Disc Brush for Power Scrubber and Power Scrubber Having Such a Disc Brush

The subject matter described herein relates to power tools, and more particularly relates to a disc brush for a power scrubber; in addition, the subject matter described herein further relates to a power scrubber having such a disc brush.

Driven by the advancement of industrialization, a growing variety of power tools have emerged to implement various tasks, e.g., a power scrubber. An existing power scrubber generally comprises a housing, an electric motor, and a disc brush, where the electric motor actuates the disc brush to spin, so that the spinning disc brush scrubs a to-be-cleaned object or surface. The power scrubber significantly facilitates a user's cleaning work, for example, washing a car, or cleaning a kitchen item, a floor surface, or a wall surface. To enhance user experience, an existing power scrubber adopts a structure comprising an inner disc body and an outer disc body; opposite rotation between the inner disc body and the outer disc body may offset a fraction of the centrifugal force, which mitigates a movement tendency of the disc brush, thereby improving grip comfort for the operating user. However, the bristles on the inner and outer disc bodies of the existing power scrubber usually have identical settings, i.e., same hardness and length, so that they have substantially equal dirt scrubbing capabilities. The bristles with the same scrubbing capabilities cannot satisfy scrubbing requirements posed by varying degrees of dirtiness on different parts of a to-be-cleaned object or surface, so that the user needs to change the disc brush or scrub the dirt manually.

To overcome the above and other drawbacks in conventional technologies, the present disclosure provides a disc brush for a power scrubber; a user may choose to use a softer scrubbing body or a harder scrubbing body to scrub dirt dependent on a degree of dirtiness without a need of changing the disc brush, which improves user experience.

A disc brush for a power scrubber as described herein comprises an inner disc body and an outer disc body, the inner disc body being disposed at an inner periphery of the outer disc body, a scrubbing body being set at an underside of the inner disc body and at an underside of the outer disc body, respectively, wherein the scrubbing bodies are differentiated into at least two degrees of hardness, a softer scrubbing body being set with a height not lower than that of a harder scrubbing body.

In some implementations, the scrubbing bodies are made of a same material, or the scrubbing bodies are made of different materials.

In some implementations, the scrubbing bodies are formed by a softer sponge and a harder sponge, respectively, the softer sponge being set with a height larger than that of the harder sponge.

In some implementations, the scrubbing bodies are formed by a softer bristle bundle and a harder bristle bundle, respectively, the softer bristle bundle being set with a height larger than that of the harder bristle bundle.

In some implementations, the softer bristle bundle and the harder bristle bundle are formed of a plurality of bristles, respectively, a diameter of the bristles forming the softer bristle bundle being smaller than that of the bristles forming the harder bristle bundle.

In some implementations, the softer bristle bundle and the harder bristle bundle are formed of a plurality of bristles, respectively, the bristles being formed into a wave shape.

In some implementations, the softer scrubbing body is set with a height larger than that of the harder scrubbing body, height difference Δtherebetween ranging from 1 mm to 10 mm.

In some implementations, the scrubbing bodies are formed by a softer scrubbing body disposed at the underside of the inner disc body and a harder scrubbing body disposed at the underside of the outer disc body; or, the scrubbing bodies are formed by a harder scrubbing body disposed at the underside of the inner disc body and a softer scrubbing body disposed at the underside of the outer disc body.

In some implementations, a recessed cavity configured to receive the inner disc body is provided at the inner periphery of the outer disc body, the inner disc body, when being assembled with the outer disc body, being located in the recessed cavity, the undersides of the inner disc body and the outer disc body assembled together being set flush with each other.

The present disclosure further provides a power scrubber, comprising a housing, an electric motor, and a drive assembly, the electric motor and the drive assembly being disposed inside the housing, the drive assembly comprising an inner shaft and an outer shaft sleeved outside the inner shaft, wherein the power scrubber further comprises the disc brush described supra, the disc brush being disposed outside the housing, the inner disc body being removably connected to the inner shaft, the outer disc body being removably connected to the outer shaft, the electric motor actuating, via the drive assembly, the inner disc body and the outer disc body to rotate in opposite directions or in a same direction.

