JP4687675B2 - Cross-flow blower and air conditioner - Google Patents

Description

The present invention relates to an air blower such as an air conditioner and an air purifier, and a once-through fan used in an air conditioner.

A conventional once-through fan has a configuration in which a plurality of impellers arranged in a circumferential direction and fixed by a ring are connected in the direction of the rotation axis. In recent years, air blowers and air conditioners are required to save power and be quiet, and one of the means is to improve the air blowing performance of the once-through fan. Increasing the rotation speed and diameter of the blower improves the amount of blown air, but causes problems such as input deterioration, increased noise, and unit dimensions. Therefore, in order to improve the performance of the blower itself, a technique for reducing the energy loss by controlling the flow near the blades is required. For example, an example is shown in which a step is provided on the axial center side of a blade to increase the static pressure and reduce noise (see Patent Document 1). Moreover, the shape which increased the thickness of the blade inner diameter side and prevented the separation at the time of airflow inflow is shown (see Patent Documents 2 and 3).

JP 2003-28089 A Japanese Patent Laid-Open No. 2001-193958 JP 2001-323891 A

The flow direction of the flow around the blade of the once-through fan is reversed during one rotation of the fan. After flowing into the blower, the flow that flows into the blower collides with the tip, and then flows along the surface opposite to the rotation direction of the blower and the blade suction surface. Produce. When peeling occurs, the efficiency of the blade decreases, and vortices are generated on the blade surface, causing noise deterioration.
On the other hand, if the direction of the blade tip is aligned with the flow direction, the separation can be reduced, but the flow loss at the outlet is increased because the width of the outlet channel is narrowed when flowing out from the blower. If emphasis is placed on the performance of either inflow or outflow, the performance of the other will deteriorate, so a shape suitable for both flows must be realized.
In addition, there is a problem in the blower characteristics when the resistance on the upstream side of the blower is changed. For example, when dust adheres to the filter mounted on the unit and the upstream resistance increases, the phenomenon of irregularly repeating blowing / suction (surging) and the reverse suction phenomenon from the blowing outlet may cause deterioration of the blowing performance or air conditioner Water droplets generated from the air that has flowed back to the air path adhere to the room and scatter into the room (dewdrop). This is because the blowout flow from the blades is extremely circumferential and gives a non-uniform wind speed distribution inside the unit wind path.

The present invention solves the above-mentioned conventional problems. In a once-through fan, even when a resistor adheres to the upstream side of the fan, the wind speed distribution inside the unit is made uniform, and the surging phenomenon and the reverse suction phenomenon are suppressed. An object of the present invention is to provide a blower that reduces the occurrence of separation during inflow.

The blower according to the present invention includes a large impeller in which a plurality of blades and a plurality of small impellers configured by rings that support both ends of the plurality of blades are connected in the rotation axis direction. Thus, in the cross-flow blower that sucks air from one side and blows air from the substantially opposite side through the inside of the large impeller, each of the plurality of small impellers has a plurality of thicker outer peripheral sides than the inner peripheral side. The first blade and a plurality of second blades whose inner peripheral side wall thickness is thicker than the outer peripheral side, and a larger number of first blades than the second blade, When two first blades are continuous in the circumferential direction, second blades are arranged at both ends of the blade pair, and when two second blades are consecutive in the circumferential direction, First on both ends By placing the blade constitutes a small impeller, the installation interval of the blade when the second blade are adjacent to each other, when the first and second blades are adjacent, or the first blade It is narrower than when they are adjacent to each other .

  The blower according to the present invention includes a large impeller in which a plurality of blades and a plurality of small impellers configured by rings that support both ends of the plurality of blades are connected in the rotation axis direction. Thus, in the cross-flow blower that sucks air from one side and blows air from the substantially opposite side through the inside of the large impeller, each of the plurality of small impellers has a plurality of thicker outer peripheral sides than the inner peripheral side. The first blade and a plurality of second blades whose inner peripheral side wall thickness is thicker than the outer peripheral side, and a larger number of first blades than the second blade, When two first blades are continuous in the circumferential direction, second blades are arranged at both ends of the blade pair, and when two second blades are consecutive in the circumferential direction, First on both ends In the cross-flow blower, even if a resistor is attached to the upstream side of the blower, the wind speed distribution inside the unit is made uniform so that the surging phenomenon or reverse suction phenomenon is achieved. It is possible to provide a blower that reduces the occurrence of separation during inflow while suppressing.

