LU102816B1 - double pump unit - Google Patents

Abstract

The invention relates to a double pump unit (1) comprising a first and a second centrifugal pump with a common pump housing (2), in which a pump chamber (3, 4) of the first and second centrifugal pump is formed, of which a pressure channel (5, 6th ) opens into a common flap space (7), which merges into an outlet channel (8) and in which a flap (9) is arranged, which is held pivotably with a holding section (10) in a receiving space (11) of the pump housing (2). and selectively closes one or the other pressure channel (5, 6). According to the invention, the flap (9) is held floating in the receiving space (11) without a shaft.

Description

WI 810032 B

1.6.2021

WILO SE Wilopark 1 44263 Dortmund Double pump unit The invention relates to a double pump unit comprising a first and a second centrifugal pump with a common pump housing, in which a pump chamber of the first and second centrifugal pump is formed, of which a pressure channel opens into a common flap chamber, which in merges into a common outlet channel and in which a flap is arranged, which is pivotally held with a holding section in a receiving space of the pump housing and optionally closes one or the other pressure channel. Double pump units of this type are generally known, for example from German patent applications DE19511170 A1 or DE 102014006258 A1. The flap, also called double pump flap in technical jargon, is pivotably mounted on a shaft in the form of a pin, which is mounted in the pump housing from the outside. Both the pin and the pump housing are specially machined for this. The pump housing has a special threaded hole that is open to the outside world and through which the pin is inserted into the pump housing. The pin in turn has an external thread at one axial end, with which it is screwed into the threaded hole in the pump housing. In order to achieve tightness, the thread is self-sealing and is also glued with an adhesive in the threaded hole. In addition, the threaded hole is sealed with a plug. It goes without saying that the production of this bearing for the double pump flap is technically complex. Furthermore, due to the threaded hole in the pump housing, there is always a certain, albeit minimal, risk of leakage with regard to the long service life of a double pump.

Finally, the assembly of the double pump flap in the pump housing is tedious and difficult, since it first has to be inserted through the narrow outlet channel into the flap chamber, then aligned with the hollow profile of its insertion end with the threaded hole and held in such a way that the pin has to be held in this position to be inserted into the hollow profile. The object of the present invention is to overcome the disadvantages mentioned and to provide a double pump unit with a pump housing in which the flap can be mounted easily and without additional components. This problem is solved by a double pump unit with the features of claim 1. Advantageous developments are specified in the dependent claims and are explained below.

According to the invention, it is provided that the flap with the holding section is held floating in the receiving space without a shaft. In other words, the holding section sits loosely in the receiving space. There is thus no shaft around which the flap can be pivoted. The geometric axis about which the flap can be pivoted is not stationary as in the prior art, but rather its position can be changed relative to the pump housing. The flap can therefore be pivoted about an axis that can change its position. In addition, there is play on all sides around the holding section, which allows the flap to move relative to the pump housing in all spatial directions. The floating mount already leads to a higher mobility of the flap due to the play. In addition, mobility is increased as a result of the missing shaft, because this always formed a frictional resistance when pivoting the flap.

A further advantage of the play around the holding section is that the inner wall of the receiving space does not have to be reworked. Rather, it can remain rough due to the manufacturing process. For example, the pump housing can be made of gray cast iron using a lost mold core made of sand to form the receiving space

Generally leads to very rough inner surfaces with bumps.

However, this is irrelevant for the floating mounting according to the invention.

The flap can thus still optionally close one or the other pressure channel without hindrance, but no additional components such as the separate shaft or the pin, an adhesive or a plug for closing the bore in the pump housing are required to hold it.

This same bore can also be dispensed with.

Manufacturing and processing steps, in particular on the pump housing, are thus omitted in the double pump unit according to the invention, which simplifies the manufacturing process.

At the same time, there is no longer any risk of leakage due to the lack of a hole.

In one embodiment variant, the receiving space can open towards the flap space via an opening that is narrower than the holding section.

In order to insert the flap into the receiving space, the holding section can be elastic in such a way that it can be compressed to a width that is less than or equal to the width of the opening.

In other words, when the flap is inserted into the receiving space, the holding section is compressed/squeezed in order to pass through the opening and, after overcoming the opening, returns to its natural shape without any force stress, so that it engages behind the opening.

