JPH0787706A - Blower motor and starting method therefor - Google Patents

Abstract

PURPOSE:To obtain a low-cost blower motor having large air flow rate, high static pressure and low noise. CONSTITUTION:A turbo-fan 24 is mounted in one opening of a housing 21, and motor 31 having a heat-resistant winding is mounted on the other opening. The shaft 32 of the motor 31 is coupled to a drive shaft 28 of the fan through a mechanism 29 for multiplying the number of revolutions of the motor 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower motor used for a hand dryer and the like and a starting method thereof.

[0002]

2. Description of the Related Art A hand dryer is installed in a washroom or the like to dry wet hands after washing with warm air. Since this hand dryer has a structure that blows out a large amount of warm air at high speed in a short time and needs to be small, a blower motor in which a fan and a motor are integrated is used.

FIG. 2 shows a conventional blower motor used for such a hand dryer.
Reference numeral 1 in the drawing is a metal housing. The housing 1 has a substantially cylindrical shape, and a lid-shaped intake panel 2 is attached to one opening end of the housing 1. An intake hole 3 is formed in the center of the intake panel 2 so that outside air can be taken in through the intake hole 3.

A turbo fan 4 is provided inside the intake panel 2, and the turbo fan 4 has a diameter of 80 to 80.
It is 120 mm, and the rotation speed is 22000 to 2500.
Those that rotate at 0 rpm are used. A circular straightening plate 5 is attached inside the turbofan 4. The current plate 5 is for adjusting the flow of high-speed air generated by the turbofan 4 so that the air flows in the direction of the motor, which will be described later.

A motor 7 is provided so as to face the exhaust port 6 at the other open end of the housing 1. An inverter motor that rotates at a rotation speed of 20000 to 25000 rpm is used as the motor 7. Further, the rotation shaft 8 of the motor 7 is directly connected to the drive shaft 9 of the turbo fan 4 so as to rotate the turbo fan 4 at a high speed. Further, the outer case 10 of the motor 7 has a ventilation hole 1 for ventilation.
A large number of 1 ...

In such a blower motor, the turbofan 4 is driven by rotating the motor 7 so that the outside air is sucked into the housing 1 through the intake holes 3. This air flows to the motor 7 via the straightening vane 5. In the motor 7, a part of the electric power becomes heat due to the rotation, and heat is generated.
This heat is cooled by the air flow, and the air flow becomes a warm air flow and is discharged from the exhaust port 6. Since a large air volume and a high static pressure airflow are required as described above, the turbofan 4 is rotated at 20000 to 25000 rpm by using an inverter motor capable of high-speed rotation as the motor 7.

However, in the blower motor having such a structure, the turbo fan is rotated at a high speed as described above to secure the required air volume and static pressure, and therefore the noise generated from the turbo fan is very large. There was a flaw. Further, as a motor, a DC brush motor or an expensive inverter motor has to be used to rotate a turbo fan at a high speed, and there is a drawback that the cost increases.

[0008]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to obtain a blower motor which has a large air volume, a large static pressure, a small noise, and a low cost.

[0009]

To solve this problem, a turbofan for sucking outside air is attached to one opening of the housing, and a motor having a heat-resistant winding is attached to face the other opening of the housing. This can be solved by a blower motor in which the rotating shaft of the motor and the driving shaft of the turbofan are connected via a speed increasing mechanism that speeds up the rotation speed of the motor.

The present invention will be described in detail below. Figure 1
Shows an example of the blower motor of the present invention. In the figure, reference numeral 21 is a metal housing having a structure in which a cylindrical body is bent in a crank shape, and an intake panel is provided at one opening end thereof. 22 is attached. Intake panel 2
Reference numeral 2 denotes a circular lid-shaped member which is detachably attached to an open end of a housing 21. An intake port 23 is formed in a central portion of the housing 21, and outside air is supplied from the intake port 23 to the housing. It is designed to be captured in 1.

A turbo fan 2 is provided inside the intake panel 22.
4 are provided. The turbo fan 24 has a diameter of about 50 to 250 mm and a rotational speed of 2500 to 200 mm.
A thin fan blade that rotates at 00 rpm and has a short axial length of the fan blade is used. Also, 2
It may be a multi-stage type having more than one stage. Turbo fan 2
A disk-shaped straightening plate 25, which regulates the flow of air sucked by the turbofan 24 and flows toward the other open end of the housing 21, is attached to the inside of the housing 4. A through hole 26 is formed at the center of the current plate 25, and a drive shaft 28 of the turbo fan 24 having an idler 27 inserted therein is penetrated and loosely fitted in the through hole 26. The drive shaft 28 is directly connected to the secondary shaft 30 of the speed increasing mechanism 29.

