US20180305853A1

US20180305853A1 - Drainage structure of water-saving washing machine, and washing machine

Info

Publication number: US20180305853A1
Application number: US15/770,849
Authority: US
Inventors: Sheng Xu; Zhiqiang Zhao
Original assignee: Qingdao Haier Washing Machine Co Ltd
Current assignee: Qingdao Haier Washing Machine Co Ltd
Priority date: 2015-10-29
Filing date: 2016-10-27
Publication date: 2018-10-25
Also published as: EP3369856A4; CN106637839A; CN106637839B; EP3369856B1; KR20180074710A; EP3369856A1; WO2017071611A1; JP2018532504A

Abstract

A drainage structure of a washing machine has a central hole at the inner tub bottom of the washing machine, and an annular groove is arranged around the central hole; the inner part and the outer part of the inner tub communicate with a water flow passage on the annular groove, and the annular groove has a sealing member capable of reciprocating motion for controlling the on-off state of the water flow passage. The upper part of the sealing member has an elastic member for controlling the downward movement of the sealing member to contact the inner tub bottom and/or the bottom surface of the annular groove, and the lower part of the sealing member has a driving member for controlling the upward movement of the sealing member to separate from the inner tub bottom and/or the bottom surface of the annular groove.

Description

TECHNICAL FIELD

The present disclosure relates to the field of washing machines, in particular to a drainage structure of a water-saving washing machine and a washing machine.

BACKGROUND

It is well known that the pulsator washing machine has the advantages of short washing time and high washing efficiency, and it is convenient to add clothes in the middle of a washing. However, the water consumption of the washing machine is relatively high. Generally, under the standard procedure, the water consumption of an 8 kg pulsator washing machine is about 180 L for washing one times and rinsing two times. The water consumption is high, and it is not easy to clean the space between the inner and outer tubs, which results in easily breeding bacteria.
In order to solve the above problems, a structure of a holeless inner tub has been developed. During washing, there is no water between the inner tub and the outer tub. However, water discharging of the inner tub becomes a problem. One design is to apply a cycle of drain holes along the upper part of the inner tub and all the water inside the inner tub is discharged from the drain hole at the upper part of the inner tub by the centrifugal force of rotation. On one hand, in this design, the speed of drainage is slow; on the other hand, the dirt in the water, such as sediment, is difficult to discharge. Another design is to arrange a water containing chamber right below the inner tub, and the water containing chamber communicates with the inner tub. The upper edge of the water containing chamber is sealed with the lower edge of the inner tub, and a drainage hole is arranged at the lower part of the water containing chamber; the control of the drainage is achieved by controlling the opening and closing of the drainage hole. However, during the water discharging, the inner tub rotates at a high speed while the water containing chamber staying still. So the sealing between the two parts is not easy to achieve, and even if it is easily realized, the two parts relatively rotates in a high speed for a long time are also prone to wear and tear. One other design is to arrange the drainage holes at the inner tub bottom. During washing, the drainage holes at the inner tub bottom are blocked by a drain valve after the inner tub being fixed. During drainage, the drainage holes are open by the control of the drain valve. This kind of structure also needs to set a position fixed structure of the inner tub. High accuracy of positioning is demanded, and the structure is complicated. Meanwhile, the inner tub cannot rotate during washing, and it is unable to achieve dual power washing.
The present disclosure is purposed in view of the above.

