JP2009189155A - Rotor of synchronous electric motor, blower electric motor, air conditioner, pump and water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor of a synchronous electric motor for improving output and efficiency without increasing vibration and noise of the synchronous electric motor. <P>SOLUTION: In the rotor 100 of the synchronous electric motor, a ring-like magnet 1 is arranged on a surface of a back yoke 2 of a magnetic body. An outer peripheral face of the magnet 1 has an almost perfect circle, a pole center 3 being a center part of a magnet pole is thick, and an interpole part 4 whose magnetic pole switches is thin. The pole center 3 includes a uniform thickness part 5 whose thickness in a radial direction becomes uniform for a prescribed length in a circumferential direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotor of a synchronous motor that realizes low cost, high efficiency, low noise, and high reliability. Furthermore, the present invention relates to a blower motor, an air conditioner, a pump, and a water heater using the rotor of the synchronous motor.

In order to suppress the pulsation of the torque that is generated by making the induced voltage generated in the motor sinusoidal, the stator yoke is provided with a multi-phase winding, and can be rotated concentrically inside the stator yoke. The rotor yoke is attached to the rotating shaft, and the rotor yoke is formed by attaching a ring-shaped permanent magnet made of magnetic plastic to the outer peripheral surface of the rotor yoke by molding. The yoke is configured so that the outer peripheral surface of the peripheral wall is a sinusoidal curved surface relative to the virtual perfect circle surface, and the permanent magnet has a perfect circular shape on the outer peripheral surface and a constant gap with the stator yoke. In addition, the portion where the thickness of the permanent magnet is maximum in the radial direction is alternately magnetized in the circumferential direction so as to be the center of the magnetic poles of the N pole and the S pole. It is configured to become thinner as it goes to the extreme. The outer peripheral surface of the surface and the rotor yoke has been proposed a permanent magnet motor in contact over the entire periphery (e.g., see Patent Document 1).
Japanese Patent No. 3865332

  As described in Patent Document 1, in order to make the distribution of magnetic flux density on the rotor surface sinusoidal, for example, the shape of the magnet arranged on the rotor surface is made thicker at the center part of the magnetic pole. In some cases, the thickness gradually decreases between the magnetic poles. In this case, the maximum value of the magnetic flux density in the gap between the rotor and the stator when the rotor and the stator are combined, in other words, the amplitude of the magnetic flux density distributed in a sinusoidal shape depends on the thickness of the magnet. Determined. For this reason, in order to increase the magnetic flux density, it is necessary to increase the thickness of the magnet, and there is a problem that the amount of magnet used increases.

  In order to make it more sinusoidal, the thickness of the magnet between the magnetic poles must be reduced, and the strength of the ring magnet is greatly reduced at that portion. In general, such magnets often have a magnetic back yoke, and if the expansion coefficient of the back yoke differs greatly from the magnet due to temperature changes in the usage environment, stress is applied to the magnet. And cracks may occur from the aforementioned thin portion.

  Alternatively, in order to obtain a larger amount of magnetic flux generated from the rotor, it is possible to realize the distribution of the magnetic flux density on the surface close to a rectangle (trapezoidal shape). However, in this case, the harmonic component contained in the induced voltage increases, and the torque pulsation becomes large, causing vibration and noise.

  SUMMARY OF THE INVENTION The present invention is made to solve the above-described problems. The synchronous motor rotor and blower motor can improve the output and efficiency without increasing the vibration and noise of the synchronous motor. An object is to provide an air conditioner, a pump, and a water heater.

The rotor of the synchronous motor according to the present invention is the rotor of the synchronous motor in which a ring-shaped magnet is disposed on the surface of the magnetic back yoke.
The magnet has a substantially circular outer peripheral surface,
The pole center, which is the center part of the magnetic pole, is thick, and the part between the poles where the magnetic pole changes is thin,
The pole center is provided with a uniform thickness portion having a predetermined length in the circumferential direction and a uniform thickness in the radial direction.

