CN219509873U - Impeller, drainage pump and air conditioner outdoor unit - Google Patents

Abstract

The utility model discloses an impeller, a drainage pump and an air conditioner outdoor unit, wherein the impeller comprises: base, pivot, water conservancy diversion ring and blade group. The base is provided with a first surface, a second surface and a water passing hole, wherein the first surface and the second surface are oppositely arranged; the rotating shaft is arranged at the axis of the water passing hole; the guide ring is arranged around the outer edge of the first surface; the blade group comprises a plurality of main blades connected to the rotating shaft, and the plurality of main blades are radially connected to the first surface around the rotating shaft; the end part of the main blade, which is far away from the rotating shaft, protrudes out of the guide ring along the axis of the rotating shaft, and the outlet placing angle of the main blade is an obtuse angle. When the device is applied to the drainage pump, the generated noise is low while the drainage pump has a large lift.

Description

Impeller, drainage pump and air conditioner outdoor unit

Technical Field

The utility model relates to the technical field of drainage equipment, in particular to an impeller, a drainage pump and an air conditioner outdoor unit.

Background

When the outdoor air and the surface cooler of the air processing unit perform heat exchange to cool the dehumidified air during the refrigerating operation, the wall surface temperature of the surface cooler is lower than the dew point temperature of the outdoor air, water vapor contained in the outdoor air is precipitated on the wall surface of the surface cooler to form condensation, and when dew is increased to a certain degree, the condensation water slides down to a condensate tray below the surface cooler to form condensate water, and the condensate water generally drops into the condensate tray arranged below the heat exchanger. In order to drain condensed water accumulated in the condensate water tray, a drain pump is generally installed at the condensate water tray of the indoor unit of the air conditioner to drain accumulated water.

However, as the power of the air conditioner increases, the amount of condensate water generated is also large, so that the drain pump needs a large lift to meet the drain requirement, in the related art, the lift of the drain pump is generally increased by increasing the power, but, due to the increase of the power, a large noise is easily generated in the water pumping process.

Disclosure of Invention

The present utility model aims to solve at least one of the technical problems existing in the prior art. Therefore, the utility model provides the impeller which can have larger lift and smaller noise when applied to the drainage pump.

The utility model also provides a drainage pump with the impeller.

The utility model also provides an air conditioner outdoor unit with the drainage pump.

An impeller according to an embodiment of the first aspect of the present utility model comprises: base, pivot, water conservancy diversion ring and blade group.

The base is provided with a first surface, a second surface and a water passing hole, wherein the first surface and the second surface are oppositely arranged; the rotating shaft is arranged at the axis of the water passing hole; the guide ring is arranged around the outer edge of the first surface; the blade group comprises a plurality of main blades connected to the rotating shaft, and the main blades are radially connected to the first surface around the rotating shaft; the end part of the main blade, which is far away from the rotating shaft, protrudes from the guide ring along the axis of the rotating shaft, and the outlet placing angle of the main blade is an obtuse angle.

The impeller provided by the embodiment of the utility model has at least the following beneficial effects:

the end of the main blade is provided with a guide ring, and the end of the main blade, which is away from the water passing hole, protrudes from the surface of the guide ring, which is away from the base. For any main blade, a part of the main blade is positioned in the annular cavity of the guide ring, and a part of the main blade is positioned outside the annular cavity. When the liquid moves along the main blades towards the guide ring, the liquid flowing in the annular cavity can be blocked by the guide ring to be converged and turned, and after turning, the liquid can form an annular water curtain protruding out of the annular cavity, so that the liquid flowing outside the annular cavity is blocked by the annular water curtain to be converged with the annular water curtain, namely, the liquid on each main blade is mixed before flowing out of the impeller, and the liquid is uniformly contacted with the shell of the drainage pump, so that noise generated by contact of the liquid and the shell of the drainage pump is reduced. And the outlet setting angle of the main blade is an obtuse angle, so that the liquid flowing outside the annular cavity has a larger speed, and the speed of the converged liquid along the radial direction of the impeller is increased, so that the lift of the drainage pump is increased. Therefore, when the impeller is applied to the drainage pump, the drainage pump has lower noise and larger lift.

