CN1252338C

CN1252338C - Kneading type washing machine

Info

Publication number: CN1252338C
Application number: CN 200310106169
Authority: CN
Inventors: 胡冬喜
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-10-28
Filing date: 2003-10-28
Publication date: 2006-04-19
Anticipated expiration: 2023-10-28
Also published as: CN1540058A

Abstract

The present invention relates to a kneading type washing machine. An upper washing mechanism is formed by that an upper wave wheel, an upper transmission mechanism, an upper washing motor, an upper lifting motor, etc. which can lift vertically and are arranged in an upper cover are arranged in the upper cover additionally, and the mutual twisting of the washing mode is realized so as to enhance cleaning degrees greatly. A washing cylinder adopts a structure of which the bottom is sealed, so that leakage does not exist. By using the kneading type washing machine of the present invention, the use levels of washing agents, water and electricity, and washing time are saved greatly, and simultaneously, the generation level of washing sewage is reduced greatly.

Description

Rubbing type washing machine

The technical field is as follows:

the invention relates to a household washing machine, in particular to a rubbing type washing machine with a rubbing type washing mode.

(II) background technology:

washing machines are commonly used household appliances. At present, people have higher and higher requirements on washing machines, and the washing machines are required to have high cleaning degree, high automation degree, electricity saving, water saving and detergent saving. According to the structural principle, the household washing machines in the prior art can be divided into three categories, namely impeller type (most of the washing machines are produced in China), drum type and stirring type. Wherein, the impeller type is to form strong vortex by the continuous rotation or regular and reverse rotation of the impeller to wash the washing clothes immersed in the washing liquid, and the impeller type can be divided into vortex type, jet flow type and double jet flow type; the drum type washing machine has its inner tub rotated regularly, and the ribs on the inner wall of the tub make the clothing inside the tub in certain height and fall into the washing liquid to complete washing. The agitator type washing machine performs washing by agitating washing liquid and laundry by means of an agitator vertically installed at the center of a washing tub. Among the three types of washing machines, the drum type washing machine has a complex structure, large manufacturing difficulty and high manufacturing cost; the stirring type washing machine has large and heavy body and high cost, and the sleeve barrel (cylinder) type full-automatic impeller washing machine has certain comprehensive advantages due to moderate price, high automation degree and good cleaning degree, and has become the mainstream. The three types of washing machines have the common defect that the cleaning degree is not satisfactory. In addition, various household washing machines in the prior art all have a common disadvantage: the quantity of the washing liquid is large, so that the water consumption and the electricity consumption in the washing process of various household washing machines are large, the quantity of the detergent is large due to the fact that the cleaning rate has certain requirements on the concentration of the washing liquid, and the quantity of the generated sewage is large.

To analyze the reasons why the above three types of washing machines have unsatisfactory cleaning performance, it is necessary to know the cleaning and decontaminating principle of the washing machine. The washing machine essentially pulls dirt from the surface of the laundry and fiber pores by the combined action of chemical and mechanical forces. In the process, the combined action of water, detergent and mechanical force reduces, weakens and destroys the surface adhesion, mechanical adhesion, intermolecular attraction bonding and chemical bonding formed between dirt and fabrics, so that the dirt is separated from the clothes, and the aim of cleaning is fulfilled. The main factors affecting the washing effect are three: the concentration of the washing liquid, the temperature of the washing liquid, and the mechanical force during the washing process, wherein the mechanical force plays an important role. The mechanical force in the washing process is a complex force system, and among various mechanical forces constituting the force system, the friction force between cloth and cloth has the most remarkable influence on the cleanliness, and the friction force between cloth and plastic, and the bending force, the impact force, the friction force between cloth and water and the stretching force are sequentially adopted. (washing machine principle and maintenance technology, Chenhao, Bao and peace edition, 8 months first edition 1999 Henan science and technology Press). Obviously, the washing and decontamination principles of the above three types of washing machines determine the degree of cleanliness, and among them, the agitator type washing machine is relatively high.

Based on the knowledge of the above principle, many household washing machine enterprises are improving the existing impeller type washing machine, developing various "new water flow" and "hand rubbing" washing machines, and trying to increase the friction force between cloth and between cloth and plastic to improve the cleanliness. However, the above-mentioned "hand-rubbing" washing machines do not change the basic principle of the conventional pulsator type washing machine, i.e., the washing liquid forms a vortex to wash the laundry, so that it is impossible to form a true "hand-rubbing" washing machine, and thus the degree of washing is not satisfactory.

