JPS608546Y2 - DC motor magnet fixing structure - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a magnet fixing structure for a DC motor using a C-shaped magnet.

Conventionally, ring-shaped and C-shaped magnets are known as field magnets for DC motors. In the case of ring-shaped magnets, they are fixed to the inner surface of the frame using adhesive, and in the case of C-shaped magnets, they are fixed to the inner surface of the frame using adhesive. It is fixed with a frame, or with a positioning protrusion provided on the frame and a magnetic presser spring.

Moreover, methods using adhesives require time for the bonding process and require control over the amount and strength of the adhesive, making them difficult to mass-produce.

On the other hand, the method using a magnetic presser spring has the drawback of requiring a large number of parts and resulting in high costs.

The present invention has been devised in view of the above-mentioned drawbacks of the conventional art, and one embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIGS. 1 and 2, reference numeral 1 denotes a cylindrical frame, which is constructed by butting semicircular frame bodies 2 and 3 together.

Reference numerals 4 and 5 designate end brackets that are fitted and fixed to both end surfaces of the frame 1, and a brush 6 and a terminal 1 are attached to the end bracket 5.

C-shaped field magnets 8 and 9 are fixed to the inner surface of the frame 1, and are installed across the abutting surfaces of the frame bodies 2 and 3.

Reference numeral 10 denotes an armature core attached to a rotating shaft 11, around which an armature winding is wound.

13 is a commutator that is in constant contact with the brush 6, and the rotating shaft 11
installed on.

FIG. 3 shows the configuration of the frame body 2, and 14.1
Reference numeral 4' designates cut-and-raised protruding pieces for elastically supporting the magnets 8 and 9, which are integrally formed on the frame body 2 with different protruding directions.

15.15' is a hole formed in the center of the cut and raised protruding piece 14.14', and 16.16' is a protrusion for regulating the axial position of the magnet 8.9.

Corners 14a and 14a' of the main cut and raised protruding pieces 14 and 14' on the side of the magnet insertion port are bent in a direction away from the inner surface of the frame.

The frame body 3 has the same structure as the frame body 2, and when the cylindrical frame 1 is formed by butting,
The cut and raised protruding pieces formed on the frame body 3 are located at positions opposite to the cut and raised protruding pieces 14 and 14' of the frame body 2.

FIG. 4 shows the structure of the magnets 8 and 9.
a and 9a are formed in an arc shape as shown in FIG.

Note that the corners 8a and 9a may be tapered.

FIG. 6 shows the insertion structure of the magnet 8. First, the frame bodies 2 and 3 are joined to form a cylindrical frame 1, and then the cut-out protruding piece 14 of the frame body 2 and the frame body A magnet 8 is inserted from above between the cut and raised protruding pieces 17' of the body 3.
The protruding pieces 14 and 17' are pressed against their elasticity.

At this time, the corner 8a of the magnet 8 is formed in an arc shape,
Since the corner portion of the cut and raised protruding piece 14, 17' on the side of the magnet insertion port is bent, the bent portion serves as an insertion guide, and the magnet 8 is easily inserted.

Note that the magnet 9 is also fixed in the same manner.

As is clear from the above configuration, according to the present invention, the magnet can be fixed without using an adhesive or a dedicated magnet holding spring, and costs can be reduced.

Press-fitting and fixing the magnet is extremely easy, and there is no risk of damage to the magnet, which is of great practical value.

[Brief explanation of drawings]

Figure 1 is a sectional view of a DC motor according to an embodiment of the present invention, Figure 2 is an exploded perspective view of the frame and bracket of the motor, Figure 3 is a perspective view of the frame element, and Figure 4 is FIG. 5 is a front view of essential parts of the magnet, and FIG. 6 is a cutaway perspective view showing the magnet in its inserted state. 1... Frame, 8, 9... Magnet, 8a, 9a... Corner of magnet, 14.
14'... Cut and raised protruding piece, 4a*14a'...
・・・・・・Corner part of cut and raised protruding piece.

Claims (1)

[Scope of utility model registration request] A pair of cut and raised protruding pieces with different protruding directions are integrally formed at opposing positions of the cylindrical frame, and the corner of the cut and raised protruding pieces on the side of the magnet insertion opening is directed in a direction away from the inner surface of the frame. A magnet fixing structure for a DC motor, in which the corner portions of a C-shaped magnet are bent and press-fitted between opposing protruding pieces to form an arc or a tapered shape.