IMPELLER PUMP

Description

Technical area

[0001] The present invention relates to an impeller pump with improved geometry of the inlet and outlet openings. Technical background

[0002] Impeller pumps use an impeller with a plurality of elastic impeller blades (also called impeller vanes) that rotates in a pump housing. The diameter of the impeller, i.e. the length of the impeller blades, is selected so that the free end of the impeller blades rests against the inner wall of the pump housing whatever the impeller's position. Between the drain opening and the inlet opening of the pump housing, the distance of the inner wall from the impeller's axis of rotation decreases. As a result, the impeller blades are bent (more strongly) when moving from the drain opening to the inlet opening than when moving from the inlet opening to the drain opening. As a result, the volume pumped from the drain opening to the inlet opening during one rotation of the impeller is smaller than the volume pumped from the inlet opening to the drain opening during one rotation of the impeller.This results in the medium to be pumped being conveyed from the inlet opening to the outlet opening.

[0003] Impeller pumps are particularly suitable for pumping liquids containing suspended solids and fibers, such as food waste. Another advantage of impeller pumps is that they are self-priming due to the sealing of the impeller blades against the pump housing.

[0004] Because the impeller blades are tightly pressed against the inner wall of the pump housing to ensure this seal, they are subject to wear. This wear is exacerbated by the fact that, as the impeller blades sweep over the inlet or outlet openings, they are pressed into these openings, particularly against their edges, both by their elasticity and by centrifugal forces.

[0005] Previously known techniques included equipping the inlet or outlet opening with a grid or "comb" to reduce this load on the impeller blades. However, with fluids containing suspended matter, especially fibrous components, this would result in the contaminants becoming trapped on the grid bars, reducing the pump's flow rate. Furthermore, hygiene concerns arise if the contaminants remain in the pump housing for an extended period.

[0006] Furthermore, EP 2 646 691 B1 discloses an impeller pump in which the inlet or outlet is elliptical. While this can reduce the depth of indentation of the impeller blades, due to the elliptical shape of the inlet or outlet, only a portion of the impeller blades come into contact with the edge of the ellipse, causing the impeller blades to wear more severely and thus unevenly there, which can lead to leaks.

[0007] DE 830 161 C shows a rotary lobe pump and relates in particular to a self-priming pump with a number of pump units located within a housing.

[0008] DE 10 2010 062298 A1 shows an impeller pump with a housing having an inlet and an outlet and with an impeller wheel with a plurality of elastic impeller blades.

[0009] DE 11 91 231 B shows a rotating positive displacement pump with a blade wheel having flexible, elastic blades projecting substantially radially from a hub, which rotates in a cylindrical pump chamber.

[0010] DE 82 23 151 U1 shows a liquid pump with a pump chamber contained in a pump housing, into which an inlet and an outlet opening for the liquid open and in which an impeller with flexible individual blades is rotatably arranged.

[0011] GB 1 059 902 A shows a flexible rotary vane pump which has an eccentrically mounted rotor with a metal core.

[0012] US 945 953 A shows a pump whose impellers are provided with curved outer surfaces. Description of the invention

[0013] Based on the known prior art, it is an object of the present invention to design an impeller pump in such a way that the above-mentioned disadvantages of the prior art are eliminated.

[0014] This object is achieved by an impeller pump according to independent claim 1. Preferred embodiments are specified in the subclaims, the figures and the description.

[0015] Accordingly, an impeller pump is proposed with a housing having an inlet and an outlet, and with an impeller wheel accommodated in the interior of the housing with a plurality of elastic impeller vanes. According to the invention, the cross-section of the inlet and / or the outlet has the shape of a polygon on the side facing the interior of the housing.

[0016] The inlet and the outlet have an inner inlet opening and an inner outlet opening, respectively, at which they each merge into the interior of the housing, in which the impeller wheel with the plurality of elastic impeller blades (for example made of rubber) is located.

