UNDERWATER CLEANER

Abstract

The invention relates to an underwater cleaner having a housing in which a pump, in particular a battery-operated pump, with an electric motor and an axial impeller rotatable about an axis of rotation is arranged, having a suction nozzle formed by the housing with a suction mouth defining a suction plane and a flow channel which is arranged in the housing accommodates the axial impeller and 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 center axis of the flow channel is arranged perpendicular 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.

Description

The invention relates to an underwater cleaner, in particular for a swimming pool, having a housing in which a pump, in particular a battery-operated pump, with an electric motor and an axial impeller rotatable about an impeller axis of rotation is arranged, having a suction nozzle formed by the housing with a suction mouth defining a suction plane and a flow channel which is arranged in the housing, accommodates the impeller and 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 center axis of the flow channel is arranged perpendicular 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.

AT 525 918 B1 discloses an underwater cleaner having a housing in which a battery-operated pump with an electric motor and an axial impeller that can rotate about an axis of rotation is arranged. A suction nozzle is formed integrally with the housing and defines a suction plane. A flow channel without bends and inclined at an angle of approximately 45° to the suction plane extends between an inlet opening arranged in the area of the suction nozzle and an outlet opening.

EP 3 832 053 A describes an underwater cleaner having a flow channel which is arranged vertically, i.e. at a right angle to the suction plane, wherein the outlet from the flow channel is 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 alignment of the flow channel has the disadvantage that after the drive motor for the impeller has been switched off, dirt particles falling from the filter device can cause recontamination. Specially designed filter devices are required to prevent back-soiling. The impeller is located far from the suction plane and close to the outlet opening above the electric motor, which means that relatively high drive power is required 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.

Furthermore, EP 2 989 270 B1 describes a hand-operated swimming pool vacuum cleaner having a battery-operated pump with an axial impeller arranged in a flow channel, the axis of rotation of which is arranged perpendicular to the suction plane. The flow channel starts from an inlet opening arranged in the area of the suction plane and ends in a lateral outlet opening, to which a collecting container for dirt is connected.

An underwater cleaner with a housing in which a battery-operated pump with an electric motor and an impeller is arranged is known from EP 3 141 675 B1, wherein the housing has 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 arranged inclined to the first channel section, wherein the impeller axis of rotation is arranged inclined to a normal to the opening cross-section of the inlet opening.

US 2005/0247613 A1 discloses an underwater vacuum cleaner in which the impeller axis of rotation is arranged inclined to a normal to an inlet cross-sectional area. A first channel section with a tapering cross-section is arranged adjacent to the inlet opening of the underwater vacuum cleaner, which opens into a suction chamber in which a dirt filter is arranged. A second channel section extends from this suction chamber, in which a pump with a radial impeller is arranged, the impeller axis of rotation of which is inclined to a normal to the opening cross-section of the inlet opening. The inlet cross-section into the pump is of a relatively small dimension. Due to numerous deflections and sharp edges, turbulence occurs, particularly downstream of the first channel section, which limits the suction capacity.

AT 524 846 A4 describes a hand-held underwater cleaner having a housing with an impeller that can be driven by an electric motor. The housing has an inlet opening in the base area and an outlet opening on a lateral outlet side, wherein a collecting container holder for receiving a collecting container is arranged in the area of the outlet opening. A flow channel extends between the inlet opening and the outlet opening, wherein the axial impeller is arranged in the flow channel. The flow center axis is perpendicular 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 normal to the axis of rotation of the axial impeller and the suction plane, which is tangent to a lower channel wall of the flow channel in the area of the outlet opening, is smaller than the impeller radius. AT 513 827 A4 discloses a similar underwater cleaner.

The known underwater cleaners usually have a relatively high height with a high center of gravity, which has a detrimental effect on the size, stability and cleaning effect.

It is the object of the invention to provide a compact underwater cleaner with a high suction effect.

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

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 is oriented approximately parallel to the surface to be cleaned during operation.

The fact that the first distance is smaller than the impeller radius means that the underwater cleaner can be built very flat and compact. This in turn enables a relatively low—i.e. close to the surface to be cleaned—arrangement of the center of gravity of the underwater cleaner. The underwater cleaner is therefore very stable and tilt-proof on the surface to be cleaned without the optimum position of the suction mouth in relation to the surface to be cleaned being changed by tilting movements. This has a beneficial effect on the cleaning effect.

In a particularly stable and tilt-resistant embodiment of the invention, it is provided that the first distance is at most 75%, preferably at most 72%, of the impeller radius. This allows excellent cleaning results to be achieved with a compact design.

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

The channel outlet opening is arranged against the direction of movement, i.e. at the rear of the underwater cleaner.

A low construction of the underwater cleaner can be achieved if the underwater cleaner in the second section—in particular in the region of the channel outlet opening—has an essentially 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 at most 25%, particularly preferably at most 22%, of the width.

