JPS5836584B2 - Manufacturing method of coreless motor rotor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a rotor for a coreless motor, and more particularly, to a method for manufacturing a rotor for a thin coreless motor.

Coreless motor, especially for small tape recorders etc. L
- In addition to always rotating at a constant speed, coreless motors must rotate evenly, smoothly, and stably.

In order to do this, the rotor must be dynamically balanced with respect to the rotation axis and must swing L.

However, in conventional coreless motors of this type,
The rotor coils are manually placed appropriately around the motor's rotation axis using a jig, and then fixed with a filler to form the rotor.
Therefore, it was extremely difficult to obtain a dynamic balance of the rotor.

Next, before explaining the present invention, the above-mentioned conventional example will be explained with reference to FIGS. 1 to 3 in the case where the number of coils is three.

The coreless motor 1 is fitted into a housing T formed by a cylinder 6 and upper and lower end plates 5a and 5b, which also serve as yokes and which are fixed to the upper and lower edges of the cylinder 6, at the center of the upper and lower end plates 5a and 5b. The rotary shaft 2 is configured to rotatably fit into the bearings 8a and 8b.

The rotating shaft 2 includes a commutator 3 and coils 15a, 15b,
15c (see FIG. 5) is integrally connected to the rotor 4, the lower end of the shaft 2 is received by a receiving plate 9 fixed below the bearing 8b, and the upward thrust is , the upper end surface of the commutator 3 and the lower end surface of the bearing 8a are connected to each other by a spacer.
13, respectively.

Further, a magnet 10 that is disposed opposite to the upper surface of the rotor 4 is fixed to the housing 7, and a pair of brushes 11a and 11b that contact the commutator 3 are also fixed to the housing 7, respectively.

The rotor 4 of the conventional coreless motor configured as described above was manufactured as follows.

That is, first, the rotating shaft 2 and the commutator 3 are bonded together using a bonding agent 12 to create a bonded body 17 as shown in FIG.

A flange portion 17a is formed at the lower end of this combined body 17.

On the other hand, the casting jig 14 for joining the above-mentioned combined body 17 and the coils 15a to 15c (see FIG. 5) by casting is as follows:
As shown in FIG. 3, a recess 14a having the same shape as the rotor 4 is provided on the upper surface of the recess 14a, and a recess 14a having the same shape as the rotor 4 is provided at the center of the bottom surface thereof. hole 1
4b is provided.

After fitting the flange 17a of the combined body 17 into the fitting hole 14b of the casting jig 14, the
After the rotor coils 15a, -15b, and 15C made of conductive wires or conductive wires as shown by , B are connected to the commutator 3 at both ends by soldering or the like, the fifth
Arranged as shown in the figure.

After the rotating shaft 2, commutator 3, and rotor coils 15a, 15b, and 15c are arranged in the casting jig 14 in this way,
Inject an epoxy resin type potting agent 16 to fix the whole,
After fixing, the jig 14 is removed, and the rotor 4 (see FIG. 1) is integrally formed with the rotating shaft 2 and commutator 3.

In this case, in order for the rotor 4 to be dynamically balanced with respect to the rotating shaft 2, the rotor coils 15a, 15b, and 15c must be arranged at equal intervals in the jig 14. However, since this arrangement is done by hand, the rotor coil works on the casting mold, and its positioning is extremely difficult, requires great care, and takes a lot of time. Even so, the dynamic balance and magnetic balance were disturbed, and it was not sufficient, and this unbalance due to manufacturing caused the motor to rotate 10 times unsmoothly.

On the other hand, it is desirable that coreless motors used in small tape recorders and the like be made as thin as possible because tape recorders are made thinner, and this is also the reason why coreless rotor coils are used.

In view of the above points, an object of the present invention is to make a coil stand made of synthetic resin to correctly determine the position of the rotor coil, place the rotor coil on the coil stand, and cast it together with a commutator. Then, the present invention provides a method for manufacturing a thin rotor by cutting the bottom of the coil stand.

Since the rotor obtained in this way has a balanced coil, it is dynamically balanced, and the thickness of the rotor can be minimized, and other Unlike coil stands made of thin plates, there is no need to worry about deformation, making it extremely practical.

