JP2992482B2 - Flat coreless geared motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a flat coreless geared motor for driving a pickup used in a portable mini disk device or the like.

[0002]

2. Description of the Related Art Conventionally, as a geared motor for driving a pickup used in a portable mini disk device or the like, a worm gear or the like is attached to an output shaft of a small cylindrical DC motor, and an increased output is extracted through a flat gear. There is something that I did. However, with such a configuration, it is difficult to reduce the thickness, and there is a limit in terms of power in making a small cylindrical DC motor thinner, and it is unlikely to be realized.

[0003]

Therefore, it is conceivable to adopt a so-called flat geared motor in which the motor main body is of a flat type. That is, as shown in FIG. 2, there is a motor in which a pinion gear P is attached to an output shaft of a flat coreless motor M having a thickness of about 4 mm. Usually, such a pinion gear is made of polyacetal resin to reduce mechanical noise, and has to be thinned to about 0 or 5 mm in order to make the thickness flat, which causes a problem that the pull-out strength becomes weak. is there.

An object of the present invention is to provide an extremely thin flat coreless geared motor having no draw-out strength problem without using a special member such as a reinforcing plate or an adhesive. Even with a rectifier having a deformed opening angle such as a 90-degree opening angle without using a member, an appropriate sliding contact opening angle and sliding contact pressure can be obtained.

[0005]

Means for Solving the Problems The above-mentioned problems can be solved by using the dead space of the flat axial gap motor to increase the press-fit length of the pinion gear mounting portion.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As one embodiment of the present invention, in a flat geared motor in which a gear is arranged on an output shaft, a part of a housing around the output shaft is internally formed in order to increase the press-fitting strength. It is sufficient to provide a concave part which is recessed in the direction, and a part of the gear enters into this concave part.

As another embodiment, it is preferable that a brush base is placed on a step formed inside the recess and an axial sliding contact type brush is implanted.

If the recess is provided as described above, the press-fit length of the gear can be increased, so that the pull-out strength can be increased.

If the brush base is placed on the step formed inside the recess and the axial sliding contact type brush is implanted, the deformation opening angle other than the normal 180 degree sliding contact opening angle is improved. For example, in the case of a sliding contact opening angle of 90 degrees, an appropriate sliding contact opening angle and sliding contact pressure can be obtained.

[0010]

FIG. 1 is a sectional view of a main part of an embodiment of the present invention. In the figure, a housing H comprises a shallow dish-shaped case 1 and an end bracket 2 attached to an opening edge of the case 1.
An output shaft S is rotatably mounted via a and 2a. A flat rotor 3 is integrated with the output shaft S together with a flat plate commutator 4 composed of a printed wiring board arranged on one surface. A ring-shaped magnet 5 is mounted on the inside of the end bracket 2 so as to face the rotor 3 through a gap, and the end bracket portion inside the ring-shaped magnet 5 is cut into the thickness of the magnet 5. It rises to form a step 2b. Therefore, when viewed from the outside, the recess 6 including the bearing 2a is formed. A pinion gear 7 having a thickened portion of the recess 6 is press-fitted into the output shaft S protruding from the recess 6.
By doing so, the press-fitting strength of the pinion gear 7 can be increased, so that there is no need to integrate a reinforcing metal plate or the like.

In the drawing, reference numeral 8 denotes a base end implanted on the step portion 2b via a brush base 9 made of a flexible substrate.
It is a pair of axial sliding contact type flat brushes that are in sliding contact with the flat plate commutator 4 at an opening angle of 90 degrees. This way,
Even if the magnet has a relatively large thickness, an appropriate sliding contact opening angle and sliding contact pressure can be obtained.

[0012]

According to the present invention, the strength of press-fitting of the pinion gear 7 can be increased by a structure that skillfully incorporates the structure of the flat coreless motor in the axial direction as described above. It is possible to provide an extremely thin flat coreless geared motor that does not have a problem of pull-out strength without using special members such as a rectifying device having a deformed opening angle such as a 90-degree opening angle. The contact opening angle and the sliding contact pressure can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an embodiment of a flat coreless geared motor according to the present invention.

FIG. 2 is a side view of the conventional motor.

[Explanation of symbols]

 H housing 1 case 2 end bracket 3 flat rotor 4 flat commutator 5 magnet 6 recess 7 pinion gear 8 flat brush

Claims (2)

(57) [Claims] In a flat geared motor in which a gear is arranged on an output shaft, in order to increase the press-fit strength of the gear , a c- shaft is provided.
Magnet the inside of the ring magnet inside the ring magnet.
A flat coreless geared motor in which a concave portion is formed so as to bite into the thickness of the gear, and the concave portion of the gear is formed thick to enter the concave portion. 2. The flat coreless geared motor according to claim 1, wherein a brush base is mounted on a step formed inside the recess and an axial sliding contact type brush is implanted.