JP5147343B2 - Permanent magnet type rotary motor for washing machine fan drive - Google Patents

Description

  The present invention relates to a technique of a permanent magnet type rotary electric motor and a washing machine using the same.

  Inverter-driven permanent magnet electric motors are used for rotary electric motors that drive the rotating blades and drums of washing machines. In washing machines, the level of noise affects the quality of products, so various slot combinations are used in permanent magnet motors that use concentrated winding stators. Currently, the 2-pole 3-slot series, the 10-pole 12-slot series, and the 4-pole 3-slot series are employed, but there are other 8-pole 9-slot series.

  As a characteristic of the combination of the number of slots and the number of magnetic poles of this type of permanent magnet motor, the 10-pole 12-slot series and the 8-pole 9-slot series are important if the cogging torque is important, and 2 if the reluctance torque and field weakening are important. 3-pole series, 2-pole 3-slot series and 10-pole 12-slot series if the end length of the coil is important, 4-pole 3-slot series if the winding cost is important, 2-pole 3-slot It is well known that the series is a 10 pole 12 slot series, and that the 8 pole 9 slot series is also a unique characteristic. Considering these characteristics, the number of slots and the magnetic pole A combination is used (see Non-Patent Document 1).

Further, as a noise countermeasure, a cogging torque is generally reduced by skewing a stator, a rotor, or the like (see Non-Patent Document 1).
In addition, the rotor is divided into a plurality of ranges, and the positions of the magnetic pole core convex portions of the divided ranges are shifted in a stepwise manner in the circumferential direction of the rotor, and the phase difference between the generated cogging torque and pulsation torque It is also a known technique to reduce noise by reducing the pulsation torque by setting the angle to 180 degrees (see Patent Document 1).
Hitachi, Ltd. General Education Center Technical Training Center "Small motor technology that is easy to understand" Published by Ohm Corporation p21-22 JP 2004-48912 A

  In the known technique, since the cogging torque itself is not reduced, the noise is not sufficiently reduced.

A permanent magnet for driving a washing machine fan comprising a stator having armature windings in a plurality of slots formed in the stator core, and a rotor having a plurality of permanent magnets as magnetic poles embedded in the core In the rotary motor, the rotor is divided into a plurality of ranges in the axial direction, and the magnetic core iron convex angle opening in each of the divided ranges is symmetric with respect to the magnetic pole center of the rotor. The second segment range is sandwiched between the ranges, and the magnetic pole core convex angle angle opening in the second segment range is larger than the magnetic core convex angle angle opening in the first and third segment ranges. By narrowing the degree, a V-shaped skew was formed in which both end sides of each magnetic pole core convex portion face each other.

The length of each segment range in the axial direction is adjusted so that the amplitude of the cogging torque generated in each segment range is the same, and the magnetic pole core convex portion angular opening is adjusted so that the phase difference of the cogging torque is 180. By setting the degree, the cogging torque itself can be reduced.
Therefore, the pulsation torque is also reduced and the noise can be reduced.

    FIG. 1 is a radial sectional view of each permanent range of a permanent magnet type rotary motor having a concentrated winding stator according to the present invention divided in the axial direction of the rotor, and FIG. 2 is a view of fixing the permanent magnet type rotary motor of FIG. FIG. 3 is an enlarged view of the rotor of the permanent magnet type rotary electric motor of FIG. 1, FIG. 3 (a) is an enlarged view of FIGS. 1 (a) and 1 (c), and FIG. FIG. 4B is an enlarged view of FIG. 1B, and FIG. 4 is a perspective view of the rotor of the permanent magnet type rotary electric motor of FIG.

Description will be made with reference to FIGS.
In each figure, the common code | symbol shows the same thing. Further, here, a 6-pole 9-slot permanent magnet type rotary electric motor which is a 2-pole 3-slot series is shown.

  A permanent magnet type rotary electric motor 1 having a concentrated winding stator is composed of a stator 2 and a rotor 3. The stator 2 includes a stator core 6 including a tooth 4 and a core back 5, and concentrated armature windings 8 (three-phase windings) wound around the teeth 4 in slots 7 between the teeth 4. Wire U phase winding 8a, V phase winding 8b, and W phase winding 8c). Here, since the permanent magnet type rotary electric motor 1 has 6 poles and 9 slots, the slot pitch is 120 degrees in electrical angle. Moreover, the inner peripheral surface of the teeth 4 facing the rotor 3 is a magnetic pole piece 11 having an arcuate portion 9 and a beveling 10 as shown in FIG.