[0017] The term "Cross-section" "Inlet" or "outlet" is to be understood here as being viewed from the inside of the housing along an axis defined by the inlet or outlet. This means, for example, that an inlet formed by a pipe with a circular cross-section has a circular cross-section, even if the actual shape of the inlet opening in the housing is no longer circular when unrolled onto a plane of the pump housing.

[0018] Since the inlet and outlet are openings, the polygon is usually a closed polygon.

[0019] Because the cross-section of the inlet and / or outlet is polygonal on the side facing the inside of the housing, when an impeller blade moves over the inlet or outlet, the impeller blade wipes evenly over the edges of the inlet or outlet. In other words, the contact point between the impeller blade and the respective edge of the inlet or outlet shifts essentially evenly, resulting in more even wear of the impeller blades, thus extending the service life of the individual impeller blades and thus extending the service life of the impeller wheel.

[0020] The polygon may preferably have a number of 3 to 17 vertices.

[0021] The shape of the cross-section of the inlet and outlet can be the same or different.

[0022] In a further preferred embodiment, the polygon has a longitudinal extension and a transverse extension, wherein the ratio of the length of the transverse extension to the length of the longitudinal extension is less than or equal to 1:2, preferably approximately 1:3 or approximately 1:4. As a result, for the same inlet or outlet cross-sectional area, the width of the inlet or outlet opening is correspondingly smaller, so that only a correspondingly narrower portion of the impeller blades does not come into contact with the housing wall during movement over the inlet or outlet opening. This correspondingly reduces the load on the impeller blades due to deformation when they are moved over the inlet or outlet opening.

[0023] Under "Longitudinal extension" This refers to the maximum length of the cross-section and its orientation. "Transverse extension"describes a maximum width of the cross-section that is oriented differently from the orientation of the longitudinal extent.

[0024] Preferably, the shape of the inlet or outlet is designed such that the longitudinal extent and the transverse extent are substantially perpendicular to each other.

[0025] In order to achieve uniform wear of the impeller blades when moving the impeller blades over the inlet or outlet opening and to achieve uniform flow conditions in the areas between the impeller blades as well as in the inlet and / or outlet, the polygon is designed symmetrically with respect to the longitudinal extent and / or symmetrically with respect to the transverse extent in a further preferred embodiment.

[0026] In a further preferred embodiment, the ratio of the length of the transverse extent of the polygon to the width of the impeller blades is less than 1:1, preferably less than or equal to 1:2, more preferably approximately 1:3 or approximately 1:4. This ensures that a sufficiently large portion of the impeller blades is always in contact with the housing wall when passing over the inlet or outlet opening. This firstly limits the deformation of the impeller blade due to immersion in the inlet or outlet opening. Secondly, a good seal is always ensured between the housing wall and the slightly deformed impeller blade. The polygon is preferably aligned such that the longitudinal extent extends along the direction of movement of the impeller blades.

[0027] In a particularly preferred embodiment, the polygon has at least one rounded corner, with all corners of the polygon preferably being rounded. This results in more uniform flow conditions during the pumping process.

[0028] In a further embodiment, the cross-section of the inlet and / or outlet on the side facing away from the housing interior has the shape of a circle or a polygon, preferably a rectangle, particularly preferably a square. This allows the impeller pump described here to be connected to conventional pipelines or in special arrangements.

[0029] Preferably, the area of ​​the corresponding cross-section on the side facing the housing interior and the area of ​​the corresponding cross-section on the side facing away from the housing interior differ by less than 10%; preferably, they are essentially the same. This enables a uniform inflow into the pump and outflow from the pump, since the medium to be pumped cannot accumulate at a constriction or develop turbulence due to a large cross-sectional increase.

[0030] Alternatively, the area of ​​the corresponding cross-section on the side facing the housing interior and the area of ​​the corresponding cross-section on the side facing away from the housing interior can differ, preferably by 15% - 75%, particularly preferably by 30% - 60%, and most preferably by approximately 50%. This allows a cross-section with a particularly small or short transverse extension to be implemented, so that the impeller blades are correspondingly only slightly deformed and worn.

