The present invention relates to a drain pump, and an air conditioner provided therewith.
It is known to provide a drain pump in an air conditioner in order to discharge drain water generated in a heat exchanger during cooling operation, draining operation, and the like. Such a drain pump is built into a ceiling embedded type air conditioner 1 as shown in, for example,
The air conditioner 1 comprises a casing 2 that internally houses various constituent equipment, and a face panel 3 disposed on the lower side of the casing 2. Specifically, the casing 2 of the air conditioner 1 is disposed so that it is inserted in an opening formed in a ceiling U of an air conditioned room. Furthermore, the face panel 3 is disposed so that it is fitted into the opening of the ceiling U. Principally disposed inside the casing 2 are: a fan 4 that sucks air inside the air conditioned room through an inlet 31 of the face panel 3 into the casing 2, and blows the same out in the outer circumferential direction; and a heat exchanger 6 disposed so that it surrounds the outer circumference of the fan 4. In the face panel 3 are formed: an inlet 31 that sucks in the air inside the air conditioned room; and outlets 32 that blow out the air from inside the casing 2 into the air conditioned room.
A drain pan 7 for receiving the drain water generated in the heat exchanger 6 is disposed on the lower side of the heat exchanger 6. The drain pan 7 is mounted to the lower part of the casing 2. The drain pan 7 comprises: an inlet 71 formed so that it communicates with the inlet 31 of the face panel 3; outlets 72 formed so that they correspond to the outlets 32 of the face panel 3; and a drain receiving groove 73 formed on the lower side of the heat exchanger 6 and that receives the drain water. In addition, a bell mouth 5 for guiding the air sucked in from the inlet 31 to the impeller 41 of the fan 4 is disposed in the inlet 71 of the drain pan 7. Further, a drain pump 308 that discharges the drain water collected in the drain receiving groove 73 out of the casing 2 is disposed in the portion of the drain receiving groove 73 of the drain pan 7 where the heat exchanger 6 is not disposed (specifically, between the outlets 72). The drain pump 308 is connected via a discharge pipe (not shown) disposed outside of the casing 2.
As shown in
The pump casing 81 principally comprises: a casing main body 84 comprising an opening at the upper part and disposed so that it surrounds the sides of the impeller 382; a casing cover 85 disposed so that it covers the opening of the upper part of the casing main body 84; and a sealing member 86 for sealing the space between the casing main body 84 and the casing cover 85. The casing main body 84 comprises: a cylindrically shaped main body part 84a whose diameter decreases in the downward direction; a tubular shaped suction part 84b comprising a drain inlet 81a at the lower end part and extending downward from the lower end part of the main body part 84a; and a tubular shaped discharge nozzle part 84c extending sideways from the drain outlet 81b formed at the side part of the main body part 84a. As shown in
As shown in
The shaft part 91 passes through the inside of the air introduction part 85a, and is disposed so that a gap is formed between the outer circumferential surface of the shaft part 91 and the inner circumferential surface of the air introduction part 85a of the casing cover 85.