With the technical solutions described supra, the present disclosure offers the following benefits:

1. According to the disc brush described herein, a scrubbing body is set at the underside of the inner disc body and the underside of the outer disc body, respectively, the scrubbing bodies being differentiated into at least two degrees of hardness, a softer scrubbing body being set with a height not lower than that of a harder scrubbing body. A user may choose to use the softer scrubbing body or the harder scrubbing body to scrub dirt dependent on a degree of dirtiness without a need to change the disc brush, which improves user experience. By setting the softer scrubbing body with a height larger than that of the harder scrubbing body, when the operating user exerts a force against the disc brush so as to scrub a to-be-cleaned object or surface with the scrubbing bodies, the softer scrubbing body is deformed to a larger extent, while the harder scrubbing body is deformed less. Since the softer scrubbing body is higher than the harder scrubbing body, the more deformed softer scrubbing body and the less deformed harder scrubbing body can both access the to-be-cleaned object or surface to implement effective scrubbing. The user may vary the scrubbing forces of the softer scrubbing body and the harder scrubbing body by varying the force applied against the disc brush; as such, the user may impose a rational force against the disc brush according to scrubbing requirements.

2. The softer scrubbing body and the harder scrubbing body may be made of a same material or may be made of different materials. In a case that the scrubbing bodies are made of different materials, the scrubbing bodies of different materials serve different purposes in scrubbing a to-be-cleaned object or surface. For example, a sponge may generate bubbles first, and then the bristle bundle serves to scrub, whereby a better cleaning effect is achieved.

3. The scrubbing bodies may adopt sponges; in this case, the softer sponge is set with a height greater than that of the harder sponge. The softer sponge and the harder sponge may be made of a same sponge material. The harder sponge, which is more compact than the softer sponge, is harder than the latter. When the operating user applies a force against the disc brush, the softer sponge is more deformed under stress, while the harder sponge is less deformed, in which case the softer and harder sponges can both scrub the to-be-cleaned object or surface effectively. The softer sponge may serve to generate bubbles, while the harder sponge may serve to scrub and remove dirt or debris.

4. The scrubbing bodies may adopt bristle bundles. In this case, the softer bristle bundle is set with a height larger than that of the harder bristle; the softer bristle bundle and the harder bristle bundle may be made of a same material such as plastics or nylon; in a case that the softer bristle bundle and the harder bristle bundle are consistent in thickness, the longer bristle bundle is softer, while the shorter bristle bundle is harder. When the operating user exerts a force against the disc brush, the softer bristle bundle is deformed to a larger extent, while the harder bristle bundle is deformed less, so that the softer bristle bundle and the harder bristle bundle can both serve to scrub the to-be-cleaned object or surface effectively. For example, upon scrubbing, the harder bristle bundle may be used first to scrub agglomerated stains, and then the softer bristle bundle serves to further sweep residual spotted stains.

5. The softer bristle bundle and the harder bristle bundle are both formed of bristles. For the bristles made of a same material, the bristles with a smaller diameter are softer, while the bristles with a larger diameter are harder. In a case that the bristles of the softer bristle bundle and the bristles of the harder bristle bundle vary in height, thickness is a further variable that enlarges the difference between their hardnesses.

6. The bristles forming the bristle bundles are configured with a wave form, so that the bristle bundles formed by a plurality of wave-like bristles maintain a fluffy state with liquid absorbed, which prevents the bristles in the same bundle from being agglomerated due to absorption of water, thereby enhancing the effect of the bristle bundles cleaning the to-be-cleaned object or surface.

7. The softer scrubbing body is set with a height greater than that of the harder scrubbing body; by rationally setting the height difference between the softer scrubbing body and the harder scrubbing body, the softer and harder scrubbing bodies can both scrub the to-be-cleaned object or surface effectively during operating. If the height difference Δis too small, the softer scrubbing body is given an insufficient contact force against the to-be-cleaned object or surface when the disc brush is stressed, so that the softer scrubbing body cannot achieve effective scrubbing with respect to the to-be-cleaned object or surface. If the height difference Δis too large, the harder scrubbing body is given an insufficient contact force against the to-be-cleaned object or surface when the disc brush is stressed, so that the harder scrubbing body cannot achieve effective scrubbing with respect to the to-be-cleaned object or surface.

