CN1212479C - Vane of centrifugal blower and centrifugal blower with said vane - Google Patents

Abstract

The present invention provides an impeller allowing noise to be reduced and a low noise centrifugal blower, the multi-vane centrifugal blower (40) comprising mainly an impeller (63), a casing (11) covering the impeller (63), and a motor (14) rotating the impeller (43), wherein the impeller (43) is so formed that a plurality of blades (33) are fixed to the outer peripheral edge of a disk-like main plate (61) and the other ends of the plurality of blades are connected to each other through an annular side plate (62), the plurality of blades (33) are formed on the outer peripheral edge of the main plate (61) at equal intervals in rotating direction, an irregular waveform shape (64) is formed near the inner peripheral edge part of the plurality of blades (33) along the periphery of the inner peripheral edge part, and an irregular waveform (66) is formed on the surface of the side plate (62) on the main plate (61) side.

Description

Impeller of centrifugal blower and centrifugal blower provided with the impeller

technical field

The invention relates to a centrifugal fan impeller and a centrifugal fan equipped with the impeller, in particular to a centrifugal fan impeller in which the ends of a plurality of blades extending from a main board are connected by annular side plates and a centrifugal fan equipped with the impeller. Blower.

Background technique

In gas regulators such as gas purifiers and air conditioners (hereinafter referred to as air conditioners), air is blown using a centrifugal blower. As a conventional example, there is an example of a centrifugal blower called a multiblade blower shown in FIGS. 1 to 3 . Fig. 1 is a side view of a conventional multiblade blower; Fig. 2 is a perspective view of a conventional multiblade blower impeller; Fig. 3 is a plan view of a conventional multiblade blower impeller.

The multi-blade air blower 10 is composed of an impeller 13, a casing 11 covering the impeller 13, a motor 14 for rotating the impeller 13, etc. One end of a plurality of blades 33 of the impeller 13 is fixed on the outer peripheral edge of the disc main board 31, and the other end is fixed on the outer peripheral edge of the disc main board 31, and the other end is connected to the ring side. Board 32 is connected. The casing 11 is formed with an air outlet 11 a and an air inlet 11 b surrounded by the bell mouth 12 . The air inlet 11b is opposite to the side plate 32 of the impeller 13 . In addition, the air blowing port 11a is formed in a direction perpendicular to the air inlet 11b, so that the air blowing in a direction substantially perpendicular to the rotation axis O-O of the impeller 13 is ensured.

When the rotary motor 14 operates the multi-blade blower 10 , the impeller 13 rotates relative to the housing 11 in the rotary direction R in FIG. 3 . As a result, each blade 33 of the impeller 13 draws gas from the inner peripheral space to the outer peripheral side, sucks the gas from the air inlet 11b into the inner peripheral space of the impeller 13, and at the same time, the gas that is pushed out to the outer peripheral side of the impeller 13 passes through the air outlet 11a. send out. That is, the multi-blade air blower 10 sucks in air from the air inlet 11b, and sends out air from the air outlet 11a.

In such a multi-blade blower 10 , noise is generated due to turbulent eddies generated near the circular main plate 31 . Specifically, the noise is generated by the following mechanism.

Inside the impeller 13, the gas inhaled from the air inlet 11b mainly flows from the direction toward the circular main plate 31 to the outer periphery as shown in FIG. 1(a) (see gas flow W). But, as shown in Fig. 1 (b), a part of the air sucked from the air inlet 11b collides with the circular main board 31 near the circular main board 31 and then partially flows to the outer peripheral side (seeing the gas flow X). A turbulent vortex is generated in the gas flow X caused by the collision with the circular main plate 31 . The turbulent vortex follows the gas flow X to the outer peripheral direction, and then merges with the gas flow colliding with the circular main plate 31 . Moreover, the turbulent vortex of the gas flow X develops slowly, and the largest turbulent vortex is formed on the inner side of the blade 33, and the formed largest turbulent vortex is drawn out to the outer peripheral side by the blade 33, generating noise.

In addition, in such a multi-bladed air blower 10 , a vortex is generated centered on the vicinity of the outer peripheral end of the side plate 32 . The vortex does not contribute to the air blowing function of the impeller 13, resulting in a decrease in the efficiency of the blower and a cause of noise. Specifically, the vortex is generated by the following mechanism.