[0031] The above-mentioned object is further achieved by an impeller pump according to the independent claim 6. Preferred embodiments are specified in the subclaims, the description and the figures.

[0032] Accordingly, an impeller pump is proposed with a housing having an inlet and an outlet, and with an impeller wheel accommodated in the housing interior and rotatable about a rotational axis, having a plurality of elastic impeller blades. The cross-section of the inlet and / or the outlet on the side facing the housing interior has a longitudinal extension and a transverse extension, wherein the length of the longitudinal extension is greater than the length of the transverse extension. According to the invention, the longitudinal extension forms an angle with the rotational axis that is greater than 0° and less than 90°.

[0033] Because the longitudinal extension forms an angle with the rotational axis, more even wear of the individual impeller blades is achieved. Unlike conventional impeller pumps, the impeller blade does not come into symmetrical contact with the edge of the inlet or outlet opening at the same points on the impeller blades before and after passing over the center of the inlet or outlet opening. Instead, the blade passes over the inlet or outlet opening in a substantially uniform pattern from one side of the impeller blade to the other.

[0034] In other words, the contact point of the impeller blade shifts transversely to the direction of movement of the impeller blades as it moves past the inlet or outlet opening. At the same time, the maximum width over which the individual impeller blades do not come into contact with the housing wall remains relatively small due to the larger longitudinal extension compared to the transverse extension, resulting in only slight deformation of the impeller blades and reduced immersion of the impeller blade into the inlet or outlet opening.

[0035] The term "Angle"This refers to the angle that forms between the longitudinal extension—or its extension, if applicable—and the rotational axis when viewed from above. In other words, to determine the angle, the impeller's rotational axis must be projected onto a plane defined by the cross-section. The angle then corresponds to the angular dimension between the longitudinal extension and the projection of the rotational axis.

[0036] The orientation of the longitudinal extension can be different for the inlet and the outlet, but can also have the same orientation.

[0037] The angle is preferably greater than or equal to 15° and less than or equal to 75°, particularly preferably greater than or equal to 30° and less than or equal to 60°, and very particularly preferably approximately 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40° or 45°.

[0038] In a further embodiment, the cross-section has the shape of an ellipse or a polygon.

[0039] To further adapt the flow conditions during pumping, in a preferred embodiment, the polygon has at least one rounded corner, with all corners preferably being rounded. If the polygon is designed as an elongated rectangle, the radii of the curves preferably correspond to half the width of the rectangle; they are thus selected to form an elongated hole.

[0040] In a particularly advantageous preferred embodiment, the ratio of the length of the transverse extension to the width of the impeller blades is less than 1:1, preferably less than or equal to 1:2, more preferably about 1:3 or about 1:4.

[0041] In order to minimize the deformation of the impeller lamellae when moving the impeller lamellae over the inlet or outlet opening, the ratio of the length of the transverse extension to the length of the longitudinal extension is, according to a preferred embodiment, less than or equal to 1:2, preferably less than or equal to 1:3 or approximately 1:4.

[0042] In a further preferred embodiment, the ratio of the width of the impeller blades to a cross-sectional width parallel to the width of the impeller blades is greater than or equal to 3:2, preferably greater than or equal to 2:1. This allows the deformation of the impeller blades to be further minimized when moving over the inlet or outlet opening.

[0043] In a further preferred embodiment, the cross-section of the inlet and / or the outlet on the side facing away from the housing interior has the shape of a circle or the shape of a polygon, preferably a rectangle, particularly preferably a square, wherein the area of ​​the cross-section on the side facing the housing interior and the area of ​​the associated cross-section on the side facing away from the housing interior preferably differ by less than 10%, preferably being substantially the same. Alternatively, the area of ​​the associated cross-section on the side facing the housing interior and the area of ​​the associated cross-section on the side facing away from the housing interior can differ, preferably by 15% - 75%, particularly preferably by 30% - 60% and most preferably by approximately 50%. The above-mentioned advantages are thereby achieved.