SUMMARY

The purpose of the present disclosure is to overcome the shortcomings of the prior art and to provide a water drainage structure for a water-saving washing machine and a washing machine, the structure is simple with a high reliability.
In order to achieve the object, the present disclosure adopts the following technical solutions: a drainage structure of a water-saving washing machine, wherein a central hole is arranged at an inner tub bottom of the washing machine, and an annular groove is arranged around the central hole. A water flow passage communicating an inner part and an outer part of the inner tub is provided on the annular groove, and the annular groove is provided with a sealing member capable of reciprocating to control an on-off state of the water flow passage.
An upper part of the sealing member is provided with an elastic member for controlling a downward movement of the sealing member to contact with the inner tub bottom and/or a bottom surface of the annular groove. A lower part of the sealing member is provided with a driving member for controlling an upward movement of the sealing member to separate from the inner tub bottom and/or the bottom surface of the annular groove.
A diameter of an upper part is larger than a diameter of a lower part of an outer periphery of the sealing member, and a first step is formed at a place where a diameter of the outer periphery is dramatically changed, the lower part of the sealing member is located in the annular groove. At a closed state, the first step is in contact with the inner tub bottom, and an end face of a bottom of the sealing member is in contact the bottom surface of the annular groove. At an open state, the first step is disengaged from the inner tub bottom, and the end face of the bottom of the sealing member is disengaged from the bottom surface of the annular groove.
One side surface, near a center of the inner tub, of two side surfaces of the annular groove is a first side surface, and one side surface away from the center of the inner tub is a second side surface. A distance between an outer periphery of a lower part of the sealing member and the second side surface, and/or between an inner periphery of the lower part of the sealing member and the first side surface forms an annular gap.
One side surface, near the center of the inner tub, in the two side surfaces of the annular groove is the first side surface, and one side surface away from the center of the inner tub is the second side surface. The second side surface is inclined outward from bottom to top, and the outer periphery of the lower part of the sealing member is inclined outward from bottom to top. An angle between the second side surface and a horizontal surface is larger than an angle between the outer periphery of the lower part of the sealing member and the horizontal plane.
The water flow passage is at least one opening which is provided on a bottom wall of the annular groove.
Preferably, the water flow passage further comprises several water outlets provided on the bottom wall of the annular groove and/or a side wall, away from the central hole, of the annular groove.
At least a part of the driving member extends into the opening to drive the sealing member, and the driving member comprises a lever, a supporting point of the lever and a driving part of the lever. The supporting point of the lever is arranged at a bottom of the outer tub, and a middle part of the lever hinge joints with the supporting point; one end of the lever extends into the opening and is located below the sealing member, and the other end of the lever is connected with the driving part.
Preferably, the driving part comprises a traction motor, a traction rope and a positioning block of the traction rope; the traction motor is arranged at a lower part of an outer side wall of the outer tub, and the traction rope is connected to the traction motor and the lever; the positioning block is a hook-shaped raised part on an inner wall of the outer tub.
The upper part or an inner part of the sealing member is provided with a first mounting part of the elastic member, and a second mounting part of the elastic member is arranged on an upper side wall, near the center of the inner tub, of the annular groove.
Preferably, a second step is provided in the sealing member, and the second step is the first mounting part of the elastic member.
Preferably, the side wall, closing to the center of the inner tub, of the annular groove encloses the central hole for the inner tub, and an inner tub shaft is arranged in the central hole; the inner tub shaft and the side wall, closing to the center of the inner tub, of the annular groove are connected by a fasten member; a portion of the fasten member beyond an periphery of the side wall, near the center of the inner tub, of the annular groove forms the second mounting part of the elastic member.
A length of the sealing member is greater than or equal to a length of the side wall, closing to the center of the inner tub, of the annular groove, and a diameter at the second step is slightly larger than an outer diameter of the second mounting part. Or a third step is provided inside the sealing member; a diameter at the third step is greater than the diameter at the second step; the diameter at the third step is slightly greater than an outer diameter of the second mounting part.
A washing machine with the above described drainage structure.
By adopting the technical solution of the present disclosure, the following beneficial effects are brought: with the drainage structure of the present disclosure, it is only need to control the reciprocation motion of the sealing member to achieve the control of the drainage, so the control is simple. In addition, the sealing member is disposed in the inner annular groove at the inner tub bottom, and it is relatively fixed with the inner tub at the rotational direction. In this way, the wear of the sealing member is small, and the reliability is high; the accuracy demand of the positioning of the inner tub is lower, and the positioning structure and the control program of the inner tub is simplified. All the seals are the end face contacting seals, which are reliable.
The specific embodiments of the present disclosure are described in further detail below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: The structure diagram of the water-saving washing machine in the present disclosure;

