DOUBLE PUMP WITH INSULATING COVER AND ASSEMBLY PROCEDURE

Description

[0001] The invention relates to a double pump with a pump housing comprising a first housing side with a first pump chamber for the impeller of a first centrifugal pump, and a second housing side with a second pump chamber for the impeller of a second centrifugal pump, wherein the impeller axes of the first and second centrifugal pumps are arranged parallel to one another. Furthermore, the invention relates to a method for assembling an insulating cover for this double pump.

[0002] Pumps of this type are well known, for example from European patent applications EP 2940309 A1, EP 0735273 A1, EP 4098880 A1, or EP 4102076 A1. They are also known as twin pumps due to their identical electric motor drive units, which are flanged to the pump housing with a parallel motor axis and project axially from it. Twin pumps have a wide range of applications. Depending on the application, they can be operated as a main and standby pump (redundant operation), with each pump running individually, or as a base and peak load pump (additional operation), with the pumps operating in parallel. Switching or connecting occurs automatically depending on load or fault.A further advantage is that the double pump acts like a single pump in building automation, so that the installation effort of a double pump is almost identical to that of a single pump, but the application receives two pumps at the same time.

[0003] Double pumps can be used in heating, refrigeration, and / or air conditioning systems, and can therefore pump media that are both warmer and colder than their surroundings. For single pumps in such applications, thermal insulation of the pump housing is common practice. This serves as protection against contact, minimizing the risk of burns from the pump housing in the event of hot media. On the other hand, insulation optimizes efficiency by ensuring that heat is pumped to the consumers rather than dissipated into the environment around the pump housing, and that a cooled liquid does not absorb heat from the environment outside the pump housing. This can also lead to dripping water or even icing on the pump housing, which can be prevented by insulation.

[0004] European patent application EP 1429034 A2 discloses thermal insulation for the pump housing of a single pump. Figure 1 shows a similar thermal insulation for the pump housing of a single pump according to the prior art, comprising two half shells which are placed on the pump housing from opposite sides at right angles to the pump and pipe connection axis and which encompass the pump housing.

[0005] Such insulation is not yet available for a double pump due to its geometry.

[0006] From the French patent application FR 3123704 A1, a thermal insulation covering which can be used for a double pump is known in the form of a flexible bag with several openings through which the centrifugal pumps and connecting pieces extend, wherein a drawstring is incorporated into the seam of each opening in order to attach the covering with the openings to the double pump.

[0007] It is therefore an object of the present invention to provide a double pump with dimensionally stable pump housing insulation that is simple to manufacture and easy to install. Furthermore, it is an object to provide a corresponding assembly method.

[0008] These objects are achieved by a double pump having the features of claim 1 and by a method having the features of claim 15. Advantageous further developments are specified in the subclaims and are explained below.

[0009] According to the invention, an insulating cover surrounds the pump housing of the double pump on all sides, comprising at least one first insulating element which is designed such that it at least partially encompasses the first housing side of the pump housing and is arranged on the pump housing from a first joining direction radially to the impeller axis of the first centrifugal pump, at least one second insulating element which is designed such that it at least partially encompasses the second housing side of the pump housing and is arranged on the pump housing from a second joining direction radially to the impeller axis of the second centrifugal pump, wherein the second joining direction is opposite to the first joining direction, and at least one third insulating element which is designed such that it is arranged on the pump housing from a third joining direction parallel to the impeller axes spatially between a mechanical interface of a drive unit of the first centrifugal pump to the pump housing and a mechanical interface of a drive unit of the second centrifugal pump to the pump housing..