8. The scrubbing bodies at the undersides of the inner disc body and outer disc body may adopt a scrubbing structure that is softer inside and harder outside or a scrubbing structure that is harder inside and softer outside; the scrubbing bodies set at the undersides of the inner disc body and outer disc body may be made of a same material with a same hardness, which facilitates enhancement of the efficiency of manufacturing the inner disc body and outer disc body.

9. When the inner disc body and the outer disc body are assembled together, the inner disc body is received in the recessed cavity of the outer disc body, so that the underside of the inner disc body may be set flush with the underside of the outer disc body; in this way, the lower end of the softer scrubbing body may be set lower than the lower end of the harder scrubbing body, whereby the softer scrubbing body and the harder scrubbing body, when operating, can both give an effective scrubbing to the to-be-cleaned object or surface.

In the drawings:—disc brush;—inner disc body;—fit-in hole;—fit-in recess;—turnbuckle;—arcuate segment;—linear segment;—finger groove;—outer disc body;—recessed cavity;—connecting hole;—female thread;—water discharge channel;—scrubbing body;—softer bristle bundle;—harder bristle bundle;—bristles;—softer sponge;—harder sponge;

Hereinafter, the present disclosure will be further explained through example implementations with reference to the accompanying drawings. It would be understood that the orientational or positional relationships indicated by the terms “upper,” “lower,” “left,” “right,” “longitudinal,” “transverse,” “inner,” “outer,” “vertical,” “horizontal,” “top,” and “bottom,” etc. are orientational and positional relationships based on the drawings, which are intended only for facilitating description of the disclosure and simplifying relevant illustrations, not for indicating or implying that the devices or elements compulsorily possess those specific orientations and are compulsorily configured and operated with those specific orientations; therefore, such terms should not be construed as limitations to the disclosure.

Referring to, a disc brushfor a power scrubber according to a first implementation of the present disclosure comprises an inner disc bodyand an outer disc body, the inner disc bodybeing disposed at an inner periphery of the outer disc body, a scrubbing bodybeing set at an underside of the inner disc bodyand an underside of the outer disc body, respectively; the scrubbing bodiesare differentiated into at least two degrees of hardness, a softer scrubbing body being set with a height not lower than that of a harder scrubbing body.

A user may choose to use the softer scrubbing body or the harder scrubbing body to scrub dirt dependent on a degree of dirtiness without a need to change the disc brush, which improves user experience. By setting the softer scrubbing body with a height larger than that of the harder scrubbing body, when the operating user exerts a force against the disc brushso that the scrubbing bodiesscrub a to-be-cleaned object or surface, the softer scrubbing body is deformed to a larger extent, while the harder scrubbing body is deformed less. Since the softer scrubbing body is higher than the harder scrubbing body, the more deformed softer scrubbing body and the less deformed harder scrubbing body can both access the to-be-cleaned object or surface to implement effective scrubbing. The user may vary the scrubbing forces of the soft scrubbing body and the hard scrubbing body by varying the force applied against the disc brush; as such, the user may impose a rational force against the disc brushaccording to scrubbing requirements.

Referring to, in this implementation, the scrubbing bodiesat the underside of the disc brushadopt a bristle structure made of a same material. Specifically, the scrubbing bodiesare formed by a softer bristle bundleand a harder bristle bundle, respectively, a height of the softer bristle bundlebeing exemplarily larger than that of the harder bristle bundle. In an exemplary solution of this implementation, a plurality of softer bristle bundlesdistributed at even intervals are set on the underside of the inner disc body, and a plurality of harder bristle bundlesdistributed at even intervals are set on the underside of the outer disc body, i.e., the bristle bundles at the underside of the disc brushare distributed in a manner of softer inside and harder outside. After the disc brushis assembled to the power scrubber, the underside of the inner disc bodyand the underside of the outer disc bodyare substantially flush with each other; correspondingly, a lower end of the softer bristle bundleis lower than a lower end of the harder bristle bundlewith a height difference Δtherebetween. As an alternative solution of this implementation, the underside of the inner disc bodymay be set with a plurality of harder bristle bundlesdistributed at even intervals, and the underside of the outer disc bodymay be set with a plurality of softer bristle bundlesdistributed at even intervals, i.e., the bristle bundles at the underside of the disc brushare distributed in a manner of harder inside and softer outside.

