JP2010007902A - Ventilation fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein when a mounting member used for mounting a motor to a motor base has a small contact area with the motor and motor base, since release of heat generated in the motor to the motor base is deteriorated, the temperature of a motor bearing is raised, leading to decline in the service life of the motor bearing. <P>SOLUTION: An air blower portion comprising an air blowing fan connected to the motor by a motor shaft, a bell mouth having a suction port formed thereon and a scroll formed to surround the periphery of the air blowing fan and the motor to which the air blowing fan is connected are mounted to the motor base by the mounting member. In the mounting member, a contact area of a stator core of the motor with the mounting member and a contact area of the mounting member with the motor base are set larger than that of a bracket to which the motor bearing of the motor is inserted with the stator core. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a blower that is provided in home appliances such as an air conditioner and a ventilation fan, and sucks and discharges air, and particularly relates to a ventilation fan (small air volume type) that is used for 24-hour ventilation in order to prevent sick house in a general household.

As a typical example, this type of ventilation fan is often used for a two-story house with a total floor area of 40 tsubo (132 m ² ). The volume of the space that is subject to 24-hour ventilation excluding indentation and closet is 297.5m ³ if the target area is 119m ² and the ceiling height is 2.5m, and the required ventilation rate is 0.5 times / h. The total ventilation required for the first and second floors is approximately 150 m ³ / h.

  In addition, this type of ventilation fan is generally installed on the ceiling of the sanitary zones (spaces around the water with sanitary facilities such as toilets, bathrooms, and washrooms) on the 1st and 2nd floors. From the viewpoint of cost, construction cost, etc., a fan with a blade diameter of about 10 cm is often used.

In this case, the total of 150m ³ / h is required for the 1st and 2nd floors, so if 2 units / door are used, a ventilation volume of 75m ³ per unit is sufficient. Normally, when installing a ventilation fan, duct piping and an outdoor hood (not shown) are required, but each has ventilation resistance, so the performance required for the ventilation fan is about 100m in the open state (no ventilation resistance) ³ / h is required. Furthermore, the market price competition of this type of ventilation fan is intensifying, and a motor with a low price is often used for the motor.

  Generally, the scraping motor is inefficient compared to the capacitor run motor, and the stator windings of the motor generate a large amount of heat. Therefore, the bearing temperature of the motor increases due to heat conduction. If the motor bearing temperature rises, the life time of the bearing used as a bearing will be shortened, but by efficiently dissipating the heat generated from the stator winding of the motor, the temperature rise of the motor bearing will be reduced, The airflow can meet the required ventilation without reducing the life of the motor.

  Conventionally, what is shown in Unexamined-Japanese-Patent No. 2001-263754 (patent document 1) is known as a ceiling embedded type ventilation fan which can cool the motor provided inside.

  This ceiling-embedded ventilation fan is a ceiling-embedded ventilation fan in which a blower part provided with a sirocco fan surrounded by a scroll and a storage part in which a motor for driving the sirocco fan is partitioned are defined. Auxiliary blades are provided in the air, and the air in the storage portion in which the motor is stored is guided into the scroll by the auxiliary blades, and is combined with the air sucked into the scroll through the intake hole of the bell mouth and is discharged from the discharge port to the outside of the machine. On the other hand, the air in the scroll is caused to flow into a storage portion in which the motor is stored.

Thereby, the flow of the air exhausted through the scroll through the storage portion in which the motor is stored from inside the scroll can be formed, and the motor is cooled by this air flow.

However, since the air in the scroll is sent to the storage part in which the motor is stored, the dust and moisture contained in the air may promote the deterioration of insulation and rust of the motor, which may shorten the life of the motor. It was.

JP 2001-263754 A

  The object of the present invention has been made in view of the above problems, and increases the dissipation of heat generated from the motor, lowers the temperature of the bearings of the motor, and allows the motor to be driven by the flow of air containing dust and moisture. An object of the present invention is to provide a ventilation fan that can extend the bearing life of a motor of a blower without using cooling.

  In order to achieve the above object, the present invention is characterized in that a motor, a blower fan connected by the shaft of the motor, a bell mouth formed with a suction port, and a periphery of the blower fan are formed. The motor part connected to the blower fan and the fan connected to the motor base are attached to a motor base by an attachment member. The attachment member includes a stator iron core and an attachment member of the motor, and an attachment member and a motor base. The contact area is configured to be larger than the contact area between the bracket into which the motor bearing of the motor is inserted and the stator core.