The main blade 392 comprises, for example: four first blades 395 extending radially from the outer circumferential surface of the shaft part 91; and four second blades 396 extending radially from the outer circumferential edge part of the opening 93a of the dish part 93, and disposed between the first blades 395 in the circumferential direction. The height position of the upper end part of each first blade 395 (hereinafter, the height of each first blade 395 and each second blade 396 from the upper end surface of the opening 93a to the upper end part is defined as a blade height H1, as shown in
The dish part 93 is disposed along a reduced diameter portion of the main body part 84a, and the annular partition part 93b extending upward from the outer circumferential edge part thereof is disposed so that it couples with the outer circumferential edge part of the main blade 392. The upper end part of the partition part 93b is disposed at a position lower than the upper end part of the main blade 392 (hereinafter, the height from the upper end surface of the opening 93a to the upper end part of the partition part 93b of the dish part 93 is defined as a dish height H2, as shown in
The impeller 382 of the drain pump 308 so constituted rotates in a prescribed direction when the motor 83 is driven. In so doing, a part of the suction part 84b is submerged to a point lower than the water surface of the drain water collected in the drain receiving groove 73 of the drain pan 7, and the drain water collected in the drain receiving groove 73 is consequently sucked in from the drain inlet 81a by the auxiliary blade 94, rises inside the suction part 84b, and reaches the main body part 84a. Further, the drain water that reaches the main body part 84a is boosted by the main blade 392, and then discharged from the drain outlet 81b via the discharge nozzle part 84c to the outside of the casing 2 of the air conditioner 1. Specifically, the drain water discharged from the drain outlet 81b is discharged via the discharge pipe disposed outside of the casing 2 and connected to the discharge nozzle part 84c. Here, the water surface that rose to the main body part 84a is substantially vertically divided into parts by the dish part 93, the flow of the drain water is partially blocked so that the flow is limited, and the drain water that contacts the main blade 392 is discharged (e.g., refer to Japanese Published Patent Application No. H10-115294, 2000-80996, 2000-240581, and 2001-342984).
Moreover, the discharge flow rate can be regulated by the water level h (refer to
Here, as the water level h inside the main body part 84a of the drain pump 308 falls, an air layer expands (refer to an air-liquid interface X in
In addition, the back pressure may decrease depending on, for example, the installation conditions (piping length, inner diameter, height, etc.) of the discharge pipe connected to the drain outlet 81b. In such a case, the head of the drain pump 308 decreases, which consequently expands the air layer circularly concentric with the shaft part 91 of the main blade 392.
Compared with a pump of a type wherein an impeller is generally submerged completely, such a drain pump 308 is constituted so that the air-liquid interface between the air and the water is formed at a portion where the main blade 392 is disposed; consequently, the pump efficiency is low and the operating noise is loud. Further, this operating noise is generated principally by the agitation of the air layer by the main blade 392, and the air layer acceleratedly increases the more it expands on the outer circumferential side of the main blade 392. Particularly when the head is low, the air-liquid interface between the air and the water (refer to an air-liquid interface Y in
In contrast, with the aim of reducing the operating noise by making the air-liquid interface Y above the upper end part of the partition part 93b flow smoothly, it is also known to employ the impeller 382 provided with inclined parts 395a, 396a at the outer circumferential part of the main blade 392 (specifically, the first and second blades 395, 396) only at the portion on the upper side of the upper end part of the partition part 93b (i.e., the portion between the blade height H1 and the dish height H2), as shown in
It is an object of the present invention to reduce the operating noise of a drain pump when the head is low.
A drain pump according to the first invention comprises a casing and an impeller. The casing comprises: a drain inlet for sucking in drain water at a lower end part; and a drain outlet for discharging drain water at a side part. The impeller comprises: a shaft part disposed inside the casing so that it extends in the vertical direction; a main blade disposed on the outer circumferential side of the shaft part; an auxiliary blade disposed on the lower side of the main blade; and a disc shaped dish part disposed between the main blade and the auxiliary blade and comprising an opening in the center. The dish part further comprises an annular partition part extending upward from the outer circumferential edge part thereof. The outer circumferential edge part of the main blade is disposed at a position lower than the upper end part of the partition part.
With this drain pump, the outer circumferential edge part of the main blade, where the circumferential velocity is high, is disposed at a position lower than the upper end part of the partition part; consequently, even if the air-liquid interface between the air and the water expands to the outer circumferential part, where the circumferential velocity is high, when the head is low, the collision between the air-liquid interface and the outer circumferential part of the main blade can be softened, and the operating noise can be reduced. The operating noise can be reduced effectively particularly if an operating condition of low head overlaps an operating condition of low water level.
Moreover, because the portion disposed at a position lower than the upper end part of the partition part is the outer circumferential edge part of the main blade, which has a high circumferential velocity and significantly affects operating noise, it reduces the effect of softening the collision between the air-liquid interface and the main blade for the inner circumferential part of the main blade, which has a comparatively small effect on operating noise, while softening the collision between the air-liquid interface and the main blade in the vicinity of the outer circumferential edge part of the main blade, and ensures an effective area by which the main blade can perform the work of supplying water, which enables a drop in performance of the drain pump to be suppressed as much as possible.
