TW201700057A - Cleaning device having a cleaning roller that can be rotated about an axis of rotation - Google Patents

Abstract

The invention relates to a cleaning device (1), in particular a floor-cleaning device, comprising a cleaning roller (2) for processing a surface to be cleaned, which cleaning roller can be rotated about an axis of rotation (x), wherein the cleaning roller (2) is designed at least partially as a liquid-permeable hollow body (3) having an internal liquid space (4), wherein the hollow body (3) has openings (5) for liquid (6) to escape from the liquid space (4) to the surface (7) of the hollow body (3). In order to prevent an undesired escape or dripping of liquid, the cleaning roller (2) according to the invention is designed to block the escape of liquid (6) from the liquid space (4) below a minimum rotational speed (nmin) determined by a force balance between a capillary force (FK) and a centrifugal force (FZ) acting on the liquid and the escape of liquid (6) from the liquid space (4) is allowed once the minimum rotational speed (nmin) has been reached.

Description

Cleaning device having a cleaning roller rotatable about a rotating shaft

The present invention relates to a cleaning device, and more particularly to a floor cleaning device having a cleaning roller rotatable about a rotational axis for treating a surface to be cleaned, wherein the cleaning roller is at least partially constructed to have an internal liquid A liquid-permeable hollow body of the chamber, wherein the hollow body has an opening for discharging liquid from the liquid chamber to the surface of the hollow body.

In the prior art, cleaning devices of the above type are known. For example, the publication DE 20 2007 017 026 U1 discloses a floor cleaning device having a cleaning roller constructed as a wiping cylinder that is supplied with cleaning liquid from the inside. For this purpose, the cleaning roller has a liquid-permeable sleeve body. The sleeve body is provided with, for example, holes, slits, holes, and other forms of through holes to wet the cleaning cloth applied to the outside of the cleaning cylinder. The cleaning cloth and/or the sponge disposed between the sleeve body and the cleaning cloth as the case may have an absorbent capacity to continuously draw in liquid from the sleeve body through the opening. When the cleaning device moves on the surface to be cleaned, the liquid is transferred from the cleaning cloth or sponge to the surface to be cleaned by the contact pressure.

The disadvantage is that the liquid chamber of the self-cleaning drum continues to have liquid released to the surface of the hollow body, that is to say also to the cleaning cloth and/or the sponge. As a result, the liquid is released even when the cleaning roller is not used for the cleaning process but is, for example, only transported.

In view of the above, it is an object of the present invention to provide a cleaning apparatus in which liquid is delivered from a liquid chamber to a surface of a hollow body only under specific conditions, thereby avoiding undesired liquid spillage or dripping.

In order to achieve the object, the invention provides that the cleaning drum is constructed such that, when the minimum rotation speed (number of revolutions per unit time) is exceeded, the liquid chamber is prohibited from discharging the liquid, and the liquid chamber is allowed to discharge the liquid from the minimum rotation speed, and The minimum speed depends on the force balance between the capillary forces acting on its liquid and the centrifugal force.

First of all, the cleaning device can be constructed as a hand-held cleaning device, preferably a cleaning device that is manipulated through the shaft. Alternatively or additionally, the cleaning device can also be a floor care device. In particular, the floor care device or floor cleaning device can also be constructed as an automatic moving device. Automated moving devices can clean surfaces or spaces in a pre-programmed manner or by finding clean routes independently. The cleaning device can also be, for example, a window cleaning device. If it is constructed as an automatic moving device, the device can have or can be mated with an orientation device, for example in the form of a laser scanner. The cleaning device can also have a control device, in particular a microcomputer for storing and/or executing a control program.