Embodiment 1 FIG.
FIG. 1 is an overall view of a cross-flow fan according to the present invention, and FIG. 2 is a cross-sectional view of an air conditioner incorporating the cross-flow fan according to the present invention. Moreover, FIG. 3 is the figure which expanded the suction side (A side of FIG. 2) of the braid | blade of the cross-flow fan of this invention.

As shown in FIG. 1, the cross-flow fan according to the present invention includes a large impeller 5 formed by connecting a predetermined number of small impellers 5 a that support both ends of a blade with two rings 4. As shown in FIG. 2, the once-through fan is incorporated in the air conditioner and rotates in the direction of the arrow 10 to suck air from one side (suction side A) and substantially opposite to the suction side A (outlet) Side) Air flow 11 is blown out from B. 6 is an air conditioner casing, 7 is an air conditioner filter, 8 is an electric dust collector incorporated in the air conditioner, and 9 is a heat exchanger. By incorporating the electric dust collector 8 and the heat exchanger 9 of the air conditioner, the resistance of the airflow on the upstream side of the blower is increased, and further, the resistance is increased by collecting dust or the like in the filter, and on the suction side of the blower Variations in the direction of the suction airflow.

Therefore, in the present invention, each of the small impellers 5a includes the first blade 18 that is thick on the outer peripheral side with respect to the inner peripheral side of the impeller and the second thicker on the inner peripheral side with respect to the outer peripheral side. These blades 19 are combined, and these are combined to form one small impeller 5a. The inner peripheral side or the outer peripheral side here is, for example, on the first blade 18, on an arc connecting the center point E of the inner peripheral tip of the blade 18 and the center point F of the outer peripheral tip of FIG. If the point X on the arc at the maximum thickness position is on the point E side with respect to the middle point G having the same arc length from the center point E of the inner periphery tip and the center point F of the outer periphery tip, the inner periphery If it is on the side, point F side, it indicates that it is on the outer peripheral side.

The ratio of the first blade 18 and the second blade 19 included in each small impeller is set so that the first blade 18 has a larger ratio, and the first and second blades 18 and 19 are small blades. Rather than being arranged at least alternately in the circumferential direction of the car, the combination of adjacent blades is arranged not to be continuous in the circumferential direction of the impeller.

Next, the operation will be described in comparison with a conventional example. FIG. 15 schematically shows a flow state in a conventional impeller. Further, FIG. 16 shows a case where the rotation direction of the blower is 10 and air flows into the blower (A side in FIG. 15). FIG. 17 is a view of the blade tip of a conventional impeller.
The airflow that has collided with the blade tip 2a flows along the suction surface 2c of the blade and leaves at a point C without being able to follow the suction surface (separation). When peeling occurs, the performance of the wing is degraded. As shown in FIG. 17, when the angle 24 formed by the direction of the straight line 23 passing through the inflow direction 20 and the center 21 of the outer wing tip R portion and the center of curvature 22 of the R portion is significantly different, The separation of thin wings is even greater.

The direction of the airflow flowing into the wing varies not only with the position of the wing but also with the shape and arrangement of the resistors such as filters and heat exchangers on the upstream side. In order not to increase the separation even if the air flow direction fluctuates, it is advantageous to use a blade having a thick tip at the outer peripheral side so that the tip does not peel off easily. However, when the air flows out of the blower, the flow path width 25 is narrowed on the outer peripheral side as shown in FIG. 18, so that the pressure loss is increased and the air cannot be sent out smoothly. A thin wing is ideal on the exit side.

Further, in the conventional blower, when the upstream resistance (for example, a filter, a dust collector or a heat exchanger) is changed, the blowout flow from the blades is extremely directed in the circumferential direction of the impeller, and the wind as shown in FIG. Uneven wind speed distribution 15 is formed inside the road, causing the phenomenon of irregularly repeating blowout / suction (surging) and the reverse suction phenomenon from the blowout port, resulting in the deterioration of the blowing performance and the air flowing back into the air conditioner's windway Water droplets generated from the water adhere to and splash into the room (exposure).

