UNDERWATER CLEANERS

Description

[0001] The invention relates to an underwater cleaner, particularly for a swimming pool, comprising a housing in which a pump, particularly battery-operated, with an electric motor and an axial impeller rotatable about an impeller axis is arranged, 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 flow axis 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 and normal to the axis of rotation of the axial impeller and the suction plane is smaller than the impeller radius.

[0002] From AT 525 918 B1, an underwater cleaner is known with a housing in which a battery-operated pump with an electric motor and an axially rotatable impeller is arranged. A suction nozzle is integrally formed 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 bends and inclined at an angle of approximately 45° to the suction plane.

[0003] From EP 3 832 053 A, an underwater cleaner with a flow channel is known which is arranged vertically, i.e., at a right angle to the suction plane, with the outlet from the flow channel located at the highest point of the housing. A collar-like receptacle for a filter container is provided in the area of ​​the outlet. The vertical orientation of the flow channel has the disadvantage that, after the drive motor for the impeller is switched off, dirt particles falling into the filter device can become re-contaminated. To prevent re-contaminated filter devices, specially designed filter devices are required. The impeller is located far from the suction plane and near the outlet opening above the electric motor, which necessitates 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-powered 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 cleaner 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 region of the suction plane and terminates in a lateral outlet opening to which a collection container for dirt is connected.

[0005] From EP 3 141 675 B1, an underwater cleaner is known with a housing in which a battery-operated pump with an electric motor and an impeller is arranged, the housing having an inlet opening and an outlet opening for a flow path. The flow path has a first channel section extending from the first inlet opening and a second channel section accommodating the impeller. The second channel section is inclined relative to the first channel section, with the impeller axis of rotation inclined to a normal to the cross-section of the inlet opening.

[0006] US Patent 2005 / 0247613 A1 discloses an underwater vacuum cleaner in which the impeller axis of rotation is inclined to a normal to an inlet cross-sectional area. Following the inlet opening of the underwater vacuum cleaner, a first channel section with a tapered cross-section is arranged, which leads into a suction chamber containing a dirt filter. From this suction chamber, a second channel section extends, in which a pump with a radial impeller is arranged. The impeller axis of rotation is inclined to a normal to the opening cross-section of the inlet opening. The inlet cross-section to the pump is relatively small. Due to numerous bends and sharp edges, turbulence occurs, particularly downstream of the first channel section, which restricts the suction performance.

[0007] AT 524 846 A4 describes a handheld underwater cleaner with a housing containing an impeller driven by an electric motor. The housing has an inlet opening in the base and an outlet opening on a side, with a collection container receptacle located in the outlet area. A flow channel extends between the inlet and outlet openings, with the axial impeller located within the flow channel. The 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 and normal to the axis of rotation of the axial impeller, and the suction plane, is less than the impeller radius. AT 513 827 A4 discloses a similar underwater cleaner.

[0008] Most well-known underwater cleaners have a relatively large height and a high center of gravity, which negatively affects their size, stability, and cleaning performance.

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

[0010] According to the invention, this problem is solved in an underwater cleaner of the type mentioned above by the fact that the reference plane intersects the axial impeller in at least one area of ​​the impeller blades and at least one impeller blade projects beyond the reference plane by a defined overhang.

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

[0012] Because the initial distance is smaller than the impeller radius, the underwater cleaner can be built very flat and compact. This, in turn, allows for a relatively low center of gravity – close to the surface being cleaned. As a result, the underwater cleaner stands very stably and securely on the surface being cleaned, without any tilting movements altering the optimal position of the suction nozzle relative to the surface. This has a beneficial effect on the cleaning performance.

[0013] In a particularly stable and tip-resistant embodiment 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 to be achieved with a compact design.

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

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

[0016] A low-profile design of the underwater cleaner can be achieved if the underwater cleaner in the second section - particularly 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 preferably the height is a maximum of 25%, and 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 opening 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 positioned in the region of the channel inlet opening of the flow channel, i.e., very close to the suction nozzle. This enables a high suction effect, preventing aspirated particles from being flung back towards the suction plane.