According to the invention, whether or not liquid is released from the liquid chamber to the surface of the hollow body depends on the current rotational speed of the cleaning drum. Among them, it is based on the recognition that the liquid in the liquid chamber is subjected to capillary forces on the one hand, and on the other hand - when the cleaning drum rotates - is subjected to centrifugal force. The capillary force causes the liquid in the liquid chamber to rise under certain conditions into the opening of the hollow body constructed as a capillary and thus to the surface of the hollow body. This effect is caused by the surface tension of the liquid and the interfacial tension between the liquid and the inner wall of the opening. If the liquid wets the material of the surface, its liquid rises inside the capillary and forms a concave interface (meniscus). This property is attributed to adhesion. In contrast, there is also a "liquid-surface" combination of liquid non-wetting surfaces. In this case, the liquid forms a convex surface in the capillary. The capillary force depends on the surface tension of the liquid, the capillary diameter, and the contact angle between the liquid and the inner wall of the capillary. This point can be described by the formula F _K = σ × π × d × cos( θ ), where σ is the surface tension of water, d is the capillary diameter, and θ is the contact angle.

Further, when the cleaning roller is rotated about the rotating shaft, the centrifugal force also acts on the liquid located inside the liquid chamber. Wherein, the centrifugal force acts radially outward from the axis of rotation, that is, acts in the direction of the opening of the hollow body such that the liquid can be discharged from the liquid chamber to the surface under certain conditions. The centrifugal force here depends on the diameter d of the opening, the water level h inside the liquid chamber (when rotating), the density ρ of the liquid, the rotational speed v and the radius r of the center of gravity of the liquid. Assuming that only the liquid level below the opening is observed here, the centrifugal force is .

If the liquid wets the material of the hollow body, the capillary force and the centrifugal force point in the same direction, that is, radially outward. However, if the liquid does not wet the material of the hollow body, the capillary force is relatively resistant to the centrifugal force, so that the minimum rotational speed can be calculated according to the force balance between the capillary force and the centrifugal force, and the centrifugal force needs the minimum rotational speed to exceed the radial inward. The capillary force acts so that the liquid can reach the surface of the hollow body from the liquid chamber.

To this end, the equation F _K =F _Z is solved according to the velocity v. Resulting from

The obtained velocity v is associated with the rotational speed (unit time revolutions) n by the equation v = 2 × π × n × r .

Thereby, according to the surface tension of the liquid, the diameter of the opening, the contact angle, the radius of gravity of the liquid inside the liquid chamber, and the liquid inside the liquid chamber (when the cleaning roller rotates) The radius of gravity of the liquid inside the liquid chamber, the liquid level inside the liquid chamber (when the cleaning roller rotates), and the density of the liquid, the minimum rotational speed of the cleaning drum can be calculated for each configuration, and the liquid chamber can be self-sustained since the minimum rotational speed is reached. Drain the liquid. If the minimum rotational speed is not reached, that is, the cleaning drum rotates at a speed lower than the minimum rotational speed, the liquid cannot reach the surface of the hollow body from the liquid chamber. In this way, by adjusting the rotational speed of the cleaning drum, it is possible to selectively control when the liquid is discharged and when the liquid is not discharged. Thereby, the cleaning drum does not normally rotate during the simple transportation of the cleaning device, so that the liquid can be effectively prevented from being discharged. When the cleaning roller is used in a cleaning process requiring liquid use, it is rotated at a speed exceeding the minimum rotation speed so that the centrifugal force exceeds the capillary force, thereby releasing the liquid to the surface to be cleaned.

The invention proposes that the contact angle between the liquid and the inner wall of the opening is greater than 90° and the maximum is 270°. The angle of contact between the liquid and the inner wall of the opening is decisive for the liquid discharge from the liquid chamber. When the contact angle is greater than 90°, the cosine of the contact angle affecting the capillary force becomes negative. That is, the liquid does not rise into the opening, but is displaced in the opposite direction, so that the capillary force is opposed to the centrifugal force. The present invention utilizes this effect in selecting a combination of materials for the liquid and the hollow body to achieve a contact angle of greater than 90° and a maximum of 270°. In this case, the capillary force is correspondingly opposed to the centrifugal force of the liquid. When the speed of the cleaning roller is sufficient to cause the centrifugal force to exceed the capillary force, the liquid chamber discharges the liquid. In general, the liquid discharge can be adjusted by the choice of material, the rotational speed and the diameter of the opening. Therefore, pumps, valves, centrifugal force-dependent flaps or the like are not required.

