Underwater cleaner

Abstract

The invention relates to an underwater cleaner (1) with a housing (2) in which a pump 3, in particular battery-operated, with an electric motor (4) and an axial impeller (5) rotatable about a pivot axis (5a) is arranged, with a suction nozzle (6) formed by the housing (2) having a suction opening (8) defining a suction plane (ε) and a flow channel (9) arranged in the housing (2) and accommodating the axial impeller (5), which extends between a channel inlet opening (11) arranged in the region of the suction nozzle (6) and a channel outlet opening (13), wherein a receptacle (24) for a filter device (25) is arranged in the region of the channel outlet opening (13), and wherein the flow axis (9a) of the flow channel (9) is normal to the suction plane (ε) in a first section (10) having the channel inlet opening (11) and parallel to the channel outlet opening (13) in a second section (12) having the channel outlet opening (13). suction plane (ε) is arrangedand wherein the axial impeller (5) is arranged in the first section (10) of the flow channel (9), and wherein a first distance (a) between a reference plane (δ) tangent to a lower channel wall (17) of the second section (12) and normal to the axis of rotation (5a) of the axial impeller (5) and the suction plane (ε) is smaller than the impeller radius (r). A compact underwater cleaner (1) with high suction efficiency can be realized if the reference plane (δ) intersects the axial impeller (5) in at least one region of the impeller blades (18) and at least one impeller blade (18) projects beyond the reference plane (δ) by a defined overhang (c).

Description

[0001] The invention relates to an underwater cleaner, in particular for a swimming pool, comprising a housing in which a pump, in particular a battery-operated pump, is arranged with an electric motor and an axial impeller rotatable about an impeller rotation axis, comprising a suction nozzle formed by the housing with a suction mouth defining a suction plane, and a flow channel arranged in the housing and accommodating the impeller, which extends between a channel inlet opening arranged in the region of the suction nozzle and a channel outlet opening, wherein a receptacle for a filter device is arranged in the region of the channel outlet opening, and wherein the center of flow of the flow channel is arranged normal to the suction plane in a first section having the channel inlet opening and parallel to the suction plane in a second section having the channel outlet opening, and wherein the axial impeller is arranged in the first section of the flow channel,and wherein a first distance between a reference plane tangent to a lower channel wall of the second section normal to the axis of rotation of the axial impeller and the suction plane is smaller than the impeller radius.,

[0002] AT 525 918 B1 discloses an underwater cleaner comprising a housing in which a battery-operated pump with an electric motor and an axial impeller rotatable about a rotational axis is arranged. A suction nozzle is formed integrally with the housing and defines a suction plane. A flow channel runs between an inlet opening located in the area of ​​the suction nozzle and an outlet opening, without any bends and inclined at an angle of approximately 45° to the suction plane.

[0003] EP 3 832 053 A discloses an underwater cleaner with a flow channel that is arranged vertically, i.e. at a right angle to the suction plane, with the outlet from the flow channel being located at the highest point of the housing. A collar-like receptacle for a filter container is provided in the outlet area. The vertical orientation of the flow channel has the disadvantage that, after the impeller drive motor is switched off, dirt particles can fall into the filter device. To prevent backcontamination, specially designed filter devices are required. The impeller is arranged far from the suction plane and close to the outlet opening above the electric motor, which requires relatively high drive power to achieve acceptable suction results. The arrangement of the electric motor in the flow channel on the suction side of the impeller causes relatively high flow losses.A similar battery-operated underwater vacuum cleaner is also known from US 2020 / 0 263 444 A1.

[0004] Furthermore, EP 2 989 270 B1 discloses a handheld swimming pool vacuum with a battery-operated pump and an axial impeller arranged in a flow channel, the axis of rotation of which is perpendicular to the suction plane. The flow channel extends from an inlet opening located in the area of ​​the suction plane and ends in a lateral outlet opening, to which a dirt collection container is connected.

