JPH04129898U - multi-winged fan - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a multi-blade fan with low noise, large discharge amount and/or high discharge pressure. [Structure] In a multi-blade fan 1 in which a blade wheel 2 is housed in a casing 3 having a curved flow path 10, the back side of the tip of the curved wall 13 on the inner peripheral side of the flow path 10 is covered with a partition plate 24. It is closed to form a ventilation chamber 25 extending in the longitudinal direction of the impeller 2. Ventilation holes 26 and 27 communicating with the ventilation chamber 25 are provided in parallel at the suction port side wall 21 and discharge port side wall 22 portions of the bent wall 13 surrounding the ventilation chamber 25, and the tip wall 23 is provided as necessary.
Ventilation holes 28 are also provided in parallel.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to a multi-blade fan used to blow gas such as air or gas.

0002

[Conventional technology]

Generally, it is made by arranging long and narrow blades that are concavely curved with respect to the rotation direction on the circumference. The impeller is inserted into the casing across the curved flow path from the suction port to the discharge port. A rotatably supported multi-blade fan can produce a wide belt-shaped discharge flow. It came to be widely used in air conditioning equipment and other applications.

0003

[Problem that the idea aims to solve]

However, among the multi-blade fans mentioned above, large multi-blade fans with large discharge volume and discharge pressure When designing and producing a Reduce the gap between the facing wall of the casing and the blade (gap 20 in Figure 2). This causes a siren-like noise, and when the gap is increased, the The flow rate of gas flowing back from the discharge port side to the suction port side increases, resulting in a decrease in the discharge volume and pressure. It has been difficult to obtain large, low-noise multi-blade fans.

0004 This idea solves the above-mentioned problems of the conventional methods, and allows the discharge of air without increasing noise. Let us provide a multi-blade fan that can increase output volume and/or discharge pressure. That is.

[0005]

[Means to solve the problem]

This multi-blade fan uses circular blades that are curved concavely in the direction of rotation. The impellers, which are arranged in parallel on the circumference, cross the curved flow path from the suction port to the discharge port. , in a multi-blade fan rotatably supported in a casing, the curved flow path is The back side of the tip of the bent wall forming the inner circumferential wall surface is closed with a partition plate, and the longitudinal direction of the impeller is closed. forming a ventilation chamber extending in the direction, and at least a suction portion of the bent wall surrounding the ventilation chamber; A feature is that ventilation holes communicating with the ventilation chamber are arranged in parallel on the mouth side wall and the discharge port side wall. shall be.

[0006]

[Effect]

In the multi-blade fan of this invention, as the impeller rotates, the area near the tip of the bending wall A part of the air discharged by the impeller enters the ventilation chamber from the ventilation hole on the side wall of the discharge port. It flows in, flows out to the suction port side through the ventilation hole on the side wall of the suction port, flows into the impeller again, and is discharged. A vortex that circulates toward the mouth side is generated along the entire length of the impeller. This vortex is bent The gap between the tip of the wall and the impeller is sealed like an air curtain. The flow rate of gas flowing back from the discharge port side to the suction port side through the pump is reduced.

[0007]

【Example】

An embodiment of this invention will be described below with reference to FIGS. 1 to 3. In the figure, 1 is a multi-wing faucet. It consists of a blade wheel 2 and a casing 3 that rotatably supports the blade wheel. The wing wheel 2 is , an elongated blade 4 having a cross section concavely curved with respect to the direction of rotation is placed on the circumference. A large number of plates are arranged side by side, their ends are fixed to disks 5a and 5b, and the Each of them has supporting shafts 6a and 6b protruding from each other. 7 is a circle connecting the blades 4 at the middle part It is a plate-shaped reinforcing plate.

[0008] The casing 3 also has a rectangular suction port 11 extending in the longitudinal direction of the impeller 2, and a rectangular suction port 11 extending in the longitudinal direction of the impeller 2. It has a curved flow path 10 leading to a rectangular discharge port 12 that opens in a plane perpendicular to the A bent wall 13 forming an inner circumferential wall surface of the flow path 10 and a bent wall 14 forming an outer circumferential wall surface. Both ends are fixed to side plates 15a and 15b. The impeller 2 crosses the flow path 10 The bearing 16a is housed in the casing 3 and attached to the side plate 15a, and the side plate 1 The support shafts 6a and 6b are rotatably supported by bearings 16b attached to the shafts 5b. held. 17 is a pulley attached to the support shaft 16b, which is driven by an electric motor (not shown). This is for driving the impeller 2 with a belt.

