JPH10339295A - Blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb the vibration when the natural frequency of the vibration system of a fan and a motor is resonated with the frequency of the electromagnetic excitation force of the motor by fixing an inertia member having a center hole in which a rotary shaft of the motor is inserted and having the rotational inertia not less than that of a rotor of the motor to the rotary shaft together with the fan. SOLUTION: A motor 2 to derive a fan 1 in an indoor unit of an air conditioner for business use is fixed to a top plate 3 through a vibration isolating rubber 23. A heat exchanger 4 is arranged on an outer circumferential part of the fan 1, and fixed to the top plate 3. A water receiver 5 for the drain is arranged on a lower part of the heat exchanger 4. A steel damper 8 is arranged on an upper part of a hub 32 between a boss part 33 of the fan 1 and a blade part 11, i.e., on a non-flow passage side of a supply passage, and inserted in a rotary shaft 9 together with the fan 1, and fixed to the rotary shaft by fitting screws. The steel damper 8 is provided to change the natural frequency in the rotational direction and the vibration mode so that the rotational inertia of the damper is larger than that of the rotor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower used as a blower or a blower, and is suitable for a structure for reducing electromagnetic vibration noise generated when a motor for driving a blower / fan is used as a vibration source. .

[0002]

2. Description of the Related Art For example, Japanese Patent Application Laid-Open Nos. 61-275597, 4-86398, and 4-
JP-A-203296 and JP-A-7-103191 are known.

In Japanese Patent Application Laid-Open No. 61-275597, resonance of a blower is prevented by sandwiching a boss of a metal blade and a spinner via an elastic material such as rubber.

In Japanese Patent Application Laid-Open No. 4-86398, an elastic body is provided between a boss portion of a fan fixed to a rotating shaft of a motor and a hub holding blades provided on the outer periphery of the boss portion. The resonance of the blower is prevented.

In Japanese Patent Application Laid-Open No. 4-203296, a fastening portion for fixing a fan to a rotating shaft of a motor with a fan cap is configured by mounting an intervening member such as a resin having a vibration damping action on the fan and the fan cap. This prevents resonance of the blower and reduces noise.

In Japanese Patent Application Laid-Open No. Hei 7-103191, a fan fixed to a rotating shaft of a motor is sandwiched between two plates sandwiching rubber to prevent transmission of vibration from the motor to the fan, thereby reducing noise. .

[0007]

The noise of the blower is roughly divided into a fluid noise of a fan as a blower / absorber and an electromagnetic vibration sound generated by a fan driving motor as a vibration source. Among them, the electromagnetic vibration sound generated due to the electromagnetic excitation force of the motor has an outstanding single frequency component and is perceived as harsh by humans, so its reduction is indispensable.

The electromagnetic vibration sound is generated when an electromagnetic excitation force of a motor for driving a fan is transmitted to the fan, and the fan which is a sound generator vibrates to generate noise. As a means for reducing electromagnetic vibration noise so far, as described in the related art, a fan is fixed to the rotation shaft of a fan drive motor, which is a vibration source, via an elastic body such as a vibration-proof rubber or resin. Means for damping the electromagnetic exciting force propagating to the fan have been generally used.

The problem at this time is that the elastic member is required to have high reliability in order to transmit the rotational torque to the fan via the elastic member. In this case, the whirling vibration increases.

In order to solve these problems, it is desirable to make an elastic body such as a vibration-proof rubber hard. However, from the viewpoint of reducing the electromagnetic vibration noise, it is not desirable to harden the elastic body because the vibration damping performance of the electromagnetic excitation force propagating to the fan deteriorates and the electromagnetic vibration noise increases.

An object of the present invention is to provide a blower that further improves the conflicting problems of reducing electromagnetic vibration noise, increasing reliability, and reducing vibration.