  In the rotor of the synchronous motor according to the present invention, the center of the pole where the magnet is the central part of the magnetic pole is thick, the part between the poles where the magnetic pole is switched is thin, and the pole center has a predetermined length in the circumferential direction and a radial direction By providing a uniform thickness part with uniform thickness, the distribution of magnetic flux density generated on the surface is nxm order with one magnetic pole pair as the fundamental frequency (where n is the number of stator winding phases and m is an odd number) Even if the maximum value of the magnetic flux density is the same, it is possible to include a large amount of the primary frequency component necessary for generating torque, and it is possible to increase the torque and efficiency of the synchronous motor. Become. In addition, n × m-order harmonic components cancel each other out in the n-phase stator windings and do not appear in the induced voltage, so no extra torque pulsation occurs and vibration and noise increase. I won't let you. In addition, by providing a uniform thickness between the magnetic poles, it is possible to disperse the stress generated in the magnet due to the temperature change in the use environment, thereby suppressing the occurrence of cracks.

Embodiment 1 FIG.
1 to 4 show the first embodiment. FIG. 1 (a) is a plan view showing a part of a rotor 100 of a synchronous motor, FIG. 1 (b) is a main part development view, and FIG. ) Is a perspective view of the back yoke 2, FIG. 1 (d) is a perspective view of the rotor 100 of the synchronous motor, FIG. 2 is a diagram showing a surface magnetic flux density distribution of the rotor 100 of the synchronous motor, and FIG. 3 is a rotation of the synchronous motor. FIG. 4 is a diagram showing the relationship between the content ratio of the third-order frequency component contained in the surface magnetic flux density waveform of the child 100 and the ratio of the fundamental frequency component, and FIG. It is a figure which shows the relationship between the angle of the flat part in the waveform of the wave of a tertiary frequency component and one magnetic pole.

  As shown in FIG. 1, the rotor 100 of the synchronous motor according to the present embodiment has a ring-shaped magnet 1 disposed on the surface of a magnetic back yoke 2. For the back yoke 2, for example, a mixed material of iron powder and resin is used. Since the linear expansion coefficients of the back yoke 2 and the magnet 1 are close to each other, the magnet 1 is difficult to break. The same applies to the following embodiments. As for the shape of the ring-shaped magnet 1, the outer peripheral surface is a substantially perfect circle, but the inner peripheral surface is not a perfect circle. The magnet 1 is thick at the pole center 3 which is the central part of the magnetic pole, and is thin at the inter-polar part 4 where the magnetic pole is switched.

  In addition, at the pole center 3 which is the center part of the magnetic pole, the outer arc and the inner arc of the magnet 1 are concentric circles. That is, the pole center 3 of the magnet 1 is a uniform thickness portion 5 having a predetermined length in the circumferential direction and a uniform thickness in the radial direction.

  As a result, compared with the ring-shaped magnet 1 having the same wall thickness as a whole, the magnetic flux generated from the magnet 1 can be increased by the thickness of the pole center 3 portion, and the magnetic flux generated on the surface of the magnet 1 can be increased. The density distribution has a substantially constant value near the pole center 3.

  In contrast to a sinusoidal distribution, a waveform whose peak is nearly flat includes odd-order harmonic components, and the amplitude of the fundamental component (primary component) included in the waveform is the observed waveform. It becomes larger than the amplitude of the waveform (the waveform near the peak of the waveform is almost flat).

  For example, FIG. 2 shows a waveform including a third-order harmonic component and a primary component of the waveform. As shown in FIG. 2, the amplitude of the primary component of the waveform including the harmonic component is larger than the amplitude of the waveform including the harmonic component.

  The torque generated by the synchronous motor using the magnet 1 depends on the magnitude of the primary component of the magnetic flux obtained from the rotor 100 of the synchronous motor. Therefore, the torque obtained by the synchronous motor using the synchronous motor rotor 100 of the present embodiment is greater than or equal to the maximum value (amplitude) of the magnetic flux obtained from the synchronous motor rotor 100.

  If a harmonic component is included in the distribution of the surface magnetic flux density of the magnet 1, pulsation is generated in the torque generated by the synchronous motor, causing vibration and noise. However, if the harmonic component to be superimposed on the waveform of the surface magnetic flux density distribution is only the nxm-order component (n is the number of phases of the stator winding and m is an odd number), this harmonic component is Since the phases are canceled out, there is no pulsation in the torque of the synchronous motor.

