US20130074554A1

US20130074554A1 - Drain pump and washing machine having the same

Info

Publication number: US20130074554A1
Application number: US13/630,958
Authority: US
Inventors: Kwang Min Chun; Jung Sang Choi
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2011-09-28
Filing date: 2012-09-28
Publication date: 2013-03-28
Also published as: KR20130034311A; EP2574695A1; CN103031699A; EP2574695B1; CN103031699B

Abstract

A drain pump capable of easily discharging air in the drain pump, and a washing machine having the same. The drain pump includes a washing water inlet compartment, a drain pump compartment configured to pump washing water contained in the washing water inlet compartment to an outside, a suction port provided between the washing water inlet compartment and the drain pump compartment to move the washing water from the washing water inlet compartment to the drain pump compartment, a drain line to connect the drain pump compartment to an outside to discharge the washing water, and an air outlet port provided on the drain pump compartment to discharge air contained in the drain pump compartment to an outside, wherein the air outlet port is connected to the drain line.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of Korean Patent Applications No. 10-2011-0098255, filed on Sep. 28, 2011 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND

1. Field
Embodiments of the present disclosure relate to a washing machine, and more particularly, to a washing machine provided with a drain pump configured to pump the washing water stored in a tub.
2. Description of the Related Art
A washing machine designed to wash laundry by use of electric power, in general, includes a tub to accommodate a washing water, a rotating tub rotatably installed at an inside the tub, a driving apparatus to rotate the rotating tub, a water supply apparatus to supply water to an inside the tub, and a drain pump to forcedly drain water in the tub.
In general, the drain pump includes a pump case provided with a washing water inlet compartment to accommodate washing water and a drain pump compartment, and a pumping motor installed at one side of the pump case. The interior of the pump case is provided at an inside thereof with a pump filter to filter foreign substance contained in the washing water. The drain pump compartment is provided with an impeller configured to be rotated by the pumping motor.
When the impeller is rotated by the pumping motor, the washing water in the tub is introduced into the washing water inlet compartment. The washing water introduced into the washing water inlet compartment passes through the filter, and is withdrawn into the drain pump compartment. The washing water reached to the drain pump compartment is forcedly discharged to an outside the drain pump by the impeller.
During such a pumping process, air may be introduced into an inside the drain pump together with the washing water. If the air is introduced into an inside the pump, the performance of the impeller installed in the drain pump compartment may be degraded, and thus a drain fault may occur or an abnormal noise may be generated.
In general, in order to discharge the air introduced into an inside the drain pump to an outside, an air outlet port is provided. The air outlet port is connected to the tub through a hose. Accordingly, the air at an inside the pump is discharged to a side of the tub through the air outlet port and the hose.
Since the region where air stays in the drain pump is an upper part of the drain pump compartment, the position of the air outlet port is needed to be adjusted so as to discharge the air.
In addition, there is a need for the air to be discharged to other side than the tub provided at an upper side of the drain pump so as to enhance the efficiency of discharging air.

