EP2386765A1 - Flow guidance device - Google Patents

Abstract

The flow-guiding device comprises a shovel which is guided as a profile part having a central part (2). The profile part is section of a strand profile which comprises a support area (6) and a shovel area (4). An angle is formed between the support area and the shovel area. The angle is provided between zero degree and seventy five degree, particularly between zero degree and forty five degree. The strand profile is manufactured from plastic material or metal or plastic metal mixture. Independent claims are also included for the following: (1) a method for manufacturing a flow-guiding device; and (2) a radial pump with a radial pump propeller.

Description

The invention relates to a flow-guiding device of a turbomachine, wherein the device comprises a blades having, executed as a profile part central part.

Such a flow-guiding device is known from DE 10 2007 027 370 A1 as a bent from a single sheet metal wheel known. For mounting on a shaft, a material area located between the blades is bent towards the rear side thereof. A disadvantage of this design, however, is that the attachment of the blades on the shaft is very unstable.

The GB 1 140 334 A describes an impeller in which the impeller blades are formed by forming a sheet metal disc. Between the blade surfaces of the sheet metal disc connecting means are formed, which in turn are secured to form covered blade channels two cover plates. Such an impeller requires a high material usage.

The invention has the object of providing a flow-leading device for energy transfer, comprising a blades having central part of a turbomachine to further develop, the assembly is greatly simplified and the use of materials should be reduced. Furthermore, the object is to develop a method for producing a central part according to the invention.

The solution to this problem provides for the flow-guiding device, that the profile part is formed as a section of an extruded profile. Depending on an operating requirement, an accordingly long section is separated from an extruded profile, which constitutes the functionally essential central part for the production of said flow-guiding device. From an arbitrarily long extruded profile, numerous sections can be produced, which are processed for example to wheels of the same or different width.

In the profile, a distinction is made between a support region and at least one blade region, the blade regions being arranged so as to protrude radially away from the support region. Depending on the given profile, the blade regions form the later blades of a cut profile part in a hydraulically advantageous form. The connection area between the support area and the blade area is referred to as foot point.

The arrangement of the blades is particularly advantageous if a positive or negative angle β between 0 ° and 75 °, in particular between 0 ° and 45, is formed between a radial ray of the support region passing through the base of the blade and a tangent of the center line of the blade region °. Angle specifications in this area lead to advantageous hydraulic properties in a turbomachine.

An improvement in the hydraulic properties of the turbomachine can be achieved if the blade region has a curved shape in whole or in part. This improves the energy transfer in the turbomachine.

In a further embodiment, the extruded profile is produced by extrusion, forming or machining. The extruded profile can be plastically formed as an extruded part or machined from an elongated semi-finished or by forming. When extruding, for example, there is the advantage that the positions of the blades by a shaping die permanently and very are precisely defined. Especially with multiple blades whose shape and arrangement can be precisely determined by the extrusion. The advantage here is that the semi-finished for producing the flow-guiding device, namely the extruded profile, depending on the material and the geometry of the profile can be produced in the most advantageous manner.

To improve the hydraulic properties, it is advantageous if the blades are at a certain angle to the flow direction of the medium on the profile part. So that the blade areas of a profile part already have the necessary angle of attack in the axial direction, in another embodiment the extruded profile is made helically during production. When using a coiled extruded profile post-processing of the cut profile part is no longer or only to a small extent necessary.

The choice of the torsion angle α, with which the extruded profile is coiled, is highly dependent on the later application. In the simplest case, one will provide a fixed torsion angle α for the entire extruded profile of any length. The individual sections then have a uniform blade position, regardless of the length of the section.

A further improvement of the hydraulic properties can be achieved by already executing the spiraling with variable torsion angle α in the production of the extruded profile. For the length of the individual sections of the extruded profile a permanent pattern is repeatedly stamped. If the predefined sections are separated from the extruded profile, geometrically similar blades with the advantageous geometry are obtained.

