JP2021087231A - Rotor of rotary electric machine - Google Patents

Abstract

To provide a rotor of a rotary electric machine, capable of suppressing wrapping of a magnetic steel sheet structuring a rotor core.SOLUTION: In a rotor core 21, an outer diameter side permanent magnet insertion hole 25 arranged on an outer side of a radial direction while being extended in a shaft direction, and an inner diameter side permanent magnet insertion hole 26 arranged on an inner diameter side from the outer diameter side permanent magnet insertion hole 25 while being extended in the shaft direction are formed in each magnetic pole. In the outer diameter side permanent magnet insertion hole 25, an outer diameter side permanent magnet 27 is inserted, and in the inner diameter side permanent magnet insertion hole 26, an inner diameter side permanent magnet 28 is inserted. On a peripheral direction outer side of the inner diameter side permanent magnet insertion hole 26 in the rotor core 21, flux barriers 29 and 30 are continuously formed. In the rotor core 21, a die-casting hole 31 extended in the shaft direction in a region nipped with the flux barriers 29 and 30 between the adjacent pole magnets is formed. A magnetic steel sheet 22 is fixed by a pure aluminum 32 filled into the die-casting hole 31.SELECTED DRAWING: Figure 5

Description

The present invention relates to a rotor of a rotary electric machine.

Patent Document 1 and the like disclose a permanent magnet embedded rotary electric machine. Specifically, the outer peripheral surfaces of the cylindrical rotor cores are arranged so as to face each other on the inner peripheral side of the stator wound with the coil, and a plurality of permanent magnets are embedded in the rotor core in which the electromagnetic steel sheets are laminated in the radial direction.

Japanese Patent No. 6020629

By the way, in the rotor of a rotary electric machine, a shaft is inserted in the center of a rotor core formed by laminating electromagnetic steel plates. For example, when the shaft and the rotor core are shrink-fitted and fastened, the rotation speed becomes high. Warpage may occur in the electromagnetic steel sheets that make up the rotor core.

An object of the present invention is to provide a rotor of a rotary electric machine capable of suppressing warpage of an electromagnetic steel plate constituting a rotor core.

The rotor of the rotary electric machine for solving the above problems is a rotor of the rotary electric machine arranged so that the outer peripheral surfaces of the cylindrical rotor cores face each other on the inner peripheral side of the stator wound with the coil, and the rotor core is The rotor core is formed by laminating electromagnetic steel plates, and the shaft is inserted in the center. The rotor core has an outer diameter side permanent magnet insertion hole that extends in the axial direction and is arranged on the outer side in the radial direction, and extends in the axial direction and is described above. An inner diameter side permanent magnet insertion hole arranged on the inner diameter side of the outer diameter side permanent magnet insertion hole is formed for each magnetic pole, and the outer diameter side permanent magnet is inserted into the outer diameter side permanent magnet insertion hole and the inner diameter side is inserted. An inner diameter side permanent magnet is inserted into the side permanent magnet insertion hole, and a flux barrier is continuously formed on the outer side in the circumferential direction of the inner diameter side permanent magnet insertion hole in the rotor core, and the flux barrier is formed between adjacent magnetic poles in the rotor core. The gist is that a filling hole extending in the axial direction is formed in the sandwiched region, and the electromagnetic steel plate is fixed by a non-magnetic metal or resin filled in the filling hole.

According to this, the filling hole extends in the axial direction in the region sandwiched by the flux barrier between the adjacent magnetic poles in the rotor core, and the magnetic steel sheet is fixed by the non-magnetic metal or resin filled in the filling hole. Therefore, the electromagnetic steel sheet constituting the rotor core can be firmly fixed and the warp of the electromagnetic steel sheet constituting the rotor core can be suppressed.

Further, in the rotor of the rotary electric machine, the outer diameter side permanent magnet insertion hole and the inner diameter side permanent magnet insertion hole at each of the magnetic poles may have an arc shape.
It is particularly useful when the outer diameter side permanent magnet insertion hole and the inner diameter side permanent magnet insertion hole form an arc shape.