SUMMARY

Therefore, it is an aspect of the present disclosure to provide a drain pump capable of easily discharging air thereof to an outside, and a washing machine having the same.
Additional aspects of the disclosure will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the disclosure.
In accordance with one aspect of the present disclosure, a drain pump includes a washing water, a drain pump, a suction port, a drain line and an air outlet port. The drain pump compartment may be configured to pump washing water contained in the washing water inlet compartment to an outside. The suction port may be provided between the washing water inlet compartment and the drain pump compartment to move the washing water from the washing water inlet compartment to the drain pump compartment. The drain line may connect from the drain pump compartment to an outside to discharge the washing water. The air outlet port may be provided on the drain pump compartment to discharge air contained in the drain pump compartment to an outside. The air outlet port is connected to the drain line.
The air naturally may flow from the air outlet port to the drain line due to the difference in pressure between the drain pump compartment and the drain line.
The air outlet port may protrude at an upper portion of the drain pump compartment.
The drain pump may further include an air inlet port provided on the drain line, wherein the air outlet port is connected to the air inlet port.
The drain pump may further include an air passage to connect the air outlet port to the air inlet port.
The air passage may include a rubber hose.
The air inlet port may be integrally formed with the drain line.
The air inlet port may be separately formed with the drain line and coupled to the drain line.
The drain line may include a drain passage connected to the drain pump compartment, and an air passage connected to the air outlet port.
The air passage may be branched from the drain passage.
The air passage may be integrally formed with the drain passage.
The air passage may have a diameter smaller than a diameter of the drain passage.
The drain line may include an outlet port protruded at the pump case, and a drain hose including one end connected to the outlet port and the other end extended to an outside.
In accordance with another aspect of the present disclosure, a drain pump includes a pump case, a pumping motor, a drain hose, an air outlet port, an air inlet port, and an air passage. The pump case may be configured to accommodate washing water. The pumping motor may be provided at one end of the pump case to pump the washing water to an outside. The drain hose may be connected to the pump case while being adjacent to the pumping motor such that the washing water pumped by the pumping motor flows to an outside. The air outlet port may be formed at a side of an upper portion of the pump case to discharge air, the side adjacent to the pumping motor. The air inlet port may protrude at the drain hose. The air passage may connect the air outlet port to the air inlet port.
The air may naturally flow from the air outlet port to the air inlet port due to the difference in pressure between the drain hose and the pump case, the difference in pressure caused by the difference in velocity between the washing water flowing in the drain hose and the washing water flowing in the pump case.
In accordance with another aspect of the present disclosure, a drain pump includes a pump case, a pumping motor, a drain hose, an air outlet port and an air passage. The pump case may be configured to accommodate washing water. The pumping motor may be provided at a portion of the pump case to generate a driving force to allow the washing water to be forcedly discharged to an outside. The drain hose may be connected to the portion of the pump case, at which the pumping motor is provided, to guide the washing water to an outside. The air outlet port may protrude at an upper side of the portion of the pump case, at which the pumping motor is provided, to discharge air. The air passage may have one end connected to the air outlet port and the other end connected to the drain hose.
The air passage may be integrally formed with the drain hose.
In accordance with another aspect of the present disclosure, with respect to a washing machine provided with a tub, a drain pump to pump washing water in the tub, and a drain hose configured to allow the washing water pumped by the drain pump to flow therethrough for drainage, the drain pump includes a washing water inlet compartment, a drain pump compartment, an air outlet port, and an air passage. The washing water inlet compartment may be configured to enable the washing water to be introduced thereinto from the tub. The drain pump compartment may be provided with a suction port to draw the washing water in the washing water inlet compartment, and an outlet port including a drain hose, which is configured to drain the washing water, connected thereto. The air outlet port may be protruded at an upper portion of the drain pump compartment. The air passage may connect the air outlet port to the drain hose.
The drain hose may include an air inlet port protruded at the drain hose, wherein the air passage may have one end connected to the air outlet port and the other end connected to the air inlet port.
The other end of the air passage may be integrally formed with the drain hose.
In accordance with another aspect of the present disclosure, a washing machine includes a cabinet, a tub, a drain pump, a drain line and an air passage. The tub may be disposed at an inside the cabinet to accommodate washing water. The drain pump may be disposed at a lower portion of the tub to drain the washing water contained in the tub. The drain line may be connected to the drain pump to guide the washing water, which is pumped by the drain pump, to an outside the cabinet. The air passage may connect the drain pump to the drain line to discharge air contained in the drain pump.
The drain pump may include an air outlet port protruded upward, at the drain pump, and the drain line comprises an air inlet port protruded upward, at the drain line, wherein one end of the air passage may be connected to the air outlet port and the other end of the air passage is connected to the air inlet port.
The drain pump may include an air outlet port protruded upward, at the drain pump, wherein one end of the air passage is connected to the air outlet port and the other end of the air passage is integrally formed with the drain line.
According to embodiments of the present disclosure, the air outlet port is formed at an upper side of the drain pump compartment, and the air outlet port is connected to the drain hose to easily remove the air in the drain pump.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects of the disclosure will become apparent and more readily appreciated from the following description of embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a cross-sectional view illustrating the configuration of a washing machine in accordance with an embodiment of the present disclosure.

FIG. 2 is a perspective view illustrating a drain pump and a drain hose of the washing machine in accordance with an embodiment of the present disclosure.

FIG. 3 is a perspective view illustrating the drain pump of the washing machine of FIG. 1.

FIG. 4 is a view illustrating a pump case of the drain pump of FIG. 3.

FIG. 5 is a view illustrating the drain hose of FIG. 3.

FIG. 6 is a cross-sectional view illustrating the pump case taken along line I-I.