Thereby, with this drain pump, the operating noise can be reduced when the head is low while suppressing a drop in the pump performance.
A drain pump according to the second invention is the drain pump according to the first invention, wherein the outer circumferential edge part of the main blade is disposed on the inner circumferential side of the inner circumferential surface of the partition part.
With this drain pump, the outer circumferential edge part of the main blade is disposed on the inner circumferential side of the inner circumferential surface of the partition part of the dish part, and the diameter of the main blade is less than the diameter of inner circumferential surface of the dish part; consequently, it is possible to enhance the effect of softening the collision between the air-liquid interface and the main blade at the outer circumferential edge part of the main blade.
A drain pump according to the third invention is the drain pump according to the first invention or the second invention, wherein the outer circumferential part of the main blade is inclined so that a blade height decreases toward the outer circumferential edge part.
With this drain pump, the main blade is formed so that the blade height of the outer circumferential part of the main blade decreases toward the outer circumferential edge part, and it is easier to further ensure an effective area at the outer circumferential part of the main blade by which the main blade can perform the work of supplying water; consequently, it is possible to further suppress a drop in the performance of the drain pump.
A drain pump according to the fourth invention comprises a casing and an impeller. The casing comprises: a drain inlet for sucking in drain water at a lower end part; and a drain outlet for discharging drain water at a side part. The impeller comprises: a shaft part disposed inside the casing so that it extends in the vertical direction; a main blade disposed on the outer circumferential side of the shaft part; an auxiliary blade disposed on the lower side of the main blade; and a disc shaped dish part disposed between the main blade and the auxiliary blade and comprising an opening in the center. The main blade is formed so that the blade height decreases from the inner circumferential edge part toward the outer circumferential edge part thereof.
With this drain pump, the blade height of the main blade decreases from the inner circumferential edge part toward the outer circumferential edge part; consequently, it is possible to soften the collision between the air-liquid interface and the main blade in any of these cases: the case where, when the head is low, the air-liquid interface between the air and the water expands to the outer circumferential part, where the circumferential velocity is high; and the case where, when the head is low, the air-liquid interface is positioned at the inner circumferential part, more so in the case when the water level is rising than when the water level is low.
Thereby, with this drain pump, the operating noise can be reduced when the head is low, even if the position of the air-liquid interface varies due to variations in the water level.
A drain pump according to the fifth invention comprises a casing and an impeller. The casing comprises: a drain inlet for sucking in drain water at a lower end part; and a drain outlet for discharging drain water at a side part. The impeller comprises: a shaft part disposed inside the casing so that it extends in the vertical direction; a main blade disposed on the outer circumferential side of the shaft part; an auxiliary blade disposed on the lower side of the main blade; and a disc shaped dish part disposed between the main blade and the auxiliary blade and comprising an opening in the center. The jagged part, wherein the blade height varies with the jagged shape, is formed at least the outer circumferential part of the main blade.
With this drain pump, a jagged part is formed at the outer circumferential part of the main blade, where the circumferential velocity is high; consequently, even if, when the head is low, the air-liquid interface between the air and the water expands to the outer circumferential part where the circumferential velocity is high, the collision between the air-liquid interface and the outer circumferential part of the main blade can be softened, and the operating noise can be reduced. The operating noise can be reduced effectively particularly if the operating condition of low head overlaps the operating condition of low water level.
Moreover, if the jagged part is formed also at the inner circumferential part of the main blade, the collision between the air-liquid interface and the main blade can be softened in any one of these cases: the case where, when the head is low, the air-liquid interface between the air and the water expands to the outer circumferential part, where the circumferential velocity is high; and the case where, when the head is low, the air-liquid interface is positioned at the inner circumferential part, more so in the case when the water level is rising than when the water level is low.
Thereby, with this drain pump, the operating noise can be reduced when the head is low, even if the position of the air-liquid interface varies due to variations in the water level.