Further, in the rotor of the rotary electric machine, a filling hole extending in the axial direction is further formed so as to be separated from the outside in the circumferential direction of the flux barrier in the rotor core, and the electromagnetic steel sheet is formed of a non-magnetic metal or resin filled in the filling hole. It should be fixed.

In this case, the electromagnetic steel sheet constituting the rotor core can be more firmly fixed, and the warpage of the electromagnetic steel sheet constituting the rotor core can be further suppressed.

According to the present invention, it is possible to suppress the warp of the electromagnetic steel sheet constituting the rotor core.

The schematic diagram of the rotary electric machine in an embodiment. A perspective view of the rotor and the shaft. An exploded perspective view of the rotor and shaft. Front view of rotor and shaft. FIG. 4 is a cross-sectional view taken along the line AA of FIG. Perspective view of the rotor and shaft in vertical section. FIG. 3 is a perspective view of a rotor core and a shaft without a holding portion and a lid member. The perspective view of the rotor core and the shaft in the vertical section without the holding part and the lid member.

Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings.
As shown in FIG. 1, the rotary electric machine 10 is a permanent magnet embedded type synchronous motor, and includes a rotor (rotor) 20 and a stator (stator) 100. The stator 100 is arranged on the outer peripheral side of the cylindrical rotor 20. The inner peripheral surface of the stator 100 faces the outer peripheral surface of the rotor 20 via a gap. All of the figures are schematic views, and the shapes are emphasized. The rotary electric machine 10 has a number of poles of "4", and permanent magnets are arranged at 90 ° intervals in the circumferential direction.

As shown in FIG. 1, in the stator 100, the stator core 101 has a cylindrical shape, and a plurality of slots 102 are formed inside the stator core 101 in the circumferential direction. Each slot 102 is open to the inner peripheral surface. Teeth 103 are formed between the slots 102. A coil (winding) 104 is wound around the tooth 103. As described above, the stator 100 has a configuration in which the teeth 103 around which the coil 104 is wound are arranged side by side in the circumferential direction and the coil 104 is wound around the stator 100.

A rotor 20 is arranged inside the stator 100, and the rotor 20 includes a cylindrical rotor core 21 in which a plurality of (for example, several tens) substantially disk-shaped electromagnetic steel sheets 22 are laminated. In the rotor core 21, laminated electromagnetic steel sheets 22 are connected by dowel caulking.

The rotor 20 is rotatably supported by a bearing of a housing (not shown) via a shaft 50 in a state where the outer peripheral surface of the rotor core 21 is spaced apart from the teeth 103 at a predetermined distance. In this way, the rotor 20 is arranged on the inner peripheral side of the stator 100 so that the outer peripheral surfaces of the rotor core 21 face each other with a gap.

As shown in FIGS. 2, 4, and 7, the shaft 50 is inserted into the center of the rotor core 21 formed by laminating the electromagnetic steel sheets 22. The rotor core 21 is fitted and fastened to the shaft 50 by shrink fitting (or press fitting or the like). As shown in FIG. 5, the rotor core 21 has an outer diameter side permanent magnet insertion hole 25, an inner diameter side permanent magnet insertion hole 26, flux barriers 29, 30, 37, 38, and die casting holes 31, 33, 35.

As shown in FIGS. 5, 7, and 8, the rotor core 21 has an outer diameter side permanent magnet insertion hole 25 extending in the axial direction and arranged radially outside, and an outer diameter side permanent magnet extending in the axial direction. An inner diameter side permanent magnet insertion hole 26 arranged on the inner diameter side of the insertion hole 25 is formed for each magnetic pole. The outer diameter side permanent magnet insertion hole 25 and the inner diameter side permanent magnet insertion hole 26 at each magnetic pole have an arc shape. Specifically, as shown in FIG. 5, the outer diameter side permanent magnet insertion hole 25 and the inner diameter side permanent magnet insertion hole 26 have an arc shape with the center side of the rotor core 21 convex (centered on the outer diameter side of the rotor core 21). Is doing.