[0010] With the help of this proposed insulating cladding, it is possible to enclose the pump housing of the double pump in a structurally and assembly-wise simple manner or to cover it on all sides and thus to thermally insulate it from the environment as with a single pump. The third insulating element is particularly important here, as it fills the area of ​​the pump housing between the first and second housing sides, more precisely between the first and second centrifugal pumps, axially at approximately the level of the mechanical interface between the pump housing and the drive units of the two centrifugal pumps, which lies behind the respective drive unit from the direction of the first and second joining directions and is therefore not accessible from these directions. From a geographical point of view, the first and second housing sides are to be understood in particular as those areas of the pump housing which, with reference to a central plane, are located between the first and second centrifugal pumps on the right and left.left side of this center plane. The respective first and second housing sides also include the aforementioned mechanical interface between the drive unit of the respective centrifugal pump and the pump housing, which can be formed, for example, by a motor flange on the side of the corresponding drive unit and a corresponding pump head flange on the side of the pump housing, which are screwed together.

[0011] According to the invention, the method comprises the steps a) Arranging the third insulating element of the insulating cladding on the pump housing between the mechanical interface of the drive unit of the first centrifugal pump to the pump housing and the mechanical interface of the drive unit of the second centrifugal pump to the pump housing by axial joining in the direction of the third joining direction parallel to the impeller axes, b) Arranging the first insulating element of the insulating cladding on the pump housing from the first joining direction radially to the impeller axis of the first centrifugal pump such that it is pushed onto the third insulating element and in its final position at least partially encompasses the first housing side of the pump housing, and c) Arranging the second insulating element of the insulating cladding on the pump housing from the second joining direction radially to the impeller axis of the second centrifugal pump such thatthat it is pushed onto the third insulating element and in its final position at least partially encompasses the second housing side of the pump housing, wherein the second joining direction is opposite to the first joining direction.

[0012] It is advantageous if the joining process creates a positive fit between the insulating elements, holding them together. This eliminates the need for additional fasteners that must be manufactured, installed, and possibly disposed of separately. However, if necessary, additional fasteners such as pins, clamps, brackets, hooks, screws, etc. can be used to hold the insulating elements together, provided the positive fit is insufficient in terms of the mechanical strength achieved.

[0013] A key feature of the insulating cladding according to the invention is that it consists of a few, in particular only three, parts, so that assembly effort is minimal. Nevertheless, the first, second, and / or third insulating elements can also be constructed independently of one another in two or more parts, i.e., they can themselves consist of two or more parts, without deviating from the basic concept of the invention.

[0014] For example, the first and / or second insulating elements can each form a half-shell. The half-shell shape is particularly suitable for enclosing the pump housing laterally, as the outer shape of the pump chambers makes it bulbous at the sides. Alternatively, the first and / or second insulating elements can also be composed of two parts, for example, with each part forming a quarter-shell.

[0015] The third insulating element preferably has a central web and a crossbar at each of its ends, so that it has a double-T shape in cross section. This shape is particularly well suited to being arranged between the mechanical interface of the drive unit of the first centrifugal pump to the pump housing and the mechanical interface of the drive unit of the second centrifugal pump to the pump housing. While the central web fills the space between the aforementioned interfaces, the crossbars encompass the interfaces on the top and bottom sides at least partially, preferably up to approximately half of their extension transverse to the impeller axes. Thus, the length of the crossbars in the direction of their longitudinal extension can be at least the length of the central web in the direction of its longitudinal extension. The length of the crossbars preferably corresponds approximately to the distance between the impeller axes.

[0016] The third insulating element is also preferably a single piece. However, it can also be composed of two T-shaped parts or three I-shaped parts.

[0017] The positive connection exists, for example, between the first and third insulating elements on the one hand and between the second and third insulating elements on the other. The first and second insulating elements are therefore each held on the third valve element. A positive connection between the first and second insulating elements on the side of the drive units is therefore not necessary. Further fastening means can also be dispensed with. On the side opposite the drive units, however, a positive connection can exist between the first and second insulating elements, for example by one insulating element encompassing the other insulating element with a protruding outer edge.

[0018] In one embodiment, the positive connection can be formed by at least one groove-bung connection that extends along the first and second joining directions, so that the first and second insulating elements can each be pushed onto the third insulating element from the direction of the first or second joining direction, and once pushed on, the third insulating element can no longer be removed from the connection with the first and second insulating elements. The bung creates an undercut in the groove in the direction of the third joining direction and thus prevents removal of the third insulating element in the direction opposite to the third joining direction. The bung is integral with the crossbeam, so that no additional components form the positive connection.