The torsion angle should be in the range between 0 ° and 75 ° for the extruded profiles, in particular between 25 ° and 45 °, so the angles of attack of the blades can be optimally adapted to the hydraulic requirements.

To further improve the hydraulic properties of the individual blades in the production of the strand profile, for example, by choosing a corresponding extrusion die, given a tortuous shape. Likewise, this can be given to the individual components by forming. The forming process is adapted to the material used. For the extruded profile also blade shapes are feasible, in which the blades at the base are wider or narrower.

In a further embodiment, the support area has connection areas to other components of the turbomachine. The advantage here is that a torque transmission can be done by means of common connection techniques.

In a further embodiment, the connection region of the support region is designed as a hub. The hub can be imaged in an advantageous manner, including the introduction of an anti-rotation device of any kind, such as feather key grooves or teeth, already by the extrusion die. A subsequent processing of the section, for example, the drilling of the hub, is eliminated. The component according to the invention can be joined directly to a shaft without further post-processing, whereby a simple and cost-effective production and assembly is possible.

As an alternative to this, a shaft or a shaft journal can be formed as a connection region in the support region of the profile part. For this purpose, a profile is produced during extrusion, the holding area is formed as a cylindrical core. The selected length of a section includes the area with the blades and the adjacent area of the shaft. With a processing step, the blade areas are removed in the area of the shaft, for example by turning off, cutting, bending or the like. The advantage here is that the resulting component of shaft and blades is integrally formed, whereby its stability is increased.

Likewise, it is advantageous to choose the length of the shaft so that between the drive and the impeller, a sealing device, in particular a mechanical seal, can be arranged. The advantage here is that on the one-piece component already the necessary space for the seal is provided.

In a further advantageous embodiment, the extruded profile is made of plastics, or highly, with different materials, filled plastics. The advantage here is that these are processed by default in extruders and high surface qualities and dimensional accuracy can be achieved. The extruded profile can also be produced from metallic wrought alloys. These are also suitable for processing in the extruder and allow various forms of finishing.

In addition, the highly filled plastics can also be converted by treatments, such as an outgassing or sintering process, into a ceramic, vitreous or metallic material or composite material. Further treatment, such as infiltration of the converted material to improve material properties, may also be desirable.

In a further embodiment, at least one flow-guiding boundary element is arranged on the profile part. The advantage here is that the flow guidance is improved by such a limiting element.

In a further advantageous embodiment, the limiting element is wholly or partially formed as a ring-shaped or disc-shaped component. These designed as a support or cover plate limiting elements increase the efficiency of a centrifugal pump or turbine runner.

It is particularly advantageous if the treatments for material adjustment are connected to the connection to the boundary element or elements such as deck and / or support plate, for example by soldering or sintering processes.

The invention further describes a method for producing a flow-guiding device with the properties shown. In the method, in a first step, a rod-shaped extruded profile with a Supporting area and provided at least one radially projecting blade area. From this extruded profile, a section is separated perpendicular to the longitudinal axis as a profile part in the shape of the extruded profile and on the support area a fastening device is formed. The advantage here is that a flow-guiding device, such as an impeller for a centrifugal pump can be produced by a few processing steps from a semi-finished product.

In a variant of the method, the profile part is brought to a next step by post-processing in a hydraulically advantageous form. This can be done by machining or reshaping post-processing, the at least one blade area and / or the composite point of the blade area with the holding area. This step can be carried out at a particularly favorable choice of parameters already at the separation of the profile.

In a further variant of the method, the extruded profile is coiled with a fixed and / or variable torsion angle α. This has the advantage that special geometries are made possible, which significantly improve the hydraulic properties of the flow-guiding device.

In a further step, the extrusion can be connected to a support disc and / or a cover plate, whereby both open and closed wheels are produced. Finally, a mounting option can be performed on the holding area of the profile part.

This method has the advantage that the production of a flow-guiding device, in particular an impeller for a centrifugal pump, is greatly simplified. Likewise, wheels of any width can be produced without significant design effort.

