vacuum cleaner nozzle

Abstract

Vacuum cleaner nozzle (1) with a housing (2), with a suction channel (6) formed in the housing (2), with a suction mouth (8) formed on an underside of the housing, extending in a transverse direction (y) and adjoining the suction channel (6), with a cleaning element (9) arranged in the suction channel (6) so as to be rotatable about an axis of rotation (d), with a transmission chamber (14) arranged next to the suction channel (6) in the transverse direction (y), and with an electric drive (12) arranged at least partially in the transmission chamber (14) and having an electric motor (13), which is mechanically coupled to the cleaning element (9) in the transmission chamber (14), characterized in that the electric drive (12) has a cooling air outlet (13b) which is fluidically connected to the transmission chamber (14).

Description

The invention relates to a vacuum cleaner nozzle having a housing, having a suction channel formed in the housing and having a suction mouth formed in an underside of the housing, extending in a transverse direction and adjoining the suction channel. In the suction channel, a cleaning element is arranged rotatably about an axis of rotation. In the transverse direction next to the suction channel, a transmission space is arranged. The vacuum cleaner nozzle further comprises an electric drive which is arranged at least partially in the transmission space and has an electric motor and is mechanically coupled to the cleaning element in the transmission space. The vacuum cleaner nozzle of the generic type is provided in particular for cleaning floor surfaces. The electric drive coupled to the cleaning element serves to set it in a rotational movement about the axis of rotation. As a result of this movement, the cleaning element can loosen dirt particles deposited on or in an in particular textile floor covering, so that these can be discharged by a suction air stream.The suction channel is provided in particular for connection to a suction air duct of a suction cleaning appliance or for connection to the suction air duct. For this purpose, the vacuum cleaner nozzle preferably has a suction connection, in particular a suction connection piece.The suction cleaning appliance has a fan for generating a suction air stream and at least one separating device for separating dirt particles carried along in the suction air stream. The separating device can be designed in particular as a cyclone filter and / or filter bag.In particular, the vacuum cleaner nozzle according to the invention is suitable for use with a floor vacuum cleaner (canister cleaner), an upright vacuum cleaner (upright cleaner), a hand vacuum cleaner, battery-operated vacuum cleaners with a rigid suction pipe (stick cleaner) and / or vacuum cleaner installations fixedly installed in a building. To supply the electric motor, the suction cleaning devices used or suction lines connecting these to the vacuum cleaner nozzle preferably have electrical supply lines. Integration into an robotic vacuum is also possible.A problem with severe stress-in particular when used on high-pile carpets-is that a considerable amount of waste heat arises in the electric motor due to severe mechanical stress. This removal is of decisive importance both for the operational reliability and the service life of the vacuum cleaner nozzle. This is made more difficult by the fact that, especially in load situations, the rotational speed of the electric motor regularly decreases, so that forced ventilations coupled to the electric motor are throttled in a disadvantageous manner.Therefore, in the past, so-called missing air currents have often been used for cooling the electric motor. These make use of the air guidance that a lower pressure level prevails within the suction channel than at the outer side of the vacuum cleaner nozzle. Suitable secondary air openings have thereby sucked in a (clean) air stream from the outside of the vacuum cleaner nozzle, led past the electric motor and led into the suction channel. This air flow is, however, no longer available for cleaning purposes.It has therefore already been proposed in EP 2 064 979 to discharge the cooling air at the underside of the vacuum cleaner nozzle so that the latter can be sucked in through the suction mouth. The cooling air stream is thus further accessible to the cleaning effect. However, in order to generate a sufficient negative pressure on the nozzle bottom side, the cooling air must be discharged in a region which is at least partially sealed with respect to the environment.Unfortunately, the efficiency of this solution still leaves much to be desired. Thus, the pressure level that can be reached at the underside of the vacuum cleaner nozzle is not sufficient to generate a sufficiently large suction air flow. Also, so-called "suction fast" - a situation in which the negative pressure inside the suction channel causes the closing of the suction mouth and the interruption of the