[0044] In a further preferred embodiment of the aforementioned impeller pumps, at least one edge of the inlet and / or outlet at the transition to the housing interior has a chamfer or is rounded, wherein preferably all edges of the inlet and / or outlet at the transition to the housing interior have a chamfer or are rounded. This reduces the pressure exerted on the impeller blade by the edge due to the deformation and contact force of the impeller blade. Furthermore, a soft pressure point profile is obtained on the impeller blade. It is also possible for at least one edge to be rounded and at least one other edge to have a chamfer.

[0045] In a further embodiment of the aforementioned impeller pumps, the transition of the inner wall of the housing from a region of maximum diameter to a region of reduced diameter essentially coincides with the transverse extent of the cross-section of the inlet or outlet opening. This transition does not occur abruptly, but rather the distance of the inner wall of the housing from the rotational axis of the impeller wheel decreases continuously from the maximum distance at which the impeller blades are not bent or are bent to the minimum distance at which the impeller blades are bent to the greatest extent. Short description of the characters

[0046] Preferred further embodiments are explained in more detail in the following description of the figures. They show: Figure 1 schematically shows a sectional view of an impeller pump; Figure 2 schematically shows an impeller wheel; Figure 3 schematically shows a perspective side view of a housing of an impeller pump; Figure 4 schematically shows a further embodiment of an impeller pump; Figure 5 schematically shows a further embodiment of an impeller pump with a cross-section in the form of a polygon with six corners; Figure 6 schematically shows a further embodiment of an impeller pump, the longitudinal extension of the inlet opening cross-section of which forms an angle with the axis of rotation of the impeller wheel on a plane defined by the cross-section; Figure 7 the impeller pump from Figure 6in a schematic perspective side view; Figure 8 shows a schematic sectional view of an impeller pump in a further embodiment; Figures 9-14 schematically show various polygonal embodiments of cross sections of the inlet and outlet, respectively; Figure 15 schematically shows a cross section which has the shape of an ellipse; Figures 16 to 21 schematically show various polygonal embodiments of cross sections of the inlet and outlet, respectively; and Figures 22-24 schematically show various embodiments of cross sections whose longitudinal extent forms an angle with the axis of rotation of the impeller wheel. Detailed description of preferred embodiments

[0047] Preferred embodiments are described below with reference to the figures. Identical, similar, or equivalent elements in the different figures are provided with identical reference numerals, and a repeated description of these elements is partially omitted to avoid redundancies.

[0048] From the representation according to Figure 1the operating principle of an impeller pump is clearly visible. The housing 1 of the impeller pump has an inlet 2 and an outlet 3. Inside the housing 1, an impeller wheel 4 is mounted so as to rotate in the direction of the arrow about a rotation axis D. The impeller wheel 4 has a plurality of impeller blades 5, the blade ends 6 of which rest against the inner wall 7 of the housing 1. The interior of the housing 1 is not rotationally symmetrical about the rotation axis D, but is shaped such that the impeller blades 5 are not deformed or are only slightly deformed when moving from the inlet opening 8 to the outlet opening 9, while they are bent against the direction of rotation of the impeller wheel 4 when moving from the outlet opening 9 to the inlet opening 8.As a result, the volume between two impeller blades 5 during the movement from the inlet opening 8 to the outlet opening 9 is greater than the volume during the movement from the outlet opening 9 to the inlet opening 8, whereby the medium to be pumped is conveyed from the inlet opening 8 to the outlet opening.

[0049] In Figure 2 an impeller wheel 4 is shown, the impeller blades 5 of which are reinforced at their end 6 with a wire 10 in order to minimize the deformation of the blade end 6 when passing over the inlet opening 8 and the outlet opening 9.

