EP0911528A1 - Impeller made of sheet metal - Google Patents

Abstract

At least the base plate (2) and blades (4) are formed from stainless steel plate. Each blade comprises a bent surface on which at least two tabs (11,12) are formed. The tabs fit in depressions (5,6) or slots in the base plate and the inlet connection (3) or cover plate. Preferably each tab is bent out of the plane of the blade surface.

Description

The invention relates to an impeller for a centrifugal pump, the consists of several parts, the axis of the Pump motor receiving hub a rear base plate is attached, on which several blades conveying the medium are arranged, which are a front intake manifold or a Wear the front cover plate with a suction opening. The The invention further relates to a method of manufacture such multi-part impellers.

Such impellers for centrifugal pumps are usually made of Injection molded plastic because this method is a is a very simple procedure, with the varied Impeller designs can be realized. This Plastic impellers, however, show especially when They promote hot media with temperatures around 100 degrees Celsius or more are used in the long run increased wear and poor dimensional stability.

For high-temperature applications, therefore, you are giving way more and more on metallic impellers made from design-related Reasons can also be made from several sheet metal parts can then be welded together.

In particular, the Blade surfaces are individually formed from sheet metal and individually over its full length with the load-bearing elements of the Impeller welded. Here it happens that the Impeller due to the large heat flow that occurs during welding occurs between the individual parts, very badly deformed, which affects the concentricity. Therefore it is often necessary to retrofit a wheel made in this way to judge.

It is also often disruptive in the form of Flow noise and loss of power noticeable, if there are strong weld seams Turbulence in the pumped medium can occur.

A metallic impeller with many welds is also one of the specialty welded joints exposed to excessive corrosion, especially then is increased when corrosive media such as chemicals are conveyed should be. In such a case, show such welded impellers made of normal sheet a clearly reduced lifespan.

An impeller of this type is e.g. from FR 0 153 221 known. One version of this impeller consists of a metallic base plate to which several blade surfaces are welded on. Each of the blade surfaces contributes to the Intake manifold facing top several protrusions via a clamping effect with corresponding recesses on the Bottom of the intake manifold are connected.

The object of the invention is an impeller of the beginning mentioned type and a manufacturing process for such Improve impellers so that the impeller temperature and is corrosion-resistant and due to its design features simple, inexpensive and true to shape is. Furthermore, the remaining disadvantages mentioned above be overcome.

The solution to the problem is an impeller of the beginning to create the type mentioned, in which at least the base plate and the blades made of sheet metal, especially stainless steel sheet are shaped, and each blade is one in itself, i.e. spatially curved surface forms at least at an angle two tab-shaped surface sections (tabs) are formed, which in impressions and / or slots of the base plate and Insert the intake socket or the cover plate. The task is further solved in that the individual parts Sheet metal, in particular made of stainless steel sheet, the by resistance welding, in particular by short-term resistance welding be connected to each other.

Here, several can be carried out in a particularly simple manner interconnected blades in one step the base plate and / or the intake manifold / the cover plate welded or otherwise connected.

In addition to the use of sheet metal that the temperature resistance of the impeller secures when using Stainless steel sheet the additional advantage that the Corrosion resistance is significantly improved.

The flap-shaped surfaces formed on the blade Surface sections serve as a connecting element to the Buckets both on the base plate and on the To fix the intake manifold or the cover plate at certain points. There is only a connection through these tabs / tabs between base plate and the intake manifold or the Cover plate. The rags / tabs are the only one Element where the spot welding takes place. This has the advantage that only a few areas of the Impeller are exposed to a heat flow by welding, whereby the dimensional stability of the Impeller remains guaranteed.

For assembly, it is advantageous if each tab / everyone Surface section bent from the plane of the blade surface is. Here, each tab can be essentially parallel to an imprint in the base plate and / or Suction nozzle / cover plate.

The embossments are provided to prevent through those on the base plate and the intake manifold or the Cover plate overlapping rag of the vortices of the pumped medium. It is also possible that the lobes of the blades in addition or exclusively in Slots are attached.

