JPH0465625B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a rotating electrical machine having a permanent magnet in its rotor.

[Background of the Invention] Recently, rotating electric machines having a structure in which permanent magnets are attached to the surface of the rotor core have been disclosed in Japanese Patent Application Laid-Open No. 177263/1983 and Utility Model Application No. 1987-177263.
−20104, Utility Model No. 50-20105, Utility Model No. 20106,
It has been proposed in Japanese Patent Application Laid-Open No. 120159/1983.

Permanent magnets do not have very good moldability, nor are their workability very good. Also, since it is harder and more brittle than iron, the problem is how to attach it to the rotor core, and the measures described in the above-mentioned publications are countermeasures to this problem. Eddy currents are generated in the parts provided to fix these permanent magnets, causing a reduction in efficiency.

Conventional examples improved from this are shown in FIGS. 1 and 2. This conventional example is a four-pole rotating electric machine. 1 is a rotating shaft, and 2 is a rotor core. This rotor core 2
is constructed by laminating a large number of punched iron plates 3 in the axial direction of the rotating shaft 1 and preventing rotation with respect to the rotating shaft 1. Several plates 3a located at both ends of the punched iron plate 3 have an outer diameter larger than that of the plates 3b located at the center. In addition, in order to prevent the permanent magnets 4a to 4d from shifting in the circumferential direction, a protrusion 5 extending in the axial direction of the same number as the number of permanent magnet members 4a to 4d is provided on the portion of the rotor core 3 constituted by 3b. be. A portion of the rotor core 3 formed by 3b located between adjacent protrusions 5 is formed on an arc concentric with the rotating shaft 1. Permanent magnet structures 4a to 4d each having an arcuate cross section are provided on the surface of each of the arcuate portions. Among the permanent magnet materials, 4a and 4c are magnetized so that their outer surfaces exhibit north poles, and 4b and 4d are magnetized so that their outer surfaces exhibit south poles. A sleeve 6 whose main component is synthetic resin is fitted to tightly surround the permanent magnets 4a to 4d. That is, the permanent magnets 4a to 4d are tightly interposed between the rotor core 2 and the sleeve 6. Several axially penetrating holes 7 are provided between the inner and outer surfaces of the rotor core 2. Aluminum, zinc or The rotor core 2 and permanent magnet 4a are made by pouring hot water containing these as the main ingredients.
~4d and sleeve 6 are integrated. There are 8
It is shown. In this case, since the sleeve 6 is placed inside the die casting machine, it must be able to withstand the temperature during die casting.

This conventional example has solved the problem of reduced efficiency due to eddy current, the ease of positioning the sleeve in the axial direction during assembly, the elongation of the sleeve when it gets hot, and the sleeve's ability to withstand high temperatures during die casting. No particular consideration was given to heat resistance, etc. For this reason, many man-hours are required to fix the permanent magnets to the rotor, and problems such as misalignment of the sleeve and heat resistance of the sleeve remain unsolved.

[Object of the Invention] The present invention has been made in view of the above points, and its object is to attach a sleeve mainly made of synthetic resin to the stator in order to fix the permanent magnets of the rotor. A rotating electrical machine with a rotor that is easy to assemble, has a stable fixation of the sleeve even at high temperatures, and can be assembled in such a way that the sleeve is not exposed to the high heat of die casting. It is on offer.

[Summary of the Invention] That is, the present invention relates to a structure for attaching a cylindrical sleeve made of synthetic resin as a main component to fix a permanent magnet material attached to the outer peripheral surface of a rotor core. At both ends of the die-cast rotor structure, the outer diameter of one end of the die-cast is smaller than the inner diameter of the sleeve,
Further, the outer diameter of the other end of the die casting is configured to be larger than the inner diameter of the sleeve.

As a result, when installing the sleeve, after the die casting process, prepare a sleeve previously formed into a cylindrical shape, insert it into one end of the die cast smaller than the inner diameter of the sleeve, and insert it into the other end of the die cast larger than the inner diameter of the sleeve. It can be positioned by touching the end. In addition, even if the rotor becomes hot and there is a gap between the permanent magnet and the sleeve, the other end of the die cast, which is larger than the inner diameter of the sleeve, acts as a stopper to prevent the die cast from shifting toward the other end. become.

[Embodiment of the Invention] FIG. 3 shows an embodiment of the present invention. This embodiment is a four-pole rotating electric machine. Further, the cross-sectional view corresponding to FIG. 2 is the same as FIG. 2. The configuration of the embodiment will be explained below with reference to FIGS. 2 and 3.

1 is a rotating shaft, and 2 is a rotor core. The rotor core 2 is constructed by laminating a large number of punched iron plates 3 in the axial direction of the rotating shaft 1 and preventing rotation with respect to the rotating shaft 1. Several plates 3a located at both ends of the punched iron plate 3 have outer diameters located in the center.
It is larger than b. In addition, permanent magnet materials 4a to 4d are provided in the portion 3b of the rotor core 3 in order to prevent the permanent magnet materials 4a to 4d from shifting in the circumferential direction.
The same number of protrusions 5 as 4d are provided that extend in the axial direction. A portion of the rotor core 3 formed by 3b located between adjacent protrusions 5 is formed on an arc concentric with the rotating shaft 1. Permanent magnet components 4a to 4 having an arc-shaped cross section are provided on the surface of each of the arc-shaped parts.
d is provided. Among the permanent magnet materials, 4a and 4c are magnetized so that their outer surfaces exhibit north poles, and 4b and 4d are magnetized so that their outer surfaces exhibit south poles. Permanent magnet 4a~
A sleeve 6 whose main component is synthetic resin is fitted to tightly surround 4d. In other words, the permanent magnet 4a~
4d is tightly interposed between the rotor core 2 and the sleeve 6. The hardness of the sleeve is E78.
~ M110 or so, and the wall thickness is 0.5 for a rotor with an outer diameter of 50 mm.
It is about mm to 2.0 mm.