[0012]

Means for Solving the Problems As an alternative to an elastic body such as a vibration isolating rubber or a resin, an inertia member having a center hole inserted into a rotating shaft of a motor and having a rotating inertia higher than that of a motor rotor is rotated together with a fan. Secure to the shaft. Thus, when the natural frequency of the vibration system of the fan and the motor resonates with the electromagnetic exciting force of the motor, the inertia member can absorb the vibration. As a result, the vibration of the fan and the electromagnetic exciting force of the motor can be reduced, and the electromagnetic vibration noise of the blower can be reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.
This will be described with reference to FIG. The figure shows an air blower of the present invention applied to an indoor unit of a commercial air conditioner.

FIG. 1 is a sectional view of an indoor unit of an air conditioner showing an example of an embodiment of the present invention, FIG. 2 is a vibration model of a blower in a rotational direction, and FIG. 3 is an inertia member (a main member of the present invention). FIG. 4 is a perspective view showing an example of the shape of the steel plate damper, and FIG. 5 shows the frequency characteristics of noise when the blower of the present invention is applied. FIG.

The above figures show examples applied to a sending device of a commercial air conditioner. In the present invention, vibration and noise of a rotating body attached to a motor are generated by an electromagnetic exciting force of a driving motor. Applicable to all products.

First, the configuration of a commercial air conditioner indoor unit will be described with reference to FIG. The fan 1 used here is called a turbo fan.

A motor 2 for driving a fan 1 serving as an air blowing / absorbing means is fixed to a top plate 3 via an anti-vibration rubber 23. A heat exchanger 4 is arranged on the outer periphery of the fan 1, and the heat exchanger 4 is also fixed to the top plate 3. Further, a water receiver 5 for drain water is placed below the heat exchanger 4. The indoor unit is suspended in the ceiling of the building by the mounting bracket 30 and the suspension bolts 31 provided on the side plate 6 integrated with the top plate 3, and only the decorative panel 7 can be seen from the room. Reference numeral 8 denotes a steel plate damper, which is a main member of the present invention, and is fixed to the rotating shaft 9 of the motor 2 together with the fan 1. The steel plate damper 8 is characterized in that it is larger than the rotational inertia of the rotor.

FIG. 1 also shows a blowing path of the blower unit. The ventilation path is a path that draws indoor air from below in the figure, passes through the heat exchanger 4 via the blades 11, and blows out the wind from the outer periphery of the panel 7. Since the steel plate damper 8 of the present invention is disposed on the upper portion of the hub 32 between the boss portion 33 and the blade portion 11 in order to hold the blade portion 11 of the fan, that is, on the non-flow path side of the air blowing path, It does not block the air intake path and does not adversely affect fluid performance.

FIG. 2 is a diagram showing a model of a vibration system in the rotation direction of the blower. FIG. 2A shows a case where a steel plate damper is not applied.
(b) applies. The vibration system model includes a rotational inertia 40 of a fan, a rotational inertia 41 of a motor rotor, a spring 42 of a fan, and a spring 43 of a rotating shaft. When a steel plate damper is applied, the model has a damper rotational inertia 44 added as shown in FIG. 2 (b).

FIG. 3 shows a state where the steel plate damper 8 is attached to the blower. FIG. 3 shows a mounting state in a case where the rotational torque from the rotary shaft 9 of the motor is directly transmitted to the fan 1.The steel plate damper 8 is inserted into the rotary shaft 9 together with the fan 1, and is attached together with the flat washers 27a and 27b by the mounting screw 28. Fixed to the rotating shaft 9. For this purpose, the steel plate damper 8 has a hole at the center thereof into which the rotating shaft 9 can be inserted. Steel plate damper 8 is a rotating shaft
The structure is designed so that it comes into contact with the fan 1 at the point of attachment with the fan 9 but does not come into contact with the fan 1 at other parts.

Here, the effects of the present invention will be described.