According to some embodiments of the utility model, the main blade comprises a first straight line portion and a first curve portion, one end of the first curve portion is connected to the rotating shaft, the other end of the first curve portion is connected to the first straight line portion, and an end portion, facing away from the first curve portion, of the first straight line portion faces the guide ring.

According to some embodiments of the utility model, the first straight portion is tangentially connected to the first curved portion.

According to some embodiments of the utility model, a gap is provided between some or all of the main blades and the guide ring.

According to some embodiments of the utility model, the blade set further comprises a plurality of auxiliary blades, the auxiliary blades are connected to the first surface and located between the hole edge of the water passing hole and the guide ring, and the plurality of auxiliary blades are radially distributed around the water passing hole.

According to some embodiments of the utility model, the outlet mounting angle of the auxiliary vane is an obtuse angle; and/or the number of the groups of groups,

the end part of the auxiliary blade, which is far away from the water passing hole, protrudes out of the surface of the guide ring, which is far away from the base; and/or the number of the groups of groups,

the auxiliary blade comprises a second linear part and a second curve part, one end of the second curve part is connected with the side edge of the water passing hole, the other end of the second curve part is connected with the second linear part, and the end part of the second curve part, which is away from the second curve part, faces the guide ring; and/or;

and part or all of the auxiliary blades are connected with the guide ring.

According to some embodiments of the utility model, the blade set further comprises a plurality of water absorbing blades, the water absorbing blades are connected to the water passing holes and protrude from the second surface, and the height of the water absorbing blades gradually decreases along the direction from the first surface to the second surface.

According to some embodiments of the utility model, the outlet setting angle of the main blade is 110 ° to 130 °.

A drain pump according to an embodiment of the second aspect of the utility model comprises the impeller described in the above embodiments.

The drainage pump provided by the embodiment of the utility model has at least the following beneficial effects:

by adopting the impeller of the embodiment of the first aspect, the tail end of the main blade is provided with the guide ring, and the end part of the main blade, which is away from the water passing hole, protrudes from the surface of the guide ring, which is away from the base. For any main blade, a part of the main blade is positioned in the annular cavity of the guide ring, and a part of the main blade is positioned outside the annular cavity. When the liquid moves along the main blade towards the guide ring, the liquid flowing in the annular cavity can be blocked by the guide ring to be converged and turned, and after turning, the liquid can form an annular water curtain protruding out of the annular cavity, so that the liquid flowing outside the annular cavity is blocked by the annular water curtain to be converged with the annular water curtain, the impact area of the liquid on the drainage pump shell is increased, and noise generated by contact between the liquid and the drainage pump shell is reduced. And the outlet setting angle of the main blade is an obtuse angle, so that the liquid flowing outside the annular cavity has a larger speed, and the speed of the converged liquid along the radial direction of the impeller is increased, so that the lift of the drainage pump is increased. Therefore, the drainage pump has lower noise and larger lift.

An outdoor unit of an air conditioner according to an embodiment of the third aspect of the present utility model includes the drain pump described in the above embodiment.

The air conditioner outdoor unit provided by the embodiment of the utility model has at least the following beneficial effects:

by adopting the drainage pump of the embodiment of the second aspect, the drainage pump has lower noise and larger lift, so that the working noise of the air conditioner outdoor unit is lower, and the drainage efficiency is faster.

Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.

Drawings

The utility model is further described with reference to the accompanying drawings and examples, in which:

FIG. 1 is a schematic view of an impeller according to an embodiment of the present utility model;

FIG. 2 is a schematic diagram of the flow of liquid;

FIG. 3 is a schematic view of FIG. 1 from another perspective;

FIG. 4 is an enlarged schematic view of area A of FIG. 3;

fig. 5 is a schematic view of fig. 1 from another perspective.

Reference numerals:

a base 100, a first surface 110, a second surface 120, and water passing holes 130;

a rotating shaft 200, a guide ring 300;

a blade group 400, a main blade 410, a first curved portion 411, a first straight portion 412, an auxiliary blade 420, a second curved portion 421, a second straight portion 422, and a water absorbing blade 430;

annular cavity 500, gap 600.

Detailed Description

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the utility model.