FIG. 7 is a perspective view illustrating a drain pump in accordance with another embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
Referring to FIGS. 1 and 2, a washing machine 1 includes a cabinet 10 forming the exterior of the washing machine 1, a tub 20 disposed at an inside the cabinet 10, a rotating tub 30 rotatably disposed at the tub 20, and a motor 40 to drive the rotating tub 30.
The cabinet 10 includes a plurality of frames 10 a, 10 b, and 10 c including a front side frame 10 a forming the front surface of the cabinet 10, lateral side frames 10 c forming the lateral surfaces and the rear surface of the cabinet 10, and a lower side frame 10 b framing the lower surface of the cabinet 10.
The lower side frame 10 b is provided at a front side thereof with a predetermined portion that is bent upward to be coupled to the front side frame 10 a.
The cabinet 10 is provided at a front surface thereof with an inlet 11 through which a laundry is input into the rotating tub 30. The inlet 11 is open/closed by the door 12 installed at the front surface of the cabinet 10.
The tub 20 is supported by a damper 25. The damper 25 connects the bottom surface of an inner side of the cabinet 10 to an outer surface of the tub 20.
A water supply pipe 50 to supply the tub 20 with washing water is installed at an upper portion of the tub 20. One side of the water supply pipe 50 is connected to an outside water supply source (not shown), and the other side of the water supply pipe 50 is connected to a detergent dispensing apparatus 52.
The detergent dispensing apparatus 52 is connected to the tub 20 through a connection pipe 54. The water supplied through the water supply pipe 50 is supplied to an inside the tub 20 together with detergent via the detergent dispensing apparatus 52.
The rotating tub 30 includes a cylindrical part 31, a front side panel 32 disposed at a front side of the cylindrical part 31, and a rear side panel 33 disposed at a rear side of the cylindrical part 31. The front side panel 32 has an opening 32 a through which a laundry is input/withdrawn. The rear side panel 33 is connected to a driving shaft 41 configured to transmit a driving force of the motor 40.
A plurality of through-holes 34 is formed through a circumference of the rotating tub 30 for circulation of the washing water, so that an inner space of the rotating tub 30 communicates with an inner space of the tub 20.
A plurality of lifters 35 is installed at an inner circumferential surface of the rotating tub 30 to enable the ascending and descending of laundry when the rotating tub 30 rotates.
The driving shaft 41 has one end connected to the rear side panel 33 of the rotating tub 30, and the other end extended to an outside the tub 20. When the motor 40 drives the driving shaft 41, the rotating tub 30 connected to the driving shaft 41 rotates about the driving shaft 41.
A bearing housing 42 rotatably supporting the driving shaft 41 is installed at a rear wall of the tub 20. The bearing housing 42 may be formed using an aluminum alloy. The bearing housing 42 may be inserted into the rear wall of the tub 20 when the tub 20 is formed through an injection molding. A plurality of bearings 43 is installed between the bearing housing 42 and the driving shaft 41 to enable a smooth rotation of the driving shaft 41.
During a washing cycle, the motor 40 rotates the rotating tub 30 in reverse/forward directions at a low speed. As the rising and falling of the laundry at an inside the rotating tub 30 is repeated, the dirt on the laundry is removed.
During a spin-dry cycle, the motor 40 rotates the rotating tub 30 in one direction at a high speed, so that water is separated from the laundry by a centrifugal force acting on the laundry.
A drain pump 100 to pump the washing water stored in the tub 20 is installed at a lower portion at an inside of the cabinet 10. The drain pump 100 is connected to the outside through a drain hose 60.
The drain pump 100 is exposed to the front surface of the cabinet 10 through a through-hole 13 that is provided at a portion where the protrusion of the lower side frame 10 b overlaps a lower end of the front side frame 10 a.
The drain hose 60 is coupled to an inner side of the cabinet 10 by a hose wire 92 and a hose holder 91 while preventing the drain hose 60 from interfering with other components at an inside the cabinet 10. The drain hose 61 is guided to an outside by a hose guide 90.
FIG. 3 is a perspective view illustrating the drain pump of the washing machine of FIG. 1. FIG. 4 is a view illustrating a pump case of the drain pump of FIG. 3. FIG. 5 is a view illustrating the drain hose of FIG. 3. FIG. 6 is a cross-sectional view illustrating the pump case taken along line I-I. The pump case illustrated on the FIG. 6 has the pump filter omitted therefrom.