In this way, a loose form fit is achieved.

This variant not only enables the flap to be fitted quickly and easily in the pump housing.

The flap is also held securely in the receiving space and can be easily removed again or the holding section can be pulled out of the receiving space again, since the form fit can be easily released again.

When it is pulled out, the holding section is compressed again, so that it can overcome the narrower opening again.

No special tools are required to insert the flap.

If necessary, simple needle-nose pliers can be used if your hand does not fit through the outlet opening of the outlet channel, i.e. does not fit through the pressure connection.

In order to further facilitate the insertion, the opening to the receiving space can be aligned with the exit opening of the exit channel.

In order to maintain the elasticity of the holding section, it can be provided in one embodiment variant that the holding section is made of an elastic material, in particular a material that is so soft that it can be damaged even if the holding section is solid, i.e. if the holding section is made of solid material , can be sufficiently compressed to overcome the opening to the receiving space.

The holding section is preferably formed by a hollow body, in particular a hollow profile.

This also causes the holding section to be elastic, since it can be deformed more easily, so that the material does not have to be as soft as in the case of a holding section made of solid material.

In one embodiment variant, the cross section of the holding section and of the receiving space can each be circular.

This circular shape has the advantage that even if solids are deposited in the receiving space over time, the flap with its holding section continues to slide well over these solid deposits at any pivoting angle.

Alternatively, the holding section can also be oval or in the form of a “0”.

Furthermore, it does not necessarily have to be closed.

For example, a C-shape, T-shape or V-shape are also possible, as long as the holding section reaches behind the opening to the receiving space.

It is advantageous if the holding section has at least a play of 1 mm on all sides.

In the case of a circular shape, the receiving space then has an inside diameter that is at least 2 mm larger than the outside diameter of the holding section.

Such a large clearance has the advantage that solid particles, which can accumulate over time at the bottom of the receiving space, do not impair the mobility of the flap.

According to one embodiment variant, the receiving space can be approximately symmetrical and have a first and second side wing, with the holding section being shaped in such a way that when one pressure channel is closed it rests at least predominantly in the second side wing and when the other pressure channel is closed it lies at least predominantly in the first side wing , and the one pressure channel and the second side wing on the one hand and the other pressure channel and the first side wing on the other hand are each located on opposite sides of an axis of symmetry of the receiving space.

With such an arrangement, a maximum of flexibility is created for the geometry of the pump housing.

For example, said receiving space with the side wings can be narrower in the direction of the flap space than in the direction of the side wings.

The floating mount according to the invention can also be used in pump housings in which the location of the pump chambers and/or their pressure channels and/or the required pivoting angle (position and opening angle) of the flap make it impossible for the receiving space and the holding section to have a circular cross section goes.

Viewed in cross section, the holding section can have a width that is greater than its height.

Such a flap can advantageously lie in a receiving space that is narrower in the direction of the flap space than in the direction of its side wings.

In order to completely rule out the risk of leakage, the wall of the receiving space can be free of passages, in particular bores, to the outside.

A particularly simple production of the flap is achieved when the holding section is in one piece with a flap body that closes one or the other pressure channel.

In particular, the holding section and the flap body can be made of the same material in one piece.

However, there is also the possibility of manufacturing the flap body separately and then joining it to the holding section, for example by means of a form fit and/or an adhesive bond.

This has the advantage that different materials can be used for the flap body and the holding section.

The form fit can be done, for example, in the manner of a dovetail.

Further features, properties, effects and advantages of the invention are explained in more detail below using exemplary embodiments and the attached figures.

The reference symbols contained in the figures retain their meaning from figure to figure.

In the figures, reference symbols always denote the same or equivalent components, areas, directional or locational information.

It should be pointed out that, in the context of the present description, the terms “have”, “comprise” or “contain” in no way exclude the presence of other features.

Furthermore, the use of the indefinite article with an object does not exclude its plural form.