The speed increasing mechanism 29 includes a primary shaft 33 directly connected to a rotary shaft 32 of a motor 31 described later, a primary timing pulley 34 coaxially attached to the primary shaft 33, and a primary timing pulley 34.
Secondary shaft 30 directly connected to drive shaft 28 of turbo fan 24
And a secondary timing pulley 35 coaxially attached to the secondary shaft 30 and a timing belt 36 made of synthetic rubber suspended between the primary and secondary timing pulleys 34, 35. And the secondary shaft 30
Are supported by bearings 37, 37 and fixed to the housing 21 via a bearing mounting plate 38. The number of teeth of the primary timing pulley 34 is about 1 to 6 times the number of teeth of the secondary timing pulley 35, and the number of teeth is about 1 to 6 times the number of rotations of the primary shaft 33. The secondary shaft 30 is adapted to rotate.

A usual AC induction motor, such as a bear motor or a condenser motor, is used as the motor 31, and its stator winding is heat resistant winding, that is, heat resistant insulated electric wire excellent in heat resistance. It is necessary to use the turned one. As such a heat-resistant insulated wire, a wire made of a ceramic coating as an insulating coating and a conductor preferably made of a conductive material having good heat resistance is used.
A material is selected which has a characteristic of withstanding use for 20,000 hours or more at 50 to 400 ° C.

Specifically, nickel plated copper, copper clad steel, nickel, stainless steel clad copper, nickel clad copper, gold, platinum, silver-copper alloy, etc. are used as the conductor, and alumina, as the ceramic coating. A ceramic powder such as magnesia mixed with a thermosetting resin such as methyl silicone or methylphenyl silicone is applied to a conductor, and a heat resistant resin coating such as polyimide enamel is further applied and baked on the conductor. In addition, the conductor has a conductivity (IACS) of 6
It is also possible to use about 0 to 95%, and it is possible to make it easy for a part of the current flowing through the conductor to be converted into heat.

The motor 31 has a rotation speed of 2500.
The starting torque is 0.5kg in the range of up to 3500 rpm.
cm or more is used. In particular, in the present invention, it is desirable that the starting torque is 2 kg · cm or more, which allows the turbo fan 24 having a large diameter of 50 to 250 mm to be used.
Can be driven. Further, in the cylindrical outer casing 39 of the motor 31, a large number of vent holes 40 are formed to dissipate heat generated from the motor winding through the air blown into the housing 21 by the turbofan 24.

Further, in this example, the outer case 39 of the motor 31 is attached so as to be almost in contact with the housing 21, so that the air flow flows through the inside of the motor 31.
Further, the end of the motor 31 on the side where the rotation shaft is not taken out is attached to the casing 21 such that its position is determined so as to face the exhaust port 41 at the other opening end of the casing 21. Further, in the blower motor of this example, the speed increasing mechanism 29
The rotary shaft 32 of the motor 31 and the drive shaft 2 of the turbofan 24
8 is eccentric, and the turbo fan 24 is moved to the side of the motor 31.

In such a blower motor, the rotation of the motor 31 at 2500 to 3500 rpm causes the speed increasing mechanism 2 to rotate.
The speed is increased 1 to 6 times by 9 and transmitted to the drive shaft 28 of the turbo fan 24, and the turbo fan 24 is rotated to 2500 to 2
Rotate at a rotation speed of 0000 rpm. The air taken in by the rotation of the turbo fan 24 has its airflow direction adjusted by the flow rectifying plate 25, and flows through the housing 21 toward the motor 31 side. The motor 31 inevitably generates heat from its winding as the motor 31 rotates, but this heat is transmitted to the air passing through it, and the air is heated and blown out from the exhaust port 41 to the outside.

In this example, the turbo fan 24 having a larger diameter than that of the conventional blower motor is used and driven by the motor 31 which generates a high torque, so that the air volume of the blown air becomes large and the static pressure is increased. Will also be expensive. Further, the rotation speed of the turbo fan 24 is set to 2500 to 20.
Since the speed is 000 rpm, which is about 10 to 90% of that of the conventional one, the noise generated from this is extremely low.
Moreover, since the turbo fan 24 has a large diameter,
The static pressure never drops. Therefore, with this blower motor, for example, an air flow of 1.5 to 2.5 m ³ / min and a static pressure of 10
00-1200 mm water column, noise level (A) 65-70
It is possible to have a characteristic of dB.

Further, since a high torque is generated in the motor 31, a large current flows through the winding and heat generation from the winding increases, but the heat resistance of the winding is excellent as described above. Since it is composed of an insulated wire and the winding is cooled by a large amount of air, the winding is not thermally deteriorated at all.
Moreover, the discharged air is cooled by 30 to 5 by cooling the winding.
Since it is heated to 0 ° C, it is convenient for applications such as a hand dryer.

