JP2014023265A - Rotor of permanent magnet type rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a built-up structure of a rotor so as to enable easy loading of a permanent magnet to a magnet insertion slot formed in a rotor core, and secure a cooling ventilation flue demarcated between iron core blocks of the rotor.SOLUTION: In an embedded magnet type permanent magnet type rotary electric machine formed by dividing a rotary core 3 which is a laminate of magnetic steel sheets into a plurality of iron core blocks 3a in an axial direction, demarcating ventilation gaps 6 allowing cooling air to flow between the mutual iron core blocks, and fitting and inserting magnet units 7 which are aggregates of permanent magnet pieces 8 divided into plural pieces into magnet insertion slots 5 drilled in an axial direction in each iron core block 3a, the magnet unit 7 is constituted by an assembly in which the divided magnet pieces 8 arranged in accordance with the arrangement of the iron core blocks of the rotor and the ventilation gaps are held by coupling plates 9 of magnetic material from above and below and integrally bonded, cooling air ventilation holes 9a are drilled on plate surfaces of the coupling plates 9 in accordance with the arrangement pitch of the ventilation gaps 6, and the cooling air is allowed to freely flow between the iron core blocks without being blocked by the magnet pieces.

Description

  The present invention relates to an assembly structure of a rotor in an interior magnet type permanent magnet rotating electric machine (IPM (Interior Permanent Magnet Motor)).

  As is well known, an embedded magnet type permanent magnet type rotating electrical machine has a magnet insertion slot that penetrates the iron core in the axial direction by allocating it in the circumferential direction of the rotor iron core that is a laminate of electromagnetic steel sheets. In addition, a permanent magnet is inserted into the magnet insertion slot and fixed.

  This permanent magnet is divided into a plurality of permanent magnet pieces in order to reduce eddy current loss caused by an alternating magnetic field applied from the stator side, and a permanent magnet having a divided structure in which these are electrically insulated from each other. It is publicly known (see, for example, Patent Document 1).

  In addition, in order to facilitate the assembling work when the permanent magnet having a split structure (see Patent Document 1) is loaded in the magnet insertion slot formed in the rotor core in the assembly process of the permanent magnet type rotating electrical machine described above, Permanent magnet type rotation that consists of a magnet unit in which divided magnet pieces are housed in a case made of non-magnetic material and assembled together for each magnetic pole, and this magnet unit is inserted into the magnet insertion slot of the rotor core. An electric rotor is known (for example, see Patent Document 2).

  On the other hand, as the air cooling structure of a rotating electrical machine, the stator and rotor core are divided into a plurality of core blocks in the axial direction, and a ventilation gap is formed to allow cooling air to flow between the core blocks. Conventionally, a structure in which a cooling air guided from the inner peripheral side of the rotor core is allowed to flow through the ventilation gap to cool the stator and the rotor has been conventionally employed (see, for example, Patent Document 3). .

Japanese Patent Laid-Open No. 2003-164083 JP 2001-16808 A Japanese Utility Model Publication No. 55-109-50650

  By the way, when the magnet unit disclosed in Patent Document 2 is adopted in the rotor of a rotating electrical machine having the air cooling structure of Patent Document 3, the ventilation path of the ventilation gap defined between the iron core blocks of the rotor is a magnet. There is a problem that the cooling of the rotating electrical machine is deteriorated due to obstruction of the flow of the cooling air through the ventilation gap defined between the iron core blocks. In the embodiment of FIG. 2 in Patent Document 2, a nonmagnetic spacer is interposed between the divided magnet pieces accommodated in the case of the magnet unit corresponding to the ventilation gap between the iron core blocks. Since the magnetic spacer is the same length as the segmented magnet piece and the upper and lower sides are covered with the case, the ventilation path between the iron core blocks must be blocked when this magnet unit is loaded in the magnet insertion slot of the rotor. There is no change.

  The present invention has been made in view of the above points, and its object is to solve the above problems and facilitate the operation of loading permanent magnets into the magnet insertion slots formed in the rotor core, and between the core blocks of the rotor. Another object of the present invention is to provide a rotor of an embedded magnet type permanent magnet type rotating electrical machine having an improved assembly structure of a magnet unit so that a cooling ventilation path can be secured.