FIG. 2: The structure diagram of the water-saving washing machine (without outer shell) in the present disclosure;

FIG. 3: The structure diagram at the closed state in the embodiment 1 of the present disclosure;

FIG. 4: The structure diagram at the opening state in the embodiment 1 of the present disclosure;

FIG. 5: The structure diagram at the closed state in the embodiment 3 of the present disclosure;

FIG. 6: The structure diagram at the opening state in the embodiment 3 of the present disclosure;

FIG. 7: The structure diagram at the closed state in the embodiment 4 of the present disclosure;

FIG. 8: The structure diagram at the opening state in the embodiment 4 of the present disclosure.

Wherein: 1—central hole, 2—annular groove, 3—sealing member, 4—elastic member, 5—driving member, 6—first step, 7—inner tub bottom, 8—first side surface, 9—second side surface, 10—first annular gap, 11—second annular gap, 12—hole, 13—water outlet, 14—lever, 15—supporting point, 16—driving part, 17—traction motor, 18—traction rope, 19—positioning block, 20—fasten member, 21—second step, 23—third step, 24—outer shell, 25—cover seat, 26—top lid, 27—bottom feet, 28—outer tub, 29—inner tub, 30—drain outlet, 31—drain hose, 32—drainage hole, 33—inner tub shaft.