Therefore, in the first embodiment, the first blade 18 whose thickness increases in the radial direction of the impeller and the second blade 19 that decreases in the opposite direction are randomly arranged. As shown in FIG. 3, when air flows into the first blade 18, the flow 26 colliding with the blade tip is likely to follow along the suction surface 18 c, and the separation of the suction surface is suppressed. Further, since the surface area of the blade tip becomes large, when the first blade 18 and the second blade 19 are adjacent to each other, the flow collides on the pressure surface side 18d and the static pressure rises. A force 25 presses the flow 27 separated at the thin blade tip against the suction surface 19d.

When the first blades 18 are adjacent to each other, the interval between the blades on the outer peripheral side of the impeller is narrower than when the first blade 18 and the second blade 19 are adjacent to each other. Then, since the influence of the pressure increase generated in the adjacent first blade 18 is easily transmitted, the effect that the flow of separation is pressed against the suction surface is increased, so that the separation is more difficult to separate. In this case, the tendency of the air flow channel to spread is remarkable as it goes from the outer peripheral side to the inner peripheral side, but the flow pressed against the suction surface on the inlet side of the flow channel gradually increases in the outlet portion. Decrease and it becomes difficult to separate by suppressing the disturbance. As a result, noise is reduced. Furthermore, by converting the energy of the airflow from dynamic pressure to static pressure, the energy loss due to the viscous resistance of the air can be kept small.

On the other hand, when the second blades 19 are adjacent to each other, the blade interval on the airflow inlet side, that is, the outer peripheral side of the impeller is larger than when the first blade 18 and the second blade 19 are adjacent to each other. Become. For this reason, the effect of preventing peeling at the inlet side as described above cannot be expected.

To sum up the above, when looking at the suction side of the blower, the ratio of the first blade 18 to the second blade 19 is increased so that the first blade 18 and the second blade 19 have a larger ratio. By increasing the number of cases where the blades 19 are adjacent to each other and the case where the first blades 18 are adjacent to each other, it is possible to obtain a blower with less separation as a whole. This is particularly effective when the air conditioning unit incorporating a blower has a local pressure loss due to an electrostatic precipitator or a filter, and is designed with priority on prevention of separation. At this time, the first blade 18 and the second blade 19 are irregularly distributed so that neither the first blade 18 nor the second blade 19 is continuous more than a predetermined number, preferably three or more. To place. If the area where one or both of the blades are concentrated is made, the balance is easily lost when the blower rotates, and the shaft tends to wear, and the wind direction from the blower toward the air passage is biased so that it does not blow out over a wide range. This is because a surging phenomenon may occur when the upstream pressure loss increases.

Next, it will be described that the blower according to Embodiment 1 of the present invention has a uniform wind speed distribution on the air outlet side and can suppress phenomena such as surging and reverse suction. As for the portion where the blade shape is different, the blowing airflow direction is the pressure surface 19d of the second blade 19 with the thin tip at the rotational direction 10 and the negative pressure surface of the first blade 18 with the thick tip as shown in FIG. Between the blades adjacent to 18c, the airflow is directed in the direction of arrow 23b. On the contrary, between the blades adjacent to the negative pressure surface 19c of the second blade 19 and the pressure surface 18d of the first blade 18, the airflow is directed in the direction of arrow 23a. Turn to. In addition, when the first blade 18 is adjacent and the negative pressure surface 18c of one first blade 18 and the pressure surface 18d of the other first blade 18 are adjacent to each other, the airflow moves in the direction of the arrow 24a. If the second blade 19 is adjacent and the suction surface 19c of one second blade 19 and the pressure surface 19d of the other second blade 19 are adjacent to each other, the direction of the arrow 24b is Turn to.

When such a blower rotates, airflows directed in different directions as indicated by arrows 23a and 23b and arrows 24a and 24b are dispersed and repeated according to the arrangement of the blades. Can be sent to range. At that time, as described above, it is configured so that three or more identical blades are not continuously arranged. As a result, even when a resistor is added upstream, as in the case where the filter of the air conditioner is clogged with dust or the like, the air flow does not blow in only one direction, so the wind speed distribution in the air passage is not biased, Surging phenomenon and reverse suction phenomenon can be suppressed at the unit outlet, and the operating range of the air conditioner can be expanded.