Chinese patent CN86207893, 88106749 made a beneficial attempt to increase the friction between cloth and plastic to improve the cleanliness: the former rubs and washes the clothes on the washboard reciprocally through a swinging head, the latter rubs and washes the clothes on the lower washboard reciprocally through a left-right swinging upper washboard, both can improve the cleaning degree, but the former has low efficiency, the latter has a complex structure and is not beautiful, and the automation degree of the former is not high, and the former can not realize that one machine can complete washing, bleaching and removing, and is difficult to adapt to the requirements of the public.

The closest existing technology is a full-automatic cylinder (tub) set impeller type washing machine. It is composed of an upper cover, a lower box body, a washing barrel, a water containing channel, a wave wheel, a water supply and drainage system, a washing system, a program controller, a transmission mechanism, a motor and the like which are arranged in the lower box body and sleeved together; wherein, the impeller is arranged in the washing barrel through a hole in the center of the washing barrel, and is driven by the motor through the transmission mechanism to complete washing. Similarly, the degree of cleaning was poor, and the amount of water and detergent used was large.

(III) the invention content:

the present invention is to provide a washing machine having high washing efficiency and high automation degree by avoiding the disadvantages of the prior art.

The technical solution of the invention is as follows:

a rubbing washing machine comprises an upper cover, a lower box body, a water supply and drainage system, a washing system, a program controller, a transmission mechanism, a motor and the like; wherein,

the washing system mainly comprises a washing barrel arranged in the lower box body, a wave wheel positioned in the washing barrel and the like;

the water supply and drainage system mainly comprises a water inlet pipe, a water drainage pipe, a water inlet electromagnetic valve, a water level pressure switch and a water drainage electromagnetic valve;

the program controller is arranged on the upper cover, controls the rotation direction and the running time of the motor through a circuit, and controls the action of each electromagnetic valve;

the motor is arranged in the lower box body, and transmits power to the impeller through the transmission mechanism so as to drive the impeller to run;

the method is characterized in that:

the upper cover is also provided with an upper washing mechanism which mainly comprises an upper impeller which is arranged in the upper cover and can be lifted up and down, an upper transmission mechanism, an upper washing motor which is used for driving the upper impeller to rotate through the upper transmission mechanism, an upper lifting motor which is used for driving the upper impeller to be lifted up and down, and the like,

the lower impeller is arranged at the bottom of the washing barrel and has the same axis line with the washing barrel;

the diameters of the upper impeller and the lower impeller are equal and are circular impellers, when the upper cover is covered, the central lines of the upper impeller and the lower impeller are both positioned on the central axis of the washing barrel, and the upper impeller and the lower impeller rotate in a single direction and in a reverse direction during work;

the impeller shaft of the upper impeller is composed of a plurality of sections of sleeves and is of a pull rod type structure, moving pairs which can only do relative motion along the axial direction are arranged among the sleeves, a spring is arranged in the impeller shaft, so that the upper impeller can press clothes to rub when in work, the upper lifting motor drives the upper impeller to lift up and down along the axis of the upper impeller through a transmission part, and the upper washing motor drives the upper impeller to rotate through the transmission part.

In the technical scheme, the rubbing structure of the upper and lower double-wave wheels with the same diameter and opposite rotation directions is adopted, so that the friction force between the cloth and the plastic in the washing process and the friction force between the cloth and the plastic are greatly enhanced, the 'hand rubbing type' in the true sense is realized, and the cleaning degree is obviously improved.

The further technical scheme is as follows:

the upper impeller and the lower impeller are disc-shaped concave impellers with the diameter slightly smaller than the inner diameter of the bottom of the washing barrel, the outer space of the working surface of each impeller forms a cone with the apex angle of 166 plus 170 degrees, namely, the included angle between any radial line from the center and the horizontal plane passing through the center on the working surface of each impeller is 5-7 degrees, a plurality of ribs which extend from the center to the periphery and protrude out of the surface of each impeller are uniformly distributed on the working surfaces of the two impellers, and the ribs are linear, arc or involute.

