JPS623639Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a ventilation fan, and aims to induce an airflow that cools the motor of the ventilation fan, and to prevent the contamination of the motor by preventing oil smoke particles from being included in the airflow that cools the motor. purpose.

Conventionally, as shown in FIG. 1, an impeller 103 having a bowl-shaped blade body 102 that covers approximately the front half of a motor 101 is tightened by a mounting body 104 that is screwed onto the rotor shaft. Although it was attached to the rotor shaft, the front half of the motor was covered by the blade body 102 of the impeller 103, which resulted in poor heat dissipation from the motor and shortened motor life. In addition, in the impeller of an electric fan, it has been considered to use ribs in the blade body to cool the motor by passing air through the blade body, but when used in a ventilation fan that exhausts contaminated air including oil smoke, etc. had the disadvantage that the motor was heavily contaminated and difficult to clean.

The present invention is intended to eliminate the above-mentioned conventional drawbacks, and embodiments thereof will be described below with reference to FIGS. 2 and 3.

In the figure, 1 is an outer frame of a ventilation fan that is fitted into a ventilation hole formed by a wooden frame 3 in a wall 2, 4 is a motor provided in the outer frame 1 by support legs 5, and 6a is a rotor of the motor 4. The threaded part 7 provided at the tip of the shaft 6 is an impeller having a bowl-shaped blade body 8 in the center that covers the front half of the motor 4, and the rotor shaft 6 is fitted into the center of the blade body 8. A boss portion 9 having a through hole 9a is provided. Reference numeral 10 indicates a plurality of ventilation holes provided outside the boss portion 9 on the front surface of the blade body 8;
Reference numeral 1 denotes a fixing screw that fixes the impeller 7 by screwing into a threaded portion 5 formed at the tip of the rotor shaft 6 protruding from the front part of the blade body 8, and its outer circumference is approximately the same as the outer diameter of the blade body 8. A protrusion 12 is formed to have the same diameter and is provided at the center to abut against the boss 9. The axial length of the protruding portion 12 is longer than the axial thickness of the main body portion 11a of the fixing screw 11 to form a spacer. Therefore, when installing the rotor shaft 6, the fixing screw 1
A gap 13 is created between the impeller 1 and the impeller 7. 12
A is a threaded part formed at the center of the fixing screw 11 so as to be threaded into the threaded part 5.

In the above configuration, the boss part 9 of the impeller 7 is inserted into the rotor shaft 6, the fixing screw 11 is screwed into the threaded part 6a of the rotor shaft 6, and the tip of the protruding part 12 of the fixing screw 11 is connected to the blade body. When tightened until it contacts the boss portion 9 of 8, the protruding portion 12 of the fixing screw 11 creates a gap 1 between the back surface of the fixing screw 11 and the front surface of the blade body 8.
3 is formed. When the impeller 7 is driven by the motor 4 in this state, air is attracted from inside the impeller body 8 by the air flow of the impeller 7, and the fixing screw 11
A gap 13 formed between the back surface of the blade body 8 and the front surface of the blade body 8
More air is sucked in, and an air flow path is formed that flows into the blade body 8 through the ventilation holes 10. The air flow cools the motor 4, improving heat dissipation from the motor 4, and reducing the temperature rise of the motor 4. It is something that will be done.

On the other hand, when using a ventilation fan to ventilate oily smoke generated from a microwave oven, etc., oily smoke particles have a higher specific gravity than air, so their penetrating force is large and they tend to move straight, so they join the axial airflow generated by the impeller 7. The motor 4 is less likely to be contaminated because the air flow that is ventilated and drawn in perpendicularly to the axial air flow contains fewer soot particles.

In this way, according to the present invention, air is drawn into the blade body to form an air flow that cools the motor, so even if the front half of the motor is covered by the blade body, heat dissipation from the motor is good. This reduces the temperature rise, and the airflow that cools the motor is sucked in from the direction perpendicular to the axial direction due to the void created by the spacer, which reduces the degree to which oil smoke particles are included in the airflow and cools the motor. This has the effect of reducing contamination.

Although the spacer has a simple structure by being formed integrally with the fixing screw, it may be formed separately using a member such as a washer.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional ventilation fan, FIG. 2 is a sectional view of a ventilation fan according to an embodiment of the present invention, and FIG. 3 is an enlarged sectional view of the same essential parts. 4...Motor, 6...Rotor shaft, 7...Impeller, 8...Blade body, 9...Boss portion, 9a...Through hole, 10...Vent hole, 11...Fixing screw, 12...
...Protrusion (spacer), 13...Void.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A motor having a bowl-shaped blade body having a boss portion in the center having a through hole into which the rotor shaft of the motor is fitted and covering the front half of the motor. an impeller, a plurality of ventilation holes provided on the front surface of the blade body, and an outer circumference having substantially the same diameter as the blade body;
A ventilation fan comprising a fixing screw having a threaded part formed in the center thereof to be threaded into the rotor shaft, and a spacer forming a gap between the impeller and the fixing screw. (2) The ventilation fan according to claim 1 of the utility model registration claim, characterized in that the spacer is integrally formed with the fixing screw.