VACUUM CLEANER NOZZLE

Description

[0001] The invention relates to a vacuum cleaner nozzle with a housing, with a suction channel formed in the housing and with a suction mouth formed in an underside of the housing, extending in a transverse direction and adjoining the suction channel. A cleaning element is arranged in the suction channel so as to be rotatable about a rotation axis. A transmission chamber is arranged in the transverse direction next to the suction channel. The vacuum cleaner nozzle further comprises an electric drive which is arranged at least partially in the transmission chamber and has an electric motor, which is mechanically coupled to the cleaning element in the transmission chamber. The generic vacuum cleaner nozzle is intended in particular for cleaning floor surfaces. The electric drive coupled to the cleaning element serves to set the latter in a rotational movement about the rotation axis.As a result of this movement, the cleaning element can loosen dirt particles deposited on or in a particularly textile floor covering so that they can be removed by a suction air stream.

[0002] The suction channel is particularly intended to be connected to a suction air duct of a vacuum cleaning device or to the suction air duct. For this purpose, the vacuum cleaner nozzle preferably has a suction connection, in particular a suction connection piece.

[0003] The vacuum cleaning device comprises a fan for generating a suction air stream and at least one separator for separating dirt particles entrained in the suction air stream. The separator can be designed, in particular, as a cyclone filter and / or filter bag.

[0004] The vacuum cleaner nozzle according to the invention is particularly suitable for use with a canister vacuum cleaner, an upright vacuum cleaner, a handheld vacuum cleaner, battery-operated vacuum cleaners with a rigid suction tube (stick cleaner), and / or vacuum cleaner systems permanently installed in a building. To supply the electric motor, the vacuum cleaners used, or the suction lines connecting them to the vacuum cleaner nozzle, preferably have electrical supply lines. Integration into a robot vacuum cleaner is also possible.

[0005] A problem with heavy use—especially on deep-pile carpets—is that the electric motor generates a significant amount of waste heat due to the heavy mechanical stress. Efficiently dissipating this heat is crucial for both operational reliability and the service life of the vacuum cleaner nozzle. This is further complicated by the fact that the speed of the electric motor regularly drops, especially under load, which adversely affects any forced ventilation systems coupled to the electric motor.

[0006] For this reason, so-called secondary airflows were often used in the past to cool the electric motor. These systems utilize the fact that the air flow inside the suction channel is lower than that on the outside of the vacuum cleaner nozzle. Through suitable secondary air vents, a (clean) airflow was drawn in from the outside of the vacuum cleaner nozzle, bypassed the electric motor, and directed into the suction channel. However, this airflow is no longer available for cleaning purposes.

[0007] Therefore, it was already proposed in EP 2 064 979 to direct the cooling air through the underside of the vacuum cleaner nozzle so that it can be sucked in through the suction nozzle. The cooling air stream is thus still accessible for cleaning. However, in order to create a sufficient negative pressure on the underside of the nozzle, the cooling air must be released into an area that is at least partially sealed from the environment.

[0008] Unfortunately, the efficiency of this solution still leaves much to be desired. For example, the pressure level achievable at the bottom of the vacuum cleaner nozzle is insufficient to generate a sufficiently large suction airflow. Furthermore, a so-called "suction jam" – a situation in which the negative pressure within the suction channel causes the suction nozzle to close and the suction airflow to interrupt – also simultaneously interrupts the cooling airflow. In this scenario, on the contrary, a stronger suction airflow is required.

[0009] Furthermore, given the relevant energy-saving regulations in the EU and battery-operated devices, it is very difficult to use secondary airflows that do not actively clean the air for cooling. This would significantly reduce the cleaning performance relative to the electrical energy used.

[0010] From JP 2002 165 733 A it is known to guide the cooling air through the transmission chamber.

[0011] Against this background, the invention is based on the task of optimizing the cooling air flow in a vacuum cleaner nozzle of this type. This should ensure a reliable supply of cooling air without compromising the cleaning effect.

[0012] The subject of the invention and the solution to this problem is a vacuum cleaner nozzle according to claim 1. Preferred embodiments are specified in the dependent subclaims.

[0013] According to the invention, the electric motor has a cooling air outlet that is fluidically connected to the transmission chamber. Since the rotating cleaning element is coupled to the electric drive in the transmission chamber, sealing it from the suction chamber would require disproportionate effort for vacuum cleaner nozzles. Rather, the transmission chamber and the suction channel in the area of ​​the cleaning element are also fluidically connected. This makes it possible for the negative pressure prevailing in the suction channel during operation to generate a pressure gradient to the transmission chamber and thus indirectly also to the cooling air outlet of the electric motor.