This technical scheme makes and forms a cavity between the working face of last impeller and lower impeller, the clothing is located this cavity during washing, the frictional force when washing has not only been increased to the effect of muscle, simultaneously, form the guide way between the adjacent muscle, the clothing is when washing, the higher authority of clothing contacts the one side of last impeller promptly and moves along the guide way on last impeller surface under the effect of frictional force, the one side of impeller moves along the guide way on impeller surface under the effect of frictional force under the clothing is contacted promptly, because the coaxial antiport of two impellers, the clothing that is located this cavity is forced to be accomplished automatic upset, thereby guaranteed that the washing is even and clean.

When the ribs are in an involute shape, the clothes have the best turnover effect.

The further technical scheme is as follows:

the washing barrel is of an integrated structure with a closed bottom, the lower impeller is fixed on the inner surface of the bottom of the washing barrel, and the lower surface of the washing barrel is connected with the washing shaft.

According to the technical scheme, the washing barrel is of a bottom closed structure, so that the possibility of leakage caused by aging of a sealing piece for installing the impeller in the prior art is avoided.

Still further technical scheme does:

the washing shaft connected with the washing barrel is provided with two overrunning clutches with opposite no-load directions, and the outer ring of the clutch and the output shaft of the lower washing motor are respectively driven by two transmission mechanisms with different transmission ratios.

This technical scheme has conveniently realized only changing the positive and negative direction of motor and has turned to, and the washtub can realize two kinds of working methods together with the lower impeller that is fixed in it: i.e. low speed rotation in one direction for washing and high speed rotation in the other direction for dewatering. Thereby realizing the function of double barrel with single barrel. This is not easily imaginable to the skilled person, and it is simple and cost-effective.

Considering that the inner diameter of the upper part of the washing tub should be increased with the height thereof in order to facilitate the dehydration, the inner wall thereof may also have a plurality of flow guide ribs.

The invention conveniently realizes multiple functions of washing, bleaching and removing by one machine and has higher automation degree. The working process is briefly described as follows: 1. water inflow: putting clothes and detergent into the clothes washing machine, closing the upper cover, switching on a power supply, opening a water inlet switch of the program controller, opening a water inlet electromagnetic valve to feed water, releasing the upper impeller by the upper lifting motor, extruding the upper impeller on the clothes on the lower impeller under the combined action of the elastic force of the spring, and stopping water inlet when the water is fed to a certain height (the water inlet amount only needs to soak the clothes extruded by the upper and lower impellers, so the quantity is less), turning off the water inlet electromagnetic valve by the program controller to feed water; 2. washing: the time program controller simultaneously energizes the upper and lower washing motors, the two motors respectively drive the upper and lower impellers to rotate coaxially and reversely through the transmission mechanism to rub and wash clothes, the clothes are positioned between the two impellers to automatically turn over, and the program controller gives out electric signals to stop the rotation of the upper and lower motors when the washing is up to a set time. 3. And (3) dehydrating: at the moment, the program controller gives an electric signal to open the water discharge electromagnetic valve, and simultaneously, the program controller gives an electric signal to enable the lower washing motor to rotate reversely (opposite to the washing direction), the lower washing motor drives the washing barrel to rotate reversely at a high speed (opposite to the washing direction) through the transmission mechanism, and under the action of centrifugal force, water is separated from the washing barrel and is discharged through the water outlet. And after the dehydration is finished, the upper lifting motor works to drive the upper impeller to lift. The full-automatic washing, bleaching and dewatering process can be completed by repeating the steps of water inlet, washing and dewatering through the process controller, which is also the working mode of the existing full-automatic cylinder (barrel) type impeller type washing machine and is not described in detail here.

The main advantages of the invention are as follows:

the double-impeller rubbing structure is adopted, the washing mode is fundamentally changed, the friction force between the cloth and the plastic and the friction force between the cloth and the plastic in the washing process are greatly enhanced, the 'hand rubbing type' is realized in the true sense, and the cleaning degree is improved.

The lower impeller is fixed on the inner surface of the bottom of the washing barrel, and the washing barrel adopts a bottom closed structure and has no leakage absolutely.

The washing shaft of the washing barrel is driven by the same lower washing motor through two overrunning clutches which are fixed on the washing shaft and have opposite no-load directions and two transmission mechanisms with different transmission ratios, so that two working modes of washing and dewatering can be realized by only changing the positive and negative rotation directions of the motor, and the function of double barrels is realized by using a single barrel. Simple structure and low cost.

In the washing process, the clothes are in a squeezed state, the amount of the required washing liquid is greatly reduced, and the consumption of the washing agent and the water is greatly saved. Meanwhile, the generation amount of washing sewage is reduced.