Inside the impeller 13, the gas inhaled from the air inlet 11b mainly flows from the direction toward the circular main plate 31 to the outer periphery as shown in FIG. 1(a) (see gas flow W). But, as shown in Fig. 1 (c), after a part of the gas in the casing 11 is drawn to the outer periphery of the impeller 13 near the side plate 32, it is sucked into the inner peripheral side of the impeller 13 from the vicinity of the bell mouth 12 of the impeller 13. The vortex Y. therefore. In the impeller 13, a considerable part of the ratio b/B (hereinafter referred to as blocking factor BF) of the axial length b of the vortex Y part to the axial full length B of the impeller 13 cannot effectively blow air, thus resulting in a decrease in blowing efficiency and noise.

For multi-blade blowers used in air conditioners, noise reduction is further demanded. In addition, the noise caused by the turbulent vortex near the circular main plate is not only generated by the multi-blade blower, but also a common problem of centrifugal blowers including turbo blowers.

Contents of the invention

The object of the present invention is to provide an impeller which can reduce noise, and to provide a low-noise centrifugal blower.

The impeller of the centrifugal blower described in the first aspect of the present invention includes: a main board rotating around the rotating shaft; a plurality of blades arranged in a ring shape centering on the rotating shaft, each one end of which is fixed on the main board; the other ends of the plurality of blades are connected side panels. In addition, a concavo-convex wave shape is formed in the vicinity of the inner peripheral side edges of at least a plurality of blades on the side plate side surface of the main plate.

In the impeller of such a centrifugal blower, since the concavo-convex shape is formed near at least the inner peripheral edge of the vane on the side plate side of the main plate, the impact of the gas flow on the main plate and the confluence of the gas flow develop. The turbulent vortex, which is destroyed and becomes smaller before reaching the blades. As a result, the noise generated when the blades extract the gas flow can be reduced.

As mentioned above, the turbulent vortex develops along with the flow from the inner peripheral side of the main plate to the outer peripheral side, and the most effective method is to make the turbulent vortex smaller just before being drawn out by the blades. That is, the corrugated shape forming position should be provided on the side plate side surface of the main plate at least in the vicinity of the inner peripheral side edge of the blade. More preferably, the corrugated shape is preferably set within the blade radial length range from the inner peripheral edge of the blade to the inner peripheral side, so as not to redevelop the turbulent vortex that has become smaller due to the destruction of the corrugated shape.

In addition, the corrugated shape may be provided not only in the vicinity of the inner side of the blade but also in the vicinity of the rotation axis. In this way, the turbulent vortices that are generated each time the gas flow hits the main plate can be minimized.

The impeller of the centrifugal blower described in the second aspect of the present invention includes: a main board that rotates around the rotating shaft; a plurality of blades that are arranged in a ring around the rotating shaft, and each one end is fixed to the main board; side panels. Moreover, the main plate side of the side plate is formed with a concavo-convex wave shape.

In the impeller of such a centrifugal blower, since the surface of the side plate on the side of the main plate is formed with a concave-convex wave shape, the pressure fluctuation near the outlet of the impeller on the side plate side is alleviated. In this way, the gas flow drawn to the outlet side by the impeller is difficult to be sucked into the inner peripheral side of the impeller from the side plate side of the impeller shaft direction again, so that the swirling vortex generated near the side plate becomes smaller, thereby making the As the BF value becomes smaller, the part of the impeller that can effectively supply air becomes larger, thereby improving the efficiency of the blower fan and reducing the noise.

In the impeller of the centrifugal fan according to the third aspect of the present invention, in the first or second aspect of the present invention, the wave shape is a triangular wave shape.

In the impeller of the centrifugal blower according to claim 4 of the present invention, in the first or second claim of the present invention, the waveform shape is a sinusoidal wave shape.

In the impeller of the centrifugal blower according to claim 5 of the present invention, in the first or second claim of the present invention, the waveform shape is a rectangular wave shape.

In the impeller of the centrifugal blower according to the sixth aspect of the present invention, in any one of the first to fifth aspects of the present invention, the wave pitch of the wave shape is in the range of not less than 2mm and not more than 8mm; the wave height is not less than 1mm , the range below 5mm.