In this implementation, the softer bristle bundleand the harder bristle bundleare both formed of a plurality of bristles, and the bristles of the softer bristle bundleand the bristles of the harder bristle bundleare made of a same type of plastics or nylon or the like. In addition, the diameter of the bristles forming the softer bristle bundleis consistent with that of the bristles forming the harder bristle bundle. With the same diameter, longer bristles are softer while shorter bristles are harder, whereby the softer bristle bundlesand the harder bristle bundles, which have different heights, are contributed different hardnesses. Specifically, the root of the softer bristle bundleis fixedly implanted into the underside of the inner disc body, and the root of the harder bristle bundleis fixedly implemented into the underside of the outer disc body. Height Hof the softer bristle bundlerefers to downward extension distance of the softer bristle bundlerelative to the underside of the inner disc body, and height Hof the harder bristle bundlerefers to downward extension distance of the harder bristle bundlerelative to the underside of the outer disc body, height Hof the softer bristle bundlebeing greater than height Hof the harder bristle bundle, H-Hbeing represented by Δ.

In this implementation, 1 mm≤Δ≤10 mm. Specifically, height Hof the softer bristle bundleis about 24 mm, and height Hof the harder bristle bundleis about 20 mm; correspondingly, the height difference Δbetween the softer bristle bundleand the harder bristle bundleis about 4 mm. As an alternative solution to this implementation, height Hof the softer bristle bundlemay also be set to other rational values such as 20 mm, 21 mm, 22 mm, 23 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, and 30 mm, height Hof the harder bristle bundlemay also be set to other rational values such as 16 mm, 17 mm, 18 mm, 19 mm, 21 mm, 22 mm, 23 mm, 24 mm, and 25 mm, and height difference Δh between the softer bristle bundleand the harder bristle bundlemay also be set to other rational values such as 1 mm, 2 mm, 3 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, and 10 mm.

If liquid is existent in the way of scrubbing, the bristle bundles would absorb the liquid, while the liquid temporarily stored in the bristle bundles would cause agglomeration of the bristlesin the same bristle bundle, which deteriorates the scrubbing effect of the bristle bundles. On this basis, with reference to, in this implementation, the bristles forming the softer bristle bundleand the bristles forming the harder bristle bundleare exemplarily configured with a wave form, so that the bristle bundle formed by a plurality of wave-like bristlescan still maintain a fluffy state with liquid absorbed, which ensures the effect of the bristle bundle scrubbing the to-be-cleaned object or surface. As an alternative solution to this implementation, the bristlesforming the softer bristle bundlemay adopt straight bristles, and the bristles forming the harder bristle bundlemay also adopt straight bristles.

In this implementation, to better satisfy scrubbing requirements, two inner disc bodiesand one outer disc bodyare provided. The softer bristle bundlesat the undersides of the two inner disc bodieshave different lengths, which results in different hardnesses. Any of the inner disc bodiescan be combined with the outer disc bodyto form the disc brush, which facilitates the user to choose one for assembly according to actual scrubbing requirements, so that the power scrubber can satisfy various purposes, reducing purchase costs while improving user experience. To facilitate user identification, the bristle bundles with different degrees of hardness are indicated by different colors. As an alternative solution to this implementation, only one inner disc bodymay be provided; in this case, two outer disc bodiesmay be provided. Of course, other rational numbers of the inner disc bodiesand the outer disc bodies, such as one, two, three and four, may be provided, respectively; the number of the inner disc bodiesas provided may be identical to or different from the number of the outer disc bodies.

Referring to, to set the bristle bundles, a plurality of orifices distributed at even intervals are provided at the underside of the inner disc bodyand the underside of the outer disc body, respectively, and the roots of the bristle bundles are securely implanted in the orifices. Referring to, a recessed cavityrecessed inwardly upward from the underside is provided at the inner periphery of the outer disc body. Referring to, when the inner disc bodyand the outer disc bodyare assembled together, the inner disc bodyis received in the recessed cavity, the underside of the inner disc bodyand the underside of the outer disc bodybeing set substantially flush with each other.

