The present disclosure relates to a rotor, a motor, a blower and an air conditioner.
As a rotor used for a motor, there has been proposed a rotor including two types of permanent magnets (see Patent References 1 and 2, for example).
The rotor described in Patent References 1 and 2 includes a first permanent magnet supported by a rotary shaft and a second permanent magnet supported by an outer periphery of the first permanent magnet and having a magnetic pole stronger than a magnetic pole of the first permanent magnet. In Patent References 1 and 2, the second permanent magnet forms an outer circumference of the rotor. With this configuration, the magnetic flux amount of magnetic flux flowing from the rotor to the stator of the motor can be increased.
Patent Reference 1: Japanese Patent Application Publication No. 2005-151757
Patent Reference 2: Japanese Patent Application Publication No. 2011-087393
However, a permanent magnet having a strong magnetic pole is generally expensive. Thus, the manufacturing cost of the rotor increases in a case where the second permanent magnet having a magnetic pole stronger than a magnetic pole of the first permanent magnet forms the whole outer circumference of the rotor.
An object of the present disclosure is to secure a sufficient magnetic flux amount of magnetic flux generated in the rotor while reducing the manufacturing cost of the rotor.
A motor according to an aspect of the present disclosure includes a rotor and a stator. The rotor has a length in an axial direction which is longer than a length in the axial direction of a stator core of the stator. The rotor includes a rotary shaft, a first permanent magnet supported by the rotary shaft, and a second permanent magnet supported by an outer periphery of the first permanent magnet and having a magnetic pole stronger than a magnetic pole of the first permanent magnet. The second permanent magnet includes a plurality of magnet parts arranged at intervals in a circumferential direction of the first permanent magnet. A first width as a width in the circumferential direction of each of the plurality of magnet parts at a central part of the first permanent magnet in an axial direction of the rotary shaft is wider than a second width as a width in the circumferential direction of each of the magnet parts at an end part of the first permanent magnet in the axial direction. The first permanent magnet is split into a first split magnet part and a second split magnet part at a step part formed in the central part in the axial direction. Each magnet part has an overhang part that is fitted in the step part.
According to the present disclosure, a sufficient magnetic flux amount of magnetic flux generated in the rotor can be secured while reducing the manufacturing cost of the rotor.
A rotor, a motor, a blower and an air conditioner according to each embodiment of the present disclosure will be described below with reference to the drawings. The following embodiments are just examples and it is possible to appropriately combine the embodiments and appropriately modify each embodiment.
An xyz orthogonal coordinate system is shown as needed in each drawing in order to facilitate the understanding of descriptions regarding the configuration of the rotor or the like shown in the drawing. A z-axis is a coordinate axis parallel to an axis C1 of the rotor. An x-axis is a coordinate axis orthogonal to the z-axis. A y-axis is a coordinate axis orthogonal to both of the x-axis and the z-axis.
The rotor 1 includes a shaft 10 as a rotary shaft. The shaft 10 extends in the z-axis direction. In the following description, the z-axis direction is also referred to as an “axial direction”. The direction along a circumference of a circle centering at the axis C1 of the shaft 10 (for example, as shown by the arrow R1 in
The stator 9 includes a stator core 91 and a coil 92 wound on the stator core 91. The stator core 91 includes a yoke 91a in a ring shape about the axis C1 and a plurality of teeth 91b extending inward in the radial direction from the yoke 91a. The plurality of teeth 91b are arranged at equal angular intervals in the circumferential direction R1. A tip end part of each tooth 91b on the inner side in the radial direction faces an outer circumference la of the rotor 1 via the air gap G. While the number of teeth 91b is 12 in
As shown in
The ferrite bond magnet 20 is supported by the shaft 10. The ferrite bond magnet 20 contains a ferrite magnet and a resin. The resin contained in the ferrite bond magnet 20 is nylon resin, PPS (Poly Phenylene Sulfide) resin, epoxy resin or the like, for example.
The rare-earth bond magnet 30 is supported by an outer periphery 20a of the ferrite bond magnet 20. The rare-earth bond magnet 30 contains a rare-earth magnet and a resin. The rare-earth magnet is a neodymium magnet containing neodymium (Nd), iron (Fe) and boron (B), a samarium-iron-nitrogen magnet containing samarium (Sm), Fe and nitrogen (N), or the like, for example. The resin contained in the rare-earth bond magnet 30 is nylon resin, PPS resin, epoxy resin or the like, for example, similarly to the resin contained in the ferrite bond magnet 20.
