JPS61243234A - Ventilating fan - Google Patents

Abstract

PURPOSE:To provide a ventilating fan which has high ventilation rate and reduces the generation of noise and the occurence of a trouble, according to a method wherein the rotor of an induction electric motor is formed into a hollow cylinder body, and an impeller for blast is formed integrally with the inner side of the rotor. CONSTITUTION:The tips 2a of eight vanes 2a for blast are secured to the inner periphery of a rotor 1, and a root 2b is formed integrally with a boss 3. The vane 2 for blast is so shaped as to allow axial blast, and the eight vanes are disposed at equal intervals to form an impeller 4. A shaft 6 is secured to support rods 8 mounted to a frame body 7. The periphery of the rotor 1 is brought into frictional contact with a stator 11 with a given distance C set therebetween, and the stator is secured to the frame body 7 finished in a form that the frame body is easy to install. As noted above, most of the inner side of the frame body 7 of a ventilating fan can be used as a blast port, and this enables ventilation of a high volume by means of a relatively small blast port.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a ventilation fan.

(Prior Art) As is well known, conventionally used ventilation fans have a structure in which an impeller for blowing air is attached to the shaft of an electric motor and is fixed to a frame. In this case, the exhaust flow passes through a gap between the inside of the frame of the ventilation fan and the periphery of the electric motor provided in the center of the frame.

(Problem to be Solved by the Invention) In conventional ventilation fans, a large electric motor occupies the center of the ventilation hole where the flow velocity should normally be the highest, blocking the passage of exhaust air, resulting in a decrease in ventilation efficiency. Since the area through which the exhaust air can pass inevitably decreases, it is necessary to take measures such as increasing the flow velocity or expanding the ventilation holes. Furthermore, since the electric motor, structural materials to support it, wiring cords, etc. are installed in the center of the ventilation hole, the contact surface with the exhaust flow becomes large, which may cause noise (wind noise) due to fluid friction. This causes electrical system failure.

An object of the present invention is to provide a ventilation fan with a high ventilation rate and with less noise and failure by minimizing obstacles to the exhaust flow existing in the center of the ventilation hole.

(Means for Solving the Problems) Therefore, the present invention adopts the following means.The rotor 1 of the induction motor is formed into a hollow cylindrical body with predetermined dimensions, and air is blown inside the rotor. The impeller 4, which has a plurality of blades formed so as to be able to blow air in the axial direction, is constructed by integrating the impeller and the rotor.The base 2b of the blade 2 is pivotally supported on the shaft 6 of the rotor 1. It is integrated with a certain boss 3. A gap C necessary for rotation of the rotor is provided between the rotor 1 and the stator 11, and this stator is made up of a stator core 9 and a stator winding 10. The rotor 1 can be rotated by applying electricity to the stator.

(Function) When an AC power source is connected to the winding 10 of the stator core 9, an eddy current is generated on the circumferential surface of the rotor 1 due to electromagnetic induction, giving a rotational force to the rotor, causing it to rotate about the shaft 6. Therefore, the impeller 4 provided in the rotor 1 also rotates together with the rotor, and starts blowing air. At this time, the exhaust flow passes inside the rotor.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

The rotor 1 is made of aluminum or copper and is molded into a thin cylinder as shown in the first and second figures. The outer circumferential surface of the rotor 1 is provided with oblique narrow grooves 1a to prevent generation of abnormal torque.

Tips 2a of eight air blowing blades 2 are fixed to the inner periphery of the rotor 1, and the roots 2b are integrated with the boss 3. The air blowing blades 2 have a shape that allows air to be blown in the axial direction, and eight blades are arranged at equal intervals to form an impeller 4. A boss 3, which is a provision for the impeller 4, is supported on a shaft 6 together with oil-free bearings 5, 5. The shaft 6 is fixed to support rods 8, 8 which are attached to the frame 7.

A stator 11 made up of a stator core 9 and a stator winding 10 is in sliding contact with the rotor 1 at a predetermined interval C around the rotor 1, and the stator is finished in a shape that is easy to install. It is fixed to the frame body 7.

Next, the installation procedure of the present invention will be explained.

The frame body 7 is fixed in a predetermined position, and the mounting portion 7a formed by extending both sides of the frame body and the duct 12 are connected to a campus joint 13.
A cord (not shown) for supplying power to the stator winding 10 from the outside is wired.

Next, other embodiments will be described.

As shown in the third figure, the ventilation fan is constructed of a double pipe and is integrated with a sleeve 14, and the iron core 9 and the winding 1 forming the stator 11 are located between the outer pipe 14a and the inner pipe 14b.
0, and the rotor 1 and impeller 4 are fixedly installed inside the inner tube. The installation method in this case is to make a ventilation hole in the wall W that partitions the room to be ventilated and the outdoors, embed the sleeve S in advance into the frame, and insert the sleeve 21, which is integrated with the ventilation fan, into the hole. The power source for the stator 11 is taken from the wiring 15 inside the wall.

Maintenance and repair can be carried out by removing the entire sleeve 21 from the skeleton driving sleeve S, and then reattaching it.

(Effects of the Invention) According to the present invention, most of the inside of the frame of the ventilation fan can be used as an air outlet, so a large volume of ventilation can be achieved with a relatively small air outlet. Additionally, since there are fewer surfaces that come into contact with the fluid, there is less wind noise, allowing for quieter operation, and eliminating the need for a power cord inside the air outlet, which helps reduce electrical system failures.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the installed state, FIG. 2 is a perspective view of the rotor, and FIG. 3 is a sectional view showing the installed state in another embodiment. 1... Rotor, 2... Air blower, 4... Impeller. that's all

Claims (1)

[Claims] The rotor of an induction motor is composed of a hollow cylindrical body,
A ventilation fan characterized in that an impeller for blowing air is integrally formed inside the rotor.