[0005] EP 3 141 675 B1 discloses an underwater cleaner comprising a housing in which a battery-operated pump with an electric motor and an impeller is arranged. The housing has an inlet and an outlet for a flow path. The flow path has a first channel section extending from the first inlet and a second channel section accommodating the impeller. The second channel section is arranged at an angle to the first channel section, with the impeller's rotational axis being arranged at an angle to a normal to the opening cross-section of the inlet.

[0006] US 2005 / 0247613 A1 discloses an underwater vacuum cleaner in which the impeller's rotational axis is inclined to a normal to an inlet cross-sectional area. Adjacent to the inlet opening of the underwater vacuum cleaner is a first channel section with a tapered cross-section, which opens into a suction chamber in which a dirt filter is located. A second channel section extends from this suction chamber, in which a pump with a radial impeller is arranged, the impeller's rotational axis being inclined to a normal to the opening cross-section of the inlet opening. The inlet cross-section of the pump is relatively small. Due to numerous deflections and sharp edges, turbulence occurs, particularly adjacent to the first channel section, which limits the suction power.

[0007] AT 524 846 A4 describes a hand-held underwater cleaner comprising a housing with an impeller driven by an electric motor. The housing has an inlet opening in the bottom area and an outlet opening on a lateral outlet side, with a collecting container receptacle for receiving a collecting container arranged in the area of ​​the outlet opening. A flow channel extends between the inlet opening and the outlet opening, with the axial impeller arranged in the flow channel. The center of flow axis is normal to the suction plane in the area of ​​the inlet opening and parallel to the suction plane in the area of ​​the outlet opening. The distance between a reference plane tangent to a lower channel wall of the flow channel in the area of ​​the outlet opening, normal to the axis of rotation of the axial impeller, and the suction plane is smaller than the impeller radius. AT 513 827 A4 discloses a similar underwater cleaner.

[0008] The known underwater cleaners usually have a relatively high construction height with a high center of gravity, which has a negative impact on the size, stability and cleaning effect.

[0009] The object of the invention is to provide a compact underwater cleaner with high suction power.

[0010] According to the invention, this object is achieved in an underwater cleaner of the type mentioned at the outset in that the reference plane intersects the axial impeller in at least one region of the rotor blades and at least one rotor blade projects beyond the reference plane by a defined projection.

[0011] The suction nozzle is formed by the housing of the underwater cleaner. A circumferential edge of the suction nozzle forms a suction mouth and defines a suction plane, which, during operation, is oriented approximately parallel to the surface to be cleaned.

[0012] Because the first distance is smaller than the impeller radius, the underwater cleaner can be designed very flat and compact. This, in turn, allows for a relatively low center of gravity—close to the surface to be cleaned. The underwater cleaner thus stands very stable and tilt-proof on the surface to be cleaned, without the optimal position of the suction nozzle in relation to the surface to be cleaned being altered by tilting movements. This has a beneficial effect on the cleaning effect.

[0013] In a particularly stable and tip-proof version of the invention, the first distance is a maximum of 75%, preferably a maximum of 72%, of the impeller radius. This allows for excellent cleaning results with a compact design.

[0014] The underwater cleaner has a front side arranged in the direction of movement and a rear side facing away from the direction of movement.

[0015] The channel outlet opening is located opposite to the direction of movement, i.e. on the back of the underwater cleaner.

[0016] A low construction of the underwater cleaner can be achieved if the underwater cleaner in the second section - in particular in the area of ​​the channel outlet opening - has a substantially rectangular cross-section with a height measured normal to the suction plane and a width measured parallel to the suction plane, wherein the height is preferably a maximum of 25%, particularly preferably a maximum of 22%, of the width.

[0017] In a particularly flat embodiment of the invention, a second distance between the reference plane and the channel inlet of the flow channel is a maximum of 50% of the impeller radius. This allows the first section of the flow channel to be kept particularly short. The axial impeller can thus be arranged in the area of ​​the channel inlet of the flow channel, i.e., particularly close to the suction nozzle. This enables a high suction effect, preventing sucked-in particles from being thrown back toward the suction plane.