This embodiment is almost the same as the conventional example shown in FIGS. 1 and 2, but the sleeve attachment structure is different.

In this embodiment, after die casting is completed, the sleeve 6 is tightly fitted by applying an epoxy, polyamide, polyimide, or polyamide-imide adhesive to the inside thereof. Therefore, the diameter of the die-cast part 8a on one side of the rotor core 2 is made slightly smaller than the inner diameter of the sleeve 6 so that the sleeve 6 can be covered thereon. The other end 8b of the die-cast part 8 is designed to abut against the end of the sleeve 6, so the end 8b functions to position the sleeve 6. Also, when the rotor is used with the rotor standing above 8a or 8b, the end 8
b fulfills the function of preventing the sleeve 6 from falling. Also,
End 8b can allow the sleeve to stretch when the rotor becomes hot.

By the way, the coefficient of thermal expansion of the iron that makes up the rotating shaft 1 and the rotor core 2, the silicon steel plate, and the ferrite that makes up the permanent magnets 4a to 4d is approximately the same value, 10×10 ^-6 to 15×. It is about 10 ^-6 . In contrast, ordinary epoxy, polyimide, polyamide,
Alternatively, the coefficient of thermal expansion of polyamideimide and the like is much larger, about 100×10 ⁻⁶ . Considering that the surface temperature of the rotor rises at about 100℃, the outer diameter
For a 50mm rotor, there will be an expansion difference of approximately 0.45mm. Therefore, the distance between the rotor and the stator (not shown) is determined taking into account the above-mentioned expansion difference.

Recently, a polyimide-based resin with a low coefficient of thermal expansion, called the product name of low thermal expansion polyimide "X-95", has been developed, so if this resin is used, the gap between the rotor and stator can be made smaller. can do. In addition, even when the sleeve is made of ordinary resin as mentioned above, Ceratsumi powder,
It is preferable to mix short glass fibers, etc., because the coefficient of thermal expansion becomes smaller and the strength increases. In particular, if carbon fiber is mixed, since carbon fiber has a negative coefficient of thermal expansion, the coefficient of thermal expansion of the sleeve can be made considerably small.

Several axially penetrating holes 7 are provided between the inner and outer surfaces of the rotor core 2. Inside this hole 7 and between the permanent magnets 4a to 4d adjacent to both ends of the rotor core 2, and between the rotor core 2 and the permanent magnets 4a to 4d, aluminum, zinc, or hot water containing these as the main component is poured. Take a look at the rotor core 2,
The permanent magnets 4a to 4d are integrated. The insertion part is indicated by 8.

Note that the spaces between the electromagnets, between the rotor core and the electromagnets, and between the electromagnets and the sleeve may be filled by injecting or impregnating synthetic resin.

[Effects of the Invention] As is clear from the above description, according to the present invention, at both ends of the die cast die cast through the outer part of the rotor core, the inner diameter of the sleeve is equal to the outer diameter of one end of the die cast. Since the outer diameter of the other end of the die casting is larger than the inner diameter of the sleeve, a sleeve formed into a cylindrical shape is prepared in advance when installing the sleeve. However, this can be positioned by inserting it from one end of the die cast smaller than the inner diameter of the sleeve and hitting the other end of the diamond cast larger than the inner diameter of the sleeve, which has the effect of improving positioning accuracy. Moreover, since it can be assembled in this manner, it can be assembled quickly, which has the effect of shortening the assembly time. Also, when automating, the positioning means is built into the rotor itself, so
This has the advantage that the device can be easily configured.

Although it is not preferable to expose a sleeve whose main component is synthetic resin to high heat during die casting, according to the present invention, since the rotor is constructed as described above, the sleeve installation process is performed after the die casting process. This has the effect that the sleeve can be assembled without being exposed to high heat during die casting.

Also, even if the rotor becomes hot and there is a gap between the permanent magnet and the sleeve, the other end of the die cast, which is larger than the inner diameter of the sleeve, will act as a stopper.
This has the effect of not coming off at least toward the other end of the die cast.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view for explaining the structure of a conventional rotor having permanent magnets. Figure 2 is the first
FIG. 2 is a cross-sectional view taken along line 2-2. FIG. 3 is a longitudinal sectional view of a rotor showing an embodiment of the present invention. 1: Rotor, 2: Rotor core, 4a to 4d: Permanent magnet, 6: Sleeve.

Claims (1)

[Scope of Claims] 1. A rotating shaft, a rotor core that is attached to the rotating shaft and has an outer peripheral surface concentric with the rotating shaft, and a rotor core that is concentric with the rotor core so as to be in contact with the outer peripheral surface of the rotor core. a cylindrical sleeve mainly made of synthetic resin that covers the outer peripheral surface of the permanent magnet and fixes the permanent magnet so as to resist the centrifugal force of the permanent magnet as it rotates; , in a rotating electric machine comprising a rotor having die-cast end portions at both ends of the rotor core die-cast through a gap between the rotor cores, the outer shape of one end of the die-casting is the inner diameter of the sleeve; 1. A rotating electric machine equipped with a rotor that is smaller in size and characterized in that the outer diameter of the other end of the die cast member is larger than the inner diameter of the sleeve.