JPH0712122A - Motor - Google Patents

Abstract

PURPOSE:To facilitate pre-load control of a bearing extremely and facilitate setting of an air gap so as to reduce its cost. CONSTITUTION:The inner ring 60 of a bearing 72 is arranged on a rotary shaft 20 and an energizing means 70 is provided between a rotor 32 and the inner ring 60 of the bearing 72 in a motor provided with the rotary shaft 20, the rotor 32 fixed to the rotary shaft 20, and the bearing 72 arranged in relation to the rotary shaft 20 and a stator 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optimum motor for use as a motor for rotating a VTR drum.

[0002]

2. Description of the Related Art A conventional VTR drum motor is shown in FIG.
The structure is as shown in. The motor in FIG. 8 is a so-called plane-opposed motor, and the rotor case 2 is fixed to the rotating shaft 1. Its rotor case 2
The magnet 3 is fixed to the. The rotor case 2 and the magnet 3 form a rotor.

A ring 5 is fixed to the rotor case 2 via screws 4. This ring 5 is further fixed to the shaft 1 by means of screws 6. The stator 7 arranged to face the rotor case 2 is fixed to the lower drum (fixed drum 8) of the rotary drum.

A bearing 9 is arranged between the lower drum 8 and the shaft 1. The inner ring 9a of this bearing is arranged with respect to the shaft 1, and the outer ring 9b is fixed to the lower drum 8. A ball 9c is arranged between the inner ring 9a and the outer ring 9b.

The ring 5 is for applying a preload to the inner ring 9a of the ball bearing 9. The reason why the preload is applied in this way is to prevent looseness of the bearing 9. To attach this ring and apply preload to the ball bearing 9, insert the shaft 1 into the ring 5 before attaching the rotor case 2 and apply preload with the ring 5 to attach the ring 5 to the shaft 1. The screw 6 was screwed to an appropriate position.

[0006]

Since the fixed position of the ring 5 tends to vary in order to carry out such a bearing preloading method, the air gap G between the magnet 3 of the rotor and the surface of the stator 7 is adjusted. In this case, a spacer (not shown) was required, and in order to obtain the setting accuracy of the air gap G, it was necessary to prepare spacers having various thicknesses.

From the above, the conventional bearing preloading method has a drawback that the work is difficult, and moreover, a lot of man-hours are required for adjusting the gap, which is very costly.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to remarkably easily control the preload of the bearing, to easily set the air gap, and to reduce the cost. Is intended to provide.

[0009]

In the present invention, the above object is to provide a rotary shaft, a rotor fixed to the rotary shaft, and
In a motor provided with a bearing provided in association with this rotating shaft and a stator, an inner ring of the bearing is arranged on the rotating shaft, and between the rotor and the inner ring of the bearing,
Achieved by a motor with biasing means.

In the present invention, preferably, the biasing means is a coil spring. Further, in the present invention, preferably, a fixed drum of a rotary drum is integrally fixed to the stator. Further, in the present invention, preferably, the biasing means is arranged along the outer peripheral portion of the rotary shaft.

[0011]

According to the above construction, the urging means applies an urging force to the inner ring of the bearing to apply a pressure to the bearing. At this time, the air gap between the rotor and the stator can be set.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the examples described below are suitable specific examples of the present invention, and therefore, various technically preferable limitations are given, but the scope of the present invention particularly limits the present invention in the following description. Unless otherwise stated, the present invention is not limited to these modes.

FIG. 1 shows a rotary drum for a VTR to which a preferred embodiment of the motor of the present invention is applied.

First, the rotary drum for a VTR will be described. The rotary drum 10 for a VTR has an upper drum 12 and a lower drum 14. A rotary transformer (not shown) is arranged on the lower surface 12a of the upper drum and the upper surface 14a of the lower drum.
Signals are exchanged between the four in a non-contact manner.