suction air flow - simultaneously also leads to an interruption of the cooling air flow. In this scenario, on the contrary, an increased suction air flow is rather required.Against the background of relevant energy saving regulations in the EU or in battery-operated devices, it is also very difficult to use non-cleaning-active secondary air streams for cooling. Thus, the cleaning performance would decrease too much in relation to the electrical energy used.Against this background, the invention is based on the object of optimizing the cooling air guidance in a generic vacuum cleaner nozzle. In this case, a reliable supply of cooling air should be ensured and the cleaning effect should not be impaired.The subject matter of the invention and the solution of this object is a vacuum cleaner nozzle according to claim 1.According to the invention, it is provided that the electric motor has a cooling air outlet which is connected fluidically to the transmission chamber. Since the rotating cleaning element is coupled to the electric drive in the transmission chamber, it could only be sealed off from the suction chamber with a cost that is disproportionately high for vacuum cleaner nozzles. Rather, the transmission chamber and the suction channel are also connected to one another in terms of flow in the region of the cleaning element. This makes it possible for the negative pressure prevailing in the suction channel during operation to generate a pressure drop to the transmission space and thus indirectly also to the cooling air outlet of the electric motor.As a result, a heated cooling air stream emerging from the cooling air outlet during operation can be discharged into the transmission space and thus subsequently into the suction duct. Since the transmission chamber cannot be completely sealed off from the suction duct in any case, no additional incorrect air flows are created. Rather, this air flow is directed by the fluidic connection of the air outlet to the transmission space in such a way that it can also guide waste heat away from the electric motor as a further benefit.Since the cooling air flow enters the suction channel, it can likewise become cleaning-effective there by removing dirt particles which have been agitated up by the cleaning element. The cleaning performance is therefore likewise not impaired by the measures according to the invention.A further advantage of the invention is that in the event of suction being fixed, the cooling air flow is not impeded. On the contrary, the vacuum inside the suction duct increases, so that a larger cooling air flow is formed, which enables an improved heat removal from the additionally loaded electric motor.According to a preferred embodiment, the electric drive has a drive wheel arranged in the transmission space. The drive wheel can be set into a rotational movement by the electric motor. It is at the same time configured to transmit this rotational movement to the cleaning element by mechanical coupling.According to a particularly preferred embodiment, the electric motor is arranged outside the transmission chamber. The drive wheel arranged in the transmission space is connected to the electric motor by a drive shaft which runs through a conversion of the transmission space. As a result, the electric motor is encapsulated by the transmission chamber-and also by the suction channel. Any dirt particles present in the transmission chamber or passing from the suction channel into the transmission chamber are thus better kept away from the electric motor. Since the electric motor is expediently at a higher pressure level than the transmission space during operation, complete sealing (for example by means of a shaft seal) is not required. Rather, the space between the electric drive and the wall is flushed by an air stream during operation.According to a preferred embodiment, an annular gap of less than 0.3 mm, preferably between 0.05 mm and 0.1 mm, is formed between the wall of the transmission chamber and the electric drive. An annular gap of this size can, on the one hand, reliably prevent mechanical contact between movable parts of the electric drive and the wall, while excessively large secondary air currents are not to be expected. The annular gap preferably has a flow cross section of less than 10 mm 2, in particular less than 4 mm 2 very particularly preferably 2 mm 2 or less. The annular gap is bounded on the one hand by the wall and on the other hand in particular by the motor housing, a non-rotating part of the electric motor, the motor shaft and / or the drive wheel.According to an alternative preferred variant, the electric drive is inserted sealingly into the wall of the transmission chamber, so that no annular gap remains.The electric motor preferably has a motor housing, wherein the cooling air outlet of the electric drive is formed on the motor housing and the motor housing further has at least one cooling air inlet. The cooling air outlet is connected to the transmission