The invention proposes that the liquid is water and the hollow body has a hydrophobic material, in particular polytetrafluoroethylene (PTFE). Among them, the polytetrafluoroethylene may be a coating of a hollow body, in particular, an open coating. The hydrophobicity of the hollow body makes the water larger than inside the opening The contact angle of 90° causes the capillary force to act in the direction of the liquid chamber and thus resists the centrifugal force. Thereby, the aforementioned force balance can be formed between the capillary force and the centrifugal force. In addition to PTFE, other hydrophobic materials such as wax or paraffin may also be used. In this case, the hollow body can consist entirely of a hydrophobic material or, at least in the interior of the liquid chamber, in particular inside the opening, with a coating of the hydrophobic material.

The invention proposes that the openings have a diameter of from 0.5 μm to 2 mm. This diameter is sufficiently small to prevent liquids located inside the liquid chamber from flowing out of the liquid chamber through the openings only by gravity. Furthermore, the opening having the above diameter has a capillary effect of sufficient strength, i.e., the liquid rises to a sufficiently large height inside the opening to achieve the working principle of the present invention. The openings may advantageously be capillary tubes formed in an open-celled manner in the material of the hollow body. As an alternative, it is also expedient to use a hollow body composed of a material comprising a capillary. However, in the latter case, the present invention is subject to the premise that the diameters of the openings are substantially equal or have a clearly defined minimum dimension to enable determination of liquid discharge for the liquid chamber. Common minimum speed.

The invention further provides that the hollow body has openings of different sizes, the openings having mutually different diameters, wherein the opening having the first diameter corresponds to the first minimum rotational speed, and wherein the opening having the second diameter corresponds to the first Two minimum speeds. According to this solution, two rotational speeds can be defined for the cleaning drum, from which the respective openings allow liquid to escape. In this way, for example, the opening having the second larger diameter initially (even in the case of reaching the first minimum rotational speed) prohibits the liquid from being discharged, and only allows the liquid to be discharged when the second minimum rotational speed is reached. Thereby, two or more sets of openings having different diameters can be provided, which allow only a certain degree of wetting of the cleaning roller depending on the rotational speed, and allow more water to be discharged only when the rotational speed is increased.

The present invention provides that the cleaning device is a dry cleaning device, wherein the cleaning roller is configured to prohibit the liquid chamber of the hollow body from discharging liquid at a first rotation speed corresponding to the surface treatment performed by the cleaning roller, and The liquid chamber is allowed to drain the liquid at a second, higher rotational speed corresponding to the self-cleaning of the cleaning drum. Thus, the invention is not limited to wet cleaning devices. In particular, the invention can also be applied particularly advantageously to dry cleaning devices. Here, the cleaning device is constructed such that the rotational speed used to treat the surface to be cleaned in a conventional manner is lower than the minimum rotational speed required to discharge the liquid. Thereby, dry cleaning can be carried out by the cleaning roller at the first rotational speed without the hollow body undesirably discharging the liquid. Only when the minimum speed of the cleaning drum is reached, the liquid chamber releases liquid. This minimum or higher speed may be set when the cleaning drum requires self-cleaning, for example to cause the cleaning drum to rotate. Wherein, the cleaning roller is sufficiently washed with the liquid to cause the dirt adhering to the surface of the cleaning roller to fall off, and after the subsequent drying, the cleaning roller can be reused for the dry cleaning process. Therefore, the present invention can also be applied to a dry cleaning device having a cleaning drum self-cleaning device, and the effect is outstanding.