[0014] As a result, a heated cooling air flow escaping from the cooling air outlet during operation can be diverted into the transmission chamber and subsequently into the intake duct. Since the transmission chamber cannot be completely sealed from the intake duct anyway, no additional leakage air flows are created. Rather, this air flow is directed by the fluidic connection between the air outlet and the transmission chamber in such a way that it can also dissipate waste heat from the electric motor, providing an additional benefit.

[0015] Since the cooling air stream enters the intake duct, it can also have a cleaning effect there by carrying away dirt particles stirred up by the cleaning element. Therefore, the cleaning performance is also not impaired by the measures according to the invention.

[0016] A further advantage of the invention is that in the event of a suction jam, the cooling air flow is not obstructed. On the contrary, the negative pressure within the intake channel increases, creating a larger cooling air flow, which enables improved heat dissipation from the additionally loaded electric motor.

[0017] According to a preferred embodiment, the electric drive comprises a drive wheel arranged in the transmission chamber. The drive wheel can be set in rotation by the electric motor. At the same time, it is configured to transmit this rotation to the cleaning element via mechanical coupling.

[0018] According to a particularly preferred embodiment, the electric motor is arranged outside the transmission chamber. The drive wheel arranged in the transmission chamber is connected to the electric motor by a drive shaft which runs through a wall of the transmission chamber. This encapsulates the electric motor from the transmission chamber - and also indirectly from 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 chamber during operation, complete sealing (for example by a shaft seal) is not necessary. Instead, the space between the electric drive and the wall is flushed by an air stream during operation.

[0019] 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 moving parts of the electric drive and the wall, while no excessively large secondary air flows are 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<, most preferably 2 mm 2< or less. The annular gap is delimited 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.

[0020] According to an alternative preferred variant, the electric drive is sealingly inserted into the wall of the transmission chamber so that no annular gap remains.

[0021] According to the invention, the electric motor comprises a motor housing, wherein the cooling air outlet of the electric drive is formed on the motor housing, and the motor housing further comprises at least one cooling air inlet. The cooling air outlet is connected to the transmission chamber via an exhaust air duct. The exhaust air duct directs the cooling air flow such that the heated cooling air escaping from the motor housing during operation is directly discharged via the exhaust air duct and fed into the transmission chamber. This maximizes the cooling performance achieved with a given cooling air flow.

[0022] According to a preferred embodiment, the electric motor has an impeller within the motor housing for conveying the cooling air. This impeller actively promotes the cooling air flow from the cooling air inlet toward the cooling air outlet.

[0023] Particularly preferably, the exhaust air duct has a cross-section between 20 mm 2 and 100 mm 2 . An exhaust air duct dimensioned in this way is suitable for collecting all the cooling air flowing from the cooling air outlet and for passing it on to the transmission chamber with low flow resistance.

[0024] According to a preferred embodiment, the exhaust air duct is designed as a pipe. A pipe, in particular, has at least geometrically similar cross-sectional areas that adjoin one another. The pipe is preferably designed with a constant flow cross-section and / or a consistent cross-sectional shape. In particular, the pipe can be designed with a round, oval, or polygonal cross-section.

[0025] According to a first alternative, the exhaust duct can be integrated into the housing as a separate component. This simplifies the manufacturing process. In particular, the separately formed exhaust duct can also be constructed from a different material than the housing. It is also conceivable to construct the exhaust duct from a flexible material—for example, a rubber hose.

[0026] According to an alternative embodiment, the exhaust air duct is integrated into the housing. For example, two parallel wall sections can be used to form a flow channel that also functions as an exhaust air duct.

[0027] Particularly preferably, the exhaust air duct is sealed to the engine housing. This contributes to additional control of the cooling air flow, as the pressure level of the transmission chamber—mediated by the exhaust air duct—is specifically concentrated at the cooling air outlet. Air extracted via the exhaust air duct is thereby forced through the engine housing.

[0028] Particularly preferably, the exhaust air duct opens into a wall of the transmission chamber. From there, it connects directly to the pressure level of the transmission chamber.

[0029] The cleaning element preferably comprises a cleaning roller equipped with cleaning agents, in particular bristles, and a drive element that can be releasably connected to the cleaning roller and is coupled to the electric drive. This division into at least two parts enables functional separation: While the drive element is optimized for mechanical coupling to the electric drive, the cleaning roller is designed for floor contact. The cleaning agents can protrude at least partially from the suction nozzle.