DETAILED DESCRIPTION OF THE EMBODIMENTS

As shown in FIGS. 1 and 2, in the drainage structure of the water-saving washing machine of the present disclosure, a central hole 1 is arranged at the inner tub bottom of the washing machine, and an annular groove 2 is arranged around the central hole 1; a water flow passage for communicating the inner part and the outer part of the inner tub is provided on the annular groove 2, and the annular groove 2 is provided with the sealing member 3 capable of reciprocating motion for controlling the on-off state of the water flow passage. During the washing, the sealing member 3 moves to a position to cut off the water flow passage, the washing water only exists in the inner tub. During water discharging, the sealing member 3 moves to another position, and the water flow passage opens, then the washing water is discharged through the water flow passage and the outer tub. As the control of the drainage is only needs to control the reciprocation of the sealing member, the control process is simple. In addition, the sealing member 3 is disposed in the inner annular groove 2 of the inner tub bottom 7, and it is relatively fixed with the inner tub at the rotational direction. In this way, the wear of the sealing member is small, and the reliability is high.
The upper part of the sealing member 3 is provided with the elastic member 4 for controlling the downward movement of the sealing member 3 to fit with the inner tub bottom and/or the bottom surface of the annular groove. The elastic member 4 is at the compressed state, at which the sealing member 3 is compressed to seal the water flow passage by the resilience of the elastic member 4. In addition, the lower part of the sealing member 3 is provided with a driving member 5 for controlling the upward movement of the sealing member 3 to separate from the inner tub bottom and/or the bottom surface of the annular groove. The driving member 5 drives the sealing member 3 to move upward under the traction of the traction motor 17, and the upward driving force is larger than the resilience of the elastic member 4, as a result, the water in the inner tub is drained. At the natural state, the resilience force of the elastic member 4 compresses the sealing member 3 to seal the water flow passage. When drainage is needed, the driving member drives the sealing member to move upward to separate from the inner tub bottom and/or the annular groove, then the water flow passage opens and drainage is achieved.
The diameter of the outer circumference of the upper part of the sealing member 3 is larger than the diameter of that of the lower part, and a first step 6 is formed at the place where the diameter of the outer circumference of the sealing member is dramatically changed. At the closed state, the first step 6 contacts with the inner tub bottom 7 to form an annular end face contact seal and the end face of the bottom of the sealing member 3 contacts with the bottom surface of the annular groove to form the annular end face contact seal. At the open state, the first step 6 is disengaged from the inner tub bottom 7, and the end face of the sealing member bottom is disengaged from the bottom surface of the annular groove. At the seal state, the sealing member 3 and the inner tub bottom 7, the bottom end surface of the sealing member 3 and the bottom surface of the annular groove, both are annular end surface contact seal, and the sealing is reliable. The sealing member is an annular sleeve structure, and the upper part of the outer periphery of the sealing member is provided with a ring of bosses protruding outward. In the closed state, the lower surface of the boss contacts with the inner tub bottom to form a seal. The lower part of the sealing member is embedded in the annular groove at the inner tub bottom and is in a closed state, and the bottom of the seal contacts with the bottom surface of the annular groove to form an annular end surface contact seal to further ensure the sealing effect.
The upper part or the inner part of the sealing member 3 is provided with a first mounting part of the elastic member 4, and a second mounting part of the elastic member 4 is arranged on the upper side wall near the center of the inner tub of the annular groove 2. One end of the elastic member 4 is fixed to the second mounting part, and the second mounting part is a fixing structure for preventing the end of the elastic member 4 from moving; and the other end of the elastic member 4 is fixed to the first mounting part, and it moves along with the movement of the sealing member.
Preferably, the second step 21 is provided inside the sealing member 3, and the second step 21 is the first mounting part of the elastic member 3. The elastic member 4 is located inside the sealing member 3, and this arrangement saves the installation space and leaves more installation space for the pulsator without reducing the capacity of the inner tub. The second mounting part is a stop plate fixed to the side wall, closing to the center of the inner tub, of the annular groove. Preferably, the side wall, closing to the center of the inner tub, of the annular groove encloses to form a central hole 1 of the inner tub. The central hole is provided with an inner tub shaft and, the inner tub shaft and the side wall, closing to the center of the inner tub, of the annular groove are connected by a fasten member 20. A portion of the fasten member 20 beyond the periphery of the side wall, closing the center of the inner tub, of the annular groove forms the second mounting part of the elastic member. The fasten member 20 serves both as a connection of the inner tub shaft with the inner tub and as playing the role of mounting the elastic member. It makes all the used parts get full use and reduces the number of the parts. The side wall, closing to the inner tub centre, of the annular groove 2 is higher than the inner tub bottom to provide space for the reciprocating motion of the sealing member 3.
The bottom wall of the annular groove is provided with at least one opening 12. The driving member drives the sealing member 3 through the opening 12, and the water flow passage is the opening 12. Further, in order to increase the drainage speed, a plurality of water outlets 13 are evenly distributed on the bottom wall or the side wall far away from the center hole of the annular groove. The opening is a notch at the intersection of the bottom wall of the annular groove and the sidewall away from the center of the inner tub of the annular groove. The notch of the bottom wall of the annular groove ensures the lever can extend below the sealing member and the notch of the sidewall away from the center of the inner tub of the annular groove ensures that the lever can drive the sealing member 3 to move upward by a certain distance.
When the water need to be discharged, the inner tub is positioned to the opening 12 aligning with the lever 14 to control the drainage. Since the opening has a certain width in the circumferential direction which is much larger than the diameter of the lever, the positioning precision of the inner tub is less demanding. As long as the lever is in the opening 12, the control of the drainage can be achieved, so the structure and procedure of the positioning control is simplified.
The driving member comprises the lever 14, the supporting point 15 of the lever 14 and the driving part 16 of the lever. The supporting point 15 of the lever 14 is arranged at the bottom of the outer tub, and the middle part of the lever 14 hinge joints with the supporting point 15. One end of the lever 14 extends though the opening 12 and located below the sealing member 3, and the other end of the lever 14 is connected with the driving part 16. Preferably, the driving part 16 comprises the traction motor 17, the traction rope 18 and the positioning block 19 for the traction rope 18. The traction motor 17 is arranged on the lower part of the outer side wall of the outer tub, thus it avoids occupying the space at the inner tub bottom and leaves more installation space for the inner tub. The traction rope 18 is connected to the traction motor 17 and the lever 14. The positioning block 19 is a hook-shaped raised part on the inner wall of the outer tub. The hook-shaped raised part locates the traction rope along the inner wall of the outer tub to avoid interference with the rotation of the inner tub.
Preferably, the bottom wall of the annular groove is uniformly provided with two or more openings 12, and the ends of the levers 14 are provided with branches, each of which extends into the openings 12 to drive the sealing member. One traction motor drives one lever, and multiple branches of an end of one lever evenly drive the multiple parts of the sealing member.
The side surface near the center of the inner tub in the two side surfaces of the annular groove 2 is the first side surface 8, and the side surface away from the center of the inner tub is the second side surface 9. The part of the sealing member 3 that protruding into the annular groove 2 is at a distance away from the second side surface 9 or the first side surface 8, forming an annular gap. The water flows into the annular groove 2 through the annular gap and is discharged through the water flow passage.