[0019] Preferably, each of the crossbeams of the third insulating element has a positive connection in the form of a tongue-and-groove connection with the first and second insulating elements. This creates a positive connection on the two axially opposite sides of the central web, so that the third insulating element is firmly held between the first and second insulating elements when the insulating cladding is installed.

[0020] In a preferred embodiment, the bung of the form-fitting connection can be formed by a step-like longitudinal projection which rises in the direction of the longitudinal extent of the central web on at least one of the crossbeams and extends parallel to the longitudinal extent of the crossbeam. In other words, the bung has a height parallel to the longitudinal extent of the central web and a length in the direction of the longitudinal extent of the crossbeam. Thus, the first and second insulating elements can each be pushed onto the third insulating element from one side. In other words, the first and second joining directions are parallel to the longitudinal extent of the crossbeam. Preferably, the step-like longitudinal projection forms a profile on the said crossbeam. This means that it extends continuously along the longitudinal extent of the crossbeam over its entire length. The longitudinal projection orThe cross-section of the bung can basically be of any shape, for example rectangular or dovetail-shaped.

[0021] When assembled, the longitudinal projection or bung extends into a corresponding longitudinal groove, which is formed partly in the first and partly in the second insulating element. The cross-section of the groove corresponds in shape to the cross-section of the bung, but is slightly larger in dimension to ensure smooth joining of the first and second insulating elements. The groove is bounded on one side by a side wall, transverse to its longitudinal extent. Viewed from the third joining direction, the bung engages behind the side wall, so that the side wall prevents the third insulating element from being removed.

[0022] Preferably, a longitudinal projection or bung of the aforementioned type is provided on each of the two crossbeams, in particular mirror-symmetrically to a plane through the longitudinal center of the central web, so that each crossbeam of the third insulating element is positively connected to the first and second insulating elements. This increases the stability of the insulating cladding.

[0023] There are pump housings of double pumps that have two peg-like projections on the rear side facing away from the drive units in order to be supported on a wall. Just like the area between the interfaces of the pump housing and the drive units, the area of ​​the pump housing between the peg-like projections cannot be covered by the first and second insulating elements because, from the perspective of the first and second joining directions, it lies behind the respective peg-like projection. In order to nevertheless enclose the pump housing on all sides, a fourth insulating element can be provided which is arranged on the rear side of the pump housing opposite the third insulating element, in particular between the two peg-like projections. The fourth insulating element can form a positive connection with the first and / or second insulating element and be held in place by the positive connection.For example, it can be essentially I-shaped, T-shaped or double T-shaped as required to allow for easy joining.

[0024] The fourth insulating element can be joined axially, for example, in the direction opposite to the third joining direction. This requires, however, that it is attached to the pump housing before the double pump is mounted on the wall. Since this can be forgotten in practice, it is advantageous if the fourth insulating element can also be placed after the double pump has been mounted on the wall. An I- or T-shaped fourth insulating element is suitable for this purpose and is then joined in a direction perpendicular to the first, second and third joining directions, in particular from above or below. This is preferably done after the first and second insulating elements have been placed on the pump housing, so that the fourth insulating element is pushed between the first and second insulating elements.

[0025] To enable joining of the third insulating element in double pumps in which the distance between the two drive units is narrowed at their end facing away from the pump housing, for example due to a radially protruding electronics housing, the third insulating element can be designed such that the maximum thickness of the central web in the direction transverse to its longitudinal extent and transverse to the longitudinal extent of the crossbeams is equal to or less than the minimum width of the central web in the direction transverse to its longitudinal extent and in the direction of the longitudinal extent of the crossbeams. In short, the central web in this embodiment is narrower than it is wide.This makes it possible to first slide the third insulating element between the drive units rotated by 90° around the longitudinal axis of its central web, then to rotate it back by 90° around the longitudinal axis into the correct orientation and then to attach it to the pump housing in the direction of the third joining direction.