The rotor 3 includes a shaft hole 15 in which a permanent magnet 14 is housed in a single-letter permanent magnet insertion hole 13 formed in the rotor core 12, and is fitted to a shaft (not shown). Here, the axis extending in the direction of the magnetic pole center of the rotor 3 is d-axis. The axis extending in the direction between the magnetic poles separated by 90 ° in electrical angle from the magnetic pole center direction is defined as the q axis. The magnetic flux of the permanent magnet 14 is gathered to the magnetic pole side by providing a concave portion 16 having a shape obtained by combining two substantially V-shapes cut in a straight line on the gap (q-axis) side of the outer peripheral surface of the rotor core 12. The rotor magnetic pole 17 that plays the role of forming is formed. The rotor 3 is divided into three parts in the axial direction, and the first divided range is a magnetic core iron convex angle opening θ1 (here, “magnetic core iron convex angle opening” shown in FIG. 3A). Is a rotor portion (hereinafter referred to as "rotor 1") in which a plurality of magnetic steel sheets of magnetic pole core convex portions 17 (a) or 17 (b) are angles desired from the rotor central axis) are laminated. The second range section is a rotor portion (hereinafter referred to as “rotor 2”) in which a plurality of magnetic steel sheets having a magnetic core convexity opening angle θ2 narrower than the magnetic core convexity opening angle θ1 shown in FIG. ), The third range section is composed of a rotor portion having the same configuration as the rotor 1 (hereinafter referred to as “rotor 1”).
As shown in FIG. 4, the rotor 3 is configured such that the rotor 2 is sandwiched between rotors 1 having the same structure, and each magnetic core protrusion 17 (a), 17 (b) is a magnetic pole. It is configured to be symmetric with respect to the center.

  5 shows that the magnetic core iron convex angle opening θ1 and θ2 are mechanical angles θ1 = 40 ° and θ2 = 30 ° in FIG. 4, and the axial length of the rotor 1 is the axial length of the rotor 2. It is the figure which showed the cogging torque waveform of the rotor 1 and the rotor 2 in an experiment example longer than this (length ratio: 20 to 15). In the drawing, the cogging torques of the rotor 1 and the rotor 2 are shifted by approximately 180 degrees in electrical angle, and a decrease in the combined cogging torque is shown.

FIG. 6 shows the torque generated in the permanent magnet type rotary electric motor under the conditions of FIGS.
When the axial length of the rotor 1 is made longer than the axial length of the rotor 2 to minimize the pulsating torque combined with the DC torque while intentionally leaving the cogging torque, that is, when combining with the DC torque In order to minimize the pulsation of the combined torque, the canceling amount of the cogging torque generated in the rotor 1 and the rotor 2 is adjusted by the ratio of the axial length so that the phase difference of the cogging torque becomes 180 degrees. In addition, the ratio of the magnetic pole core convex portion angular opening θ1 and θ2 is adjusted.
Then, from the figure, the cogging torque is about 0.006 peak-to-peak with respect to about 0.281 Nm of DC torque, and the ratio is very small, about 2%, and the pulsating torque during operation is peak-to-peak. Is about 0.017 Nm, which is very small, about 6% of the DC torque.

In addition, since harmonic components of a specific order cause noise problems (see paragraph “0004” in Patent Document 1), the harmonic components of a specific order are used as rotor core 1 and rotor core magnetic core convex portion angular opening θ1. , Θ2 may be adjusted and canceled.
For example, in the case of canceling the tertiary component in the 6-station 9-slot permanent magnet rotary motor shown in FIG.
Since there are six stations, the angle of one pole = 360/6 = 60 degrees. When 60 degrees is divided by 3, which is the harmonic order, 60/3 = 20 degrees.
In view of this, the magnetic pole core convex angle openings θ1 and θ2 of the rotors 1 and 2 are set to 20 degrees.

Next, the case where it applies to a washing machine is described.
FIG. 7 is a schematic view showing a washing / drying machine equipped with a permanent magnet type rotary electric motor having a concentrated winding stator according to the present invention in a longitudinal section.