In order to achieve the above object, according to the present invention, a rotor core composed of a laminate of electromagnetic steel sheets is divided into a plurality of core blocks in the axial direction, and magnets are inserted through the core blocks in the axial direction. An embedded magnet type in which a slot is formed, a ventilation gap is defined between each iron core block, and a magnet unit that is an assembly of a plurality of divided permanent magnet pieces is inserted into the magnet insertion slot. In the permanent magnet type rotating electrical machine,
A magnet unit, which is an assembly in which a plurality of segmented magnet pieces are collectively held by a connecting plate and bonded, is inserted into the magnet insertion slot, and vent holes are formed in the connecting plate in accordance with the arrangement pitch of the ventilation gaps. The magnet unit can be specifically configured in the following manner.
(1) A magnet unit is configured by interposing a short non-magnetic spacer between the segmented magnet pieces arranged in the axial direction with a gap therebetween, and integrally combining with a connecting plate.
(3) A rib-like protrusion for positioning and holding the segmented magnet piece is formed on the opening side edge of the ventilation hole formed in the connecting plate of the magnet unit.
(4) The coupling plate of the magnet unit is made of a magnetic material.

  In the assembled state of the rotor in which the magnet unit configured as described above is inserted into the magnet insertion slot of the rotor core that is a laminate of electromagnetic steel plates and fixedly held at a predetermined position, a ventilation hole formed in the connecting plate of the magnet unit, In addition, a cooling air passage can be secured between the iron core blocks of the rotor through the mutual gap between the divided magnet pieces sandwiched between the connecting plates, and thereby the air cooling performance of the rotating electrical machine can be sufficiently exhibited.

  3. The structure according to claim 2, wherein a short non-magnetic spacer is interposed between the divided magnet pieces arranged in the axial direction with a gap serving as a ventilation path, or connected in place of the spacer. According to the configuration of claim 3, the rib-like projections for positioning and holding the divided magnet pieces are formed on the opening side edge of the vent hole formed in the plate surface of the plate. The divided magnet pieces sandwiched between the connecting plates can be easily positioned. Therefore, a cooling air passage leading to the air gap between the iron core blocks can be set.

  Moreover, by making the said connection piece into a magnetic body, it can be functioned as a common magnetic pole plate of each division | segmentation magnet piece which divided this connection plate and arranged in plurality.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an assembly structure diagram of a rotor according to an embodiment of the present invention, where (a) is a perspective view showing an assembled state before the magnet unit is inserted into the rotor core, and (b) is an exploded perspective view of the magnet unit. is there. FIG. 2 is a side cross-sectional view showing a cooling air ventilation path in the assembled state of FIG. It is a disassembled perspective view of the magnet unit concerning Example 2 of this invention. It is a disassembled perspective view of the magnet unit concerning Example 3 of this invention.

  Embodiments of the present invention will be described below based on the examples shown in FIGS.

  First, FIGS. 1A, 1B, and 2 show a basic rotor assembly structure according to the present invention. In each figure, 1 is a rotor, 2 is a rotary shaft, 3 is a rotor core fixed to the rotary shaft 2 by being fitted to an arm 2a projecting radially from the rotary shaft 2, and 3a is an iron core block of the rotor core 3. 5 is a magnet insertion slot formed in the rotor core 3, 6 is a ventilation gap defined between the core blocks 3 a, 7 is a permanent magnet magnet unit that is inserted into the magnet insertion slot 5, and 8 is permanent. Reference numeral 9 is a connecting plate in which a plurality of divided magnet pieces 8 are clamped and bonded together from above and below, and 9 a is a ventilation hole formed in the plate surface of the connecting plate 9.

  Here, the rotor iron core 3 has iron core blocks 3a that are laminated of electromagnetic steel sheets arranged in the axial direction, and a ventilation air passage is provided between the iron core blocks 3a via a spacer 10 (see FIG. 2). A gap 7 is defined, and a magnet insertion slot 5 is formed in the vicinity of the outer periphery of the core so as to penetrate each core block 3a in the axial direction and be assigned in the circumferential direction. In the magnet insertion slot 5, a magnet unit 7 that is an assembly of a plurality of divided permanent magnet pieces is fitted and arranged. Next, the detailed structure of the magnet unit 7 is shown in FIG. I will explain it.

  In other words, the magnet unit 7 has a plurality of divided magnet pieces 8 as shown in the drawing aligned with the arrangement of the iron core blocks 3a, and with an interval corresponding to the width t of the ventilation gap 6 therebetween. The divided magnet pieces 8 are composed of an assembly in which the divided magnet pieces 8 are sandwiched and bonded together by a thin connecting plate 9 which is a magnetic body from above and below, and the arrangement pitch of the ventilation gaps 6 on the plate surface of the connecting plate 9 is A slit-shaped ventilation hole 9a is formed in accordance with the width t of the gap.

