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(11) | EP 1 647 716 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Drain pump |
| (57) The invention provides a drain pump of an air conditioner capable of preventing return
water from splashing toward a motor when the motor stops. A drain pump 1a comprises
a pump body 10 including a pump chamber 16, an inlet port 12 and an outlet port 14,
and a lid member 130. A boss portion 132 of a lid member has an opening 134 through
which a shaft 52 of a rotary vane 50 within the pump chamber 16 is projected. An output
shaft 64 of the motor 60 within the motor casing 140 is press-fit to the shaft portion
52. When the motor 60 is stopped, the water inside the exhaust hose 18 flows back
into the pump chamber 16 and is spurted through the opening 134. An outer circumference
wall 144 of an opening 142 of the output shaft 64 of the motor casing 140 is tapered
so as to prevent the spurted water from entering the motor.
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BACKGROUND OF THE INVENTION
Field of the invention
[0001] The present invention relates to a drain pump for draining condensed water or the like in an indoor equipment of an air conditioner disposed on a ceiling of a room or the like.
Description of the related art
[0003] The drain pump denoted as a whole by reference number 1 has a pump body 10. The pump body 10 has an inlet port 12 extending downward and facing a drain pan for receiving the drain water, an outlet port 14 extending horizontally from the body, and a pump chamber 16 disposed between the inlet and outlet ports. The outlet port 14 is connected to an exhaust hose 18.
[0004] The body 10 is formed of resin, and a lid member 30 is fit thereto. A seal member 38 is provided between the body 10 and the lid member 30.
[0005] An electric motor 60 is provided inside a motor casing 40 formed integrally to a leg portion 42 provided on the lid member 30. Power is fed to the electric motor 60 through a cord 62.
[0006] The output shaft 64 of a motor 60 is supported by a bearing 66, and the end of the shaft is press-fit to a hole with a bottom formed to the shaft portion 52 of the rotary vane 50.
[0007] The rotary vane 50 has a shaft portion 52 projecting through an opening 34 at an inner side of a center boss portion 32 of the lid member 30, and a large-diameter vane 54 connected to the shaft portion 52. The outer circumference of the large-diameter vane 54 is covered by a ring member 58 and rotates within the pump chamber 16. The lower portion of the large-diameter vane 54 is connected via a tapered portion 55 to a small-diameter vane 56. The small-diameter vane 56 rotates within an inlet portion 12 of the pump body 10.
[0008] When the electric motor 60 is activated, the water W1 within the drain pan is pumped up by the small-diameter vane 56 and given centrifugal force by the large-diameter vane 54, then discharged to the exterior through the hose 18.
[0009] When the motor 60 stops, the water W2 remaining inside the hose 18 returns through outlet port 14 into the pump chamber 16.
[0010] Since the inlet port 12 of the pump body is sealed by the water inside the drain pan, the water W2 returning into the pump chamber 16 is spurted toward the motor 60 through the gap formed between the opening 34 of the lid member 30 and the shaft portion 52 of the rotary vane 50.
[0011] A disk-shaped drain board 70 is provided on the output shaft 64 of the motor in order to prevent the spurted water W2 from splashing toward the bearing 66 of the motor 60.
[0012] The space between the shaft portion 52 of the rotary vane 50 and the opening of the lid member 30 is indispensable in this type of drain pump.
[0013] This type of drain pump is disclosed in Japanese Patent Application Laid-Open Publication No. 2000-213770 (patent document 1).
[0014] Further, Japanese Patent Application Laid-Open Publication No. 2002-242873 (patent document 2) discloses a drain pump eliminating the drain board.
SUMMARY OF THE INVENTION
[0015] The object of the present invention is to provide a drain pump with reduced number of components and solving the problem of the opening being blocked.
[0016] The drain pump of an air conditioner according to the present invention comprises, as basic means, a pump body having a pump chamber, an inlet port extending downward from the pump chamber and an outlet port extending horizontally from the pump chamber, a lid member covering an opening of the pump body, a rotary vane disposed inside the pump chamber, a motor casing provided on the lidmember, an electricmotor disposed inside the motor casing, and an output shaft of the motor press-fit to a shaft member of the rotary vane.
[0017] Further, the lid member has an opening through which the shaftmemberof the rotary vane passes, and an outer circumference wall of the opening through which the motor output shaft of the motor casing passes is shaped to have a tapered portion narrowed toward the rotary vane.
[0018] Moreover, the lid member has an opening through which the shaft member of the rotary vane passes, and an outer circumference wall of the opening through which the motor output shaft of the motor casing passes can be shaped to have a circular portion extending toward the rotary vane and a narrowed tapered portion connected to the circular portion.