[0026] The insulation elements are ideally made of a foamed plastic, such as expanded polystyrene, to ensure good thermal insulation. They are molded bodies that can be ideally adapted to the outer shape of the pump housing.

[0027] The double pump is preferably a so-called inline pump. This means that the suction and discharge connections of the double pump for the piping are on a common axis.

[0028] Further features, properties, effects, and advantages of the invention are explained in more detail below with reference to exemplary embodiments and the accompanying figures. The reference symbols contained in the figures retain their meaning from figure to figure. In the figures, reference symbols always designate the same or equivalent components, areas, directions, or locations.

[0029] It should be noted that, in the context of this description, the terms "have," "comprise," or "include" in no way exclude the presence of other features. Furthermore, the use of the indefinite article for an object does not preclude its plural.

[0030] The terms "radial" and "axial" used in this description generally refer to a direction parallel to the impeller axes of the centrifugal pumps, unless otherwise stated. Furthermore, the terms "top" refer to the pressure side of the pump, "bottom" to the suction side of the pump, and "front" to the side of the pump housing where the drive units are located, and "rear" to the side of the pump housing facing away from the drive units.

[0031] Features of one embodiment of the invention may also be present in another embodiment, unless this is technically impossible.

[0032] They show: Figure 1: a single pump with mounted insulating cladding according to the prior art Figure 2: exploded view of a part of the single pump with insulating cladding according to the prior art Figure 3: a double pump housing with mounted third insulating element according to the invention Figure 4: a double pump housing with mounted first and third insulating elements according to the invention Figure 5: a double pump housing with mounted first, second and third insulating elements according to the invention

[0033] Figures 1 and 2 show a prior art single pump 1a, usable, for example, as a circulation pump in a heating or cooling system. It comprises a centrifugal pump, an electric motor drive unit 3 driving the centrifugal pump, and pump electronics 4 for controlling and / or regulating the electric motor 3, with these three components being structurally combined. Figure 2 shows in the form of an exploded view some of the components of the single pump 1a.

[0034] The centrifugal pump comprises a pump housing 2 in which a pump chamber 16 is formed. Arranged in the pump chamber 16 is an impeller of the centrifugal pump (not shown here) rotatable about the impeller axis 9. This impeller is attached to a shaft of the drive unit 3 (also omitted here). The centrifugal pump is designed as a wet-running motor pump, meaning that the rotor of the drive unit rotates in the pumped medium.

[0035] Part of the pump housing 2 is a suction channel housing 5 enclosing a suction channel, which connects a suction side of the individual pump 1a with the pump chamber 16, into which it opens axially towards the impeller. The spiral-shaped pump chamber 16 merges tangentially into a pressure channel, which is enclosed by a pressure channel housing 6, which also forms part of the pump housing 2, and opens at a pressure side of the individual pump 1a. On the suction side and pressure side, the pump housing 2 has a flange 7, 8 each for mounting the individual pump 1a in a pipeline. For this purpose, the pump housing 2 is designed in a so-called inline construction, i.e. the inlet area of ​​the suction channel and the outlet area of ​​the pressure channel lie on the same axis 12, see Figure 1Instead of the flanges 7, 8, the individual pump 1a could have threaded connectors. The pump housing 2 further has a pump flange 15 surrounding an opening to the pump chamber, to which a corresponding motor flange 13 of a motor housing of the drive unit 3 is attached by means of screws 14. The pump electronics 4 are mounted on an axial end face of the drive unit.

[0036] The pump housing 2 is enclosed by an insulating cladding, which here consists of two half-shell-shaped insulating elements 10, 20 plugged together, each of which encompasses one side of the pump housing 2. A first insulating element 10 is placed on the pump housing in a first joining direction A radially to the impeller axis 9, and a second insulating element 10 is placed in a second joining direction B radially to the impeller axis 9, wherein the joining directions A, B are opposite.