The ferrite bond magnet 20 and the rare-earth bond magnet 30 differ from each other in strength (i.e., quantity of magnetism) of a magnetic pole. Specifically, the rare-earth bond magnet 30 has a magnetic pole stronger than a magnetic pole of the ferrite bond magnet 20. In other words, magnetic force of the rare-earth bond magnet 30 is greater than magnetic force of the ferrite bond magnet 20. Further, the ferrite bond magnet 20 and the rare-earth bond magnet 30 differ from each other in the linear expansion coefficient.
The ferrite bond magnet 20 is oriented to have polar anisotropy. Accordingly, the plurality of groove parts 21 include south pole groove parts 21a and north pole groove parts 21b. Namely, a plurality of groove parts 21a and 21b adjacent to each other in the circumferential direction R1 have magnetic poles different from each other in the polarity. The arc-like arrow F2 shown in
As shown in
The rare-earth bond magnet 30 includes a plurality of rare-earth magnet parts 31 as a plurality of magnet parts arranged at intervals in the circumferential direction R1. An outer periphery 31a of each of the plurality of rare-earth magnet parts 31 forms a part of the outer circumference la (see
Each of the plurality of rare-earth magnet parts 31 is oriented to have the polar anisotropy. A plurality of rare-earth magnet parts 31 adjacent to each other in the circumferential direction R1 have magnetic poles different from each other in the polarity. The arc-like arrows F3 shown in
The rare-earth magnet parts 31 are disposed in the groove parts 21 (see
In the first embodiment, the integral molding of the ferrite bond magnet 20 and the rare-earth bond magnet 30 means that the rare-earth bond magnet 30 is molded in a state in which the ferrite bond magnet 20 manufactured previously is placed in a mold. Thus, as compared to a configuration in which the ferrite bond magnet 20 is molded in a state in which the rare-earth bond magnet 30 (i.e., the plurality of rare-earth magnet parts 31) is placed in the mold, work of placing a plurality of (8 in the first embodiment) rare-earth magnet parts 31 in the mold can be eliminated, and therefore the productivity of the rotor body 50 can be increased.
As shown in
W1>W2 (1)
With this configuration, a magnetic pole of the rare-earth magnet part 31 at the central part 20c of the ferrite bond magnet 20 facing the stator core 91 in the radial direction is made stronger than a magnetic pole of the rare-earth magnet part 31 at the end part 20d of the ferrite bond magnet 20 in the axial direction. Therefore, a sufficient magnetic flux amount of the magnetic flux generated in the rotor 1 can be secured.
Here, when the length L1 of the rotor 1 in the axial direction is longer than the length L9 of the stator core 91 in the axial direction, there is a case where leakage flux is included in magnetic flux flowing from an end part of the rotor 1 in the axial direction (i.e., end part 1d shown in
As shown in
W21>W22 (2)
Further, the width W21 equals the first width W1 shown in
Next, a manufacturing method of the rotor 1 will be described with reference to
In step ST1, the rotor body 50 is formed. Incidentally, details of the step ST1 will be described later.
In step ST2, the rotor body 50 is connected to the shaft 10. In the first embodiment, the rotor body 50 is connected to the shaft 10 by integrating the rotor body 50 and the shaft 10 together via the resin part 60.
In step ST3, the rotor body 50 is magnetized by using the magnetizer, for example. Specifically, the ferrite bond magnet 20 and the rare-earth bond magnet 30 are magnetized so that the ferrite bond magnet 20 and the rare-earth bond magnet 30 have the polar anisotropy.
Next, the details of the process of forming the rotor body 50 (i.e., the step ST1 shown in
In step ST11, the inside of the first mold for molding the first ferrite magnet part 41 and the second ferrite magnet part 42 is filled with the material of the first ferrite magnet part 41 and the second ferrite magnet part 42. The first ferrite magnet part 41 and the second ferrite magnet part 42 are molded by injection molding, for example. Incidentally, the method of molding the first ferrite magnet part 41 and the second ferrite magnet part 42 is not limited to injection molding. The first ferrite magnet part 41 and the second ferrite magnet part 42 may be molded by a different molding method such as press molding.