In FIG. 7, reference numeral 20 denotes a rectangular cylindrical outer frame constituting the outer shell. The outer frame 20 is made of a chromium-free precoated steel plate.
Reference numeral 21 denotes a washing and dewatering tub, which has a small hole 21a for water flow and ventilation on its peripheral wall, a fluid balancer 22 on its upper edge, and a stirring blade 23 that is freely rotatable inside the bottom. Has been. Reference numeral 24 denotes an outer tub that encloses the washing / dehydrating tub 21 and stores washing water and rinsing water. A driving device 25 is attached to the outside of the bottom portion by a mounting base 26 made of a steel plate. The outer tub 24 is supported by four anti-vibration support devices 27 locked to the four corners at the upper end of the outer frame 20 so that the outer tub 24 is suspended from the center of the outer frame 20 by evenly suspending from four directions. ing.

  The stirring blade 23 has a large diameter (the outer diameter is 90% or more of the inner diameter of the washing / dehydrating tub) that covers most of the bottom of the washing / dehydrating tub 21. Although the details of the stirring blade 23 are not shown, the central portion and the peripheral portion are high, and the space between them is low, and the peripheral portion is curved upward so as to approach the outer periphery, and supports the laundry 28. Rotating.

  The drive unit 25 includes a brushless DC motor 29, an electric operation clutch mechanism 30, and a planetary gear speed reduction mechanism 31, and rotates the stirring blade 23 with the washing / dehydrating tub 21 stationary (stirring mode) to perform washing / removal. The water tank 21 and the stirring blade 23 are rotated in opposite directions (washing mode), respectively, and a selective drive function is provided to rotate the washing / dehydration tank 21 and the stirring blade 23 integrally (dehydration / drying mode).

  A drain outlet 24 b formed at the bottom of the outer tub 24 is connected to a drain hose 33 via a drain solenoid valve 32. The air trap 24 c is connected to the water level sensor 35 through the air tube 34. At the lower end edge of the outer frame 20, a base 37 made of synthetic resin with legs 36 attached to the four corners is attached.

  The top cover 39 having the outer garment insertion port 38 is fitted to the opening edge so as to cover the upper opening of the outer frame 20, is attached together with the front panel 40 and the back panel 41, and is attached to the outer frame 20 by screws.

  Although not shown in detail, the outer garment insertion port 38 formed in the top cover 39 is covered with an outer lid 43 attached to the top cover 39 by a hinge 42 so as to open in half (mountain fold). The inner garment insertion port 45 formed on the outer tub upper cover 44 attached to the upper end of 24 is configured to be opened and closed by an inner lid 47 attached to the outer tub upper cover 44 by a hinge 46.

  A front panel box 48, which is a front storage portion formed between the top cover 39 and the front panel 40, includes a power switch 49, an operation panel 50, an unbalance detection sensor 51, and a lid switch 52. The unbalance detection sensor 51 causes the washing / dehydration tub 21 (outer tub 24) to largely shake more than a predetermined value due to the unbalance of the laundry 28 in the washing / dehydration tub 21 when the washing / dehydration tub 21 is rotated. It is a sensor that detects The lid switch 52 detects opening / closing of the outer lid 43.

  The operation panel 50 is provided with setting buttons for determining a washing course, a drying course, a washing / drying course, and the like.

  The back panel box 53 formed between the top cover 39 and the back panel 41 incorporates washing water supply means and high-concentration detergent liquid generation / supply means, which will be described later, side by side, and at the water level in the outer tub 24. A water level sensor 35 that generates a corresponding water level signal and a controller 54 are incorporated.

  The washing water supply means is constituted by a main water supply electromagnetic valve 58 having a water inlet side connected to a faucet connection port 55 and a water outlet side connected to a water injection port 57 via a detergent dissolution container 56.

  The high-concentration detergent solution generation / supply means supplies detergent-dissolved water to the detergent-dissolving container 56 via the auxiliary water supply electromagnetic valve 59, and stirs the powder synthetic detergent charged in the detergent-dissolving container 56 Concentration detergent liquid is produced | generated, it overflows from the detergent melt | dissolution container 56, diluting with further water supply, and it comprises so that it may supply to the water inlet 57. The detergent dissolution container 56 is provided with a finishing agent charging chamber. By supplying water from the auxiliary water supply solenoid valve 60, the softening finishing agent charged in the detergent dissolution container 56 overflows from the finishing agent charging chamber. The water inlet 57 is configured to be supplied.