[0037] Each of the two insulating elements 10, 20, hereinafter also referred to as half-shells 10, 20, has a side body 17, 27 covering the pump housing laterally, which is divided into an upper shell wall 18a, 28a that partially surrounds the pressure channel housing 6, a lower shell wall 18b that partially surrounds the suction channel housing 5, and a rear shell wall 18c, 28c that covers the pump housing 2 on its side facing away from the drive unit 3, and connects the upper shell wall 18a, 28a to the lower shell wall 18b. These rest against one another at the mutually facing end faces 19, 29 of the first and second insulating elements 10, 20. Four pins 11 protrude from the axial end face 19 of the first insulating element 10 and are intended to project into corresponding holes 21 in the axial end face 19 of the second insulating element 10 in order to fasten the two half-shells 10, 20 to one another.

[0038] Figures 3, 4 and 5show an insulating cladding consisting of three insulating elements 10, 20, 30 for a double pump 1 with a pump housing 2 comprising a first housing side 2a with a first pump chamber 16a for the impeller of a first centrifugal pump, and a second housing side 2b with a second pump chamber 16b for the impeller of a second centrifugal pump, wherein the impeller axes 9a, 9b of the first and second centrifugal pumps and thus also the drive units are arranged parallel to one another. Figures 3 to 5only the pump housing 2 without electric motor drive units, so that the view is clear of the pump flange 15a of the first centrifugal pump, which is part of the first housing part 2a, and the pump flange 15b of the second centrifugal pump, which is part of the second housing part 2b. The pump flanges 15a, 15b each form the mechanical interface to the drive unit of the respective centrifugal pump, so that the drive units are flanged to the pump housing 2 with a parallel motor axis and protrude from it in the axial direction. The pump housing 2 is also designed as an inline housing for installation in a pipeline.

[0039] How Figure 5 As can be seen, the insulating cladding according to the invention encompasses the pump housing 2 of the double pump 1 on all sides. In this embodiment, it consists of a first insulating element 10, a second insulating element 20, and a third insulating element 30.

[0040] The first insulating element 10 forms a half-shell and is designed such that it at least partially encompasses the first housing side 2a of the pump housing 2 and is attached to the pump housing 2 from a first joining direction A radially to the impeller axis 9a of the first centrifugal pump on the pump housing, as can be seen from Figure 4 becomes apparent.

[0041] The second insulating element 20 also forms a half-shell and is designed such that it at least partially encompasses the second housing side 2b of the pump housing 2 and is attached to the pump housing 2 from a second joining direction B radially to the impeller axis 9b of the second centrifugal pump, wherein the second joining direction B is opposite to the first joining direction A, as can be seen from Figure 5 becomes clear.

[0042] Finally, the third insulating element 30 is designed such that it is arranged on the pump housing 2 from a third joining direction C, parallel to the impeller axes 9a, 9b, spatially between the mechanical interface 15a of the drive unit of the first centrifugal pump to the pump housing 2 and the mechanical interface 15b of the drive unit of the second centrifugal pump to the pump housing 2. The third insulating element 30 fills the area of ​​the pump housing 2 between the first and second housing sides 2a, 2b, more precisely between the first and second centrifugal pumps, axially approximately at the level of the pump flanges 15a, 15b, which lies behind the respective drive unit from the direction of the first joining direction A and the second joining direction B and is therefore not accessible from these directions. The pump housing 2 is thus covered on all sides, with the third insulating element 30 acting as an intermediate piece or central part.

[0043] As the comparison of the Figures 3, 4 and 5 with each other, the third insulating element 30 is first attached to the pump housing 2, followed by the first insulating element 10 and then the second insulating element 20. However, instead of the first insulating element, the second insulating element could also be mounted first and then the first insulating element. The sequence is determined by a positive connection that exists between the first insulating element 10 and the third insulating element 30 as well as between the second insulating element 20 and the third insulating element 30 and which holds the insulating elements 10, 20, 30 together without the need for additional fastening means. If necessary, however, additional fastening means, such as the pins 11 in Figure 2 , are used to hold the first and second insulating elements 10, 20 together.