In a particularly flat embodiment variant of the invention, it is provided that a second distance between the reference plane and the channel inlet opening of the flow channel is at most 50% of the impeller radius. This means that the first section of the flow channel can be kept particularly short. The axial impeller can thus be arranged in the area of the channel inlet opening of the flow channel, i.e. particularly close to the suction nozzle. This enables a high suction effect, which prevents sucked-in particles from being thrown back towards the suction plane.

Due to the extremely short first section, the axial impeller is also arranged in the region of the reference plane. The impeller blades protrude beyond the reference plane by a slight, defined projection. The projection is preferably about 10%±2% of the impeller radius. In this way, the centrifugal effect of the impeller can be utilized and stray dirt particles that are not entrained by the main flow can be thrown into the second section of the flow channel at the impeller outlet. This improves the cleaning effect.

In one embodiment variant of the invention, it is provided that the flow channel at the transition from the first section to the second section has an outer bend area with a first radius of curvature which is smaller than the impeller radius, preferably smaller than half the impeller radius. In particular, the first radius of curvature can be at most 25%, preferably at most 20%, of the impeller radius. Surprisingly, it has been shown that a relatively small first radius of curvature prevents the dirt particles from being thrown back and thus increases the cleaning effect of the underwater cleaner.

In order 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.

The suction nozzle with the suction mouth is arranged upstream of the channel inlet opening. In one embodiment variant of the invention, it is provided that the suction nozzle has a layout deviating from a circular shape with a single-symmetrical suction mouth. Numerous tests have shown that the suction effect can be improved if the suction mouth is essentially two-winged, wherein a lateral wing area is arranged on either side of a central area. The central area is located primarily in the area of the rear side of the underwater cleaner and is essentially formed by a bulge in the shape of the suction mouth.

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, wherein the largest depth extension measured in the central area is at least 50%, preferably at least 55%, of the largest width extension.

One embodiment variant according to the invention provides that the central area comprises a second radius of curvature which is larger than the impeller radius. The wing areas each advantageously have a third radius of curvature, which is smaller than the second radius of curvature of the central area, wherein the third radius of curvature is preferably at most ½, particularly preferably at most ⅓, especially at most ¼ of the second radius of curvature.

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.

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%.

The described shape of the suction mouth enables a strong and uniform suction effect across the width.

The invention is explained in more detail below with reference to the non-limiting embodiment variant shown in the figures, which show schematically:

FIG. 1 shows a sectional view of an underwater cleaner according to the invention as shown in line I-I in FIG. 2, FIG. 3 or FIG. 4;

FIG. 2 shows the underwater cleaner from below;

FIG. 3 shows a top view of the underwater cleaner; and

FIG. 4 shows a view of the underwater cleaner from the rear.

FIG. 1 to 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 an axis of rotation 5a is arranged. A battery compartment for accommodating a rechargeable battery 29, for example, is indicated by reference sign 28. A housing cover that covers the electric motor 4 and the battery compartment 28 upwards in a liquid-tight manner is designated by 30. The housing 2 is essentially simply symmetrical in relation to a symmetry plane σ, which is formed by a vertical plane of the underwater cleaner 1 through the axis of rotation 5a of the axial impeller 5.

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 mouth 8 and defines a suction plane E, 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 mouth 8, which allow the underwater cleaner 1 to glide effortlessly along the surface. The brushes 26, which are arranged in holders 27 (see FIG. 2) made in one piece with the housing 2, define an optimum distance between the suction mouth 8 and the surface to be cleaned and can be used to support the cleaning effect.

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.

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

The axial impeller 5 is arranged in the first section 10 of the flow channel 9, which is formed normal to the suction plane E. The axis of rotation 5a of the axial impeller 5 is arranged normal to the suction plane E and parallel to the flow center axis 9a of the flow channel 9 in the first section 10. The axis of rotation 5a is arranged in the plane of symmetry a of the housing 2.

At the end of the second section 12 of the flow channel 9, which is arranged normal 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 area of the channel outlet opening 13. The flow center axis 9a of the flow channel 9 is arranged perpendicular to the suction plane E in the first section 10, which has the channel inlet opening 11, and parallel to the suction plane E in the second section 12, which has the channel outlet opening 13.

The channel outlet opening 13 is arranged against the direction of movement P, i.e. on the rear side R of the underwater cleaner 1.

The reference sign δ indicates a reference plane which is tangent to the lower channel wall 17 of the second section 12 in the area of the inner bend area 15.

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.

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 cannot tip over on the surface to be cleaned.

The underwater cleaner 1 has an essentially rectangular cross-section in the second section 12—in particular in the area of the channel outlet opening 13—with a height H measured normal to the suction plane E and a width B measured parallel to the suction plane ε (FIG. 4). The height H is at most 25%, for example at most 22%, of the width b. This enables a low design of the underwater cleaner 1.

A second distance b between the reference plane δ and the channel inlet opening 11 of the flow channel 9, as shown in FIG. 1, is at most 50% of the impeller radius r. This means that the first section 10 of the flow channel 9 can be kept particularly short, which enables 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, which prevents sucked-in particles from being thrown back in the direction of the suction plane E.