  The ventilation fan according to the present invention uses an attachment member having a high thermal conductivity when the motor is attached to the motor base, and the heat generated in the stator winding of the motor is conducted to the motor base and dissipated through the attachment member. Thereby, the bearing temperature rise of a motor is reduced and the bearing life of a motor can be extended.

  Hereinafter, an embodiment of a ventilation fan according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a sectional view of a ventilation fan according to the present invention, and FIG. 2 is an explanatory view of motor mounting according to the present invention.

  The ventilation fan according to the present invention includes a sirocco fan 5 in which a blower portion is connected to a shaft of a motor 3, a scroll 1 formed so as to surround the periphery of the sirocco fan 5, and a bell mouth 7 formed with a suction port. The motor arrangement portion includes a motor 3, an attachment member 2 for attaching the motor 3, and a cover 4 for protecting the motor 3 from dust and the like. The motor base 8 to which the motor 3 is attached by the attachment member 2 is the above-described one. It has the role of the partition which divides | segments a fan part and a motor arrangement | positioning part.

  Furthermore, the air sucked from the bell mouth 7 in the blower portion is sent to the discharge port 1a by the sirocco fan 5 and discharged to the outdoors. Moreover, the joint part 1b is used for connection with duct piping (not shown).

  The structure of the motor 3 will be described with reference to FIG.

  In the motor 3, a stator winding 3a is attached to a stator core 3e, and this portion serves as a heat source. A shaft 3f is attached to the rotor 3d so as to pass therethrough, and bearings 3b are attached to the top and bottom of the rotor 3d. The bearing 3b is fixed by a bracket 3c, and the rotor 3d is rotatably installed by this configuration.

  The material of the stator core 3e is a silicon steel plate, and the bracket 3c is a zinc alloy (die-cast), both of which are metals.

  As described above, the stator winding 3a is a heat source. The heat generated here is conducted to the bearing 3b through the stator core 3e and the bracket 3c.

  The motor 3 is conventionally mounted by a mounting member 20 (see FIG. 3), and this material often uses brass, and the mounting area is small, and no special consideration has been given to heat dissipation. Therefore, as described above, the heat generated in the stator winding 3a is transmitted to the bearing 3b.

  In the present invention, a large mounting area is used as in the mounting member 2 (see FIG. 2), and a material with good thermal conductivity is used.

  Thus, the heat generated in the stator winding 3a is transmitted to the motor base 8 through the mounting member 2 before being transmitted to the bearing 3b, and heat conduction to the bearing 3b can be reduced.

  As shown in FIG. 2, the attachment member 2 is formed with a screw hole 2a for engaging the motor 3 and the motor base 8, and a screw hole 2b for engaging the motor 3. The attachment screw 2 is attached via the screw hole 2a. 9 is fastened to the motor base 8. Further, the mounting member 2 is fastened to the motor 3 with a mounting screw 10 through the screw holes 2a and 2b.

  In the embodiment of the present invention shown in FIGS. 1 and 2, the mounting member 2 is made of aluminum.

  Here, the attachment member 2 may be formed of an integral type such as zinc. According to this embodiment shown in FIG. 6, the attachment portion with the motor base 8 is connected to the bracket 3c by the bridging portion 21f and formed integrally. The cross-sectional area of the bridging portion 21f is formed smaller than the area 21e of the portion in contact with the motor base.

  Table 1 shows a comparison between the typical examples of materials having good thermal conductivity and the ease of heat transfer.

The heat conductivity of each material is transferred from the high temperature 2c side (20c side for conventional products) to the low temperature 2d side (20d side for conventional products) when there is a temperature difference in the mounting member. A phenomenon occurs. When there is a temperature difference of 1 degree per unit length (thickness) on both surfaces of the mounting member, the amount of heat transferred to 1 hour per 1 m ² is expressed as thermal conductivity. The greater the value of this thermal conductivity, the greater the amount of heat that moves and the easier the heat is transferred.

  The order of good heat conduction is copper> aluminum> zinc, but in the present invention, aluminum is selected from the material cost, workability and the like. If the heat quantity ΔQ flows from the high temperature 2c side (20c side for the conventional product) to the low temperature 2d side (20d side for the conventional product) during the time Δt, the heat flow rate ΔQ / Δt is It is proportional to the mounting area and temperature difference of the mounting member, and inversely proportional to the thickness.