In the description of the present utility model, it should be understood that the direction or positional relationship indicated with respect to the description of the orientation, such as up, down, etc., is based on the direction or positional relationship shown in the drawings, is merely for convenience of describing the present utility model and simplifying the description, and does not indicate or imply that the apparatus or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

In the description of the present utility model, plural means two or more. The description of the first and second is for the purpose of distinguishing between technical features only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated. In addition, if "and/or", "and/or" and/or "are used throughout, the meaning includes three parallel schemes, for example," a and/or B ", including a scheme, or B scheme, or a scheme where a and B meet simultaneously. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present utility model.

In the description of the present utility model, unless explicitly defined otherwise, terms such as arrangement, installation, connection, etc. should be construed broadly and the specific meaning of the terms in the present utility model can be reasonably determined by a person skilled in the art in combination with the specific contents of the technical scheme.

The present embodiment provides an impeller, referring to fig. 1 to 3, fig. 1 is a schematic structural diagram of the impeller according to an embodiment of the present utility model, fig. 2 is a schematic flow direction of a liquid, and fig. 3 is a schematic view of another view of fig. 1, where the impeller according to the present embodiment includes a base 100, a rotating shaft 200, a guide ring 300, and a blade set 400.

The base 100 is configured as a disc, the base 100 has a first surface 110 and a second surface 120 that are opposite to each other, and a water passing hole 130 penetrating the first surface 110 and the second surface 120, the water passing hole 130 is located at the center of the base 100, and is used for pumping out liquid through the base 100 via the main vane. The opposite arrangement of the first surface 110 and the second surface 120 cannot be construed as that the first surface 110 is parallel to the second surface 120, and the first surface 110 and the second surface 120 may be planar or curved. The rotating shaft 200 is disposed at the axis of the water passing hole 130, and the rotating shaft 200 and the water passing hole 130 are coaxial. The guide ring 300 is disposed around the outer edge of the first surface 110, and defines an annular cavity 500 with the base 100. The blade set 400 includes a plurality of main blades 410, the plurality of main blades 410 are radially connected to the first surface 110 around the rotating shaft 200, and the ends of the main blades 410, which are close to each other, are connected to the rotating shaft 200, so that the rotating shaft 200 can drive the main blades 410 to rotate. For example, each main blade 410 is connected to a radial side of the rotation shaft 200 (as shown in fig. 1). Alternatively, the plurality of main blades 410 are connected to each other at the axial center of the water passing hole 130, and the axial end surface of the rotation shaft 200 is connected to each main blade 410, so long as the main blades 410 can be rotated by the rotation shaft 200. In addition, the impeller can be integrally formed, such as by a casting process, etc., depending on performance and cost requirements. Or formed by mutually splicing a plurality of parts, namely, the parts such as the main blade 410, the rotating shaft 200 and the like are firstly processed separately, and then are spliced by welding and other processes.

The end of the main vane 410 facing away from the rotation shaft 200 protrudes from the guide ring 300 facing away from the base 100 in the axial direction of the rotation shaft 200 (as shown in fig. 2, the arrow indicates the direction of the liquid flow). That is, for any of the main blades 410, one portion is located within the annular cavity 500 and another portion is located outside the annular cavity 500. Therefore, when the liquid moves along the main vane 410 toward the guide ring 300, the liquid flowing in the annular chamber 500 is blocked by the guide ring 300 and turned, and after the liquid is turned, an annular water curtain protruding out of the annular chamber 500 can be formed, so that the liquid flowing outside the annular chamber 500 is blocked by the annular water curtain and is converged therewith. That is, the liquid on each main vane 410 is mixed before flowing out of the impeller, increasing the impact area of the liquid on the casing of the drain pump, thereby relieving the impact force of the liquid on the casing, and reducing noise. Meanwhile, since the outlet seating angle α of the main vane 410 (an included angle between a tangent line of an end portion of the main vane 410 toward the outer edge of the base 100 and a tangent line of a point where the outer circle of the impeller intersects) is an obtuse angle (as shown in fig. 3), it is possible to make the liquid flowing outside the ring cavity 500 have a large velocity. Thus, during operation, fluid flowing outside the annulus 500 increases the velocity of the converging water flow in the radial direction of the impeller. When the impeller of the embodiment is used for the drainage pump, the drainage pump has a larger lift while having lower working noise.