In step ST12, the first ferrite magnet part 41 and the second ferrite magnet part 42 having predetermined shapes are molded while orienting the material of the first ferrite magnet part 41 and the second ferrite magnet part 42. In the step ST12, the first ferrite magnet part 41 and the second ferrite magnet part 42 are molded while orienting the material of the first ferrite magnet part 41 and the second ferrite magnet part 42 in a state in which a magnetic field having the polar anisotropy is generated inside the first mold by using the magnet for the orientation, for example. With this step, the ferrite bond magnet 20 having the polar anisotropy is molded. Further, in the step ST12, the molding is carried out so that an end face 41a of the first ferrite magnet part 41 and an end face 42a of the second ferrite magnet part 42 face the +z-axis direction.
In step ST13, the first ferrite magnet part 41 and the second ferrite magnet part 42 which are molded are cooled down.
In step ST14, the first ferrite magnet part 41 and the second ferrite magnet part 42 are taken out of the first mold.
In step ST15, the first ferrite magnet part 41 and the second ferrite magnet part 42 taken out in the step ST14 are demagnetized.
In step ST16, the first ferrite magnet part 41 and the second ferrite magnet part 42 are placed inside the second mold for the injection molding of the rare-earth bond magnet 30. In the step ST16, the first ferrite magnet part 41 and the second ferrite magnet part 42 are placed inside the second mold so that the end face 41a of the first ferrite magnet part 41 in the axial direction and the end face 42a of the second ferrite magnet part 42 in the axial direction contact each other. Namely, in the step ST16, the end face 41a of the first ferrite magnet part 41 is stuck to the end face 42a of the second ferrite magnet part 42 by inverting the first ferrite magnet part 41 molded in the step ST12 in the axial direction. Further, in the first embodiment, work of positioning the first ferrite magnet part 41 and the second ferrite magnet part 42 can be facilitated since the groove parts 21 are formed in the part of the ferrite bond magnet 20 where the end face 41a and the end face 42a contact each other (i.e., the central part 20c in the axial direction).
In step ST17, the groove parts 21 of the ferrite bond magnet 20 placed in the second mold are filled with the material of the rare-earth bond magnet 30. The rare-earth bond magnet 30 is molded by injection molding, for example. Incidentally, the method of molding the rare-earth bond magnet 30 is not limited to injection molding. The rare-earth bond magnet 30 may be molded by a different molding method such as press molding.
In step ST18, the rare-earth bond magnet 30 having a predetermined shape is molded while orienting the material of the rare-earth bond magnet 30. In the step ST18, the rare-earth bond magnet 30 (i.e., the plurality of rare-earth magnet parts 31) is molded while orienting the material of the rare-earth bond magnet 30 in a state in which a magnetic field having the polar anisotropy is generated inside the second mold by using the magnet for the orientation, for example. With this step, the rotor body 50 in which the ferrite bond magnet 20 and the rare-earth bond magnet 30 are molded integrally is formed.
In step ST19, the rotor body 50 formed in the step ST18 is cooled down.
In step ST20, the rotor body 50 cooled down is taken out of the second mold.
In step ST21, the rotor body 50 taken out in the step ST20 is demagnetized.
Next, a manufacturing cost of the rotor 1 according to the first embodiment will be described while making a comparison with a rotor 101a according to a first comparative example.
As shown in
In contrast, in the first embodiment, as shown in
Next, the surface magnetic flux density of the rotor 1 according to the first embodiment will be described while making a comparison with the rotor 101a according to the first comparative example and a rotor 101b according to a second comparative example.