Referring to FIGS. 3 to 6, a drain pump 100 a includes a washing water inlet compartment 111, a pump case 110 including a drain pump compartment 120 and a bubble generating compartment 130, and a pump filter 140 configured to be inserted into the washing water inlet compartment 111. The drain pump compartment 120 and the bubble generating compartment 130 are disposed opposite to each other while interposing the washing water inlet compartment 111 thereinbetween.
A bubble generating motor 131 is disposed at a side of the pump case 110 adjacent to the bubble generating compartment 130. A circulation impeller 132 is connected to the bubble generating motor 131. The circulation impeller 132 is disposed at an inside the bubble generating compartment 130.
The bubble generating compartment 130 is provided, at an upper portion of the bubble generating compartment 130, with a circulation port 134 that protrudes upward to circulate the washing water 20 to an inside of the tub 20. A circulation pipe 80 is connected to the circulation port 134.
As the circulation impeller 132 is rotated by the bubble generating motor 131, the washing water in the washing water inlet compartment 111 is drawn into the shaft direction. Bubbles are generated by mixing air with washing water by the difference in pressure in the bubble generating compartment 130 due to the pressure drop caused by the flowing of washing water. The bubbles are introduced into the tub 20 through the circulation port 134 and the circulation pipe 80 by the circulation impeller 132.
The pump filter 140 is mounted at the front surface of the washing water inlet compartment 111 to remove foreign substance on the washing water that is introduced into the tub 20.
The pump filter 140 is provided in the form of a cylinder having a hollowness, and includes a head part 141 and a body part 145. If the pump filter 140 is mounted on the pump case 110, the body part 145 of the pump filter 140 is accommodated at an inside the washing water inlet compartment 111 of the pump case 110.
The head part 141 is provided at a lateral side thereof with a second screw thread 143 that is screwed to the pump case 110. The head part 141 is provided at a front side thereof with a grip 142 that is grippable by a user to rotate the head part 141.
The washing water inlet compartment 111 is provided at a front side thereof with an entry 116 into which the pump filter 140 is inserted. A rim of the entry 116 is provided with a first screw thread 117 having a shape corresponding to the second screw thread 143 of the pump filter 140.
The head part 141 of the pump filter 140 is exposed to the front surface of the cabinet 10 by the through-hole 13 that passes through the lower side frame 10 b and the front side frame 10 a. A cover (not shown) to cover the through-hole 13 is coupled to the front side frame 10 a.
The user opens the cover (not shown) to expose the head part 141, and holds the grip 142 to rotate the head part 141 , thereby separating the pump filter 140 from the drain pump 100 a so as to replace or clean the pump filter 140.
The pump case 110 is coupled to a lower side frame 10 b through a mount part 150 that is formed at a lower portion of the pump case 110. As the mount part 150 is inserted into a coupling groove 14 which is formed at a portion of the lower side frame 10 b corresponding to the mount part 150, the pump case 110 is coupled to the lower side frame 10 b.
Fastening holes 155 and 156 are formed at a lower portion of an outer side of the bubble generating compartment 130 and the drain pump compartment 120 of the pump case 110 such that the pump case 110 is coupled to the protruding portion of the lower side frame 10 b. If a fastening member (not shown) is coupled to the fastening holes 155 and 156 through the protruding portion of the lower side frame 10 b, the protruding portion of the lower surface frame 10 b is coupled to the pump case 110.
Water remaining in the pump case 110 is discharged through a residual water outlet port 180 that is formed at a lower portion of the pump case 110. One end of a residual water hose (not shown) is connected to the residual water outlet port 180, and the other end of the residual water hose is exposed to the front surface of the cabinet 10 through the through-hole 13. Accordingly, a user removes the water remaining in the pump case 110 by use of the residual water hose (not shown) exposed to the front surface of the cabinet 10.
An inlet port 114 is provided on the washing water inlet compartment 111 while protruding to the rear side of the washing water inlet compartment 111. The washing water inlet compartment 111 communicates with the inlet port 114. A connection part connecting the washing water inlet compartment 111 to the inlet port 114 has an inlet hole 115 that is configured to connect the washing water inlet compartment 111 to the inlet port 114.
An inlet hose 70 is connected to the inlet port 114 such that the washing water in the tub 20 is introduced to the washing water inlet compartment 111 by passing through the inlet hose 70 and the inlet port 114 via the inlet hole 115.