Referring to fig. 3, the main vane 410 includes a first straight portion 412 and a first curved portion 411, one end of the first curved portion 411 is connected to the rotation shaft 200, the other end is connected to the first straight portion 412, and an end of the first straight portion 412 facing away from the first curved portion 411 faces the guide ring 300. It can be understood that, compared to a completely straight blade, the present embodiment can increase the length of the main blade 410 by using the combination of the first straight line portion 412 and the first curve portion 411, thereby increasing the lift of the drain pump, and in addition, the first straight line portion 412 is connected to the end of the first curve portion 412, so as to make the velocity change of the liquid smooth before the liquid flows out of the main blade 410, and reduce the kinetic energy loss of the liquid, thereby improving the drain efficiency of the drain pump.

On the basis of the above embodiment, the first straight line portion 412 is tangentially connected with the first curved line portion 411, that is, the first straight line portion 412 is smoothly connected with the first curved line portion 411, so that the liquid can flow between the first curved line portion 411 and the first straight line portion 412 more smoothly, so as to reduce the kinetic energy loss when the liquid flows from the first curved line portion 411 to the first straight line portion 412, thereby improving the drainage efficiency of the drain pump.

In the actual working process, because air exists in the working environment and the water body, large bubbles are easy to generate in the pump body in the pumping process of the drainage pump, and the large bubbles collide with the impeller and are extruded, so that the pressure cannot be released, and finally the large bubbles break to generate noise. Based on this, referring to fig. 3 and 4, fig. 4 is an enlarged schematic view of region a of fig. 3, in some embodiments, some or all of the main blades 410 have a gap 600 between them and the deflector ring 300. In operation, in the process of pushing the liquid by the main blade 410, the liquid can pass through the gap 600, so as to guide the large bubbles in the liquid to pass through the gap 600, avoid the large bubbles from being continuously pressed to cause cracking, and the large bubbles are limited by the structure of the gap 600 when passing through the gap 600, so as to be extruded and then decomposed, so that the large bubbles are changed into small bubbles. And when the gaps 600 are formed between all the main blades 410 and the guide ring 300, the bubbles pass through the gaps 600 for many times and are extruded for many times in a short time along with the continuous rotation of the impeller, the large bubbles are finally rapidly decomposed into a plurality of small bubbles, and the sound of single small bubbles is far smaller than that of single large bubbles, so that the effect of reducing noise is achieved.

Further, since the gap 600 is located at the end of the main vane 410, i.e., at the position where the linear velocity of the impeller is maximum, the gap 600 can pass through a longer path when the impeller rotates one turn, so that more large bubbles in the liquid are decomposed, thereby improving the bubble decomposing ability.

Referring to fig. 1, in some embodiments, the vane assembly 400 further includes a plurality of auxiliary vanes 420, the auxiliary vanes 420 being connected to the first surface 110, the auxiliary vanes 420 being located between the guide ring 300 and the hole edge of the water passing hole 130 and being radially distributed around the water passing hole 130. The auxiliary vane 420 can increase the number of vanes (collectively called the main vane 410 and the auxiliary vane 420) of the impeller, and when the impeller of this embodiment is applied to a drain pump, the lift of the drain pump can be increased. It should be noted that, in fig. 3, only one auxiliary vane 420 is provided between adjacent main vanes 410, and it should not be construed as the only limitation of the present embodiment, and any number of two, three, etc. auxiliary vanes 420 may be provided between adjacent main vanes 410 according to practical requirements, for example, when the impeller is large in size, so as to increase the drainage capacity of the impeller as much as possible in a limited space.

Referring to fig. 3, the outlet placement angle β of the auxiliary vane 420 is an obtuse angle to increase the speed of the liquid exiting the auxiliary vane 420, thereby increasing the head of the drain pump, based on the above embodiment.

In some embodiments, the end of the auxiliary blade 420 facing away from the water hole 130 protrudes from the surface of the guide ring 300 facing away from the base 100, and the principle thereof is the same as that of the main blade 410 protruding from the guide ring 300, which is not described herein.