As shown in
As shown in
As shown in
The distribution of the surface magnetic flux density in the central part 1c of the rotor 1 according to the first embodiment is represented by a waveform S12 of a substantially sinusoidal wave. In the central part 1c of the rotor 1 in the axial direction, while magnetic flux density equivalent to that in the rotor 101a according to the first comparative example is obtained in a magnetic pole central part (a north pole or a south pole), magnetic flux density slightly less than that in the rotor 101a according to the first comparative example is obtained in an inter-pole part (between the north pole and the south pole). This is because the first width W1 is wider than the second width W2 in the rare-earth magnet part 31 shown in
As described above, according to the first embodiment, the rare-earth bond magnet 30 includes a plurality of rare-earth magnet parts 31 arranged at intervals in the circumferential direction R1. The rare-earth bond magnet 30 is more expensive than the ferrite bond magnet 20. In the rotor 1 according to the first embodiment, since the rare-earth bond magnet 30 includes a plurality of rare-earth magnet parts 31 arranged at intervals in the circumferential direction R1, the amount of use of the rare-earth bond magnet 30 is reduced, and thus the manufacturing cost of the rotor 1 can be reduced.
Further, according to the first embodiment, the first width W1 as the width in the circumferential direction of each of the plurality of rare-earth magnet parts 31 in the central part 20c of the ferrite bond magnet 20 in the axial direction is wider than the second width W2 as the width in the circumferential direction of each rare-earth magnet part 31 in the end part 20d of the ferrite bond magnet 20 in the axial direction. With this configuration, the magnetic pole of the rare-earth magnet part 31 at the central part 20c of the ferrite bond magnet 20 facing the stator core 91 in the radial direction is made stronger than the magnetic pole of the rare-earth magnet part 31 at the end part 20d of the ferrite bond magnet 20 in the axial direction. Therefore, a sufficient magnetic flux amount of the magnetic flux flowing from the rotor 1 to the stator 9 can be secured while reducing the manufacturing cost of the rotor 1.
Here, when the length L1 in the axial direction of the rotor 1 is longer than the length L9 in the axial direction of the stator core 91 as shown in
Furthermore, according to the first embodiment, since the rare-earth bond magnet 30 includes a plurality of rare-earth magnet parts 31 arranged at intervals in the circumferential direction R1, an abrupt change in the surface magnetic flux density of the rotor 1 is inhibited, and thus the rotor 1 is capable of achieving inductive voltage equivalent to that of the rotor 101a according to the first comparative example. Thus, the rotor 1 according to the first embodiment is capable of achieving accuracy of rotation control equivalent to that of the rotor 101a according to the first comparative example.
Moreover, according to the first embodiment, the ferrite bond magnet 20 supported by the shaft 10 has the polar anisotropy. With this configuration, it is unnecessary to dispose a rotor core that forms a magnetic path on the inner side of the ferrite bond magnet 20 in the radial direction, and thus the number of components in the rotor 1 can be reduced and the weight of the rotor 1 can be reduced.
In addition, according to the first embodiment, the ferrite bond magnet 20 includes the first ferrite magnet part 41 and the second ferrite magnet part 42 aligned in the axial direction. In order to mold the ferrite bond magnet 20 including the groove parts 21 each having a shape corresponding to the shape of the rare-earth magnet part 31, namely, in order to mold the groove parts 21 in each of which the width W21 in the circumferential direction R1 in the central part 20c in the axial direction is wider than the width 22 in the circumferential direction R1 in the end part 20d in the axial direction, the mold needs to have a complicated structure. Thus, the facility for molding the ferrite bond magnet 20 gets expensive. In the first embodiment, the ferrite bond magnet 20 includes the first ferrite magnet part 41 and the second ferrite magnet part 42 divided from each other in the central part 20c in the axial direction. Accordingly, it is not necessary to use the mold for integrally molding the groove parts 21, and thus productivity of the ferrite bond magnet 20 can be increased.
As shown in
The first width W1 as a width in the circumferential direction R1 of each rare-earth magnet part 231 in the central part 20c of the ferrite bond magnet 20 in the axial direction is wider than the second width W2 as a width in the circumferential direction R1 of each rare-earth magnet part 231 in the end part 20d of the ferrite bond magnet 20 in the axial direction. With this configuration, the magnetic pole of the rare-earth magnet part 231 at the central part 20c of the ferrite bond magnet 20 is made stronger than the magnetic pole of the rare-earth magnet part 231 at the end part 20d of the ferrite bond magnet 20. Thus, a sufficient magnetic flux amount of the magnetic flux flowing from the rotor 2 to the stator 9 can be secured.
