JP2017060274A - Permanent magnet rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a permanent magnet rotary electric machine that is small in cogging torque even in use of a bond magnet containing rare earth.SOLUTION: A permanent magnet rotary electric machine comprises: a stator in which armature coils 9 are wound around teeth 5 in a concentrated manner in a plurality of slots 7 formed in a stator iron core 4; a rotor cup 10 born on the outer periphery of the stator via a predetermined gap so as to freely rotate; and a rotor in which magnetized permanent magnets 12 are arranged substantially at equal intervals in the rotor cup. If the number of teeth of the stator iron core is M and the number of permanent magnets is P, they are formed so as to satisfy the relation expressed by P:M=6n±2:6n (in which n is an integer of 2 or greater). The permanent magnet is configured such that an SmFeN bond magnet containing rare earth is partially arranged on the inner periphery side of the rotor cup. The length of the SmFeN bond magnet is made greater than the product thickness of the stator iron core, and an auxiliary groove 13 and a beveling 14 are formed on the inner periphery surface of the SmFeN bond magnet.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a permanent magnet rotating electric machine that employs a concentrated winding stator, and in particular, in order to reduce cogging torque, when the number of teeth of the stator core is M and the number of permanent magnets is P, P: M = The present invention relates to an improvement of a permanent magnet rotating electrical machine formed in a relationship of 6n ± 2: 6n (where n is an integer of 2 or more).

  It is well known that the cogging torque of a permanent magnet rotating electric machine that employs a concentrated winding stator is inversely proportional to the least common multiple of the number M of teeth of the stator core and the number P of permanent magnets. In a general 2-pole 3-slot (same as 3 teeth) series (4-pole 6-slot, 8-pole 12-slot...), The least common multiple is as small as 6 (2 × 3), so the cogging torque increases. As a countermeasure against this, as shown in Patent Document 1, Patent Document 2, and Patent Document 3, a method of providing two recesses on the teeth surface of the stator core on the inner peripheral side of the outer rotor (Patent Document 1). And a non-magnetized region of two locations on the surface of a permanent magnet opposed to the three-phase drive coil and the axial direction for a 4-pole 3-slot series brushless motor (see Patent Document 2), There has been proposed a system (see Patent Document 3) in which a permanent magnet formed on an adder-type rotor is composed of a bonded magnet and a groove is provided on the outer peripheral surface thereof.

Japanese Patent Publication No. 2008-148469 Japanese Unexamined Patent Publication No. 64-5345 JP-A-2015-146713

  In the prior art described in Patent Document 1, Patent Document 2, and Patent Document 3, in a permanent magnet rotating electrical machine of 2-pole 3-slot series or 4-pole 3-slot series (3-air coil), a tooth head or a cylindrical magnet Cogging torque can be reduced by providing auxiliary grooves on the outer peripheral surface.

  In contrast, in the 10 pole 12 slot or 14 pole 12 slot series, the least common multiple is as large as 30 (5 × 6) and 42 (7 × 6), so the cogging torque is small. However, when the number of teeth of the stator core is M and the number of permanent magnets is P, the permanent is formed in the relationship of P: M = 6n ± 2: 6n (where n is an integer of 2 or more). In a magnet rotating electrical machine, when an SmFeN bonded magnet containing rare earth was used, the cogging torque was increased, and as a result, vibration and noise were increased.

  The present invention has been made in view of this, and the object of the present invention is that when M is the number of teeth of the stator core and P is the number of permanent magnets, P: M = 6n ± 2: 6n (however, n Is a permanent magnet rotating electrical machine formed in a relationship of an integer of 2 or more), and provides a permanent magnet rotating electrical machine having a small cogging torque even when a bonded magnet containing a rare earth is used.

  A second object of the present invention is to provide a permanent magnet rotating electric machine that reduces leakage current from the armature winding and has high reliability in the permanent magnet rotating electric machine.