[0030] The cleaning roller and the drive element are expediently connected to each other in a form-fitting manner by a driver profile. In particular, one of the two connecting partners has a projection that engages in a form-fitting manner in an associated receptacle of the other connecting partner.

[0031] To transmit the rotary motion to its outer wall, this projection can additionally have rib extensions that engage in associated receiving slots of the receptacle. For improved coupling, the rib extensions (and correspondingly the receiving slots) can be spirally wound. As a result, an additional axial moment acting in the direction of the rotational axis is exerted upon transmission of the rotary motion from the drive element to the cleaning roller. Particularly preferably, the spiral is inclined in such a way that the axial moment pulls the cleaning roller toward the drive element during operation.

[0032] According to a particularly preferred embodiment, the drive element is mounted on the housing in a stationary manner and can rotate about the drive axis of rotation. This facilitates the mechanical coupling with the electric drive, since the drive element does not need to be repositioned.

[0033] The cleaning roller is conveniently designed to be removable from the housing. Since dirt particles, fibers, or hair can continually accumulate on the cleaning element during operation, it is advantageous to remove it periodically for cleaning purposes. The two-part design of the cleaning element is a further advantage, as only the cleaning roller needs to be removed.

[0034] According to a preferred embodiment, the electric drive and the cleaning element are coupled to each other by a gear mechanism. Any drive wheel is designed, in particular, as a gear, which—optionally with the interposition of one or more additional gears—couples to the cleaning element. In particular, a drive element can be connected to a gear or be partially gear-shaped.

[0035] According to an alternative embodiment, the electric drive and the cleaning element are coupled to each other by a continuously rotating drive means, in particular a toothed belt. This provides a connection that is particularly resistant to dirt and quiet. In particular, an elastically designed rotating drive means can also serve as a mechanical buffer between the electric drive and the cleaning element.

[0036] Preferably, the transmission chamber is separated from the suction channel by a partition wall. The partition wall has an opening formed with a border through which the cleaning element protrudes. An annular channel is formed between the border and the cleaning element, in particular the cleaning roller. Within the scope of the invention, this annular channel can serve as a fluidic connection between the transmission chamber and the suction channel. This allows the cooling air flow from the transmission chamber to be transferred into the suction channel and discharged there.

[0037] According to a particularly preferred embodiment, the annular channel has a size (radially, i.e., measured perpendicular to the rotation axis) of between 0.5 mm and 2 mm, in particular between 0.5 mm and 1 mm. The annular channel is particularly preferably designed with a width of approximately 0.7 mm. At this size, a sufficient cooling air flow can be generated. At the same time, the transfer of dirt particles from the suction channel into the transmission chamber is sufficiently prevented.

[0038] 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 particularly preferred that the cross-sectional area of ​​the annular channel be in a ratio of between 1:2 and 2:1 to the flow cross-section of the connection between the cooling air outlet and the transmission chamber—in particular, the exhaust air duct. Particularly preferably, the two flow cross-sections are approximately the same size.

[0039] Preferably, the electric motor is arranged at least partially, in particular with any motor housing, preferably entirely, in a motor chamber formed in the housing. The motor chamber serves to structurally separate and encapsulate the electric motor. This allows it to be mechanically protected and protected from dirt. Furthermore, it serves to direct the cooling air flow.

[0040] Particularly preferably, the motor chamber has at least one air intake opening. This is a defined air intake opening that connects the motor chamber to a higher pressure level during operation, in particular the outside of the vacuum cleaner nozzle. Due to the negative pressure applied to the cooling air outlet of the electric drive via the suction channel and the transmission chamber, fresh air from the higher pressure level or from the environment can be drawn in simultaneously through the air intake opening. The air intake opening can also be connected only indirectly to the outside of the housing.

[0041] Preferably, the supply air opening has a flow cross-section of at least 50 mm 2 , in particular at least 70 mm 2 , most preferably at least 100 mm 2 . It is advantageously provided that the supply air opening has a larger flow cross-section than the fluidic connection of the cooling air outlet to the transmission space.

[0042] It is particularly preferred that the air intake opening be located in a region of the motor chamber that—relative to the electric motor—is opposite the cooling air inlet. Within the scope of the intended cooling air flow, the cooling air intake first passes along the outer side of the motor housing before entering the interior via the cooling air inlet. It is then further heated there and, within the scope of the invention, selectively extracted via the cooling air outlet.

[0043] The invention is explained below with reference to figures illustrating only one exemplary embodiment. They show schematically: Fig. 1 a perspective view of a vacuum cleaner nozzle according to the invention with a partially broken housing, Fig. 2 a bottom view of the nozzle from Fig. 1 and Fig. 3 a partial horizontal section along the plane AA of Fig. 1 .