The rare-earth magnet part 231 includes a first part 231a and a plurality of second parts 231b and 231c connected to the first part 231a at positions on the outer side of the first part 231a in the axial direction. The first part 231a is a wider part having the first width W1 in the rare-earth magnet part 231. In the second embodiment, the width of the first part 231a in the circumferential direction is constant in the axial direction. Namely, in the second embodiment, the width of the first part 231a in the circumferential direction R1 (i.e., the first width W1) is constant in the axial direction.
The width of each of the plurality of second parts 231b and 231c in the circumferential direction R1 gradually increases toward the first part 231a. Namely, as the rotor 2 is viewed in the radial direction, the shape of the second part 231b is a trapezoidal shape. Incidentally, the width of the second part 231b in the circumferential direction R1 may also be constant in the axial direction. Further, the rare-earth magnet part 231 may also be configured to include only one of the plurality of second parts 231b and 231c.
The length L21 of the first part 231a in the axial direction is longer than the length L22 of the second part 231b, 231c in the axial direction. With this configuration, in the rare-earth magnet part 231, the magnetic pole of the rare-earth magnet part 231 at the central part 20c of the ferrite bond magnet 20 is made further stronger than the magnetic pole of the rare-earth magnet part 231 at the end part 20d of the ferrite bond magnet 20. Accordingly, it is made easier to secure a sufficient magnetic flux amount of the magnetic flux flowing from the rotor 2 to the stator 9.
As described above, according to the second embodiment, the rare-earth bond magnet 230 includes a plurality of rare-earth magnet parts 231 arranged at intervals in the circumferential direction R1. The rare-earth bond magnet 230 is more expensive than the ferrite bond magnet 20. In the rotor 2 according to the second embodiment, since the rare-earth bond magnet 230 includes a plurality of rare-earth magnet parts 231 arranged at intervals in the circumferential direction R1, the amount of use of the rare-earth bond magnet 230 is reduced, and thus the manufacturing cost of the rotor 2 can be reduced.
Further, according to the second embodiment, the first width W1 as the width in the circumferential direction of each of the plurality of rare-earth magnet parts 231 in the central part 20c of the ferrite bond magnet 20 in the axial direction is wider than the second width W2 as the width in the circumferential direction of each rare-earth magnet part 231 in the end part 20d of the ferrite bond magnet 20 in the axial direction. With this configuration, the magnetic pole of the rare-earth magnet part 231 at the central part 20c of the ferrite bond magnet 20 facing the stator core 91 in the radial direction is made stronger than the magnetic pole of the rare-earth magnet part 231 at the end part 20d of the ferrite bond magnet 20 in the axial direction. Therefore, a sufficient magnetic flux amount of the magnetic flux flowing from the rotor 2 to the stator 9 can be secured while reducing the manufacturing cost of the rotor 2. Furthermore, a sufficient magnetic flux amount of the magnetic flux flowing from the rotor 2 to the stator 9 can be secured without forming an overhang part 431f shown in
Moreover, according to the second embodiment, the rare-earth magnet part 231 includes the first part 231a and the second parts 231b and 231c connected to the first part 231a at positions on the outer side of the first part 231a in the axial direction. The first part 231a has the first width W1 which is constant in the axial direction. The length L21 of the first part 231a in the axial direction is longer than the length L22 of the second part 231b, 231c in the axial direction. With this configuration, the magnetic pole of the rare-earth magnet part 231 at the central part 20c of the ferrite bond magnet 20 is made further stronger than the magnetic pole of the rare-earth magnet part 231 at the end part 20d of the ferrite bond magnet 20. Accordingly, it is made easier to secure a sufficient magnetic flux amount of the magnetic flux flowing from the rotor 2 to the stator 9.
As shown in
In
W3>W4 (3)
With this configuration, a joint area of the ferrite bond magnet 20 and the rare-earth bond magnet 330 increases. Accordingly, falling off of the rare-earth bond magnet 330 from the ferrite bond magnet 20 can be prevented even when peeling occurs at the interface between the ferrite bond magnet 20 and the rare-earth bond magnet 330 due to expansion or contraction caused by a temperature change or centrifugal force acting on the rotor 3.
As above, in the third embodiment, the third width W3 is wider than the fourth width W4 in the rare-earth magnet part 331, and thus each groove part 221 of the ferrite bond magnet 20 in which the rare-earth magnet part 331 is disposed is a dovetail groove.