  The hot air circulation drying means is the washing that has entered from the suction port 61 formed to extend upward in the vertical state along the outer wall surface on the rear side of the outer tub 24 from the suction port 61 formed on the lower side wall of the outer tub 24. A water-cooled dehumidifying duct 62 that is a dehumidifying air passage section that dams water, a cooling water sprinkling section 63 that is a water-cooled dehumidifying means that is located in the upper part of the water-cooled dehumidifying duct 62 and supplies cooling water into the duct, and a washing process A descending air duct duct 64 that is a descending air duct portion that is folded back at a position higher than the water level of the outer tank 24 and extends vertically along the outer wall surface of the outer tank 24 toward the lower side of the outer tank 24, and the outer tank 24 The circulation fan 65 is disposed in the lower space and sucks air from the descending air duct 64 into the suction port to generate circulating air, and the upper side of the circulation fan 65 along the outer wall surface of the outer tub 24 from the outlet. Ascending air duct duct 66, which is an ascending air passage portion extending vertically to the direction Built-in heater (PTC heater) 67 which is installed on the outer tank upper cover 44 attached to the upper end of the outer tank 24 and heats the circulating air sent from the updraft duct 66 is heated and circulated. A blowing port 68 for blowing air into the washing / dehydrating tank 21 is provided.

  A yarn waste collecting means 69 is provided at the folded portion from the water-cooled dehumidifying duct 62 to the descending air duct 64. In addition, a humidity sensor 70 and a temperature sensor 71 are installed in the lower part of the descending air duct 64, and a second temperature sensor 72 is installed in the downstream air path of the heater 67 at the inlet 68. Water supply to the cooling water sprinkling unit 63 is performed from a cooling water spraying electromagnetic valve 73, and both are connected by a bellows hose 74.

  The water-cooled dehumidifying duct 62, the descending air duct 64, and the ascending air duct 66 constituting the circulation air path are arranged on the outer wall surface on the rear side of the outer tank 24 in the circumferential direction of the outer tank 24, and a part thereof is connected to the outer tank 24. The back cover 75 that is integrally molded and mounted and covers these outsides is configured to bulge outward and is screwed.

  This hot air circulation drying means drains the washing water in the outer tub 24 after washing, spins the washing and dewatering tub 21 at a high speed, spins it at a high speed, spins at a low speed, or stirring blades By operating the circulation fan 65 while reversing the direction 23 in the forward and reverse directions, the wet water in the outer tub 24 and the washing and dewatering tub 21 is sucked out from the suction port 61, and in the process of raising the water-cooled dehumidification duct 62, the cooling water sprinkling unit The water is cooled and dehumidified by cooling water supplied from 63 into the water-cooled dehumidifying duct 62. Thereafter, the dehumidified air is lowered into the descending air duct 64 and sucked into the circulation fan 65, sent from the circulation fan 65 through the ascending duct duct 66 and the heater 67 to the blowing port 68, and heated by the heater 67 to be washed and removed. Blow toward the center of the aquarium 21. Thus, the circulating air blown into the washing / dehydrating tank 21 touches the laundry 28 in the washing / dehydrating tank 21 to dry the laundry.

  The permanent magnet rotary electric motor 1 of the present invention was applied to the circulation fan 65 of the washing machine, and the noise of the washing machine 20 when measured at a rotational speed of 15000 r / min was measured from the front. As a result, the conventional permanent magnet type rotary electric motor with V-shaped skew was 55 dB, whereas the permanent magnet type rotary electric motor of the present invention was 49 dB. From this, it is clear that the permanent magnet type rotary electric motor of the present invention has an effect of reducing noise due to cogging torque and pulsation torque.

  In the above embodiment, an example of 6 poles and 9 slots of a 2 pole 3 slot series is shown, but it goes without saying that a permanent magnet type rotary electric motor using a distributed winding for a 4 pole 3 slot series or a stator may be used.

  According to the above configuration, the inner peripheral surface of the magnetic pole piece of the stator is beveled, and the rotor is constituted by the rotor 1 having a wide magnetic pole core convex portion angular opening and the rotor 2 having a small width. By making the axial lengths of the rotor 2 and the rotor 2 different, it is possible to reduce noise due to cogging torque and pulsation torque.