space by an exhaust air line. The cooling air flow is directed through the exhaust air line in such a way that the heated cooling air emerging from the motor housing during operation is discharged directly with the exhaust air line and fed to the transmission space. This allows the cooling power achieved with a given cooling air flow to be maximized.According to a preferred embodiment, the electric motor has an impeller inside the motor housing for conveying the cooling air. The latter actively conveys the cooling air flow from the cooling air inlet in the direction of the cooling air outlet.Particularly preferably, the exhaust air line has a line cross section between 20 mm 2 and 100 mm 2. An exhaust air duct dimensioned in this way is suitable for receiving all the cooling air flowing out of the cooling air outlet and for forwarding it to the transmission space with low flow resistanceAccording to a preferred embodiment, the exhaust air line is designed as a pipeline. A pipeline has at least geometrically similar cross-sectional areas adjoining one another in particular. The pipeline is preferably designed with a constant flow cross section and / or a constant cross-sectional shape. In particular, the pipeline can be formed with a round, oval or polygonal cross section.According to a first alternative, the exhaust air line can be inserted into the housing as a separate component. This facilitates the manufacturing process. In particular, the separately formed exhaust air line can also be formed differently from the material of the housing. It is also conceivable to design the exhaust air line from a flexible material-for example as a rubber hose.According to an alternative embodiment, the exhaust air line is integrated into the housing. In this case, for example, a flow channel can be formed by two parallel wall sections, which simultaneously functions as an exhaust air line.Particularly preferably, the exhaust air line is sealingly connected to the motor housing. This contributes to an additional steering of the cooling air flow, since the pressure level of the transmission space-mediated by the exhaust air line-is concentrated in a targeted manner at the cooling air outlet. Air drawn off via the exhaust air line is thereby forcibly guided through the motor housing.Particularly preferably, the exhaust air line opens into a wall of the transmission chamber. From there, it directly adjoins the pressure level of the transmission chamber.The cleaning element preferably has a cleaning roller equipped with cleaning agents, in particular bristles, and a drive element which can be detachably connected to the cleaning roller and is coupled to the electric drive. This division into at least two parts enables a functional separation: while the drive element is optimized for the mechanical coupling to the electric drive, the cleaning roller is provided for the ground contact. The cleaning agents can protrude at least partially from the suction mouth.Expediently, the cleaning roller and the drive element are connected to one another in a form-fitting manner by a driver profile. In particular, one of the two connection partners has a projection which engages in an associated receptacle of the other connection partner in a positive-locking manner.This projection can additionally have rib extensions for transmitting the rotational movement to its outer wall side, which engage in associated receiving slots of the receptacle. For improved coupling, the rib extensions (and correspondingly the receiving slots) can be helically wound. As a result, when the rotational movement is transmitted from the drive element to the cleaning roller, an axial torque effective in the direction of the rotational axis is additionally exerted. Particularly preferably, the helix is inclined in such a way that the axial moment draws the cleaning roller in the direction of the drive element during operation.According to a particularly preferred embodiment, the drive element is mounted on the housing in a fixed position and rotatable about the drive axis of rotation. This facilitates the mechanical coupling to the electric drive, since the drive element does not have to be repositioned.Expediently, the cleaning roller is designed to be removable from the housing. Since dirt particles and fibers or hair can accumulate on the cleaning element again and again during operation, it is advantageous to remove the latter for cleaning purposes. The division of the cleaning element into two is of further advantage, since only the cleaning roller has to be removed.According to a preferred embodiment, the electric drive and the cleaning element are coupled to one another by a gear. A possible drive wheel is in particular designed as a gearwheel which-optionally with the interposition of one or more additional gearwheels-couples to the cleaning element. In this case, in particular a drive element can be connected to a gearwheel or partially embodied in the form of a gearwheel.According