1 shows a radial cross-section through a pump housing of a first double pump unit according to the invention. FIG. 2 shows a front view of the flap in the pump housing according to FIG. 1 of the flap in the pump housing according to Figure 1 Fig. 5: a radial cross section through a pump housing of a second double pump unit according to the invention Fig. 6: a front view of the flap in the pump housing according to Figure 5 Fig. 7: a side view of the flap in the pump housing according to Figure 5 Fig. 8 1 shows a section through a pump housing 2 of a double pump unit 1 according to a first embodiment along a radial plane perpendicular to the two pump axes.

The other components of the double pump unit 1 are not shown.

FIGS. 2 to 4 show a flap 9 used in the double pump unit 1 in different views.

The double pump unit 1 has two centrifugal pumps driven by an electric motor, the pump axes of which are parallel in this embodiment.

The centrifugal pumps can be designed as glandless pumps, so that the respective motor shaft forms the pump shaft at the same time.

The two pump shafts each carry an impeller at their respective ends, which is arranged in a pump chamber 3, 4 in each case.

The two pump chambers 3, 4 are shown in FIG

1 shown.

You are part of the pump housing 2, so that the pump housing 2 is a common component of both centrifugal pumps.

The pump housing 2 has an inlet opening 17 which leads into an inlet channel 16 which is radial to the pump axes and which is divided into two suction channels 13, 14, of which one suction channel 13, 14 leads in the axial direction into one of the two pump chambers 3, 4 flows.

One of the impellers is arranged in the respective mouth opening.

A pressure channel 5 , 6 in the pump housing 2 of each of the two pump chambers 3 , 4 opens into a common valve chamber 7 , which merges into an outlet channel 8 .

The outlet channel 8 has an outlet opening 13, which is located in the so-called pressure port.

Correspondingly, the inlet opening 17 is located in a so-called suction port.

The suction and pressure connections are aligned coaxially here, so that the double pump unit 1 forms a so-called inline pump, which is connected to a hydraulic pipe system with the suction and pressure connections.

In the flap space 7 a flap 9 is arranged, which is also referred to as a double pump flap.

It is held pivotably with a holding section in a receiving space 11 of the pump housing 2 and can thereby selectively close the first or second pressure channel 5, 6.

The flap 9 is held in the receiving space 11 in a floating manner.

In comparison to the prior art, the flap 9 is not mounted on a shaft that extends through the receiving space 11 .

Consequently, the flap 9 is held without waves, which means that the holding section 10 is not stationary relative to the pump housing 2 .

Thus, the position of the axis about which the flap 9 can be pivoted can be changed relative to the pump housing 2 .

There is also play on all sides around the holding section 10, which allows a relative movement of the flap 9 to the pump housing 2 in all spatial directions.

The play can be seen in FIG. 1, with the flap 9 being supported on the base of the receiving space 11 due to its own weight, however, in this illustration showing the double pump unit 1 in its non-operating state.

It should be emphasized that this contact between the holding portion 11 and the pump housing 2 due to the lack of fixation of the flap 9 in the

Pump housing 2 is still understood as a game, since the flap 7 in any case has the opportunity to float.

The all-round play is achieved in that the outer dimensions of the holding section 10 are smaller in every spatial direction than the inner dimensions of the receiving space 11. As can be seen in Figure 1, this embodiment variant has a holding section 10 with a circular cross section, with the receiving space 11 also in cross-section is circular.

Consequently, in order to achieve play on all sides, the outer diameter of the holding section 10 is smaller than the inner diameter of the receiving space 11, for example by 5 mm, so that there is a play of 2.5 mm.

This has the advantage that the inner surface of the receiving space, which is very rough due to the production of the pump housing from cast metal using a sand core, does not have to be machined.

At the same time, the respective sealing surface 25 of the pump housing 2 around the opening of the corresponding pressure channel 5, 6 in the flap chamber 7 is dimensioned laterally sufficiently large so that the flap 9 also completely closes the corresponding pressure channel 5, 6 through its contact with the sealing surface 25 when because of its mobility, it is sometimes positioned higher, sometimes further down, sometimes further to the right or sometimes further to the left.

The receiving space 11 opens towards the flap space 7 via an opening 12 through which the holding section 10 is inserted into the receiving space 10 .

The opening 12 is delimited laterally by a web 23, 24 each, so that the opening 12 lies between these two webs 23, 24.