  As described above, according to the present invention, by providing a plurality of divided ranges in the axial direction of the magnetic pole core convex portion of the rotor, the cogging torques generated in the respective divided ranges are different from each other. Therefore, in any technical field that uses a DC brushless motor, such as a compressor, the compressor is not limited to a washing machine. Is also available.

Radial cross-sectional view for each divided range in which the permanent magnet type rotary electric motor having the concentrated winding stator according to the present invention is divided in the axial direction of the rotor. Enlarged view of the stator of the permanent magnet type rotary motor of FIG. Enlarged view of the rotor for each section range in FIG. 1 is a perspective view of a rotor of the permanent magnet type rotary electric motor of FIG. Cogging torque of the permanent magnet type rotary motor shown in FIG. Torque generated by the permanent magnet type rotating motor shown in FIG. Longitudinal cross-sectional schematic view of a washing and drying machine equipped with a permanent magnet type rotary electric motor having a concentrated winding stator of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Permanent magnet type rotary motor 2 ... Stator 3 ... Rotor 4 ... Teeth 5 ... Core back 6 ... Stator Iron core 7 ··· Slot 8 ··· Armature winding 9 ··· Arc portion 10 · · · Beveling 11 · · · Magnetic pole piece 12 · · · Rotor core 13 · · · ... permanent magnet insertion hole 14 ... permanent magnet 15 ... shaft hole 16 ... recess 17 ... rotor magnetic pole 17 (a). Magnetic pole core convex part 17 (b), magnetic pole core convex part 20 ... outer frame 21 ... washing and dewatering layer 22 ... fluid balancer 23 ... stirring blade 24 ... outer tank 25 ... Drive device 26 ... Mounting base 27 ... Vibration-proof support device 28 ... Laundry 29 ... Brushless DC motor 30 ... Electric operation clutch mechanism 31 ... ··· Planetary gear reduction mechanism 32 ··· Drain solenoid valve 33 ··· Drain hose 34 ··· Air tube 35 ··· Water level sensor 36 · · · Leg 37 ··· Base 38 ··· ··· Outer clothing input port 39 ··· Top cover 40 · · · Front panel 41 · · · Back panel 42 · · · Hinge 43 · · · Outer lid 44 · · · Outer tank upper cover 45 .... Inner clothing input port 46 ... Hinge 47 ... Inner lid 48 ... Front panel box 49 ... Power switch 50 ... Operation panel 51 ... Unbalance detection sensor 52 ... Cover switch 53 ... Back panel box 54 ... Controller 55 ... · · Water faucet connection port 56 · · · Detergent dissolution container 57 · · · Water injection port 58 · · · Main water supply solenoid valve 59 · · · Auxiliary water supply solenoid valve 60 · · · Auxiliary water supply solenoid valve 61 · ... Suction port 62 ... Water-cooled dehumidification duct 63 ... Cooling water sprinkling part 64 ... Down air duct duct 65 ... Circulating fan 66 ... Up air duct 67 ... ··· Heater 68 ··· Blowing port 69 ··· Waste lint repair means 70 ··· Humidity sensor 71 ··· Temperature sensor 72 ··· Second temperature sensor 73 ··· Cooling sprinkler Solenoid valve 74 ... Bellows hose 75 ... Back side .

Claims (3)

A permanent magnet for driving a washing machine fan comprising a stator having armature windings in a plurality of slots formed in the stator core, and a rotor having a plurality of permanent magnets as magnetic poles embedded in the core Type rotary motor,
The rotor is divided into a plurality of ranges in the axial direction, and the magnetic pole core convex portion angular opening in each of the divided ranges is symmetric with respect to the magnetic pole center of the rotor, and between the first and third divided ranges. The second segment range is sandwiched, and the magnetic pole core convex angle angle opening in the second segment range is narrower than the magnetic core convex angle angle opening in the second and third segment ranges. By doing so, the permanent magnet type rotary motor for driving a washing machine fan in which both end sides of each magnetic pole core convex part form a V-shaped skew facing each other . 2. The permanent magnet rotary motor for driving a washing machine fan according to claim 1, wherein the axial length of each divided range is set so that the amplitude of the cogging torque generated for each divided range becomes a desired size. . The stator iron core according to claim 1 or 2, wherein the stator iron core is a permanent magnet rotary electric motor for driving a washing machine fan having an inner peripheral surface beveled.

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