Magnetization device

Abstract

To realize a magnetizing device capable of increasing magnetism to a magnet by loading a magnetic flux over a wide range of the magnet without increasing a voltage.SOLUTION: A magnetizing device is a magnetization device that magnetizes a magnet 18 disposed in a rotor 16 of a motor 12, and comprises a coil 20. The coil 20 passes through a pair of through holes 22 provided in the rotor 16 with a predetermined interval, and winds a portion 24 of the rotor sandwiched between the pair of through holes 22.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a magnetizing device that magnetizes a magnet arranged in a rotor of a motor. [Background technology]

[0002] The manufacturing process for rotors, which are one of the components of motors, includes a magnetization process in which the magnets placed on the rotor are magnetized. Insufficient magnetization can lead to a deterioration in motor performance, so technologies have been proposed for sufficiently and efficiently magnetizing the entire magnet.

[0003] For example, Patent Document 1 discloses a magnetizing device that includes a first magnetizing portion provided on the outside of a rotor and a second magnetizing portion inserted into a hole that penetrates the rotor. This magnetizing device magnetizes the magnet from the outside and inside using the first and second magnetizing portions, respectively, and is said to be able to sufficiently magnetize the entire magnet on the rotor on which the magnet is placed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-29265 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the voltage required for magnetization varies depending on the size of the rotor, and if the rotor is large, there may be a problem of insufficient voltage. One possible solution to avoid this situation would be to increase the power supply equipment, but it is desirable to avoid the increased costs associated with investing in such power supply equipment as much as possible.

[0006] Furthermore, if a conventional magnetizing device does not use an iron core, a large magnetic flux is not generated in the rotor, and the magnets arranged in the rotor may not be sufficiently magnetized.

[0007] Therefore, this specification provides a magnetizing device that can apply magnetic flux to a wide range of a magnet and improve the magnetization of the magnet without increasing the voltage. [Means for solving the problem]

[0008] The magnetizing device disclosed in this specification is a magnetizing device that magnetizes a magnet placed on a rotor of a motor, and is characterized in that it includes a coil that passes through a pair of through holes provided in the rotor at a predetermined interval and winds around the portion of the rotor sandwiched between the pair of through holes. [Effects of the Invention]

[0009] According to the magnetizing device disclosed in this specification, by passing a current through the coil, the portion of the rotor sandwiched between the pair of through holes through which the coil passes functions as a yoke. In other words, the rotor portion itself can be used as a magnetizing yoke, making it easier to effectively generate a strong magnetic flux. As a result, the generated magnetic flux magnetizes a wide area of the magnet, making it possible to sufficiently magnetize the magnet with a relatively low voltage. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a plan view schematically showing a magnetization device. [Figure 2] FIG. 2 is a diagram schematically illustrating a part of a rotor of the magnetizing device according to the embodiment. [Figure 3] FIG. 10 is a diagram schematically illustrating a part of a rotor of a conventional magnetizing device. DETAILED DESCRIPTION OF THE INVENTION

[0011] The magnetizing device will be described below with reference to the drawings.

[0012] FIG. 1 is a plan view schematically showing a magnetization device. FIG. 1 shows a magnetization device 10 and a motor 12. The motor 12 includes an annular stator 30, a rotor 16 arranged inside the stator 30 with a gap therebetween, and a shaft 14 located at the center of the rotor 16. By supplying a predetermined current to multi-phase (e.g., three-phase) coils (not shown) arranged in the stator 30, a rotating magnetic field is formed, causing the rotor 16 to rotate. The magnetization device 10 is a device that magnetizes magnets 18 arranged in the rotor 16, which is one of the components of the motor 12.

[0013] As shown in Fig. 1, rotor 16 has a total of three magnets 18 arranged in a substantially triangular shape: two magnets 18a arranged diagonally relative to the radial direction of rotor 16 and one magnet 18b arranged along the outer periphery of rotor 16. Rotor 16 is provided with multiple sets of these three magnets 18. Note that hereinafter, unless there is any need to distinguish between magnets 18a and 18b, they will be simply referred to collectively as magnets 18. Rotor 16 is formed, for example, by laminating a large number of electromagnetic steel sheets, and magnets 18 are fixed in magnet holes formed in the laminate of electromagnetic steel sheets.

[0014] As shown in Fig. 1, the magnetization device 10 includes a coil 20. The coil 20 is arranged to pass through a pair of through holes 22 provided in the rotor 16. The coil 20 is also arranged radially inward of the magnet 18 of the rotor 16. Note that in Fig. 1 and the following Figs. 2 and 3, the coil 20 is indicated by a lightly shaded portion.

[0015] In FIG. 1, an area including the area in the rotor 16 where the three magnets 18 are arranged in a substantially triangular shape and the area where the coil 20 is arranged, passing through a pair of through holes 22 arranged inside the three magnets 18 in the radial direction of the rotor 16, is surrounded by a two-dot chain line A and shown as an enlarged view. This area A corresponds to one magnetic pole of the rotor 16. Magnetization of the magnet 18 in the area corresponding to one magnetic pole of the rotor 16 will be described below using FIG. 2 and FIG. 3 as a comparative example. Note that in FIGS. 2 and 3, the same components as in FIG. 1 are denoted by the same reference numerals, and their description will be omitted where appropriate.

[0016] Fig. 2 is a diagram schematically showing a part of a rotor of a magnetizing device according to the embodiment. Fig. 3 is a diagram schematically showing a part of a rotor of a conventional magnetizing device. Figs. 2 and 3 are both a plan view and a cross-sectional view of rotor 16.