Embodiment 1

As shown in FIG. 3 and FIG. 4, in this embodiment, the second side surface 9 have a certain distance away from the outer periphery of the lower part of the sealing member 3, and a first annular gap 10 is formed between the second side surface 9 and the outer periphery of the lower part of the sealing member. The first side surface 8 is sealed against the inner periphery of the lower part of the sealing member. The sealing member moves upward and separates from the inner tub bottom and/or the bottom surface of the annular groove, then the water flows into the annular groove 2 through the first annular gap 10 and is discharged through the water flow passage.

Embodiment 2

In the present embodiment, the first side surface 8 has a certain distance away from the inner periphery of the lower part of the sealing member. A second annular gap 11 is formed between the first side surface 8 and the inner periphery of the lower part of the sealing member. The second side surface 9 is in contact with the outer periphery of the lower part of the sealing member and seals. The sealing member moves upward and separates from the inner tub bottom and/or the bottom surface of the annular groove, then the water flows into the annular groove through the second annular gap 11 and is discharged through the water flow passage.

Embodiment 3

As shown in FIG. 5 and FIG. 6, in this embodiment, the second side surface 9 is spaced from the outer periphery of the lower part of the sealing member, forming a first annular gap 10 between the second side surface 9 and the outer periphery of the lower part of the sealing member. The first side surface 8 is spaced from the inner periphery of the lower part of the sealing member, and a second annular gap 11 is formed between the first side surface 8 and the inner periphery of the lower part of the sealing member. After the sealing member moves upward and separates from the inner tub bottom and/or the bottom surface of the annular groove, the water flows into the annular groove through the first annular gap 10 and the second annular gap 11 and then is discharged through the water flow passage. The arrangement of two annular gaps accelerates the drainage speed. As gaps are provided between the sealing member and both sides of the annular groove, the sealing member needs to be positioned circumferentially. Thus, the length of the sealing member is greater than or equal to the length of the side wall, closing to the center of the inner tub, of the annular groove, and the diameter at the second step 21 is slightly larger than the outer diameter of the second mounting part, or the third step 23 is provided inside the sealing member. The diameter at the third step 23 is greater than the diameter at the second step 21. The diameter at the third step 23 is slightly greater than the outer diameter of the second mounting part. The sealing member is circumferentially positioned by the contact between the second mounting part and the inner part of the sealing member.

Embodiment 4

As shown in FIG. 7 and FIG. 8, in the present embodiment, the second side surface 9 is from the bottom to the top, and the outer periphery of the lower part of the sealing member 3 is inclined outward from the bottom to the top. The angle a between the second side surface and the horizontal plane is larger than the angle b between the outer periphery of the lower part of the sealing member and the horizontal plane. The first side surface 8 is in contact with the inner periphery of the lower part of the sealing member and seals. That is, the lower part of the outer periphery of the sealing member 3 is provided with a taper, and the second side surface of the annular groove is provided with a taper. In addition, the taper of the second side surface is greater than the taper of the lower part of the outer periphery of the sealing member. The provided taper has a good effect on direction guide for the downward movement of the sealing member.

