JPH08289498A - Motor fan - Google Patents

Abstract

PURPOSE: To prolong the service life of bearing by providing the outer ring of single row deep groove ball bearing on the load side with a coil spring for applying a load axially on the side opposite to the load side thereby protecting the surface of raceway against local abrasion owing to vibration of the bearing in a motor fan during stoppage. CONSTITUTION: A load side bracket 6 is provided with a part 12 for holding a coil spring 10 which applied, along with an intermediate seat 11, a load in the axial direction on the side opposite to the load to the load side outer ring 2a of a single row deep groove ball bearing. Consequently, the ball 2c and the inner ring 2b are shifted to the side opposite to the load thus eliminating the gap between the inner and outer rings 2b, 2a and pushing the rotary shaft 4 axially at some contact angle toward the side opposite to the load. Since the contact points between the ball 2d and the inner and outer rings 2b, 2a are subjected constantly to resilient compressive force, rigidity is increased at the time of stoppage and the rotary shaft 4 is prevented from resonating to the vibration at the time of starting an electric rotating machine or the vibration produced through operation of a motor fan.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric fan in which a rotary shaft of an electric motor is supported by a single-row deep groove ball bearing and a fan is attached to one end of the rotary shaft.

[0002]

2. Description of the Related Art For example, for cooling windings of a rotating machine,
There is a blower that blows air from the outside to cool it. An electric fan is used as a blower in this case. FIG. 5 shows an electric fan 8 used for cooling the rotating machine. The electric fan 8 is horizontally arranged on the outer peripheral side of the stator frame 9 of the rotating machine, and is vertically installed between the upper brackets 13.

The electric fan 8 is not always in operation all the components attached to the rotating machine. It is only necessary to blow a necessary air volume according to the load of the rotating machine. 8 is also operated with a reduced number.
Accordingly, the electric fan 8 is stopped even when the rotating machine is operating. The electric fan 8 that is stopped
Although it is in a state where it does not receive the thrust load that it receives during its operation, it receives an exciting force due to the vibration of the rotating machine and other electric fans 8 during operation.

A single row deep groove ball bearing is generally used for the bearing device such as the electric fan 8. This is because the single-row deep groove ball bearing can be loaded with thrust load in both directions of radial load, has a small friction torque, and has high speed transfer, low noise, and low vibration.

FIG. 6 shows an electric fan 8 using such a single-row deep groove ball bearing. A single row deep groove ball bearing 2 is provided on a rotating shaft 4 of the electric motor. The single-row deep groove ball bearing 2 is supported by a bracket 6 via a preload spring 3. A rotor 5 of an electric motor is attached to the rotary shaft 4, and a fan 1 as a load is attached to one end of the rotor 5.

[0006]

However, when the single-row deep groove ball bearing 2 is not subjected to thrust load, a radial gap 7 is formed between the outer ring 2a or the inner ring 2b and the ball 2c as shown in FIG. . In order to eliminate it, the normal preload spring 3
However, the vibration cannot be suppressed because the vibration force generated by the rotating machine and the electric fan 8 during operation causes a vibration force. Further, since a counter spring is used as the normal preload spring 3 and the outer ring 2a of the single row deep groove ball bearing 2 on the free side is pressed by the anti-load side, the weight cannot be adjusted. Therefore, when the preload is not too great and the load is not optimal, the inner ring 2b, the ball 2c, and the outer ring 2a may be damaged by friction during operation.
Flaking occurs at the parts that come into contact with.

On the other hand, if the rotating machine is running and the electric fan 8 is stopped when the rotating machine is running, local wear on the surface of the partial raceway in which the inner ring 2b and the outer ring 2a contact due to vibration due to long-term operation. Fretting occurs, and the single-row deep groove ball bearing 2 of the bearing device damages the surfaces of the outer ring raceway and the inner ring raceway and reduces the bearing life.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electric fan in which local wear of a raceway surface due to vibration of a bearing device of an electric fan during stoppage is prevented and a bearing life is extended.

[0009]

According to a first aspect of the present invention, an outer ring of a single-row deep groove ball bearing on a load side to which a fan of an electric motor is attached is attached to an outer ring of the outer ring opposite to the load side. It is provided with a coil spring for applying a load to.

According to a second aspect of the present invention, a coil spring for applying a load in the axial direction of the load side to the outer ring of the single row deep groove ball bearing on the opposite side of the load side to which the fan of the electric motor is attached is opposite to the load side. Is provided.

According to a third aspect of the present invention, the load applied by the coil spring is the sum of the rotor weight of the electric motor fan and the fan weight.

[0012]

According to the first aspect of the invention, the outer ring of the bearing on the load side to which the fan is attached is constantly loaded by the coil spring to make the gap negative, and the elastic compression force is constantly applied to the contact point between the ball, the outer ring and the inner ring. I will receive it. Therefore, the rigidity at the time of stop is increased, and the vibration of the shaft due to resonance is prevented with respect to the vibration at the startup operation of the rotating machine and the vibration caused by the operation of other electric fans.