For flow-conducting devices, which are made of ceramic or hard metal materials, provides an advantageous embodiment of the According to the invention, the extruded profile is designed as a green body, that a section is taken from the extruded profile, that this section is provided, as required, with support and / or cover plate, which are likewise designed as green bodies, and finally the composite green body is sintered , The advantage here is that the flow-guiding device is integrally sintered executable.

The flow-guiding device according to the invention is particularly suitable for use in a centrifugal pump, wherein the centrifugal pump is designed at least one stage and at least one inlet. The advantage here is that the centrifugal pump impeller is easy and inexpensive to produce.

Further embodiments result from the combination of the previously shown and are therefore not further elaborated here.

Figur 1a-b

ein offenes Laufrad mit einer Deckscheibe, die

Figur 2a

ein Strangprofil, die

Figur 2b

einen Abschnitt von dem Strangprofil von Figur 2a, die

Figur 3a

ein Strangprofil mit Torsionswinkel α=0°, die

Figur 3b

ein Strangprofil mit Torsionswinkel α≠0°, die

Figur 4

ein Strangprofil mit äußerem Tragbereich, die

Figur 5

verschiedene Ausführungsformen des Torsionswinkels, die

Figur 6a-d

verschiedene Ausführungen der erfindungsgemäßen Einrichtung und die

Figur 7

eine Kreiselpumpe mit der erfindungsgemäßen Einrichtung.

Embodiments of the invention are illustrated in the drawings and will be described in more detail below. It show the

FIG. 1a-b

an open wheel with a cover disc, the

FIG. 2a

an extruded profile, the

FIG. 2b

a section of the extruded profile of FIG. 2a , the

FIG. 3a

an extruded profile with torsion angle α = 0 °, the

FIG. 3b

an extruded profile with torsion angle α ≠ 0 °, the

FIG. 4

an extruded profile with outer support area, the

FIG. 5

various embodiments of the torsion angle, the

Figure 6a-d

various embodiments of the device according to the invention and the

FIG. 7

a centrifugal pump with the device according to the invention.

The FIG. 1 shows an impeller 1, as used in a centrifugal pump, in the open design. In this case, an inventive central part 2 is equipped with a support disk 3. Shown in FIG. 1 a the supervision and in FIG. 1b an isometric view of the impeller 1 with here eight blades. The shovels are formed of blade portions 4, whose shape is adapted to the hydraulic stress. In the example shown, the blades have an arcuate course 5. About a support portion 6, the blade portions 4 are integrally connected. A hub 7 comprises a central hole 8 for receiving a shaft, in particular a drive shaft. Both the blade portions 4 and the hub 7 are fixedly connected to the support disk 3. Depending on the material, the connection can be made by joining, soldering, gluing, welding or otherwise.

The FIG. 2 a shows an extruded profile 9 as required for the production of the in FIG. 1 shown impeller 1 was used. The extruded profile 9 has the shape of the blade areas 4, which have a curved course 5. An angle β describes the position of the blade regions 4 projecting radially from the support region 6. The support region 6 simultaneously forms the hub 7. The extruded profile 9 is straight. A torsion of the extruded profile 9 was not made, which is why a torsion angle α in this case is 0 °. A length L defines the total length of the profile.

The FIG. 2 b shows a profile part 10 as a section of the in Figure 2 a The extruded profile 10 has a length I, where I <L. The blade areas 4 are clearly in the form of blades and the support area 6 is designed as a hub 7 for receiving a shaft. This profile part 10 can be used in this form as an impeller 1 in star form for a centrifugal pump.

The FIG. 3 A shows in side and side view, the example of a simple achtschaufeligen profile, the design of an extruded profile 9 without central hole with a torsion angle α equal to 0 °. Shown are the eight blade areas 4 and the solid support area 6. From the length L of the entire profile, a profile part 10 with the length I can be separated.