  Even in the magnet 1 that changes the thickness to a sinusoidal shape, it is possible to superimpose harmonic components on the magnetic flux density distribution on the surface as described above, depending on the magnetization of the magnet 1 or the magnetic field orientation during manufacture. It is easier to superimpose harmonics on the surface magnetic flux density distribution when the magnet 1 is shaped like the present embodiment.

  In FIG. 3, the horizontal axis shows the ratio of the frequency component of the surface magnetic flux density distribution for one magnetic pole pair, and the vertical axis shows the ratio of the amplitude of the primary component to the maximum amplitude at that time. The graph is shown.

  By including a third order component in the surface magnetic flux density distribution, a larger first order component can be obtained. The amplitude of the primary component can be increased by 10% or more with respect to the amplitude value of the waveform when the tertiary component is contained in the range of 9 to 28%, and particularly in the range of 14 to 20%. Maximum.

  At this time, the distribution of the surface magnetic flux density has a waveform having a flat portion at the pole center 3. The relationship between the content rate of the above-mentioned tertiary component and the width of the flat portion is as shown in FIG. This shows a range (flat portion width) in which the amplitude is 95% or more when the angle of one magnetic pole is 180 °.

  From this, the flat part width | variety of a magnetic flux density distribution waveform when a primary component becomes 10% or more becomes 60 degrees-106 degrees. Further, the flat portion width when the primary component becomes the largest is in the range of 84 ° to 97 °. By matching the range of the uniform thickness portion 5 of the pole center 3 of the magnet 1 with this, a surface magnetic flux density distribution waveform containing a lot of third harmonics can be realized.

  Such a magnet 1 can be configured by adhering a magnet manufactured separately from the back yoke 2, but when a plastic magnet is used for the magnet 1, the back yoke 2 as shown in FIG. It is also possible to constitute a rotor 100 of a synchronous motor in which a back yoke 2 and a magnet 1 are integrally formed as shown in FIG. .

  In this case, the uniform thick portion 5 can be easily formed by providing the small diameter portion 6 facing the uniform thick portion 5 of the magnet 1 on the outer periphery of the back yoke 2.

  In the rotor 100 of the synchronous motor having such a configuration, since the magnet 1 is formed of a thin ring shape, if a rare earth magnet is used for the magnet 1, the amount of use of the magnet 1 can be reduced and the cost is increased. Can be suppressed.

  As described above, according to the present embodiment, the shape of the ring-shaped magnet 1 is such that the outer peripheral surface is a substantially perfect circle, the pole center 3 is thick, and the inter-electrode portion 4 is thin. Furthermore, the pole center 3 of the magnet 1 is a uniform thickness portion 5 having a predetermined length and a uniform thickness in the circumferential direction. As a result, it is possible to include a large amount of primary frequency components necessary for generating torque, and it is possible to increase the torque and increase the efficiency of the synchronous motor.

  Further, the n × m-order harmonic components cancel each other in the n-phase stator winding and do not appear in the induced voltage, so that no excessive torque pulsation occurs and vibration and noise do not increase. .

  In addition, by providing the uniform thick portion 5, it is possible to disperse the stress generated in the magnet 1 due to the temperature change of the use environment and suppress the occurrence of cracks.

Embodiment 2. FIG.
5 and 6 are diagrams showing the second embodiment. FIG. 5 (a) is a plan view showing a part of the rotor 100 of the synchronous motor, FIG. 5 (b) is a main part development view, and FIG. ) Is a perspective view of the back yoke 2, FIG. 5D is a perspective view of the rotor 100 of the synchronous motor, and FIG. 6 is a diagram showing a surface magnetic flux density distribution of the rotor 100 of the synchronous motor.

  As shown in FIG. 5, neither the outer peripheral surface nor the inner peripheral surface of the ring-shaped magnet 1 is a perfect circle. The magnet 1 is thin at the interpolar part 4 where the pole center 3 which is the center part of the magnetic pole is thick and the magnetic pole is switched.

  Further, the inter-electrode portion 4 has a small-diameter portion 7 whose outer diameter is smaller than the outer diameter of the pole center 3. The thickness of the thin portion of the inter-electrode portion 4 is the same as that of the first embodiment, and even if the outer periphery is smaller than the outer diameter of the pole center 3, it is not always necessary to reduce the thickness.