[0019] According to another aspect of the invention, the lid member has an opening through which the shaft member of the rotary vane passes, and an outer circumference wall of the opening through which the motor output shaft of the motor casing passes is shaped to have a circular portion extending toward the rotary vane and a narrow cylindrical portion connected to the circular portion, or the lid member can have a tapered bore narrowing toward a motor output shaft and a cylindrical bore connected to the tapered bore through which the shaft member of the rotary vane passes.
[0020] The drain pump according to the present invention having the means mentioned above does not require a drain board. Further, water can be prevented from splashing toward the motor, and the problems that may occur from water entering the motor can be prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021]
FIG. 1 is an explanatory view showing an embodiment of a drain pump according to the present invention;
FIG. 2 is an enlarged view showing the relevant portion of the embodiment of the present drain pump;
FIG. 3 is an explanatory view showing another embodiment of the present drain pump;
FIG. 4 is an explanatory view showing yet another embodiment of the present drain pump;
FIG. 5 is an explanatory view showing yet another embodiment of the present drain pump;
FIG. 6 is an explanatory view showing yet another embodiment of the present drain pump;
FIG. 7 is an explanatory view showing yet another embodiment of the present drain pump; and
FIG. 8 is an explanatory view of a drain pump according to the prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] FIG. 1 is an explanatory view showing a first embodiment of the present invention, and FIG. 2 is an explanatory view showing the relevant portion thereof.
[0023] A drain pump 1a according to the present embodiment has abasic structure similar to that of FIG. 8, so the maj or components are denoted by the same reference numbers and the detailed explanations thereof are omitted.
[0024] According to the drain pump 1a of the present embodiment, similar to the aforementioned drain pump, a space is formed between an opening 134 of a boss portion 132 of a lid member 130 and a shaft portion 52 of a rotary vane 50. An output shaft 64 of an electric motor 60 is press-fit to the shaft portion 52 of the rotary vane, but according to the present embodiment, there is no disk-shaped drain board equipped to the pump. The shape of an outer circumference wall of an opening 142 of a motor casing 140 through which the output shaft 64 of the motor passes is shaped into a tapered portion 144 narrowed toward the rotary vane 50.
[0025] When the electric motor 60 is activated and the rotary vane 50 starts pumping up water, the water within the inlet port 12 is lifted via a small-diameter vane 56 and givencentrifugal force by a large-diameter vane 54. At this time, since air is introduced through the opening 134 of the lid member 130, the water circling inside the pump chamber 16 is shaped to have a substantiallyparabolic cross-section with a free surface formed at the center thereof, and is discharged through an outlet port 14.
[0026] Return water W2 from the exhaust hose generated when the drain pump stops spurts through the opening 134 and splashes toward the motor casing 140, but collides against the tapered portion 144 of the casing 140 and splashes outward. Therefore, the water will not enter the opening 142 at the outer side of the motor output shaft 64. Thus, the entrance of water to the bearing 66 can be prevented.
[0028] A drain pump 1b of the present embodiment is equipped with a lid member 230 similar to that of the embodiment illustrated in FIG. 1.
[0029] The shape of the outer circumference wall of an opening 242 of a motor output shaft 64 of a motor casing 240 is formed to have a circular portion 244 and a narrowed tapered portion 246 connected to the circular portion 244.
[0030] According to this configuration, the return water spurted through the opening 234 of the lid member 230 will not splash toward the motor output shaft 64.
[0032] A drain pump 1c according to the present embodiment is equipped with a lid member 330 similar to that of the embodiment illustrated in FIG. 3.
[0033] The shape of the outer circumference wall of an opening 342 of a motor output shaft 64 of a motor casing 340 is formed to have a circular portion 344 and a narrow cylindrical portion 346 connected to the circular portion 344.
[0034] According to this configuration, the return water spurted through the opening 334 of the lid member 330 will not splash toward the motor output shaft 64.
[0036] A drain pump 1d according to the present embodiment includes a motor casing 440 similar to that of the embodiment illustrated in FIG. 4. That is, the shape of the outer circumference wall of an opening 442 of a motor output shaft 64 of a motor casing 440 is formed to have a circular portion 444 and a narrow cylindrical portion 446 connected to the circular portion 444.
[0037] On the other hand, the inner diameter of a boss portion 432 of a lidmember 430 has a narrow cylindrical bore 434 opening toward the motor casing and a tapered bore 436 connected to the cylindrical bore 434.
[0038] According to this configuration, the return water spurted through the opening 434 of the lid member 430 will not splash toward the motor output shaft 64.