  In order to solve the above-described object, the present invention provides a multi-phase (U, V, W phase) armature that is concentratedly wound so as to surround teeth in a plurality of slots formed in a stator core. A stator provided with windings, a rotor cup rotatably supported on the outer periphery of the stator via a predetermined gap, and a rotor having permanent magnets magnetized at substantially equal intervals on the rotor cup; A permanent magnet rotating electrical machine formed in a relationship of P: M = 6n ± 2: 6n (where n is an integer of 2 or more) where M is the number of teeth of the stator core and P is the number of permanent magnets The SmFeN bonded magnet containing a rare earth in the permanent magnet is partially arranged on the inner peripheral side of the rotor cup, and the length of the SmFeN bonded magnet is made longer than the thickness of the stator core. Auxiliary grooves are formed on the inner peripheral surface of the SmFeN bonded magnet Characterized in that subjected to beveling the inner circumferential side circumferential end surface.

  Furthermore, the parts other than the head of the teeth of the stator core are insulated by injection molding with PBT, and the entire periphery of the core back of the stator core is also insulated by injection molding with PBT.

  Furthermore, in the armature winding of the permanent magnet rotating electric machine, the armature winding of each phase is formed by pairing the clockwise and counterclockwise directions or the counterclockwise and clockwise directions of winding around the stator core teeth. When winding clockwise or counterclockwise around a tooth, the beginning of winding is the inner peripheral side of the tooth and the end of winding is the outer peripheral side of the tooth, and when winding next to the adjacent tooth counterclockwise or clockwise, It is characterized in that the winding end is on the teeth inner peripheral side as the teeth outer peripheral side, and both the winding start and winding end of the armature winding are on the teeth inner peripheral side.

  According to the embodiment of the present invention, the multi-phase (U, V, W phase) armature winding is applied which is intensively wound so as to surround the teeth in a plurality of slots formed in the stator core. A rotor cup rotatably supported on the outer periphery of the stator via a predetermined gap, and a rotor having permanent magnets magnetized at substantially equal intervals on the inner peripheral surface of the rotor cup. A permanent magnet rotating electrical machine formed in a relationship of P: M = 6n ± 2: 6n (where n is an integer of 2 or more), where M is the number of teeth of the stator core and P is the number of permanent magnets. The SmFeN bonded magnet containing rare earth is partially disposed in the permanent magnet, the magnet length of the SmFeN bonded magnet is made longer than the thickness of the stator core, and the auxiliary groove is formed on the inner peripheral surface of the SmFeN bonded magnet. High output and low cogging torque by forming bevelling It can provide a permanent magnet rotating electrical machine capable of reducing vibration and noise by.

  Furthermore, the parts other than the teeth of the stator core teeth are injection molded with PBT to insulate, and the entire periphery of the core back of the stator core is also injection molded with PBT to insulate it from the armature winding. A permanent magnet rotating electrical machine capable of preventing leakage current and improving the reliability of the permanent magnet rotating electrical machine can be provided.

  Furthermore, in the armature winding of the permanent magnet rotating electric machine, the armature winding of each phase is formed by pairing the clockwise and counterclockwise directions or the counterclockwise and clockwise directions of winding around the stator core teeth. When winding clockwise or counterclockwise around a tooth, the beginning of winding is the inner peripheral side of the tooth and the end of winding is the outer peripheral side of the tooth, and when winding next to the adjacent tooth counterclockwise or clockwise, Permanent magnet so that the winding end is on the teeth inner peripheral side as the teeth outer peripheral side, the winding start and end of the armature winding are both on the teeth inner peripheral side, and there is no aerial wiring in the slot A permanent magnet rotating electrical machine capable of improving the reliability of the rotating electrical machine can be provided.

It is one Example which shows the axial sectional view of the permanent magnet rotary electric machine by this invention. It is AA sectional drawing of the permanent-magnet-type rotary electric machine of FIG. It is a figure which shows the dimensional terms of the permanent magnet of FIG. It is a figure which shows the relationship between the groove width of the auxiliary groove of the permanent magnet rotary electric machine of this invention, and cogging torque. It is a figure which shows the relationship between the height of the auxiliary groove of the permanent magnet rotary electric machine of this invention, and cogging torque. It is a figure which shows the relationship between the presence or absence of beveling of the permanent magnet rotary electric machine of this invention, and a cogging torque. The winding development view of an armature winding is shown.

  Description will be made with reference to FIGS.

