JPH03277146A - Assembly of permanent magnet rotor - Google Patents

Abstract

PURPOSE:To prevent windage loss and enable a permanent magnet to be fixed easily by using an insert molding for allowing a plurality of gaps generated in axial direction on a periphery surface of a rotor core to be buried and the permanent magnet to be fixed. CONSTITUTION:A permanent magnet rotor where a permanent magnet 2 is inserted into a rotor core 1 is set into a mold 4. Since a shaft 3 and the mold 4 have a stage, there is gap among an edge surface of the rotor core 1, a press 5, and the mold 4. Resin is injected into the mold 4 from an injection port after sealing by the press 5. Resin is buried into a plurality of gaps and a gap among the edge surface, the press 5, and the mold 4 and the resin is cured to obtain the permanent rotor 1, thus preventing windage loss and obtaining a permanent magnet rotor for fixing the permanent magnet easily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of assembling a permanent magnet rotor of an electric motor such as a DC brushless motor.

[Conventional technology] An example of a conventional method of assembling a permanent magnet rotor is shown in FIG.

As shown in FIG. 4, a permanent magnet 12 is inserted into a rotor core 11 formed by laminating a plurality of silicon steel plates, and circular plates 17 are attached to both end faces of the rotor core 11 using adhesive. It was assembled by doing. A plurality of gaps occurring in the axial direction on the circumferential surface of the rotor core were not filled in and remained as they were.

[Problems to be Solved by the Invention] However, in the conventional assembly method in which permanent magnets are fixed by bonding circular plates to both end faces of the rotor core, the assembly time is reduced because they are fixed with adhesive. However, if the adhesive used is not suitable for the location where the permanent magnet rotor is used, there is a risk of it peeling off, so there is a problem that it is limited to certain types and is expensive.

Furthermore, since the plurality of gaps occurring on the circumferential surface of the rotor core are not filled, there is also the problem that when the permanent magnet rotor rotates, considerable windage loss occurs due to air resistance.

It is an object of the present invention to provide a permanent magnet rotor that eliminates the drawbacks of the prior art, can fill gaps on the circumferential surface to prevent windage damage, and can easily fix permanent magnets to the rotor core. This provides an assembly method.

[Means for Solving the Problems] A method for assembling a permanent magnet rotor according to the present invention includes a rotor core formed by laminating a plurality of silicon steel plates, and a permanent magnet inserted into the rotor core. This permanent magnet rotor is characterized in that insert molding is used to fill in a plurality of gaps occurring in the axial direction on the circumferential surface of the rotor core and to fix the permanent magnets.

[Examples] Examples of the present invention will be described below based on the drawings. 1st
The figure is a perspective view showing the process of assembling a permanent magnet rotor in one embodiment of the present invention. 1 is a rotor core formed by laminating a plurality of silicon steel plates, and 2 is a permanent magnet Sm.
-Co (samarium cobalt) magnet, permanent magnet 2
is inserted in the axial direction into a hole in the rotor core 1 after laminating silicon steel plates. 3 is a shaft, 4 is a mold for insert molding, and 5 is a presser foot. In Fig. 1, a permanent magnet rotor with a permanent magnet 2 inserted into a rotor core 1 is placed in a mold 4.
Set it inside. FIG. 2 shows a sectional view when set. As shown in FIG. 2, since the shaft 3 and the mold 4 are stepped, there is a gap between the end face of the rotor core 1, the presser foot 5, and the mold 4. After sealing the inside of the mold 4 with a presser foot 5, resin is injected from the injection port. Therefore, a plurality of gaps occurring on the circumferential surface of the rotor core and gaps between the end face of the rotor core and the presser foot 5 and mold 4 are filled with resin. Figure 3 shows the permanent magnet rotor after the resin has solidified. Third
As shown in the figure, the solidified resin 6 can prevent windage damage when the permanent magnet rotor rotates, and also allows a structure in which the permanent magnets do not protrude from the rotor core.

Therefore, there is no need for the step of adhering the plate to the end face of the rotor core as in the conventional technology, and it is possible to reduce working time and cost.

In this example, the permanent magnet is Sm-C.

Although a magnet was used, Sm-CaH2 was used as the permanent magnet material.
It goes without saying that the present invention is not limited to stones, and that various magnets such as rare earth-iron-boron magnets, ferrite magnets, etc. can be used in the same manner.

[Effects of the Invention] As described above, according to the present invention, since no plates are used to fix the permanent magnets to the rotor core, no adhesive is required, and assembly time and costs can be reduced. Furthermore, at the same time, the gaps that occur on the circumferential surface of the rotor core are also filled in, eliminating the influence of windage damage.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the process of assembling a permanent magnet rotor in one embodiment of the present invention. FIG. 2 is a sectional view of the permanent magnet rotor shown in FIG. 1 when it is set in a mold. FIG. 3 is a perspective view of the permanent magnet rotor after the resin has solidified. FIG. 4 is a perspective view showing the process of a conventional permanent magnet rotor assembly method. 1.11... Rotor core 2.12... Permanent magnet 3.13... Shaft 4... Gold Type 5...
・・・・・・・・・Presser foot 6・・・・・・・・・・・・・
・Resin 17・・・・・・・・・Plate or higher

Claims (1)

[Claims] In a permanent magnet rotor comprising a rotor core formed by laminating a plurality of silicon steel plates and a permanent magnet inserted into the rotor core, a permanent magnet is formed on the circumferential surface of the rotor core in the axial direction. 1. A method for assembling a permanent magnet rotor, characterized in that insert molding is used to fill in a plurality of gaps and fix the permanent magnets.