[0018] Due to the extremely short first section, the axial impeller is also positioned within the reference plane. The impeller blades extend slightly, but with a defined, overhang above the reference plane. This overhang is preferably approximately 10% ± 2% of the impeller radius. This allows the centrifugal force of the impeller to be utilized, flinging away dirt particles that are not carried along by the main flow 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 arc 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 found that a relatively small first radius of curvature prevents the dirt particles from being flung back and thus increases 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] Upstream of the channel inlet opening, the suction nozzle with the suction opening is arranged. In one embodiment of the invention, the suction nozzle has a non-circular plan shape with a simply symmetrical suction opening. Numerous tests have shown that the suction effect can be improved if the suction opening is essentially two-winged, with a lateral wing section arranged on either side of a central area. The central area is located primarily on the rear side of the underwater cleaner and is essentially formed by a bulge in the shape of the suction opening.

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

[0023] One embodiment of the invention provides that the central region has a second radius of curvature which is larger than the impeller radius. Advantageously, the blade regions each have a third radius of curvature which is smaller than the second radius of curvature of the central region, wherein the third radius of curvature is preferably at most ½, more preferably at most ⅓, and particularly at most ¼ 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 can have a convex section between the central area and each lateral wing area, wherein the convex section 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 uniform suction effect across its width.

[0027] The invention will be explained in more detail below with reference to the non-restrictive embodiment shown in the figures. These schematically show: Fig. 1 shows an underwater cleaner according to the invention in a section along line II. 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 rear view.

[0028] The Fig. 1 bis Fig. 4 Figure 1 shows 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 pivot axis 5a is arranged. Reference numeral 28 designates a battery compartment for accommodating, for example, a rechargeable battery 29. Reference numeral 30 designates a housing cover that provides a liquid-tight seal over the electric motor 4 and the battery compartment 28. The housing 2 is essentially simply symmetrical with respect to a plane of symmetry σ, which is formed by a raised surface of the underwater cleaner 1 through the pivot axis 5a of the axial impeller 5.

[0029] A suction nozzle 6, formed by the housing 2, is arranged on the underside U of the underwater cleaner 1, which faces the surface to be cleaned. A circumferential edge 7 of the suction nozzle 6 forms a suction opening 8 and defines a suction plane ε, which is oriented approximately parallel to the surface to be cleaned during operation. Several brushes 26 are arranged at the edge of the circumferential edge 7 of the suction opening 8, which enable the underwater cleaner 1 to glide effortlessly along the surface. The holders 27, which are integrally formed with the housing 2 (see Fig. 2 The brushes 26 arranged define an optimal distance between the suction nozzle 8 and 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 back side R facing away from the direction of movement.

[0031] A flow channel 9 is arranged in the housing 2, extending in a 90° arc 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° arc 14 has an inner arc region 15 and an outer arc region 16.

[0032] The axial impeller 5 is arranged in the first section 10 of the flow channel 9, which is normal to the suction plane ε. Its axis of rotation 5a is normal to the suction plane ε and parallel to the flow axis 9a of the flow channel 9 in the first section 10. The axis of rotation 5a is located 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 axis of rotation 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 flow axis 9a of the flow channel 9 is arranged perpendicular to the suction plane ε in the first section 10, which has the channel inlet opening 11, and parallel to the suction plane ε in the second section 12, which has the channel outlet opening 13.

[0034] The channel outlet opening 13 is located opposite the direction of movement P, i.e. on the back 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 area 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 at most 80%, in particular at most 75%, of the impeller radius r, for example at most 72% of the impeller radius r.

[0037] This allows for a very flat and compact design and a low center of gravity for 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 - especially 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-profile design of the underwater cleaner 1.

[0039] A 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. This allows the first section 10 of the flow channel 9 to be kept particularly short, enabling a particularly flat design. The axial impeller 5 is thus positioned very close to the suction nozzle 6 in the region of the channel inlet opening 11 of the flow channel 9. This ensures a high suction effect, preventing aspirated particles from being thrown back towards the suction plane ε.