  Hereinafter, description will be made based on the illustrated embodiment. As one embodiment, the description will be made assuming that it is used as a motor of a washing and drying machine. 1 and 2 show the permanent magnet rotating electric machine. The permanent magnet rotating electrical machine 1 includes a stator 2 and a rotor 3. The stator 2 comprises a stator core 4 comprising a tooth 5 and a core back 6 and a slot 7 formed between the teeth 5 and the inner peripheral surface of the slot 7 is covered with an insulating member 8 such as PBT formed by injection molding. ing. Further, an inner peripheral insulating portion 8A such as PBT formed by injection molding is provided on the inner peripheral surface of the core back 6, and the insulating member 8 also covers the end portion in the stacking direction of the stator core 4. That is, the stator core 4 other than the head of the teeth 5 is covered with the insulating member 8. In the slot 7, concentrated winding armature windings 9 (three-phase windings consisting of a U phase, a V phase and a W phase) are mounted. The inner peripheral side of the inner peripheral insulating portion 8A is supported by a fixing member 15, the shaft 16 and the fixing member 15 are supported by a bearing 18 and a bearing 19, 20 is a C ring, and 21 is a corrugated spring. Reference numeral 22 denotes a motor single plate, and 23 denotes a caulking that connects the laminated stator cores 4 together. The rotor cup 10 is supported by a knurl 17 provided at the end of the shaft 16, and an auxiliary groove 13 (13 A, 13 B) and a beveling 14 (14 A, 14 B) are provided on the inner peripheral surface of the rotor cup 10. 12 is fixed by adhesion or resin injection molding. On the inner periphery of the SmFeN bonded magnet 12, the stator 2 is arranged with a gap 11 between the SmFeN bonded magnet 12 and the stator core 4. In other words, the rotor cup 10 is rotatably supported on the outer periphery of the stator 2 via the predetermined gap 11.

  The permanent magnet rotating electrical machine 1 described above is a multi-phase (U, V, W phase) armature winding wound intensively so as to surround the teeth 5 in a plurality of slots 7 formed in the stator core 4. The stator 2 provided with the wire 9, the rotor cup rotatably supported on the outer periphery of the stator 2 via a predetermined gap 11, and the inner peripheral surface of the rotor cup 10 are magnetized at substantially equal intervals. And a rotor 3 with permanent magnets, where M is the number of teeth 5 of the stator core 4 and P is the number of permanent magnets 12, P: M = 6n ± 2: 6n (where n is 2 or more) In the permanent magnet rotating electric machine formed in the relation of the integer), the SmFeN bonded magnet 12 containing rare earth is partially disposed in the permanent magnet, and the SmFeN bonded magnet 12 Increase the magnet length and provide auxiliary grooves and beveling on the inner peripheral surface of the SmFeN bonded magnet. It is those that form.

  That is, when n = 2, in the case of 10 poles and 12 slots, the least common multiple of the number of poles and the number of slots is 5 × 6 = 30, the wave of cogging torque is 30th, and the cogging torque itself does not increase. However, in order to reduce the size, weight, and output, when the SmFeN bonded magnet 12 containing rare earths from ferrite bonded magnets is used as the permanent magnet 12, the cogging torque is increased despite the use of 10 poles and 12 slots. It became bigger. When this SmFeN bonded magnet 12 was used, the relationship between the dimensional terms of the magnet and the cogging torque was examined.

  FIG. 3 is a diagram showing dimensions around the magnet of the permanent magnet rotating electric machine of the present invention, FIG. 4 is a diagram showing the relationship between the groove width of the auxiliary groove and the cogging torque, and FIG. 5 is a diagram showing the height of the auxiliary groove and the cogging torque. FIG. 6 is a diagram showing the relationship, and FIG. 6 is a diagram showing the relationship between the presence of beveling and the cogging torque.

  As shown in FIG. 3, when the gap between the magnets is divided into three equal parts and an auxiliary groove (concave groove) is provided on the inner circumferential surface of the magnet divided into three parts, the width of the groove is shown in FIG. is there. When the groove height is constant at 0.47 mm and the relationship between the groove width (expressed in angle, but half the angle is almost the circumference (mm)) and cogging torque, the groove width If the angle is set to 5.5 degrees or less, the cogging torque becomes minimum. Then, no matter how much the groove width can be reduced, the effect is that the groove width is zero degree, since there is no auxiliary groove, so the cogging torque tends to increase at an angle of 2 degrees or less. The angle is in the range of 2 to 5.5 degrees.