to an alternative embodiment, the electric drive and the cleaning element are coupled to one another by an endlessly circulating drive means, in particular a toothed belt. Thus, a connection which is particularly insensitive to soiling and quiet is provided. In particular, an elastically designed revolving drive means can also serve as a mechanical buffer between the electric drive and the cleaning element.Preferably, the transmission space is divided from the suction channel by a partition wall. The partition wall has an opening formed with a boundary, through which the cleaning element protrudes. Between the boundary and the cleaning element, in particular the cleaning roller, an annular channel is formed. This annular channel can serve within the scope of the invention as a fluidic connection between the transmission chamber and the suction channel. As a result, the cooling air stream can be transferred from the transmission space into the suction channel and discharged there.According to a particularly preferred embodiment, the annular channel has a size (measured radially, i.e. perpendicularly to the axis of rotation) between 0.5 mm and 2 mm, in particular between 0.5 mm 1 mm. Particularly preferably, the annular channel is formed with a width of approximately 0.7 mm. With this size, a sufficient cooling air flow can be generated. At the same time, a transmission of dirt particles from the suction channel into the transmission chamber is sufficiently prevented.Particularly preferably, the annular channel has a cross-sectional area between 20 mm 2 and 100 mm 2. Within the scope of the invention, it is very particularly preferably provided that the cross-sectional area of the annular channel is in a ratio between 1:2 and 2:1 to the flow cross-section of the connection of the cooling air outlet to the transmission space-in particular the exhaust air line. Particularly preferably, the two flow cross sections are designed to be approximately the same size.Preferably, the electric motor is arranged at least partially, in particular with any motor housing, preferably completely in a motor chamber formed in the housing. The motor chamber serves for structural separation and encapsulation of the electric motor. This can protect the latter mechanically and against damage to dirt. Furthermore, it serves to direct the cooling air flow.Particularly preferably, the motor chamber has at least one air inlet opening. This is a defined air opening which connects the motor chamber to a higher pressure level during operation, in particular to the outside of the vacuum cleaner nozzle. As a result of the negative pressure applied via the suction channel and the transmission chamber to the cooling air outlet of the electric drive, fresh air can be sucked in simultaneously via the inlet air opening from the higher pressure level or from the environment. The inlet air opening can also be connected only indirectly to the outer side of the housing.The inlet air opening preferably has a flow cross section of at least 50 mm 2, in particular at least 70 mm 2, very particularly preferably at least 100 mm 2. It is advantageously provided that the inlet air opening has a larger flow cross section than the fluidic connection of the cooling air outlet to the transmission chamber.It is very particularly preferred that the supply air opening is arranged in a region of the motor chamber which--with respect to the electric motor--is situated opposite the cooling air inlet. Within the scope of the cooling air flow provided, it is achieved that the cooling supply air initially passes an outer side of the motor housing before it reaches the interior thereof via the cooling air inlet. Subsequently, it is further heated there and removed in a targeted manner via the cooling air outlet within the scope of the invention.The invention is explained below with reference to figures illustrating only one exemplary embodiment. They show schematically: FIG. 1 shows a perspective illustration of a vacuum cleaner nozzle according to the invention with a partially broken-open housing, FIG. 2 is a bottom view of the nozzle of FIG. 1; and FIG. 3 is a partial horizontal section along the plane A-A of FIG. 1.FIG. 1 shows a vacuum cleaner nozzle 1 according to the invention with a partially broken-open illustrated housing 2. the housing 2 extends in a working direction x, a transverse direction y and in a vertical direction z perpendicular to the working direction x and the transverse direction y. The vacuum cleaner nozzle 1 is a so-called double joint nozzle with an intermediate piece 3 adjoining the housing 2 so as to be pivotable about a pivot axis extending in the transverse direction and a suction connection piece 4 which is likewise configured so as to be pivotable relative to the working direction x at the rear end of the intermediate piece 3.The partially broken open housing 2 shows a suction channel 6 on the inside, which extends substantially in the transverse direction y