Abstract:
The invention relates to a floor cleaning appliance comprising a housing, on the underside of which is arranged at least one drivable cleaning tool for removing dirt from a surface to be cleaned, and further comprising a suction unit for vacuuming-off the dirt and a dirt container for receiving the vacuumed-off dirt. In order to so develop such a floor cleaning appliance that it is easier to service, it is proposed in accordance with the invention that the housing comprise a dirt container receptacle in which the dirt container is releasably positionable, and, in addition, at least one functional device receptacle for at least one functional device, the at least one functional device or a cover of the at least one functional device being freely accessible after removal of the dirt container from the dirt container receptacle.

Description:
[0001]    This application is a continuation of international application number PCT/EP2009/000415 filed on Jan. 23, 2009 and claims the benefit of German Patent Application No. 10 2008 008 066.7 filed on Feb. 1, 2008. 
         [0002]    The present disclosure relates to the subject matter disclosed in international application number PCT/EP2009/000415 of Jan. 23, 2009 and German application number 10 2008 008 066.7 of Feb. 1, 2008, which are incorporated herein by reference in their entirety and for all purposes. 
     
    
     BACKGROUND OF THE INVENTION 
       [0003]    The invention relates to a floor cleaning appliance comprising a housing, on the underside of which is arranged at least one drivable cleaning tool for removing dirt from a surface to be cleaned, and further comprising a suction unit for vacuuming-off the dirt and a dirt container for receiving the vacuumed-off dirt. 
         [0004]    The object of the present invention is to so develop such a floor cleaning appliance that it is easier to service. 
       SUMMARY OF THE INVENTION 
       [0005]    This object is accomplished, in accordance with invention, with a floor cleaning appliance of the kind mentioned at the outset in that the housing comprises a dirt container receptacle in which the dirt container is releasably positionable, and, in addition, at least one functional device receptacle for at least one functional device, the at least one functional device or a cover of the at least one functional device being freely accessible after removal of the dirt container from the dirt container receptacle. 
         [0006]    Owing to the dirt container being detachably removable from the dirt container receptacle, it is possible to transport the dirt container, for example, for emptying purposes, to a place remote from the floor cleaning appliance, so that there is no necessity to transport the entire floor cleaning appliance. The dirt container is preferably adapted to be arranged without the need for tools in the dirt container receptacle and to be removed from the dirt container receptacle without the need for tools. 
         [0007]    The floor cleaning appliance according to the invention also comprises at least one functional device receptacle for at least one functional device of the floor cleaning appliance. After detachment of the dirt container from the dirt container receptacle, the at least one functional device or a cover thereof, where provided, is freely accessible. This enables, for example, a user of the floor cleaning appliance to reach a functional device of the floor cleaning appliance in a convenient way, in order, for example, to carry out a visual check and, if required, exchange the functional device. To do so, he only has to remove the dirt, container from the dirt container receptacle. Therefore, even a technical layman can easily perform simple maintenance and/or repair work. Functional devices which ought not to be manipulated by the user but should be accessible to a service technician may be covered by a cover. The cover is accessible after removal of the dirt container from the dirt container receptacle. A service technician can remove the cover using a suitable tool and thereby gains access to functional devices which may, for example, have an electric voltage applied to them. These functional devices can then also be easily tested and, where required, exchanged. The floor cleaning appliance is therefore distinguished by a high level of service amenability. 
         [0008]    It is expedient for the at least one functional device receptacle and/or the dirt container receptacle to be constructed in the form of a depression formed on the housing. The configuration as depression, which may, for example, be trough-shaped or groove-shaped, allows the at least one functional device receptacle and/or the dirt container receptacle to be formed in a constructionally simple manner. Also, the accessibility of the respective functional device is thereby further simplified. 
         [0009]    Preferably, the at least one functional device receptacle and/or the dirt container receptacle is formed on the upper side of the housing. This makes it possible to arrange the dirt container and the at least one functional device at the upper side of the housing. The dirt container and/or the at least one functional device are then conveniently accessible to the user. 
         [0010]    It is advantageous for a functional device receptacle to accommodate a liquid pump for conveying a cleaning liquid. The liquid pump constitutes a functional device. A cleaning liquid can be conveyed with it, for example, in order to act upon the surface to be cleaned with the cleaning liquid. Typically, the cleaning liquid is water to which a chemical cleaning agent may be added to increase the cleaning effect. The liquid pump is electrically connected to an electric power supply. It is, therefore, advantageous for it to be covered by a cover to protect it from being touched. The cover is accessible by removing the dirt container from the dirt container receptacle. Therefore, if required, the liquid pump can be easily exchanged by a service technician. 