On the other hand shows FIG. 3 b an extruded profile with likewise eight blade areas 4, wherein here in the support area 6, a hub 7 is formed. The illustration of the side view shows that this extruded profile is coiled, ie designed as a helical profile 11, wherein the torsion angle α is greater than 0 °. From this helical profile 11 profile parts 10 can be separated with the length I, the blade portions 4 have a hydraulically advantageous shape.

In FIG. 4 an alternative form of the extruded profile 9 is shown with an outer support portion 6 and outgoing inner blade portions 4. The connection area between the support area and the blade area is referred to as foot point. The arrangement of the blades is particularly advantageous if a positive or negative angle β between 0 ° and 75 ° is formed between a radial jet of the support region passing through the root of the blade and a tangent of the center line of the blade region at the root. The choice of the angle β depends on the hydraulic requirements.

In FIG. 5 Different configurations of the torsion angle α are shown as a function of the length L of the extruded profile. The torsion angle α can assume a constant value not equal to 0 ° after the dot-dashed curve 14 or 0 ° in accordance with the dashed curve 15. Also possible is any length-dependent function of the torsion angle α, as shown in the solid curve 17. Starting from the zero point up to a dividing line 16 of the extruded profile 9, a profiled part 10 with a periodically repeating torsion angle α = is variably separable with a length I. Hereby, the same torsion sequence is possible for each following profile part 10, the length L of the extruded profile 9 corresponding to an integer multiple period of the length I of a section, that is to say of a profiled part 10. With a subsequent processing so particularly streamlined blade shapes for such a kind created impeller 1 can be generated.

The torsion angle α can be chosen so that right-handed or left-handed wheels are possible for later use.

The FIG. 6 shows the various types of wheels 1, which can be made of a profile part 10, which is the portion of a strand profile 9 or helical profile 11 described above.

The FIG. 6 a shows a section of the extruded profile 9, which has already been finished. The shape of the blade sections 4 has been adapted to the hydraulic requirements as well as to a casing housing the impeller. The support portion 6 is designed with a hub 7 and a hole 8 for receiving a shaft. A star-shaped impeller 1 without support and cover plate can be made in the simplest way.

The FIG. 6 b shows the impeller 1 of Figure 6 a in which a pressure-side support plate 3 has been added. The geometric shape of the support disk 3 depends on the application of the impeller 1 and is also based on the spatial requirements in the pump housing. Such an impeller shape is also known as an open impeller.

The Figure 6 c shows a so-called closed impeller 1, in addition to the structure of the FIG. 6 b still a suction-side cover plate 18 has been attached. The geometric shape of this cover plate 18 depends on the machined portion of the extruded profile 9, the profile part 10 and the application of the impeller 1 and also based on the spatial requirements in the pump housing.

The FIG. 6 d shows a further variant of the impeller 1, in which a shaft 19 is provided for attachment. The shaft 19 is designed so long that it is possible to attach a seal, preferably a mechanical seal. In this variant, no torque transfer takes place in the fluid-contacted space.

The FIG. 7 shows a centrifugal pump 20 with a plurality of blades having impeller 1, a support plate 3 and a cover plate 18. According to the embodiment according to FIG. 6 d a shaft 19 is formed with a seal 21, which is designed here as a mechanical seal and a pump housing 22 of the centrifugal pump 20 seals. On the shaft 19, a torque 24 will be transmitted from outside a fluid space 23.

Details, such as are necessary for the operation of a device according to the invention, for example in a centrifugal pump 20, can be easily incorporated. Thus, it is possible to provide conventional devices of centrifugal pumps, as shown here by way of example as gap region 25, advantageously on the impeller 1.