In the impeller of the centrifugal blower according to any one of the third to sixth aspects of the present invention, the waveform shape and size are embodied.

When these wave shapes are provided near the inner peripheral side of the blade on the side plate side of the main board, the practicality of the wave shape is improved, and the wave shape is used to destroy and reduce noise that occurs on the side plate side of the main board The turbulent vortex near the inner peripheral side of the blade. Furthermore, when these corrugated shapes are provided on the main plate side of the side plate, the practicality of the corrugated shape for reducing the vortex near the side plate which causes the increase of the BF value is improved.

The centrifugal blower described in the seventh aspect of the present invention includes: the impeller as described in any one of the first to sixth aspects of the present invention; a driving device for rotating the main plate; The air inlet of the impeller and the air outlet that is arranged on the outer peripheral side of the impeller and sends out the gas in a direction approximately perpendicular to the rotating shaft, and covers the casing of the impeller.

In the above-mentioned centrifugal blower, if the main board is rotated by the driving device, the impeller rotates relative to the casing. At this time, each blade of the impeller draws the gas from the inner peripheral side space to the outer peripheral side space, and is pressed to the outer periphery of the impeller from the air inlet. The air on the side is sent out through the air outlet. That is, the centrifugal blower sucks air from the air inlet and sends air out from the air outlet.

At this time, due to the use of the impeller according to any one of the first to sixth aspects of the present invention, the waveform shape formed on the main plate is destroyed, and the impact of the gas flow on the main plate and the turbulent vortex generated by the gas flow merging are reduced. Therefore, the noise generated when the impeller pumps out the gas becomes smaller.

In addition, the wave shape formed on the side plate makes the vortex generated near the side plate smaller, thereby reducing the BF value and increasing the effective air supply part of the impeller, thereby improving the efficiency of the blower fan and reducing the noise. Small.

A brief description of the drawings

Fig. 1(a) is a side view of a conventional multi-blade blower (the casing part is a sectional view).

Fig. 1(b) is a side view of a multi-blade blower of a conventional example, and is an explanatory view of the mechanism of noise generation near the main board (partial sectional view of the impeller).

Fig. 1(c) is a side view of a multi-blade blower of a conventional example, and is a diagram for explaining the mechanism of noise generation near the side plate (partial sectional view of the impeller).

Fig. 2 is a perspective view of an impeller of a conventional multi-blade blower.

Fig. 3 is a plan view of an impeller of a conventional multi-blade blower.

Fig. 4 is a side view of the multi-blade blower according to the first embodiment (the housing portion is a sectional view).

Fig. 5 is a side view (partial sectional view) of an impeller of the multi-blade blower according to the first embodiment.

Fig. 6 is a plan view of the impeller of the multi-blade blower according to the first embodiment.

Fig. 7(a) is an enlarged view of the waveform shape (triangular waveform).

Fig. 7(b) is an enlarged view of the waveform shape (sinusoidal wave shape).

Fig. 7(c) is an enlarged view of the waveform shape (rectangular wave shape).

Fig. 8(a) is a side view of the multi-blade air blower according to the first embodiment, and is an explanatory diagram of the noise reduction effect of the wave shape formed on the main plate (showing a section of a partial impeller).

Fig. 8(b) is a side view of the multi-blade air blower according to the first embodiment, and is an explanatory view illustrating the noise reduction effect of the corrugated shape formed on the side plate.

Fig. 8(c) is a side view of the multi-blade air blower according to the first embodiment, and is an explanatory diagram of the noise reduction effect of the groove shape of the blade spacer on the main plate (showing a section of a partial impeller).

Fig. 9 is a cross-sectional plan view of an impeller of a turbo blower according to a second embodiment.

Detailed ways

first embodiment

(1) Composition of multi-blade blower

The multi-blade air blower (centrifugal air blower) according to one embodiment of the present invention differs only in the following point: in the impeller 13 of the multi-blade air blower 10 of the conventional example shown in FIGS. The side edge portion has a concavo-convex wave shape near the side plate 32, a concavo-convex wave shape is formed on the main plate 31 side of the side plate 32, and the front of the rotation direction of the plurality of blades 35 of the main plate 31 has a notch shape.