As shown in FIGS. 2, 3, 4, and 6, in the rotor core 21, on both sides of a laminated body of electrical steel sheets 22 having an outer diameter side permanent magnet insertion hole 25 and an inner diameter side permanent magnet insertion hole 26. It has lid members 23a and 23b. The outer diameter side permanent magnet insertion holes 25 and the inner diameter side permanent magnet insertion holes 26 are not formed in the lid members 23a and 23b. As shown in 4, 5 and 6, aluminum can be injected by aluminum die casting. The lid members 23a and 23b have holding portions 24a and 24b on both sides thereof. The sandwiching portions 24a and 24b are made of pure aluminum and are formed by aluminum die casting as shown in FIGS. 4 and 6 from the state shown in FIGS. 7 and 8.

As shown in FIG. 6, the outer diameter side permanent magnet 27 is inserted into the outer diameter side permanent magnet insertion hole 25, and the inner diameter side permanent magnet 28 is inserted into the inner diameter side permanent magnet insertion hole 26. The outer diameter side permanent magnet 27 is adhesively fixed to the outer diameter side permanent magnet insertion hole 25. The inner diameter side permanent magnet 28 is adhesively fixed to the inner diameter side permanent magnet insertion hole 26.

As shown in FIG. 6, the outer diameter side permanent magnets 27 are arranged in a state of being divided in the axial direction. The inner diameter side permanent magnets 28 are arranged in a state of being divided in the axial direction. By using permanent magnets divided in the axial direction, loss can be reduced and economic efficiency can be improved.

As shown in FIG. 5, each of the embedded permanent magnets 27 and 28 has an arc shape. The permanent magnet 27 is located on the d-axis, and the permanent magnet 27 is magnetized in the thickness direction. The permanent magnet 28 is located on the d-axis, and the permanent magnet 28 is magnetized in the thickness direction. The permanent magnets 27 and the permanent magnets 28 arranged in adjacent regions (one pole) are arranged so that the outer peripheral sides of the rotor 20 have different poles. For example, when a certain permanent magnet 27 is arranged so that the teeth 103 side has an S pole, the permanent magnet 27 arranged in the adjacent region (one pole) is arranged so that the teeth 103 side has an north pole. ..

As shown in FIGS. 5 and 7, a flux barrier 29 is continuously formed on the outer side of one of the inner diameter side permanent magnet insertion holes 26 in the rotor core 21 in the circumferential direction. Further, a flux barrier 30 is continuously formed on the outer side of the other peripheral direction of the inner diameter side permanent magnet insertion hole 26 in the rotor core 21. The flux barriers 29 and 30 have an arc shape.

A die-cast hole 31 as a filling hole extending in the axial direction is formed in a region sandwiched between the flux barriers 29 and 30 between adjacent magnetic poles in the rotor core 21. The die-cast hole 31 is filled with pure aluminum 32 as a non-magnetic metal. The electromagnetic steel sheet 22 is fixed by the pure aluminum 32 filled in the die-cast hole 31. The pure aluminum 32 filled in the die-cast hole 31 is made of aluminum die-cast as shown in FIGS. 4, 5 and 6 from the state shown in FIGS. 7 and 8.

A die-cast hole 33 is formed as a filling hole extending in the axial direction separated from the outside of the flux barrier 29 in the circumferential direction of the rotor core 21. Further, a die-cast hole 35 is formed as a filling hole extending in the axial direction separated from the outside of the flux barrier 30 in the circumferential direction of the rotor core 21. The die-cast hole 33 is filled with pure aluminum 34 as a non-magnetic metal. The die-cast hole 35 is filled with pure aluminum 36 as a non-magnetic metal. The electromagnetic steel sheet 22 is fixed by the pure aluminum 34, 36 filled in the die-cast holes 33, 35. The pure aluminum 34, 36 filled in the die-cast holes 33, 35 is made of aluminum die-cast as shown in FIGS. 4, 5 and 6 from the state shown in FIGS. 7 and 8.