[0044] The Fig. 1 shows a vacuum cleaner nozzle 1 according to the invention with a partially broken-away 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-jointed nozzle with an intermediate piece 3 which is connected to the housing 2 and can be pivoted about a pivot axis running in the transverse direction and with a suction connection piece 4 which is also designed to be pivotable with respect to the working direction x at the rear end of the intermediate piece 3. Furthermore, the intermediate piece 3 carries two rear rollers 5, the axis of rotation 5a of which is aligned with a second pivot axis about which the suction connection piece 4 is articulated on the intermediate piece.

[0045] Through the partially broken-open housing 2, a suction channel 6 can be seen inside, which extends essentially in the transverse direction y and is fluidically connected to the suction connection piece 4 via a suction line 7.

[0046] A comparative view with the bottom view from Fig. 2 It can be seen that on the underside of the housing 2 - with respect to the vertical direction z - a suction mouth 8 is formed, which is delimited by a front suction mouth edge 8a and a rear suction mouth edge 8b with respect to the working direction x and further connects to the suction channel 6 arranged above it.

[0047] In A cleaning element 9 is arranged in the suction channel 6 so as to be rotatable about an axis of rotation d running in the transverse direction y. The cleaning element 9 comprises a cleaning roller 10 which is equipped with cleaning means in the form of tufts of bristles 10a and cleaning lips 10b. In the exemplary embodiment shown, the cleaning roller 10 is designed so as to be removable from the housing 2. For driving purposes, the cleaning element 9 additionally has a drive element 11 which can be connected to the cleaning roller 10 and which is mounted in the housing 2 so as to be stationary and rotatable about the axis of rotation d. For connection to the cleaning roller 10, the drive element 11 has a drive mandrel (not shown) which projects into an associated receptacle of the cleaning roller 10.

[0048] 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 chamber 14 is formed, in which the electric drive 12 is mechanically coupled to the cleaning element 9.

[0049] The electric motor 13 is formed with a motor housing 13a, which has a cooling air outlet 13b. According to the invention, the cooling air outlet 13b is fluidly connected to the transmission chamber 14. In the illustrated embodiment, this is achieved by an exhaust air duct 15.

[0050] This is sealingly connected to the motor housing 13a and opens into a wall 14a of the transmission chamber 14.

[0051] How to do this in particular Fig. 3 As can be seen, the housing 13a of the electric motor 13 is arranged entirely within a motor chamber 17 formed in the housing 2. The electric drive 12 comprises a drive wheel 12a arranged in the transmission chamber 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.

[0052] The wall 14a of the transmission chamber 14 further forms a partition 16 to the suction channel 6. The partition 16 has an opening 16b formed with a border 16a, through which the cleaning element 9 protrudes. In the illustrated embodiment, the outermost edge of the cleaning element 9 is formed by the roller body of the cleaning roller 10 in the region of the opening 16b. Between the border 16a and the cleaning roller 10, an annular channel s 2 of between 0.5 mm and 2 mm remains, which fluidically connects the transmission chamber 14 to the suction channel 6.

[0053] In the illustrated embodiment, the electric drive 12 is connected to the drive element 11 of the cleaning roller 9 via its drive wheel 12a, which is rotatable about a drive axis a, by a continuously rotating drive means in the form of a toothed belt 18. For this purpose, part of the drive element 11 is designed as a drive pinion 11a, over which the toothed belt 18 runs. The drive axis a and the rotational axis d are aligned parallel to one another in the transverse direction y and arranged one behind the other with respect to the working direction x. Preferably, the drive axis a is arranged at at least the same height with respect to the vertical direction z.

[0054] The air flow is in the Fig. 3indicated by arrows. The motor chamber 17 has an air intake opening 17a, which connects it to the exterior of the housing 2. The air intake opening 17a opens into a gap between the housing 2 and the intermediate piece 3. At this point, it is concealed on the one hand and protected from the ingress of dirt and accidental covering on the other.

[0055] In the exemplary embodiment shown, the electric motor 13 has a cooling air inlet 13d. This is arranged on the side of the motor housing 13a facing away from the air supply opening 17a. As a result, a cooling air flow entering through the air supply opening 17a initially passes along the outside of the motor housing 13a before entering the interior 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 the motor housing 13a through the cooling air outlet 13b. It is transferred through the exhaust air line 15 into the transmission chamber 14. Due to the pressure drop prevailing during operation, the cooling air flow is finally guided through the annular channel s2 into the suction channel 6, where it is drawn off together with the suction air flow through the suction line 7 in the direction of the suction connection piece 4.

