JPH05137293A - Manufacture of small-sized dc motor with reduction gear - Google Patents

Abstract

PURPOSE:To realize a reduction in noise by preventing a damage, a hit mark to be generated in the case of assembling a spur gear fixed to a motor shaft and a first spur gear of a reduction gear and eliminating noise due to the damage, the mark in a small-sized DC motor with the reduction gear to be used for various type electric devices. CONSTITUTION:A spur gear 4 fixed to a motor shaft 2 and a first spur gear 5 of a reduction gear are assembled from a direction of both tooth crests. Damage, hit mark of a spur gear to be generated in the case of assembling a motor and the gear can be eliminated, and a reduction in noise can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a small DC motor with a reducer used in audio equipment, video equipment (camera integrated videotape recorder, camera, etc.).

[0002]

2. Description of the Related Art In recent years, a small DC motor with a reducer has been required to have improved performance, lower noise, and lower cost as the market expands, and the size and weight of a set have been reduced. Small DC motors are also required to be smaller and lighter.

A conventional method for manufacturing a small DC motor with a reducer will be described below with reference to FIG.

FIG. 4 shows the structure and assembling method of a conventional small DC motor with a reducer. As shown in the figure, the DC motor includes a motor frame 1 and a motor shaft 2.
And a bearing 3 for supporting the motor shaft 2 and a spur gear 4 fixed to the motor shaft 2, and the spur gear 4 meshes with a first spur gear 5 of the speed reducer. The member indicated by the dotted line in the figure is the first spur gear 5 of the reduction gear before being engaged with the spur gear 4 fixed to the motor shaft 2.
Is.

As shown by the arrow, the first spur gear 5 of the speed reducer is assembled from the tooth side surface to the tooth side surface of the spur gear 4 fixed to the motor shaft 2.

Regarding the above-mentioned small DC motor with a reduction gear,
The operation will be described below. First, the rotation speed of the spur gear 4 fixed to the motor shaft 2 is reduced by the first spur gear 5 of the speed reducer, and the motor output is reduced by successive spur gears (not shown).

[0007]

However, in the above manufacturing method, the spur gear 4 fixed to the motor shaft 2 is used.
And the first spur gear 5 of the speed reducer are engaged with each other from the tooth side surface, there is a drawback that both spur gears are easily scratched or dented, and the noise caused by the engagement increases when the spur gears are engaged. Was there.

The present invention solves the above problems and provides a method of manufacturing a small DC motor with a reducer that prevents scratches and dents on the spur gears that occur when the spur gears are meshed with each other. The purpose is to do.

[0009]

In order to achieve the above object, the present invention is to combine the spur gears fixed to the motor shaft and the first spur gear of the speed reducer from the tip direction of the spur gears. It is something to do.

[0010]

According to the present invention, since the spur gear can rotate in the rotational direction even when both tooth tips are engaged with each other by the above-described method, the spur gear can be prevented from being scratched during the engagement.
It is possible to reduce dents.

[0011]

(Embodiment 1) A first embodiment of the present invention will be described below with reference to FIG.

The same components as those described in the conventional example are designated by the same reference numerals and the description thereof will be omitted. As shown in the figure, the difference from the conventional example is that when the spur gear 4 fixed to the motor shaft 2 and the first spur gear 5 of the speed reducer are engaged, the case 6 of the speed reducer is referred to the outer circumference of the bearing 3 as a reference. That is, both spur gears 4 and 5 are combined from the tip direction.

The operation of the small DC motor with a reduction gear manufactured by the above manufacturing method will be described below.

First, when the first spur gear 5 of the speed reducer is meshed with the spur gear 4 fixed to the motor shaft 2, the spur gears 4 and 5 are combined from the tooth tip direction (arrow direction shown in FIG. 1). ) Is performed, and the reference of the pitch between the spur gear 4 fixed to the motor shaft 2 and the first spur gear 5 of the reduction gear is set by the bearing 3 and the reduction gear case 6,
It is possible to assemble and fix the motor unit and the speed reducer unit without causing scratches or dents on both spur gears 4 and 5.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to FIG. As shown in the figure, the outer periphery of the bearing 3 is the burring portion 1 of the motor frame 1.
It is the same as the first embodiment except that it is the outer periphery of a. By providing a reference for the pitch of both spur gears 4 and 5 between the outer periphery of the burring portion 1a and the case 6 of the speed reducer, both spur gears 4 and 5 are not scratched or dented and the motor portion is not generated. The speed reducer can be assembled and fixed.

(Embodiment 3) A third embodiment of the present invention will be described below with reference to FIG.

In the figure, 7 is the case of the speed reducer, and the others are the same as in the first and second embodiments.

By providing pitch references for both the spur gear 4 fixed to the motor shaft 2 and the first spur gear 5 of the speed reducer by the outer circumference of the motor frame 1 and the case 7 of the speed reducer, It is possible to assemble and fix the motor and speed reducer without causing scratches or dents on the gear.

[0019]

As is apparent from the above description of the embodiments, the present invention combines both the spur gear fixed to the motor shaft and the first spur gear of the speed reducer in the directions of the tooth tips of the spur gear. It is possible to achieve low noise without generating scratches or dents on the spur gear. Its practical effect is enormous.

[Brief description of drawings]

FIG. 1 is a partially cutaway side sectional view of a small DC motor with a reducer according to a first embodiment of the present invention.

FIG. 2 is a partially cutaway side sectional view of a small DC motor with a reducer according to a second embodiment of the present invention.

FIG. 3 is a partially cutaway side sectional view of a small DC motor with a reducer according to a third embodiment of the present invention.

FIG. 4 is a side view of a conventional small DC motor with a reducer.

[Explanation of symbols]

 1 motor frame 1a burring part 2 motor shaft 3 bearing 4 spur gear fixed to the motor shaft 5 first spur gear of the reducer

Claims (3)

[Claims] 1. A small direct current motor has a spur gear on a motor shaft, and a first spur gear of the speed reducer is integrally provided with a speed reducer that meshes with the spur gear. When engaging the spur gear No. 1 with the outer periphery of the bearing that supports the motor shaft as a reference, the spur gears are combined from the tip direction of both spur gears, and a small DC motor with a reducer in which the motor unit and the reducer unit are fixed Manufacturing method. 2. The spur gear of the motor shaft and the first of the speed reducer.
When engaging the spur gears of the motor shaft, if the bearing of the motor shaft is press-fitted and fixed to the burring portion of the motor frame, combine the spur gears from the tip direction of both spur gears with the outer periphery of the burring portion of the motor frame as the reference. The method for manufacturing a small direct current motor with a reducer according to claim 1, wherein the and the reducer section are fixed. 3. The spur gear of the motor shaft and the first of the speed reducer.
2. The small DC motor with a reducer according to claim 1, wherein when the spur gears of FIG. Manufacturing method.