and is connected in terms of flow to the suction connection piece 4 via a suction line 7.A comparative view with the bottom view from FIG. 2 reveals that a suction mouth 8 is formed on the underside of the housing 2-in relation to the vertical direction z-which suction mouth is bounded by a front suction mouth edge 8 aand a rear suction mouth edge 8 bin relation to the working direction x and furthermore adjoins the suction channel 6 arranged above it.In the suction channel 6, a cleaning element 9 is arranged rotatably about an axis of rotation d running in the transverse direction y. The cleaning element 9 comprises a cleaning roller 10 which is provided with cleaning agents in the form of bristle tufts 10a and cleaning lips 10b. In the exemplary embodiment shown, the cleaning roller 10 is designed to be removable from the housing 2. For driving, the cleaning element 9 additionally has a drive element 11 which can be connected to the cleaning roller 10 and is mounted in the housing 2 in a fixed and rotatable manner about the axis of rotation d. For connection to the cleaning roller 10, the drive element 11 has a drive pin, not shown, which projects into an associated receptacle of the cleaning roller 10.The vacuum cleaner nozzle 1 according to the invention additionally has an electric drive 12 with an electric motor 13. In the transverse direction y next to the suction channel, a transmission space 14 is furthermore formed, in which the electric drive 12 is mechanically coupled to the cleaning element 9.The electric motor 13 is formed with a motor housing 13a having a cooling air outlet 13b. According to the invention, the cooling air outlet 13 bis fluidically connected to the transmission space 14. In the exemplary embodiment shown, this is effected by an exhaust air line 15.This is sealingly connected to the motor housing 13 aand opens into a wall 14 aof the transmission chamber 14.As can be seen in particular from FIG. 3, the housing 13 aof the electric motor 13 is arranged completely within a motor chamber 17 formed in the housing 2. The electric drive 12 comprises a drive wheel 12 aarranged in the transmission space 14. This is connected to the electric motor 13 by a motor shaft 13c which extends through the wall 14a of the transmission chamber. An annular gap s 1 of less than 1 mm remains between the wall 14a of the transmission chamber 14 and the drive shaft 13c.The wall 14 aof the transmission chamber 14 furthermore forms a partition wall 16 with respect to the suction channel 6. The partition wall 16 has an opening 16 bformed with a boundary 16 a, through which the cleaning element 9 protrudes. In the exemplary embodiment shown, in the region of the opening 16 b, the outermost edge of the cleaning element 9 is formed by the roller body of the cleaning roller 10. Between the boundary 16 aand the cleaning roller 10 there remains an annular channel s 2 between 0.5 mm and 2 mm, which fluidically connects the transmission chamber 14 to the suction channel 6.In the exemplary embodiment shown, the electric drive 12 is connected via its drive wheel 12 athat is rotatable about a drive axis a to the drive element 11 of the cleaning roller 9 by an endlessly revolving drive means in the form of a toothed belt 18. For this purpose, a part of the drive element 11 is designed as a drive pinion 11 a, over which the toothed belt 18 runs. The drive axis a and the rotational axis d are oriented parallel to one another in the transverse direction y and are arranged one behind the other with respect to the working direction x. The drive axis a is preferably arranged at at least the same height with respect to the vertical direction z.The air guidance is indicated in FIG. 3 by arrows. The motor chamber 17 has an air supply port 17a which connects it to the outside of the housing 2. The air inlet opening 17a opens into an intermediate gap between the housing 2 and the intermediate piece 3.Within the scope of the exemplary embodiment shown, the electric motor 13 has a cooling air inlet 13 d. This is arranged on the side of the motor housing 13 afacing away from the inlet air opening 17 a. As a result, a flow of cooling air that has entered through the air supply port 17a first passes the outside of the motor housing 13a before entering the inside of the motor housing 13a through the cooling air inlet 13d. There, it is further heated by the waste heat of the electric motor and exits from the motor housing 13 athrough the cooling air outlet 13 band is transferred through the exhaust air line 15 into the transmission space 14. Due to the pressure drop prevailing during operation, the cooling air flow is finally guided through the annular channel 2 into the suction channel 6 and is drawn off there together with the suction air flow through the suction line 7 in the direction of the suction connection piece 4.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedEP 2 064 979

[0007]

Claims