Referring to fig. 3, in some embodiments, the auxiliary vane 420 includes a second straight portion 422 and a second curved portion 421, one end of the second curved portion 421 is connected to a side edge of the water passing hole 130, and the other end is connected to the second straight portion 422. The second straight portion 422 has an end facing away from the second curved portion 421 and faces the guide ring 300, and its principle is similar to that of the main vane 410 including the first straight portion 412 and the second straight portion 422, and will not be described herein.

In some embodiments, some or all of the auxiliary vanes 420 are connected to the baffle 300. It will be appreciated that the auxiliary vanes 420 have the greatest length when the auxiliary vanes 420 are connected to the guide ring 300, and thus the impeller has a greater lift when all the auxiliary vanes 420 are connected to the guide ring 300 (as shown in fig. 1). When a part of the auxiliary vane 420 is connected with the guide ring 300, that is, a gap 600 can be formed between the part of the auxiliary vane 420 and the guide ring 300, and when the liquid passes through the gap 600, large bubbles in the liquid can be further decomposed into small bubbles, so that the decomposing capability of the bubbles is improved, and the working noise of the drain pump is lower.

Referring to fig. 1 and 5, fig. 5 is another view of fig. 1, and in some embodiments, the blade set 400 further includes a plurality of water absorbing blades 430, wherein the water absorbing blades 430 are connected to the water passing holes 130 and protrude from the second surface 120 (as shown in fig. 5), and the height of the water absorbing blades 430 (the dimension of the water absorbing blades 430 perpendicular to the axis of the impeller) gradually decreases along the direction from the first surface 110 to the second surface 120. Specifically, the water absorbing vane 430 may be formed by a portion of the main vane 410 extending along the axis of the water passing hole 130 and passing through the water passing hole 130 (as shown in fig. 1). Or the water absorbing vane 430 is connected to the base 100, and the water absorbing vane 430 does not completely cover the water passing hole 130 so that the liquid can pass through the water passing hole 130. Alternatively, the rotation shaft 200 passes through the water hole 130, and the water absorbing blade 430 is connected to the rotation shaft 200, so long as the water absorbing blade 430 can rotate along with the rotation shaft 200, so as to achieve the purpose of absorbing water. In operation, as the water absorbing blades 430 rotate, liquid flows along the sides of the water absorbing blades 430 through the water holes 130 toward the main blades 410. In addition, in the present embodiment, since the height of the water absorbing blades 430 is gradually reduced, that is, the radial side surfaces of the plurality of water absorbing blades 430 along the water passing holes 130 are gathered, the side surfaces of the water absorbing blades 430 are inclined with respect to the axis of the water passing holes 130. When the impeller of the present embodiment is used for a drain pump, after the liquid is thrown out by centrifugal force, the liquid can be subjected to component force along the axial direction of the water passing hole 130, which is beneficial to the liquid flowing from the water absorbing blade 430 to the main blade 410, and improves the drainage capacity of the drain pump.

In some embodiments, the outlet setting angle α of the main vane 410 tends to range from 110 ° to 130 °. In particular, it was experimentally verified that when the outlet placement angle α of the main vane 410 is excessively large, an unstable state of the drain pump is easily generated during operation, and thus, in order to improve the stability during operation of the drain pump, the outlet placement angle α of the main vane 410 has a value ranging from 110 ° to 130 °. Similarly, in some embodiments, the outlet setting angle β of the secondary blade 420 ranges from 110 ° to 130 °.

The drain pump of the second aspect embodiment includes a housing, a driving motor, and the impeller of the above embodiments. The impeller and the driving motor are arranged in the shell, and the driving motor is connected with the rotating shaft 200 of the impeller and is used for driving the impeller to rotate.