Referring to, this implementation further provides a power scrubber, comprising a housing, an electric motor, a drive assembly, and the disc brushdescribed supra, the electric motorand the drive assemblybeing disposed inside the housing, the drive assemblycomprising an inner shaftand an outer shaftsleeved outside the inner shaft, the inner disc bodybeing removably connected to the inner shaft, the outer disc bodybeing removably connected to the outer shaft, the electric motoractuating, via the drive assembly, the inner disc bodyand the outer disc bodyto rotate in opposite directions. Opposite rotation between the inner disc bodyand the outer disc bodymay offset a fraction of centrifugal forces, thereby mitigating a movement tendency of the power scrubber when the disc brush discis rotating, which can reduce the force needed by the user to hold the tool and improves user experience.

Referring to, the housingcomprises a main housingand a bottom housingthat are fixed together; the power scrubber further comprises a speed reducer, the speed reducercomprising an input shaft, an output shaft, and a planetary gear reduction construction, the planetary gear reduction construction being arranged between the input shaft and the output shaft, a rotary shaft of the electric motorbeing drivingly connected to the input shaft of the speed reducer, an upper end of the inner shaftbeing drivingly connected directly to the output shaftof the speed reducervia a coupling sleeve. The output shaftis set hollow axially. The inner shaftis rotatably supported inside the outer shaftby a first bearing set. The outer shaftis rotatably supported on the bottom housingby a second bearing set. An upper end of the inner shaftis provided with a gear sectionthat is located above the outer shaft. The drive assemblyfurther comprises a rack, a planetary gear, an upper planetary carrier, and a lower planetary carrier, the rackbeing fixed to a bottom portion of the speed reducer, a lower portion of the rackbeing provided with a ring gear, the upper planetary carrierbeing disposed at a bottom portion of the rack, the lower planetary carrierbeing located under the upper planetary carrier, the planetary gearbeing supported between the upper planetary carrierand the lower planetary carrierby a supporting shaft, an upper end of the supporting shaftbeing securely connected to the upper planetary carrier, a lower end of the supporting shaftbeing securely connected to the lower planetary carrier, an upper end of the outer shaftbeing securely connected to the upper planetary carrier. The ring gearon the rackis arranged vertically above the gear sectionon the inner shaft. Two or three planetary gearsare arranged circumferentially at even intervals, each planetary gearcomprising an upper toothed portionmeshing with the ring gearand a lower toothed portionmeshing with the gear section. When the electric motoris operating, power is outputted via the output shaftof the speed reducer, the output shaftdrives, via the coupling sleeve, the inner shaftto rotate synchronously, the rotating inner shaftdrives, via engagement between the gear sectionand the planetary gears, the upper planetary carrierand the lower planetary carrierto rotate, and the rotating lower planetary carrierdrives the outer shaftto rotate synchronously. Since the gear sectionand the planetary gearsmesh with each other, and they rotate in opposite directions, so that the inner shaftrotates in a direction opposite to the planetary carrier, and the inner shaftand the outer shaftalso rotate in opposite directions, whereby the electric motorcan actuate, via the drive assembly, the inner shaftand the outer shaftto rotate in opposite directions.

To facilitate removal and replacement of the disc brush, in this implementation, the outer disc bodyis removably thread-fitted to the lower end of the outer shaft; and the inner disc bodyis removably snap-fitted to the lower end of the inner shaft. The lower end of the outer shaftprojects downward from the bottom housingout of the housing, and a male threadis set on an outer peripheral surface of the lower end of the outer shaft. Referring to, a connecting holedisposed on top of the recessed cavityand communicating with the recessed cavityis set in the center of the outer disc body; a female threadis set on an inner wall of the connecting hole; the outer disc bodyis removably connected to the lower end of the outer shaftvia fitting between the female threadand the male thread. Referring to, the lower end of the inner shaftprojects downward out of the housing; a snap-on connectorprojecting out of the outer shaftis secured to the lower end of the inner shaft, and a plurality of snap-fitting blocksdistributed circumferentially at intervals are provided on an outer peripheral surface of the snap-on connector. Referring to, a fit-in holefitted with the snap-on connectoris set in the center of the inner disc body, a turnbucklecorresponding to the snap-fitting blockis arranged on an inner wall of the fit-in hole, and the inner disc bodyis removably connected to the lower end of the inner shaftvia fitting between the turnbuckleon the inner wall of the fit-in holeand the snap-fitting blockon the outer peripheral surface of the snap-on connector.