The upper drum 12 is a rotary drum which the VTR tape touches. The upper drum 12 is fixed to the flange 22 with screws. The inner diameter portion of the flange 22 is fixed to the rotary shaft 20.

On the other hand, the lower drum 14 is a fixed drum with respect to the upper drum 12. A ring-shaped stator 34 made of a magnetic material such as iron is fixed to the concave portion of the lower surface of the lower drum 14.

Next, the motor 30 arranged below the lower drum 14 will be described. The motor 30 is a plane facing motor. The rotor 32 of the motor 30 is fixed to the shaft 20 via the rotor boss 40.
The stator 34 facing the rotor 32 is fixed to the lower drum 14 as described above.

The rotor boss 40 of the rotor 32 connects or fixes the shaft 20 and the rotor case 42 made of a magnetic material such as iron. A ring-shaped magnet 44 is fixed to the rotor case 42. The magnet 44 is magnetized with S poles and N poles alternately in multiple poles.

The magnet 44 is arranged so as to face the stator 34, and the air gap formed between the magnet 44 and the stator 34 is indicated by G.

Next, the two sets of bearings 50 and 72 will be described. Two sets of bearings or bearings 50 and 72 are arranged in association with the stator 34 and the lower drum 14, the rotary shaft 20, and the flange 22. The bearing 50 includes an inner ring 52, an outer ring 54, and a ball 56. The inner ring 52 is arranged with respect to the shaft 20. The outer ring 54 is fixed to the lower drum 14.

On the other hand, the bearing 72 includes an inner ring 60, an outer ring 62 and a ball 64. The inner ring 60 is arranged on the shaft 20. The outer ring 62 is fixed to the lower drum 14. Inner ring 52 of bearing 50 and bearing 7
The second inner ring 60 is not fixed to the outer peripheral portion of the rotating shaft 20 and is movable with respect to the rotating shaft 20.
Further, the rotary shaft 20 includes the flange 22 and the rotor boss 40.
Has been press-fitted against. Moreover, the outer ring 54 of the bearing 50 and the outer ring 62 of the bearing 72 are
Has been pressed into.

Further, the rotor boss 40 and the bearing 7
A coil spring 70 as a biasing means is provided between the two inner rings 60.
Are arranged. That is, the coil spring 70 is arranged so as to pass through the outer circumference of the rotary shaft 20.

The coil spring 70 directly biases the inner ring 60 of the bearing 72 upward in the drawing along the axial direction with a preset biasing force.

Next, please refer to FIG. 2 to FIG. First,
The outer ring 62 of the bearing 72 is fixed to the lower drum 14 of FIG. 2 as shown in FIG. That is, the bearing 72 is pressed into the lower drum 14.

Next, as shown in FIG. 4, the rotary shaft 1 is inserted downward into the inner ring 60 of the bearing 72 as shown by the arrow. Then, the coil spring 70 is inserted into the rotating shaft 1 from below.

Next, the value of the air gap G is adjusted at the same time as the rotor boss 40 of the rotor 32 is press-fitted into a predetermined position of the rotary shaft 20. At this time, as shown in FIG.
The coil spring 70 directly moves the bearing 7 in the direction shown by the arrow.
Preload the second inner ring 60. Inner ring 6 of this bearing 72
The preload for 0 can be controlled to an appropriate value by the spring constant of the coil spring 70. Therefore, the value of the air gap G is automatically set by the spring constant of the coil spring 70.

The inner ring 52 of the other bearing 50 in FIG. 1 is preloaded downward by the inner end 22a of the flange 22 along the axial direction. In this way, the bearings 72, 50 are connected to the coil spring 70 and the flange 22.
Since it is preloaded by, the bearing preload management becomes easy.