[0018] Due to the extremely short first section, the axial impeller is also positioned near the reference plane. The impeller blades project beyond the reference plane by a slight, defined overhang. This overhang is preferably approximately 10% ± 2% of the impeller radius. This allows the centrifugal force of the impeller to be utilized, and stray dirt particles that are not entrained by the main flow are thrown into the second section of the flow channel at the impeller outlet. This improves the cleaning effect.

[0019] In one embodiment of the invention, the flow channel, at the transition from the first section to the second section, has an outer curved region with a first radius of curvature that is smaller than the impeller radius, preferably smaller than half the impeller radius. In particular, the first radius of curvature can be a maximum of 25%, preferably a maximum of 20%, of the impeller radius. Surprisingly, it has been shown that a relatively small first radius of curvature prevents dirt particles from being thrown back, thus increasing the cleaning effect of the underwater cleaner.

[0020] To achieve a high suction effect, it is advantageous if the flow channel upstream of the axial impeller has a cylindrical or slightly conical suction jacket. The suction jacket extends from the channel inlet opening.

[0021] The suction nozzle with the suction mouth is arranged upstream of the channel inlet opening. In one embodiment of the invention, the suction nozzle has a non-circular layout with a simply symmetrical suction mouth. Numerous tests have shown that the suction effect can be improved if the suction mouth is essentially designed as a two-winged nozzle, with a lateral wing area arranged on either side of a central area. The central area is located primarily in the rear area of ​​the underwater cleaner and is essentially formed by a bulge in the shape of the suction mouth.

[0022] The suction mouth has a depth extension measured in the direction of movement of the underwater cleaner and a width extension measured normal to the depth extension, whereby the greatest depth extension measured in the central area is at least 50%, preferably at least 55% of the greatest width extension.

[0023] A variant of the invention provides that the central region has a second radius of curvature that is greater than the impeller radius. The blade regions advantageously each have a third radius of curvature that is smaller than the second radius of curvature of the central region, wherein the third radius of curvature is preferably a maximum of 1 / 2, particularly preferably a maximum of 1 / 3, and in particular a maximum of 1 / 4 of the second radius of curvature.

[0024] Between the two lateral wing areas, the suction mouth advantageously has a fourth radius of curvature on the front side, which is at least twice, preferably at least three times, as large as the second radius of curvature.

[0025] Furthermore, the suction mouth may have a convex portion between the central region and each lateral wing region, wherein the convex portion forms a fifth radius of curvature, which preferably corresponds to the second radius of curvature ± 20%.

[0026] The described shape of the suction mouth enables a strong and even suction effect across the entire width.

[0027] The invention will be explained in more detail below with reference to the non-limiting embodiment shown in the figures, which schematically show: Fig. 1 an underwater cleaner according to the invention in a section along the line II in Fig. 2 , Fig. 3 oder Fig. 4 ; Fig. 2 the underwater cleaner in a bottom view; Fig. 3 the underwater cleaner in a top view; and Fig. 4 the underwater cleaner in a view from the rear.

[0028] The Fig. 1 bis Fig. 4 show an underwater cleaner 1 for cleaning a swimming pool. The underwater cleaner 1 has a housing 2 in which a battery-operated pump 3 with an electric motor 4 and an axial impeller 5 rotatable about a rotation axis 5a is arranged. Reference numeral 28 designates a battery compartment for accommodating, for example, a rechargeable battery 29. 30 designates a housing cover that covers the electric motor 4 and the battery compartment 28 in a liquid-tight manner. The housing 2 is essentially simply symmetrical with respect to a plane of symmetry σ, which is formed by a plateau of the underwater cleaner 1 through the rotation axis 5a of the axial impeller 5.