Due to the extremely short first section 10, the axial impeller 5 is also arranged in the area 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 blades 18 of the axial impeller 5. The 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 is approximately 10%±2% of the impeller radius r. In this way, the centrifugal effect of the axial impeller 5 can be utilized and stray dirt particles that are not entrained by the main flow can be thrown into the second section 12 of the flow channel 9 at the impeller outlet. This improves the cleaning effect.

In the outer bend 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 k₁ that 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 k₁ is at most 25%, for example at most 20%, of the impeller radius r. This prevents dirt particles from being thrown back again and thus increases the cleaning effect of the underwater cleaner 1.

The flow channel 9 has an at least partially cylindrical or slightly conical suction jacket 19 upstream of the axial impeller 5. The suction jacket 19 extends from the suction nozzle 6 via the channel inlet opening 11.

The suction nozzle 6 with the suction orifice 8 is arranged upstream of the channel inlet opening 11. The suction nozzle 6 has a layout that deviates from a circular basic shape 20 with a second radius of curvature k₂ and is essentially symmetrical in relation to the plane of symmetry a 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 either side of the central area 21. Wing areas 22 are understood here to be more or less pronounced bulges in relation to the circular basic shape 20 of the central area 21, which is indicated by dashed lines in FIG. 2. The central area 21 forms an essentially cylindrical bulge of 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 E. The lateral wing areas 22 are arranged outside the parallel projection of the channel inlet opening 11 onto the suction plane E.

The shape of the suction mouth 8 can also be described as triangular or roof-shaped—in each case with rounded corners.

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. The largest depth extension T measured in the area of the central area 21 is at least 50%, for example at least 55% of the largest width extension W.

The central area 21 is designed with the second radius of curvature k₂ 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 k₃, which is smaller than the second radius of curvature k₂ of the central area 21. The third radius of curvature k₃ is at most ½, in particular at most ⅓, for example at most ¼ of the second radius of curvature k₂.

Between the two lateral wing areas 22, the suction mouth 8 has a fourth radius of curvature k₄ on the front side F, which is at least twice, for example at least three times as large as the second radius of curvature k₂.

Between the central area 21 and each lateral wing area 22, the suction mouth 8 has a convex section 23. The convex section 23 forms a fifth radius of curvature k₅, which corresponds, for example, to the second radius of curvature k₂±20%.

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. An underwater cleaner, in particular for a swimming pool, comprising: a housing, in which a pump, in particular a battery-operated pump, with an electric motor and an axial impeller rotatable about an axis of rotation is arranged, having a suction nozzle formed by the housing with a suction mouth defining a suction plane and a flow channel which is arranged in the housing, accommodates the axial impeller and 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 center axis of the flow channel is arranged perpendicular 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, wherein the reference plane intersects the axial impeller in at least one region of the impeller blades and at least one impeller blade projects beyond the reference plane by a defined projection.

2. The underwater cleaner according to claim 1, wherein the first distance is at most 80 of the impeller radius.

3. The underwater cleaner according to claim 1, wherein a second distance (b) between the reference plane (δ) and the channel inlet opening of the flow channel is at most 50%, preferably at most 40%, particularly preferably at most 37%, of the impeller radius (r).

4. The underwater cleaner according to claim 1, wherein the axial impeller is arranged in the region of the channel inlet opening of the flow channel.

5. The underwater cleaner according to claim 1, wherein the axial impeller is arranged in the region of the reference plane (δ).

6. The underwater cleaner according to claim 1, wherein the projection is about 10%±2% of the impeller radius.

7. The underwater cleaner according to claim 1, wherein the flow channel has, in the transition between the first section and the second section, an outer bend area with a first radius of curvature (k1) which is smaller than the impeller radius (r), preferably smaller than half the impeller radius (r).

8. The underwater cleaner according to claim 7, wherein the first radius of curvature is at most 25 of the impeller radius.

9. The underwater cleaner according to claim 1, wherein the underwater cleaner in the second section has a 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 at most 25%.

10. The underwater cleaner according to claim 1, wherein the suction nozzle has a layout deviating from a circular basic shape with a single-symmetrical suction mouth.

11. The underwater cleaner according to claim 10, wherein the suction mouth is two-winged, wherein a lateral wing area is arranged on either side of a central area.

12. The underwater cleaner according to claim 11, wherein 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, wherein the largest depth extension measured in the central area is at least 50% of the largest width extension (W).

13. The underwater cleaner according to claim 11, wherein the central area comprises a second radius of curvature which is larger than the impeller radius.

14. The underwater cleaner according to claim 11, wherein the lateral wing areas each have a third radius of curvature which is smaller than the second radius of curvature of the central area, 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).

15. The underwater cleaner according to claim 11, wherein a fourth radius of curvature is formed between the two wing areas, which is at least twice as large as the second radius of curvature.

16. The underwater cleaner according to claim 11, wherein between the central area and each wing area, the suction mouth has a convex section, wherein the convex section forms a fifth radius of curvature, which corresponds to the second radius of curvature±20%.