FIG. 4 is a side view of the multi-bladed air blower 40 according to this embodiment, and FIGS. 5 and 6 are side views and plan views of the impeller 43 of the multi-bladed air blower 40 .

The multi-blade air blower 40 is mainly composed of an impeller 63 , a housing 11 covering the impeller 63 , and a motor 14 for rotating the impeller 43 .

A plurality of blades 33 of the impeller 43 are fixed on the outer periphery of the disc-shaped main board 61 , and the other ends of the plurality of blades 33 are connected by an annular side plate 62 . Details of the impeller 43 will be described later.

A gas blowing port 11 a and an air inlet 11 b surrounded by a bell-shaped opening 12 are formed on the casing 11 . The air inlet 11b is disposed opposite to the side plate 62 of the impeller 43, and the gas flowing into the inner peripheral space of the impeller 43 through the air inlet 11b flows in in a form along the rotation axis O-O of the impeller 43, and flows away from the rotation axis O-O due to the rotation of the impeller 43. direction (impeller 43 peripheral direction). The air blowing port 11a is formed in a direction perpendicular to the air inlet port 11b so that the gas is blown out in a direction substantially perpendicular to the impeller rotation axis O-O.

The rotating shaft of the motor 14 is installed on the central hole 61a (see FIG. 6 ) of the main board 61 , and the impeller 43 is rotated as a whole by rotating the main board 61 . The main body of the motor 14 is fixed to the casing 11 .

Next, the impeller 43 will be described.

As shown in FIGS. 5 and 6 , the impeller 43 is composed of a main plate 61 , a plurality of blades 33 , and an annular side plate 62 . In this embodiment, the impeller 43 is a resin product in which the main plate 61 , the plurality of blades 33 and the side plates 62 are all integrally molded using a mold.

As shown in FIG. 6 , the main board 61 is a disc-shaped member forming a central hole 61 a, and the rotating shaft of the motor 14 is fixed in the central hole 61 a.

On the outer peripheral (side) edge of the main plate 61, a plurality of blades 33 described later are formed at equal intervals along the direction of rotation. In the vicinity of the inner peripheral side edges of the plurality of blades 33 , a concave-convex wave shape 64 is formed around the inner peripheral side edges. Here, the wave shape 64 has a triangular wave shape with a wave pitch P of 3 mm and a wave height H of 2 mm (see FIG. 7( a )). The waveform shape is not limited to a triangular wave shape, and may be a sinusoidal wave shape or a rectangular wave shape as shown in FIG. 7( b ) and FIG. 7( c ). The size of the waveform shape is not limited to the size of this embodiment, as long as the wave pitch P is in the range of 2 mm to 8 mm, and the wave height H is in the range of 1 mm to 5 mm.

Also, the inter-blade portion 65 located between the plurality of blades 33 of the main plate 61 is grooved forward in the rotation direction. The thickness of the inter-vane portions 65 in the circumferential direction is also greater than that of the vane 33 in the circumferential direction, and the length of the slots does not reach the rear of the other vane 33 adjacent to the front in the rotational direction. The interblade portion 65 is slotted radially along the shape of the blade 33 , and the length of the slot extends from the outer side edge to the inner side edge.

The blades 33 have a concave shape forward in the direction of rotation, and are members arranged in a plurality of rings around the rotation axis O-O. One end of the blade 33 is fixed on the outer periphery of the main board 61, and extends from there along the axis of rotation O-O without twisting. The other end of the blade 33 is connected with an annular side plate 62 as shown in FIGS. 5 and 6 .

The annular side plate 62 is disposed on the outer peripheral side of the other end of the blade 33 and connects the blades 33 . The side plate 62 can also be integrally formed with the main plate 61 and the plurality of blades 33 at the same time. Further, a concavo-convex wave shape 66 is formed on the side of the main plate 61 of the side plate 62 . Here, the wave shape 66 is the same as the wave shape 64 of the main board 61, and is a triangular wave shape with a wave pitch P of 3 mm and a wave height H of 2 mm (see FIG. 7( a )). In addition, the waveform shape is not limited to a triangular wave shape, and may be a sinusoidal wave shape or a rectangular wave shape as shown in FIG. 7( b ) and FIG. 7( c ). The dimensions of the waveform shape are not limited to those of the present embodiment, and the wave pitch P may be in the range of 2 mm to 8 mm; the wave height H may be in the range of 1 mm to 5 mm.