[0029] On the underside U of the underwater cleaner 1, which faces the surface to be cleaned, a suction nozzle 6 formed by the housing 2 is arranged. A circumferential edge 7 of the suction nozzle 6 forms a suction mouth 8 and defines a suction plane ε, which is oriented approximately parallel to the surface to be cleaned during operation. At the edge of the circumferential edge 7 of the suction mouth 8, several brushes 26 are arranged, which enable the underwater cleaner 1 to glide effortlessly along the surface. The holders 27, which are designed in one piece with the housing 2 (see Fig. 2 ) arranged brushes 26 define an optimal distance of the suction mouth 8 to the surface to be cleaned and can be used to support the cleaning effect.

[0030] The underwater cleaner 1 has a front side F arranged in the direction of movement and a rear side R facing away from the direction of movement.

[0031] A flow channel 9 is arranged in the housing 2, extending in a 90° bend 14 between a first section 10 with a channel inlet opening 11 and a second section 12 with a channel outlet opening 13. The 90° bend 14 has an inner bend region 15 and an outer bend region 16.

[0032] The axial impeller 5 is arranged in the first section 10 of the flow channel 9, which is perpendicular to the suction plane ε, and whose axis of rotation 5a is arranged perpendicular to the suction plane ε and parallel to the center flow axis 9a of the flow channel 9 in the first section 10. The axis of rotation 5a is arranged in the plane of symmetry σ of the housing 2.

[0033] At the end of the second section 12 of the flow channel 9, which is arranged perpendicular to the rotation axis 5a and parallel to the suction plane ε, a flange-like receptacle 24 for a filter device 25—for example, a filter bag—is arranged in the region of the channel outlet opening 13. The center flow axis 9a of the flow channel 9 is arranged perpendicular to the suction plane ε in the first section 10 having the channel inlet opening 11 and parallel to the suction plane ε in the second section 12 having the channel outlet opening 13.

[0034] The channel outlet opening 13 is arranged opposite to the direction of movement P, i.e. on the rear side R of the underwater cleaner 1.

[0035] Reference symbol δ denotes a reference plane which is tangent to the lower channel wall 17 of the second section 12 in the region of the inner arc region 15.

[0036] A first distance a is formed between the reference plane δ and the suction plane ε. The first distance a is smaller than the impeller radius r of the axial impeller 5. In the exemplary embodiment, the first distance a is a maximum of 80%, in particular a maximum of 75% of the impeller radius r, for example a maximum of 72% of the impeller radius r.

[0037] This enables a very flat and compact design and a low arrangement of the center of gravity of the underwater cleaner 1. The underwater cleaner 1 is therefore very stable and tip-proof on the surface to be cleaned.

[0038] The underwater cleaner 1 has in the second section 12 - particularly in the area of ​​the channel outlet opening 13 - a substantially rectangular cross-section with a height H measured normal to the suction plane ε and a width B measured parallel to the suction plane ε ( Fig. 4 ). The height H is a maximum of 25%, for example a maximum of 22%, of the width b. This allows for a low design of the underwater cleaner 1.

[0039] One in Fig. 1 The apparent second distance b between the reference plane δ and the channel inlet opening 11 of the flow channel 9 is a maximum of 50% of the impeller radius r. Thus, the first section 10 of the flow channel 9 can be kept particularly short, enabling a particularly flat design. The axial impeller 5 is thus arranged particularly close to the suction nozzle 6 in the area of ​​the channel inlet opening 11 of the flow channel 9. This enables a high suction effect, preventing sucked-in particles from being thrown back toward the suction plane ε.

[0040] Due to the extremely short first section 10, the axial impeller 5 is also arranged in the region of the reference plane δ. In particular, the axial impeller 5 is arranged such that the reference plane δ intersects the axial impeller 5 in at least one region of the rotor blades 18 of the axial impeller 5. The rotor blades 18 of the axial impeller 5 thus project beyond the reference plane δ by a slight, defined projection c, which in the exemplary embodiment amounts to approximately 10% ± 2% of the impeller radius r. In this way, the centrifugal force of the axial impeller 5 can be utilized, and stray dirt particles that are not entrained by the main flow can be thrown at the impeller outlet into the second section 12 of the flow channel 9. This enables an improvement in the cleaning effect.