The present invention further provides that the cleaning device is a wet cleaning device, wherein the cleaning roller is configured to allow the liquid chamber of the hollow body to discharge first at a first rotational speed corresponding to the surface treatment performed by the cleaning roller. The liquid is metered and, in a particularly high second rotational speed corresponding to the self-cleaning of the cleaning cylinder, the liquid chamber is allowed to expel a second amount of liquid. Therein, the wet cleaning device has two different speed steps for cleaning the rotation of the drum. During the face treatment by the cleaning roller, the cleaning roller rotates at the first rotational speed, so that the liquid chamber releases the amount of liquid corresponding to the current force balance. The invention can be provided with a second speed stage independent of the wet processing of the surface, which is used for self-cleaning of the cleaning drum and is provided with a higher second rotation speed, at which the liquid chamber can discharge more Liquid to fully flush the cleaning roller. In addition, within the following The volume is also applicable to the present embodiment: when the cleaning device is simply transported, the cleaning roller does not rotate, so that it is impossible for the liquid chamber to discharge the liquid at this time. Thereby, undesired liquid dripping is prevented with an optimum effect.

The invention proposes that the minimum rotational speed of the cleaning drum is at least 150 revolutions per minute to 3000 revolutions per minute. Among them, the specified minimum rotational speed of 150 revolutions per minute is much higher than the accidental rotation of the cleaning roller during the transportation of the cleaning device. Similarly, this minimum rotational speed also exceeds the rotational speed of the cleaning drum when the cleaning device is simply moved on the surface to be cleaned. Specifically, the specified rotational speed range of 150 rpm to 3000 rpm is equivalent to the normal rotational speed of the cleaning roller when performing the process to clean the surface or self-cleaning to remove adhering dirt. Among them, the minimum rotational speed required for the hollow body to discharge the liquid depends on the aforementioned parameters affecting the centrifugal force and the capillary force.

Finally, it is proposed that the hollow system is covered by the sponge. Additionally or alternatively, it may be provided that the hollow body and/or the sponge system is covered by a cleaning cloth, in particular a microfiber cloth. Wherein, the surface of the cleaning roller is covered with a sponge body and/or a cleaning cloth. The cleaning cloth may be, for example, a fabric cleaning cloth, and dirt that has fallen off from the surface to be cleaned is fixed in the fabric cleaning cloth. In this case, it is extremely advantageous to construct the cleaning cloth as a microfiber cloth. This is particularly advantageous for removing dirt from the surface to be cleaned. The cleaning cloth and the sponge are advantageously absorbent so that a certain amount of liquid can be stored. As an alternative to the cleaning cloth, or alternatively between the hollow body and the cleaning cloth, a sponge can be provided. The sponge is mainly used as a temporary reservoir for liquids. The sponge absorbs the liquid discharged from the opening of the hollow body and releases the liquid to the cleaning cloth or the surface to be cleaned.

The invention is explained in detail below in conjunction with the examples.

1‧‧‧ cleaning device

2‧‧‧Clean roller

3‧‧‧ hollow body

4‧‧‧Liquid chamber

5‧‧‧ openings

6‧‧‧Liquid

7‧‧‧(hollow body) surface

8‧‧‧ (opening) inner wall

9‧‧‧cavernous body

10‧‧‧ Cleaning cloth

11‧‧‧Additional devices

12‧‧‧ Filling port

D‧‧‧ (opening) diameter

F _K ‧‧‧Capillary force

F _Z ‧‧‧ centrifugal force

H‧‧‧(liquid/liquid ring) water level/level

n‧‧‧Speed

n _min ‧‧‧minimum speed

R‧‧‧(cleaning device) moving direction

R‧‧‧ (liquid/liquid ring) center of gravity radius

V‧‧‧speed

x‧‧‧Rotary axis

Θ‧‧‧contact angle

Ρ‧‧‧(liquid) density

Σ‧‧‧(liquid) surface tension

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic perspective view of a cleaning device of the present invention; Figure 2 is a schematic perspective view of a cleaning roller of the present invention; Figure 3 is a cross-sectional view of a cleaning roller including parameter definitions; and Figure 4 is a cross-sectional view of the cleaning roller.