Vacuum cleaner nozzle (1) having a housing (2), having a suction channel (6) formed in the housing (2), having a suction mouth (8) formed on an underside of the housing and extending in a transverse direction (y) and adjoining the suction channel (6), having a cleaning element (9) arranged in the suction channel (6) such that it can rotate about an axis of rotation (d), having a transmission space (14) arranged next to the suction channel (6) in the transverse direction (y), and having an electric drive (12) arranged at least partially in the transmission space (14) and having an electric motor (13), which is mechanically coupled to the cleaning element (9) in the transmission space (14), characterized in that the electric drive (12) has a cooling air outlet (13b), which is connected fluidically to the transmission space (14).Vacuum cleaner nozzle (1) according to claim 1, characterised in that the electric drive (12) has a drive wheel (12a) arranged in the transmission space (14).Vacuum cleaner nozzle (1) according to claim 2, characterised in that the electric motor (13) is arranged outside the transmission chamber (14), that the drive wheel (12a) is connected to the electric motor (13) by a drive shaft (13c), which runs through a wall (14a) of the transmission chamber (14).Vacuum cleaner nozzle (1) according to claim 3, characterised in that an annular gap (s 1) of less than 1 mm, preferably between 0.01 mm and 0.1 mm remains between the wall (14a) of the transmission chamber (14) and the electric drive (12).Vacuum cleaner nozzle (1) according to one of Claims 1 to 4, characterized in that the electric motor (13) has a motor housing (13a), which forms the cooling air outlet (13b) and has at least one cooling air inlet (13d), and in that the cooling air outlet (13b) is connected to the transmission space (14) by an exhaust air line (15).Vacuum cleaner nozzle (1) according to claim 5, characterised in that the exhaust air line (15) has a line cross-section between 4 mm 2 and 30 mm 2.Vacuum cleaner nozzle (1) according to claim 5 or 6, characterised in that the exhaust air line (15) is designed as a pipeline.Vacuum cleaner nozzle (1) according to one of claims 5 to 7, characterised in that the exhaust air line (15) is integrated into the housing (2).Vacuum cleaner nozzle (1) according to one of Claims 5 to 8, characterized in that the exhaust air line (15) connects sealingly to the motor housing (13a).Vacuum cleaner nozzle (1) according to one of Claims 5 to 9, characterized in that the exhaust air line (15) opens out in a wall (14a) of the transmission space (14).Vacuum cleaner nozzle (1) according to one of Claims 1 to 10, characterized in that the cleaning element (9) has a cleaning roller (10) which is occupied by cleaning means (10a, 10b), in particular by bristles (10a), and a drive element (11) which can be detachably connected to the cleaning roller (10) and is coupled to the electrical drive (12).Vacuum cleaner nozzle (1) according to claim 11, characterised in that the drive element (11) is mounted on the housing (2) in a fixed manner and rotatably about the axis of rotation (d).Vacuum cleaner nozzle (1) according to claim 11 or 12, characterised in that the cleaning roller (10) can be removed from the housing (2).Vacuum cleaner nozzle (1) according to one of claims 1 to 13, characterised in that the electric drive (12) and the cleaning element (9) are coupled to one another by a gear mechanism.Vacuum cleaner nozzle (1) according to one of claims 1 to 13, characterised in that the electric drive (12) and the cleaning roller (9) are coupled by an endlessly revolving drive means, in particular a toothed belt (18).Vacuum cleaner nozzle (1) according to one of Claims 1 to 15, characterized in that the transmission space (14) is divided from the suction channel (6) by a dividing wall (16), in that the dividing wall (16) has an opening (16b) which is formed with a boundary (16a) and through which the cleaning element (9) projects, and in that an annular channel (s 2) is formed between the boundary (16a) and the cleaning element (9), in particular the cleaning roller (10).Vacuum cleaner nozzle (1) according to claim 16, characterised in that the annular channel (s 2) has a size measured perpendicular to the axis of rotation (d) of between 0.5 mm 2 mm, in particular between 0.5 mm and 1 mm.Vacuum cleaner nozzle (1) according to one of claims 1 to 17, characterised in that the electric motor (13) is arranged at least partially, in particular with a motor housing (13a), preferably completely in a motor chamber (17) formed in the housing (2).Vacuum cleaner nozzle (1) according to claim 18, characterised in that the motor chamber (17) has at least one inlet air opening (17a).Vacuum cleaner nozzle (1) according to claim 19 and one of claims 5 to 10, characterised in that the supply air opening (17a) is arranged in a region of the motor chamber (17) which, with respect to the electric motor (13), is opposite the cooling air inlet (13d).

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