According to the second aspect of the invention, a load is constantly applied to the outer ring of the bearing on the opposite side to the load side, on which the fan is mounted, by the coil spring to keep the gap in a negative state, and the balls, the outer ring and the inner ring are separated from each other. Make the contact point constantly subject to elastic compression. Therefore, as in the case of claim 1, the rigidity at the time of stop is increased, and the vibration of the shaft due to resonance is prevented against the vibration at the start-up operation of the rotating machine and the vibration due to the operation of the other electric fan.

According to the third aspect of the present invention, the load is obtained by adding the rotor weight of the electric fan and the fan weight, and the vibration is generated even if a vibrating force is applied due to vibration of the rotating machine or another electric fan in operation. The condition is the same as that of a stand-up electric fan that can be suppressed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of the present invention. A single row deep groove ball bearing 2 is provided on a rotating shaft 4 of the electric motor. The single-row deep groove ball bearing 2 is supported by a bracket 6. The rotor 5 of the electric motor is attached to the rotary shaft 4, and the fan 1 is not shown in FIG.
The fan 1 is attached to the right side of the figure. Therefore, the right side is the load side and the left direction is the anti-load side.

As can be seen from FIG. 1, the load side bracket 6 is provided with a holding portion 12 for accommodating the coil spring 10, and the coil spring 10 and the intermediate seat 11 are used to counter-load the load side outer ring 2a of the single row deep groove ball bearing 2. The weight is added in the axial direction of the side.

As described above, since the outer ring 2a of the deep groove ball bearing 2 on the mounting side of the load side fan 1 is constantly loaded by the coil spring 10 in the axial direction of the anti-load direction, the load as shown in FIG. The outer ring 2a of the side deep groove ball bearing 2 moves to the anti-load side. That is, the ball 2c and the inner ring 2b are moved to the anti-load side, the gap between the inner ring 2b and the outer ring 2a and the ball 2c is eliminated, and the rotary shaft 4 is pushed in the axial direction of the anti-load side with a contact angle. . As a result, the inner ring 2b of the single-row deep groove ball bearing 2 on the anti-load side is also pushed, and the outer ring 2a of the bearing on the anti-load side also moves.
The gap between b and the outer ring 2a and the ball 2c is eliminated.

Therefore, according to this first embodiment, the ball 2
At the contact points between c and the outer ring 2a and the inner ring 2b, the elastic compression force is constantly received, the rigidity at the time of stop is increased, and the vibration at the start-up operation of the rotating machine and the vibration due to the operation of other electric fans are It is possible to prevent vibration of the rotating shaft 4 due to resonance.

FIG. 3 is a block diagram showing the second embodiment of the present invention. In contrast to the first embodiment, this second embodiment is provided with a holding portion 12 for accommodating the coil spring 10 in the anti-load side bracket 6, and the anti-load of the single row deep groove ball bearing 2 is constituted by the coil spring 10 and the intermediate seat 11. A load is applied to the side outer ring 2a in the axial direction of the load side.

That is, the rotating shaft 4 of the electric motor is provided with the single-row deep groove ball bearing 2. This single row deep groove ball bearing 2
It is supported by the bracket 6. A rotor 5 of an electric motor is attached to the rotary shaft 4, and the fan 1 is omitted in FIG. 3, but the fan 1 is attached to the right side of the drawing. Therefore, the right side is the load side and the left direction is the anti-load side. As can be seen from FIG. 3, the anti-load side bracket 6 is provided with a holding portion 12 for accommodating the coil spring 10, and the single row deep groove ball bearing 2 includes the coil spring 10 and the intermediate seat 11.
A load is applied to the anti-load side outer ring 2a in the axial direction of the load side.

In the electric fan 8 thus constructed, the outer ring 2a of the deep groove ball bearing 2 on the non-load side is constantly loaded by the coil spring 10 in the axial direction of the load direction.
Therefore, the outer ring 2a of the deep groove ball bearing 2 moves to the load side on the counter load side. As a result, the balls 2c and the inner ring 2b are moved as shown in FIG. 4, and the gap between the inner and outer rings and the balls is eliminated,
Further, the rotating shaft 4 is pushed in the axial direction of the load side with a contact angle. In other words, the inner ring 2b of the deep groove ball bearing 2 on the load side
Is also pushed, and the bearing on the load side also moves as shown in FIG. As a result, the inner ring 2b, the outer ring 2a, and the balls 2c
Therefore, the gap between the ball 2c and the outer ring 2a and the inner ring 2b is constantly subjected to the elastic compressive force. As a result, rigidity at the time of stoppage is increased, and vibration of the rotary shaft 4 due to resonance can be prevented against vibration during start-up operation of the rotating machine and vibration due to operation of the other electric fan 8.

