting member is attached to the inner diameter side of the coil 6. . By providing this wedge 19, in addition to preventing the coil 6 from dropping into the gap 7, it is possible to reduce torque ripple.

FIG. 11 shows the magnetic characteristics of the stator core 4 and the wedge 19. As shown here, the wedge 19 of the present embodiment is a magnetic material, but is a material having a magnetic property worse than that of the stator core 4. The reason why the torque ripple can be reduced by using the wedge 19 having such a poor magnetic characteristic is that when the wedge 19 having the same magnetic characteristic as that of the stator core 4 is used, the leakage magnetic flux between the slots 4c increases and conversely the torque ripple. This is because, by using the wedge 19 having poor magnetic properties, the magnetic flux can be appropriately leaked between the slots 4c, and the torque ripple can be reduced.

Next, the rotating electric machine 100 according to the sixth embodiment of the present invention will be described with reference to FIGS. In addition, duplication description is abbreviate | omitted in common with the above-mentioned Example.

FIG. 12 is a sectional view in the axial direction of the rotor 1 and the stator 2 in the rotating electrical machine 100 of the sixth embodiment. As shown here, in this embodiment, the axial length Lst of the stator core 4 is made longer than the axial length Lmag of the permanent magnet 5 of the rotor 1.

FIG. 13 shows the relationship between the ratio Lst / Lmag between the length Lst and the length Lmag and the normalized value of the torque ripple. In addition, the vertical axis | shaft of the figure normalized the torque ripple when Lst / Lmag is 1 to 1. From this figure, it can be seen that torque ripple can be reduced by increasing Lst / Lmag. This is because the length Lst of the stator core 4 in the axial direction is longer than the length Lmag of the permanent magnet 5, thereby reducing the leakage magnetic flux at the axial end of the stator core 4 and thus reducing the torque ripple. Because.

Next, an elevator hoisting system according to a seventh embodiment of the present invention will be described with reference to FIGS. 14A and 14B. In addition, duplication description is abbreviate | omitted in common with the above-mentioned Example.

FIG. 14A is an example of an elevator hoisting machine system according to the present embodiment. The rotating electrical machine 100 according to any of Embodiments 1 to 6 and the sheave 20 around which the main rope of the elevator is wound are connected via a coupling 21. It is directly connected to drive. In FIG. 14A, the rotating electrical machine 100 is configured to support both ends of the shaft 8 with bearings 22.

On the other hand, FIG. 14B is also an example of the elevator hoisting machine system of the present embodiment, and the rotary electric machine 100 of any of the first to sixth embodiments and the sheave 20 are directly connected via the coupling 21 and driven. Is. In FIG. 14A, bearings 22 are installed at both ends of the shaft 8, but in FIG. 14B, the bearings 22 on the coupling 21 side are omitted. That is, the shaft 8 of the rotating electrical machine 100 is supported by the sheave 20. By doing in this way, the axial length of the elevator hoist system can be reduced. Moreover, since the bearing 22 can be eliminated, an effect of reducing the number of parts of the rotating electrical machine 100 can be obtained.

1 Rotor, 2 Stator, 3 Rotor Core, 4 Stator Core, 4a Core Back, 4b Teeth, 4c Slot, 5 Permanent Magnet, 6 Coil, 7 Gap, 8 Shaft, 9 Gap, 10 Around Retainer, 11 d-axis, 12 D-shaped permanent magnet, 13 tile-shaped permanent magnet, 14 axial duct, 15 bar, 16 hole, 17 non-magnetic material, 18 space, 19 wedge, 20 sheave, 21 coupling, 22 bearing, 100 rotating electric machine ,

Claims

A rotating electrical machine having a rotor on the inside and a stator on the outside,
The rotor is
A shaft serving as a rotation axis;
A substantially tubular rotor core fixed to the outer periphery of the shaft;
A plurality of permanent magnets arranged in the circumferential direction on the outer peripheral surface of the rotor core;
Having
In the rotor core,
A pair of convex portions projecting outward at positions sandwiching both end faces of the permanent magnet;
A pair of recesses notched inward or a pair of holes provided inside the rotor core at positions facing both ends of the permanent magnet;
Have
The rotating electric machine characterized in that a width T of the convex portion and a width W of the concave portion or the hole satisfy the following expression.
Width W <width T
In the rotating electrical machine according to claim 1,
The rotating electric machine characterized in that a width T of the convex portion and a width W of the concave portion or the hole satisfy the following expression.
0.25 × width T <width W <width T
In the rotating electrical machine according to claim 1 or 2,
The rotating electric machine according to claim 1, wherein a circumferential end surface of the convex portion is parallel to a d-axis connecting a rotation center of the rotor and a magnetic pole center of the permanent magnet.
In the rotating electrical machine according to any one of claims 1 to 3,
The rotating electric machine characterized in that the protrusion amount Rh of the convex portion in the outer diameter direction and the thickness Mh of the permanent magnet satisfy the following expression.
Rh ≦ 0.5 × Mh
In the rotating electrical machine according to any one of claims 1 to 4,
A rotating electrical machine wherein the outer diameter of the permanent magnet is covered with a nonmagnetic material.
In the rotating electrical machine according to any one of claims 1 to 5,
The stator is
An annular core back,
A plurality of teeth arranged in the circumferential direction on the inner peripheral side of the core back;
A coil formed by winding an electric wire around the teeth;
Teeth coupling material of magnetic material provided on the inner circumferential side from the coil and connecting adjacent teeth in the circumferential direction;
A rotating electric machine comprising:
In the rotating electrical machine according to any one of claims 1 to 6,
A rotating electrical machine, wherein the rotor core is molded by casting.
In the rotating electrical machine according to any one of claims 1 to 7,
A rotating electrical machine characterized in that an axial length of a stator core of the stator is made longer than an axial length of the permanent magnet.
In the rotating electrical machine according to any one of claims 1 to 8,
The rotating electric machine according to claim 1, wherein the permanent magnet has a flat plate shape.
In the rotating electrical machine according to any one of claims 1 to 9,
A rotating electric machine characterized in that a duct for passing cooling air is provided inside the rotor.
In the rotary electric machine according to any one of claims 1 to 10,
The rotating electric machine, wherein the pair of convex portions and the pair of concave portions or the pair of holes are provided for each of the permanent magnets.
A hoisting machine having a sheave around which the main rope of the elevator is wound, and a rotating electric machine connected to the sheave,
The elevator hoisting system according to any one of claims 1 to 11, wherein the rotating electric machine is the rotating electric machine according to any one of claims 1 to 11.