An air conditioner according to the sixth invention comprises: a heat exchanger; a drain pan for collecting drain water generated by the heat exchanger; and a drain pump as recited in any one invention of the first invention through the fifth invention that discharges the drain water collected in the drain pan.
With this air conditioner, the noise of the entire air conditioner can be reduced because the drain pump whose operating noise is low when the head is low is used to discharge the drain water collected in the drain pan.
The following explains the embodiments of a drain pump and an air conditioner provided therewith according to the present invention, referencing the drawings.
The impeller 82 principally comprises: a shaft part 91 coupled to a drive shaft of the motor 83; a main blade 92 disposed inside a main body part 84a of the pump casing 81; an auxiliary blade 94 disposed on the lower side of the main blade 92; and a disc shaped dish part 93 disposed between the main blade 92 and the auxiliary blade 94, and having an opening 93a comprising an annular through hole in the center. Here, excepting the main blade 92, the explanation of the impeller 82 is abbreviated because its constitution is the same as a conventional impeller 382.
The main blade 92 comprises, for example: four first blades 95 extending radially from the outer circumferential surface of the shaft part 91; and four second blades 96 extending radially from the outer circumferential edge part of the opening 93a of the dish part 93, and disposed between the first blades 95 in the circumferential direction. Furthermore, the number of first blades 95 and second blades 96 that constitute the main blade 92 is not limited to the abovementioned number, and various numbers thereof can be chosen.
The height position of the upper end part of each first blade 95 (hereinafter, the height of each first blade 95 and each second blade 96 from the upper end surface of the opening 93a is defined as a blade height H1, as shown in
Furthermore, the inclined parts 95a, 96a are formed so that one part of the outer circumferential part of each first blade 95 and each second blade 96 is notched, and are shaped inclined so that the blade height H1 shortens toward the outer circumferential edge part. In addition, the outer circumferential edge part of each of the inclined parts 95a, 96a is disposed at a position lower than the upper end part of the partition part 93b.
In addition, the inclined parts 95a, 96a are notched so that the outer diameter of each first blade 95 and each second blade 96 is shorter than an external dimension D of the partition part 93b, and further is shorter than a diameter d of the inner circumferential surface of the partition part 93b. Consequently, the outer circumferential edge part of each first blade 95 and each second blade 96 is disposed on the inner circumferential side of the inner circumferential surface of the partition part 93b. Furthermore, each of the inclined parts 95a, 96a may be shaped linearly inclined, as shown in
With a drain pump 8 having a main blade 92 wherein such inclined parts 95a, 96a are formed, the air layer expands circularly concentric with the shaft part 91 of the main blade 92 as the water level h falls, the same as the inside of the main body part 84a of a conventional drain pump 308. Particularly when the head is low, the air-liquid interface between the air and the water (refer to an air-liquid interface Y in
However, with the drain pump 8, the outer circumferential edge part of the main blade 92 is disposed at a position lower than the upper end part of the partition part 93b by the forming of the inclined parts 95a, 96a at the outer circumferential part of the main blade 92, which can soften the collision between the air-liquid interface Y and the outer circumferential part of the main blade 92, and it is consequently possible to reduce the operating noise generated by the agitation of the air layer by the main blade 92.
Moreover, because the portion disposed at a position lower than the upper end part of the partition part 93b is the outer circumferential edge part of the main blade 92, which has a high circumferential velocity and greatly affects operating noise: it decreases the effect of softening the collision between the air-liquid interface and the main blade for the inner circumferential part of the main blade 92, which has a comparatively small effect on operating noise, while softening the collision between the air-liquid interface Y and the main blade in the vicinity of the outer circumferential edge part of the main blade 92; and it ensures an effective area by which the main blade 92 can do the work of supplying water. Thereby, a decrease in the discharge flow rate of the drain pump 8 is suppressed, and a drop in pump performance can be kept to a minimum.