Further, as shown in FIG. 6, only when the combination of adjacent blades is the combination of the second blades 19, the angular interval (pitch) of the arrangement of the blades is narrowed compared to the other combinations. By configuring in this way, since the space between the blades of the second blades 19 is narrower than those arranged at the same pitch, the flow velocity of the airflow is increased and separation can be suppressed. Further, compared to the case of the same blade arrangement interval, a distribution is given to the blade arrangement interval, and a peak sound having a frequency determined by the blade interval can be suppressed.

In addition, if another expression is given for the arrangement of the blades in which the same blade is not arranged in succession of three or more, when two first blades are consecutive in the circumferential direction, the second is attached to both ends of the blade pair. When the blades are arranged and two second blades are continuously arranged in the circumferential direction, the first blade is arranged at both ends of the blade pair to constitute a small impeller.

In the once-through fan of the first embodiment of the present invention, the number of the first blades is larger than that of the second blades. Therefore, when there are two or more blades, the first blades are always adjacent to each other when forming the impeller. A combination occurs. With regard to the arrangement of the blades, there are four patterns: first and second blades, first and first blades, second and first blades, and second and second blades. Of these four patterns, in order to prevent the same blades from being arranged continuously for three or more of them, this blade is used in the case of the first and first blades and the second and second blades. The blades adjacent to this pair must be of a different type than the blade pair. For example, the second blade is disposed at a location adjacent to the combination of the first and first blades, and the first blade is disposed at a location adjacent to the combination of the second and second blades.

Thus, by arranging so that three or more identical blades do not continue, with the rotation of the once-through blower, the direction of the airflow blown on the blowout side is dispersed, and even if a resistor is added upstream, There is no air flow in only one direction, and the wind speed distribution in the air passage is not biased. Therefore, the surging phenomenon and the reverse suction phenomenon can be suppressed at the unit outlet, and the operating range of the air conditioner can be expanded.

In addition, when the first blade 18 and the second blade 19 are simply arranged alternately, the pressure fluctuation generated at the blade tip when the blower rotates synchronizes with the rotation frequency and a peak sound is generated at a specific frequency. Although noise may be a problem, such a case is possible if the ratio of the first blades is increased and the combination of adjacent blades is not continuous in the circumferential direction as in the first embodiment. Can also be avoided.

As described above, the first embodiment of the present invention includes a large impeller in which a plurality of blades and a plurality of small impellers configured by rings that support both ends of the plurality of blades are connected in the rotation axis direction. In the cross-flow blower that sucks air from one side by the rotation of the large impeller and blows air from the substantially opposite side through the inside of the large impeller, each of the plurality of small impellers has a thickness on the outer peripheral side of the small impeller. Are arranged in the circumferential direction with a first blade thicker than the inner peripheral side and a second blade thicker on the inner peripheral side of the impeller than the outer peripheral side, and more first blades than the second blade Provided, when the two blades are continuous in the circumferential direction, the second blade is disposed at both ends of the blade pair, and when the two blades are continuous in the circumferential direction, Both blade pairs Since the cross-flow blower characterized in that the first blade is arranged in the small bladed wheel is used, the air flow can be blown out over a wide range, so that the surging phenomenon of the blower is suppressed and the air flow between the blades of the blower Without increasing the resistance, the flaking performance is improved by suppressing delamination that occurs in the blade. As a result, it is possible to reduce the noise of the blower or the air conditioner, reduce the unit input, and suppress the surging phenomenon.
In addition, when the first blade 18 and the second blade 19 are simply arranged alternately, the pressure fluctuation generated at the blade tip when the blower rotates synchronizes with the rotation frequency and a peak sound is generated at a specific frequency. However, such a case can be avoided if the ratio of the first blades is increased as in the first embodiment so that the combination of adjacent blades is not continuous in the circumferential direction.
As described above, the blower according to Embodiment 1 of the present invention is incorporated in a blower such as an air cleaner or an air conditioner, so that unit input is reduced and noise is reduced even with the same air volume as that of a conventional blower. Further, reverse suction and surging at the outlet can be suppressed.