To ensure connection secureness of the outer disc body, a thread direction of the thread fitting is exemplarily set opposite the rotating direction of the outer shaft, so that the thread fitting becomes increasingly tighter while the outer shaftdrives the outer disc bodyto rotate, preventing the outer disc bodyfrom being loosened or released relative to the outer shaft. To ensure connection secureness of the inner disc body, the snap-fitting direction between the turnbuckleand the snap-fitting blockis exemplarily set opposite the rotating direction of the inner shaft, preventing the turnbuckleand the snap-fitting blockfrom being loosened or released while the inner disc bodyis rotating. Furthermore, the turnbucklecomprises an arcuate segmentextending circumferentially along the fit-in holeand a linear segmentextending axially along the fit-in hole, the arcuate segment, the linear segment, and the inner wall of the fit-in holebeing combined to form a fit-in recess. Referring to, a stop protrusionis provided at an upper surface of the snap-fitting blockand a lower surface of the arcuate segment, respectively; when the snap-fitting blockis snap-fittingly screwed in the fit-in recess, the stop protrusionon the upper surface of the snap-fitting blockand the stop protrusionon the lower surface of the arcuate segmentabut against each other in the circumferential direction of the fit-in hole, whereby the snap-fitting blockis circumferentially retained, which blocks the snap-fitting blockfitted in the fit-in recessfrom back movement, further improving structural stability of the inner disc body.

To control a radial size of the drive assembly, it is needed to set a rational speed ratio between the inner shaftand the outer shaft, based on which a rational speed ratio between the inner disc bodyand the outer disc bodyis set. In this implementation, the speed ratio between the inner disc bodyand the outer disc bodyranges from 1:1 to 9:1. Specifically, due to speed reduction transmission via the drive assembly, the revolution speed of the outer shaftis lower than that of the inner shaft; the speed ratio between the inner shaftand the outer shaftis about 4:1, so that the speed ratio between the inner disc bodyand the outer disc bodyis also 4:. It may be understood that, the speed ratio between the inner disc bodyand the outer disc bodymay also be set to other rational values such as 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, and 9:1.

Referring to, to facilitate the user to remove and replace the inner disc body, a plurality of finger groovesrecessed inwardly towards the center of the inner disc bodyare distributed at intervals on an outer peripheral surface of the inner disc body; the finger groovesallow for the user to effectively hold the inner disc body, whereby the user may effectively screw the inner disc body, causing the inner disc bodyto be snap-fitted with the inner shaftin place or to be disengaged therefrom.

Referring to, to enhance the effect of the disc brushscrubbing the to-be-cleaned object, a plurality of water discharge channelsdistributed circumferentially at even intervals may be provided on a top wall of the recessed cavity; a specific structure of the water discharge channelmay refer to the disclosure in CN216876248U, which would not be detailed here.

To use the power scrubber described herein, the outer disc bodyis first thread-fitted to the lower end of the outer shaft, and then the inner disc bodyis snap-fitted to the lower end of the inner shaft. The electric motoris started by activating the button on the housing, the running electric motoractuates, via the speed reducerand the drive assembly, the inner disc bodyand the outer disc bodyto rotate in opposite directions, and the inner disc bodyand outer disc bodyrotating in opposite directions drive the scrubbing bodyto scrub a to-be-cleaned object or surface. Since the softer bristle bundleat the underside of the inner disc bodyand the harder bristle bundleat the underside of the outer disc bodyhave different degrees of hardness, the user may use the harder bristle bundleor the softer bristle bundleto scrub local dirt according to scrubbing requirements.

In this implementation, the degrees of hardness of the scrubbing bodies made of a same material are differentiated based on the deformation degrees of the scrubbing bodies when the disc brushis subjected to a same stress. In a case that the disc brushis subjected to the same stress, the degree of deformation of the softer bristle bundleis greater than that of the harder bristle bundle.

It may be understood that, in this implementation, the softer bristle bundleand the harder bristle bundlemay be set with a same height, i.e., the lower end of the softer bristle bundleis set substantially flush with the lower end of the harder bristle bundle.

It may be understood that, the power scrubber according to this implementation may be powered by batteries, or may be powered by mains electricity via a wire.

It may be understood that, the power scrubber according to this implementation may have an appearance generally resembling a pistol structure, a linear structure, or an elongated rod structure.