  Next, FIG. 5 shows the height of the grooves when the gaps between the magnets are divided into three equal parts and auxiliary grooves (concave grooves) are provided on the inner circumferential surface of the divided magnets. When the groove width is kept constant at 2.5 degrees and the relationship between the groove height and the cogging torque is shown, the cogging torque becomes minimum when the groove width is set from 0.4 mm to 0.5 mm degrees or less.

  Further, FIG. 6 shows the presence or absence of beveling in the case where the space between the magnet poles is divided into three equal parts and auxiliary grooves (concave grooves) are provided on the inner circumferential surface of the magnet divided into three equal parts. The beveling is in the form of a paragraph provided to prevent a steep magnetic flux change at the end of the magnet, and when the stator thickness is 30 mm and the magnet length is 33.5 mm, the begging torque is 4.01 mNm. It becomes 15.7 mNm without beveling. When the stator thickness is 30 mm and the magnet length is 30 mm, the cogging torque is 3.41 mNm with beveling and 12.7 mNm without beveling.

  That is, what can be said from FIG. 6 suggests that beveling is effective in reducing the cogging torque, and that the cogging torque decreases as the magnet length is shortened with respect to the stator stack thickness. Since the present invention aims to achieve high output with a small size and light weight, it is necessary to increase the magnet length with respect to the stator stack thickness in order to achieve high output. The ring is effective.

4 and 5, when the minimum radial thickness of the magnetic pole piece of the stator core is H (see FIG. 2), the depth of the auxiliary groove is in the vicinity of 1H, and the width of the auxiliary groove is from 1H to 2. If it is within 75H, the cogging torque can be minimized.
The second object of the present invention is to improve the reliability of the permanent magnet rotating electric machine.

  From Fig. 1 and Fig. 2, the parts other than the teeth of the stator core teeth are insulated by injection molding with PBT, and the entire periphery of the core back of the stator core is also insulated by injection molding with PBT. When a current is supplied from an inverter (not shown) to the armature winding 9 to drive the magnet rotating electrical machine 1, the leakage current flowing due to the medieval point potential generated in the armature winding 9 is eliminated. The effect of eliminating the problem is obtained.

  FIG. 7 shows an exploded view of the armature winding. In FIG. 7, the same members as those in FIG. 1 and FIG. In FIG. 7, when the permanent magnet rotating electrical machine of the present invention has, for example, 10 poles and 12 slots, 12 teeth 5 are paired with 2 teeth, and armature windings 9 are applied. That is, the coil A of the armature winding 9 is wound around the tooth 5 in the counterclockwise direction from the lower tooth portion 5a of the winding start A1, and the winding is ended at the upper tooth portion 5b, and the adjacent upper tooth portion 5b starts to be wound. The last is the end A2 of the winding from the lower teeth 5a. Here, what is important is that the coil wound by the winding-down type winding machine is used, so that the coils wound around the adjacent teeth 5 are successively wound down from above, so the first coil wound from the adjacent is the teeth 5. By being held at the innermost circumference, no aerial wiring remains between the teeth 5. The coil B is wound clockwise around the teeth 5 from the winding start B1 and is wound around the adjacent teeth 5 counterclockwise, and the winding end is B2.

  That is, the coil of each phase is at the bottom of the tooth 5 at the beginning and end of winding, and there is no aerial wiring in the slot. A permanent magnet rotating electrical machine can be provided.

  The permanent magnet rotating electrical machine according to the present embodiment is a multi-phase (U, V, W phase) armature winding wound intensively so as to surround teeth in a plurality of slots formed in a stator core. , A rotor cup rotatably supported on the outer periphery of the stator via a predetermined gap, and a rotor having permanent magnets magnetized at substantially equal intervals on the rotating rotor cup. In the permanent magnet rotating electrical machine formed in the relationship of P: M = 6n ± 2: 6n (where n is an integer of 2 or more) where M is the number of teeth of the stator core and P is the number of the permanent magnets. The SmFeN bonded magnet containing rare earth in the permanent magnet is partially arranged, and the length of the SmFeN bonded magnet is made longer than the thickness of the stator core, and an auxiliary groove is formed on the inner peripheral surface of the SmFeN bonded magnet. High output and cogging torque can be achieved by forming bevelling. The reduced by reducing the vibration and noise, the leakage current and no aerial wiring having high reliability can be provided a permanent magnet rotating electric machine.