Embodiment 5

In the present embodiment, a washing machine with the above drainage structure comprises an outer shell 24, a cover seat 25, a top lid 26, bottom feet 27, an outer tub 28, and an inner tub 29. The outer tub 28 is only used for temporarily storing a part of the washing water when the washing machine is draining, and a lower part of the outer tub is provided with a drain outlet 30 for connecting the drain hose 31 to discharge the washing water or the rinsing water out of the washing machine. A hole is provided at the center of the bottom of the outer tub 28 for placing the bearings and the sealing device, and the inner tub shaft 33 passes through the hole. The two ends communicate with the drive motor and the inner tub respectively. Hence, the inner tub is driven to rotate by the motor for washing clothes or drying clothes with high-speed spinning. A ring of drainage holes 32 is arranged on the upper part of the inner tub 29. When excessive amount of water flows into the inner tub, the water flows through the drainage hole 32 to the outer tub, and then flows out from the washing machine. When the wet laundry is dried at a high speed spin, the water flows upward and can pass through the drainage hole 32 to the outer tub, and then flows out from the washing machine.
The lower part and the middle of the inner tub 29 are ensured without water leakage hole. Under the resilience of the elastic member, the first step of the sealing member is in contact with the inner tub bottom and the bottom of the sealing member is in contact with the bottom of the annular groove, then the inner tub bottom is sealed. And the washing starts, the water inlet valve opens and the tap water enters the inner tub. After water entering is completed, the inner tub rotates and washes clothes. When drainage is required, the traction motor pulls the traction rope, and then the traction rope pulls the levers, the lever drives the sealing member to move upward. The sealing member moves upward, and the first step of the sealing member is disengaged from the inner tub bottom and the bottom of the sealing member is disengaged from the bottom of the annular groove. The water flows through the annular gap into the annular groove, and then discharged through the water passage from the inner tub. After drainage, the traction motor is de-energized, and the sealing member is moved downward by the resilience of the elastic member. The first step of the sealing member is in contact with the inner tub bottom, and the bottom of the sealing member is in contact with the bottom of the annular groove, thus the inner tub bottom is sealed.
The above descriptions are merely preferred embodiments of the present disclosure, and it should be noted that various modifications and improvements can be made by those skilled in the art without departing from the principle of the present disclosure, and then it should also be regarded as inside the scope of the present disclosure.

Claims

1. A drainage structure of a water-saving washing machine, comprises a central hole arranged at an inner tub bottom of the washing machine, and an annular groove arranged around the central hole; wherein,

a water flow passage communicating an inner part and an outer part of the inner tub is provided on the annular groove, and the annular groove is provided with a sealing member capable of reciprocating to control an on-off state of the water flow passage.

2. The drainage structure of the water-saving washing machine according to claim 1, wherein an upper part of the sealing member is provided with an elastic member for controlling a downward movement of the sealing member to contact with the inner tub bottom and/or a bottom surface of the annular groove,

and a lower part of the sealing member is provided with a driving member for controlling an upward movement of the sealing member to separate from the inner tub bottom and/or the bottom surface of the annular groove.

3. The drainage structure of the water-saving washing machine according to claim 1, wherein a diameter of an upper part is larger than a diameter of a lower part of an outer periphery of the sealing member, and a first step is formed at a place where a diameter of the outer periphery is dramatically changed, the lower part of the sealing member is located in the annular groove;

at a closed state, the first step is in contact with the inner tub bottom, and an end face of a bottom of the sealing member is in contact the bottom surface of the annular groove;

at an open state, the first step is disengaged from the inner tub bottom, and the end face of the bottom of the sealing member is disengaged from the bottom surface of the annular groove.

4. The drainage structure of the water-saving washing machine according to claim 1, wherein one side surface, near a center of the inner tub, of two side surfaces of the annular groove is a first side surface,

and one side surface away from the center of the inner tub is a second side surface;

a distance between an outer periphery of a lower part of the sealing member and the second side surface, and/or between an inner periphery of the lower part of the sealing member and the first side surface forms an annular gap.