[0044] How Figures 3 to 5As shown, the third insulating element 30 has a double-T-shaped cross-section. It consists of a central web 31 and two crossbeams 32, 33, between which the central web 31 extends. It should be noted that the central web 31 and the crossbeams 32, 33 merely form sections of the third insulating element 30, which is thus a single piece. Nevertheless, in another embodiment, the third insulating element 30 could be composed of subcomponents, such as two T-shaped or three I-shaped components.

[0045] While the central web 31 fills the space between the pump flanges 15a, 15b, the crossbeams 32, 33 encompass the pump flanges 15a, 15b on the top and bottom sides approximately up to their center relative to their extension transverse to the impeller axes 9a, 9b, or in other words up to the height of the respective impeller axis 9a, 9b, where the first and second insulating elements 10, 20 then adjoin, each of which encompasses the remaining part of the corresponding pump flange 15a, 15b. The length LQ of the crossbeams 32, 33 in the direction of their longitudinal extension thus corresponds approximately to the distance between the impeller axes 9a, 9b.

[0046] The maximum thickness of the central web 31 in the direction transverse to its longitudinal extent and transverse to the longitudinal extent of the crossbeams 32, 33 is less than the minimum width B min of the central web 31 in the direction transverse to its longitudinal extent and in the direction of the longitudinal extent of the crossbeams 32, 33, so that the central web 31 is narrower than it is wide. This enables installation of the third insulating element 30 in confined spaces at the insertion end into the area between the drive units. Thus, the third insulating element 30 can first be rotated 90° about the longitudinal axis of its central web 31 and pushed between the drive units. It is then rotated back 90° about the longitudinal axis into the correct orientation before being attached to the pump housing 2 in the direction of the third joining direction C.

[0047] The positive connection between the first insulating element 10 and the third insulating element 30 as well as between the second insulating element 20 and the third insulating element 30 is formed by a first tongue and groove connection between the upper crossbeam 32 and the first insulating element 10 and the third insulating element 30, and by a second tongue and groove connection between the lower crossbeam 33 and the first insulating element 10 and the third insulating element 30. For this purpose, each of the crossbeams 32, 33 has a stepped recess 34 on its front longitudinal edge. This recess forms a profiled, stepped longitudinal projection 35 which rises in the direction of the longitudinal extent of the central web 31 on each of the two crossbeams 32, 33 and extends parallel to the longitudinal extent of the respective crossbeam 32, 33. This respective longitudinal projection 35 forms the bung of the respective groove-bung connection.It is rectangular in cross-section and, when the insulation elements 10, 20, 30 are mounted, projects into a corresponding longitudinal groove 25 which is provided in the upper shell wall 18a and in the lower shell wall 18b of the first and second insulation elements 10, 20, see . Figure 4 , whereby only the first insulating element 10 is shown here. The respective longitudinal groove 25 is delimited to the front, more precisely to one side transverse to its longitudinal extent, by a side wall 24, which in turn engages in the corresponding, previously mentioned recess 34.

[0048] Thus, the first and second insulating elements 10, 20 can each be pushed onto the third insulating element 30 from one side, since the first and second joining directions A, B are parallel to the longitudinal extent of the crossbeam. Viewed from the third joining direction C, the bung 35 on the upper and lower crossbeams 32, 33 consequently engages behind the side wall 24, which forms an undercut, thus preventing the removal of the third insulating element 30 from the form-fit connection. When the insulating cladding is installed, the third insulating element is thus firmly held between the first and second insulating elements without the need for additional fastening means.

[0049] Also on the Figures 3 to 5A positive connection between the first and second insulating elements 10, 20 can be provided on the non-visible rear side of the pump housing, for example, such that the rear shell wall 18c, 28c of one of the two insulating elements 10, 20 has a projecting outer edge that positively engages a recess in the outer edge of the opposite insulating element. Alternatively or in addition to the rear positive connection, additional fastening means, such as pins 11 in Figure 2 , can be used to connect the first and second insulating elements 10, 20 together.