Each forms a further feature essential to the invention Blade area is a curved area, i.e. that a Bucket area not only in one dimension, i.e. around that Axis of rotation of the hub, but also perpendicular to it and thus bent around its normal in a further dimension.

The hub of the drive axle intended for Impeller is preferably designed such that it Shape of a pot with an end face on the bottom has whose wall in at least three sections has moved in. Here it is found to be very helpful that the pot shape of the hub by simple forming techniques, such as e.g. Thermoforming can be made. The three-part Fit to the axis makes it easier Assembly process, the seat breaks a better Allow system compensation between axis and hub.

From a welding point of view, it is also recommended that with the hub of the impeller on the front An annular projection is integrally formed on the bottom surface is. This results in the transition point between Hub and base plate are circular Welded connection, so that even at this point only one low heat flow is required for welding, whereby distortion of the workpiece during welding is prevented.

In another preferred embodiment of the hub it is provided that on the side facing away from the bottom surface Flange is formed, which is in the case of the axis pressing Assembly support is used so that a force on the Wheel center is avoided.

The base plate to be attached to the hub, which the Forms the basis for all parts of the impeller, points a central bulge, which is also used as an investment and Sealing surface for the blade surfaces is used. Such Construction is particularly simple thanks to deep-drawing techniques producible.

Because the intended for fastening the blade surfaces Flaps / tabs of the individual blade surfaces in impressions should, as mentioned above, entangle the To prevent the medium, it makes sense that the Base plate these impressions and / or slots in one outer area, i.e. preferably at the edge of the plate, has, since these marginal areas in the production by Welding tools are easy to reach. The number of Embossing is on the number of blades Voted.

Typically 8 blades are provided. But there are also significantly fewer or more blades possible.

The suction side of the impeller can be changed easily Cover plate with a central hole or e.g. also be formed by an intake manifold. Here, the Intake port preferred from a design point of view the shape of a cylinder, at the end of which an annular Flange is formed, which is to accommodate the tabs / tabs of the serves individual blade surfaces. It is accordingly advantageous here that the annular flange of the nozzle a number of impressions corresponding to the number of blades and / or has slots, these additionally in the middle Have surveys, usually as weld nipples be designated.

These elevations cause the rag to be welded of the blade surfaces only touch the flange. This will result in a significant reduction in the welding current enables what a beneficial effect less Brings heat flow with it. In another advantageous Design is the flange of the intake manifold opposite outer lateral surface arranged at an obtuse angle.

In one embodiment of the impeller, it is possible that the Don't shovel each one with the base plate and that Intake manifold is connected, but that they are in one piece with the base plate, an additional plate, a front plate Cover plate and / or is connected to the intake manifold. At The easiest alternative to manufacture is conceivable that all blades are formed from a sheet metal surface, whereby the sheet surface as such is connected to the base plate.

Individual welds of the blade can be made here remain under.

The manufacture of the impeller according to the invention is based on how already mentioned above, on a process in which the individual parts made of sheet metal, especially stainless steel sheet are produced, these parts by Resistance welding, preferably by short-term resistance welding be connected to each other.

By using this welding technique can be avoided be that whole welds to connect the individual Parts need to be pulled, which automatically results in a high Heat flow would be generated. Rather, with this technique the parts to be connected only selectively welded. This can further reduce the heat flow when the short-term resistance welding is preferred is applied.

In the method according to the invention, the base material for every single part cut from flat sheet metal and / or punched and shaped into the final shape. In addition to the standard punching technology, it is e.g. also possible to cut the sheets laser cutting machines too use.

The forming parameters should always be selected so that the stresses arising from the design are as low as are possible to prevent material damage. Is also make sure that after cutting / punching none Burr-forming edges face outward to include a Avoid risk of injury to people who on Manufacturing processes are involved.

After shaping and before welding the parts the hub, the base plate and the intake manifold or Cover plate by cutting and / or punching the surrounding remaining sheet metal separately. On the other hand, they stay individual blades until after welding through the surrounding sheet metal interconnected.