[0050] Figure 3shows a perspective side view of the housing of an impeller pump. The housing 1 of the impeller pump is composed of two parts 1a, 1b that are axially symmetrical with respect to the axis R along a parting plane 11. Projections 12 on one housing part 1b, which engage in corresponding recesses 13 on the other housing part 1a and thereby facilitate the assembly of the two housing parts 1a, 1b, ensure a slight deviation of the contact surfaces between the two parts 1a, 1b from the parting plane. The two housing parts 1a, 1b are held together by several screw connections 14.

[0051] Sealing elements can be provided between the two housing parts 1a, 1b, which can also take over the function of the projections 12 and recesses 13, for example if a sealing element engages in a groove formed in both housing parts.

[0052] In this embodiment, the inlet opening 8 and the outlet opening (not shown) each have a cross-section in the form of a diamond-shaped polygon. As also Figure 3 As can be seen, the interior of the housing 1 of the impeller pump consists of an area in which the distance between the inner wall 7 and the axis of rotation D of the impeller wheel 4 is maximum, namely when the impeller blades 5 move from the inlet opening 8 to the outlet opening 9. Furthermore, there is an area in which this distance is reduced, when the impeller blades 5 move from the outlet opening 9 to the inlet opening 8, in order to achieve a deformation of the impeller blades 5.

[0053] The continuous transition from the area with maximum distance to the area with minimum distance begins at the level of the maximum transverse extension of the rhombus of the inlet opening 8 or the outlet opening 9, i.e. approximately in the middle of the inlet opening 8 or the outlet opening 9. Figure 3 The housing 1 shown is shown without a side panel. This can be manufactured separately from the two housing parts 1a, 1b and connected to the corresponding housing part 1a, for example, by screwing or gluing. However, the housing part can also be manufactured with a side panel.

[0054] Clamping screws 15 on the inlet 2 and the outlet 3 can be used to connect connecting pipes to the inlet 2 or outlet 3 of the housing 1.

[0055] In Figure 3 The elongated and narrow shape of the inlet opening 8 can also be seen, which leads to the impeller blades 5 of the Figure 3 not shown impeller wheel 4 are not pushed outwards and deformed as strongly by the centrifugal forces arising from the rotation of the impeller wheel 4 and the elastic restoring forces due to the deformation of the impeller blades 5 as in impeller pumps in which the inlet opening extends over the entire width - or almost the entire width - of the impeller blades and thus also the interior of the housing. Figure 3 The drain opening 9, which cannot be seen, is preferably designed identically to the inlet opening 8.

[0056] Although the shape of the inlet opening 8 in Figure 3 appears irregular due to the irregular curvature of the inner wall 7, the cross section of the inlet opening 8, i.e. the view of the inlet opening 8 from the inside of the housing along the axis Z defined by the inlet, has the shape of a regular rhombus. This is well Figure 4which shows a section through an impeller pump along a plane E perpendicular to the axis Z defined by the inlet.

[0057] Figure 4 shows an embodiment of the impeller pump in which the housing 1 is connected to a drive unit 16 that drives the impeller wheel 4 (not shown). In this illustration, the diamond shape of the cross section of the inlet opening 8 is clearly visible. The longitudinal extension L of the polygon, which runs in the dividing plane 11 between the two housing parts 1a, 1b, has, in this embodiment, approximately three times the length of the transverse extension Q. The length of the transverse extension Q is approximately one-third of the width of the inner wall 7 of the housing, i.e., approximately one-third of the width of the impeller blades 5.

[0058] The Figure 5 The design of the impeller pump shown essentially corresponds to that of Figure 4, wherein the shape of the cross section has a polygon with six corners. The longitudinal extension L of the polygon, which runs in the parting plane 11 between the two housing parts 1a, 1b, has in this embodiment approximately three times the length of the transverse extension Q. Compared to the cross section of Figure 4 the cross-section shows Figure 5 a larger cross-sectional area, so that a larger volume flow can be pumped at the same pressure conditions during pumping operation.