[0050] An essential feature of the insulating cladding 10, 20, 30 according to the invention is that it consists of a small number of parts, as in this example, only three parts. However, the first, second, and / or third insulating elements 10, 20, 30 can also be constructed independently of one another in two or more parts, i.e., they can themselves consist of two or more parts, without deviating from the basic concept of the invention.

[0051] Furthermore, in another embodiment variant, a fourth insulating element can cover a point on the pump housing that cannot be covered by the first or second insulating element 10, 20 because, for example, from the perspective of the first or second joining direction A, B, it is located behind a projecting section of the pump housing 2, for example on the rear side of the pump housing 2 facing away from the drive units. The fourth insulating element can also form a positive connection with the first and / or second insulating element 10, 20 and be held above it. Depending on requirements, it can, for example, be essentially I-shaped, T-shaped or double T-shaped to enable easy joining. The insulating elements are made of expanded polystyrene to ensure good thermal insulation. They are molded bodies that are adapted to the external shape of the pump housing.

[0052] It should be understood that the foregoing description is given merely by way of example for illustrative purposes and in no way limits the scope of the invention. The scope of protection is defined solely by the following claims. List of reference symbols

[0053] 1Double pump 1aSingle pump 2Pump housing 2aLeft pump housing 2bRight pump housing 3Electric motor 4Pump electronics 5Suction channel housing 6Discharge channel housing 7Suction side flange 8Discharge side flange 9Impeller axle 9aImpeller axle of the first centrifugal pump 9bImpeller axle of the second centrifugal pump 10First insulating element, half-shell 11Fixing pins 12Pipe connection axle 13Motor flange 14Screws 15Pump flange 15aPump flange of the first centrifugal pump, mechanical interface 15bPump flange of the second centrifugal pump, mechanical interface 16Pump chamber 16aPump chamber of the second centrifugal pump 16bPump chamber of the second centrifugal pump 17Side body 18aUpper shell wall 18bLower shell wall 18cRear Shell wall 19End face 20Second insulating element,Half shell 21 Holes 22 Free 23 Free 24 Side wall 25 Groove 26 Free 27 Side body 28 Upper shell wall 28 Lower shell wall 28 Rear shell wall 29 End face 30 Third insulating element 31 Central web 32 Upper crossbeam 33 Lower crossbeam 34 Recess 35 Bung, longitudinal projection,

Claims

1. Double pump (1) with a pump casing (2) comprising a first casing side (2a) with a first pump chamber (16a) for the impeller of a first centrifugal pump and a second casing side (2b) with a second pump chamber (16b) for the impeller of a second centrifugal pump, in which the impeller axes (9a, 9b) of the first and second centrifugal pumps lie parallel next to each other and an insulating lining (10, 20, 30) encompasses the pump casing (2), characterised by the insulating lining (10, 20, 30) comprising - at least one first insulating element (10) that is formed to at least partly encompass the first casing side (2a) of the pump casing (2) and, from a first assembly direction (A), is arranged on the pump casing (2) radially to the impeller axis (9a) of the first centrifugal pump, - at least one second insulating element (20) that is formed to at least partly encompass the second casing side (2b) of the pump casing (2) and, from a second assembly direction (B), is arranged on the pump casing (2) radially to the impeller axis (9b) of the second centrifugal pump, in which the second assembly direction (B) is opposite to the first assembly direction (A), and - at least one third insulating element (30) that is formed so that, from a third assembly direction (C) that is parallel to the impeller axes (9a, 9b), it is spatially arranged on the pump casing (2) between a mechanical interface (15a) of a drive unit of the first centrifugal pump to the pump casing (2) and a mechanical interface (15b) of a drive unit of the second centrifugal pump to the pump casing (2).

2. Double pump (1) according to claim 1, characterised by the existence of a positive fit between the insulating elements (10, 20, 30) as a result of assembly so that they are held together.

3. Double pump (1) according to claim 1 or 2, characterised by the first and / or second insulating element (10, 20) respectively forming a half shell.