A first of these webs 23 is formed between the first pressure channel 5 and the receiving space 11 , the second of these webs 24 is formed between the second pressure channel 6 and the receiving space 11 .

The end faces of these webs 23, 24 each form part of the sealing surface 25 which surrounds the orifice in the form of a ring.

The sealing surface 25 forms, so to speak, a stop for the flap 9. So that the flap 9 remains with its holding section 10 in the receiving space 11, the opening 12 is narrower than the holding section 10 or the holding section 10 is wider than the opening 12, so that it separates the two Webs 23, 24 engages behind.

In order to ensure its insertion through the opening 12, the holding section 11 is elastic in such a way that it can be compressed to a width which is less than or equal to the width of the opening 12.

In the embodiment variant according to FIG. 1, this is achieved in that the holding section 10 is made from an elastic material, for example from EPDM, preferably with a hardness of between 60 and 90 Shor.

In addition, the holding section 10 is designed as a hollow body.

In other words, it consists of an annular wall which encloses a cavity 19 which is in particular cylindrical.

The holding section 10 is thus deformed by a movement of the ring-shaped wall into the cavity 19 .

Depending on the elasticity of the material, the wall thickness can be thinner or thicker.

In other words, the material may be harder if the wall thickness is thinner, or the wall thickness may be thicker if the material is softer.

The wall thickness is preferably between 3 and 5 mm.

The flap 9 is inserted through the outlet opening 13 of the outlet channel 8 , which is aligned with the opening 12 of the receiving space 11 in order to simplify this.

A pair of pliers, in particular needle-nose pliers, can be used for insertion.

If the flap 9 with the holding section 10 is increasingly pressed against the webs 23, 24, its annular wall deviates inwards into the cavity 19 so that its width is reduced and it can slide past the webs 23, 24 into the receiving space 11 , where the wall relaxes back to its original circular shape.

The flap 9 can also be pulled out of the receiving space 11 again in the same way.

Figures 2 to 4 show the flap 9 according to Figure 1 in front (Fig. 2), side (Fig. 3) and perspective view (Fig. 4). The flap 9 consists of a flap body 18 and the holding section 10. These are cast here in one piece from the same material.

The flap body 18 is tongue-shaped in that of a plate with a flap front 26 and a flap rear 27 which are parallel to each other.

The outer edge area of the front side 26 of the flap and the rear side 27 of the flap form a sealing surface on the flap side in order to come into contact with the respective sealing surface 25 on the side of the pump housing 2 .

The width of the flap body 18 is greater than the axial length of the holding portion 10, so

| that the valve body 18 protrudes axially on both sides with respect to the holding portion 10 Hessie, as FIGS. 2 and 4 illustrate.

FIG. 5 shows a pump housing 2 according to a second embodiment variant of a double pump unit 1 according to the invention. It differs from the first variant essentially in the position and shape of the receiving space 10 and in the shape of the flap 9, which is shown in FIGS.

Furthermore, the suction and pressure ports are formed by flanges.

Although the receiving space 11 according to this second embodiment variant is also symmetrical, it has first and second side wings 21, 22 which are opposite one another with respect to an axis of symmetry 20 and form approximately a heart shape.

The holding section 10 is shaped in such a way that when the first pressure channel 5 is closed it predominantly lies in the second side wing 22 and when the second pressure channel 6 is closed it predominantly lies in the first side wing 21 .

The first pressure channel 5 and the second side wing 22, on the one hand, and the second pressure channel 6 and the first side wing 21, on the other hand, are each on opposite sides of the axis of symmetry 20 of the receiving space 11. The holding section 10, viewed in cross section, has a width (B) that is greater than its height H, see in particular FIG. 7. Overall, the cavity 19 has the cross section of an elongated hole.

Another difference between the flap 9 and the first embodiment variant is that the holding section 10 has the same width as the flap body 18 .

In both embodiment variants, the wall of the receiving space 11 is free of passages to the outside, so that there is no risk of leakage as a result of the flap 9 used.

It should be understood that the foregoing description is given by way of example for purposes of illustration and does not limit the scope of the invention in any way.

Features of the invention classified as "may", "exemplary", "preferred", "optional", "ideal", "advantageous", "if necessary",

"Suitable" or the like are to be considered purely optional and also do not limit the scope of protection, which is defined solely by the claims.