[0040] A drain pump 1e according to the present embodiment includes a motor casing 540 similar to that of the embodiment illustrated in FIG. 4. That is, the shape of the outer circumference wall of an opening 542 of a motor output shaft 64 of a motor casing 540 is formed to have a concaved circular portion.
[0041] On the other hand, the inner diameter of a boss portion 532 of a lid member 530 is formed as a cylindrical bore 536.
[0042] According to this configuration, the return water spurted through the opening 536 of the lid member 530 will not splash toward the motor output shaft 64.
[0044] A drain pump 1f according to the present embodiment has an inner diameter size b of an inner diameter 642 of an opening 644 of the motor output shaft 64 of a motor casing 640 and an outer diameter size a of the shaft member 52 of the rotary vane projected through a boss portion 632 of the lid member 630 which satisfies the following relationship: b ≤ a
a pump body having a pump chamber, an inlet port extending downward from the pump chamber and an outlet port extending horizontally from the pump chamber;
a lid member covering an opening of the pump body;
a rotary vane disposed inside the pump chamber;
a motor casing provided on the lid member;
an electric motor disposed inside the motor casing; and
an output shaft of the motor press-fit to a shaft member of the rotary vane; wherein
the lid member has an opening through which the shaft member of the rotary vane passes, and an outer circumference wall of the opening through which the motor output shaft of the motor casing passes is shaped to have a tapered portion narrowed toward the rotary vane.
a pump body having a pump chamber, an inlet port extending downward from the pump chamber and an outlet port extending horizontally from the pump chamber;
a lid member covering an opening of the pump body;
a rotary vane disposed inside the pump chamber;
a motor casing provided on the lid member;
an electric motor disposed inside the motor casing; and
an output shaft of the motor press-fit to a shaft member of the rotary vane; wherein
the lid member has an opening through which the shaft member of the rotary vane passes, and an outer circumference wall of the opening through which the motor output shaft of the motor casing passes is shaped to have a circular portion extending toward the rotary vane and a narrowed tapered portion connected to the circular portion.
a pump body having a pump chamber, an inlet port extending downward from the pump chamber and an outlet port extending horizontally from the pump chamber;
a lid member covering an opening of the pump body;
a rotary vane disposed inside the pump chamber;
a motor casing provided on the lid member;
an electric motor disposed inside the motor casing; and
an output shaft of the motor press-fit to a shaft member of the rotary vane; wherein
the lid member has an opening through which the shaft member of the rotary vane passes, and an outer circumference wall of the opening through which the motor output shaft of the motor casing passes is shaped to have a circular portion extending toward the rotary vane and a narrow cylindrical portion connected to the circular portion.
a pump body having a pump chamber, an inlet port extending downward from the pump chamber and an outlet port extending horizontally from the pump chamber;
a lid member covering an opening of the pump body;
a rotary vane disposed inside the pump chamber;
a motor casing provided on the lid member;
an electric motor disposed inside the motor casing; and
an output shaft of the motor press-fit to a shaft member of the rotary vane; wherein
the lid member has a tapered bore narrowing toward a motor output shaft and a cylindrical bore connected to the tapered bore through which the shaft member of the rotary vane passes; and
an outer circumference wall of the opening through which the motor output shaft of the motor casing passes is shaped to have a circular portion extending toward the rotary vane and a narrow cylindrical portion connected to the circular portion.
a pump body having a pump chamber, an inlet port extending downward from the pump chamber and an outlet port extending horizontally from the pump chamber;
a lid member covering an opening of the pump body;
a rotary vane disposed inside the pump chamber;
a motor casing provided on the lid member;
an electric motor disposed inside the motor casing; and
an output shaft of the motor press-fit to a shaft member of the rotary vane; wherein
the lid member has an opening through which the shaft member of the rotary vane passes, and an outer circumference wall of the opening through which the motor output shaft of the motor casing passes is shaped to have a concaved circular portion extending toward the rotary vane.
a pump body having a pump chamber, an inlet port extending downward from the pump chamber and an outlet port extending horizontally from the pump chamber;
a lid member covering an opening of the pump body;
a rotary vane disposed inside the pump chamber;
a motor casing provided on the lid member;
an electric motor disposed inside the motor casing; and
an output shaft of the motor press-fit to a shaft member of the rotary vane; wherein
the lid member has an opening through which the shaft member of the rotary vane passes, wherein an inner diameter size b of the opening portion through which the motor output shaft of the motor casing passes and the outer diameter size a of the shaft member of the rotary vane satisfy the following relation: b ≤ a; and
the distance between the inner diameter of the opening portion and the motor output shaft at one side thereof is within the range of 0.2 through 2.5 mm.