Embodiment 2. FIG.
Here, the blade arrangement for adapting to the flow of the cross-flow fan of the first embodiment will be described. If the shape of the blade with a different thickness increasing direction in the radial direction is a similar shape (for example, if one blade shape is rotated / scaled, it overlaps with the other blade shape) Although a shape suitable for inflow / outflow must be realized, it is difficult to adapt to an asymmetric flow field at inflow / outflow.

Taking two types of blades with different thickness increasing directions as an example, the first blade 18 having a thick outer peripheral thickness is a deviation between the direction of the airflow flowing into the blower and the direction of the center line of the blade. The purpose is not to make the peeling of the suction surface 18c excessive even if the pressure is large, to apply a flow to the pressure surface 18d to increase the pressure of the pressure surface 18d and to press the flow of the suction surface of the adjacent blade against the blade surface, Ideally, the tip surface area should be increased.
On the other hand, the blade having a thin wall thickness on the outer peripheral side is intended not to narrow the flow path when flowing out of the blower, and is required to be as thin as possible.

Therefore, as shown in FIG. 7, the maximum thickness 31 a located on the outer peripheral side of the first blade 18 is made thicker than the maximum thickness 31 b located on the inner peripheral side of the second blade 19. As a result, the blades having a large outer wall thickness achieve a reduction in peeling of the suction surface during inflow. Further, since the area of the pressure surface tip is widened, the stagnation pressure due to the airflow collision is increased. As a result, the force of pressing the suction surface flow of the blade with a thin outer peripheral wall against the blade surface becomes strong, and it is possible to suppress the separation of adjacent blades.

On the other hand, by reducing the tip of the blade having a small outer peripheral wall thickness, it is possible to ensure a wide flow path width at the time of inflow of the blades on the blowing side. Therefore, the airflow is discharged smoothly.
From the above, the efficiency of the blower is improved compared to the case where the two types of blades have similar shapes, and a blower that reduces noise can be realized.

Embodiment 3 FIG.
In the second embodiment, the thickness of the blade with the thickness increasing direction changing in the radial direction is shown. In the third embodiment, a position where the thickness of the blade is maximized will be described.

When mounted on an air conditioner, an electric dust collector may be mounted, or a filter to which a resistor such as dust is added as it is used may cause local pressure loss. In that case, the flow direction flowing into the blade is different from the direction of the tip of the blade, or changes with time, so the blade tip and the suction surface should not be separated as much as possible when flowing into the blower. It is conceivable to increase the tip wall thickness. Therefore, as shown in FIG. 8, with respect to the first blade 18, the maximum thickness position 31 a is set to a position 35 in the vicinity of the outer peripheral end portion, the blade tip is thickened, and the second blade 19 is set to the maximum thickness position. The shape of 31b is shifted from the inner peripheral side to a position 36 near the center of the blade. This reduces the separation of the airflow flowing from the blade tip to the suction surface. At the same time, the pressure on the pressure surface side is increased and the air flow is pressed against the suction surface side of the second blade 19, and there is an effect of suppressing separation from the suction surface side.

On the other hand, if there is little bias in the wind speed distribution upstream of the blower as described above and the flow direction flowing into the blade is almost the same as the direction of the blade tip, the degree of flaking at the tip is small, so the blade tip thickness is reduced. The air blowing efficiency is improved by reducing the thickness and avoiding the collision of airflow. Therefore, as shown in FIG. 9, the first blade 18 has a shape in which the maximum thickness position 31a is shifted from the outer peripheral end to a position 33 in the vicinity of the center of the blade and the tip is thinned so as to follow the flow so as not to peel off the side surface shape. And
On the other hand, the second blade 19 has a shape in which the maximum thickness position 31b is set to a position 34 near the inner peripheral end in order to keep the flow path width constant and not increase the flow loss. If it does as mentioned above, while the flow 32 which flows in into an air blower suppresses peeling between a blade front-end | tip and a wing | blade, the flow resistance of the flow which flows out can be prevented, and ventilation efficiency improves.

Embodiment 4 FIG.
In Embodiment 3, only the thickness is targeted. Peeling is likely to occur on the negative pressure surface, and in order to enhance the delamination suppression effect, it is possible to expect further effects in preventing peeling by adjusting the negative pressure surface to give priority to warping. If the warpage of the pressure surface of the adjacent blade is reduced, the stagnation pressure increases due to the airflow collision, and the function of pressing the separated flow against the blade surface is further enhanced.