         [0011]    Preferably, at least one functional device receptacle accommodates at least one liquid pipeline. The liquid pipeline is a functional device by means of which the cleaning liquid can be conveyed. The liquid pipeline is expediently accommodated in a groove-shaped depression which forms a functional device receptacle. The liquid pipeline is readily accessible to a user of the floor cleaning appliance by removing the dirt container from the dirt container receptacle. Preferably, the liquid pipeline is transparent; for example, it may be in the form of a transparent hose. This enables a user to make a simple visual check, i.e., he can, for example, check whether the pipeline is clogged or leaking. If required, he can exchange the pipeline without having to call in a service technician to do this. 
         [0012]    It is expedient for the liquid pump to be connectable to at least one liquid pipeline and/or for two or more liquid pipelines to be connectable to one another by plug-in connections. This increases the level of service amenability of the floor cleaning appliance as a user is able to easily separate a liquid pipeline from the liquid pump and/or two liquid pipelines from each other, for example, for maintenance and/or repair. 
         [0013]    Advantageously, at least one functional device receptacle accommodates at least one electric device of the floor cleaning appliance, and the device is preferably covered by a cover to protect it from being touched. The electric device also constitutes a functional device. It may, for example, be a controlling and/or regulating device or an electric switching and/or connecting device or the like. 
         [0014]    Preferably, at least one functional device receptacle accommodates at least one electric line. The electric line, which, for example, is connectable to a device of the aforementioned kind, is also a functional device of the floor cleaning appliance. 
         [0015]    To further increase the level of service amenability of the floor cleaning appliance, it is expedient for the electric device to be connectable to at least one electric line and/or for two or more electric lines to be connectable to one another by plug-in connections. In this way, it is possible to easily separate the electric line from the electric device and/or two electric lines from each other. 
         [0016]    Furthermore, it may be provided that the suction unit is connectable by plug-in connections to one or more electric lines. 
         [0017]    Preferably, the suction unit is arranged at or on the upper side of the housing, and the floor cleaning appliance has a cover for covering the suction unit, the cover being releasably connectable to the housing and being freely accessible after removal of the dirt container from the dirt container receptacle. By arranging the suction unit at or on the upper side of the housing, the cover can be conveniently reached after removal of the dirt container from the dirt container receptacle, which, for example, facilitates maintenance and/or repair of the suction unit for a service technician. To expose the suction unit, the cover, which is releasably connectable to the housing, can be separated from the housing. It may be provided that the suction unit is held on the cover, so that when the cover is released from the housing, the suction unit is simultaneously released from the housing. It is, however, also possible for the suction unit to be acted upon with force by the cover and thereby fixed relative to it. 
         [0018]    Preferably, the cover comprises a lower cover part by means of which the cover is releasably connectable to the housing, and an upper cover part which is releasably connectable to the lower cover part. The suction unit can be exposed by releasing the lower cover part from the housing or, if it is held on the cover, it can be separated together with the cover from the housing. A space in which the suction unit is arranged becomes accessible by the upper cover part being removed from the lower cover part. This may be of advantage, if, for example, for maintenance and/or repair of the suction unit, only an area thereof that can be reached by releasing the upper cover part from the lower cover part need be accessed. 
         [0019]    Advantageously, the housing comprises at least one through-opening for passage of an electric line and/or a liquid pipeline therethrough as this makes it possible to impart a compact design to the floor cleaning appliance. For example, it may be provided that a cleaning liquid is conducted by a liquid pipeline passing through a through-opening to the underside of the housing in order to act upon the surface to be cleaned. 
         [0020]    Preferably, the housing comprises at least one through-opening through which a medium that is drawn in or discharged by the suction unit is drawn in or discharged. The housing can thereby form, for example, a section of an intake duct arranged upstream of the suction unit or of a discharge duct arranged downstream of the suction unit. In the case of the intake duct, it may, for example, be provided that the through-opening forms an interface between a dirt pickup device for picking up the dislodged dirt from the surface to be cleaned and a suction pipe through which the dirt can pass into the interior of the dirt container. In the case of the discharge duct, it is, for example, possible to conduct the exhaust air of the suction unit in a specific way through the housing to a certain area. 