In the horizontal electric fan 8 having the coil spring 10, the coil spring 10 has a spring constant k.
The load f obtained from the displacement x is the same as mg obtained by multiplying the mass m of the rotor 5 of the electric fan 5 and the mass of the fan 1 by the gravitational acceleration g.

F = kx = mg (1) By setting the spring constant k of the coil spring 10 as in the equation (1), the standing electric fan 8 having no device to which a load is applied and the coil spring 10 are connected. Under the same conditions as the horizontally installed electric fan 8, the vibration can be suppressed even if a vibrating force is applied due to the vibration of the rotating machine or another electric fan 8 in operation. In addition, the load can be easily calculated. The displacement amount x can also be adjusted to a length that obtains an optimum load by the free length of the spring and the adjustment allowance.

Further, an electric fan 8 attached to the rotating machine
As an electric fan 8 having a coil spring 10 according to the present invention is used as the horizontal electric fan 8 and an electric fan 8 having no ordinary coil spring 10 of the same type is mixed as the vertical electric fan 8. Since the vertical axis electric fan and the horizontal electric fan have the same operating conditions and load conditions when stopped, the life of the bearings can be made uniform and the maintenance and replacement times can be aligned.

[0025]

As described above, according to the invention of claim 1,
Since the load is always applied to the outer ring of the deep groove ball bearing on the fan mounting side on the load side in the axial direction of the anti-load direction by the coil spring, the outer ring of the deep groove ball bearing on the load side moves to the anti-load side and the inner and outer rings There is no gap. Further, since the shaft is pushed in the axial direction on the anti-load side with a contact angle, the clearance between the inner and outer races and the balls is eliminated as in the bearing on the load side. Therefore, the contact transfer elastic compression force between the ball and the outer ring can be constantly received, so the rigidity at the time of stop is increased, and resonance occurs for vibration during start-up operation of the rotating machine and vibration due to the operation of other electric fans. Vibration of the shaft can be prevented.

According to the second aspect of the present invention, since a coil spring constantly applies a load in the axial direction of the load direction to the outer ring of the fan mounting side groove groove on the counter load side, the counter groove side groove groove on the counter load side. The outer ring of the bearing moves to the load side, eliminating the gap between the inner and outer rings and the balls. Further, since the shaft is pushed in the axial direction of the load side with a contact angle, the gap between the inner and outer races and the ball is eliminated as in the bearing on the non-load side. Therefore, similarly to the invention of claim 1, the contact transfer elastic compression force between the balls and the outer ring and the inner ring can be constantly received, so that the rigidity at the time of stop is increased, and the vibration at the time of start-up operation of the rotating machine and other It is possible to prevent the vibration of the shaft due to resonance with respect to the vibration caused by the operation of the electric fan.

According to the third aspect of the present invention, in the horizontal electric fan mounted on the rotating machine, the load applied by the spring constant of the coil spring is the sum of the rotor weight and the fan weight of the electric fan. As a result, the vibration can be pushed even when an exciting force is applied due to the vibration of the rotating machine or another electric fan during operation, and the adjustment is easy and the load can be easily calculated.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a single-row deep groove bearing according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram showing a second embodiment of the present invention.

FIG. 4 is an explanatory view of single-row deep groove bearings according to first and second embodiments of the present invention.

FIG. 5 is an explanatory view when an electric fan is used as a ventilation device for cooling a rotating machine.

FIG. 6 is an explanatory view of a conventional electric fan.

FIG. 7 is an explanatory view of a single-row deep groove bearing in a conventional example.

[Explanation of symbols]

 1 Fan 2 Deep Groove Ball Bearing 2a Outer Ring 2b Inner Ring 2c Ball 3 Preload Spring 4 Rotating Shaft 5 Rotor 6 Bracket 7 Radial Gap 8 Electric Fan 9 Stator Frame 10 Coil Spring 11 Middle Seat 12 Holding Part 13 Upper Bracket

Claims (3)

[Claims] 1. An electric fan in which a rotating shaft of an electric motor is supported by a single-row deep groove ball bearing, and a fan is attached to one end of the rotating shaft, wherein the single-row deep groove ball on the load side to which the fan of the electric motor is attached. An electric fan characterized in that a coil spring is provided on an outer ring of the bearing for applying a load in an axial direction on the side opposite to the load side opposite to the load side. 2. An electric fan in which a rotating shaft of an electric motor is supported by a single-row deep groove ball bearing and a fan is attached to one end of the rotating shaft, the anti-load being opposite to the load side of the electric motor on which the fan is attached. A coil spring for applying a load in the axial direction of the load side is provided on the outer ring of the single row deep groove ball bearing on the side. 3. The electric fan according to claim 1, wherein the load applied by the coil spring is the sum of the rotor weight and the fan weight of the electric motor fan.