Flux barriers 37 and 38 (see FIG. 5) are continuously formed on the outer side of the outer diameter side permanent magnet insertion hole 25 in the rotor core 21 in the circumferential direction. The flux barriers 37 and 38 have an arc shape.

Next, the operation of the rotary electric machine 10 configured in this way will be described.
When the rotary electric machine is driven, a current is supplied to the coil 104 of the stator 100 to generate a rotating magnetic field in the stator 100, and the rotating magnetic field acts on the rotor 20. Then, the rotor 20 rotates in synchronization with the rotating magnetic field due to the magnetic attraction and repulsion between the rotating magnetic field and the permanent magnets 27 and 28.

The die-cast hole 31 extends in the axial direction in the region sandwiched between the flux barriers 29 and 30 between the adjacent magnetic poles in the rotor core 21, and the electromagnetic steel plate 22 is fixed by the pure aluminum 32 filled in the die-cast hole 31. .. As a result, the electromagnetic steel sheet 22 constituting the rotor core 21 is firmly fixed, and the warp of the electromagnetic steel sheet 22 constituting the rotor core 21 is suppressed. In other words, in the substantially inverted arc-shaped two-layer magnet arrangement rotor cross-sectional shape, both performance and strength are achieved by arranging die-cast holes between the magnetic poles that are sandwiched between the flux barriers and are not affected by the shrink fitting fastening force. A rotor structure is realized.

The details will be described below.
The length of the permanent magnet insertion hole on the inner diameter side tends to increase, and the balance between performance and strength is insufficient. Specifically, the electromagnetic steel sheet tends to turn up due to centrifugal force, and when bending stress is applied to the thin-walled bridge, the strength becomes stronger. The drop is large. In this case, adding a thick non-magnetic end plate to the end of the rotor as a measure against the strength of the rotor core causes an increase in cost. That is, when the permanent magnets are arranged in two layers on the outer diameter side and the inner diameter side, the fitting fastening force between the rotor core and the shaft is reduced due to the internal stress due to the shrink fitting of the shaft, which warps in the direction perpendicular to the cross section. When a rigid end plate is arranged and fixed on the rotor end face in order to suppress this warpage, the manufacturing cost increases due to the cost increase due to the rigid end plate and the fixing means (screws, caulking, etc.).

In this embodiment, die casting technology and equipment are used when the induction motor manufacturing equipment can be used. The fixing means by aluminum die casting has a structure that can be constructed at low cost by minimizing new capital investment when the equipment for manufacturing the induction motor is already owned. Further, by die-casting, a rigid end plate and end plate fixing means are not required, and the cost of parts can be reduced.

A general aluminum die cast uses a strong and robust material such as ADC12, but in order to construct it inexpensively without requiring additional capital investment, it is made of pure aluminum, which is the same material used for manufacturing induction motors. It is configured.

Here, when pure aluminum is used to improve the rigidity of the rotor structure, it is important to arrange the die-cast holes that communicate with the rotor core cross section. Even though it is a synchronous motor, if the die-cast hole is arranged at an inappropriate position due to the alternating magnetic field from the stator, an induced current may be generated, which may adversely affect the performance such as output reduction. Therefore, it is necessary to carefully consider the effect of arranging the die-cast holes near the outer periphery of the cross section of the rotor core, and the rotor core and shaft are shrink-fitted and fixed to reduce costs, and the die-cast holes are arranged on the inner peripheral side. If it is installed, it may adversely affect the strength such as a decrease in shrinkage fastening force. That is, in the rotor of an electric motor in which a permanent magnet is embedded in the rotor core, a die-cast hole cannot be formed because the vicinity of the permanent magnet is a magnetic path, and the inner diameter side of the rotor core is a region used for shrink fitting. Therefore, it is not possible to form a die-cast hole.