         [0021]    The service amenability of the floor cleaning appliance can be further improved by the above-described through-openings of the housing and/or seals and/or filters adapted to be arranged thereon also being freely accessible after removal of the dirt container from the dirt container receptacle. 
         [0022]    The floor cleaning appliance has a technically simple construction when the housing comprises an upper housing part and a lower housing part, the dirt container receptacle and/or the at least one functional device receptacle being arranged at the upper housing part, and the lower housing part forming at least one cleaning compartment in which at least one cleaning tool is arranged. 
         [0023]    A compact design of the floor cleaning appliance can be achieved when a drive compartment is formed between the upper housing part and the lower housing part for accommodating a drive device by means of which the at least one cleaning tool is drivable. 
         [0024]    In this case, it has proven advantageous for the floor cleaning appliance to comprise two cleaning tools constructed as roller-type brushes, which are mounted for rotation in two cleaning compartments on the housing, and for the drive device to be arranged in the drive compartment between the roller-type brushes and to have a drive axis extending parallel to the axes of rotation of the roller-type brushes. Dirt can be removed from the surface to be cleaned by the roller-type brushes. The arrangement of the drive device in the drive compartment between the roller-type brushes allows a compact design of the housing of the floor cleaning appliance. Owing to the coaxial alignment of the drive device and the roller-type brushes, a driving force can be transmitted in a technically simple way from the drive device onto the roller-type brushes. 
         [0025]    The floor cleaning appliance is expediently constructed as a scrubber vacuum. 
         [0026]    The floor cleaning appliance preferably comprises an exhaust air guiding device for directing an exhaust air flow of the exhaust air of the suction unit onto at least one cleaning tool. Owing to the exhaust air flow being directed onto the cleaning tool, the exhaust air is captured and spatially distributed by the cleaning tool as a result of its motion. It has been found that noise generation due to the typically high flow velocity of the exhaust air of the suction unit can thereby be effectively reduced. The high flow velocity of the exhaust air is a consequence of the need to equip the suction unit with high suction power in order to be able to effectively vacuum-off the dislodged dirt. 
         [0027]    It is advantageous for the exhaust air flow to be directed by the exhaust air guiding device onto the side of the at least one cleaning tool that faces away from the surface to be cleaned. It has been found that the exhaust air flow can in this way be particularly effectively captured and spatially distributed by the cleaning tool, with the result that the noise generation can be further reduced. Furthermore, it is thereby possible to prevent dirt located on the surface to be cleaned from being spatially distributed in an undesired manner by the exhaust air flow. 
         [0028]    The floor cleaning appliance preferably comprises an accommodating compartment for the suction unit and at least one cleaning compartment formed on the housing for accommodating at least one cleaning tool, the exhaust air guiding device forming at least one exhaust air duct by way of which the accommodating compartment is in flow connection with at least one cleaning compartment. The exhaust air flow can be reliably directed onto the cleaning tool by the exhaust air duct, so that an effective reduction in noise is achievable. 
         [0029]    It may be provided that more than one cleaning tool is arranged in a cleaning compartment, with the exhaust air flow being directable onto only one or onto several cleaning tools, in particular, onto each cleaning tool. If the housing forms more than one cleaning compartment, it is then possible for several cleaning compartments, in particular, each of the cleaning compartments, to be in flow connection with the accommodating compartment. 
         [0030]    Furthermore, it may be provided that a separate exhaust air duct formed, for example, by a hose is used in the floor cleaning appliance, with, for example, the hose ends extending into the accommodating compartment and the cleaning compartment in order to establish the flow connection. 
         [0031]    A compact design can be imparted to the floor cleaning appliance when the housing delimits the exhaust air duct, at least in sections thereof. 
         [0032]    The compact design described above can be achieved in a constructionally simple way when a section of the housing that delimits the exhaust air duct is formed as through-opening of the housing. 
         [0033]    It is advantageous for the housing to comprise a wall delimiting the at least one cleaning compartment and forming at least one outlet opening of an exhaust air duct. This allows the exhaust air flow to be reliably directed onto a cleaning tool arranged in the cleaning compartment. 
         [0034]    Preferably, the floor cleaning appliance comprises a cover which is releasably connectable to the housing and has a first section delimiting at least one exhaust air duct, at least in sections thereof. The exhaust air duct can be opened, at least in sections thereof, by releasing the cover from the housing. This enables objects which are blocking the exhaust air duct to be easily removed from the exhaust air duct. This embodiment therefore increases the service amenability of the floor cleaning appliance. 