(2) Action of multi-blade blower

If the motor 14 rotates to make the multi-blade blower 40 work, the impeller 43 rotates relative to the casing 11 in the direction R shown in FIG. 6 . That is, in the multi-blade air blower 40, the gas is drawn out mainly by the surface turned forward that forms the concave surface of the blade 33, thereby, as the blade 33 of the impeller 43 draws gas from the space on the inner peripheral side of the impeller 43 to the space on the outer peripheral side, air is drawn from the air inlet. 11b sucks the gas into the inner peripheral space of the impeller 43, and the gas drawn out to the outer peripheral side of the impeller 43 is collected at the blower port 11a and blown out (see gas flow Z in FIG. 4). That is, the multi-blade blower 40 sucks in gas from the air inlet 11b along the rotation axis O-O, and sends out the gas in a direction perpendicular to the rotation axis O-O through the air supply port 11a. In addition, only the gas flow Z on the right side of the rotation axis O-O is shown in FIG. 4 , while on the left side of the rotation axis O-O, the gas drawn to the outer peripheral side of the impeller 13 flows along the casing 11 to the air outlet 11a and is blown out there.

(3) Transportation of the impeller

When the impeller 43 is transported, a plurality of impellers 43 are loaded in the direction of the rotating shaft O-O.

Here, the interblade portion 65 of the main plate 61 of the impeller 43 of the present embodiment is grooved as described above, and its circumferential thickness is greater than that of the blade 33, and its radial length is along the curved shape of the blade 33, and the thickness of the blade is determined by the blade 33. The outer peripheral side edge reaches the inner peripheral side edge. Using this shape, the two impellers 43 are overlapped from the rotation axis O-O direction, and the corresponding blades 33 of the other impeller 43 can be fitted into the slots of the plurality of inter-blade portions 65 of one impeller 43 . The two impellers 43 fitted in this way can be transported after being loaded to a prescribed loading height.

(4) Example

The result of the noise measurement experiment performed on the multi-blade air blower using the impeller of this embodiment is demonstrated.

In this experiment, a measurement experiment was performed on the air blower of the conventional example shown in FIG. 2 and FIG. 3 and the air blower of this embodiment shown in FIG. 5 and FIG. 6 . In addition, in this embodiment, for the purpose of noise reduction, the wave shape 64 formed on the main plate, the wave shape 66 formed on the side plate 62, and the slots of the interblade portion 65 of the main plate 61 are formed simultaneously. Therefore, in order to confirm the noise reduction effect of each of these three shapes, an impeller having only one shape of each of the above three shapes was prepared, and a noise measurement experiment was performed. The results of the noise measurement experiment are as follows:

① Only the main plate 61 of the impeller formed in the wave shape 64 reduces the noise value by 0.8dB compared with the conventional example.

② Only the side plate 62 is formed into the impeller of the wave shape 66, and the noise value is reduced by 0.5dB compared with the conventional example.

③ The noise value of the impeller in which only the inter-blade portion 65 on the main plate 61 has a grooved shape is reduced by 0.5 dB compared with the conventional example.

From the above results, it has been confirmed that the noise value can be reduced by applying any of the three shapes aimed at noise reduction in this embodiment.

(5) Features of multi-blade and multi-fan

The multi-blade air blower of this embodiment has the following features.

①Reduce noise by the wave shape formed on the impeller main board.

In the multi-blade air blower 10 of the conventional example, there is noise caused by the turbulent eddy in the vicinity of the main plate 31, and the specific mechanism of occurrence is as follows.

Inside the impeller 13, as shown in FIG. 1(b), a part of the gas is inhaled from the air inlet 11b, near the main board 31, collides with the main board 31 and then flows toward the outer peripheral side (see gas flow X). A turbulent vortex caused by collision against the main plate 31 occurs in the gas flow X. This turbulent vortex flows in the outer peripheral direction along with the gas flow X, and merges with the gas flow colliding with the main plate 31 again. Moreover, the turbulent vortex of the gas flow X gradually develops, and the largest turbulent vortex is formed at the inner peripheral side edge of the blade 33, which is drawn toward the outer peripheral side by the blade 33, generating noise.