5. The drainage structure of the water-saving washing machine according to claim 1, wherein one side surface, near the center of the inner tub, in the two side surfaces of the annular groove is the first side surface, and one side surface away from the center of the inner tub is the second side surface;

the second side surface is inclined outward from bottom to top, and the outer periphery of the lower part of the sealing member is inclined outward from bottom to top;

an angle between the second side surface and a horizontal surface is larger than an angle between the outer periphery of the lower part of the sealing member and the horizontal plane.

6. The drainage structure of the water-saving washing machine according to claim 1, wherein the water flow passage is at least one opening which is provided on a bottom wall of the annular groove.

7. The drainage structure of the water-saving washing machine according to claim 6, wherein at least a part of the driving member extends into the opening to drive the sealing member,

and the driving member comprises a lever, a supporting point of the lever and a driving part of the lever;

the supporting point of the lever is arranged at an inner bottom of the outer tub, and a middle part of the lever hinges with the supporting point; one end of the lever extends into the opening and is located below the sealing member, and another end of the lever is connected with the driving part.

8. The drainage structure of the water-saving washing machine according to claim 1, wherein the upper part or an inner part of the sealing member is provided with a first mounting part of the elastic member, and a second mounting part of the elastic member is arranged on an upper side wall, near the center of the inner tub, of the annular groove.

9. The drainage structure of the water-saving washing machine according to claim 8, wherein a length of the sealing member is greater than or equal to a length of the side wall, closing to the center of the inner tub, of the annular groove,

and a diameter at the second step is slightly larger than an outer diameter of the second mounting part,

or a third step is provided inside the sealing member; a diameter at the third step is greater than the diameter at the second step; the diameter at the third step is slightly greater than an outer diameter of the second mounting part.

10. A washing machine with the drainage structure that described in claim 1.

11. The drainage structure of the water-saving washing machine according to claim 2, wherein a diameter of an upper part is larger than a diameter of a lower part of an outer periphery of the sealing member, and a first step is formed at a place where a diameter of the outer periphery is dramatically changed, the lower part of the sealing member is located in the annular groove;

12. The drainage structure of the water-saving washing machine according to claim 2, wherein one side surface, near a center of the inner tub, of two side surfaces of the annular groove is a first side surface,

13. The drainage structure of the water-saving washing machine according to claim 2, wherein one side surface, near the center of the inner tub, in the two side surfaces of the annular groove is the first side surface, and one side surface away from the center of the inner tub is the second side surface;

14. The drainage structure of the water-saving washing machine according to claim 6, wherein the water flow passage further comprises several water outlets provided on the bottom wall of the annular groove and/or a side wall, away from the central hole, of the annular groove.

15. The drainage structure of the water-saving washing machine according to claim 7, wherein the driving part comprises a traction motor, a traction rope and a positioning block of the traction rope; the traction motor is arranged at a lower part of an outer side wall of the outer tub, and the traction rope is connected to the traction motor and the lever; the positioning block is a hook-shaped raised part on an inner wall of the outer tub.

16. The drainage structure of the water-saving washing machine according to claim 8, wherein a second step is provided in the sealing member, and the second step is the first mounting part of the elastic member.

17. The drainage structure of the water-saving washing machine according to claim 8, wherein the side wall, closing to the center of the inner tub, of the annular groove encloses the central hole for the inner tub, and an inner tub shaft is arranged in the central hole; the inner tub shaft and the side wall, closing to the center of the inner tub, of the annular groove are connected by a fasten member; a portion of the fasten member beyond an periphery of the side wall, near the center of the inner tub, of the annular groove forms the second mounting part of the elastic member.

18. The drainage structure of the water-saving washing machine according to claim 2, wherein the upper part or an inner part of the sealing member is provided with a first mounting part of the elastic member, and a second mounting part of the elastic member is arranged on an upper side wall, near the center of the inner tub, of the annular groove.