         [0035]    It is advantageous for the cover to have a second section, the accommodating compartment for the suction unit being formed between the second section and the housing. The cover can therefore cover the suction unit arranged in the accommodating compartment and delimit at least one exhaust air duct, at least in sections thereof. 
         [0036]    The following description of a preferred embodiment of the invention serves in conjunction with the drawings for a more detailed explanation of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0037]      FIG. 1  shows a diagrammatic side view of a floor cleaning appliance according to the invention with a housing on which a dirty water tank and a fresh water tank are placed; 
           [0038]      FIG. 2  shows a plan view of the housing of the floor cleaning appliance; 
           [0039]      FIG. 3  shows a sectional view taken along line  3 - 3  in  FIG. 2 , including the dirty water tank and the fresh water tank of the floor cleaning appliance; 
           [0040]      FIG. 4  shows a sectional view taken along line  4 - 4  in  FIG. 2 , including the dirty water tank and the fresh water tank of the floor cleaning appliance; and 
           [0041]      FIG. 5  shows a perspective view of an upper housing part, a cover element, a suction unit and a two-part cover for the suction unit of the floor cleaning appliance from  FIG. 1  in an exploded representation. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0042]    The drawings show diagrammatically a preferred embodiment of a floor cleaning appliance according to the invention which, in the present case, is constructed as a scrubber vacuum  10 . It comprises a housing  12 , on the underside  14  of which two cleaning tools in the form of two roller-type brushes  16  and  18  are mounted for rotation about two axes of rotation  20  and  22 , respectively. The axes of rotation  20  and  22  extend parallel to a surface to be cleaned and are aligned perpendicularly to a cleaning direction of the scrubber vacuum  10 , which is denoted by reference numeral  24  in  FIG. 1 . 
         [0043]    A push bar  28  mounted on the upper side  26  of the housing  12  for pivotal movement about a pivot axis extending parallel to the axes of rotation  20  and  22  serves to move the scrubber vacuum  10  forwards or backwards along the cleaning direction  24 . The push bar  28  is in operative connection, in a manner which is known and therefore not explained, with a pivot mechanism, not shown, by means of which supporting rollers  30 ,  31 ,  32  and  33  arranged on the underside  14  of the housing  12  may be raised and lowered in a vertical direction. When the push bar  28  is pivoted out of the vertical, the supporting rollers  30 ,  31 ,  32  and  33  may be raised relative to the roller-type brushes  16 . and  18 , so that the roller-type brushes  16  and  18  contact the surface to be cleaned. 
         [0044]    There is placed on the upper side  26  of the housing  12  a dirt container  34  in the form of a dirty water tank  36 , on which, in turn, a fresh water tank  38  is placed. The dirty water tank  36  and the fresh water tank  38  will be explained below. 
         [0045]    The housing  12  comprises a lower housing part  40  and an upper housing part  42 . The lower housing part  40  forms two cleaning compartments  44  and  46  in which the roller-type brushes  16  and  18 , respectively, are arranged ( FIGS. 3 and 4 ). The cleaning compartments  44  and  46  are delimited at the sides and at the top by dome-shaped delimiting walls  48  and  50 , respectively, in the upper sides of which spraying devices  52  and  54 , respectively, are installed. 
         [0046]    In a manner described below it is possible to supply the spraying devices  52  and  54  with a cleaning liquid which can be sprayed into the cleaning compartments  44  and  46  in order to act upon the surface to be cleaned with the cleaning liquid. In the present case, water is used as cleaning liquid. To increase the cleaning effect, a chemical cleaning agent may be added to the water. 
         [0047]    Between the lower housing part  40  and the upper housing part  42  there are arranged between the roller-type brush  16  and a first transverse side  56  of the housing  12  and between the roller-type brush  18  and a second transverse side  58  of the housing  12  dirt pickup devices in the form of suction ledges  60  and  62 , respectively. As described below, these may be acted upon with negative pressure in order to remove by suction from the surface to be cleaned a mixture of dislodged dirt and cleaning liquid, the so-called “soiled liquor”. 