4. Double pump (1) according to claim 1, 2 or 3, characterised by the third insulating element (30) having a central web (31) and, at its end, respectively a crossbar (32, 33), so that its cross-section is a double-T shape.

5. Double pump (1) at least according to claim 2, characterised by the existence of the positive fit between the first and third insulating element (10, 30) on the one hand and between the second and third insulating element (20, 30) on the other hand.

6. Double pump (1) at least according to claim 2, characterised by the positive fit being formed by at least one tongue and groove joint (25, 35) extending along the first and second assembly direction (A, B) so that the first and second insulating elements (10, 20), respectively, can slide onto the third insulating element (30) and, after sliding onto the third insulating element (30), can no longer be removed from the combination with the first and second insulating elements (10, 20).

7. Double pump (1) at least according to claim 4, characterised by each of the crossbars (32, 33) of the third insulating element (30) having a positive fit in the form of a tongue and groove joint (25, 35) with the first and second insulating elements (10, 20).

8. Double pump (1) according to claim 6 or 7, characterised by the tongue (35) of the tongue and groove joint (25, 35) being formed by a steplike longitudinal projection which, in the direction of the longitudinal extent of the central web (31), rises on at least one of the crossbars (32, 33) and extends parallel to the longitudinal extent of the crossbar (32, 33) so that, in the assembled state, it projects into a corresponding longitudinal groove (25) that is formed in part in the first and in part in the second insulating element (10, 20).

9. Double pump (1) according to one of the preceding claims, characterised by the first, second and / or third insulating element (10, 20, 30) comprising two or more parts.

10. Double pump (1) according to one of the preceding claims, characterised by a fourth insulating element that is arranged on the side of the pump casing (2) opposite to the third insulating element (30).

11. Double pump (1) at least according to claim 4, characterised by the maximum thickness of the central web (31) in the direction crosswise to its longitudinal extent and crosswise to the longitudinal extent of the crossbars (32, 33) being equal to or less than the minimum width of the central web (31) in the direction crosswise to its longitudinal extent and in the direction of the longitudinal extent of the crossbars (32, 33).

12. Double pump (1) at least according to claim 4, characterised by the length of the crossbars (32, 33) in the direction of their longitudinal extent being no less than the length of the central web (31) in the direction of its longitudinal extent.

13. Double pump (1) according to one of the preceding claims, characterised by the insulating elements (10, 20, 30) being made of foamed plastic.

14. Double pump (1) according to one of the preceding claims, characterised by being an inline pump.

15. Method for the assembly of an insulating lining (10, 20, 30) for a double pump (1) with a pump casing (2) comprising a first casing side (2a) with a first pump chamber (16a) for the impeller of a first centrifugal pump and a second casing side (2b) with a second pump chamber (16b) for the impeller of a second centrifugal pump, in which the impeller axes (9a, 9b) of the first and second centrifugal pump lie parallel next to each other, characterised by the steps of a) arranging a third insulating element (30) of the insulating lining (10, 20, 30) on the pump casing (2) between a mechanical interface (15a) of a drive unit of the first centrifugal pump to the pump casing (2) and a mechanical interface (15b) of a drive unit of the second centrifugal pump to the pump casing (2) through axial assembly in a third assembly direction (C) lying parallel to the impeller axes (9a, 9b), b) arranging a first insulating element (10) of the insulating lining (10, 20, 30) on the pump casing (2) from a first assembly direction (A) radial to the impeller axis (9a) of the first centrifugal pump so that it slides onto the third insulating element (30) and, in its final position, at least partly encompasses the first casing side (2a) of the pump casing (2), and c) arranging a second insulating element (20) of the insulating lining (10, 20, 30) on the pump casing (2) from a second assembly direction (B) radial to the impeller axis (9b) of the second centrifugal pump so that it slides onto the third insulating element (30) and, in its final position, at least partly encompasses the second casing side (2b) of the pump casing (2), in which the second assembly direction (B) is opposite to the first assembly direction (A).