The washing time is reduced due to the improved cleaning degree, thereby saving the electricity consumption.

The invention is characterized in that, although the structure form is close to the full-automatic impeller type washing machine, the washing machine and the full-automatic impeller type washing machine can share the lower box body, the water supply and drainage system, the washing system, the program controller, part of the transmission mechanism, the motor and the like, and the washing machine and the full-automatic impeller type washing machine also have the washing barrel and the impeller, only the water containing barrel is removed, the upper washing system comprising the upper motor and the upper impeller is added, the transmission mechanism is changed, but the washing machine is completely different from the washing principle, the friction force between the cloth and the friction force between the cloth and the plastic are enhanced in the washing process through rubbing, and the washing machine is characterized in that the structure, the motion form and the action of the impeller are completely different, so that the washing machine has higher washing degree. This also facilitates consumer acceptance and re-production of existing washing machine plants.

(IV) description of the drawings:

FIG. 1 is a schematic view of example 1 of the present invention;

FIG. 2 is a schematic view of a lower pulsator in embodiment 1 of the present invention;

FIG. 3 is a view A-A of the lower pulsator of FIG. 2;

FIG. 4 is a schematic view of the upper impeller shaft of embodiment 1 of the present invention;

the numbers in the figure are respectively: 1. washing barrel, 2, lower impeller, 3, washing belt pulley, 4, washing overrunning clutch 5, transmission belt, 6, washing belt pulley, 7, lower washing motor output shaft, 8, lower box, 9, lower washing motor, 10, dewatering belt pulley, 11, bearing, 12, washing shaft, 13, dewatering overrunning clutch, 14, dewatering belt pulley, 15, waterproof partition, 16, water outlet, 17, water discharge electromagnetic valve, 18, ball float valve, 19, overflow port, 20, water level pressure switch, 21, twist spring, 22, water inlet pipe, 23, upper cover, 24, water inlet pipe, 25, belt pulley, 26, water inlet electromagnetic valve and water inlet distributor, 27, water inlet, 28, contact switch, 29, collision block, 30, spring, 31, pulley, 32, program controller, 33, guy cable, 34, ascending and descending motor, 35, brake, 36, upper impeller, 37, ascending and descending motor output shaft, 6, washing belt pulley, 7, lower washing motor output shaft, lower box, 9, lower washing motor, 10, water level pressure, 38. Bearing, 39, upper impeller shaft 40, transmission belt, 41, upper washing motor, 42, overrunning clutch, 43 washing belt pulley

(V) specific embodiment:

the following describes in further detail embodiments of the present invention with reference to the accompanying drawings.

Referring to the drawings, the embodiment of the present invention includes two major parts, an upper cover 23 and a lower case 8, wherein,

a washing barrel 1, a lower washing motor 9 and the like are arranged in a lower box body 8, the washing barrel 1 is of an integrated structure with a closed bottom, a disc-shaped concave impeller with the diameter slightly smaller than the inner diameter of the bottom of the washing barrel is fixed on the inner surface of the bottom, the included angle between any radial line from the center and a horizontal plane passing through the center on the working surface of the impeller is 7 degrees, a plurality of ribs which are in involute shape and protrude out of the surface of the impeller are evenly distributed on the working surface of the impeller, a lower washing shaft 12 is connected below the washing barrel 1, the lower end of the shaft is arranged on a bottom plate through a bearing 11, two clutches 4 and 13 with mutually opposite idle directions are also arranged on the shaft, a washing belt pulley 3 and a dewatering belt pulley 14 are respectively arranged on the outer rings of the two overrunning clutches, a belt pulley 6 is arranged on an output shaft 7 of the lower washing motor 9 and is connected with the washing belt, the output shaft 7 of the lower washing motor 9 is also provided with a belt pulley 10 and is connected with a dewatering belt pulley 14 through a transmission belt. The two transmission mechanisms have different transmission ratios. The above mechanisms are all located in a closed space formed by the waterproof partition 15 to prevent water from entering. The lower box 1 is also provided with a water discharge electromagnetic valve 17, a water discharge port 16, an overflow port 19, a float valve 18, a water level pressure switch 19 and the like.