This means that the work can be carried out with one another connected blades with the base plate and / or the Intake connectors are welded. Only after welding the blades are separated from the piece of sheet metal connecting them, e.g. separated from a ring.

The shape of the hub is preferred Process steps in that first a pot shape the flat sheet is formed. This can e.g. through a or several deep-drawing work steps. In one Another step, which is a Extrusion can act, the annular Projection shaped at the bottom of the hub. Here is special to ensure that there is enough material to the To perform forming. Otherwise one could Result in structural damage. In another step the jacket wall becomes an at least three-part fit retracted for the axle, which is then taken up for inclusion the axis is calibrated. It is worth noting that the work steps in a different order can be executed.

The hub is, as already mentioned, after the shaping measures separated from the rest of the surrounding sheet metal. Here, the Separation should be carried out so that there is a flange on the hub remains, which serves as an assembly support in the pressing of the Axis serves.

The base plate is preferably made in that first into a round basic shape of the flat sheet central bulge is formed. This bulge can be in simply e.g. by single or multiple deep drawing will be realized. In another step, in one annular area that the outer edge of the base plate forms a number of corresponding to the number of blades Imprints and / or slots introduced to accommodate serve the tabs of the blade surfaces.

For the manufacture of the blades, this is advantageously done proceed that the sheet material for a certain number, especially for all blade surfaces of the impeller cut contiguously from a sheet metal surface or punched and then formed into the blade surfaces. This has the advantage that all or at least a large number surfaces of die cut simultaneously and then punched can also be edited at the same time. Especially it is practical that the blade surfaces during the Processing all connected e.g. by an outside Sheet metal ring are interconnected. Flat the blade are then welded all at the same time or successively connected to the base plate and first then separated from each other. This procedure has the Advantage of having a large number of blades, ideally all blades at the same time on the base plate Attachment can be aligned.

In some preferred steps, the Blade surfaces manufactured so that first the basic shape of the Cut out surfaces from flat sheet metal, in particular is punched out. In a further step, the rags, that are used to attach the intake manifold. In Another step will be the blade surfaces in itself bent. This can be done in particular by beads. The Areas that form the outlet openings of the impeller are cut free in another step, especially punched out. After that, the blade surfaces on the tab, through which there is still a connection between the individual Blade surfaces exist among each other and those for attachment serves on the base plate, superscript.

The shape of the intake manifold takes place in that First a pot-shaped depression in the flat sheet is formed, on the side facing away from the bottom of the pot cylindrical mantle that extends through the molded recess results in a flange-shaped surface remaining. The Shaping takes place e.g. in a simple way by deep drawing. In a further step, the bottom of the pot becomes one Cut out or punched out collar. Then the Collar put through and at the same time or in time Order the flange surface at an angle to the jacket employed. In another step, the flange surface a number of impressions corresponding to the bucket number pressed in, their shape corresponding to the lobes of the blades are trained and in the middle of additional surveys be pressed in via the spot weld is made.

After welding the individual parts as mentioned in preferably by short-term resistance welding the surface of the finished impeller, additionally protected by a paint. At this Painting can be a cataphoretic painting act. If for the manufacture of the impeller stainless steel such a coating is not necessary.

An embodiment of the impeller according to the invention and the method of manufacture is in the drawings shown and is described in more detail below. The Drawings have different scales among themselves.