Therefore, as shown in FIG. 10, for the first blade 18, the warping of the negative pressure surface 18c is made larger than the warping of the pressure surface 18d. In this way, the suction surface swells to the side between the blades, and the flow separated at the tip of the blade becomes easier to follow along the blade surface, and it becomes possible to reduce separation and loss.

On the other hand, the warp of the negative pressure surface 19c is larger than the warp of the pressure surface 19d with respect to the second blade 19 as well. In this way, the pressure surface 18d swells to the side between the blades, and an air flow collides with the pressure surface, so that the pressure rise easily occurs. Then, a force that presses the suction surface flow 32 of the adjacent blade 19 against the suction surface 19c of the adjacent blade acts, and it becomes possible to suppress separation.

Furthermore, on the air flow blowing side, as shown in FIG. 11, the angle formed by the air flow directions 23c and 23d between the adjacent blades is increased, and the air can be blown in a wider range. Therefore, even if a strong resistor is added on the upstream side of the blower because dust accumulates on the filter, a surging phenomenon is unlikely to occur.
As described above, it is possible to realize a blower capable of suppressing the surging by suppressing the separation of the blade surface and improving the blowing performance.

In other words, the first blade 18 has a longest distance 42a from the reference line to the suction surface with the arc 41 connecting the centers of both blade tips R as shown in FIG. It is longer than the longest distance 43a to the surface. If it does so, in the negative pressure surface, since the surface along a flow is formed, peeling can be suppressed small.
On the other hand, in the second blade 19, the longest distance 42b from the reference line to the pressure surface is longer than the longest distance 43b from the reference line to the suction surface. If it does so, it will become the shape where the pressure surface swelled, and the airflow which flowed in will collide and it will be easy to raise surface pressure. As a result, the air flow 32 flowing on the negative pressure surface 19c of the second blade 19 is pressed against the negative pressure surface 19c, thereby reducing the separation.
Further, due to the difference in thickness between the pressure surface and the suction surface, the outlet flow directions 23 and 24 are likely to be different, and the wind direction 25 to be blown out is wide. As a result, it is possible to realize a blower that equalizes the wind speed distribution in the air path and prevents surging or reverse suction.
If it carries out as mentioned above, a blower with high ventilation performance which controlled separation at the blower suction side and secured a channel width on the blowout side can be realized.

Embodiment 5 FIG.
Until now, it was intended for one cross section of each small impeller 5a. Here, the form of the large impeller 5 in which the small impeller 5a is connected in the axial direction of the cross-flow fan will be described with reference to FIGS.

  The air flow speed and the direction of flowing into the blower differ depending on the air path inside the unit. Considering an example of an air conditioner, the air blower central portion 44 shown in FIG. 13 has few obstacles that become airflow resistance, so the inflow air velocity is the highest, and the air blower end portion 45 is affected by the influence of the side wall and the casing. Wind speed is low. Since the blade peripheral speed 46 of the blower is constant in the axial direction, for example, as shown in FIG. 14A, even if the relative velocity 32a of the air flow with respect to the blower in the blower central portion 44 is along the blade surface, as shown in FIG. Thus, since the inflow absolute velocity 47 is smaller than the central portion at the blower end portion, the relative velocity vector 32b does not follow the blade surface and the separation of the suction surface increases. Therefore, the performance of the entire blower is not improved.

Therefore, the shape of the impeller is changed between the central portion and the end portion of the blower. For example, since the direction of the airflow flowing in at the central portion 44 and the direction of the blade tip are substantially the same, the blade shape / arrangement as shown in FIG. Because of fear of peeling, the blade shape / arrangement as shown in FIG. 7 of the second embodiment is applied. Thereby, it is possible to realize a blower with reduced separation in accordance with the airflow distribution at the center and end of the blower. Since the pair of blades used for preventing peeling at the end of the blower has a function of blowing out the blowing direction over a wider range than the central portion, the effect of suppressing the surging phenomenon that easily occurs at the end of the unit is strong.
As described above, it is possible to realize a blower / air conditioner having improved fan performance, reduced unit input, and surging strength.