First, a cleaning device 1 is shown and described in connection with Figure 1 in the form of a wet cleaning device for wet cleaning the surface to be cleaned. The cleaning device 1 has an additional device 11 that contacts the surface to be cleaned during the cleaning process. The attachment device 11 here has two cleaning drums 2 that can be loaded with liquid 6 from the inside. To this end, the attachment device 11 has a reservoir (not shown) that is permeable to the liquid 6 through the filler port 12. The liquid 6 reaches the cleaning drum 2 from the reservoir through a liquid conduit (not shown). The cleaning device 1 is supported by the two cleaning rollers 2 to be supported on the surface to be cleaned. The cleaning roller 2 extends transversely to the normal travel direction r of the cleaning device 1, which is caused by the normal working movement of the user of the cleaning device 1, that is, generally alternating motion before and after, and is slightly avoided as appropriate. A clean path. The extent of the cleaning roller 2 extends almost over the entire width of the cleaning device 1 transverse to the direction r of travel. Corresponding to the arrangement shown in the drawing, when the cleaning device 1 is moved in the traveling direction r, a cleaning roller 2 is provided on the attachment device 11 in front and rear. The cleaning roller 2 can be driven by an electric motor (not shown), that is, rotatable about the axis of rotation x. During the conventional migration of the cleaning device 1, the cleaning roller 2 is not actively driven without treating the surface to be cleaned. Specifically, the cleaning drum 2 is passively rotated based only on the frictional connection with the face to be cleaned. The cleaning roller 2 is actively rotated by the motor during cleaning of the face by the cleaning roller 2 and/or during self-cleaning of the cleaning roller 2. During the cleaning process, a wiping edge is formed along the line of contact between the cleaning roller 2 and the surface to be cleaned. The wiping edge is transmitted through the temporary wiping edge relative to The movement of the face, and the task of cleaning the face, to remove dirt. The cleaning roller 2 is supplied with a liquid 6 to effect wet cleaning. This liquid is advantageously water, optionally with a cleaning agent. This liquid 6 is initially stored in the reservoir of the attachment device 11. Next, the cleaning drum 2 is supplied with the liquid 6 through the reservoir. For this purpose, each cleaning drum 2 has a hose line in the axial end region of the cleaning drum 2. Therefore, the free end region of the hose duct extends parallel to the rotational axis x of the cleaning drum 2.

Figure 2 shows a detailed view of the cleaning roller 2. Therein, the different cladding layers of the cleaning drum 2 are shown in an exploded view. The cleaning drum 2 is basically constructed as a cylindrical hollow body 3 with an end face closed, wherein the end face closure is not shown for a more intuitive graphical effect. The hollow body 3 is composed of a hard plastic material and is here coated with a hydrophobic material, ie PTFE. The hollow body 3 is of a liquid permeable design, in particular: the hollow body 3 has a plurality of openings 5 which are distributed over the surface 7 and which are constructed as capillaries. The interior of the hollow body 3 forms a cylindrical chamber 4 which is also cylindrical in shape for accommodating the liquid 6. The liquid 6 can pass from the liquid chamber 4 to the surface 7 of the hollow body 3 through the opening 5 under certain conditions. The opening 5 has an inner wall 8 which is likewise coated with a hydrophobic material. The hollow body 3 is surrounded by a sponge 9 which is arranged on the hollow body in a rotationally fixed manner. The sponge 9 has a porous design and has the ability to temporarily store the liquid 6. The sponge 9 is covered with a cleaning cloth 10, here a microfiber cloth. The cleaning cloth 10, the sponge body 9 and the hollow body 3 are connected to each other in a rotationally fixed manner and are rotatable together about a rotation axis x. The liquid chamber 4 of the hollow body 3 serves as a reservoir for the liquid 6. The reservoir is replenished with liquid through the aforementioned storage tank and hose line. After the sponge 9 and/or the cleaning cloth 10 are loaded with the liquid 6, the two are released to the surface to be cleaned under the pressure generated by the movement of the cleaning device 1 on the surface to be cleaned. Here, the liquid 6 is discharged in the region of the wiping edge. Among them, the liquid 6 is extruded into the sponge 9 and/or the cleaning cloth 10, and is applied to the surface to be cleaned through the cleaning cloth 10. When cleaning the drum 2 Further, when rotating in the traveling direction r of the cleaning device 1, the dirt is peeled off from the surface to be cleaned and transferred to the cleaning cloth 10.