  Rewriting the above equation using thermal conductivity yields:

  When comparing the (area 2e) / (thickness) of the mounting member 2 used in the present invention with the area 20e) / (thickness) of the conventional mounting member 20,

  Here, the mounting area is in the order of the product of the present invention> contact area between the bracket and the stator core (the conventional product and the product of the present invention are the same)> the thickness of the mounting member (the product of the present invention). ) = (Conventional product).

  Compared with the same material (aluminum) and thermal conductivity of aluminum: 240 (W / m · K) at 100 ° C with a temperature difference of 1 degree, the conventional product: 0.45 (W) In contrast, the present invention is 4.38 (W). Therefore, it can be seen that the mounting member 2 of the present invention has better heat dissipation performance.

  The measured temperature values of the conventional product and the motor bearing according to the present invention are as shown in FIG.

  30a is the conventional product, and 30b is the temperature of the bearing in the present invention. 40 is the temperature at the time of measurement.

  The temperature before the ventilation fan operation is almost the same as the air temperature, but the temperature rises at the same time as the operation starts. In about 2 hours, heat generation and heat dissipation are balanced and an equilibrium state is reached. The temperature difference at this time was about 15 ° C.

  Here, an example is given and demonstrated. In the present invention, the bearing 3b of the motor 3 is formed of a sealed ball bearing. The life of the general-purpose grease sealed in the bearing 3b is expressed by the following equation.

ｔ：平均グリース寿命（ｈ）
ｎ：軸受の回転速度(min^-1)……本発明の事例では、約１,０００回転
Ｎmax：グリース潤滑の許容回転数(min^-1)……本発明の事例では、３２,０００回転
Ｔ：軸受の運転温度（℃）
ここで、本発明の実施例の換気扇では、

となるので

として計算する。

t: Average grease life (h)
n: Bearing rotational speed (min ⁻¹ ) …… In the example of the present invention, approximately 1,000 revolutions Nmax: Allowable rotational speed of grease lubrication (min ⁻¹ ) …… In the example of the present invention, 32,000 revolutions T : Bearing operating temperature (℃)
Here, in the ventilation fan of the embodiment of the present invention,

Because

Calculate as

  Now, assuming that the operating temperature T of the bearing when the conventional mounting member 20 is used is 70 (° C.), the average grease life t is 22,400 (h). The temperature when the mounting member 2 is used is 55 (° C.) as shown in FIG. The average grease life t at that time is 47,900 (h).

  Therefore, the ventilation fan according to the present invention can reduce the temperature of the bearing 3b of the motor and improve the grease life by improving the heat conduction from the motor 3 to the motor base 8 as compared with the conventional ventilation fan. be able to.

It is sectional drawing of the air blower which concerns on one Example of this invention. It is motor attachment explanatory drawing by this invention. It is conventional motor attachment explanatory drawing. It is a structural diagram of a motor. It is a temperature measurement graph of a bearing. It is a structural diagram at the time of making an attachment member and a bracket into an integrated type.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Scroll 1a Discharge port 1b Joint part 2,20 Mounting member 2a, 2b Screw hole 3 Motor 3a Stator winding 3b Sealed ball bearing 3c Bracket 3d Rotor 3e Stator iron core 3f Shaft 4 Cover 5 Sirocco fan 7 Bell mouth 8 Motor Base 9, 10 Mounting screw 21f Bridge 30a Conventional bearing temperature 30b Invention bearing temperature 40 Air temperature during measurement

Claims (3)

  A motor and a blower fan connected by a shaft of the motor, a bell mouth formed with a suction port, a blower part formed of a scroll formed so as to surround the blower fan, and the blower fan connected thereto The motor is attached to the motor base by an attachment member. The attachment member has a stator core of the motor and an attachment member, and a contact area between the attachment member and the motor base is fixed to the bracket in which the motor bearing of the motor is inserted. A ventilation fan characterized by being configured to be larger than the contact area with the core.   The ventilation fan according to claim 1, wherein the mounting member is made of a material having a high thermal conductivity.   The bracket in which the mounting member and the motor bearing are inserted is integrated, and the cross-sectional area of the bridge portion between the bracket and the mounting member is made smaller than the area of the portion where the mounting member contacts the motor base. The ventilation fan according to claim 1, characterized in that:

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