         [0048]    At its center, the housing  12  has a drive compartment  64  which is formed between the lower housing part  40  and the upper housing part  42  and accommodates a drive device  66 , the axis of rotation  68  of which is aligned parallel to the axes of rotation  20  and  22  of the roller-type brushes  16  and  18 , respectively. A driving force made available by the drive device  66  may be transmitted by gear mechanisms, known per se and not shown in the drawings, to the roller-type brushes  16  and  18  in order to rotatingly drive these for cleaning the surface to be cleaned. 
         [0049]    The upper housing part  42  has on the upper side  26  a dirty water tank receptacle  70  in the form of a tub-shaped depression, which is formed in the upper housing part  42 , the upper side of which is of approximately plate-shaped construction ( FIG. 5 ). The tub-shaped depression is delimited in the circumferential direction by a partially interrupted rim  72 . 
         [0050]    The dirty water tank  36  can be inserted into the dirty water tank receptacle  70  by a user without the need for tools and can be removed from it again without the need for tools. After removal of the dirty water tank  36  and the fresh water tank  38 , the scrubber vacuum  10  presents itself as shown in the plan view of  FIG. 2 , not, taking into account the push bar  28  which is not shown. 
         [0051]    As mentioned above, the fresh water tank  38  is placed on the dirty water tank  36  and is releasably connectable to it by connecting elements in the form of clamping brackets  74  and  76 . A transportation device in the form of a transportation bracket  78  serves for transportation of the dirty water tank  36  and the fresh water tank  38 . The transportation bracket  78  is mounted on the dirty water tank  36  for pivotal movement about an axis of rotation extending parallel to the axes of rotation  20  and  22  and can engage over the fresh water tank  38  during transportation. 
         [0052]    Cleaning liquid can be filled into the fresh water tank  38  through a fill-in opening which is closable by a cover  80 . Within the fresh water tank  38 , the cleaning liquid can be delivered through a withdrawal pipeline  82  arranged in the liquid tank to an outlet connection  84  which is arranged an a bottom wall  85  of the fresh water tank  38  ( FIG. 3 ). 
         [0053]    The dirty water tank  36  has a bottom wall  86  with two through-openings, of which only one through-opening  88  is to be seen in  FIG. 3 . There is arranged at these, facing upwards, a pipe connection  92  and  94 , respectively, over which two suction pipes  96  and  100 , respectively, are fitted, the open ends of which are located in the interior  100  of the dirty water tank  36 . 
         [0054]    When the dirty water tank  36  is arranged in the dirty water tank receptacle  70 , the through-openings  88  of the bottom wall  86  coincide with two through-openings  102  and  104 , respectively, ( FIG. 2 ), formed in the upper housing part  42 . Sealing elements  106  and  108  are arranged between the dirty water tank  36  and the upper housing part  42  at the through-openings  102  and  104 , respectively. 
         [0055]    From the through-openings  102  and  104  of the upper housing part  42  there extend in the direction of the surface to be cleaned pipe sections  110  and  112 , respectively, which are connected to the suction ledges  60  and  62 , respectively, ( FIG. 3 ). In this way, flow connections exist from the suction ledges  60  and  62  through the pipe sections  110  and  112 , respectively, the pipe connections  92  and  94 , respectively, and the suction pipes  96  and  98 , respectively, into the interior  100  of the dirty water tank  36 , with the upper housing part  42  carrying out, so to speak, an “interface function”. 
         [0056]    The bottom wall  86  of the dirty water tank  36  has a further through-opening  114 , from which there extends upwards a pipe connection  116  over which a U-shaped suction pipe  118  is fitted ( FIG. 4 ). 
         [0057]    In addition to the dirty water tank receptacle  70  mentioned above, there are formed on the upper housing part  42 , as is apparent from  FIGS. 2 and 5 , further receptacles for functional devices of the scrubber vacuum  10 . More particularly, there is formed on the upper housing part  42  a trough-shaped pump receptacle  120  for a liquid pump, which is not shown in the drawings because it is covered by a cover  122  which is releasably connectable to the upper housing part  42 . There is formed adjacent to the pump receptacle  120  a shaft-like electric receptacle  124  for an electric connection device in the form of a power strip, the power strip not being shown in the drawings either because it is also covered by the cover  122 . 
         [0058]    The liquid pump is in flow connection through a supply pipeline  126  and a valve  128 , which enters into fluid connection with the outlet connection  84  when the dirty water tank  36  is placed on the upper housing part  42 , with the withdrawal pipeline  82  and therefore with the interior of the fresh water tank  38 . 