[0017] First, a conventional magnetization device 10a shown in FIG. 3, which is one of the comparative examples, will be described. As shown in FIG. 3, similar to FIG. 1, three magnets 18 are arranged in a substantially triangular shape on the rotor 16, and through holes 22 are provided inside the three magnets 18 in the radial direction of the rotor 16. Here, the difference between FIG. 1 and FIG. 3 is that the through hole 22 shown in FIG. 3 is provided in only one location in a portion of the rotor 16 corresponding to one magnetic pole. Note that, although there is only one through hole 22 in this conventional example, the number is not particularly limited. A characteristic of the conventional example is that the through hole 22 is provided in a location approximately in the center of one magnetic pole, as shown in FIG. 3.

[0018] A coil 20 is inserted into this through hole 22. As shown in the CC cross section surrounded by the two-dot chain line, this coil 20 is inserted into the through hole 22, which is a closed space. When a current (shown by the hollow arrow in FIG. 3) flows from a power supply (not shown) to the coil 20, a magnetization yoke 26 is created. The magnetic flux generated by this magnetization yoke 26 is shown by the black arrow in FIG. 3, but it is in a narrow range. In other words, with the structure of the magnetizer 10a as shown in FIG. 3, it is not possible to generate magnetic flux over a wide range (in other words, it is difficult to generate strong magnetic flux), and even if the magnet 18 is magnetized by this generated magnetic flux, it may not be sufficiently magnetized.

[0019] On the other hand, the magnetizing device 10 disclosed in this specification shown in Figure 2 has a structure in which magnetic flux is applied to a wider range of the magnet 18. This will be explained in detail below.

[0020] As described with reference to FIG. 1 , in the magnetization device 10 shown in FIG. 2 , three magnets 18 are arranged in a substantially triangular shape in the rotor 16, and a pair of through holes 22 is provided inside the three magnets 18 in the radial direction of the rotor 16. As shown in FIG. 2 , the pair of through holes 22 is located outside the inner diameter end of the magnet 18. In FIG. 2 , a cross section of the pair of through holes 22 is shown as a B-B cross section surrounded by a two-dot chain line. As shown in FIG. 2 and the B-B cross section, the pair of through holes 22 are arranged at a predetermined interval. A coil 20 is provided so as to pass through the pair of through holes 22 and surround a portion 24 of the rotor 16 sandwiched between the pair of through holes 22 (hereinafter referred to as the “rotor portion 24”). The coil 20 is designed to be fixed above the through holes 22 with bolts or the like so that a current can flow through it. In FIG. 2 , the portion fixed by the bolts is indicated by a dashed line. With this configuration, one turn can be formed by inserting the U-shaped lower portion of coil 20 into through-hole 22 from below and connecting one end of the straight upper portion of coil 20. In the illustrated example, only one turn of coil 20 is shown, but a spiral coil with two or more turns can be formed by sequentially connecting one end of one lower portion to the other end of an adjacent lower portion with an upper portion. Furthermore, one end of coil 20 is connected to the + side of a power supply (not shown), and the other end is connected to the - side.

[0021] With the above configuration, when a direct current (shown by the open arrow in FIG. 2 ) is applied to the coil 20 from a power supply (not shown), the portion 24 of the rotor functions as a magnetizing yoke. That is, the magnet 18 is magnetized by the magnetic flux generated in the portion 24 of the rotor functioning as the magnetizing yoke. The magnetic flux generated in the portion 24 of the rotor is indicated by the black arrow in FIG. 2 . As is clear from a comparison of the range of magnetic flux shown in FIG. 2 with the range of magnetic flux shown in FIG. 3 , the magnetic flux generated by the magnetizing device 10 shown in FIG. 2 is wider (i.e., a stronger magnetic flux is generated), enabling sufficient magnetization of the magnet 18. In other words, in the past, when the rotor 16 was large, problems such as insufficient voltage occurred or insufficient magnetization occurred at the ends of the magnet. However, the magnetizing device 10 can generate a stronger magnetic flux over a wider range, enabling sufficient magnetization of the magnet 18.

[0022] The spacing between the pair of through holes 22 provided in the rotor 16 is determined according to the width of one magnetic pole of the rotor 16. That is, by providing the pair of through holes 22 corresponding to the width of the magnetic pole, the magnetic flux generated in the part 24 of the rotor can be made to cover a wide range. Furthermore, unlike the conventional magnetizing device 10a shown in FIG. 3, the magnetizing device 10 does not need to have a magnetizing yoke itself, and therefore has a simpler design as a device. That is, in the magnetizing device 10 according to the embodiment, the part of the rotor 16 itself can be used as a magnetizing yoke, making it easier to effectively generate a strong magnetic flux.

[0023] The above description is merely an example, and the magnetization device disclosed in this specification may be configured such that a coil passes through a pair of through-holes provided in the rotor at a predetermined interval and the coil is wound around the portion of the rotor sandwiched between the pair of through-holes. Therefore, other configurations may be modified as appropriate. For example, in the embodiment, three magnets 18 are arranged in a substantially triangular shape on the rotor 16, but the number and arrangement of the magnets are not limited to this. Furthermore, the pair of through-holes 22 are arranged outside the inner diameter end of the magnet 18 to generate magnetic flux over a wide area corresponding to the width of the magnetic poles, but this is not particularly limited. [Explanation of symbols]

[0024] 10,10a magnetization device, 12 motor, 14 shaft, 16 rotor, 18 magnet, 20 coil, 22 through hole, 24 part of rotor, 26 magnetization yoke.

Claims

[Claim 1] A magnetizing device for magnetizing a magnet disposed in a rotor of a motor, A coil is provided. The coil passes through a pair of through holes provided in the rotor at a predetermined interval and is wound around a portion of the rotor sandwiched between the pair of through holes. A magnetizing device characterized by:

Images