It is a figure of the once-through blower concerning Embodiment 1 of the present invention. It is sectional drawing of the air conditioner using a once-through blower. It is the figure which expanded the suction side of the braid | blade of the once-through fan of Embodiment 1 of this invention. It is the figure which expanded the blowing side of the braid | blade of the once-through fan of Embodiment 1 of this invention. It is the figure which showed the mode of the blowing flow of the cross-flow fan of Embodiment 1 of this invention. It is the figure which showed the example which changes the pitch of a braid | blade in the crossflow fan of Embodiment 1 of this invention. It is an enlarged view of the 1st and 2nd braid | blade of Embodiment 2 of this invention. It is an enlarged view of the 1st and 2nd braid | blade of Embodiment 3 of this invention. It is an enlarged view of another example of the 1st and 2nd braid | blade of Embodiment 3 of this invention. It is an enlarged view of the suction side of the once-through fan of Embodiment 4 of this invention. It is an enlarged view of the blowing side of the cross-flow fan of Embodiment 4 of this invention. It is an enlarged view of the suction side of the once-through fan of Embodiment 4 of this invention. It is a general view of the once-through fan in Embodiment 5 of this invention. It is the enlarged view (a) of the suction side of the center part of the cross-flow fan in Embodiment 5 of this invention, and the enlarged view (b) of the suction side of an edge part. It is a schematic diagram of the airflow in the conventional impeller. It is a schematic diagram of the air inflow side of the conventional air blower. It is a figure of the blade front-end | tip part of the conventional impeller. It is a schematic diagram by the side of the air outflow of the conventional air blower.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cross-flow fan 2 Blade 3 Circumferential direction 4 Ring 5 Large impeller 5a Small impeller 6 Air conditioner 7 Dust filter 8 Electric dust collector 9 Heat exchanger 10 Blower rotation direction 11
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18 first blade 19 second blade 18c first blade suction surface, 18d first blade pressure surface 19c second blade suction surface, 19d second blade pressure surface

Claims (5)

It is equipped with a large impeller in which a plurality of blades and a plurality of small impellers composed of rings that support both ends of the plurality of blades are connected in the rotation axis direction, and the rotation of the large impeller sucks air from one side. In the once-through fan that blows air from the substantially opposite side through the inside of the large impeller,
The plurality of small impellers include a plurality of first blades whose outer impeller outer wall thickness is thicker than the inner peripheral side, and a plurality of second blades whose impeller inner peripheral wall thickness is thicker than the outer peripheral side, together formed by arranging in the circumferential direction,
Providing more first blades than the second blade;
When the two first blades are continuous in the circumferential direction, the second blade is disposed at both ends of the blade pair,
If the second blade each other successive two in the circumferential direction to constitute a small impeller by placing a first blade to both ends of the blade pairs,
The installation interval of the blades when the second blades are adjacent to each other is narrower than the case where the first and second blades are adjacent or the first blades are adjacent to each other. Cross-flow blower. The maximum thickness of the first blade, once-through blower of claim 1, wherein a thickness greater than the maximum thickness of the second blade. The maximum thickness position of the first blade is arranged in the vicinity of the outer peripheral side end portion of the blade, and the maximum thickness position of the second blade is arranged in the vicinity of the center portion of the blade. The once-through blower according to claim 1 or 2 . The surface of the blade facing the rotation direction of the impeller is a pressure surface, the surface opposite to the pressure surface is a suction surface, and the warping of the suction surfaces of the first and second blades is the pressure surface. The cross-flow blower according to any one of claims 1 to 3 , wherein the cross-flow blower is larger than the warp. An air conditioner equipped with the once-through fan according to any one of claims 1 to 4 ,
The maximum thickness position of the first blade of the small impeller disposed at the longitudinal end of the large impeller is the maximum thickness of the first blade of the small impeller at the longitudinal center of the large impeller. It is located on the outer peripheral side of the blade from the position,
The maximum thickness position of the second blade of the small impeller disposed at the longitudinal end of the large impeller is the maximum thickness of the second blade of the small impeller at the longitudinal center of the large impeller. An air conditioner that is located on the outer peripheral side of the blade from the position.

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