JPS6318949A - Vibration preventing device for small-sized motor - Google Patents

Abstract

PURPOSE:To hold the stable rotation of a small-sized motor by pressing the spherical part at an end of a motor shaft by an elastic member to suppress the movement of the shaft to a minimum limit. CONSTITUTION:An elastic member 8 made of a leaf spring presses the spherical part of the end of a motor shaft 3. Thus, forces are applied to the shaft 3 in the directions of thrust load F1 and side load F2. A motor shaft 3 which tends to irregularly move and rotate is suppressed to the minimum limit by the forces F1, F2 within a clearance of a metal bearing 4 and the shaft 3.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a small motor used in a VTR or audio equipment, in which the rotating shaft is driven by a gear during light side pressure.
This invention relates to a vibration prevention device for a small motor that prevents clearance vibration and noise generated between metal bearings.

BACKGROUND OF THE INVENTION In recent years, as sets of VTRs and the like have become lighter, thinner, and smaller, gear drive systems have been increasingly adopted as vibration prevention devices for small motors, and vibration prevention is becoming more important.

An example of the vibration prevention device for the above-mentioned conventional small motor will be described below with reference to the drawings.

FIGS. 5 and 6 show examples of vibration countermeasures for a conventional small motor.

In FIG. 5, 1 is a motor frame, and a magnet 2 is fixed to the inner surface of the motor frame. 3 is the motor shaft,
It is supported by a metal bearing 4 provided on the motor frame 1.

5 is an armature assembly; 6 is a spring that applies side pressure to the shaft 3; one end thereof is fixed to the motor frame 1;

The operation of the vibration prevention device for a small motor configured as described above will be explained below.

First, if there is no spring 6 for holding down the shaft, the motor shaft 3 will move around within the clearance between the motor shaft 3 and the metal hair ring 4, producing a sound hitting the inner surface of the metal bearing and a vibration component, which will cause resonance when the set is mounted. The sound becomes even louder at the interval 7■.

Therefore, by applying a shaft presser spring 6 to the motor shaft 3 with a certain spring pressure, the clearance between the metal bearing 4 and the motor shaft 3 can be made zero, and the movement of the motor shaft 3 can be suppressed by changing external loads such as gears (-2). Minimize to reduce noise and vibration.

FIG. 6 shows another conventional example, in which a magnet 7 is used in place of the spring 6.

The operation of the vibration prevention device for a small motor configured as described above will be explained below.

If magnet 7 is not added, motor shaft 3
The movement of the metal bearing 4 is the same as that of the conventional example shown in FIG. Therefore, by bringing the magnet 7 close to the shaft 3 and attracting the shaft 3 with magnetic force,
The movement of shaft 3 was kept to a minimum to reduce noise and vibration.

Problems to be Solved by the Invention However, with the above configuration, the configuration shown in FIG. And again,
By applying the shaft presser spring 6 to the outer periphery of the motor shaft, the sliding length becomes longer and the shaft presser spring 6 and the motor shaft 3 suffer from increased wear.

Further, the configuration shown in FIG. 6 is disadvantageous in that the dimensions for mounting the gear are small, as in the case of FIG. 5. Moreover, it also had the problem of high cost.

In view of the above-mentioned problems, the present invention aims to reduce the noise and vibration of the motor shaft and metal hair ring in order to reduce the size and weight of the set or gear unit, prevent wear of the shaft or spring, and reduce costs. Means for Solving the Problems of Providing a Vibration Prevention Device In order to solve the above problems, the vibration prevention device for a small motor of the present invention includes a spring material or a spring material in the spherical part at the tip of the motor shaft. The elastic member is made of a certain resin or the like and is configured to apply forces in two directions, a thrust load and a lateral pressure load, to the motor shaft.

Effect: According to the above configuration, the elastic member presses down the spherical portion at the tip of the motor shaft, so that movement of the motor shaft can be minimized and stable rotation can be maintained.

Embodiment Hereinafter, one embodiment of the present invention will be described with reference to the drawings regarding a vibration prevention device for a small motor.

FIG. 1 shows a configuration diagram of a first embodiment of the present invention, in which 1 is a motor frame, 2 is a magnet, 3 is a shaft, 4 is a metal bearing, and 5 is an armature assembly.
These are similar to the conventional configuration. Reference numeral 8 denotes an elastic member made of a spring plate that contacts the spherical portion at the tip of the motor shaft and applies a thrust load F1 and a lateral pressure load F2 to the motor shaft 3.

FIG. 2 shows an embodiment of the mounted gear unit section, where 9 is a gear unit chassis, 10 is a pinion gear attached to the motor shaft 3, and 11 is a gear unit.

In the above configuration, the elastic member 8 presses down the spherical part at the tip of the motor shaft, and forces are applied to the motor shaft 3 in the directions of Fl (thrust load) and F2 (lateral pressure load), and the metal bearing 4 and motor Within the clearance of the shaft 3, the motor shaft 3, which tends to move irregularly, is kept to a minimum by Fl and F2, and stable rotation is maintained.

As described above, according to this embodiment, the elastic member 8 presses the spherical portion at the tip of the motor shaft, creating a stable motor rotation state in a certain direction and reducing noise and vibration.

A second embodiment of the present invention will be described below with reference to the drawings.

FIG. 3(a) is a block diagram of a vibration prevention device for a small motor showing a second embodiment of the present invention.

In the figure, reference numeral 12 denotes an elastic member integrally formed with the gear unit chassis 9 made of synthetic resin.
Loads are applied to the motor shaft 3 in two directions.

Regarding operation 3, the configuration is the same as that shown in FIG. 1, and the movement of the motor shaft 3 is made stable and vibrations are reduced.

As described above, by providing the elastic member 12 that presses the shaft in a part of the resin chassis 9, the number of parts can be reduced compared to the first embodiment, which is effective in reducing costs.

In the first embodiment, the elastic member 8 for holding down the shaft is made of a spring material, but it may be made of a resin material. Further, in the second embodiment, the elastic member 12 is formed by integral resin molding, but even if the chassis 9 is made of metal, the chassis 9
It is possible to obtain an elastic member integral with.

Further, even if an elastic member 13 made of a chevron-shaped spring as shown in FIG. 3(b) is attached, the same effect as described above can be obtained.

Figure 4 shows 1, when the above-mentioned elastic member is attached (Figure 4a)
) and vibration analysis data when there is no elastic member (Fig. 4b).

Effects of the Invention As described above, the present invention reduces the clearance noise and vibration between the motor shaft and the hair ring by bringing into contact the spherical part at the tip of the motor shaft with an elastic member that simultaneously applies a thrust load and a lateral pressure load. be able to.

[Brief explanation of the drawing]

Fig. 1 is a half-sectional view of a vibration prevention device for a small motor according to the first embodiment of the present invention, Fig. 2 is a sectional view showing an example of mounting on the gear unit section of Fig. 1, and Fig. 3 is a spring attachment. Figures 5 and 6 are half-sectional views of a conventional vibration prevention device for a small motor. 3...Motor shaft, 8,12.13...
...Elastic member. Name of agent: Patent attorney Toshio Nakao and one other person Figure 3 Figure 4 HA' Saizu I's general information 1 ξ - 7 Butorikika Prayer - 7〈Details
Growing JIFO motor mount η outside F hitch” 9 Fig. 5

Claims (1)

[Claims] A vibration prevention device for a small motor, comprising an elastic member that applies a load in a thrust direction and a load in a lateral pressure direction to the motor shaft, which contacts the spherical tip of a motor shaft to which a gear is attached.