Insofar as elements, components, process steps, values or information are mentioned in the above description which have known, obvious or foreseeable equivalents, these equivalents are also included in the invention.

The invention also includes any changes, alterations or modifications of exemplary embodiments which have the exchange, addition, alteration or omission of elements, components, method steps, values or information as their subject matter, as long as the basic idea according to the invention is retained, regardless of whether the change, alteration, or modifications improves or degrades an embodiment.

Although the above description of the invention mentions a large number of physical, non-physical or procedural features in relation to one or more specific exemplary embodiments, these features can also be used in isolation from the specific exemplary embodiment, at least insofar as they do not necessarily require the presence of further features.

Conversely, these features mentioned in relation to one or more specific exemplary embodiment(s) can be combined as desired with one another and with other disclosed or undisclosed features of exemplary embodiments shown or not shown, at least insofar as the features are not mutually exclusive or lead to technical incompatibilities.

| 12 Reference numerals HU102876 1 Double pump unit 2 Pump housing 3 First pump chamber 4 Second pump chamber First pressure channel 6 Second pressure channel 7 Flap chamber 8 Outlet channel 9 Flap holding section 11 Accommodating space 12 Opening 13 Outlet opening 14 First suction channel Second suction channel 16 Inlet channel 17 Inlet opening 18 Flap body 19 Cavity symmetry axis 21 First side wing 22 Second Side wings 23 First web 24 Second web Sealing surface 26 Flap front 27 Flap rear

Claims (12)

WI 810032 C 6/1/2021 Claims 1. Double pump unit (1) comprising a first and a second centrifugal pump with a common pump housing (2), in which a pump chamber (3, 4) of the first and second centrifugal pump is formed, of which a respective pressure channel (5, 6) in a common flap space (7) which merges into an outlet channel (8) and in which a flap (9) is arranged, which is held pivotably with a holding section (10) in a receiving space (11) of the pump housing (2) and optionally one or the other pressure channel (5, 6) closes, characterized in that the flap (9) is held floating in the receiving space (11) without a shaft. 2. Double pump unit (1) according to claim 1, characterized in that the flap (9) can be pivoted about a variable-position axis and there is play on all sides around the holding section (10). 3. Double pump unit (1) according to claim 1 or 2, characterized in that the receiving space (11) opens towards the flap space (7) via an opening (12) which is narrower than the holding section (10), and that the holding section (11) is so elastic that it can be compressed to a width that is less than or equal to the width of the opening (12). 4. Double pump unit (1) according to claim 3, characterized in that the opening (12) is aligned with the outlet opening (13) of the outlet channel (8). 5. double pump unit (1) according to any one of the preceding claims, characterized in that the holding portion (10) is made of an elastic material. 6. Double pump unit (1) according to one of the preceding claims, characterized in that the holding section (10) is formed by a hollow body, in particular a hollow profile. 7. Double pump unit (1) according to any one of the preceding claims, characterized in that the cross section of the holding portion (10) and the receiving space (11) are each circular. 8. Double pump unit (1) according to one of the preceding claims, characterized in that the holding section (10) has at least a play of 1 mm on all sides. 9. double pump unit (1) according to any one of the preceding claims, characterized in that the receiving space (11) is approximately symmetrical and has a first and second side wings (21, 22), and that the holding portion (10) is shaped such that it Closing of one pressure channel (5) lies at least predominantly in the second side wing (22) and when closing the other pressure channel (6) at least predominantly in the first side wing! (21), wherein the one pressure channel (5) and the second side wing (22) on the one hand and the other pressure channel (6) and the first side wing (21) on the other hand are each on opposite sides of an axis of symmetry (20) of the receiving space (11) condition. 10. Double pump assembly (1) according to any one of the preceding claims, characterized in that the holding portion (10) viewed in cross section has a width (B) which is greater than its height (H). 11.Double pump unit (1) according to any one of the preceding claims, characterized in that the wall of the receiving space (11) is free of passages to the outside. 12. Double pump unit (1) according to any one of the preceding claims, characterized in that the holding portion (10) integral with a one . LU102816 or other valve body (18) closing the pressure channel (5, 6), in particular made in one piece with it.