As described above, according to the third embodiment, the third width W3 as the width in the circumferential direction of the innermost part 331c of the rare-earth magnet part 331 in the radial direction is wider than the fourth width W4 as the width in the circumferential direction of the outermost part 331dof the rare-earth magnet part 331 in the radial direction. With this configuration, the joint area of the ferrite bond magnet 20 and the rare-earth bond magnet 330 increases. Accordingly, the falling off of the rare-earth bond magnet 330 from the ferrite bond magnet 20 can be prevented even when peeling occurs at the interface between the ferrite bond magnet 20 and the rare-earth bond magnet 330 due to expansion or contraction caused by a temperature change or centrifugal force acting on the rotor 3.
As shown in
The ferrite bond magnet 420 includes a first ferrite magnet part 441 and a second ferrite magnet part 442 aligned in the axial direction. A step part 420f is formed in a central part 420c of the ferrite bond magnet 420 in the axial direction. The step part 420f is recessed from an outer periphery 420a toward an inner circumference 420b of the ferrite bond magnet 420. The step part 420f is formed by a first step part 441f formed in the first ferrite magnet part 441 and a second step part 442f formed in the second ferrite magnet part 442. The first step part 441f is formed at an end face 441a of the first ferrite magnet part 441 in the axial direction in contact with the second ferrite magnet part 442. The second step part 442f is formed at an end face 442a of the second ferrite magnet part 442 in the axial direction in contact with the first ferrite magnet part 441.
The rare-earth bond magnet 430 includes a plurality of rare-earth magnet parts 431 arranged at intervals in the circumferential direction R1. The rare-earth magnet part 431 includes an overhang part 431f formed in a central part 431c in the axial direction facing the stator core 91 (see
The overhang part 431f and the step part 420f are joined to each other. With this configuration, the joint area of the ferrite bond magnet 420 and the rare-earth bond magnet 430 increases. Accordingly, the falling off of the rare-earth bond magnet 430 from the ferrite bond magnet 420 can be prevented even when peeling occurs at the interface between the ferrite bond magnet 420 and the rare-earth bond magnet 430 due to expansion or contraction caused by a temperature change or centrifugal force acting on the rotor 4.
As described above, according to the fourth embodiment, the rare-earth magnet part 431 includes the overhang part 431f formed in the central part 431c in the axial direction facing the stator core 91 in the radial direction. With this configuration, in the rare-earth magnet part 431, the magnetic pole of the rare-earth magnet part 431 at the central part 420c of the ferrite bond magnet 420 is made further stronger than the magnetic pole of the rare-earth magnet part 431 at the end part 420d of the ferrite bond magnet 420. Accordingly, the magnetic flux amount of the interlinkage magnetic flux flowing from the rotor 4 to the coil 92 can be increased. Namely, the magnetic flux amount of effective magnetic flux necessary for the driving of the motor can be increased.
Further, according to the fourth embodiment, the overhang part 431f of the rare-earth magnet part 431 and the step part 420f of the ferrite bond magnet 420 are joined to each other. With this configuration, the joint area of the ferrite bond magnet 20 and the rare-earth bond magnet 30 increases. Accordingly, the falling off of the rare-earth bond magnet 430 from the ferrite bond magnet 420 can be prevented even when peeling occurs at the interface between the ferrite bond magnet 420 and the rare-earth bond magnet 430 due to expansion or contraction caused by a temperature change or centrifugal force acting on the rotor 4.
As shown in
As shown in
A fifth width W5 as the width of the overhang part 531f in the circumferential direction R1 is wider than the first width W1 of the rare-earth magnet part 531 in the circumferential direction R1. Here, the “width of the overhang part 531f in the circumferential direction R1” is the length of a straight line extending in the overhang part 531f in a direction orthogonal to a straight line M connecting the axis C1 and the overhang part 531f.
As described above, according to the fifth embodiment, the width W5 of the overhang part 531f of the rare-earth magnet part 531 in the circumferential direction R1 is wider than the first width W1 of the rare-earth magnet part 531. With this configuration, the joint area of the overhang part 531f and the central part 420c of the ferrite bond magnet 420 in the axial direction increases, and thus the rare-earth bond magnet 530 is further less likely to fall off from the ferrite bond magnet 420.