With respect to the electromagnetic vibration sound, the electromagnetic excitation force from the motor 2 propagates to the fan 1 which is a sound generator, and the fan 1 vibrates to generate noise. The magnitude of the electromagnetic excitation force is the largest at the fundamental frequency (100 Hz or 120 Hz, which is twice the power supply frequency). The higher the frequency, the smaller the excitation force. When the natural frequency of the model of the system is near an integral multiple of the fundamental frequency of the electromagnetic excitation force, resonance occurs, and the electromagnetic vibration sound of the frequency component increases. The cause is that the vibration of the rotor of the motor 2 increases.

In the model of FIG. 2A, there is one natural frequency, and the vibration mode is a mode in which the rotor vibration is larger than the fan vibration. Therefore, when the damper 8 is not applied, the electromagnetic vibration noise increases.

FIG. 2 to which the steel plate damper 8 of the present invention is applied.
In the model of (b), there are two natural frequencies. In one vibration mode, the rotor hardly vibrates, the fan and the damper vibrate, and especially the damper vibration increases. In the other mode, the fan hardly vibrates, the damper and the rotor vibrate, and especially the rotor vibration This is a mode that increases In contrast to FIG. 2 (a), in the former mode, the natural frequency is determined by the fan and the damper, so the natural frequency is low.
In the latter mode, the natural frequency is high because the natural frequency is determined by the rotor and the damper.

As described above, the cause of the increase in the electromagnetic vibration noise is that the vibration of the rotor of the motor 2 is large. By applying the damper of the present invention, the lower-order mode can be a mode in which the rotor does not vibrate, in other words, a mode in which the rotor vibration is absorbed by the damper, and a mode in which the rotor vibrates (higher-order mode). Can be moved to a high frequency range where the excitation force is small.

Further, in a higher-order mode, a mode in which the fan as a sounding body does not vibrate is set.

As described above, the electromagnetic vibration noise can be reduced by the damper of the present invention.

Further, by using the steel plate damper 8 as in the structure of FIG. 3, the rotational torque from the rotary shaft 9 can be directly transmitted to the fan 1 without using a low-reliability member such as rubber or resin which deteriorates greatly over time. High reliability can be ensured due to transmission, and the connection between the rotating shaft 9 and the fan 1 is also rigidly connected to the fan.
The whirling of (1) is also reduced, and the vibration of the indoor unit can be reduced.

In a blower in which the motor shaft is horizontal, the self-weight of the fan also affects the whirling vibration, so that the motor shaft and the fan cannot be soft-coupled and vibration-proof rubber cannot be used. Therefore, there is a problem that the electromagnetic vibration noise becomes large. However, by applying the steel plate damper, the whirling vibration can be reduced by the rigid connection, and the electromagnetic vibration noise can be reduced.

FIG. 4 is a perspective view showing an example of the shape of the steel plate damper 8 of the present invention. When installed on the flow path side, the wind
Since it flows along 32, the shape of the damper only needs to follow the hub so as not to obstruct the flow.

As described above, the steel plate damper is for changing the natural frequency and the vibration mode in the rotational direction, and has the above-mentioned effect if the rotational inertia of the damper is larger than the rotational inertia of the rotor. Therefore, the shape of the steel plate damper 8 may be any shape as long as this condition is satisfied. Therefore, if this condition cannot be satisfied by one member, the damper may be constituted by a plurality of members.

FIG. 5 shows the frequency characteristics of the noise of the blower when the steel plate damper 8 of the present invention is not applied (a) and (b). In the figure, the horizontal axis represents frequency (Hz) and the vertical axis represents noise level (dB). In the frequency characteristics shown in the figure, a random component of almost the same level from low frequency to 1000 (Hz) is the fluid noise component accompanying the rotation of the fan, and the predominant component seen at an integral multiple of 100 (Hz) is the electromagnetic vibration sound component. is there. The noise here is the result when the power supply frequency is 50 (Hz).

