JPH0680318B2 - Multi-plate blower - Google Patents

Description

The present invention relates to a multi-plate blower.

(Prior Art) A so-called multi-plate type blower using a fan rotor by arranging a plurality of annular rotary disks having an opening at the center thereof on the same axis while maintaining a predetermined interval (minute interval), Known from the past (eg "Journal of Fluids Engineer
ing ”MARCH 1987. Vol P51-57).

In such a multi-plate type blower, as shown in FIG. 6, when a fan rotor 30 composed of a plurality of annular discs 20, 20, ... The fluid F between the discs 20, 20 ... Is rotated together with being dragged by the shearing force acting between the discs 20 and 20 and acting on the disc 20 surface, and gradually caused by the action of the centrifugal force. It flows outward in the radial direction and is discharged from the outer periphery of the fan rotor 30. Then, by repeating this continuously, the air blowing function is fulfilled.

(Problems to be Solved by the Invention) However, in the case of the conventional general multi-plate type blower, for example, the plurality of annular discs are enlarged as shown in FIG.
The end face (edge) 20a on the suction port side of 20, 20 ... Is flat, and the suction streamline of the intake air flowing in from the grill 32 side shown in FIG. 6 (see arrow in FIG. 7). First, it acts as a collision surface. Therefore, collision loss of air flow velocity energy occurs at the end face portion 20a of the disk. Further, since the end surface portion 20a has a predetermined angle with respect to the inflow direction of the air, flow separation occurs at the end surface portion (edge portion) 20a, and the viscous friction coefficient decreases. Further, as a result, for example, a pressure difference (Pa> Pb) occurs between the portions a and b in FIG. 7, the edge portion becomes a shape resistance, and pressure loss is generated also from this point, and the blowing ability is reduced. There is a problem of decline.

In addition, as described above, when the airflow is separated, Karman vortices are easily generated, and there is a problem that noise is generally generated.

(Means for Solving Problems) The multi-plate blower of the present invention has been made for the purpose of solving the above problems. For example, as shown in FIG. 1 to FIG. In the multi-plate blower 2 in which a plurality of annular rotating disks 8, 8 ... Having an opening 7 in the central portion are arranged side by side on the same axis at a predetermined minute interval, The inner peripheral surface portion 8a of the plates 8, 8 ... On the side of the aperture is curved along the direction of the air intake streamline.

(Operation) In the configuration of the present invention described above, the inner peripheral surface portion 8a side of the plurality of annular rotating disks 8, 8 ... Having the opening 7 in the central portion is provided with a predetermined amount along the air intake streamline direction. By curving with the characteristics of (1), air separation is prevented and the shape resistance is reduced.

Therefore, in the case of this configuration, it is possible to prevent the center hole opening side inner peripheral surface portion 8a of the disk 8 from colliding with the intake air flow sucked from the grill 10 direction of the blower main body, and as a shape resistance. Also becomes less effective.

As a result, the separation of the airflow is less likely to occur, and as a result, the Karman vortex is eliminated and noise is less likely to occur.

(Effects of the Invention) Therefore, according to the configuration of the present invention, it is possible to provide a multi-plate blower that can suppress pressure loss of the blower to a minimum and that is highly efficient, has a large capacity, and is highly quiet. .

<Examples> Hereinafter, two examples of the present invention will be described in detail with reference to the accompanying drawings.

(First Embodiment) First, FIGS. 1 to 4 show a multi-plate blower according to a first embodiment of the present invention.

Reference numeral 1 in the drawing denotes a casing portion of a ceiling-embedded air conditioner main body 3 incorporating the multi-plate blower 2 of the embodiment, which is located in the lower surface of the central portion of the casing portion 1. The multi-plate blower 2 is suspended via a drive motor 4. The multi-plate blower 2 has a circular main plate 5 fitted and fixed to the drive shaft 4a of the motor 4 and rotationally driven in the horizontal plane direction.
A connecting strut 6 located nearer to the outer periphery of the main plate 5, and central portions that are fitted and supported with respect to the connecting strut 6 and are arranged side by side at a predetermined minute interval from each other. It is composed of a plurality of annular discs 8 and 8 each having an opening 7 in its front end side (lower end side) facing the air suction port 11 on the grill 10 side. .

Therefore, by the motor 4, the plurality of disks 8,8 ...
When is rotated in the horizontal direction, the air F, which is a viscous fluid located in the space between the air intake 11 of the grill 10 and the disks 8, 8, ... It will be rotated by being dragged by the shearing force acting between. Then, due to the action of the centrifugal force generated as a result, the air F is caused to flow outward in the radial direction of the discs 8, 8 ... And discharged from the outer periphery of the discs 8, 8. Performs a blast function.