  In the above-described embodiment, the example in which the permanent magnet rotating electric machine 1 is used for a washing / drying machine has been described.

  DESCRIPTION OF SYMBOLS 1 ... Permanent magnet rotary electric machine, 2 ... Stator, 3 ... Rotor, 4 ... Stator iron core, 5 ... Teeth, 5A ... Teeth taper part, 6 ... Core back, 7 ... Slot, 8 ... Insulation material, 8A ... Inside Peripheral insulation, 9 ... Armature winding (U phase, V phase, W phase), 10 ... Rotor cup, 11 ... Gap, 12 ... Permanent magnet, 13 ... Auxiliary groove, 14 ... Beveling, 15 ... Fixing member, 16 ... shaft, 17 ... knurl, 18 ... bearing A, 19 ... bearing B, 20 ... C ring, 21 ... thrust spring, 22 ... motor single plate, 23 ... caulking

Claims (6)

A stator with multi-phase (U, V, W phase) armature windings wound intensively so as to surround the teeth in a plurality of slots formed in the stator core;
A rotor cup rotatably supported on the outer periphery of the stator via a predetermined gap;
A rotor having permanent magnets magnetized at substantially equal intervals on the inner circumferential surface of the rotor cup, and
In a permanent magnet rotating electrical machine formed with a relationship of P: M = 6n ± 2: 6n (where n is an integer of 2 or more) where M is the number of teeth of the stator core and P is the number of permanent magnets. The permanent magnet rotating electric machine is characterized in that the permanent magnet is composed of an SmFeN bonded magnet and an auxiliary groove is formed on the inner peripheral surface of the SmFeN bonded magnet. In the permanent magnet rotating electric machine according to claim 1,
A permanent magnet rotating electrical machine characterized in that the permanent magnet is partially arranged on the circumference with an SmFeN bonded magnet, and the magnet length of the SmFeN bonded magnet is longer than the thickness of the stator core. In the permanent magnet rotating electric machine according to claim 1 or 2,
The auxiliary grooves provided on the inner peripheral surface of the SmFeN bonded magnet are arranged at positions corresponding to three equal parts between the poles, the minimum radial thickness of the pole pieces of the stator core is H, and the inner periphery of the SmFeN bonded magnet When the peripheral length of the surface is approximately 0.5 mm / degree, the depth of the auxiliary groove is set in the vicinity of H, and the width of the auxiliary groove is set in the vicinity of 1H to 2.75H. . The permanent magnet rotating electric machine according to claim 1,
The permanent magnet is insulated by injection molding with PBT except for the head of the teeth of the stator core, and the entire periphery of the core back of the stator core is also insulated by injection molding with the PBT. Rotating electric machine.   5. The permanent magnet rotating electric machine according to claim 1, wherein beveling is applied to an inner peripheral surface of the SmFeN bonded magnet. 6. A stator with multi-phase (U, V, W phase) armature windings wound intensively so as to surround the teeth in a plurality of slots formed in the stator core;
A rotor cup rotatably supported on the outer periphery of the stator via a predetermined gap;
A rotor having permanent magnets magnetized at substantially equal intervals on the inner peripheral surface of the rotor cup, and when the number of teeth of the stator core is M and the number of permanent magnets is P, P : In a permanent magnet rotating electrical machine formed in a relationship of M = 6n ± 2: 6n (where n is an integer of 2 or more),
The armature winding of each phase is composed of a pair of clockwise and counterclockwise or counterclockwise and clockwise directions wound around the teeth of the stator core, and the clockwise or When winding in the counterclockwise direction, the beginning of winding is the inner peripheral side of the teeth, and the end of winding is the outer peripheral side of the teeth. When winding the adjacent teeth on the counterclockwise or clockwise direction, A permanent magnet rotating electric machine characterized in that the winding end is on the inner peripheral side of the teeth on the outer peripheral side, and the winding start and end of the armature winding are both on the inner peripheral side of the teeth.

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