Specifically, the end of the main vane 410 of the impeller is circumferentially provided with the guide ring 300, and the end of the main vane 410 facing away from the water hole 130 protrudes from the surface of the guide ring 300 facing away from the base 100. That is, for any of the main blades 410, a portion is located within the annular cavity 500 of the baffle ring 300 and a portion is located outside the annular cavity 500. Therefore, when the liquid moves along the main blades 410 toward the guide ring 300, the liquid flowing in the ring cavity 500 is blocked by the guide ring 300 to be collected and turned, and after turning, the liquid can form an annular water curtain protruding out of the ring cavity 500, so that the liquid flowing outside the ring cavity 500 is blocked by the annular water curtain to be collected with the annular water curtain, i.e., the liquid on each main blade 410 is mixed before flowing out of the impeller, so that the liquid is uniformly contacted with the shell of the drain pump, and noise generated by the contact of the liquid with the shell of the drain pump is reduced. Meanwhile, since the outlet seating angle α of the main vane 410 (an included angle between a tangent line of an end portion of the main vane 410 toward the outer edge of the base 100 and a tangent line of a point where the outer circle of the impeller intersects) is an obtuse angle (as shown in fig. 3), it is possible to make the liquid flowing outside the ring cavity 500 have a large velocity. Therefore, during operation, the liquid flowing outside the annular chamber 500 can increase the speed of the converged water flow along the radial direction of the impeller, so that the drainage pump has a larger lift while having lower working noise.

It should be noted that, since the present embodiment adopts all technical features of the impeller according to the first embodiment, the present embodiment has all the advantages brought by the embodiment of the first embodiment, and will not be described herein.

An embodiment of the third aspect of the air conditioner outdoor unit includes a heat exchanger, a water pan, and a drain pump of the embodiment of the second aspect. The water pan is arranged below the exchanger, and the drainage pump is arranged on the water pan. In the working process, the surface of the exchanger generates condensed water, the condensed water drops to the water receiving disc below along the surface of the heat exchanger, and the drainage pump is used for draining the condensed water in the water receiving disc out of the air conditioner outdoor unit. Because the drainage pump of the embodiment of the second aspect is adopted, condensed water can be quickly drained during the working process of the air conditioner outdoor unit, and the noise is low.

The embodiments of the present utility model have been described in detail with reference to the accompanying drawings, but the present utility model is not limited to the above embodiments, and various changes can be made within the knowledge of one of ordinary skill in the art without departing from the spirit of the present utility model.

Claims (10)

1. An impeller, comprising:

the base is provided with a first surface, a second surface and a water passing hole, wherein the first surface and the second surface are oppositely arranged;

the rotating shaft is arranged at the axis of the water passing hole;

the guide ring is arranged around the outer edge of the first surface;

the blade group comprises a plurality of main blades connected to the rotating shaft, and the plurality of main blades are radially connected to the first surface around the rotating shaft;

the end part of the main blade, which is far away from the rotating shaft, protrudes from the guide ring along the axial direction of the rotating shaft, and the outlet placing angle of the main blade is an obtuse angle.

2. The impeller of claim 1, wherein the main blade comprises a first straight portion and a first curved portion, one end of the first curved portion is connected to the rotating shaft, the other end is connected to the first straight portion, and an end of the first straight portion facing away from the first curved portion faces the guide ring.

3. The impeller of claim 2, wherein the first straight portion is tangentially connected to the first curved portion.

4. The impeller of claim 1, wherein some or all of the main blades have a gap with the guide ring.

5. The impeller of any one of claims 1 to 4, wherein the vane pack further comprises a plurality of auxiliary vanes connected to the first surface and located between the rim of the water passing hole and the deflector ring, and the plurality of auxiliary vanes are radially distributed around the water passing hole.

6. The impeller of claim 5, wherein the outlet placement angle of the auxiliary vane is an obtuse angle; and/or the number of the groups of groups,

the end part of the auxiliary blade, which is far away from the water passing hole, protrudes out of the surface of the guide ring, which is far away from the base; and/or the number of the groups of groups,

the auxiliary blade comprises a second linear part and a second curve part, one end of the second curve part is connected with the side edge of the water passing hole, the other end of the second curve part is connected with the second linear part, and the end part of the second curve part, which is away from the second curve part, faces the guide ring; and/or;

and part or all of the auxiliary blades are connected with the guide ring.

7. The impeller of claim 1, wherein the blade set further comprises a plurality of water absorbing blades connected to the water passing hole and protruding from the second surface, and the height of the water absorbing blades gradually decreases along the direction from the first surface to the second surface.

8. The impeller of claim 1, wherein the outlet setting angle of the main blades is 110 ° to 130 °.

9. Drain pump, characterized by comprising an impeller according to any of claims 1 to 8.

10. An outdoor unit of an air conditioner, comprising the drain pump of claim 9.