[0040] Due to the extremely short first section 10, the axial impeller 5 is also positioned within 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 impeller blades 18. The impeller blades 18 thus project beyond the reference plane δ by a slight, defined overhang c, which in the exemplary embodiment is 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 carried along by the main flow can be flung at the impeller outlet into the second section 12 of the flow channel 9. This improves the cleaning effect.

[0041] In the outer arc region 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 a suction jacket 19 that is at least partially cylindrical or slightly conical upstream of the axial impeller 5. 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 that deviates from a circular basic shape 20 with a second radius of curvature k2 and is essentially symmetrical with respect to the plane of symmetry σ of the housing 2. The suction mouth 8 is essentially two-winged and has an essentially circular central area 21 and two adjoining lateral wing areas 22 on both sides of the central area 21. Wing areas 22 are understood here to be more or less pronounced bulges with respect to the circular basic shape 20 of the central area 21, which in Fig. 2The central area 21 is indicated by dashed lines. It forms a substantially cylindrical bulge in the housing 2 in the area of ​​the rear side R of the underwater cleaner 1. The central area 21 is understood as a parallel projection of the suction jacket 19 in the area of ​​the channel inlet opening 11 onto the suction plane ε. The lateral wing areas 22 are arranged outside the parallel projection of the channel inlet opening 11 onto the suction plane ε.

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

[0045] The suction nozzle 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 maximum depth extension T measured in the area of ​​the central region 21 is at least 50%, for example at least 55%, of the maximum width extension W.

[0046] The central area 21 is designed with the second radius of curvature k 2 of the circular basic shape 20, which is larger than the impeller radius r. The lateral wing areas 22 each have a third radius of curvature k 3, which is smaller than the second radius of curvature k 2 of the central area 21. The third radius of curvature k 3 is at most, in particular at most ⅓, for example at most 1 / 4 of the second radius of curvature k 2.

[0047] Between the two lateral wing areas 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 across the width W of the underwater cleaner 1.

Claims

1. Underwater cleaner (1), in particular for a swimming pool, having a housing (2), in which a pump (3), in particular a battery-operated pump, with an electric motor (4) and an axial impeller (5) rotatable about an axis of rotation (5a) is arranged, having a suction nozzle (6) formed by the housing (2) with a suction mouth (8) defining a suction plane (ε) and a flow channel (9) which is arranged in the housing (2), accommodates the axial impeller (5) and 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 arranged perpendicular to the suction plane (ε) in a first section (10) having the channel inlet opening (11) and parallel to the suction plane (ε) in a second section (12) having the channel outlet opening (13), 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), characterised in that 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 projection (c).

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

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

4. Underwater cleaner (1) according to one of claims 1 to 3, characterised 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, characterised in that the axial impeller (5) is arranged in the region of the reference plane (δ).

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

7. Underwater cleaner (1) according to one of claims 1 to 6, characterised in that the flow channel (9) has, in the transition between the first section (10) and the second section (12), an outer bend area (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, characterised in that the first radius of curvature (k1) is at most 25%, preferably at most 20%, of the impeller radius (r).

9. Underwater cleaner (1) according to one of claims 1 to 8, characterised in that the underwater cleaner (1) in the second section (12) - in particular in the region of the channel outlet opening (13) - has an essentially 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 at most 25%, particularly preferably at most 22%, of the width (B).

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

11. Underwater cleaner (1) according to claim 10, characterised in that the suction mouth (8) is essentially two-winged, wherein a lateral wing area (22) is arranged on either side of a central area (21), wherein preferably 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 normal to the depth extension (T), wherein the largest depth extension (T) measured in the central area (21) is at least 50%, preferably at least 55%, of the largest width extension (W).

12. Underwater cleaner (1) according to claim 11, characterised in that the central area (21) comprises a second radius of curvature (k2) which is larger than the impeller radius (r).

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

14. Underwater cleaner (1) according to one of claims 11 to 13, characterised in that a fourth radius of curvature (k4) is formed between the two wing areas (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, characterised in that between the central area (21) and each wing area (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%.