  In the assembly process of the rotor, the magnet unit 7 having the above-described configuration is inserted into the magnet insertion slot 5 formed in the rotor core 3 and fixed in place. In this case, the assembly of the divided magnet pieces 8 can be easily inserted into the magnet insertion slot 5 using the connecting plate 9 of the magnet unit 7 as an insertion guide.

  When the cooling air is blown from the inner peripheral side of the rotor core 3 as shown by the arrow in the assembled state of the rotor 1 shown in FIG. 2, the air is pushed into the ventilation gap 6 defined between the block cores 3a. The blown cooling air freely flows through the ventilation holes 9 a opened in the connecting plate 9 of the magnet unit 7 and the mutual gap between the divided magnet pieces 8. Accordingly, the rotating electrical machine is effective by passing the cooling air through the ventilation gap 6 defined between the iron core blocks 6 of the rotor core 3 without being obstructed by the magnet unit 7 inserted in the magnet insertion slot 5. Can be cooled. Further, the connecting plate 9 that becomes a magnetic body functions as a common magnetic pole plate for the plurality of divided magnet pieces 8.

  Next, an application example in which the assembly structure of the magnet unit 7 is improved will be described with reference to FIGS.

  FIG. 3 is a configuration diagram of a magnet unit 7 corresponding to claim 2 of the present invention, with a short piece of nonmagnetic spacer 11 serving as a prism block interposed between divided magnet pieces 8 as shown in the figure, The connecting plates 9 similar to those of the first embodiment are overlapped and bonded together. Thereby, each divided magnet piece 8 can be easily positioned and set, and in the assembled state of the magnet unit 7, a ventilation gap connected to the ventilation hole 9 a of the connecting plate 9 is secured between the divided magnet pieces 8. In addition, since the spacer 11 is made of a nonmagnetic material, the leakage magnetic flux between the adjacent divided magnet pieces 8 can be kept low.

  FIG. 4 is a block diagram of a magnet unit 7 corresponding to claim 3 of the present invention. In this embodiment, a rib shape protruding toward the divided magnet piece 8 along the side edge of the ventilation hole 9a formed in the connecting plate 9 is shown. The protrusion 9b is cut and raised. When the magnet unit 7 is assembled, the split magnet piece 8 sandwiched between the upper and lower connecting plates 9 is fitted between the rib-shaped projections 9b using the rib-shaped projections 9b as positioning guides and held at a predetermined position. As a result, the magnet unit 7 can be assembled by simply positioning the divided magnet pieces 8 in the same manner as the spacer 11 of the second embodiment.

DESCRIPTION OF SYMBOLS 1 Rotor 2 Rotating shaft 2a Rotating shaft arm 3 Rotor core 3a Iron block 5 Magnet insertion slot 6 Ventilation gap 7 Magnet unit 8 Divided magnet piece 9 Connecting plate 9a Ventilation hole 9b Rib-shaped protrusion 11 Nonmagnetic spacer

Claims (4)

A rotor core made of a laminate of electromagnetic steel sheets is divided into a plurality of core blocks in the axial direction, and a magnet insertion slot is formed through each core block in the axial direction, and ventilation is provided between the core blocks. In an embedded magnet type permanent magnet type rotating electrical machine in which a gap is defined and a permanent magnet piece is inserted into the magnet insertion slot,
A magnet unit, which is an assembly in which a plurality of divided magnet pieces are collectively sandwiched and bonded by a connecting plate, is fitted into the magnet insertion slot, and the plate surface of the connecting plate is ventilated according to the arrangement pitch of the ventilation gaps. A rotor of a permanent magnet type rotating electrical machine, wherein a hole is formed.   The rotor according to claim 1, wherein a short non-magnetic spacer is interposed between the divided magnet pieces arranged in the axial direction with a gap between them, and a magnet unit is configured by integrally combining with a connecting plate. A rotor of a permanent magnet type rotating electrical machine.   The rotor according to claim 1, wherein a rib-like protrusion for positioning and holding the divided magnet piece is formed on the opening side edge of the ventilation hole formed in the connecting plate of the magnet unit. Rotor.   The rotor according to any one of claims 1 to 3, wherein the coupling plate is a magnetic body.

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