Next, please refer to FIG. 6 and FIG. FIG. 6 shows another embodiment of the motor of the present invention. In the embodiment shown in FIG. 6, the rotor boss is not provided on the rotor 132, and the inner diameter portion 142a of the rotor case 142 is burred to provide the shaft 2
The rotor case 142 is directly fixed to 0. That is, the rotary shaft 20 is press-fitted into the burring portion 142a of the rotor case 142 while adjusting the air gap G and preloading the inner ring 60 of the bearing 72.

Next, another embodiment of the present invention shown in FIG. 7 will be described. In FIG. 7, the rotor 232 is fixed to the shaft 20 with a screw 250. Also in this embodiment, the rotor boss shown in FIG. 1 is not provided, but instead, the inner diameter of the rotor case 242 is burred, the shaft 20 is inserted into the burring portion 242a, and the inner ring 60 of the bearing 72 is urged by the spring 70. Is applied to the air gap G and the air gap G between the stator 34 and the magnet 44 is adjusted.

When the proper bearing preload and air gap G can be adjusted in this way, the rotor case 242
Are fixed to the rotary shaft 20 with screws 250.
As a result, the rotor 232 can be more reliably fixed to the rotating shaft 20.

As described above, in the embodiment of the present invention, the coil spring is provided on the outer peripheral portion of the shaft between the rotor boss and the ball bearing, or on the outer peripheral portion of the shaft between the rotor and the ball bearing. The preload control becomes much easier than that of the above motor. Further, since the air gap between the rotor magnet and the stator can be adjusted when the rotor is press-fitted, there is an advantage that the conventionally used spacer can be eliminated and the cost can be reduced.

Further, it is only necessary to provide an urging means also called an elastic system in place of the ring used conventionally, and it is possible to make the shape common to a motor having a rotor boss with another bearing structure, which is the same as the conventional one. The motor of the embodiment of the present invention can be assembled on the manufacturing line of Although it is conceivable to provide the coil spring 70 between the two sets of bearings 50 and 72, the shaft of the rotary drum 10 can be improved by applying the motor of the present invention as compared with setting the coil spring in this way. The length in the direction can be shortened.

The present invention is not limited to the above embodiment. For example, instead of the coil spring 70,
It is also possible to use other types of springs, such as leaf springs and wave washers.

[0034]

As described above, according to the present invention, there is provided a motor in which preload control of the bearing is remarkably easy, the air gap can be easily set, and the cost can be reduced. Is intended.

[Brief description of drawings]

FIG. 1 is a VT with a preferred embodiment of the motor of the present invention.
The figure which shows the drum for R.

FIG. 2 is a diagram showing a part of a lower drum of the drum of FIG.

FIG. 3 is a diagram showing a state in which a bearing is attached to a part of the lower drum of FIG.

FIG. 4 is a view showing a state in which a shaft is press-fitted into an inner ring of the bearing mounted in FIG. 3 and a spring is attached to the shaft.

FIG. 5 is a diagram showing a state in which a rotor is fixed to a shaft.

FIG. 6 is a diagram showing another embodiment of the motor of the present invention.

FIG. 7 is a diagram showing yet another embodiment of the present invention.

FIG. 8 is a diagram showing a conventional VTR drum motor.

[Explanation of symbols]

 10 VTR rotating drum 12 upper drum 14 lower drum 20 rotating shaft 32 rotor 34 stator 40 rotor boss 42 rotor case 44 magnet 50,72 bearing 52,60 inner ring 54,62 outer ring G air gap

Claims (4)

[Claims] 1. A motor comprising a rotating shaft, a rotor fixed to the rotating shaft, and a bearing provided in association with the rotating shaft and a stator, wherein an inner ring of the bearing is arranged on the rotating shaft. When,
A motor, comprising: a biasing means between the bearing and the inner ring. 2. The motor according to claim 1, wherein the biasing means is a coil spring. 3. The fixed drum of a rotary drum is integrally fixed to the stator.
The motor described in. 4. The motor according to claim 2, wherein the biasing means is arranged along the outer peripheral portion of the rotating shaft.