         [0059]    Two outgoing pipelines  132  and  134  are connected to the outlet of the liquid pump by a T-shaped distributor pipeline  130 , the distributor pipeline  130  and the outgoing pipelines  132  and  134  being arranged in a groove-shaped pipeline receptacle  135  formed on the upper housing part  42 . 
         [0060]    The ends of the outgoing pipelines  132  and  134  facing away from the liquid pump are connected to the spraying devices  52  and  54 , respectively, by angled connection pieces  136  and  138 , respectively, arranged in trough-shaped receptacles  140  and  142 , respectively. The connection pieces  136  and  138  extend through through-openings  144  and  146 , respectively, of the upper housing part  42 . In this way, via the connection pieces  136  and  138 , respectively, cleaning liquid can be pumped by the liquid pump through the withdrawal pipeline  82 , the supply pipeline  126 , the distributor pipeline  130  and the outgoing pipelines  132  and  134  to the spraying devices  52  and  54 , respectively, in order to act upon the surface to be cleaned with the cleaning liquid. 
         [0061]    All of the connections of liquid-conducting components of the scrubber vacuum  10  are constructed as plug-in connections, i.e., the distributor pipeline  130  is connected by a plug-in connection to the outlet of the liquid pump and to the outgoing pipelines  132  and  134 , which, in turn, are connected by means of plug-in connections by the connection pieces  136  and  138 , respectively, to the spraying devices  52  and  54 , respectively. Likewise, the supply pipeline  126  is also pluggable onto the valve  128  and onto the inlet of the liquid pump. 
         [0062]    The use of plug-in connections allows a user of the scrubber vacuum  10 , in the event of a malfunction, to disconnect liquid-conducting pipelines in a simple way in order to exchange or clean them. Since the user is able to remove the dirty water tank  36  without the need for tools, these liquid-conducting components are accessible to him in a very easy way. In contrast to the liquid-conducting pipelines, the liquid pump and the power strip are covered by the cover  122  to prevent them from being touched. The cover  122  can be removed with a suitable tool by a service technician to allow him access to the liquid pump and the power strip. 
         [0063]    The electric lines to be connected to the power strip, of which one electric line  148  in the form of a mains cable is only shown to some extent in  FIG. 2 , are likewise connectable to the power strip by means of plug-in connections, which additionally increases the service amenability of the scrubber vacuum  10 . 
         [0064]    For vacuuming-off the mixture of dislodged dirt and cleaning liquid from the surface to be cleaned into the interior  100  of the dirty water tank  36  the scrubber vacuum  10  has a suction unit  150  with which a negative pressure can be generated in the interior  100  ( FIGS. 3 to 5 ). The suction unit  150  is drivable by electric energy and comprises for this purpose a motor  152  shown only diagrammatically with its outline in  FIGS. 3 and 4 . The motor  152  can drive a turbine wheel, not shown in the drawings, which is arranged in a turbine wheel housing  154 , likewise shown only diagrammatically with its outline. With a seal  156  on its underside, the suction unit  150  is placed on a rim  158  of a tub-shaped receptacle  160 , which is formed approximately at the center of the upper side  26  of the upper housing part  42 . 
         [0065]    A cover  162  covering the suction unit  150  is releasably connectable to the upper housing part  42 , in the present case, by screw connection with screws  164   a,    164   b,    164   c,    164   d,    164   e.  The cover  162  is two-part and has a lower cover part  166  releasably screwable to the upper housing part  42 , and an upper cover part  168  releasably connectable to the lower cover part  166 , in the present case, by screw connection with two screws  170   a,    170   b  ( FIGS. 2 and 5 ). 
         [0066]    The cover part  162  rests on the upper side of the suction unit  150 , so that the suction unit  150  is acted upon with force in the direction of the upper housing part  42  by the screw connection of the cover  162  to the upper housing part  42 . In this way, the suction unit  150  is held reliably in an accommodating compartment  172  on the upper housing part  42 , which is formed between the cover  162  and the upper housing part  42 . 