An upper impeller 36 capable of ascending and descending up and down, an upper washing motor 41 for driving the upper impeller to rotate, an ascending and descending motor 34 for driving the upper impeller to ascend and descend up and down and the like are arranged in the upper cover 23, the diameter of the upper impeller 26 is equal to that of the lower impeller 2, the shape of the working surface of the upper impeller is also the same as that of the lower impeller 2, when the upper cover 23 is covered, the central lines of the upper impeller and the lower impeller are both positioned on the central axis of the washing barrel 1, and the rotating directions of the upper impeller and the lower impeller are opposite during working; the impeller shaft 39 of the upper impeller is composed of a plurality of sections of sleeves, a moving pair which only can do relative axial movement is arranged between the sleeves, the impeller shaft is integrally in a multi-section telescopic structure, so that the upper impeller 36 can lift up and down along the axis, the lifting motor 34 drives the upper impeller 36 to lift up and down along the axis through the inhaul cable 33 wound on the pulley 31, and the upper washing motor 41 drives the upper impeller shaft 39 to rotate through the washing belt pulley 43, the transmission belt 40 and the belt pulley 25. The upper impeller shaft is also internally provided with a pressure spring 30, so that the kneading force of the upper impeller can be adjusted according to the quantity of clothes. In addition, the upper cover 23 is also provided with a water inlet 27, a water inlet electromagnetic valve and water inlet distributor 30,

water inlet pipes

22 and 24, a program controller 32, a contact switch 28, a collision block 29 and a brake band-type brake 35. The collision block 29 is connected with a pull rope 33, when the upper impeller is lifted to the right position, the collision block 29 touches the contact switch 28, and the process controller 32 and the brake band-type brake 35 control the upper lifting motor 34 to stop working.

In the embodiment, the rubbing structure is formed by the upper and lower double-wave wheels with the same diameter and opposite rotation directions, so that the friction force between the cloth and the plastic in the washing process is greatly enhanced, the 'hand rubbing type' in the true sense is realized, and the cleaning degree is obviously improved.

The working process of the embodiment of the invention is as follows: 1. and (3) washing process: put in clothes and detergent, close the upper cover, open the washing switch of the program controller 32, open the water inlet electromagnetic valve 26 to feed water, at the same time, the upper lift motor 34 releases the upper pulsator 36 to descend along its axis by means of the traction cable 33 passing around the pulley 31, under the combined action of the spring force, the upper impeller extrudes on the clothes on the lower impeller, when the water is fed to a certain height, the water level pressure switch 20 gives out an electric signal, the program controller 32 turns off the water inlet electromagnetic valve 26 to stop feeding the water, simultaneously, the washing motor 9 under the control of the program controller 32 drives the belt pulley 3 through the belt pulley 6 and the transmission belt 5 and drives the washing barrel 1 to rotate towards one direction through the overrunning clutch 4, the program controller 32 controls the upper washing motor 41 to drive the pulley 25 mounted on the upper impeller shaft through the overrunning clutch 42, the upper washing motor pulley 43 and the transmission belt 40, thereby driving the upper impeller to rotate in the other direction. The upper and lower wave wheels rotate coaxially and reversely to rub and wash clothes, the clothes are automatically turned over between the two wave wheels, and the program controller gives out electric signals to make the clothes go up,

The lower washing motor stops rotating. 2. And (3) dehydrating: the water discharge electromagnetic valve 17 is opened, at the same time, the program controller 32 gives an electric signal to make the lower motor 9 rotate reversely (opposite to the washing direction), the lower motor 3 drives the belt pulley 14 through the dewatering belt pulley 10 and drives the washing barrel 1 to rotate reversely at high speed (opposite to the washing direction) through the overrunning clutch 13, and under the action of centrifugal force, water is discharged and discharged through the water gap 16 and the overflow port 19. The full-automatic washing, bleaching and dewatering process can be completed by repeating the steps of water feeding, washing and dewatering through the process controller.

The structure of the embodiment 2 is basically the same as that of the above embodiment, with the following differences: 1. in the impeller in the embodiment, the included angle between any radial line from the center on the working surface of the impeller and a horizontal plane passing through the center is 5 degrees; 2. arc-shaped ribs are uniformly distributed on the impeller in the embodiment; 3. the inner diameter of the upper part of the washing barrel in the embodiment is increased along with the height of the washing barrel, and the inner wall of the washing barrel is provided with a plurality of flow guide ribs; 4. in this embodiment, the drain solenoid valve is omitted: 5. in the embodiment, two internal tooth ratchet wheel type overrunning clutches with mutually opposite no-load directions are arranged on an output shaft of a lower washing motor, and outer rings of the two overrunning clutches are respectively connected with two belt pulleys (a washing belt pulley and a dewatering belt pulley) with different diameters fixedly arranged on a washing shaft through two transmission belts. Otherwise, it is identical.