Hereinafter, the present invention will be explained in detail based on an illustrated embodiment.

FIG. 6 is a sectional view of a coreless motor 18 in which the rotor of the present invention is used.
Since it is similar to the one shown in the figure, the same parts (・
The same reference numerals are given to the same reference numerals, and the explanation thereof will be omitted.

In the manufacturing process of the rotor 20 according to the present invention, a coil stand 21 as shown in FIG. 7 is used.

The coil stand 21 is formed into a disk shape having an outer diameter approximately the same as the outer shape of the rotor by integrally molding the combined body 17, in which the rotating shaft 2 and the commutator 3 are bonded by a binder 12, using a synthetic resin or the like. is formed.

On this coil stand 210 base 21a are rotor coils 24a, 24b, 24c (eighth
Refer to the figure. This example is for a case where the number of coils is three.

) Coil guides 22a, 22b, 22.C for coil positioning are formed to fit into the inner diameter holes of L.

The height of the coil guides 22a, 22b, 22C is approximately equal to the thickness of the coils 24a, 24b, 24C, and
By fitting the inner diameter holes of each coil into this, each coil is formed at a position where it is arranged in a well-balanced manner on the coil stand 21.

The ko formed in this way. As shown in FIG. 8, the coil stand 21 is a casting jig that has the same shape as the coil stand 210 base 21a and has a depth equal to the height of the coil guides 22a to 22c and the thickness of the coil stand 21. 23 is fitted into the recess 23a.

Next, for the commutator 3 of the coil stand 21, each coil 24
After connecting the tips of the lead wires a to 24c by soldering or the like, the inner diameter holes of each rotor coil 24a to 24c are fitted into the coil guides 22a, 22b, and 22c, respectively, and each coil is placed on the coil stand 21. are arranged as shown in FIG.

In this state, if an epoxy resin pouring agent is injected into the recess 23a of the casting mold jig 23 and is taken out from the recess 23a of the jig 23 after waiting for it to solidify, as shown in FIG. A rotor 25 of the present invention is obtained as shown in FIG.

The bottom of this rotor 25 is connected to the base 21a of the coil stand 21.
A rotor 20 according to the present invention as shown in FIG. 10 is obtained by cutting it off with a lathe or the like until only a small amount remains.

The rotor 20 obtained in this way has a coil stand 21
Each coil is placed in a correctly balanced position, and each coil is fixed by casting with a synthetic resin pouring agent, making the whole strong and making it difficult to mold other thin sheets. There is no problem of warping or deformation like with a coil stand due to processing.

Furthermore, the increase in the thickness of the rotor due to the base plate 21a of the coil stand 21 is negligible, and the intended purpose is successfully achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional coreless motor equipped with a rotor, FIG. 2 is a perspective view showing a combination of the rotating shaft and commutator in FIG. A perspective view of the casting jig used for manufacturing the rotor in Figure 1, Figure 4A
, B are perspective views showing an example of the rotor coil, respectively.
The figure is a plan view showing the state in which the coils are arranged in the casting jig shown in Fig. 3 above, Fig. 6 is a sectional view of a coreless motor to which the rotor according to the present invention is applied, and Fig. 7 is a plan view showing the state in which the coil is arranged in the casting jig shown in Fig. 3 above. A perspective view of the coil stand used in the rotor, FIG.
FIG. 7 is a plan view showing the state in which the rotor coil is placed on the coil stand, FIG. 9 is a side view of the rotor obtained by casting in the state shown in FIG. 8, and FIG. 9th
Figure 3 is a side view of a rotor according to the invention obtained by cutting the bottom of the rotor shown; 18...Coreless motor 20...Rotor 21
...Coil stand.

Claims (1)

[Claims] 1. Form a coil stand for coil positioning that is integrated with the commutator by molding synthetic resin, place the rotor coil on this coil stand, and then integrate the commutator, rotor coil, and coil stand by casting. A method for manufacturing a rotor for a coreless motor, characterized in that after casting, the bottom of the coil stand is cut to make the rotor thinner.