An impeller 122 to forcedly draw the washing water in the washing water inlet compartment 111 and to discharge the drawn washing water, is installed in the drain pump compartment 120 of the pump case 110. The pumping motor 121 is connected to the impeller 122. The impeller 122, which is rotated by the pumping motor 121, draws in the washing water of the washing water inlet compartment 111 in the shaft direction, and discharges the washing water in the radial direction.
A drain hose 60 a is connected to the drain pump compartment 120 and configured to guide and drain the washing water pumped by the impeller 122 to the outside the cabinet 10.
A first suction port 123 is formed between the drain pump compartment 120 and the washing water inlet compartment 111, and serves as a passage, into which the washing water in the washing water inlet compartment 111 is drawn.
A second suction port 133 is formed between the bubble generating compartment 130 and the washing water inlet compartment 111, and serves as a passage, into which the washing water in the washing water inlet compartment 111 is drawn.
An outlet port 124 to discharge the washing water pumped by the impeller 122 is formed on the drain pump compartment 120 while extending to the rear side of the drain pump compartment 120.
The drain hose 60 a is connected to the outlet port 124.
The outlet port 124 and the drain hose 60 a form a drain line configured to guide the washing water from the drain pump compartment 120 to an outside.
In order to remove the air, which is generated by collision between the impeller 122 and the washing water, and the air, which is introduced when the washing water is introduced into the washing water inlet compartment 111, from the pump case 110, an air outlet port 160 is formed on the drain pump compartment 120 while protruding upward.
The washing water introduced into the washing water inlet compartment 11 naturally moves. However, the washing water, after passing through the washing water inlet compartment 111 and the drain pump compartment 120, is drained through the outlet port 124 and the drain hose 60 a while being forcedly discharged by the impeller 122 at a high speed. Accordingly, the amount of washing water being discharged is larger than that of washing water being introduced.
Due to the difference in amount between the washing water being introduced and the washing water being discharged, the upper portion of the drain pump compartment 120 is filled with a larger amount of air than the washing water inlet compartment 111 is.
Further, the velocity of the washing water is increased by the impeller rotating at a high speed, and the pressure of the drain pump compartment 120 is decreased. If the pressure falls below the saturated vapor pressure of the washing water, cavitation phenomenon that generates air bubbles dissolved in the washing water occurs. The air generated in the drain pump compartment 120 fills the drain pump compartment 120.
The air filled in the upper portion of the drain pump compartment 120 causes an abnormal oscillation and noise, and degrades the function of the drain pump 100 a. Accordingly, there is a need for removing the air. By forming the air outlet port 160 at the upper portion of the drain pump compartment 120 filled with the air, the discharging of air is effectively achieved.
One end of the drain hose 60 a, as described above, is guided to an outside the cabinet 10 by the hose guide 90. The other end of the drain hose 60 a is provided with a connection part 62 a configured to connect the other end of the drain hose 60 a to the outlet port 124.
An air inlet port 61 a is formed while protruding at the drain hose 60 a, and the air outlet port 160 is connected to the air inlet port 61 a through an air passage 170 a. One end of the air passage 170 a is connected to the air outlet port 160, and the other end of the air passage 170 a is connected to the air inlet port 160.
The air inlet port 61 a according to an embodiment of the present disclosure has been described as being formed on the drain hose 60 a. However, the aspect of the present disclosure is not limited thereto, and the air inlet port 61 a may be formed on the connection part 62 a or the air outlet port 160. Further, one end of the air passage 170 a may be connected directly the outside to discharge air from the air outlet port 160. The air passage 170 a may be connected to the outside and the air inlet port 61 a to improve the discharge of the air from the air outlet port 160.
Hereinafter, the flow of the washing water and the air will be described.
As the impeller 122 rotates, the washing water moves from the washing water inlet compartment 111 to the drain pump compartment 120 via the first suction port 123. Thereafter, the washing water, by passing through an outlet hole 125 of the drain pump compartment 120, is discharged to an outside the cabinet 10 via the outlet port 124 and the drain hose 60 a.