In addition, with the drain pump 8, the outer circumferential edge part of the main blade 92 is disposed on the inner circumferential side of the inner circumferential surface of the partition part 93b of the dish part 93, and it is consequently possible to obtain the effect of reliably softening the collision between the air-liquid interface Y and the main blade 92 at the outer circumferential edge part of the main blade 92.
Furthermore, with the drain pump 8, the main blade 92 is formed so that the blade height H1 of the outer circumferential part of the main blade 92 decreases toward the outer circumferential edge part, which makes it easier to ensure an effective area at the outer circumferential part of the main blade 92 by which the main blade 92 can perform the work of supplying water, and it is consequently possible to further suppress a drop in the pump performance of the drain pump 8.
Thus, with this drain pump 8, a drop in the pump performance can be suppressed and the operating noise can be reduced when the head is low. In addition, because such a drain pump 8 having a low operating noise when the head is low is used to discharge the drain water collected in a drain pan 7 of the air conditioner 1, it becomes possible to reduce the noise of the entire air conditioner 1, and problems such as the operating noise of the drain pump becoming a disturbance tend not to occur in cases such as when the flow rate of a fan 4 of the air conditioner 1 is low, or when the interior of the air conditioned room is quiet.
The following explains the experimental results obtained for the drain pump 8 comprising a main blade 92 having the inclined parts 95a, 96a of the present embodiment, and a drain pump 308 comprising a conventional main blade 392, wherein actual measurements were taken of the operating noise with the drain pump unmounted, and of the head, which is one measure of pump performance. Here,
With the drain pump of the conventional example 1, as shown in
However, with the drain pump 8 of the present embodiment, as shown in
Here, it is considered that the operating noise when the water level and the head are low is less than the operating noise of the drain pump of the conventional example 1 because the inclined parts 95a, 96a are formed at the outer circumferential part of the main blade 92, as discussed above. Moreover, it is less than the operating noise of the drain pump of the conventional example 2 because of the difference of the shapes of the inclined parts 95a, 96a formed in the main blade 92 of the drain pump 8 of the present embodiment and the inclined parts formed in the main blade of the drain pump of the conventional example 2. Specifically, this is attributable to the fact that the outer circumferential edge part of each of the inclined parts 95a, 96a formed in the main blade 92 of the drain pump 8 of the present embodiment is disposed at a position lower than the upper end part of the partition part 93b, while the inclined parts 395a, 396a formed in the main blade of the drain pump of the conventional example 2 are formed only in the portion more on the upper side than the upper end part of the partition part 93b. Moreover, with the drain pump 8 of the present embodiment, the outer circumferential edge part of the main blade 92 is disposed on the inner circumferential side of the inner circumferential surface of the partition part 93b of the dish part 93, and it is supposed that this consequently enhances the effect of softening the collision between the air-liquid interface Y and the main blade 92 at the outer circumferential edge part of the main blade 92. In addition, it is considered that the increase in the operating noise when the water level is high and the head is low is attributable to the fact that the inner circumferential part of the main blade 92 is the same shape as the main blade 392 of the drain pumps of the conventional example 1 and the conventional example 2.
Forming the inclined parts 95a, 96a in the main blade 92 slightly reduces the effective area by which the main blade 92 can perform the work of supplying water, but an effective area of the inner circumferential part of the main blade 92 is ensured; consequently, the decrease in the head is kept to a level wherein the head becomes slightly less than the head of the drain pump of the conventional example 1, and a drop in the pump performance of the drain pump 8 is suppressed as much as possible.
Thus, by disposing the outer circumferential edge part of the main blade 92 at a position lower than the upper end part of the partition part 93b as in the drain pump 8 of the present embodiment, a drop in the pump performance is suppressed, and the effect was confirmed that the operating noise can be effectively reduced at times of low head, and particularly when a low head operating condition overlaps with a low water level operating condition.
The impeller 182 principally comprises: the shaft part 91 coupled to the drive shaft of the motor 83; a main blade 192 disposed inside the main body part 84a of the pump casing 81; an auxiliary blade 94 disposed on the lower side of the main blade 192; and the disc shaped dish part 93 disposed between the main blade 192 and the auxiliary blade 94, and having an opening 93a comprising an annular through hole in the center. Here, excepting the main blade 192, the explanation of the impeller 182 is abbreviated because its constitution is the same as the conventional impeller 382.