Fig. 1A

einen Schnitt durch ein erfindungsgemäßes Laufrad,

Fig. 1B

eine Aufsicht im Detail auf die Austrittsöffnungen des Laufrades,

Fig. 2

Schnittansichten der Nabe eines erfindungsgemäßen Laufrades,

Fig. 3

Schnittansichten des Ansaugstutzens eines erfindungsgemäßen Laufrades,

Fig. 4

einen Schnitt durch die Grundplatte eines erfindungsgemäßen Laufrades

Fig. 5

eine skizzierte Aufteilung eines ebenen Bleches für die Anordnung der Schaufelflächen mit verschiedenen Aufteilungsmöglichkeiten

Fig. 6

mehrere symbolisierte Verfahrensschritte zur Herstellung der Nabe eines erfindungsgemäßen Laufrades

Fig. 7

mehrere symbolisierte Verfahrensschritte zur Herstellung der Grundplatte eines erfindungsgemäßen Laufrades

Fig. 8

mehrere symbolisierte Verfahrensschritte zur Herstellung des Ansaugstutzens eines erfindungsgemäßen Laufrades

Fig. 9

mehrere symbolisierte Verfahrensschritte zur Herstellung der Schaufelflächen eines erfindungsgemäßen Laufrades

Fig. 10

Darstellung der aus einem Blech zur Bildung der Schaufeln auszustanzenden Bereiche

Fig. 11

eine alternative Blechaufteilung mit angedeuteten Schaufelflächen.

Show it:

Fig. 1A

a section through an impeller according to the invention,

Figure 1B

a detailed view of the outlet openings of the impeller,

Fig. 2

Sectional views of the hub of an impeller according to the invention,

Fig. 3

Sectional views of the intake manifold of an impeller according to the invention,

Fig. 4

a section through the base plate of an impeller according to the invention

Fig. 5

a sketched division of a flat sheet for the arrangement of the blade surfaces with different division options

Fig. 6

several symbolized process steps for producing the hub of an impeller according to the invention

Fig. 7

several symbolized method steps for producing the base plate of an impeller according to the invention

Fig. 8

several symbolized process steps for producing the intake manifold of an impeller according to the invention

Fig. 9

several symbolized method steps for producing the blade surfaces of an impeller according to the invention

Fig. 10

Representation of the areas to be punched out of a sheet metal to form the blades

Fig. 11

an alternative sheet metal division with indicated blade areas.

Figure 1A shows a sectional view of the basic structure of an impeller according to the invention Sheet. The hub 1 is at the location of the projection 7 connected to a base plate 2, which has a central bulge 10 has and as a contact surface for the blade surface edges serves.

Figure lB, which is a closer view of the The outlet openings of the impeller shows that the Blade surfaces 4 with a tab-shaped surface section 11 in an impression 5 of the base plate and with the other lobe-shaped section 12 in an impression 6 of Insert intake manifold 3. This figure also shows that the tabs / tabs 11 and 12 directly at an angle the blade surfaces 4 are formed. The blade surface 4 itself extends in the area between base plate 2 and the intake manifold 3. The connection between the Intake 3 and the base plate 2 takes place in this Example only on the tabs 11 and 12 of the Blade areas 4. It cannot be seen in detail here that the blade surface 4 in itself, i.e. is spatially curved, the bend of the blade surface on the one hand around the Axis of rotation of the hub 1 and on the other hand perpendicular to this, what a tilting of the end face (4a) of the blade surface (4) to the axis of rotation.

Figure 1A also shows an alternative Embodiment of the hub in which a flange 8 is molded to serve as an assembly support.

The hub 1 of the impeller according to the invention is in the Figure 2 shown in detail. The lower part of the Figure 2 shows the hub 1 in a side Sectional view. The hub shown is in the shape of a pot with an end face 13 on which a annular projection 7 is integrally formed. This The connection point at the base plate forms a projection 2 is welded to the hub. In the circle shown is reproduced the alternative embodiment of the hub at the flange 8 mentioned above directly to that of the bottom surface 13 facing away from the hub 1 is formed.

A bottom view is in the upper part of Figure 2 shown. The wall 14 of the hub is in three sections 9 moved in to get a good investment balance for the to form the axis of the drive motor to be pressed. In the right Again, part of this illustration is the alternative form of Hub shown with the flange 8.

Figure 3 shows the intake 3 of the impeller according to the invention. This essentially has that Shape of a cylinder at one end an annular Flange 15 is formed, which is based on the outer Shell surface is arranged at an obtuse angle.