Further, since the current capacity of the winding of the motor 31 is large and a large current can be passed at the time of starting, it can be rotated with a high torque immediately after starting, has a good start-up, and has a large air flow immediately after starting. Air can be sent with high static pressure. Further, since the structure of the motor 31 itself is the same as that of the conventional induction motor, the motor 31 can be less expensive than the conventional inverter motor.

The blower motor of the present invention is normally started by supplying a commercial alternating current as described above. However, when a high blown air temperature is required immediately after the power is turned on, the following is performed. Various starting methods can be adopted.
That is, a direct current is supplied to the winding of the motor 31 for a short time to preheat the winding with a direct current, before the alternating current is supplied to the motor 31 to start it. For example, voltage 50 to 70 V, current 10
After a direct current of up to 20 A is passed for 3 to 5 seconds, the direct current is cut off and an alternating current is passed. In the case of using a capacitor motor as the motor 31, the starting capacitor may be separated from the starting circuit by a switch, an alternating current may be supplied for a short time to preheat, and then the starting capacitor may be restored to rotate the motor. . Also, in the bear motor, the switch may be switched to change the polarity of the coil to stop the rotation, and in this state, the alternating current may be supplied for a short time, and then the switch may be switched to rotate.

In this method, since the air from the turbofan 24 is sent to the place where the winding is heated by direct current or alternating current, hot air of a considerable temperature is blown from the exhaust port 41 immediately after the application of the alternating current, and the hand is blown. When used in a dryer, the drying time can be shortened. Then, such a starting method can be realized only by using the heat-resistant winding as the winding of the motor 31, and the winding is instantaneously burned in the motor using the ordinary magnet wire.

In the blower motor of the present invention,
As the motor, Japanese Patent Application Nos. 4-44957 and 4
It is also possible to use the heat generation motor proposed in No. -21017. In this motor, a heat-resistant insulated wire in which a ceramic insulating coating is provided on a conductor having a conductivity of 5 to 95% is wound in a flat plate shape by air core winding and fixed to form a coil, and insulating layers are formed on both side surfaces of the coil. The coil element obtained by pressing the heat radiation plate through is used as the stator winding. By using this motor, the amount of heat generated from the winding becomes larger than that in the previous example, and the temperature of the air blown out becomes considerably high.

Further, in the blower motor of the present invention, an example in which a timing belt is used as the speed-up mechanism has been shown, but the invention is not limited to this, one using a plastic gear, a torque converter using a fluid, and a V-belt. Although it is possible to use the one using, it is preferable that the noise generated from the speed increasing mechanism is as small as possible.

(Embodiment) A turbo fan having a diameter of 150
An AC induction capacitor motor having an input of 750 W and a no-load rotation speed of 2900 rpm was used as the motor. For the stator winding of this motor, a ceramic insulated electric wire in which a ceramic insulating coating was formed on a nickel-plated copper wire having a diameter of 1.0 mm was used. The ceramic insulating coating was formed by applying a dispersion of alumina and magnesia in a methylphenyl silicone resin solution, applying a polyimide coating on this, and baking. The speed increasing mechanism has a speed increasing ratio of 4 times using a timing belt as shown in FIG.

AC 100V, 50H is applied to this blower motor
When a current of z is passed, the rotation speed of the turbofan reaches 9000 to 9200 rpm in 5 to 6 seconds after the start of energization, the air flow rate is 1.9 to 2.1 m ³ / min, and the static pressure is 1000 to 1200 m.
The temperature was around 45 ° C. in the vicinity of the air outlet, and the noise level (A) was 63 to 65 dB.

[0027]

As described above, in the blower motor of the present invention, since the motor provided with the heat-resistant winding is used, it becomes possible to flow a large current and generate a high torque, and thus a large torque can be generated. A caliber turbofan can be rotated. Further, since a turbo fan having a large diameter can be used, even if the turbo fan is rotated at a low speed, the air volume and static pressure do not decrease, and noise is conversely greatly reduced. Therefore, according to this blower motor, a large air volume and a high static pressure are obtained, and the noise is low. Furthermore, it is possible to send a large amount of air at a high static pressure immediately after starting. Moreover, since the motor structure itself is a simple induction motor, the cost of the motor can be kept low.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of a blower motor of the present invention.

FIG. 2 is a schematic configuration diagram showing an example of a conventional blower motor.

[Explanation of symbols]

21 ... Housing, 24 ... Turbo fan, 29 ... Speed increasing mechanism, 3
1 ... Motor.

Claims (2)

[Claims] 1. A turbofan for sucking outside air is attached to one opening of the housing, and a motor having a heat-resistant winding is attached to face another opening of the housing, and a rotary shaft of the motor is provided. A blower motor, wherein the drive shaft of the turbofan is connected via a speed increasing mechanism that increases the rotational speed of the motor. 2. A method for starting a blower motor according to claim 1, wherein before the blower motor according to claim 1 is started, a direct current or an alternating current is applied to the heat-resistant winding of the motor for a short time in advance and then the blower motor is started.