The main blade 192 comprises, for example: four first blades 195 extending radially from the outer circumferential surface of the shaft part 91; and four second blades 196 extending radially from the outer circumferential edge part of the opening 93a of the dish part 93, and disposed between the first blades 195 in the circumferential direction. Furthermore, the number of first blades 195 and second blades 196 that constitute the main blade 192 is not limited to the abovementioned number, and various numbers thereof can be chosen.
Each first blade 195 is formed so that the height position of the upper end part of the first blade 195 (hereinafter, as shown in
With a drain pump 108 having a main blade 192 wherein such inclined parts 195a, 196a are formed, the air layer expands circularly concentric with the shaft part 91 of the main blade 192 as the water level h falls, the same as the inside of the main body part 84a of the conventional drain pump 308. Particularly when the head is low, the air-liquid interface between the air and the water (refer to an air-liquid interface Y in
However, with the drain pump 108, by forming the inclined parts 195a, 196a over the entire main blade 192, the blade height H1 is lower at the outer circumferential part than at the inner circumferential part, which can soften the collision between the air-liquid interface Y and the outer circumferential part of the main blade 192, and it is consequently possible to reduce the operating noise generated by the agitation of the air layer by the main blade 192.
Moreover, as the water level h rises, the air layer shrinks (refer to an air-liquid interface X in
Thus, with this drain pump 108, it is possible to soften the collision between the air-liquid interface and the main blade 192 in any of these cases: the case where, when the head is low, the air-liquid interface between the air and the water expands to the outer circumferential part, where the circumferential velocity is high; and the case where, when the head is low, the air-liquid interface is positioned at the inner circumferential part, more so in the case when the water level is rising than when the water level is low; consequently, the operating noise can be reduced when the head is low even when the position of the air-liquid interface varies due to variations in the water level. In addition, because such a drain pump 108 having a low operating noise when the head is low is used to discharge the drain water collected in the drain pan 7 of the air conditioner 1, it becomes possible to reduce the noise of the entire air conditioner 1, and problems such as the operating noise of the drain pump becoming a disturbance tend not to occur in cases such as when the flow rate of the fan 4 of the air conditioner 1 is low, or when the interior of the air conditioned room is quiet.
The following explains, referencing
With the drain pump 108 of the present embodiment, as shown in
Here, it is considered that the operating noise when the water level and the head are low is less than the operating noise of the drain pump of the conventional example 1 because the inclined parts 195a, 196a are formed at the outer circumferential part of the main blade 192, as discussed above. In addition, it is considered that the operating noise is greater than the operating noise of the drain pump 8 of the first embodiment because: the inclination of the inclined parts 195a, 196a is gentler than the inclination of the inclined parts 95a, 96a of the first embodiment; the outer circumferential edge part of the main blade 192 is not disposed at a position lower than the upper end part of the partition part 93b; and the effect of softening the collision between the air-liquid interface and the main blade 192 at the outer circumferential part of the main blade 192 is somewhat less than that of the inclined parts 95a, 96a of the first embodiment. In addition, it is considered that the operating noise is lower than the operating noise of the drain pump of the conventional example 2 when the water level and the head are low because the inclined parts 195a, 196a are formed not only at the outer circumferential part of the main blade 192, but over the entire main blade 192. Furthermore, it is considered that the operating noise is reduced when the water level is high and the head is low because: the inclined parts 195a, 196a are formed over the entire main blade 92; and the effect of softening the collision between the air-liquid interface and the main blade 192 at the inner circumferential part of the main blade 192 is obtained, unlike the main blade of the drain pump of the conventional examples 1 and 2, and unlike the main blade 92 of the drain pump 8 of the first embodiment.