Furthermore, this flange 15 has one of the number of blades corresponding number of impressions 6, for reasons of Clarity not all are shown here. Each These impressions have a central one as a welding aid Survey 17 on.

The base plate 2 of the impeller is shown in Figure 4 shown. In addition to a central bulge 10, it points on outer edge of a number corresponding to the bucket number Imprints 5, which for receiving the tabs 11 of the Serve blade surfaces. These impressions can as well the impressions 6 of the intake manifold 3 central elevations exhibit. These surveys are not in the figure shown.

In Figure 5, the division is in a hand sketch a flat sheet is shown in several blade surfaces. The upper half of Figure 5 shows the distribution a circular sheet in 4 equal sized sectors over one Angles of α = 45 degrees each. With such a division it is possible to make 8 display surfaces from one sheet at the same time to cut or punch. A possible form of Blade areas 4 are indicated in three of the upper sectors. Will, as in the lower part of the figure in the central sector shown, the sheet in only 6 equal sectors each β = 60 degrees, so only 6 can do it from the sheet larger blade areas 4 are cut out and shaped. The size and number of the desired blade areas 4 depends from external predetermined parameters.

Each blade surface 4 has two tab-shaped surface sections or tabs 11 and 12. These tabs are finished with the shaped blade each on a bending edge which is in this Embodiment under  = 30 degrees to the radial Sector boundary runs, bent from the blade surface. It is also possible in other versions, the bending edge under to run another angle . With the finished impeller is the tab 11 in the corresponding impression 5 of the Base plate 2 and the tab 12 in the impression 6 of the Intake 3.

Figure 5 shows only the arrangement of the blade surfaces on the sheet and a basic shape of the surfaces. In the curved shape of the finished blade can flatten cannot be taken from this illustration.

This is an embodiment of the manufacturing process given that the individual parts e.g. made of stainless steel sheet getting produced. This is done so that the parts after shaping by resistance welding to each other get connected.

Before shaping, the basic material is made for each one Part, i.e. for the hub, base plate, blades and intake manifold punched out of flat sheet metal. During the punching process, it is on ensured that no burr-forming edges on the individual Parts arise. After shaping, hub 1, Base plate 2 and intake manifold 3 from the rest surrounding sheet metal separately. Only the blade surfaces 4, which are still connected to each other after the shaping, are first welded to the base plate 2 and then separated from each other.

Figure 6 shows an explanatory overview individual work steps Ia - VIa for producing a hub for the impeller according to the invention. In a first step Ia As mentioned above, the base material for the hub is made from the flat sheet metal punched out. Then over two Thermoforming steps IIa and IIIa the pot shape of the hub 1 from the flat sheet formed. In the work step IVa a compression of the bottom of the pot of the annular projection 7 Shaped hub. After that, the shell wall of the hub in the crotch Va to a fit for the axis in three sections 9 retracted and calibrated around an axis with large To be able to record fit. In step VIa Completely molded hub through from the surrounding rest of the sheet another die cut separately. This is done so that at the Hub the above flange to simplify assembly stop.

Process steps Ib-Vb for the production of the base plate 2 are explained in more detail by Figure 7. Here too in a first step Ib the basic material for the Base plate 2 punched out of the flat sheet. In two Thermoforming steps IIb and IIIb then become the middle one Bulge shaped into the basic shape of the sheet. In connection in step IVb the edge of the so shaped is then Base plate 2 provided with several embossings 5, which for Serve receiving the tabs 11 of the blades 4. The number of Impressions correspond to the number of blades. in the last step Vb is the molded base plate 2 from the surrounding rest of the sheet separately.

Figure 8 shows the process steps Ic - VIc Production of the intake manifold 3. In the first step Ic the base material is also made for the intake manifold punched out of the sheet. In the second step IIc Deep-drawing work step into a pot-shaped depression Sheet metal drawn, on the side facing away from the bottom of the pot a flange-shaped surface remains. In step IIIc the bottom of the pot is then punched out to a collar 16, after which this is put through in step IVc. Right away then the flange surface in at an angle to the coat. In the procedural step Vc becomes one of the number of blades in the surface of the flange corresponding number of impressions 6 and in the middle one elevation 17 each is pressed in. In the last step VIc is also the intake manifold 3 from the rest of the sheet separated out.