The liquid 6 is discharged from the liquid chamber 4 to the surface 7 of the hollow body 3, which depends on the capillary force F _K and the centrifugal force F _Z generated by the rotation of the cleaning drum 2. However, when the minimum rotational speed n _{min of the} cleaning drum 2 is exceeded, the centrifugal force F _Z exceeds the capillary force F _K . Thereby, the capillary force F _K which is oriented radially inward based on the hydrophobicity of the inner wall 8 of the opening 5 can be overcome.

Figure 3 shows a schematic cross-sectional view of the cleaning drum 2, as well as the parameters required to determine the capillary force F _K and the centrifugal force F _Z . The cleaning drum 2 is shown with a hollow body 3. The hollow body 3 has a surface 7 comprising a plurality of openings 5 which enclose a liquid chamber 4 for accommodating the liquid 6. For the sake of simplicity, only a single opening 5 is shown in the drawings. Of course, the cleaning roller 2 can have a plurality of regularly or irregularly distributed openings 5 through which the liquid 6 can pass from the liquid chamber 4 to the surface 7 of the hollow body 3. The cleaning drum 2 shown here is not provided with a sponge body 9 and a cleaning cloth 10. This is primarily intended to achieve a more intuitive graphical effect and not to limit the embodiments. The opening 5 has an inner wall 8 coated with a hydrophobic material. In the idealized state shown in the drawings, the liquid 6 located inside the liquid chamber 4 is transmitted through the rotation of the cleaning drum 2 about the rotation axis x to form a regular liquid ring. This ring has a center of gravity radius r starting from the axis of rotation x and a water level h corresponding to the width of the liquid ring. The opening 5 has a diameter d. Since the hydrophobic coating 3 of the hollow body, in particular, due to the inner wall of the opening 5 of the hydrophobic coating 8, the direction of capillary force F _K is radially inwardly. Therefore, the capillary force is opposed to the radially outwardly directed centrifugal force F _Z generated by the rotation of the cleaning drum 2.

Figure 4 shows an embodiment of a cleaning drum 2 having a plurality of openings 5, the inner walls 8 of which are coated with PTFE and are hydrophobic. Due to its hydrophobic coating, liquid 6 (here water) cannot wet the inner wall 8 of the opening 5. Thereby, the inside of the opening 5 forms a convex liquid surface. As such, within the opening 5, the contact angle θ between the inner wall 8 and the liquid 6 is greater than 90°. Under this condition, the capillary force F _K defined as F _K = σ × π × d × cos( θ ) becomes negative, so that the capillary force is proportional to the centrifugal force F _Z oriented radially outward from the axis of rotation x confrontation. among them .

Specifically, the rotational speed v and the rotational speed (unit number of revolutions) n of the cleaning drum 2 around the rotational axis x such that the capillary force F _K and the centrifugal force F _{Z are} balanced depend on several parameters, namely: surface tension of the liquid: σ The diameter of the opening 5: d, the radius of gravity of the liquid 6: r, the contact angle between the liquid 6 and the inner wall 8: θ, the liquid level: h, the density of the liquid 6: ρ.

In the illustrated embodiment, the liquid 6 is water and the inner wall 8 is coated with PTFE, resulting in the following values:

d =1×10 ^-3 m

r = 15 × 10 ^-3 m

θ =110°

h =1×10 ^-2 m

By using this numerical value, the velocity v is calculated, and after rounding, , approximately equivalent to n = 423.3 rev / min.

The minimum rotational speed n _min is the rotational speed n that must be exceeded when the liquid 6 is discharged from the liquid chamber 4 through the opening 5 and reaches the surface 7 . The liquid is optionally placed on the surface 7 by the sponge 9 and/or the cleaning cloth 10 . absorb.