The washing water in the drain pump compartment 120 is moved to the outlet port 124 and the drain hose 60 a by the impeller 122 at a high speed. In this case, the washing water flowing from the washing water inlet compartment 111 to the drain pump compartment 120, that is, the washing water passing through the first suction port 123, flows at a velocity higher than that of the washing water passing through the outlet port 124 and the drain hose 60 a.
Since the pump case 110 is not substantially different in height from the drain hose 60 a, when the heights of the pump case 110 and the drain hose 60 a are assumed to be same, the pressure of the drain hose 60 a is lower than the pressure of the first suction port 123 according to Bernoulli's principle.
u ²/2+g·h+ρ/=constant (Bernoulli's principle)
That is, the pressure of the air outlet port 160 is higher than the pressure of the air inlet port 61 a.
As described above, the difference in amount between the washing water being discharged and the washing water being introduced as well as the cavitation phenomenon cause the upper portion of the drain pump compartment 120 to be filled with air. The difference in pressure allows the air to flow from the air outlet port 160 to the air inlet port 61 a through the air passage 170 a.
According to the above structure as such, the air in the drain pump 100 a is naturally discharged to an outside the cabinet 10 through the drain hose 60 a.
Therefore, the air is removed from the drain pump 100 a, in particular, from the drain pump compartment 120, so that the vibration and noise are removed, and the efficiency of the drain pump is enhanced.
FIG. 7 is a perspective view illustrating a drain pump in accordance with another embodiment of the present disclosure.
The description of the same reference numerals will be assigned to elements identical to the elements according to the previous embodiment, and description thereof will be omitted.
Referring to FIG. 7, a drain pump 100 b includes a washing water inlet compartment (111 in FIG. 6), a pump case 110 provided with a drain pump compartment (120 in FIG. 6) and a bubble generating compartment (130 in FIG. 6), and a pump filter 140 inserted into the washing water inlet compartment 111.
The bubble generating motor 131 is connected to one end of the pump case 110 including the bubble generating compartment 130. The circulation port 134 is formed at the upper portion of the bubble generating compartment 130. The circulation pipe 80 is connected to the circulation port 134.
The pump filter 140 is inserted into the front surface of the drain pump 100 b.
The washing inlet compartment (111 in FIG. 6) is formed in the center at an inside of the drain pump 100 b. The inlet port 114 is provided on the washing water inlet compartment 111 while protruding to the rear side of the washing water inlet compartment 111. An inlet hose 70 is connected to the inlet port 114 such that the washing water in the tub 20 is introduced to the washing water inlet compartment 111. One end of the inlet hose 70 is connected to the inlet port 114 and the other end of the inlet hose 70 is connected to the tub (20 in FIG. 1).
The washing water in the tub 20 is introduced into the washing water inlet compartment 111 in the drain pump 100 b through the inlet hose 70.
The drain pump compartment (120 in FIG. 6) is formed at the opposite end of the pump case 110 including the bubble generating motor 131. The pumping motor 121 provided with the impeller (122 in FIG. 3) is mounted on the drain pump compartment 120.
As described above, the upper portion of the inner side of the drain pump compartment 120 is filled with air. Accordingly, the air outlet port 160 is provided while protruding at the upper portion of the outer side of the drain pump compartment 120 to discharge air.
A drain hose 60 b is provided with a connection part 62 b configured to connect to the outlet port 124 that protrudes to the rear side of the pump case 110.
An air passage 170 b branches from the drain hose 60 b while being integrally formed with the drain hose 60 b. The air passage 170 b is connected to the air outlet port 160.
As described above, since the velocity of the washing water at the drain hose 60 b is higher than that of the washing water in the drain pump compartment 120, the pressure in the pump case 110 is higher than the pressure in the drain hose 60 b according to Bernoulli's principle.
Accordingly, the air in the upper portion of the drain pump compartment 120 moves along from the air outlet port 160 to the drain hose 60 b. The air reached to drain hose 60 b is discharged to an outside of the cabinet 10 together with the washing water.
As the air in the pump case 110 is reduced, the vibration and noise occurring in the drain pump is reduced, and the efficiency of the drain pump is enhanced.
Although a few embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.