On the other hand, in the impeller 43 of the multi-blade air blower 40 of the present embodiment, since the concave-convex wave shape 64 is formed near the inner peripheral side edge of at least the blade 33 on the side plate 62 side of the main plate 61, as shown in FIG. As shown in FIG. 8( a ), the turbulent vortex developed by the collision of the gas flow Z1 against the main plate 61 and the confluence of the gas flows is destroyed and becomes smaller before reaching the blade 33 . Therefore, noise generated when the blade 33 draws out the gas flow Z1 can be reduced.

②The noise is reduced by the wave shape formed on the side plate of the impeller.

In the multi-blade air blower 10 of the conventional example, a vortex is generated with the vicinity of the outer peripheral end of the side plate 32 as the center of the vortex. This vortex does not contribute to the air blowing operation of the impeller 13, and as a result causes a decrease in air blowing efficiency and noise. The specific mechanism of occurrence is as follows.

As shown in Figure 1(c), a part of the gas in the casing 11 generates a vortex Y near the side plate 32, and the vortex Y causes the above-mentioned gas to be drawn to the outer periphery of the impeller 13, and then flow from the bell mouth 12 of the impeller 13 again. Nearby is sucked into the inner peripheral side of the impeller 13 . Therefore, in the impeller 13, the ratio b/B (hereinafter referred to as the blocking factor BF) of the axial length b of the part where the vortex Y is generated to the axial full length B of the impeller 13 is equivalent, and effective air blowing operation cannot be performed. Therefore, the air blowing efficiency is low, and noise is generated.

In the impeller 43 of the multi-blade blower 40 of this embodiment, since the main plate 61 side of the side plate is formed with a concave-convex wave shape 66, the pressure fluctuation near the outlet of the impeller 43 of the side plate 62 is eased. Then, as shown in FIG. 8( b ), the gas flow extracted to the outlet side by the impeller 43 becomes difficult to be sucked to the inner peripheral side of the impeller 43 from the side plate side in the direction of the rotation axis of the impeller 43 again, and the vortex Z2 generated near the side plate 62 get smaller. Therefore, the BF value b1/B1 becomes smaller, and the portion of the impeller 43 that can effectively blow air becomes larger, so the efficiency of the blower can be improved, and the noise is also reduced.

③Reduce noise by slotting between blades of the main board of the impeller

In the impeller 43 of the multi-blade blower 40 of the present embodiment, the inter-blade portion 65 between the plurality of blades 33 of the main plate 61 is grooved at least forward in the direction of rotation, so as shown in FIG. Z3 collides against the main plate 61 and the turbulent vortex developed by the confluence of the gas flow, before being drawn out by the blades 33 , part of it escapes from the slotted interblade portion 65 to the axially outward side of the main plate 61 . Therefore, similar to the wave shape formed on the main plate 61 shown in FIG. 8( a ), it is possible to reduce the noise generated when the blade 33 draws out the gas flow.

Furthermore, in the interblade portion 65 of the impeller 43 according to the present embodiment, the portion in the circumferential direction forward of the main plate 61 in the rotational direction is grooved, and the groove does not reach the rearward direction of the rotational direction of the interblade portion 65 . Therefore, separation of the gas flow at the rear of the inter-blade portion 65 in the turning direction is not increased. The effect of reducing noise produced by slotting the interblade portion 65 forward in the rotation direction is not impaired.

In addition, the inter-vane portion 65 of the impeller 43 of the present embodiment is grooved from the outer peripheral side edge to the inner peripheral side edge of the blade 33, and the turbulent vortex of the gas flow Z3 can easily flow from the opening before reaching the outer peripheral side edge of the blade 33. The interblade portion 65 of the slot escapes. This can further reduce the turbulent vortex reaching the outer peripheral side edge of the blade 33 and reduce the noise.

④ Improved loading efficiency during impeller transportation

On the interblade part 65 of the main plate 61 of the impeller 43 of the present embodiment, as mentioned above, grooves are grooved, and its circumferential length is larger than the circumferential thickness of the blade 33, and the radial length is from the outer peripheral side edge of the blade 33 along the curved shape of the blade. to the inner peripheral edge. Utilizing this shape, the two impellers 43 can be overlapped from the direction of the rotating shaft O-O, and the corresponding blades 33 can be embedded in the slots of the plurality of interblade parts 65, thereby improving the loading efficiency of the impeller 43 during loading.

