JPS5915260B2 - Coreless motor rotor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a rotor for a coreless motor.

Coreless motors, especially coreless motors used in small tape recorders, etc., must not only always rotate at a constant speed, but must also rotate smoothly, stably, and evenly.

To do this, the rotor must be dynamically balanced with respect to the axis of rotation.

However, in conventional coreless motors of this type,
Using a jig around the rotation axis of the motor,
Since the rotor was formed by manually arranging the coils and solidifying them with a casting agent, it was extremely difficult to obtain the 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 for a 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. Bearing 8a.

The rotating shaft 2 is rotatably fitted into the rotating shaft 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 spacer 1 connects the upper end surface of the commutator 3 and the lower end surface of the bearing 8a.
3.

Further, the magnet 10 provided opposite to the upper surface of the rotor 4 is a pair of brushes 11a fixed to the housing 7 and in contact with the commutator 3.

11b are also fixed to the housing 7, respectively.

The rotor 4 of the conventional coreless motor configured as described above was manufactured in the following manner.

That is, first, on the rotating shaft 2, as shown in FIG.

The commutators 3 are concentrically insulated and bonded together by a bonding agent 12.

The commutator 3 integrally connected to the rotating shaft 2 in this way is connected to the third
It is fitted into a through hole 14a drilled in the center of the bottom of a saucer-shaped casting mold jig 14 shown in the figure, and inside this jig 14,
After the coils 15a, 15b, 15c made of conductive wires or conductive bands as shown in FIG. arranged as shown.

In this way, the rotating shaft 2, commutator 3, and coils 15a, 15b, and 15c were placed in the casting jig 14, and an epoxy resin casting agent 16 was injected to fix the entire structure. After that, when the jig 14 is removed, 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 coils 15a, 15b, 15c must be arranged at equal intervals within the jig 14. Since this arrangement is done by hand, the coil moves on the casting jig, and its positioning is extremely difficult, requires great care, and takes a lot of time to achieve dynamic balance. This caused the magnetic balance to go out of order, making it unsatisfactory, and this manufacturing imbalance caused the motor to rotate 10 times unsmoothly.

Therefore, in order to eliminate such manufacturing defects of the rotor, the present applicant has formed a coil stand for coil positioning in order to correctly determine the position of the rotor coil, integrally with the commutator. We have previously proposed a means of obtaining a rotor that is properly sidodynamically balanced.

However, even in a rotor in which the coils are arranged in this manner, there are still cases where precise dynamic balance cannot be achieved due to irregularities in the coils.

In this case, since the arrangement of the coils is fixed by the coil stand, it is impossible to change and adjust this arrangement.

Therefore, even in such a case, some kind of special measures are required in order to obtain precise dynamic balance.

In view of the above points, an object of the present invention is to skillfully utilize the portion of the coil stand other than the rotor coil arrangement portion,
Provided is a rotor for a coreless motor in which a storage chamber for storing balance weight members is formed in the coil stand, and appropriate balance weight members are stored in this storage chamber, making it possible to extremely easily achieve precise dynamic balance. It's in Sur.

The present invention will be explained below based on an embodiment shown in FIGS. 6 to 9.

Although this embodiment deals with a case where the number of coils is three, it goes without saying that the present invention can be applied regardless of the number of coils.

FIG. 6 is a sectional view of a coreless motor 21 provided with a rotor 24 according to the present invention.

In the figure, other members except the rotor 24 and the coil stand 25 are configured exactly the same as those of the coreless motor 1 in the conventional example shown in FIG. , and the explanation thereof will be omitted.

Coils 29a, 29b, 29c (9th
As shown in FIGS. 7 and 8, the coil stand 25 for arranging the coil stand 25 (see figure) has an outer diameter that is integral with the commutator 3.
It is a disk-shaped object approximately equal to 4, and on its upper surface,
Coil guides 26a to 26c fit into the inner diameter holes of the coils 29a to 29c to arrange each coil in a well-balanced position, and boundary walls 27a to 27a to correctly position the outer periphery of each coil. 27c is formed to protrude.

Coil guide 2 formed to protrude from the coil stand 25
6a to 26c and boundary walls 27a to 27c are coil stands 25
It is formed by softening (for example, vinyl chloride) 1 and vacuum forming it.

Therefore, as shown in the sectional view of FIG. 8 and the rear view of FIG. 9, the coil guides 26a to 26c and the boundary wall 27
On the back side of the protruding parts of a to 27c, that is, on the back side,
Recesses 26a' to 26a', 27a' of approximately the same shape
~27c' is formed.