In FIG. 5 (a) where no damper is applied, 100 (H) which is an integral multiple of 100 (Hz) which is the fundamental frequency of the electromagnetic exciting force is used.
z), 200 (Hz), 300 (Hz), 400 (Hz), 600 (Hz) frequency components are dominant. In particular, the peak level at 200 (Hz) is large. This is because, as described above, the natural frequency in the rotational direction of the vibration system including the fan 1, the motor 2 and the rotating shaft 9 is around 200 (Hz). Along with that, 100 (Hz), 300 (Hz), 400 (Hz) around it
Frequency components are also outstanding. The level of the electromagnetic vibration sound shown in the figure is a level that is unpleasant and unpleasant even in the sense of hearing.

In FIG. 5 (b) to which the damper is applied, the peaks of the electromagnetic vibration noise are only 100 (Hz) and 200 (Hz), and the peak level of 200 (Hz) can be significantly reduced. I understand. This is due to the effect described above. Since the peak level of the electromagnetic sound in FIG. 5B is equivalent to the overall value of the fluid noise, it is a level that is hardly noticeable even in the sense of hearing.

As described above, by applying the steel plate damper 8 of the present invention to a blower, it is possible to reduce the electromagnetic vibration noise of the blower, and furthermore, to achieve high reliability and low vibration of the air conditioner. Indoor unit can be realized.

FIG. 6 is a sectional view of a blower according to another embodiment of the present invention. This example is a case where the steel plate damper 8 is provided on the flow path side of the air blowing path of the fan 1. As a result, the steel plate damper 8 is no longer caught between the motor 2 and the fan 1 than when the steel plate damper 8 is provided on the non-flow path side, so that the position adjustment such as the centering of the steel plate damper 8 can be easily performed, and The assemblability of the device is improved. Furthermore, the vibration in the rotation direction of the fan 1 and the motor 2 can be absorbed by the steel plate damper 8, and the electromagnetic vibration noise of the blower can be reduced.

FIG. 7 shows still another embodiment, in which a steel plate damper 8 is fixed to a boss 33 of a fan to which the fan 1 and the rotating shaft 9 are fixed by mounting screws 35.

By doing so, the fan 1 is attached to the rotating shaft 9.
Before mounting the fan, it is possible to fix the fan 1 and the steel plate damper 8, eliminating the need to fix the fan 1 and the steel plate damper 9 to the rotating shaft 9 at the same time. Is improved. Further, it is possible to balance the fan and the damper in an assembled state, and there is an advantage that the whirling vibration can be reduced.

FIG. 8 shows still another embodiment, in which a steel plate damper 8 is fixed to a rotating shaft 9 of a motor. By doing so, it is possible to fix the rotating shaft 9 and the steel plate damper 8 before attaching the fan 1 to the rotating shaft 9, without having to fix the fan 1 and the steel plate damper 9 to the rotating shaft 9 at the same time. As a result, the assemblability of the blower, especially the dimensional accuracy during assembling, is improved.

FIG. 9 is a side view ((a) view) and an AA cross-sectional view ((b) view) showing still another embodiment, in which a steel plate damper is applied to a sirocco fan (multi-blade fan). It was done.

The sirocco fan is composed of a boss 33 fixed to the rotating shaft 9, a multi-blade blade 14 and a core plate 13 holding the blade 14, and the rotational torque of the motor is transmitted to the boss 33. Rotate the sirocco fan. Here, by fixing the steel plate damper 8 to the rotating shaft 9 together with the boss portion 33, it becomes possible for the vibration in the rotation direction of the fan 1 and the data 2 to be absorbed by the steel plate damper 8, thereby reducing the electromagnetic vibration noise of the blower. Can be reduced.

FIG. 10 is a plan view (FIG. 10A) and a sectional view taken along line AA (FIG. 10B) showing still another embodiment, in which a steel plate damper is applied to a propeller fan (axial flow fan). It was done.