Claims

1. A vacuum cleaner nozzle (1) with a housing (2), with a suction channel (6) formed in the housing (2), with a suction mouth (8), which is formed on an underside of the housing, extends in a transverse direction (y) and adjoins the suction channel (6), with a cleaning element (9) rotatably arranged about an axis of rotation (d) in the suction channel (6), with a transmission chamber (14) arranged next to the suction channel (6) in the transverse direction (y), and with an electric drive (12), which is at least partly arranged in the transmission chamber (14) and which has an electric motor (13), which electric drive is mechanically coupled to the cleaning element (9) in the transmission chamber (14), wherein the electric drive (12) has a cooling air outlet (13b), which is fluidically connected to the transmission chamber (14), 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 that the cooling air outlet (13b) is connected to the transmission chamber (14) by means of a waste air line (15).

2. The vacuum cleaner nozzle (1) according to claim 1, characterized in that the electric drive (12) has a drive wheel (12a) arranged in the transmission chamber (14).

3. The vacuum cleaner nozzle (1) according to claim 2, characterized in that the electric motor (13) is arranged outside of the transmission chamber (14), that the drive wheel (12a) is connected to the electric motor (13) by means of a drive shaft (13c), which runs through a wall (14a) of the transmission chamber (14).

4. The vacuum cleaner nozzle (1) according to claim 3, characterized in that an annular gap (s1) 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).

5. The vacuum cleaner nozzle (1) according to one of claims 1 to 4, characterized in that the waste air line (15) has a line cross section of between 4 mm2 and 30 mm2.

6. The vacuum cleaner nozzle (1) according to one of claims 1 to 5, characterized in that the waste air line (15) is formed as pipeline.

7. The vacuum cleaner nozzle (1) according to one of claims 1 to 6, characterized in that the waste air line (15) is integrated into the housing (2).

8. The vacuum cleaner nozzle (1) according to one of claims 1 to 7, characterized in that the waste air line (15) adjoins the motor housing (13a) in a sealing manner.

9. The vacuum cleaner nozzle (1) according to one of claims 1 to 8, characterized in that the waste air line (15) opens out into a wall (14a) of the transmission chamber (14).

10. The vacuum cleaner nozzle (1) according to one of claims 1 to 9, characterized in that the cleaning element (9) has a cleaning roller (10), which is fitted with cleaning means (10a, 10b), in particular with bristles (10a), and a drive element (11), which can be releasably connected to the cleaning roller (10) and which is coupled to the electric drive (12).

11. The vacuum cleaner nozzle (1) according to claim 10, characterized in that the drive element (11) is mounted on the housing (2) in a stationary manner and so as to be rotatable about the axis of rotation (d).

12. The vacuum cleaner nozzle (1) according to claim 10 or 11, characterized in that the cleaning roller (10) can be removed from the housing (2).

13. The vacuum cleaner nozzle (1) according to one of claims 1 to 12, characterized in that the electric drive (12) and the cleaning element (9) are coupled to one another by means of a gear.

14. The vacuum cleaner nozzle (1) according to one of claims 1 to 12, characterized in that the electric drive (12) and the cleaning roller (9) are coupled by means of a continuously circumferential drive means, in particular a toothed belt (18).

15. The vacuum cleaner nozzle (1) according to one of claims 1 to 14, characterized in that the transmission chamber (14) is separated from the suction channel (6) by means of a dividing wall (16), that the dividing wall (16) has an opening (16b), which is formed with a boundary (16a), through which the cleaning element (9) protrudes and that an annular channel (s2) is formed between the boundary (16a) and the cleaning element (9), in particular the cleaning roller (10).

16. The vacuum cleaner nozzle (1) according to claim 15, characterized in that the annular channel (s2) has a size measured perpendicular to the axis of rotation (d) of between 0.5 mm and 2 mm, in particular between 0.5 mm and 1 mm.

17. The vacuum cleaner nozzle (1) according to one of claims 1 to 16, characterized in that the electric motor (13) is at least partly, preferably completely, arranged in particular with a motor housing (13a) in a motor chamber (17) formed in the housing (2).

18. The vacuum cleaner nozzle (1) according to claim 17, characterized in that the motor chamber (17) has at least one supply air opening (17a).

19. The vacuum cleaner nozzle (1) according to claim 18, characterized in that the supply air opening (17a) is arranged in a region of the motor chamber (17), which, based on the electric motor (13), lies opposite the cooling air inlet (13d).