As shown in
The rare-earth bond magnet 630 includes rare-earth magnet parts 631. The rare-earth magnet part 631 includes an overhang part 631f. The overhang part 631f includes a first convex part 631g that is fitted in the first concave part 641g and a second convex part 631h that is fitted in the second concave part 642g. With this configuration, the rare-earth bond magnet 630 is further less likely to fall off from the ferrite bond magnet 620. Since the overhang part 631f includes the first convex part 631g and the second convex part 631h as above, the length in the axial direction of an inner circumferential side of the overhang part 631f where the first convex part 631g and the second convex part 631h are formed is longer than the length in the axial direction of an outer circumferential side of the overhang part 631f.
As described above, in the rotor 6 according to the sixth embodiment, the first convex part 631g of the overhang part 631f of the rare-earth magnet part 631 is fitted in the first concave part 641g formed in the first step part 441f of the ferrite bond magnet 620. With this configuration, the rare-earth bond magnet 630 is further less likely to fall off from the ferrite bond magnet 620.
Further, in the rotor 6 according to the sixth embodiment, the second convex part 631h of the overhang part 631f is fitted in the second concave part 642g formed in the second step part 442f of the ferrite bond magnet 620. With this configuration, the rare-earth bond magnet 630 is further less likely to fall off from the ferrite bond magnet 620.
As shown in
The rare-earth bond magnet 730 includes a plurality of rare-earth magnet parts 731 arranged at intervals in the circumferential direction R1 and a connection part 732 connecting rare-earth magnet parts 731 adjoining in the circumferential direction R1 among the plurality of rare-earth magnet parts 731. The rare-earth magnet part 731 includes an overhang part 731f formed in a central part 731c in the axial direction. The overhang part 731f and a concave part 20f formed in the central part of the ferrite bond magnet 20 in the axial direction are joined to each other. In
The connection part 732 connects the overhang parts 731f of rare-earth magnet parts 731 adjoining in the circumferential direction R1. This increases rigidity of the rare-earth bond magnet 730, and thus the rare-earth bond magnet 730 is further less likely to fall off from the ferrite bond magnet 20. The connection part 732 and the concave part 20f of the ferrite bond magnet 20 are joined to each other.
As described above, according to the seventh embodiment, the rare-earth bond magnet 730 includes the connection part 732 connecting rare-earth magnet parts 731 adjoining in the circumferential direction R1 among the plurality of rare-earth magnet parts 731 arranged at intervals in the circumferential direction R1. With this configuration, the rigidity of the rare-earth bond magnet 730 increases, and thus the rare-earth bond magnet 730 is further less likely to fall off from the ferrite bond magnet 20.
As shown in
Each of the ring members 81 and 82 is a member having a ring shape about at the axis C1. The ring members 81 and 82 are formed of a resin such as unsaturated polyester resin, for example.
The ring member 81 is situated on the +z-axis side relative to the ferrite bond magnet 20 and the rare-earth bond magnet 30. The ring member 81 is fixed to an end face 20j of the ferrite bond magnet 20 facing the +z-axis direction and end faces 31j of the rare-earth magnet parts 31 facing the +z-axis direction.
The ring member 82 is situated on the −z-axis side relative to the ferrite bond magnet 20 and the rare-earth bond magnet 30. The ring member 82 is fixed to an end face 20k of the ferrite bond magnet 20 facing the −z-axis direction and end faces 31k of the rare-earth magnet parts 31 facing the −z-axis direction. Incidentally, the rotor 8 may also be configured to include only one of the plurality of ring members 81 and 82.
As described above, according to the eighth embodiment, the rotor 8 includes the ring member 81 fixed to the end face 20j of the ferrite bond magnet 20 facing the +z-axis direction and the end faces 31j of the rare-earth magnet parts 31 facing the +z-axis direction. With this configuration, the rare-earth magnet parts 31 are connected to the ferrite bond magnet 20 via the ring member 81, and thus the rare-earth magnet parts 31 are less likely to fall off from the ferrite bond magnet 20.
