JPH05256299A - Blower - Google Patents

Abstract

PURPOSE:To provide a blower equipped with a fan wherein a bad influence is prevented from being given to productivity by performing effective noise reduction with no apprehension of material deterioration over a long period. CONSTITUTION:A blower is formed by mounting a fan 3 on a rotary shaft 2 of an electric motor l1 driven by a frequency or phase control power supply for variably setting a rotational speed. This fan 3 comprises a cylindrical boss part 4 directly mounted on the rotary shaft 2 of the electric motor 1, cylindrical hub part 6 positioned with a space provided in the periphery of this boss part to integrally provide the base end part of a blade 7 of actually performing air blow action to a peripheral surface of this boss part and a plurality of bridge ribs 5A, 5B integrally bridged to be provided by two sets along the axial direction between these boss part peripheral surface and hub part internal peripheral surface and also opposed between mutual pitches by displacing a position respectively along the peripheral direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower installed in, for example, an air conditioner, equipped with a propeller fan and a sirocco fan, and particularly capable of variably setting the fan rotation speed.

[0002]

2. Description of the Related Art For example, an air conditioner requires a blower in which a propeller fan or a sirocco fan is attached and fixed to a rotary shaft of an electric motor in order to blow heat exchange air to the heat exchanger. Then, in such an air conditioner, it is convenient to be able to variably set the fan rotation speed in order to obtain the air flow rate adapted to the heat exchange capacity. In order to variably set the fan rotation speed of the blower, it is necessary to control the rotation speed of the electric motor that rotationally drives the fan.

There are various actual motor rotation speed control means. For example, when the electric motor is an induction motor,
A power supply voltage control method, a power supply frequency control method, a switching control method using a motor winding tap, a power supply frequency wave number control method, or a phase control method can be considered.

In particular, in blowers used for air conditioners, the wave number control system or phase control system tends to be frequently used based on the fact that power supply control by thyristors has become easy in recent years.

The wave number control method and the phase control method can perform finer control as compared with the power supply voltage control method and can be provided at a lower cost than the power supply frequency control method.
Stepless control is possible compared with the switching control method using the motor winding tap.

The above wave number control method is, for example, as shown in FIG.
As shown in, a wave of a fixed ratio, that is, ⅓ here, is not output. That is, the voltage is set to zero, and control is performed to output only a 2/3 wave, resulting in a reduction of the rotation speed to 2/3 of the maximum rotation speed. The phase control method is shown in FIG.
As shown in Fig. 5, the control is such that the output voltage in a certain proportion of the time waveform of the power supply wave, here about 1/4 of the time, is set to zero and only the remaining about 3/4 of the time is output. As a result, the rotation speed can be reduced to about 3/4 of the maximum rotation speed.

[0007]

By the way, the rotation speed control of the electric motor by the wave number control method or the phase control method is more complicated than the driving by the stable sine wave waveform as in other control methods. Is forcibly destabilized.

Therefore, due to the distortion of the waveform, pulsation of the rotating torque in the electric motor, abnormal vibration, resonance, etc. are likely to occur, and these are transmitted to the fan and cause noise.

In order to eliminate this kind of defect, conventionally,
For example, a fan boss that is attached and fixed to the rotating shaft of an electric motor, and a blade blade that actually blows air,
A structure in which elastic members such as a rubber material are connected is adopted.

However, although this type of structure has a certain noise damping effect, it is an elastic material, so that it is prone to early deterioration, the manufacturing variations are large, the manufacturing process is increased, and the productivity is lowered. However, it newly occurred. Therefore, another configuration without these problems is desired.

The present invention has been made in view of the above circumstances, and it is an object of the present invention that even if an electric motor is driven by a power source whose rotational speed is variably set, there is a risk of material deterioration for a long period of time. Another object of the present invention is to provide a blower equipped with a fan that effectively reduces noise and does not adversely affect productivity.

[0012]

In order to achieve the above object, the present invention is configured such that an electric motor is driven by a power source that variably sets the number of revolutions, and a fan is attached and fixed to the rotary shaft of the electric motor. In the blower, the fan is
A cylindrical boss is directly attached to the rotating shaft of an electric motor, a cylindrical hub is positioned with a gap on the outer circumference of the boss, and the blade blade base that acts as a blower on the outer peripheral surface of the hub. The end portions are integrally provided, and two sets are provided along the axial direction between the outer peripheral surface of the boss portion and the inner peripheral surface of the hub portion,
The blower is characterized in that a plurality of bridge ribs, which are displaced from each other along the circumferential direction and are opposed to each other between the pitches, are installed.