The present invention has several embodiments, for example, the upper pulsator driving structure in the embodiment adopts a washing belt wheel fixed on the outer ring of the overrunning clutch on the output shaft of the upper washing motor, and the belt wheel is fixed on the outer casing of the upper pulsator shaft through belt transmission, and the outer casing drives the casing step by step through key connection to drive the upper pulsator connected to the innermost casing to rotate. The above-described specific structure is not limited thereto, and the detailed description thereof is omitted. Meanwhile, it should be noted that the specific structures of the water level pressure switch 20, the program controller 32, the water inlet and outlet solenoid valves, etc. in the embodiment of the present invention are known to those skilled in the art, and therefore, the detailed description thereof is omitted.

Claims

1. A rubbing washing machine comprises an upper cover, a lower box body, a water supply and drainage system, a washing system, a program controller, a transmission mechanism, a motor and the like,

the water supply and drainage system mainly comprises a water inlet pipe, a water drainage pipe, a water inlet electromagnetic valve, a water level pressure switch and the like;

the method is characterized in that:

the upper impeller is a concave impeller with the diameter equal to that of the lower impeller, when the upper cover is covered, the central lines of the upper impeller and the lower impeller are both positioned on the central axis of the washing barrel, and the upper impeller and the lower impeller rotate in a single direction and in a reverse direction when the washing barrel works;

the impeller shaft of the upper impeller is composed of a plurality of sections of sleeves, a moving pair which can only do relative axial movement is arranged between the sleeves, the upper lifting motor drives the upper impeller to lift up and down along the axis of the upper impeller through a transmission part, and the upper washing motor drives the upper impeller to rotate through the transmission part.

2. A kneading type washing machine according to claim 1, characterized in that: the washing barrel is of an integrated structure with a closed bottom, the lower impeller is a concave impeller with the diameter slightly smaller than the inner diameter of the bottom of the washing barrel, the concave impeller is fixed on the inner surface of the bottom of the washing barrel, and a washing shaft is connected below the washing barrel.

3. A kneading type washing machine according to claim 1, characterized in that: the upper impeller and the lower impeller are disc-shaped concave impellers with the diameter slightly smaller than the inner diameter of the bottom of the washing barrel, the outer space of the working surface of the upper impeller and the lower impeller are respectively provided with a cone with the cone apex angle of 166 plus 170 degrees, namely, the included angle between any radial line from the center and the horizontal plane passing through the center on the working surface of the impeller is 5-7 degrees, a plurality of ribs which extend from the center to the periphery and protrude out of the surface of the impeller are uniformly distributed on the two impellers, and the ribs are in a linear shape, an arc shape or an involute shape.

4. A kneading type washing machine according to claim 1, characterized in that: the upper impeller and the lower impeller are uniformly distributed with involute ribs.

5. A kneading type washing machine according to claim 1, characterized in that: and a spring is arranged on the upper wave wheel shaft.

6. A kneading type washing machine according to claim 2, characterized in that: two overrunning clutches with mutually opposite idle directions are arranged on a washing shaft connected with the washing barrel, and the outer ring of the clutch and the output shaft of the lower motor are respectively driven by two transmission mechanisms with different transmission ratios.

7. A kneading type washing machine according to claim 6, characterized in that: the inner diameter of the upper part of the washing barrel is increased along with the height of the washing barrel, and the inner wall of the washing barrel is provided with a plurality of flow guide ribs.

8. A kneading type washing machine according to claim 7, characterized in that: the upper impeller and the lower impeller are disc-shaped concave impellers with the diameter slightly smaller than the inner diameter of the bottom of the washing barrel, the outer space of the working surface of the upper impeller and the lower impeller are respectively provided with a cone with the cone apex angle of 166 plus 170 degrees, namely, the included angle between any radial line from the center and the horizontal plane passing through the center on the working surface of the impeller is 5-7 degrees, a plurality of ribs which extend from the center to the periphery and protrude out of the surface of the impeller are uniformly distributed on the two impellers, and the ribs are in a linear shape, an arc shape or an involute shape; and a spring is arranged on the upper wave wheel shaft.