The sheet material is used to produce the blade surfaces 4 for all blade surfaces connected together from a sheet metal surface punched out and then in this contiguous Formed into the final blade surfaces 4. Only after welding to the base plate then becomes the individual Blade surfaces separated from each other. Steps Id - VIId to produce these blade surfaces illustrate the Figures 9 and 10. In the first step Id from the Base material of the sheet which is shown in Figure 10 with A and B designated areas punched out. In the next step IId the areas C are punched out of the sheet. In connection this is followed in step IIId, the tabs 12, which are used Attachment of the intake manifold 3 serve, from the sheet metal level bent out. In step IVd, the individual Blade surfaces 4 bent in itself. This bending is done by Beads. This is followed by another step Vd Punch out the areas D that the edge of the later Form outlet openings of the impeller. Following this the blades on the one shown in Figure 5 Angle of  = 30 degrees shown bending edge raised.

After all the punching and forming steps, they hang single blade surfaces 4 still above that in the Figure 10 border area shown in dashed lines together. Accordingly, all can in a subsequent process step Blade surfaces 4 simultaneously on the base plate 2 aligned and welded to it. Only in The individual are then connected to this weld Blade surfaces 4 separated from the edge area. Following on the hub 1 to the base plate 2 and the intake manifold 3 to the tabs 12 of the blade surfaces 4 provided for this welded on.

Figure 11 also shows another alternative, the sheet into several areas for the blade surfaces 4 to divide. Is it e.g. provided the impeller as in in this case, with 8 slightly larger blade areas equip, it is striking that some areas of the Display areas 4 would overlap on the sheet. Accordingly, in this case the sheet for 4 contiguous blade surfaces are punched out and machined, as described above. The corresponding division on the Sheet metal is shown in Figure 11 by continuous lines shown. After shaping, the first 4 finished blade areas on the base plate welded. The process is then followed by a repeated another sheet for the second 4 blade surfaces, which is then also offset by a division on the Base plate 2 are attached. This procedure is also for any other number of blade areas divisible, each time a certain number of Blade surfaces 4 simultaneously on the base plate 2 aligned and welded to it.

Claims (24)