On the other hand, in this case, if the inner peripheral surface side edge portions 8a, 8a ... Of the plurality of discs 8, 8 ... The end face portion of the edge portion 8a acts as a collision surface of a predetermined area with respect to the air flow that flows in between the discs from the 11th direction, and collision loss occurs and the shape resistance increases and the air flow is increased. A pressure difference is generated between the front surface side and the rear surface side (the rear surface side becomes negative pressure), the flow is separated on the rear surface side (the upper surface side of the disc), and Karman vortices are generated, which causes noise (Fig. 7 above). reference).

Therefore, the respective disks 8, 8 ... In the present embodiment are configured such that the edge portions 8a, 8a ... Are curved along the air suction streamline (see the arrow in FIG. 2) from the grill opening 11. The edge portion 8a is machined as shown in the figure to have a structure having a maximum oblique inclination angle with respect to the thickness of the disk, thereby reducing the collision surface as in the conventional structure. Therefore, the air flow that flows in as shown by the arrow in FIG. 2 along with the rotation of the fan rotor having the above-described structure is almost lost at the inner peripheral surface side edge portion 8a of each of the disks 8, 8 ... Is divided into upper and lower parts, and smoothly flows outward in the radial direction according to the centrifugal force that acts on the curved surface without separating the flow and generating Karman vortices. As a result, as the blast loss generated in the disk portion, the friction loss of fluid generated in the curved surface portion and the collision formed by the curved surface of the disks 8, 8 ... With respect to the bending characteristic of the air suction streamline. Only a small collision loss corresponding to the angle θ (sin θ) can be achieved, and it becomes possible to considerably improve the blowing capacity as compared with the conventional disc structure shown in FIG. 7 (see FIG. 3). In addition, because there is no Karman vortex,
As is clear from the figure, noise is reduced and quietness is improved. Generally, in a so-called moving blade type turbo fan that uses blades (blades) or vanes (blades), the movement of the moving blades causes periodic pressure fluctuations in the space, for example, (number of moving blades Pn) × ( Rotational speed Nrpm) generates noise containing harmonics of frequency components equal to the rotational speed Nrpm, which is offensive to the ears, but in the case of the multi-plate blower targeted by this embodiment, structurally such a pressure fluctuation does not originally occur. Therefore, it has the feature that quiet rotation can be realized. Therefore, according to the structure of the present embodiment, the feature can be utilized more effectively,
Along with the reduction of the air loss, it is possible to further increase the air volume.

Then, the air flow from the multi-plate blower 2 configured as described above is blown out from the blowout port 13 of the air conditioner main body 3 after heat exchange via the heat exchanger 9 provided on the outer periphery thereof. It

(Second Embodiment) In the first embodiment, a plurality of discs 8 constituting the blower unit,
The diameter of 8 ... and the diameter of the central opening 7 are all equal, but in the case of the diameters of the above disks 8, 8 ..., For example, as shown in FIG. By gradually decreasing the diameter of the aperture 7 toward the side, the circular plate 8
It is also possible to increase the diameter of the friction surface portion.

If such a configuration is adopted, the air intake port between the discs from the lower end side to the upper end side is effectively opened in the direction of the grill 10, so that the ventilation efficiency is further improved and at the same time the upper side is improved. Since the centrifugal force generated on the disk becomes large, it is possible to substantially raise the blowing head.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing a configuration of a multi-plate type blower according to a first embodiment of the present invention in a state of being incorporated into an air conditioner body, and FIG. 2 is the same multi-plate type blower. FIG. 3 is an enlarged cross-sectional view of the main part of the blower, FIG. 3 is a characteristic diagram showing the blowing performance of the multi-plate blower of the same embodiment as compared with the case of the conventional example, and FIG. 4 is a diagram showing the sound generated from the blower. FIG. 5 is a graph showing the sound pressure-air volume characteristics in comparison with the conventional example, FIG. 5 is a sectional view of the multi-plate blower according to the second embodiment of the present invention in the same state as FIG. 1, and FIG. FIG. 7 is a cross-sectional view showing the structure of a conventional multi-plate blower, and FIG. 7 is an enlarged cross-sectional view showing the operation of the essential parts of the conventional structure. 1 …… Casing part 2 …… Multi-plate blower 3 …… Air conditioner body 4 …… Motor 5 …… Main plate 6 …… Coupling support 7 …… Opening 8 …… Disc 8a …… Edge part 10 …… Grill 11 …… Air inlet

Claims (1)

[Claims] 1. A plurality of annular rotating disks (8), (8), ... Having an opening (7) in the center thereof are arranged side by side on the same axis with a predetermined minute interval. The multi-plate blower (2) is characterized in that the opening side inner peripheral surface portion (8a) of each of the rotating disks (8), (8) is curved along the air intake streamline direction. Plate type blower.