[0059] Figure 6 shows a further embodiment of an impeller pump, which in its construction is essentially the same as that shown in Figures 3 to 5 impeller pumps shown. The impeller pumps shown in Figure 6The impeller pump shown further comprises an inlet which, on the side facing the housing interior, has a cross-section with a longitudinal extension L and a transverse extension Q, wherein the longitudinal extension L forms an angle a with the rotational axis D of the impeller wheel (not shown). In the present case, the angle a is 60°.

[0060] The cross section of the inlet opening 8 from Figure 6 has the shape of an ellipse.

[0061] However, the angle a can also have other values, for example 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, or 85°, and can be arranged in a positive or negative direction of rotation.

[0062] Preferably, the longitudinal extension L of the inlet opening 8 and the longitudinal extension of the outlet opening 9 are arranged parallel. Alternatively, the two longitudinal extensions can also be oriented differently.

[0063] In Figure 7the impeller pump is off Figure 6 shown in a schematic perspective side view. It can be clearly seen here that an impeller blade, when moving along the inlet opening 8, first comes into contact with the edges of the inlet opening 8 in the area of ​​its one end. As the impeller blades move further, the contact points between the impeller blade and the edges of the inlet opening 8 move along the impeller blade into the area of ​​the other end of the impeller blade. Thus, after moving across the inlet opening 8, the impeller blade essentially came into contact with the edges of the inlet opening 8 across its entire width, with the contact points continuously shifting. Since, as shown in the detail of the Figure 23As can be seen, the cross-sectional width b of the cross section parallel to the width of the impeller blade is only slightly wider than the transverse extension Q due to the slender, elongated shape of the cross section. This minimizes deformation of the impeller blade when moving over the inlet opening. The impeller blade thus experiences uniform and minimal wear across its entire width, enabling a long service life for the impeller wheel used.

[0064] Figure 8 shows a schematic sectional view of an impeller pump in another embodiment. The longitudinal extension L forms an angle a of 45° with the rotational axis D in this case.

[0065] In the embodiments of the impeller pump shown in the figures, the inlet 2 and the outlet 3 have the shape of a circle at their outer ends facing away from the interior of the housing in order to be able to easily connect normal, round connecting pipes to the inlet 2 and the outlet 3.

[0066] In Figure 8 In this regard, it is clearly visible that the area of ​​the circle of the outer inlet opening 17 and the cross section of the inner inlet opening 8 are approximately the same size in order to enable uniform transport of the medium to be pumped.

[0067] In the Figure 8 In the embodiment shown, the circular cross-section at the outer end facing away from the interior of the housing gradually transitions to the elliptical cross-section of the inlet opening 8, thus without abrupt jumps in the cross-sectional profile along the Z axis.

[0068] Figures 9 to 25 schematically show various designs of the cross section for the inlet and / or the outlet with their respective longitudinal extent L and their respective transverse extent Q.

[0069] The Figure 9 The schematically shown cross-section has a polygon in the shape of an elongated rectangle, so that an inlet with a rectangular elongated hole shape is formed.

[0070] The Figure 10 The schematically illustrated cross-section has a polygon in the shape of a regular rhombus. The transverse extension Q and the longitudinal extension L thus intersect at their respective centers.

[0071] The Figure 11 The schematically illustrated cross-section has a polygon in the shape of a rhombus, in which the transverse extension Q divides the longitudinal extension L in a ratio of 2:1.

[0072] The Figure 12 The schematically shown cross-section has a polygon in the shape of a hexagon.

[0073] The Figure 13 The schematically shown cross-section has a polygon in the shape of another hexagon.

[0074] The Figure 14 The schematically shown cross section corresponds to that of Figure 9 , with the corners of the cross-section rounded to create a rounded slot. The radii of the curves are chosen to form semicircular ends.

[0075] The Figure 15 The schematically shown cross-section has the shape of an ellipse.