  Compared to the ring-shaped magnet 1 having the same wall thickness as a whole, the magnetic flux generated from the magnet 1 can be increased as much as the thickness of the pole center 3 can be increased, as in the first embodiment. Furthermore, since the distance between the magnet 1 and the stator (not shown) is increased by providing the small-diameter portion 7 having a small outer periphery in the inter-electrode portion 4, the change in the magnetic flux density near the inter-electrode portion 4 where the magnetic pole is switched. Be gentle.

  FIG. 6 simulates the surface magnetic flux density distribution for one magnetic pole of the magnet 1. It can be seen that when the harmonic component is superimposed, the change in the magnetic flux density in the vicinity of the inter-pole portion 4 where the magnetic pole is switched becomes steep. Further, in the case of FIG. 6, the change in magnetic flux density in the vicinity of the pole-switching inter-electrode portion 4 is steep in the waveform in which the fifth-order component is further superimposed on the waveform in which the third-order component is superimposed.

  For this reason, by providing the small diameter portion 7 having a small diameter in the interpolar portion 4 as in the present embodiment, the change in magnetic flux density in the vicinity of the interpolar portion 4 where the magnetic pole is switched is moderated, thereby surface magnetic flux density distribution. Among higher harmonic components, higher-order components can be reduced, and generation of torque pulsation of the synchronous motor can be suppressed.

  Further, since the thin portion of the magnet 1 is likely to cause irreversible demagnetization due to a reverse magnetic field from the outside, the thin portion (thin portion of the interpolar portion 4) is kept away from the stator that generates the reverse magnetic field. Thus, it is possible to obtain the rotor 100 of the synchronous motor that is difficult to demagnetize.

  Moreover, even if it says the thin part of the magnet 1, in order to ensure intensity | strength, a certain amount of thickness is required. Therefore, there is a limit to making the inter-electrode portion 4 thin in order to moderate the change in the magnetic flux density of the inter-electrode portion 4. In the present embodiment, even if the thin portion of the inter-electrode portion 4 has a certain thickness, the outer diameter is reduced (the small-diameter portion 7 is provided), and the distance from the stator is made larger than the pole center 3. Thus, the change in magnetic flux density can be moderated, so that the strength of the magnet 1 can be ensured.

  The small-diameter portion 7 in which the outer peripheral diameter of the inter-electrode portion 4 becomes small can be formed by an arc, but by making it a planar shape cut on a straight line, the dimensions can be easily confirmed, and management at the time of manufacture can be performed. It becomes easy.

  Such a magnet 1 (FIG. 5) can be configured by bonding a separately manufactured back yoke 2 and the magnet as in the first embodiment. A synchronous motor in which the back yoke 2 and the magnet 1 are integrally formed as shown in FIG. 5 (d) by injection molding the magnet 1 in a mold in which the back yoke 2 is inserted as shown in FIG. 5 (c). It is also possible to constitute the rotor 100 of the above. In this case, a portion having a small diameter corresponding to the small diameter portion 7 is provided on the inner peripheral portion of the mold that forms the outer periphery of the magnet 1.

  As described above, according to the present embodiment, the magnet 1 is made thicker at the pole center 3 and thinner at the interpole part 4, and the outer periphery of the magnet 1 is further smaller than the diameter of the pole center 3 at the interpole part 4. By providing the small-diameter portion 7 that is smaller in size, the change in magnetic flux density in the vicinity of the inter-pole portion 4 where the magnetic poles are switched is moderated, thereby reducing higher-order components among the harmonic components of the surface magnetic flux density distribution. And the occurrence of torque pulsation of the synchronous motor can be suppressed.

Embodiment 3 FIG.
FIG. 7 is a diagram showing the third embodiment, FIG. 7 (a) is a plan view showing a part of the rotor 100 of the synchronous motor, FIG. 7 (b) is an exploded view of the main part, and FIG. The perspective view of the yoke 2 and FIG.7 (d) are perspective views of the rotor 100 of a synchronous motor.