In the present embodiment, the die-cast hole 31 is formed in the region sandwiched between the flux barriers 29 and 30 between the adjacent magnetic poles, which is a portion closer to the inner diameter between the magnetic poles, and the q-axis magnetic flux constituting the magnetic circuit of the rotor core is formed. It does not interfere with the shrink fit fastening strength of the shaft on the inner diameter side. The formation position of the die-cast hole is preferably a place that does not obstruct the q-axis magnetic path between the magnetic poles, that is, a place where the magnetic flux density in the rotor core is not high, and after the left and right magnetic flux branches in the q-axis magnetic flux from the outer diameter side to the inner diameter side. It is a place between. As a result, the q-axis magnetic flux of the rotor core is not hindered, and the shrink fit of the shaft on the inner diameter side is not hindered.

In this way, the strength is improved when the shaft is shrink-fitted into the rotor core. When manufacturing the rotor 20, the electromagnetic steel sheets 22 are laminated and arranged, and one lid member 23a is laminated and arranged on one end surface of the electromagnetic steel sheet laminated body. Then, after inserting the permanent magnets 27 and 28 and further arranging the other lid member 23b, they are fixed by caulking and fixed by die casting with pure aluminum 32, 34, 36 in the die casting holes 31, 33, 35.

Therefore, the electrical steel sheet is easily warped by shrink fitting during manufacturing and is easily warped by the centrifugal force when the rotation speed is increased during normal operation, but in the present embodiment, the warpage of the electrical steel sheet can be suppressed.

According to the above embodiment, the following effects can be obtained.
(1) As a configuration of the rotor 20 of the rotary electric machine 10 arranged so that the outer peripheral surfaces of the cylindrical rotor core 21 face each other on the inner peripheral side of the stator 100 around which the coil 104 is wound, the rotor core 21 is made of an electromagnetic steel plate 22. It is constructed by laminating, and the shaft 50 is inserted in the center. The rotor core 21 has an outer diameter side permanent magnet insertion hole 25 extending in the axial direction and arranged radially outside, and an inner diameter side extending axially and arranged on the inner diameter side of the outer diameter side permanent magnet insertion hole 25. A permanent magnet insertion hole 26 is formed for each magnetic pole. The outer diameter side permanent magnet 27 is inserted into the outer diameter side permanent magnet insertion hole 25, and the inner diameter side permanent magnet 28 is inserted into the inner diameter side permanent magnet insertion hole 26. Flux barriers 29 and 30 are continuously formed on the outer side of the inner diameter side permanent magnet insertion hole 26 in the circumferential direction of the rotor core 21. A die-cast hole 31 as a filling hole extending in the axial direction is formed in a region sandwiched between the flux barriers 29 and 30 between adjacent magnetic poles in the rotor core 21, and the die-cast hole 31 is filled with pure aluminum 32 as a non-magnetic metal. The electromagnetic steel plate 22 is fixed.

Therefore, the die casting hole 31 extends in the axial direction in the region sandwiched between the flux barriers 29 and 30 between the adjacent magnetic poles in the rotor core 21, and the electrical steel sheet 22 is fixed by the pure aluminum 32 filled in the die casting hole 31. Therefore, the electromagnetic steel plate 22 constituting the rotor core 21 can be firmly fixed to suppress the warp of the electromagnetic steel plate 22 constituting the rotor core 21.

(2) The outer diameter side permanent magnet insertion hole 25 and the inner diameter side permanent magnet insertion hole 26 at each magnetic pole have an arc shape. It is particularly useful when the outer diameter side permanent magnet insertion hole 25 and the inner diameter side permanent magnet insertion hole 26 form an arc shape.