Thus, according to the present invention, in controlling the rotation speed of the electric motor, even when a waveform other than a sine waveform is applied, two sets of a plurality of bridges are installed between the outer peripheral surface of the boss portion and the inner peripheral surface of the hub portion. The bridge rib absorbs the vibration of the electric motor and attenuates the noise.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 2, the rotating shaft 2 of the electric motor 1
A fan, here a propeller fan 3, is attached and fixed to form a blower.

The electric motor 1 is an induction motor which is generally used frequently, and in order to control the rotation speed, the wave number control method or the phase control method as described above is adopted.

The propeller fan 3 is, for example, press-fitted and fixed to the rotary shaft 2 of the electric motor 1, or is screwed to the boss 4, and the outer periphery of the boss 4 has two sets of bridge ribs 5A described later. , 5B, and a hub portion 6 concentric with the boss portion 4 and a plurality of blade blades 7 provided on the outer peripheral surface of the hub portion 6.

Such a propeller fan 3 is integrally molded with the same material, for example, an AS resin material containing glass fiber. In other words, it is an integrally molded product which is manufactured by using a resin molding machine such as an injection machine.

Therefore, it is relatively easy to increase the number of products to be produced, and it is suitable for mass production of household items and the like, and is excellent in strength and precision. Basically, it ’s highly reliable,
In addition, it is possible to provide a propeller fan that hardly generates vibration and noise.

The boss portion 4 and the hub portion 6 have a cylindrical shape whose axial lengths are substantially the same, and the boss portion 4 has a large wall thickness because it is attached to the rotary shaft 2. The hub portion 6 has a wall thickness that does not hinder strength in supporting the blade blades 7 that actually perform air blowing.

As described above, the two sets of bridge ribs 5A and 5B are integrally erected between the outer peripheral surface of the boss portion 4 and the inner peripheral surface of the hub portion 6, but the same here. As shown in the figure, two sets are provided along the axial direction, and the two sets are provided with their positions displaced along the circumferential direction.

Moreover, as shown in FIG. 1, the bridge ribs 5A and 5B of each set are arranged along the circumferential direction, here 90 °.
A total of four sheets are provided at intervals, and each is set at a position facing each other between the pitches.

That is, if there are four bridge ribs 5A on the front side (anti-electric motor side) that are hatched in the figure in the horizontal direction and the vertical direction in the figure, the back side (electric The bridge ribs 5B on the motor side) face each other with their positions shifted by 45 °.

In each of the bridge ribs 5A and 5B, the dimension of the narrowest portion along the axial direction is set to l _2, and the dimension of the thinnest portion along the circumferential direction is set to l ₁ . These dimension setting parts are holes 4a for mounting the rotary shaft 2 of the boss 4.
Is more than twice the diameter D.phi.
That is, the diameter of the thinnest portion of each bridge rib 5A, 5B is four times or more the outer diameter of the rotary shaft 2.

The bridge ribs 5A, 5 as described above
This is a propeller fan 3 integrally provided with B, and energizes the electric motor 1 so as to be rotationally driven and blown. The vibrations of the electric motor 1 are transmitted to the bridge ribs 5A and 5B.
Are absorbed and reduced, and are prevented from being transmitted to the blades 7 to suppress the generation of noise. The bridge ribs 5A, 5
Since the narrowest portion of B along the axial direction and the thinnest portion along the circumferential direction are set in the middle portion, the rotational force M applied to this portion is M = F ₁ × D
/ 2 = F ₂ × d / 2.

D: diameter of rotary shaft 2, F ₁ : rotary shaft 2
In the direction of rotation, d: diameter of the thinnest portion of the bridge ribs 5A, 5B, F ₂ : force applied to the thinnest portion of the bridge ribs 5A, 5B.

From the above conditions, by setting 4D <d, F ₁ > 4F ₂ , that is, F ₂ <1 /
It is 4F ₁ . Therefore, the bridge rib 5A,
The force applied to 5B can be made smaller than the equivalent force of the outer diameter of the rotating shaft 2.

Although it is effective to further increase the diameter d of the thinnest portion of the bridge ribs 5A and 5B,
Since the diameter of the hub portion 6 increases accordingly, which leads to deterioration of air blowing characteristics, it is necessary to set the dimension to an optimum value.

The bridge ribs 5A and 5B of each set are
It is provided so as to be displaced along the axial direction, and is provided so as to be opposed to each other between the pitches along the circumferential direction. Therefore, the bending strength in the vertical direction of the shaft-to-fan like the propeller fan 3 becomes extremely strong, and the effect of absorbing the vibration generated from the electric motor 1 is maintained even if the bridge ribs 5A and 5B are made sufficiently thin.