  As shown in FIG. 7, the point that the ring-shaped magnet 1 is arranged on the surface of the magnetic back yoke 2 is the same as in the first and second embodiments.

  The shape of the magnet 1 is such that the pole center 3 which is the center part of the magnetic pole is thick, and the thickness is thin at the interpolar part 4 where the magnetic pole is switched. Further, the interpolar part 4 has a small diameter part 7 so that the outer periphery of the magnet 1 is smaller than the diameter of the pole center 3. Here, the small diameter portion 7 is a plane cut on a straight line. Furthermore, an inner peripheral plane portion 8 parallel to the outer peripheral small diameter portion 7 exists also on the inner periphery of the interpolar portion 4 of the magnet 1.

  Thereby, the inter-electrode portion 4 has a uniform thickness in the vicinity where the inner peripheral plane portion 8 exists.

  When stress is applied to the thin ring-shaped magnet 1, such as when the expansion coefficient differs greatly due to the difference in material between the back yoke 2 and the magnet 1, stress concentrates on the thinnest part of the magnet 1 and cracks occur. May occur.

  When the magnet 1 having the shape shown in the present embodiment is used, the thin portion (interpolar portion 4) of the magnet 1 has a uniform thickness at the inner peripheral plane portion 8. Therefore, the stress concentrates at both ends of the inner peripheral plane portion 8 where the thickness changes. As a result, the portion where the stress is concentrated is dispersed, the magnitude of the stress itself is reduced, and the magnet 1 is not easily cracked.

  When the magnet 1 is integrally formed by insert molding of the back yoke 2, the gate portion for injecting the magnet material into the space inside the mold that forms the shape of the magnet 1 is installed in the thick portion of the magnet 1. For this reason, the material injected from the gate is in contact with the adjacent gate, that is, at the thin portion of the magnet 1, and the weld portion (the weld portion is an assembly of two or more flow fronts (flow tip portions)). To solidify.

  The weld portion has a lower strength than the other portions, and the conventional shape has a lower strength because it matches the thin portion. By shifting the part where the stress is concentrated from this part, the magnet becomes more difficult to break. In the present embodiment, the stress concentrates at both ends of the inner peripheral plane portion 8 where the wall thickness is shifted from the pole center 3, so that the stress is shifted from the weld portion.

  Further, the thickness in the vicinity of the inner peripheral plane portion 8 is constant, and the volume becomes smaller if the minimum thickness is the same as compared with the case where the inner periphery is an arc. For this reason, if the magnet 1 has the same volume, the volume of the pole center 4 part can be increased, so that the magnetic force of the rotor 100 of the synchronous motor can be improved.

  Such a magnet 1 (FIG. 7) can be configured by bonding a separately manufactured back yoke 2 and the magnet 1 as in the first and second embodiments. In FIG. 7 (c), the back yoke 2 and the magnet 1 are integrally formed as shown in FIG. 7 (d) by injection molding the magnet 1 into a mold having the back yoke 2 inserted therein. It is also possible to constitute the rotor 100 of the synchronous motor.

  As described above, according to the present embodiment, the shape of the magnet 1 is thin at the pole center 3 and thin at the inter-pole part 4, and the outer circumference of the magnet 1 is the diameter of the pole center 3 at the inter-pole part 4. A small-diameter portion 7 which is a plane cut on a straight line so as to be smaller than the inner diameter is provided, and an inner peripheral plane portion 8 parallel to the outer peripheral small-diameter portion 7 is also formed on the inner periphery of the interelectrode portion 4. Therefore, the thin part (interpolar part 4) of the magnet 1 has a uniform thickness at the inner peripheral plane part 8. Therefore, the stress concentrates at both ends of the inner peripheral plane portion 8 where the thickness changes, the portions where the stress concentrates are dispersed, the size of the stress itself is reduced, and the magnet 1 is not easily cracked. .

Embodiment 4 FIG.
FIG. 8 is a diagram showing the fourth embodiment, FIG. 8 (a) is a plan view showing a part of the rotor 100 of the synchronous motor, FIG. 8 (b) is a main part development view, and FIG. 8 (c) is a back view. The perspective view of the yoke 2 and FIG.8 (d) are perspective views of the rotor 100 of a synchronous motor.