In the present invention, the recesses 26a' to 26c', 27a
' ~ 27 c''E It is cleverly used as a storage chamber for storing a balance weight member 30 for achieving precise dynamic balance of the rotor 24.

The balance weight member 30 is, for example, a small lead ball or the like, and is inserted into the storage chambers 26a' to 26c' and 27a'.
- 27c', an appropriate number of them are fixed and stored with an adhesive or the like.

By forming the coil stand 25 in this manner, the dynamic balance can be maintained in advance and the coils 29a to 29c
By further using a balance weight member, the balance of the rotor 24 provided with the rotor 24 can be precisely and easily adjusted, and the desired purpose can be achieved.

Furthermore, the manufacturing process is extremely simple, and the number of man-hours does not particularly increase.

Next, other embodiments in which the present invention is applied to different coil stands formed integrally with the commutator of a motor will be described.
This will be explained based on FIG.

A coreless motor to which this rotor is applied has the same structure as that shown in FIG. 6, except for the coil stand, so a description thereof will be omitted here.

Also, this embodiment is a case in which there are three coils.

FIG. 10 is a perspective view showing another embodiment of the coil stand.

As shown in the figure, the coil stand 35 is a disc-shaped member having a shape approximately equal to that of the rotor, and the upper part and the outer part of the peripheral part are open near the periphery where it is divided into three parts. , three coil chambers 36a to 36c having substantially the same shape as the coils 39a to 39c (see FIG. 12) are provided.

Grooves 37a to 37c are provided in the inner peripheral walls of the coil chambers 36a to 36c near the commutator 3, respectively.
8 to 37c include pressing members 38a to 3 made of rubber material or the like.
8c (see FIG. 12) are inserted, respectively, and this pressing member 3
Due to the interposition of coils 8a to 38c, coils 398 to 39 are pressed and fixed to the outer peripheral edges of coil chambers 36a to 36C, respectively.

This coil stand 35 is made of, for example, a softened vinyl chloride sheet and molded using a vacuum forming machine, as in the case of the embodiment shown in FIG. It is formed as shown in the sectional view in the figure and the back view in FIG.

That is, the parts on the back side of the parts 358 to 35c excluding the coil chambers 36a to 36c shown in FIG. 10, that is, the parts on the back side become recessed parts when viewed from the back side, as shown in FIG. .

The shape of this concave portion corresponds to the portion protruding from the upper surface, and the base portions of the three cavities 358' to 358' are connected to each other.
5c' is formed.

In the present invention, the above-mentioned empty rooms 358' to 35C' are used as balance weight member storage chambers, and these empty rooms 35a' to 350
As in the previous embodiment (see FIG. 9), an appropriate number of balance weight members 40 made of small lead balls or the like are housed at appropriate positions within ', and these are fixed with adhesive. , the final dynamic balance of the rotor was achieved precisely.

The effects in this case are the same as in the previous embodiment.

As described above, according to the present invention, it is possible to provide a rotor for a coreless motor in which dynamic balance of the rotor can be easily achieved.

In particular, in the present invention, the recess on the back side of the coil positioning projection is used as a balance weight member storage chamber, and the balance weight member is stored in this storage chamber, so space can be used effectively and the motor can be made smaller. It is.

Although the above description has been made regarding a cast rotor, the present invention is similarly applicable to a rotor injection molded from synthetic resin, and the structure and effects thereof are equally applicable, and the present invention includes the rotor. Of course.

[Brief explanation of drawings]

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 is a perspective view showing an example of the coil, FIG. 5 is a plan view showing the state in which the coil is placed in the casting jig shown in FIG. 3 above, and FIG. 6 is a perspective view showing an example of the coil. A sectional view of the coreless motor, FIG. 7 is a perspective view showing an example of a coil stand used in the present invention, FIG. 8 is a sectional view taken along the line X-X in FIG. 7, and FIG. FIG. 10 is a perspective view showing another example of the coil stand used in the present invention, FIG. 11 is a sectional view taken along the Y-Y line in FIG. 10, and FIG. FIG. 12 is a back view of FIG. 10 above. 21... Coreless motor, 3... Commutator, 24.
... Rotor, 25, 35 ... Coil stand, 26a'-
26♂. 278'-27c', 35a'-35c'...Storage chamber, 30°40...Balance weight member.

Claims (1)

[Claims] 1. A rotor for a coreless motor, which is integrally formed with a commutator and includes a disc-shaped coil stand made of a synthetic resin material, and a plurality of rotor coil positioning protrusions provided on the coil stand and having four parts on the back surface. A rotor for a coreless motor, characterized in that the concave portion on the back surface of the protrusion is a balance weight member storage chamber, and a balance weight member for dynamically balancing the rotor is stored in the storage chamber.