[0041] In the outer curved area 16 at the transition between the first section 10 and the second section 11, the flow channel 9 has a first radius of curvature k 1 which is smaller than the impeller radius r, for example smaller than half the impeller radius r ( Fig. 1 In the exemplary embodiment, the first radius of curvature k 1 is a maximum of 25%, for example a maximum of 20%, of the impeller radius r. This prevents dirt particles from being thrown back and thus increases the cleaning effect of the underwater cleaner 1.

[0042] The flow channel 9 has, upstream of the axial impeller 5, a suction jacket 19 that is at least partially cylindrical or slightly conical. The suction jacket 19 extends from the suction nozzle 6 via the channel inlet opening 11.

[0043] Upstream of the channel inlet opening 11, the suction nozzle 6 with the suction mouth 8 is arranged. The suction nozzle 6 has a plan view deviating from a circular basic shape 20 with a second radius of curvature k 2 and is designed essentially symmetrically with respect to the plane of symmetry σ of the housing 2. The suction mouth 8 is essentially designed with two wings and has an essentially circular central region 21 and two adjoining lateral wing regions 22 on either side of the central region 21. Wing regions 22 are understood here to be more or less pronounced bulges with respect to the circular basic shape 20 of the central region 21, which in Fig. 2is indicated by dashed lines. The central region 21 forms a substantially cylindrical bulge of the housing 2 in the region of the rear side R of the underwater cleaner 1. The central region 21 is understood as a parallel projection of the suction jacket 19 in the region of the channel inlet opening 11 onto the suction plane ε. The lateral wing regions 22 are arranged outside the parallel projection of the channel inlet opening 11 onto the suction plane ε.

[0044] The shape of the suction mouth 8 can also be described as triangular or roof-shaped - each with rounded corners.

[0045] The suction mouth 8 has a depth extension T measured in the direction of movement P of the underwater cleaner 1 and a width extension W measured perpendicular to the depth extension. The greatest depth extension T measured in the region of the central region 21 is at least 50%, for example at least 55%, of the greatest width extension W.

[0046] The central region 21 is designed with the second radius of curvature k 2 of the circular basic shape 20, which is greater than the impeller radius r. The lateral wing regions 22 each have a third radius of curvature k 3 , which is smaller than the second radius of curvature k 2 of the central region 21. The third radius of curvature k 3 is a maximum of ½, in particular a maximum of ⅓, for example a maximum of ¼ of the second radius of curvature k 2 .

[0047] Between the two lateral wing regions 22, the suction mouth 8 on the front side F has a fourth radius of curvature k 4 , which is at least twice, for example at least three times as large as the second radius of curvature k 2 .

[0048] Between the central region 21 and each lateral wing region 22, the suction mouth 8 has a convex section 23. The convex section 23 forms a fifth radius of curvature k 5 , which corresponds, for example, to the second radius of curvature k 2 ± 20%.

[0049] The described shape of the suction mouth 8 enables a strong and uniform suction effect of the underwater cleaner 1 across the width W.

Claims

1. Underwater cleaner (1), in particular for a swimming pool, with a housing (2) in which a pump 3, in particular a battery-operated pump, is arranged, with an electric motor (4) and an axial impeller (5) rotatable about a rotational axis (5a), with a suction nozzle (6) formed by the housing (2) with a suction mouth (8) defining a suction plane (ε), and with a flow channel (9) arranged in the housing (2) and accommodating the axial impeller (5), which extends between a channel inlet opening (11) arranged in the region of the suction nozzle (6) and a channel outlet opening (13), wherein a receptacle (24) for a filter device (25) is arranged in the region of the channel outlet opening (13), and wherein the flow center axis (9a) of the flow channel (9) is perpendicular to the suction plane (ε) in a first section (10) having the channel inlet opening (11) and in a second section having the channel outlet opening (13) Section (12) is arranged parallel to the suction plane (ε),and wherein the axial impeller (5) is arranged in the first section (10) of the flow channel (9), and wherein a first distance (a) between a reference plane (δ) tangent to a lower channel wall (17) of the second section (12) normal to the axis of rotation (5a) of the axial impeller (5) and the suction plane (ε) is smaller than the impeller radius (r), , characterized in that the reference plane (δ) intersects the axial impeller (5) in at least one region of the rotor blades (18) and at least one rotor blade (18) projects beyond the reference plane (δ) by a defined projection (c).