  As shown in FIG. 8, the point that the ring-shaped magnet 1 is arranged on the surface of the magnetic back yoke 2 is the same as in the first to third embodiments.

  The shape of the magnet 1 is such that the pole center 3 which is the center part of the magnetic pole is thick, and the thickness is thin at the interpolar part 4 where the magnetic pole is switched. Further, the interpolar part 4 has a small-diameter part 7 which is a flat part such that the outer periphery of the magnet 1 is smaller than the diameter of the pole center 3. Furthermore, an inner peripheral plane portion 8 parallel to the outer peripheral small diameter portion 7 exists also on the inner periphery of the interpolar portion 4 of the magnet 1.

  Thereby, the inter-electrode portion 4 has a uniform thickness in the vicinity where the inner peripheral plane portion 8 exists.

  In addition, a uniform thick portion 5 exists at 3 parts of the pole center. This is a combination of the features of the first embodiment.

  As described above, according to the present embodiment, the shape of the magnet 1 is thin at the pole center 3 and thin at the inter-pole part 4, and the outer circumference of the magnet 1 is the diameter of the pole center 3 at the inter-pole part 4. A small-diameter portion 7 which is a plane cut on a straight line so as to be smaller than the inner diameter is provided, and an inner peripheral plane portion 8 parallel to the outer peripheral small-diameter portion 7 is also formed on the inner periphery of the interelectrode portion 4. Therefore, the thin part (interpolar part 4) of the magnet 1 has a uniform thickness at the inner peripheral plane part 8. Therefore, the stress concentrates at both ends of the inner peripheral plane portion 8 where the thickness changes, the stress concentrated portions are dispersed, the size of the stress itself is reduced, and the magnet 1 is not easily cracked.

  Furthermore, the pole center 3 of the magnet 1 is a uniform thickness portion 5 having a predetermined length and a uniform thickness in the circumferential direction. As a result, it is possible to include a large amount of primary frequency components necessary for generating torque, and it is possible to increase the torque and increase the efficiency of the synchronous motor.

Embodiment 5 FIG.
FIG. 9 is a diagram showing the fifth embodiment. FIG. 9 (a) is a plan view showing a part of the rotor 100 of the synchronous motor, FIG. 9 (b) is a development view of main parts, and FIG. A perspective view of the yoke 2 and FIG. 9D are perspective views of the rotor 100 of the synchronous motor.

  As shown in FIG. 9, the point that the ring-shaped magnet 1 is arranged on the surface of the magnetic back yoke 2 is the same as in the first to fourth embodiments.

  The shape of the magnet 1 is such that the pole center 3 which is the center part of the magnetic pole is thick, and the thickness is thin at the interpolar part 4 where the magnetic pole is switched. The outer periphery of the synchronous motor rotor 100 is a perfect circle. The inner periphery of the pole center 3 and the inter-pole portion 4 is a concentric circle on the outer periphery, and the arc of the pole center 3 is formed by an arc having a smaller diameter than the arc of the inter-pole portion 4. Thereby, the pole center 3 is provided with a uniform thickness portion 5 having a predetermined length and a uniform thickness in the circumferential direction. In addition, a uniform thickness portion 9 having a predetermined length and a uniform thickness in the circumferential direction is provided in the inter-electrode portion 4.

  By providing the uniform thick portion 5 at the pole center 3, an n × m-order harmonic component can be effectively superimposed on the waveform of the surface magnetic flux density distribution, so that torque improvement can be achieved while suppressing torque pulsation occurring in the synchronous motor. it can. Further, by providing the uniform thickness portion 9 in the inter-electrode portion 4, the stress applied to the magnet 1 can be dispersed on both sides of the uniform thickness portion 9, and the crack of the magnet 1 can be suppressed.

Embodiment 6 FIG.
FIG. 10 is a diagram illustrating the sixth embodiment, and is a diagram illustrating a configuration of the air conditioner 200.

  The air conditioner 200 is mounted with a synchronous motor using the rotor 100 of the synchronous motor according to any one of the first to fifth embodiments as a motor for a blower.

  The air conditioner 200 includes an indoor unit 10 and an outdoor unit 11.