         [0067]    For maintenance and/or repair of the suction unit  150 , the cover  162  is freely accessible after removal of the dirty water tank  36  from the dirty water tank receptacle  70 . It is, for example, possible for a service technician to release the upper cover part  168  from the lower cover part  166  in order to gain access to an upper area of the suction unit  150  facing away from the upper housing part  42 . Should this limited access be inadequate for the maintenance and/or repair measure to be taken, he can also release the entire cover  162  from the upper housing part  42  and therefore completely expose the suction unit  150 . Since the suction unit  150  is held on the upper housing part  42  solely by the application of force by the cover  162 , there is no need for any further release of connecting mechanisms in order to release the suction unit  150  from the housing  12 . The scrubber vacuum  10  therefore has a particularly high level of service amenability. 
         [0068]    A plate-shaped cover element  174  rests on the rim  158  of the receptacle  160 . The cover element  174  comprises a first through-opening  176  which is arranged below the turbine wheel, and a second through-opening  178  which is arranged at the end of the cover element  174  that faces away from the suction unit  150  ( FIGS. 3 to 5 ). When the dirty water tank  36  is arranged in the dirty water tank receptacle  70 , the through-opening  178  coincides with the through-opening  114  in the bottom wall  86  of the dirty water tank  36 . A sealing filter element  180  is arranged between the dirty water tank  36  and the cover element  174 . In this way, there is formed between the cover element  174  and the upper housing part  42  an intake duct  182  by way of which the accommodating compartment  172  is in flow connection with the interior  100  through the pipe connection  116  and the suction pipe  118  for subjection of the interior  100  to a negative pressure. 
         [0069]    The cover element  174  is releasably connectable to the upper housing part  42 , in the present case, by connecting elements in the form of two screws  184   a ,  184   b  ( FIG. 2 ). This allows, after release of the cover  162  and the suction unit  150  from the housing  12 , the cover element  174  to be released from the housing  12 , which may be necessary, for example, when there is foreign matter in the intake duct  182 . 
         [0070]    After release of the dirty water tank  36  from the dirty water tank receptacle  70 , the filter element  180  is freely accessible, which also has an advantageous effect on the service amenability of the scrubber vacuum  10  as it is thereby made possible for the filter element  180  to be exchanged or cleaned in an easy way. 
         [0071]    Adjacent to the receptacle  160 , the upper housing part  42  has a tub-shaped depression  188  bordered by a rim  186 . The depression  188  opens into a shaft  190  which forms a through-opening  192  of the upper housing part  42  ( FIGS. 4 and 5 ). The shaft  190  is surrounded by a wall  194  which in the direction of the underside  14  of the housing  12  engages an opening  196  in the lower housing part  40 . The opening  196  expands in the direction of the surface to be cleaned in order to form in the delimiting wall  48  of the cleaning compartment  46  an outlet opening  198  of an exhaust air duct  200  which is formed in this way. 
         [0072]    The exhaust air duct  200  forms an exhaust air guiding device for the exhaust air of the suction unit  150 , and as well as by the upper housing part  42  and by the lower housing part  40  it is also delimited by a section of the cover  162  that covers the rim  186 . A flow connection is created between the accommodating compartment  172  and the cleaning, compartment  44  by the exhaust air duct  200 , so that exhaust air discharged by the suction unit  150  can be conducted through the exhaust air duct  200  into the cleaning compartment  44 . 
         [0073]    A flow of exhaust air discharged by the suction unit  150  can thereby be conducted through the exhaust air duct  200  onto the side of the roller-type brush  16  that faces away from the surface to be cleaned and is spatially distributed in an effective way by the roller-type brush  16  as a result of its rotary motion. This allows the noises of the flow of exhaust air of the suction unit  150  to be effectively reduced. 
         [0074]    As a result of the flow of exhaust air being conducted onto the side of the roller-type brush  16  that faces away from the surface to be cleaned, it can also be ensured that dirt on the surface to be cleaned will not be spatially distributed in an undesired manner and the cleaning result thereby impaired. 
         [0075]    Owing to the widening of the section of the exhaust air duct  200  in the area before the outlet opening  198 , the velocity of the flow of exhaust air is reduced before it enters the cleaning compartment  44 . The flow of exhaust air is directed approximately onto the center of the roller-type brush  16 , in relation to its longitudinal extent. These constructional measures have proven particularly effective in bringing about a reduction in the noise generation of the scrubber vacuum  10 . 
         [0076]    In a variant of the scrubber vacuum  10  it may be provided that the cleaning compartment  46  is also in flow connection with the accommodating compartment  172  for the suction unit  150  by way of an exhaust air duct in order to also direct a flow of exhaust air from the suction unit  150  onto the roller-type brush  18 .