It may be understood that, in this implementation, three or four types of bristle bundle structures with different degrees of hardness may be adopted at the underside of the disc brush, and the heights of these bristle bundles may increase or decrease sequentially from the inside to the outside; in this case, two or more types of bristle bundles with different degrees of hardness distributed sequentially from the inside to the outside may be set at the underside of the inner disc body, or, two or more types of bristle bundles with different degrees of hardness distributed sequentially from the inside to the outside may be set at the underside of the outer disc body.

It may be understood that, in this implementation, a scouring pad structure, a chenille fabric structure, or another structure suitable for scouring purposes may also be adopted at the underside of the disc brush. In a case of adopting the scouring pad structure, the scouring pad set at the undersides of the inner disc bodyand the outer disc bodymay be distributed in a manner of thicker inside and thinner outside or thinner inside and thicker outside; in a case of adopting the chenille fabric structure, the chenille fabric set at the undersides of the inner disc bodyand outer disc bodymay be distributed in a manner of thicker inside and thinner outside or thinner inside and thicker outside.

Referring to, in this implementation, the electric motoractuates, via the drive assembly, the inner disc bodyand the outer disc bodyto rotate in a same direction. Specifically, the electric motorcomprises a rotary shaftconfigured to output power, and the drive assemblyis disposed at a bottom portion of the electric motor. The drive assemblyfurther comprises a driving wheel, a first-stage planetary gear, a first-stage planetary carrier, a sun gear, a second-stage planetary gear, a second-stage planetary carrier, a ring gear cylinder, a coupling shaft, and a coupling cylinder. The driving wheelis sleeved over the rotary shaft. Two or three first-stage planetary gearsare set at even intervals along an outer periphery of the driving wheel, each first-stage planetary gearbeing disposed on the first-stage planetary carriervia a shaft and meshing with the driving wheel. The sun gearis disposed at a bottom portion of the first-stage planetary carrierand integrally formed with or fixedly connected to the first-stage planetary carrier. The second-stage planetary carrieris disposed at a bottom portion of the sun gear. Two or three second-stage planetary gearsare set at even intervals along an outer periphery of the sun gear, each second-stage planetary gearbeing disposed on the second-stage planetary carriervia a shaft and meshing with the sun gear. The first-stage planetary gears, the first-stage planetary carrier, the sun gear, the second-stage planetary gears, and the second-stage planetary carrierare arranged at an inner periphery of the ring gear cylinder; meanwhile, the first-stage planetary gearsand the second-stage planetary gearsboth mesh with the teeth on an inner wall of the ring gear cylinder. An upper end of the coupling shaftis fixedly connected to the driving wheel, a lower end of the coupling shaftis fixedly connected to an upper end of the inner shaftvia the coupling cylinder, and an upper end of the outer shaftis fixedly connected to the second-stage planetary carrier. When the electric motoris operating, the rotary shaftdrives the driving wheelto rotate synchronously. On one hand, the driving wheeldrives, via the coupling shaftand the coupling cylinder, the inner shaftto rotate; and on the other hand, the driving wheeldrives, via the first-stage planetary gears, the first-stage planetary carrier, the sun gear, the second-stage planetary gears, and the second-stage planetary carrier, the outer shaftto rotate. The meshing between the driving wheeland the first-stage planetary gearsand the meshing between the sun gearand the second-stage planetary gearsallow for the inner shaftand the outer shaftto rotate in a same direction, so that the inner disc bodyand the outer disc bodyrotate in the same direction. In this implementation, a supporting frameis arranged between the electric motorand the drive assembly. The electric motormay be fixed in the housingvia the supporting frame; and the first-stage planetary gearsare disposed at a bottom portion of the supporting frame.

The remaining structures of the second implementation are identical to those of the first implementation, which will not be detailed here.

In this implementation, the softer bristle bundle is set with a height larger than that of the harder bristle bundle, and diameter Dof the bristles forming the softer bristle bundle is smaller than diameter Dof the bristles forming the harder bristle bundle, i.e., D<D. For bristles made of a same material, bristles with a smaller diameter are softer, while bristles with a larger diameter are harder; in a case that the bristles of the softer bristle bundle and the bristles of the harder bristle bundle vary in height, thickness is a further variable that enlarges the difference between their hardnesses. As an optional solution to this implementation, the difference between Dand Dmay be set to a rational value such as 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, and 0.5 mm.