[0076] The Figure 16 The schematically shown cross-section corresponds to that of the Figure 12 , whereby the corners located at both ends, viewed in the longitudinal extension L, are rounded.

[0077] The Figure 17 The schematically shown cross-section corresponds to that of the Figure 13, wherein the corners located at both ends, as seen in the longitudinal extension L, are rounded in such a way that a single rounding is created at each corner.

[0078] The Figure 18 The schematically shown cross-section has a quadrangular polygon in which the longitudinal extension L coincides with the longest edge of the polygon.

[0079] The Figure 19 The schematically shown cross-section has an octagonal polygon whose transverse extension Q is constant over the longitudinal extension L.

[0080] The Figure 20 The schematically shown cross-section corresponds to that of the Figure 20 , where the edges which have a component in the longitudinal extension L have different curvatures, such that a polygon with four corners is created, where three edges of the cross section each consist of Figure 20 an S-shaped curved edge is formed.

[0081] In the Figures 9 to 20 In the cross-sections shown, the longitudinal extent L and the transverse extent Q are oriented perpendicular to each other.

[0082] As a rule, the longitudinal extension in these embodiments is arranged perpendicular to the axis of rotation D. In the Figures 9 to 20 In the cross-sections shown, the transverse extension Q extends parallel to the impeller's axis of rotation D. Alternatively, the longitudinal extension L and the axis of rotation D can also form an angle.

[0083] The Figure 21 The schematically illustrated cross-section shows a quadrangular polygon in which the longitudinal extent L and the transverse extent Q are oriented at an angle other than 90°.

[0084] The Figures 22 to 24 schematically illustrated cross sections of the inlet opening and the outlet opening can be seen, in which the longitudinal extension L forms an angle a with the axis of rotation D.

[0085] The Figure 22 The cross-section shown schematically has the shape of an ellipse. Thus, the longitudinal extent L coincides with the major axis of the ellipse and the transverse extent Q coincides with the minor axis of the ellipse. The angle α in this case is approximately 60°. The reference symbol β indicates the cross-sectional width parallel to the width of the impeller blades, thus perpendicular to the axis of rotation D. This cross-sectional width β corresponds to the part of the impeller blade that does not come into contact with the housing wall during movement along the opening. Due to the elliptical shape of the cross-section, the cross-sectional width β varies depending on the position of the impeller blade at the opening defining the cross-section.

[0086] The Figure 23The schematically shown cross-section has the shape of a rhombus. The angle a in this case is approximately 45°. Due to the special design of the cross-section, the transverse extension Q and the maximum cross-sectional width b, which is also oriented at an angle of 45°, have approximately the same vector length.

[0087] The Figure 24 The schematically shown cross-section corresponds to that of the Figure 22 , where the angle a in this case is approximately 45°.

[0088] Where applicable, all individual features presented in the embodiments may be combined and / or exchanged without departing from the scope of the invention. List of reference symbols

[0089] 1 Housing 1a, 1b Housing parts 2 Inlet 3 Outlet 4 Impeller wheel 5 Impeller blade 6 Blade end 7 Inner wall 8 Inner inlet opening 9 Inner outlet opening 10 Wire reinforcement 11 Division plane 12 Projection 13 Recess 14 Screw connection 15 Clamping screw 16 Drive unit 17 Outer inlet opening 18 Outer outlet opening LLongitudinal extent QTransverse extent bCross-sectional width DRotation axis RAxis Zaxis aAngle

Claims

1. Impeller pump with a housing (1) having an inlet (2) and an outlet (3) and with an impeller wheel (4), accommodated in the housing interior, with a plurality of elastic impeller blades (5), wherein the inlet (2) has exactly one inlet opening (8) with which it merges into the housing interior and wherein the outlet (3) has exactly one outlet opening (9) with which it merges into the housing interior, characterized in that a cross-section of the inlet opening (8) of the inlet (2), representing a view of the inlet opening (8) as viewed from the interior of the housing (1) along an axis (Z) defined by the inlet (2), and / or a cross-section of the outlet opening (9) of the outlet (3) representing a view of the outlet opening (9) as viewed from the interior of the housing (1) along an axis defined by the outlet (3) has the shape of a polygon.