In conclusion, such a bridge rib 5
In the case of the propeller fan 3 having A and 5B, since the rotation speed is controlled, even when a waveform other than the sinusoidal waveform such as the wave number control method or the phase control method is applied to the electric motor 1, the motor generated thereby is generated. Vibration can be prevented from being transmitted to the propeller fan 3. Therefore, these control methods can be utilized. A propeller fan having a structure as shown in FIG. 4 may be used.

In this case, the intermediate hub portion 8 is integrally provided between the boss portion 4A and the hub portion 6A. And the boss 4
Bridge rib 1 that is installed between A and the intermediate hub portion 8A
Two sets of 5A and 15B are provided along the axial direction, and the positions of the 5A and 15B are set so that they are offset from each other along the circumferential direction so as to face each other.

Here, each set of bridge ribs 15A, 1
5B are provided at 90 ° intervals in the circumferential direction, and a total of four bridge ribs 5A are provided. If there are four bridge ribs 15A on the hatching side in the horizontal direction and four bridge ribs on the vertical direction, the bridge ribs on the non-hatching side are provided. 15B faces each other with their positions shifted by 45 °.

The bridge ribs 25A and 25B provided between the intermediate hub portion 8 and the hub portion 6A are also provided in two sets along the axial direction, and the bridge ribs 25A and 25B are displaced along the circumferential direction. The pitch is opposed to each other.

However, these bridge ribs 25A, 25
The position along the circumferential direction of B is the bridge ribs 25A, 25B of each set between the boss portion 4A and the intermediate hub portion 8 described above.
And are provided at a 45 ° interval in the circumferential direction.

Such bridge ribs 15A, 15B,
With 25A and 25B, a so-called zigzag system path is configured, and even if the vibration of the electric motor 1 is transmitted through the rotary shaft 2, the effect of more effectively absorbing the vibration can be obtained. Propeller fan 3 shown in FIGS. 1 and 2
Even with the propeller fan 3A shown in FIG. 4, there is no problem in the mold structure. Furthermore, selecting a softer mold material with the bridge rib as another piece is more effective in absorbing the vibration of the electric motor 1.

[0035]

As described above, according to the present invention, the cylindrical boss portion is directly attached to the rotary shaft of the electric motor, and the cylindrical hub portion is positioned with a gap on the outer periphery of the boss portion. The base end portion of the blade blade, which has a function of blowing air, is integrally provided on the outer peripheral surface of the hub portion, and two sets are provided along the axial direction between the outer peripheral surface of the boss portion and the inner peripheral surface of the hub portion, and in the circumferential direction. Since a fan was constructed by installing a plurality of bridge ribs that are displaced along each other so as to face each other between the pitches, even if the electric motor is driven by a power supply that variably sets the rotation speed, the fan itself Therefore, there is no fear of material deterioration, the electric motor efficiently absorbs vibration to effectively reduce noise, and there is an effect that a fan that does not adversely affect productivity is provided.

[Brief description of drawings]

FIG. 1 is a partially longitudinal front view of a fan according to an embodiment of the present invention.

FIG. 2 is a side view of the embodiment, in which a part of the blower is omitted.

FIG. 3A is a rotation speed control of an electric motor,
Waveform diagram of waveform control. (B) is a waveform diagram of phase control, which is the rotation speed control of the electric motor.

FIG. 4 is a partial vertical cross-sectional view of a fan of a modified example.

[Explanation of symbols]

1 ... Electric motor, 2 ... Rotating shaft, 3 ... Propeller fan, 4
... Boss section, 7 ... Blade blade, 6 ... Hub section, 5A, 5B ...
Bridge rib.

Claims (1)

[Claims] 1. A blower comprising an electric motor driven by a power source whose rotation speed is variably set, and a fan mounted and fixed to the rotary shaft of the electric motor, wherein the fan is directly mounted on the rotary shaft of the electric motor. A cylindrical boss portion, a cylindrical hub portion integrally provided with a base end portion of a blade blade, which is located on the outer periphery of the boss portion with a gap and has an air-blowing action on the outer peripheral surface thereof, and these boss portions. From a plurality of bridge ribs that are provided between the outer peripheral surface and the inner peripheral surface of the hub portion, two sets are provided along the axial direction, and the positions of the bridge ribs are displaced along the circumferential direction so as to oppose each other between the pitches. Blower characterized by becoming.