Forming the inclined parts 195a, 196a in the main blade 192 slightly reduces the effective area by which the main blade 192 can perform the work of supplying water, but, as a result of forming the inclined parts 195a, 196a over the entire main blade 92, an effective area of the outer circumferential part of the main blade 192 is ensured; consequently, on par with the drain pump 8 of the first embodiment, the decrease in the head is kept to a level wherein the head becomes slightly less than the head of the drain pump of the conventional example 1, and a drop in the pump performance of the drain pump 108 is suppressed as much as possible.
Thus, by forming the inclined parts 195a, 196a over the entire main blade 192 as in the drain pump 108 of the present embodiment, a drop in the pump performance is suppressed, the effect wherein the operating noise can be reduced not only when the head and the water level are low, but also when the head is low and the water level is high, was confirmed; as a result, it was seen that the effect of reducing variations in the operating noise due to variations in the head and water level was obtained.
The impeller 282 principally comprises: the shaft part 91 coupled to the drive shaft of the motor 83; the auxiliary blade 94 disposed on the lower side of a main blade 292; and the disc shaped dish part 93 disposed between the main blade 292 and the auxiliary blade 94, and having the opening 93a comprising an annular through hole in the center. Here, excepting the main blade 292, the explanation of the impeller 282 is abbreviated because its constitution is the same as the conventional impeller 382.
The main blade 292 comprises, for example: four first blades 295 extending radially from the outer circumferential surface of the shaft part 91; and four second blades 296 extending radially from the outer circumferential edge part of the opening 93a of the dish part 93, and disposed between the first blades 295 in the circumferential direction. Furthermore, the number of first blades 295 and second blades 296 that constitute the main blade 292 is not limited to the abovementioned number, and various numbers thereof can be chosen.
Because a jagged part 295a is formed, the height position of the upper end part of each first blade 295 (hereinafter, as shown in
In the present embodiment, the jagged parts 295a, 296a are right triangle waveform shaped portions, and the outermost circumferential part thereof (hereinafter, referred to as inclined parts 295b, 296b) is shaped inclined so that the blade height H1 decreases toward the outer circumferential edge part. These inclined parts 295b, 296b are formed so that one part of the outer circumferential part of each first blade 295 and each second blade 296 is notched, and the outer circumferential edge part thereof is disposed at a position lower than the upper end part of the partition part 93b (specifically, the dish height H2).
In addition, the inclined parts 295b, 296b are notched so that the outer diameter of each first blade 295 and each second blade 296 is shorter than an external dimension D of the partition part 93b, and further is shorter than a diameter d of the inner circumferential surface of the partition part 93b. Consequently, the outer circumferential edge part of each first blade 295 and each second blade 296 is disposed on the inner circumferential side of the inner circumferential surface of the partition part 93b. Furthermore, the shape of the jagged parts 295a, 296a is not limited to those in the present embodiment, and other shapes, such as a rectangular waveform shape and a sine waveform shape, are also applicable.
With a drain pump 208 provided with a main blade 292 wherein jagged parts 295a, 296a having such inclined parts 295b, 296b are formed, the air layer expands circularly concentric with the shaft part 91 of the main blade 292 as the water level h falls, the same as the inside of the main body part 84a of the conventional drain pump 308. Particularly when the head is low, the air-liquid interface between the air and the water (refer to an air-liquid interface Y in
However, with the drain pump 208, the outer circumferential edge part of the main blade 292 is disposed at a position lower than the upper end part of the partition part 93b by the forming of the jagged parts 295a, 296a (specifically, the inclined parts 295b, 296b) at the outer circumferential part of the main blade 292, which can soften the collision between the air-liquid interface Y and the outer circumferential part of the main blade 292, and it is consequently possible to reduce the operating noise generated by the agitation of the air layer by the main blade 292, the same as the drain pump 8 as the first embodiment.
Moreover, as the water level h rises, the air layer shrinks (refer to the air-liquid interface X in
Furthermore, because such a drain pump 208 having a low operating noise when the head is low is used to discharge the drain water collected in the drain pan 7 of the air conditioner 1, it becomes possible to reduce the noise of the entire air conditioner 1, and problems such as the operating noise of the drain pump becoming a disturbance tend not to occur in cases such as when the flow rate of the fan 4 of the air conditioner 1 is low, or when the interior of the air conditioned room is quiet.