2nd embodiment

This embodiment is a case where the present invention is applied to an impeller of a turbo blower. That is, it is an embodiment in which the wave shape formed on the main plate 61 of the multi-blade blower 40 of the above-mentioned embodiment is applied to the impeller 73 of the turbo blower.

FIG. 9 is a plan sectional view of a turbo blower impeller 73 according to this embodiment.

The impeller 73 has a plurality of blades 93 fixed to the outer periphery of the disc-shaped main plate 91, and the other ends of the plurality of blades 93 are connected by a guard ring (side plate) not shown.

A plurality of blades 93 are formed at equal intervals in the direction of rotation on the outer periphery of the main plate 91 . A concavo-convex wave shape 94 is formed near the inner peripheral side edge of these plurality of blades 93 along the inner peripheral side edge. Here the waveform shape 94 is the same as the foregoing embodiment, and has a triangular wave shape shown in Fig. 7 (a) ~ Fig. 7 (c), a sine wave shape or a rectangular wave shape, the wave pitch P is in the range of more than 2mm and less than 8mm, and the wave height H is 1mm Above and below 5mm.

Even in this embodiment, as in the previous embodiment, the surface of the main plate 91 on the side of the guard ring is formed with a concave-convex wave shape 94 at least near the inner peripheral edge of the blade 93, so that the main plate 91 is blown by the gas flow. The turbulent vortex developed by the confluence of the collision and the gas flow is destroyed and becomes smaller before the flow reaches the vane 93, so that the noise generated when the vane 93 draws out the gas flow can be reduced.

other implementations

In the foregoing embodiments, the present invention is applied to the centrifugal blower using the impeller made of resin, but the present invention is also applicable to the centrifugal blower using the impeller made of sheet metal.

Possibility of industrial use

According to the present invention, the noise of the impeller of the centrifugal blower can be reduced.

Claims (7)

1. the impeller of a centrifugal blower (43,73), it possesses with rotating shaft (O-O) is the mainboard (61,91) of center rotation; With described rotating shaft (O-O) be the configuration of center ring-type, an end is fixed in the many pieces of blades (33,93) of described mainboard (61,91) separately; Connect the ring-type side plate (62) of described many pieces of blades (33, the 93) the other end, it is characterized in that, closely be close to place's shaping concave-convex shape waveform shape (64,94) in side plate (62) side interior all side portion of many pieces of blades (33,93) at least simultaneously of mainboard (61,91).

2. the impeller of a centrifugal blower (43), it possesses with rotating shaft (O-O) is the mainboard (61) of center rotation; With described rotating shaft (O-O) be the configuration of center ring-type, an end is fixed in the many pieces of blades (33) of described mainboard (61,91) separately; Connect the ring-type side plate (62) of described many pieces of blades (33) the other end, it is characterized in that, shaping concave-convex shape waveform shape (66) on the face of mainboard (61) side of described side plate (62).

3. the impeller of centrifugal blower as claimed in claim 1 or 2 (43,73) is characterized in that, described waveform shape (64,66,94) is a triangular waveform.

4. the impeller of centrifugal blower as claimed in claim 1 or 2 (43,73) is characterized in that, described waveform shape (64,66,94) is a sinusoidal waveform.

5. the impeller of centrifugal blower as claimed in claim 1 or 2 (43,73) is characterized in that, described waveform shape (64,66,94) is a square waveform.

6. as arbitrary impeller (43,73) that requires described centrifugal blower in the claim 1～5, it is characterized in that described waveform shape (64,66,94) is, the pitch of waves is more than the 2mm, the scope that 8mm is following, and wave height is more than the 1mm, the scope that 5mm is following.

7. a centrifugal blower is characterized in that, possesses arbitrary driving means (14) that requires described impeller (43,73) also to possess to make described mainboard (61,91) to rotate in the claim 1～6; Have with described side plate (62) in the intake grill (11b) of all side openings portion subtend, be located at described impeller (43,73) outer circumferential side, with gas towards with described rotating shaft (O-O) casing (11) air blowing opening (11a), that cover described impeller (43,73) sent of orthogonal direction slightly.

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