LIST OF REFERENCE NUMBERS

α

torsion

β

angle

L

Length of the profile

I

Length of the section

1

Wheel

2

central part

3

carrying disc

4

blade area

5

Arc-shaped course

6

support area

7

hub

8th

hole

9

extruded profile

10

profile part

11

helical profile

12

tangent

13

center line

14

Curve α is equal to 0 °

15

Curve α constant not equal to 0 °

16

parting plane

17

free curve α (L)

18

cover disc

19

wave

20

rotary pump

21

poetry

22

pump housing

23

fluid space

24

torque

25

gap region

Claims (22)

Flow-guiding device of a turbomachine, wherein the device comprises a blades having, designed as a profile part (10), central part (2),
characterized in that
the profile part (10) is a section of an extruded profile (9). Flow-guiding device according to claim 1, characterized in that the extruded profile (9) has a support region (6) and at least one blade region (4) which is connected in a radially projecting arrangement with the support region (6). Flow-guiding device according to claim 2, characterized in that between the support region (6) and the blade region (4) an angle (β) between 0 ° and 75 ° is formed, in particular between 0 ° and 45 °. Flow-guiding device according to one of claims 1 to 3, characterized in that the blade region (4) has wholly or partially an arcuate course (5). Flow-guiding device according to one of claims 1 to 4, characterized in that the extruded profile (9) is produced by extrusion, forming or machining. Flow-guiding device according to one of claims 1 to 5, characterized in that the extruded profile (9) is a helical profile (11). Flow-guiding device according to claim 6, characterized in that the helical profile (11) has a fixed and / or variable torsion angle (α). Flow-conducting device according to claim 6, characterized in that the torsion angle (α) in the range between 0 ° and 75 °, in particular between 25 ° and 45 °. Flow-guiding device according to one of the preceding claims, characterized in that the support region (6) has connecting regions to other components of the turbomachine. Flow-conducting device according to one of claims 1 to 9, characterized in that the support region (6) as a hub (7) is formed. Flow-conducting device according to one of claims 1 to 9, characterized in that the support region (6) as a shaft (19) or shaft journal is formed. Flow-conducting device according to claim 11, characterized in that a seal (21), in particular a mechanical seal, is arranged on the support region (6). Flow-conducting device according to one of the preceding claims, characterized in that the extruded profile (9) is made of plastic, highly filled plastic, plastic-metal mixture or metal. Flow guiding device according to one of the preceding claims, characterized in that the highly filled plastics by a Outgassing or sintering process are converted into a ceramic, glassy or metallic material or composite material. Flow-conducting device according to one of the preceding claims, characterized in that on the profile part (10) at least one flow-guiding limiting element, in particular support (3) and / or cover plate (18) is arranged. Flow-guiding device according to claim 14, characterized in that the limiting element is wholly or partly formed as a ring-shaped or disc-shaped component. A method for producing a flow-guiding device, characterized in that a rod-shaped extruded profile (9) having a support region (6) and at least one radially projecting blade region (4) is provided that perpendicular to the longitudinal axis of the extruded profile (9) a section as a profile part ( 10) in the form of the extruded profile (9) is separated and that on the support portion (6) a fastening device is formed. A method according to claim 17, characterized in that on the profile part (10) by post-processing of the flow-guiding blade region (4) is formed a hydraulically advantageous shape. Method for producing a flow-guiding device according to claim 17 or 18, characterized in that the extruded profile (9) is wound in the manufacture with a fixed and / or variable torsion angle (α), Method for producing a flow-guiding device according to one of claims 17 to 18, characterized in that the profile part (10) with a support disc (3) and / or a cover plate (18) is provided. Method for producing a flow-guiding device according to one of the preceding claims, characterized in that the extruded profile (9) is designed as a green body that from the extruded profile (9) a profile part (10) is removed, that this profile part (10), if necessary, with support - (3) and / or cover plate (18), which are also designed as a green body, is provided and that finally the composite green body is sintered Centrifugal pump (20), wherein the centrifugal pump (20) is at least one stage and at least one inflow, characterized in that the centrifugal pump (20) with a flow-guiding device, in particular a centrifugal pump impeller (1), according to one of claims 1 to 15 equipped.

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