Claims

What is claimed is:

1. A drain pump comprising:

a washing water inlet compartment;

a drain pump compartment configured to pump washing water contained in the washing water inlet compartment to an outside;

a suction port provided between the washing water inlet compartment and the drain pump compartment to move the washing water from the washing water inlet compartment to the drain pump compartment;

a drain line to connect the drain pump compartment to the outside, to discharge the washing water; and

an air outlet port provided on the drain pump compartment to discharge air contained in the drain pump compartment,

wherein the air outlet port is connected to the drain line.

2. The drain pump of claim 1, wherein air naturally flows from the air outlet port to the drain line due to the difference in pressure between the drain pump compartment and the drain line.

3. The drain pump of claim 1, wherein the air outlet port protrudes at an upper portion of the drain pump compartment.

4. The drain pump of claim 1, further comprising an air inlet port provided on the drain line, wherein the air outlet port is connected to the air inlet port.

5. The drain pump of claim 4, further comprising an air passage to connect the air outlet port to the air inlet port.

6. The drain pump of claim 5, wherein the air passage comprises a rubber hose.

7. The drain pump of claim 4, wherein the air inlet port is integrally formed with the drain line.

8. The drain pump of claim 4, wherein the air inlet port is separately formed with the drain line and coupled to the drain line.

9. The drain pump of claim 1, wherein the drain line comprises a drain passage connected to the drain pump compartment, and an air passage connected to the air outlet port.

10. The drain pump of claim 9, wherein the air passage is branched from the drain passage.

11. The drain pump of claim 9, wherein the air passage is integrally formed with the drain passage.

12. The drain pump of claim 9, wherein the air passage has a diameter smaller than a diameter of the drain passage.

13. The drain pump of claim 1, wherein the drain line comprises an outlet port protruded at the pump case, and a drain hose including one end connected to the outlet port and the other end extended to an outside.

14. A drain pump comprising:

a pump case configured to accommodate washing water;

a pumping motor provided at one end of the pump case to pump the washing water to an outside;

a drain hose connected to the pump case while being adjacent to the pumping motor such that the washing water pumped by the pumping motor flows to an outside;

an air outlet port formed at a side of an upper portion of the pump case to discharge air, the side adjacent to the pumping motor;

an air inlet port protruded at the drain hose; and

an air passage to connect the air outlet port to the air inlet port.

15. The drain pump of claim 14, wherein air naturally flows from the air outlet port to the air inlet port due to the difference in pressure between the drain hose and the pump case, the difference in pressure caused by the difference in velocity between the washing water flowing in the drain hose and the washing water flowing in the pump case.

16. A drain pump comprising:

a pump case configured to accommodate washing water;

a pumping motor provided at a portion of the pump case to generate a driving force to allow the washing water to be forcedly discharged to an outside;

a drain hose connected to the portion of the pump case, at which the pumping motor is provided, to guide the washing water to an outside;

an air outlet port protruded at an upper portion of the pump case, at which the pumping motor is provided, to discharge air; and

an air passage including one end connected to the air outlet port and the other end connected to the drain hose.

17. The drain pump of claim 16, wherein the air passage is integrally formed with the drain hose.

18. A washing machine provided with a tub, a drain pump to pump washing water in the tub, and a drain hose configured to allow the washing water pumped by the drain pump to flow therethrough,

wherein the drain pump comprises:

a washing water inlet compartment into which the washing water is introduced from the tub;

a drain pump compartment provided with a suction port to draw the washing water in the washing water inlet compartment, and an outlet port connected to a drain hose which is configured to drain the washing water;

an air outlet port protruded at an upper portion of the drain pump compartment; and

an air passage to connect the air outlet port to the drain hose.

19. The washing machine of claim 18, wherein the drain hose comprises an air inlet port protruded at the drain hose,

wherein the air passage includes one end connected to the air outlet port and the other end connected to the air inlet port.

20. The washing machine of claim 18, wherein the other end of the air passage is integrally formed with the drain hose.

21. A washing machine comprising:

a cabinet;

a tub disposed at an inside the cabinet to accommodate washing water;

a drain pump disposed at a lower portion of the tub to drain the washing water contained in the tub;

a drain line connected to the drain pump to guide the washing water, which is pumped by the drain pump, to an outside the cabinet; and

an air passage to connect the drain pump to the drain line to discharge air contained in the drain pump.

22. The washing machine of claim 21, wherein the drain pump comprises an air outlet port protruded upward, at the drain pump, and the drain line comprises an air inlet port protruded upward, at the drain line,

wherein one end of the air passage is connected to the air outlet port and the other end of the air passage is connected to the air inlet port.

23. The washing machine of claim 21, wherein the drain pump comprises an air outlet port protruded upward, at the drain pump,

wherein one end of the air passage is connected to the air outlet port and the other end of the air passage is integrally formed with the drain line.