  The indoor unit 10 is equipped with an indoor blower that blows air to an indoor heat exchanger (not shown). The indoor fan includes an indoor fan motor 12 (an example of a fan motor). The synchronous motor rotor 100 according to any one of the first to fifth embodiments is used for the indoor fan motor 12.

  The outdoor unit 11 is equipped with an outdoor fan that blows air to an outdoor heat exchanger (not shown). The outdoor blower includes an outdoor fan motor 13 (an example of a fan motor). The synchronous motor rotor 100 according to any one of the first to fifth embodiments is used for the outdoor fan motor 13.

  In particular, since the indoor fan motor 12 and the outdoor fan motor 13 are required to reduce noise, the synchronous motor using the rotor 100 of the synchronous motor according to any one of the first to fifth embodiments is used for these. Thus, power consumption can be reduced while suppressing vibration and noise generated from the air conditioner 200.

Embodiment 7 FIG.
FIG. 11 is a diagram showing the seventh embodiment, and is a longitudinal sectional view showing the configuration of the pump 300.

  A pump 300 shown in FIG. 11 uses the rotor 100 of the synchronous motor according to any one of the first to fifth embodiments as the rotor 16.

  The pump 300 causes the liquid (for example, water) sucked from the suction port 14 to be discharged from the discharge port 15 as the electric motor rotates the blade 17. Since the rotor 16 is integral with the blade 17, it is used in a liquid atmosphere. Between the stator 18 and the rotor 16, there is a seal portion 19 for waterproofing. Since a liquid exists between the seal portion 19 and the rotor 16, it is necessary to increase the distance to some extent so as not to cause a large resistance to operation.

  For this reason, the space | gap between the stator 18 and the rotor 16 is wide compared with a normal electric motor, and the magnetic flux of the rotor 16 becomes difficult to interlink with the winding of the stator 18. For this reason, in order to improve the efficiency of such a pump 300 as well, a small but high magnetic force rotor 16 is required.

  Speaking of high magnetic force materials, Ne—Fe—B rare earth magnets are usually used. However, in applications where the liquid is water, the aforementioned magnets are susceptible to oxidation and are not suitable for this application.

  On the other hand, by using a magnet of Sm—Fe—N, deterioration of the material can be suppressed, and a high magnetic force rotor 16 can be obtained, thereby improving the pump performance. Further, when the rotor 100 of the synchronous motor according to the first or fifth embodiment described above is used, the outer periphery of the rotor 16 is a perfect circle, so that the resistance of the liquid is small and the loss is small.

Embodiment 8 FIG.
FIG. 12 is a diagram illustrating the eighth embodiment, and is a diagram illustrating a configuration of the water heater 400.

  The water heater 400 uses the pump 300 of the seventh embodiment as the circulation pump 20. The pump 300 is used in the circulation pump 20 that circulates water through the heating unit 22 in order to heat the hot water in the tank 23 of the hot water supply unit 21. The pump 300 is used in the circulation pump 20 for heating and circulating hot water in a bath tub.

  In hot water supply machine 400, circulation pump 20 consumes electric power next to heating unit 22 and plays a role of circulating hot water. Therefore, by using pump 300 of Embodiment 7, the performance of hot water supply machine 400 is further improved. be able to.

  As an application example of the present invention, the rotor 100 of a synchronous motor can be applied to a synchronous motor used in the air conditioner 200, the pump 300, the hot water heater 400, and the like.