(3) Die-cast holes 33, 35 as filling holes extending in the axial direction separated from the outside of the flux barriers 29, 30 in the rotor core 21 in the circumferential direction are further formed, and as a non-magnetic metal filled in the die-cast holes 33, 35. The electromagnetic steel plate 22 is fixed by the pure aluminum 34 and 36 of the above. In this case, the electromagnetic steel sheet 22 constituting the rotor core 21 can be further firmly fixed, and the warpage of the electromagnetic steel sheet 22 constituting the rotor core 21 can be further suppressed.

The embodiment is not limited to the above, and may be embodied as follows, for example.
○ The non-magnetic metal was pure aluminum, but it is not limited to this. As the non-magnetic metal, an aluminum alloy such as ADC12 or copper may be used. Further, a resin may be used in addition to the non-magnetic metal, and the resin may be molded.

That is, by using the above-mentioned die-cast hole 31 as a resin mold hole and the above-mentioned pure aluminum 32 as a resin, the rotor core 21 is filled in the region sandwiched between the flux barriers 29 and 30 between the adjacent magnetic poles in the axial direction. The pores are formed, and the electromagnetic steel plate 22 is fixed by the resin filled in the filled holes. Further, by using the above-mentioned die-cast holes 33 and 35 as resin mold holes and the above-mentioned pure aluminum 34 and 36 as resin, the flux barriers 29 and 30 in the rotor core 21 are separated from each other in the circumferential direction and extend in the axial direction. The filling holes are further formed, and the electromagnetic steel plate 22 is fixed by the resin filled in the filling holes.

○ The die-cast holes 33 and 35 may be omitted, and for example, a flux barrier may be used instead.
○ The number of poles is not limited to 4 poles. It may be more or less than 4 poles.

○ The permanent magnet may be V-shaped instead of arc-shaped.
○ The motor may be other than a synchronous motor, in short, it may be a permanent magnet embedded motor.

10 ... Rotating machine, 20 ... Rotor, 21 ... Rotor core, 22 ... Electromagnetic steel plate, 25 ... Outer diameter side permanent magnet insertion hole, 26 ... Inner diameter side permanent magnet insertion hole, 27 ... Outer diameter side permanent magnet, 28 ... Inner diameter side permanent Magnet, 29, 30 ... Flux barrier, 31 ... Die cast hole, 32 ... Pure aluminum, 33 ... Die cast hole, 34 ... Pure aluminum, 35 ... Die cast hole, 36 ... Pure aluminum, 50 ... Shaft, 100 ... Stator, 104 ... Coil ..

Claims (3)

A rotor of a rotary electric machine arranged so that the outer peripheral surfaces of a cylindrical rotor core face each other on the inner peripheral side of a stator wound with a coil.
The rotor core is formed by laminating electromagnetic steel sheets, and a shaft is inserted in the center.
The rotor core has an outer diameter side permanent magnet insertion hole that extends in the axial direction and is arranged radially outside, and an inner diameter side permanent that extends in the axial direction and is arranged on the inner diameter side of the outer diameter side permanent magnet insertion hole. A magnet insertion hole is formed for each magnetic pole,
The outer diameter side permanent magnet is inserted into the outer diameter side permanent magnet insertion hole, and the inner diameter side permanent magnet is inserted into the inner diameter side permanent magnet insertion hole.
A flux barrier is continuously formed on the outer side of the inner diameter side permanent magnet insertion hole in the rotor core in the circumferential direction.
A filling hole extending in the axial direction is formed in a region sandwiched between the flux barriers between adjacent magnetic poles in the rotor core, and the electromagnetic steel sheet is fixed by a non-magnetic metal or resin filled in the filling hole. A characteristic rotary electric rotor. The rotor of a rotary electric machine according to claim 1, wherein the outer diameter side permanent magnet insertion hole and the inner diameter side permanent magnet insertion hole in each of the magnetic poles have an arc shape. A feature of the rotor core is that a filling hole extending in the axial direction is further formed apart from the outside of the flux barrier in the circumferential direction, and the electromagnetic steel sheet is fixed by a non-magnetic metal or resin filled in the filling hole. The rotor of the rotary electric machine according to claim 2.

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