The above explained embodiments of the present invention based on the drawings, but the specific constitution is not limited to these embodiments, and it is understood that variations and modifications may be effected without departing from the spirit and scope of the invention.
With the main blade 92 that constitutes the impeller 82 of the drain pump 8 of the first embodiment, the outer circumferential edge part of each first blade 95 and each second blade 96 is disposed on the inner circumferential side of the inner circumferential surface of the partition part 93b due to the notching so that the inclined parts 95a, 96a are shorter than the diameter d of the inner circumferential surface of the partition part 93b; however, as shown in
Even in this case, because the outer circumferential edge part of each first blade 95 and each second blade 96 is disposed at a position lower than the upper end part of the partition part 93b, it is supposed that the operating noise when the head is low can be reduced more than the drain pumps of the conventional examples 1 and 2.
In addition, with the main blade 92 that constitutes the impeller 82 of the drain pump 8 of the first embodiment, the inclined parts 95a, 96a are shaped inclined so that the blade height H1 decreases linearly toward the circumferential edge part; however, as shown in
Even in this case, it is supposed that the operating noise when the head is low can be reduced more than the drain pumps of the conventional examples 1 and 2 because the outer circumferential edge part of each first blade 95 and each second blade 96 is disposed at a position lower than the upper end part of the partition part 93b.
With the main blade 192 that constitutes the impeller 182 of the drain pump 108 of the second embodiment, the inclined parts 195a, 196a are formed so that the blade height decreases from the inner circumferential edge part of each first blade 195 and each second blade 196 toward the outer circumferential edge part (specifically, the upper end part of the outer circumferential edge part of the partition part 93b), and the collision between the air-liquid interfaces X, Y and the main blade 192 over the entire main blade 192 can reliably be softened, thus reducing the operating noise when the head is low (refer to
In this case, it is supposed that the operating noise can be further reduced when the head and the water level are low because the effect of softening the collision between the air-liquid interface and the main blade 92 at the outer circumferential part of the main blade 92 can be enhanced.
With the main blade 292 that constitutes the impeller 282 of the drain pump 208 of the third embodiment, the inclined parts 295b, 296b are formed by notching one part of the outer circumferential part of each first blade 295 and each second blade 296 so that the outer diameter of each first blade 295 and each second blade 296 is shorter than the external dimension D of the partition part 93b, which enables the reliable softening of the collision between the air-liquid interface Y and the main blade 292 at the outer circumferential part of the main blade 292, thereby significantly reducing the operating noise when the head and the water level are low (refer to
In so doing, the effect of softening the collision between the air-liquid interface and the main blade 292 at the outer circumferential part of the main blade 292 decreases; nevertheless, it is supposed that it will obtain the effect of reducing the operating noise on par with the drain pump 108 of the second embodiment.
Using the present invention enables a reduction in the operating noise of the drain pump when the head is low.
Number | Date | Country | Kind |
---|---|---|---|
2003-406758 | Dec 2003 | JP | national |
2004-050132 | Feb 2004 | JP | national |
This application is a continuation application of U.S. patent application Ser. No. 10/548,430 filed on Sep. 8, 2005, now U.S. Pat. No. 7,435,048, which is a National Stage application of International Patent Application No. PCT/JP2004/017773 filed on Nov. 30, 2004. The entire disclosure of U.S. patent application Ser. No. 10/548,430 is hereby incorporated herein by reference. This application claims priority to Japanese Patent Application Nos. 2003-406758 and 2004-050132 respectively filed on Dec. 5, 2003 and Feb. 25, 2004. The entire disclosures of Japanese Patent Application Nos. 2003-406758 and 2004-050132 are hereby incorporated herein by reference.
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Number | Date | Country | |
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Number | Date | Country | |
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Parent | 10548430 | US | |
Child | 12176112 | US |