FIG. 1A is a plan view showing a part of a rotor 100 of a synchronous motor, FIG. 1B is a main part development view, and FIG. 1C is a view of a back yoke 2. FIG. FIG. 1D is a perspective view of a rotor 100 of a synchronous motor. FIG. 5 shows the first embodiment, and shows the surface magnetic flux density distribution of the rotor 100 of the synchronous motor. FIG. 5 shows the first embodiment and shows the relationship between the content ratio of the third-order frequency component and the ratio of the fundamental frequency component included in the waveform of the surface magnetic flux density of the rotor 100 of the synchronous motor. FIG. 5 shows the first embodiment, and shows the relationship between the third-order frequency component included in the surface magnetic flux density waveform of the rotor 100 of the synchronous motor and the angle of the flat portion in the waveform of one magnetic pole wave. FIG. 5A is a plan view showing a part of a rotor 100 of a synchronous motor, FIG. 5B is a main part development view, and FIG. FIG. 5D is a perspective view of the rotor 100 of the synchronous motor. FIG. 5 shows the second embodiment, and shows the surface magnetic flux density distribution of the rotor 100 of the synchronous motor. FIGS. 7A and 7B are diagrams showing the third embodiment, in which FIG. 7A is a plan view showing a part of the rotor 100 of the synchronous motor, FIG. 7B is an exploded view of main parts, and FIG. FIG. 7D is a perspective view of the rotor 100 of the synchronous motor. FIG. 8A is a plan view showing a part of a rotor 100 of a synchronous motor, FIG. 8B is a development view of main parts, and FIG. FIG. 8D is a perspective view of the rotor 100 of the synchronous motor. FIG. 9A is a plan view showing a part of the rotor 100 of the synchronous motor, FIG. 9B is a main part development view, and FIG. 9C is a view of the back yoke 2. FIG. FIG. 9D is a perspective view of the rotor 100 of the synchronous motor. FIG. 12 shows the sixth embodiment and shows the structure of the air conditioner 200. FIG. FIG. 10 is a longitudinal sectional view showing a configuration of a pump 300, showing Embodiment 7. FIG. 18 shows a configuration of a hot water heater 400 according to Embodiment 8.

Explanation of symbols

  1 magnet, 2 back yoke, 3 pole center, 4 pole part, 5 uniform thickness part, 6 small diameter part, 7 small diameter part, 8 inner peripheral plane part, 9 uniform thickness part, 10 indoor unit, 11 outdoor unit, 12 motors for indoor fans, 13 motors for outdoor fans, 14 suction ports, 15 discharge ports, 16 rotors, 17 blades, 18 stators, 19 seals, 20 circulation pumps, 21 hot water supply units, 22 heating units, 23 tanks, 100 rotor of synchronous motor, 200 air conditioner, 300 pump, 400 water heater.

Claims (12)

In the rotor of the synchronous motor in which a ring-shaped magnet is arranged on the surface of the magnetic back yoke,
The magnet has a substantially circular outer peripheral surface,
The pole center, which is the center part of the magnetic pole, is thick, and the part between the poles where the magnetic pole changes is thin,
The synchronous motor rotor according to claim 1, further comprising a uniform thickness portion having a predetermined length in the circumferential direction and a uniform thickness in the radial direction at the pole center. In the rotor of the synchronous motor in which a ring-shaped magnet is arranged on the surface of the magnetic back yoke,
The magnet has a substantially circular outer peripheral surface,
The pole center, which is the center part of the magnetic pole, is thick, and the part between the poles where the magnetic pole changes is thin,
The synchronous motor rotor according to claim 1, further comprising a uniform thickness portion having a predetermined length in the circumferential direction and a uniform thickness in the radial direction at the inter-electrode portion. In the rotor of the synchronous motor in which a ring-shaped magnet is arranged on the surface of the magnetic back yoke,
The magnet
The pole center, which is the center part of the magnetic pole, is thick, and the part between the poles where the magnetic pole changes is thin,
The synchronous motor rotor according to claim 1, further comprising a small-diameter portion having an outer diameter smaller than an outer diameter at the pole center in the inter-electrode portion.   4. The synchronous motor rotor according to claim 3, wherein the small-diameter portion has a planar shape.   The synchronous motor rotor according to claim 4, wherein an inner peripheral plane portion parallel to the outer peripheral small-diameter portion is provided on an inner periphery of the interpolar portion.   The synchronous motor rotor according to claim 1, wherein a mixed material of iron powder and resin is used as a material of the back yoke.   The synchronous motor rotor according to claim 6, wherein the back yoke and the magnet are manufactured by integral molding.   A blower motor using the rotor of a synchronous motor according to any one of claims 1 to 7.   An air conditioner equipped with the blower motor according to claim 8.   A pump using the rotor of the synchronous motor according to claim 1.   11. The pump according to claim 10, wherein the material of the magnet is Sm-Fe-N.   A water heater using the pump according to claim 10 or 11.

Images