Further, the rotor 8 according to the eighth embodiment includes the ring member 82 fixed to the end face 20k of the ferrite bond magnet 20 facing the −z-axis direction and the end faces 31k of the rare-earth magnet parts 31 facing the −z-axis direction. With this configuration, the rare-earth magnet parts 31 are connected to the ferrite bond magnet 20 via the plurality of ring members 81 and 82, and thus the rare-earth magnet parts 31 are less likely to fall off from the ferrite bond magnet 20.
As shown in
The resin part 60A includes the inner cylinder part 61 supported by the shaft 10, an outer cylinder part 62A fixed to the inner circumference 20b of the ferrite bond magnet 20, and a plurality of ribs 63A connecting the inner cylinder part 61 and the outer cylinder part 62A.
The ring members 81A and 82A are connected to the resin part 60A (specifically, the outer cylinder part 62A and the ribs 63A). In the first modification of the eighth embodiment, the ring members 81A and 82A are connected to the outer cylinder part 62A of the resin part 60A by means of integral molding. Namely, in the first modification of the eighth embodiment, the shaft 10, the ferrite bond magnet 20 and the rare-earth bond magnet 30 are connected together via the resin part 60A and the ring members 81A and 82A.
As described above, according to the first modification of the eighth embodiment, in the rotor 8A, the ring members 81A and 82A are connected to the resin part 60A. With this configuration, when the shaft 10 and the ferrite bond magnet 20 are integrally molded via the resin part 60A made of a resin, the ring members 81A and 82A can also be molded at the same time, and thus manufacturing steps of the rotor 8A can be reduced.
Here, the natural frequency of the rotor 8A changes depending on the rigidity of the rotor 8A. The rigidity of the rotor 8A can be adjusted by changing the width in the circumferential direction R1 and the length in the radial direction of the rib 63A and the number of ribs 63A in the resin part 60A, for example. In the first modification of the eighth embodiment, the length in the radial direction of each rib 63A is increased since the ribs 63A are connected to the ring members 81A and 82A. Accordingly, the rigidity of the rotor 8A can be changed. Namely, the natural frequency of the rotor 8A can be changed. Thus, the occurrence of resonance can be inhibited and vibrational characteristics of the rotor 8A can be adjusted.
Further, the inertia moment of the rotor 8A changes depending on the mass of the rotor 8A. The mass of the rotor 8A can be adjusted by changing the width in the circumferential direction R1 and the length in the radial direction of the rib 63A and the number of ribs 63A. With the increase in the inertia moment, the rotation of the rotor 8A can be more stabilized although higher starting torque is needed. In the first modification of the eighth embodiment, the length in the radial direction of each rib 63A is increased since the ribs 63A are connected to the ring members 81A and 82A as described above. With this configuration, the inertia moment of the rotor 8A can be increased. As above, in the first modification of the eighth embodiment, the natural frequency and the inertia moment of the rotor 8A can be adjusted since the ring members 81A and 82A are connected to the resin part 60A.
The indoor unit 910 includes an indoor blower 911 as a blower and a housing 912 that covers the indoor blower 911. The indoor blower 911 includes the motor 100 and an impeller 911a fixed to the shaft 10 of the motor 100. The impeller 911a is driven by the motor 100 to generate an airflow. The impeller 911a is a cross-flow fan, for example.
The outdoor unit 920 includes an outdoor blower 921 as a blower, a compressor 922, and a housing 923 that covers the outdoor blower 921 and the compressor 922. The outdoor blower 921 includes the motor 100 and an impeller 921a fixed to the shaft 10 (see
As described above, in the air conditioner 900 according to the ninth embodiment, the motor 100 according to the first embodiment is applied to the indoor blower 911 and the outdoor blower 921. In the motor 100 according to the first embodiment, the interlinkage magnetic flux flowing from the rotor 1 to the coil 92 (see
Incidentally, the motor 100 may also be provided in only one of the indoor blower 911 and the outdoor blower 921. Further, the motor 100 may also be applied to the motor 922a of the compressor 922. Furthermore, the motor 100 according to the ninth embodiment may be installed not only in the air conditioner 900 but also in equipment of a different type.
This application is a U.S. national stage application of International Patent Application No. PCT/JP2020/034033 filed on Sep. 9, 2020, the disclosure of which is incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/JP2020/034033 | 9/9/2020 | WO |