If the cleaning device 1 does not touch the surface to be cleaned, for example, but is transported, for example, the rotational speed n of the cleaning drum 2 is zero, so that the minimum rotational speed n _min is not exceeded and the liquid chamber 4 does not discharge the liquid 6. On the other hand, when the cleaning drum 2 is rotated at a rotation speed n of, for example, 424 revolutions per minute for realizing the cleaning process, the liquid 6 can be discharged from the liquid chamber 4 through the opening 5 and used for the cleaning process. Depending on the desired embodiment of the cleaning device 1, the hollow body 3 can also have openings 5 of different sizes, which openings correspond to different minimum rotational speeds _nmin . For example, a first minimum rotational speed n _min may be set to provide a liquid 6 for the cleaning process of the surface to be cleaned, and a second minimum rotational speed _nmin is provided to provide liquid 6 for the self-cleaning process of the cleaning drum 2, cleaning At this second minimum speed, the drum 2 rotates faster than during the surface treatment.

2‧‧‧Clean roller

3‧‧‧ hollow body

4‧‧‧Liquid chamber

5‧‧‧ openings

6‧‧‧Liquid

8‧‧‧ (opening) inner wall

F _K ‧‧‧Capillary force

F _Z ‧‧‧ centrifugal force

Claims (10)

A cleaning device, in particular a floor cleaning device, having a cleaning roller (2) rotatable about a rotation axis (x) for treating a surface to be cleaned, wherein the cleaning cylinder (2) is at least partially constructed It is a liquid-permeable hollow body (3) having an inner liquid chamber (4), wherein the hollow body (3) has a means for discharging the liquid (6) from the liquid chamber (4) to the hollow body (3) The opening (5) of the surface (7) is characterized in that the cleaning roller (2) is constructed such that, when the minimum rotation speed (n _min ) is lower, the liquid chamber (4) is prohibited from discharging the liquid (6), And, since the minimum rotational speed (n _min ) is reached, the liquid chamber (4) is allowed to discharge the liquid (6), and the minimum rotational speed thereof depends on the capillary force (F _K ) and the centrifugal force (F _Z ) acting on the liquid thereof. Balance between forces. The cleaning device of claim 1, wherein the contact angle (θ) between the liquid (6) and the inner wall (8) of the opening (5) is greater than 90° and at most 270°. A cleaning device according to claim 1 or 2, wherein the liquid (6) is water, and the hollow body (3) has a hydrophobic material, in particular, polytetrafluoroethylene (PTFE). A cleaning device according to any of the preceding claims, wherein the openings (5) have a diameter (d) of from 0.5 microns to 2 mm. A cleaning device according to any of the preceding claims, wherein the hollow body (3) has openings (5) of different sizes, the openings having mutually different diameters (d), and wherein having a first diameter ( The opening (5) of d) corresponds to the first minimum rotational speed (n _min ), and wherein the opening (5) having the second diameter (d) corresponds to the second minimum rotational speed (n _min ). A cleaning device according to any one of the preceding claims, wherein the cleaning device (1) is a dry cleaning device, and wherein the cleaning roller (2) is constructed to correspond to the cleaning roller (2) At the first rotational speed (n) of the surface treatment performed, the liquid chamber (4) of the hollow body (3) is prohibited from discharging the liquid (6), and in the self-cleaning corresponding to the cleaning drum (2) At the second, higher rotational speed (n), the liquid chamber (4) is allowed to drain the liquid (6). A cleaning device according to any one of the preceding claims, wherein the cleaning device (1) is a wet cleaning device, and wherein the cleaning roller (2) is constructed to correspond to the cleaning roller (2) At a first rotational speed (n) of the surface treatment performed, the liquid chamber (4) of the hollow body (3) is allowed to discharge a first amount of liquid (6) and, corresponding to the cleaning drum (2) The self-cleaning, in particular the higher second rotational speed (n), allows the liquid chamber (4) to discharge a second amount of liquid (6). A cleaning device according to any of the preceding claims, wherein the cleaning drum (2) has a minimum rotational speed (n _min ) of at least 150 rpm to 3000 rpm. A cleaning device according to any of the preceding claims, wherein the hollow body (3) is covered by a sponge (9). A cleaning device according to any of the preceding claims, wherein the hollow body (3) and/or the sponge (9) are covered by a cleaning cloth (10), and the cleaning cloth (10) is in particular fine fiber cloth.