In the propeller fan, similarly to the above-described fan, the rotational torque of the rotating shaft 9 is transmitted to the boss 33 by the D cut portion 34, and the blade 19 rotates. Where the boss
By fixing the steel plate damper 8 to the rotating shaft 9 together with 33, the vibration in the rotation direction of the fan 1 and the data 2 can be absorbed by the steel plate damper 8, and the electromagnetic vibration noise of the blower can be reduced. .

[0044]

According to the present invention, the electromagnetic vibration noise of the blower can be reduced. Further, the electromagnetic noise can be reduced without using rubber, resin, or the like which deteriorates greatly over time, so that reliability is improved. Further, the coupling between the rotating shaft of the motor and the fan is rigidly connected, so that there is an effect that the whirling of the fan is small and the equipment having the blower can be reduced in vibration.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view when a blower according to an embodiment of the present invention is applied to an indoor unit of an air conditioner.

FIG. 2 is a diagram showing a model of a vibration system in a rotation direction of the blower of the present invention.

FIG. 3 is a sectional view showing a state in which a steel plate damper, which is a main member of the present invention, is attached to a blower.

FIG. 4 is a perspective view showing one shape of a steel plate damper which is a main member of the present invention.

FIG. 5 is a diagram illustrating frequency characteristics of noise of a blower.

FIG. 6 shows another embodiment of the present invention, and is a cross-sectional view in the case where a steel plate damper is provided on the flow path side of an air intake and intake passage.

FIG. 7 is a cross-sectional view showing still another embodiment and showing a state in which a steel plate damper is mounted on a blower when a steel plate damper is mounted on a boss of a fan.

FIG. 8 is a cross-sectional view showing a still further embodiment and showing a state where the steel plate damper is mounted on a blower when the steel plate damper is mounted on a rotating shaft of a motor.

FIG. 9 shows still another embodiment, in which a steel plate damper is applied to a multi-blade fan (sirocco fan).

FIG. 10 is a view showing still another embodiment, in which a steel plate damper is applied to an axial fan (propeller fan).

[Explanation of symbols]

1 ... Fan, 2 ... Drive motor, 8, 8a, 8b, 8c ...
Steel plate damper, 9: rotating shaft, 11: blade, 32: fan hub, 33: fan boss.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Makoto Nagai 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture Inside Air Conditioning Systems Division, Hitachi, Ltd. (72) Inventor Hiroyasu Yoneyama 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture Hitachi Shimizu Engineering Co., Ltd. Inside

Claims (6)

[Claims] 1. A fan having a shaft hole and a blade, and a blower in which a rotation shaft of a fan driving motor is inserted into the shaft hole, and wherein the fan is fixed to the rotation shaft at a fan boss portion. A blower having a center hole inserted into the rotating shaft, and an inertia member having a rotating inertia higher than that of the rotor of the motor is fixed to the rotating shaft together with the fan. 2. A fan having a shaft hole and blades, and a blower in which a rotation shaft of a fan drive motor is inserted into the shaft hole, and wherein the fan is fixed to the rotation shaft at a fan boss portion. A blower having a center hole inserted into the rotating shaft, and an inertia member having a rotation inertia higher than that of the rotor of the motor is fixed to the fan boss portion. 3. A fan having a shaft hole and blades, and a blower in which a rotation shaft of a fan driving motor is inserted into the shaft hole, and wherein the fan is fixed to the rotation shaft at a fan boss portion. A blower having a center hole inserted into the rotating shaft, and an inertia member having a rotating inertia higher than that of the rotor of the motor is fixed to the rotating shaft. 4. The blower according to claim 1, wherein the inertial member is constituted by at least two or more members. 5. The blower according to claim 1, wherein the inertia member is provided on a flow path side of a blower / suction path of the fan. 6. The air blower according to claim 1, wherein the inertia member is provided on a non-flow path side of a fan air blowing / blowing path.