[0009] Further, the bent wall 13 forms a part of the suction port 11, as shown in FIGS. 2 and 3. a suction port side wall 21 forming a part of the discharge port 12; and a discharge port side wall 22 forming a part of the discharge port 12; The tips of the side walls are connected and faced to the outer periphery of the impeller 2 with a small gap 20. It consists of a bent plate having a tip wall 23. 24 is a partition made of a plate having the same length as the bending wall 13; The wall plate is fixed to the back side of the bending wall 13, and is attached to the tip of the bending wall 13 (closer to the tip wall 23). ) is closed to form a ventilation chamber 25 extending in the longitudinal direction of the impeller 2. Then, the suction port side wall 21 and the discharge port side wall 22 surrounding this ventilation chamber 25, and the tip In a portion of the wall 23 near the suction port side wall 21, there are ventilation holes 26, 2 that communicate with the ventilation chamber 25. 7 and 28 are arranged in parallel over the entire length of the bending wall 13.

0010 In the multi-blade fan 1 having the above configuration, when the impeller 2 is rotated by the motor, as shown in FIG. As shown in , since the pressure on the discharge port 12 side is higher than that on the suction port 11, the discharge gas (air) A part of the air (air and gas) flows into the ventilation chamber 25 from the ventilation hole 27 and flows into the ventilation hole 26 and 2. It flows out from 8. As a result, the tip of the bending wall 13 and the impeller 2 passing around this area A vortex 30 of gas flow circulating between the The large amount of gas that has been introduced curves through the outside of this vortex 30 and passes inside the impeller 2, The tip of the bent wall 13, specifically, the discharge port side wall 22 near the tip wall 23, is hit at high speed. It flows out from the discharge port 12 without hitting. Then, the vortex 30 fills the gap 20 with air. -Since it seals in a tens shape, high discharge pressure can be obtained without reducing the clearance 20. It is possible to reduce the noise, and from the discharge port side through the gap 20. Since the amount of gas flowing back to the suction port side is small, it is easy to obtain a multi-blade fan with a large discharge volume. It is possible.

[0011] Also, depending on the volume of the ventilation chamber 25 and the opening area and number of the ventilation holes 26 to 28, Therefore, the ventilation chamber 25 can also function as a muffler, further reducing noise. You can find out.

0012 This invention is not limited to the above embodiments, but for example, the capacity of a multi-blade fan. Depending on the shape of the curved wall 13, etc., the ventilation hole 28 formed in the tip wall 23 may be omitted. good. This idea can also be applied to multi-blade fans that are integrated with a motor. .

[0013]

[Effect of the idea]

As explained above, according to this invention, the gas formed between the ventilation chamber and the impeller The vortex causes the air to flow from the discharge port side to the suction port side through the gap between the tip of the curved wall and the outer periphery of the impeller. Since the flow rate of gas flowing back to the It is possible to increase the amount and discharge pressure, and also prevents the occurrence of loud noise due to insufficient clearance. This makes it easy to design and manufacture multi-blade fans with low noise, large flow rate, and/or high discharge pressure. Become.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a multi-blade fan showing an embodiment of this invention.

FIG. 2 is an enlarged sectional view taken along line A-A in FIG. 1;

FIG. 3 is a perspective view of the intermediate cut portion of the casing in FIG. 1;

[Explanation of symbols] 1 Multi-winged fan 2 Wing wheel 3 Casing 4 Feathers 10 Flow path 11 Suction port 12 Discharge port 13 Bent wall 21 Suction port side wall 22 Discharge port side wall 23 Tip wall 24 Partition plate 25 Ventilation room 26 Ventilation hole 27 Ventilation hole 28 Ventilation hole

Claims (1)

[Scope of utility model registration request] [Claim 1] An impeller consisting of long and thin blades curved concavely with respect to the rotational direction arranged side by side on the circumference is arranged in a casing so as to cross a curved flow path from the suction port to the discharge port. In a multi-blade fan rotatably supported inside the fan, the back side of the tip of the bent wall forming the inner circumferential wall surface of the bent flow path is closed with a partition plate to form a ventilation chamber extending in the longitudinal direction of the impeller. A multi-blade fan characterized in that ventilation holes communicating with the ventilation chamber are arranged in parallel at least in a suction port side wall and a discharge port side wall portion of the bent wall surrounding the ventilation chamber.