2. The impeller pump according to claim 1, wherein the polygon has a longitudinal extension (L) corresponding to a maximum length of the cross section and a transverse extension (Q) oriented differently from an orientation of the longitudinal extension (L) and corresponding to a maximum width of the cross section, wherein the ratio of the length of the transverse extension (Q) to the length of the longitudinal extension (L) is less than or equal to 1:2, preferably about 1:3 or about 1:4.

3. The impeller pump according to claim 1 or 2, wherein the polygon is symmetrical with respect to the longitudinal extension (L) and / or symmetrical with respect to the transverse extension (Q).

4. The impeller pump according to any one of the preceding claims, wherein the ratio of the length of the transverse extension (Q) of the polygon to the width of the impeller blades (5) is less than 1:1, preferably less than or equal to 1:2, more preferably about 1:3 or about 1:4.

5. The impeller pump according to any one of the preceding claims, wherein the polygon has at least one rounded corner, wherein preferably all corners of the polygon are rounded.

6. The impeller pump with a housing (1) having an inlet (2) and an outlet (3), and with an impeller wheel (4), accommodated in the housing interior and rotatable about a rotational axis (D), with a plurality of elastic impeller blades (5), wherein the inlet (2) has exactly one inlet opening (8) with which it merges into the housing interior, and wherein the outlet (3) has exactly one outlet opening (9) with which it merges into the housing interior, wherein a cross-section of the inlet opening (8) of the inlet (2), representing a view of the inlet opening (8) as viewed from the interior of the housing (1) along an axis (Z) defined by the inlet (2), and / or a cross-section of the outlet opening (9) of the outlet (3) representing a view of the outlet opening (9) as viewed from the interior of the housing (1) along an axis defined by the outlet (3) has a longitudinal extension (L) corresponding to a maximum length of the cross-section, and a transverse extension (Q), oriented differently from an orientation of the longitudinal extension (L), and corresponding to a maximum width of the cross-section, wherein the length of the longitudinal extension (L) is greater than the length of the transverse extension (Q), characterized in that the longitudinal extension (L) of the cross-section includes an angle (α) greater than 0° and less than 90° with a projection of the rotational axis (D) onto a plane defined by the cross-section.

7. The impeller pump according to claim 6, wherein the angle (α) is approximately 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40° or 45°, wherein the angle (α) is preferably greater than or equal to 15° and less than or equal to 75°, preferably approximately 15°, 20°, 25°, 30°, 35°, 40° or 45°, most preferably greater than or equal to 30° and less than or equal to 60°, preferably approximately 30°, 35°, 40° or 45°.

8. The impeller pump according to claim 6 or 7, wherein the cross section has the shape of an ellipse or a polygon.

9. The impeller pump according to any one of claims 6 to 8, wherein the ratio of the length of the transverse extension (Q) to the width of the impeller blades (5) is less than 1:1, preferably less than or equal to 1:2, more preferably about 1:3 or about 1:4.

10. The impeller pump according to one of claims 6 to 9, wherein the ratio of the length of the transverse extension (Q) to the length of the longitudinal extension (L) is less than or equal to 1:2, preferably less than or equal to 1:3 or about 1:4.

11. The impeller pump according to any one of claims 6 to 10, wherein the ratio of the width of the impeller blades to a cross-sectional width (b) parallel to the width of the impeller blades (5) is greater than or equal to 3:2, preferably greater than or equal to 2:1.

12. The impeller pump according to any one of the preceding claims, wherein at least one edge of the inlet (2) and / or the outlet (3) has a chamfer or is rounded at the transition to the housing interior, wherein preferably all edges of the inlet (2) and / or the outlet (3) have a chamfer or are rounded at the transition to the housing interior.