Impeller for a centrifugal pump, which consists of several parts, with a rear base plate (2) attached to a hub (1) receiving the axis of the pump motor, on which a plurality of blades (4) conveying the medium are arranged, which have a front intake port ( 3) or carry a front cover plate with a suction opening, characterized in that at least the base plate (2) and the blades (4) are formed from sheet metal, in particular from stainless steel sheet, and each blade (4) forms a curved surface, to which at least two tab-shaped surface sections / tabs (11, 12) are formed at an angle, which lie in impressions (5, 6) and / or slots in the base plate (2) and the suction connector (3) or the cover plate. Impeller according to claim 1, characterized in that each tab / surface section is bent out of the plane of the blade surface. Impeller according to one of the preceding claims, characterized in that each tab / each surface section lies essentially parallel to an embossing in the base plate and / or the intake port / the cover plate. Impeller according to one of the preceding claims, characterized in that the hub (1) of the impeller has the shape of a pot with an end face (13), the wall (14) of which is drawn in in at least three sections (9). Impeller according to one of the preceding claims, characterized in that in the case of the hub (1) of the impeller, an annular projection (7) is integrally formed on the end face surface (13). Impeller according to one of the preceding claims, characterized in that a flange (8) is formed on the hub (1) of the impeller on the side of the pot facing away from the base surface (13). Impeller according to one of the preceding claims, characterized in that the base plate (2) attached to the hub (1) has a central bulge (10). Impeller according to one of the preceding claims, characterized in that the base plate (2) has a number of impressions (5) and / or slots corresponding to the number of blades on an outer region. Impeller according to one of the preceding claims, characterized in that the suction nozzle (3) of the impeller has the shape of a cylinder, at one end of which an annular flange (15) is formed. Impeller according to one of the preceding claims, characterized in that the flange (15) of the intake connector (3) has a number of impressions (6) and / or slots corresponding to the number of blades, the impressions (6) having central elevations (17) . Impeller according to one of the preceding claims, characterized in that the flange surface (15) of the intake connector (3) is arranged at an obtuse angle with respect to the outer lateral surface. Impeller according to one of the preceding claims, characterized in that the blades (4) are connected in one piece to the rear base plate (2), an additional plate, a front cover plate and / or to the intake port (3). Method for producing an impeller consisting of several parts according to one of the preceding claims, in which the individual parts are made of sheet metal, in particular stainless steel sheet and are connected to one another by resistance welding, in particular short-term resistance welding, characterized in that in one of the working steps several interconnected blades (4) are welded to the base plate (2) and / or the intake manifold / the cover plate (3). Method for producing an impeller according to one of the preceding claims, characterized in that the blades (4) are only separated from one another after they have been welded to the base plate (2) and / or the intake manifold. Method for producing an impeller according to one of the preceding claims, characterized in that the sheet metal material for a certain number, in particular for all blade surfaces (4), is cut or punched continuously from a sheet metal surface and then shaped into the blade surfaces (4). A method for producing an impeller according to one of the preceding claims, characterized in that the base material for each part is cut and / or punched from flat sheet metal and brought into the final shape by shaping. A method of manufacturing an impeller according to one of the preceding claims, characterized in that the hub (1), base plate (2) and suction nozzle (3) are separated from the remaining sheet metal by cutting and / or punching after shaping. Method for producing an impeller according to one of the preceding claims, characterized in that after cutting / punching there are no burr-forming edges on the outside. Method for producing an impeller according to one of the preceding claims, characterized in that for shaping the hub (1) a pot shape is first formed from the flat sheet metal, in a further work step the annular projection (7) is formed on the bottom of the hub (1), in a further step, the outer wall of the hub (1) is drawn into an at least three-part fit for the axle in three sections (9) and in a further step the fit in the hub (1) is calibrated. A method of manufacturing an impeller according to any one of the preceding claims, characterized in that the fully formed hub (1) is separated from the rest of the sheet, with a flange (8) remaining on the hub (1). Method for producing an impeller according to one of the preceding claims, characterized in that for forming the base plate (2) first a central bulge (10) is formed into a basic shape of the flat sheet and in a further step in an annular region which forms the outer edge of the base plate (2), a number of impressions (5) and / or slots corresponding to the blade number are introduced. Method for producing an impeller according to one of the preceding claims, characterized in that for shaping the blade surfaces (4) first the basic shape of the blade surfaces (4) is cut out of a flat sheet, in particular punched out, in a further step, the tabs (12), which are used to fasten the intake manifold (3), are bent, in a further step the blade surfaces (4) are bent, in particular by beads, in a further step, the areas which form the outlet openings of the impeller are cut free, in particular punched out, and in a further step, the blade surfaces (4) are raised. Method for producing an impeller according to one of the preceding claims, characterized in that for shaping the intake manifold (3) a pot-shaped depression is first drawn into the sheet metal, a flange-shaped surface (15) remaining on the side of the cylindrical jacket facing away from the pot bottom, in a further step, the bottom of the pot is cut out or punched out to a collar, in a further step the collar is put through and at the same time or in chronological order the flange surface (15) is placed at an angle to the jacket and in a further step, a number of impressions (6) corresponding to the number of blades is pressed into the flange surface (15), the shape of which is formed according to the tabs (12) of the blades (4) and elevations (17) are pressed into the center thereof. Method for producing an impeller according to one of the preceding claims, characterized in that the surface of the impeller is protected, in particular by a paint, in particular a cataphoretic paint.

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