2. Underwater cleaner (1) according to claim 1, characterized in that the first distance (a) is a maximum of 80%, preferably a maximum of 75%, particularly preferably a maximum of 72%, of the impeller radius (r).

3. Underwater cleaner (1) according to claim 1 or 2, characterized in thata second distance (b) between the reference plane (δ) and the channel inlet opening (11) of the flow channel (9) is a maximum of 50%, preferably a maximum of 40%, particularly preferably a maximum of 37% of the impeller radius (r).

4. Underwater cleaner (1) according to one of claims 1 to 3, characterized in that the axial impeller (5) is arranged in the region of the channel inlet opening (11) of the flow channel (9).

5. Underwater cleaner (1) according to one of claims 1 to 4, characterized in that the axial impeller (5) is arranged in the area of ​​the reference plane (δ).

6. Underwater cleaner (1) according to one of claims 1 to 5, characterized in that the projection (c) is approximately 10% ± 2% of the impeller radius (r).

7. Underwater cleaner (1) according to one of claims 1 to 6, characterized in thatthe flow channel (9) in the transition between the first section (10) and the second section (12) has an outer curved region (16) with a first radius of curvature (k1) which is smaller than the impeller radius (r), preferably smaller than half the impeller radius (r).

8. Underwater cleaner (1) according to claim 7, characterized in that the first radius of curvature (k1) is a maximum of 25%, preferably a maximum of 20%, of the impeller radius (r).

9. Underwater cleaner (1) according to one of claims 1 to 8, characterized in that the underwater cleaner (1) in the second section (12) - in particular in the region of the channel outlet opening (13) - has a substantially rectangular cross-section with a height (H) measured normal to the suction plane (ε) and a width (B) measured parallel to the suction plane (ε), wherein the height (H) is preferably a maximum of 25%, particularly preferably a maximum of 22%, of the width (B).

10. Underwater cleaner (1) according to one of claims 1 to 9, characterized in that the suction nozzle (6) has a ground plan deviating from a circular basic shape (20) with a simply symmetrical suction mouth (8).

11. Underwater cleaner (1) according to claim 10, characterized in that the suction mouth (8) is essentially designed with two wings, with a lateral wing region (22) being arranged on each side of a central region (21), with the suction mouth (8) preferably having a depth extension (T) measured in the direction of movement (P) of the underwater cleaner (1) and a width extension (W) measured normal to the depth extension (T), with the greatest depth extension (T) measured in the central region (21) being at least 50%, preferably at least 55% of the greatest width extension (W).

12. Underwater cleaner (1) according to claim 10, characterized in thatthe central region (21) has a second radius of curvature (k2) which is greater than the impeller radius (r).

13. Underwater cleaner (1) according to claim 11 or 12, characterized in that the lateral wing regions (22) each have a third radius of curvature (k3) which is smaller than the second radius of curvature (k2) of the central region (21), wherein the third radius of curvature (k3) is preferably a maximum of ½, particularly preferably a maximum of ⅓, in particular a maximum of ¼ of the second radius of curvature (k2).

14. Underwater cleaner (1) according to one of claims 11 to 13, characterized in that a fourth radius of curvature (k4) is formed between the two wing regions (22), which is at least twice, preferably at least three times as large as the second radius of curvature (K2).

15. Underwater cleaner (1) according to one of claims 11 to 14, characterized in thatbetween the central region (21) and each wing region (22) the suction mouth (8) has a convex section (23), wherein the convex section (23) forms a fifth radius of curvature (k5) which preferably corresponds to the second radius of curvature (k2) ±20%.

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