DE102017128093A1 - Impeller for use in a turbomachine - Google Patents

Abstract

The invention relates to an impeller (0) for use in a turbomachine having a plurality of blades (24). The impeller (0) is characterized by a first part (1) and by a second part (2), which are formed separately and connected to each other, wherein the blades (24) through the first part (1) and / or through the second Part (2) are formed.

Description

The invention relates to an impeller for use in a turbomachine according to the preamble of patent claim 1 and to a turbomachine with such an impeller according to claim 15.

Pumps and blowers usually each have at least one impeller, which is arranged on a shaft. The impeller can be driven in rotation and thereby a medium such. aspirate or convey a liquid or gas. In this case, the medium is detected by the blades of the impeller and pushed away in the direction of conveyance. Conversely, a flowing medium can act on the blades of an impeller and generate the rotational movement of the impeller or the shaft.

In other words, an impeller is a moving, usually rotating part of a turbomachine such. As a turbine, a centrifugal pump, a turbocompressor and the like, which either withdraws or supplies work to a flowing fluid. The counterpart to the moving impeller is the stationary stator or the tail, which directs the flow to the impeller. A stator and an impeller together form a "stage" of a turbomachine. In a multi-stage turbomachine several guide and wheels are alternately connected in series. The sum of all impellers with the connecting shaft is called rotor or rotor. Simple, freestanding wheels, especially in water turbines and drives of ships or aircraft, are also referred to as a screw or as a propeller.

An impeller usually consists of a ring of blades, which may also be referred to as blades or rotor blades. The blades are held on the shaft via a suitable attachment. Here, the adhesion must be given both for the transmission of torque to the shaft and to compensate for the centrifugal force, which can be considerable in large and fast-rotating machines. For this purpose, cohesive compounds such as e.g. One-piece casting or welding and positive connections such as Dovetail, fir-tree and the like are chosen, the latter have the advantage that they are solvable.

Since the geometries of the blades have a significant influence on the interaction between the impeller and the medium, a variety of designs are possible and necessary in order to design the blades as optimally as possible for the particular application. Currently, two-dimensional and three-dimensional blade geometries are known. The three-dimensional blade geometries usually have a constant wall thickness.

It is advantageous on the three-dimensional blade geometries that they have additional design options over only two-dimensional blade geometries. This can in particular increase the efficiency of the power transmission between impeller and medium.

The disadvantage, however, is that three-dimensional blade geometries are more complicated to produce than two-dimensional blade geometries. For example, it is possible to manufacture an impeller with a three-dimensional blade geometry in a casting process, using slides in the casting tool to achieve the three-dimensional design of the blade. However, this is relatively expensive, since the slides must be positioned in the tool before each casting process and then removed from the casting.

Alternatively, it is possible to mill an impeller with a three-dimensional blade geometry in one piece. Since this usually five-dimensional milling machines are required, which may have comparatively high acquisition and operating costs, this can lead to relatively high cost of the impeller.

Furthermore, impellers with three-dimensional blade geometries can be produced by means of additive or additive manufacturing processes. However, this type of production can lead to a comparatively high cost of the impeller.

The invention thus presents the problem of providing an impeller for use in a turbomachine of the type described above, which can be made easier and / or less expensive. This should be achieved in particular for wheels with three-dimensional blade geometries. At least an alternative to known wheels to be created.

According to the invention this problem is solved by an impeller with the features of claim 1 and by a turbomachine with the features of claim 15. Advantageous embodiments and further developments of the invention will become apparent from the following subclaims.

The present invention thus relates to an impeller for use in a turbomachine having a plurality of blades. The impeller according to the invention is characterized by a first part and by a second part, which are separated are formed and connected to each other, wherein the blades are formed by the first part and / or by the second part. In other words, the impeller is not integrally formed at least in the region of the blades, as previously known, but at least two pieces. These two parts or pieces can be made independently in this way and then joined together to at least partially form the impeller.

In this way, additional possibilities can be created to influence the shape of the impeller and in particular of the blades. In particular, blade geometries can be created which have hitherto been e.g. by casting or milling e.g. due to undercuts with a relatively high effort or not possible. This can lead to improvements in the efficiency of turbomachines. Also known blade geometries can be made easier and / or cheaper in this way. This applies in each case in particular for three-dimensional blade geometries.

In this case, the blades can be formed both exclusively by the first part or by the second part. Also, the vanes may be partially formed by the first part and partly by the second part, both parts of which may form the vanes in equal proportions or one part may have a larger fraction of the vanes than the other part. This may equally apply to all blades of the impeller or the blades may be designed differently.

The first part may preferably face the flow of the medium and the second part may be remote from the flow of the medium.

According to one aspect of the present patent application, the first part has a plurality of support areas for receiving a respective blade and the second part has a plurality of blade areas which form the blades. As a result, the first part can serve, so to speak, as a carrier part of the impeller, which faces the flow of the medium and thus can substantially absorb the forces of the inflowing medium. The second part may be formed as a blade part and form the blades at least substantially to exclusively, so that the exchange of work between blades and medium can take place at least substantially over the second part. Both parts can thus be designed optimized for their respective task.

According to a further aspect of the present invention, intermediate spaces are formed between the carrier regions and between the blade regions, in each case in the circumferential direction, through which a medium can flow. As a result, the flow of the medium can be ensured by the impeller according to the invention. This flow may preferably take place substantially along the longitudinal axis of the impeller.

According to a further aspect of the present invention, the first part has at least one connecting element, preferably at least one connecting element per carrier region, and the second part at least one connecting element, preferably at least one connecting element per blade region, wherein the first part and the second part by means of the connecting elements are positively connected with each other. In this way, a simple but effective connection between the two parts can be created, which can also be solved non-destructively. The connecting elements can simultaneously serve as positioning and / or orientation aid in the assembly of the two parts.

To form the positive connection between the respective connecting elements, all possible connections suitable for this, such as, for example, Tongue and groove, dovetail and the like can be used.

A positive connection between a carrier region and the corresponding blade region can be sufficient. However, it is also possible to provide a plurality of identical or differently acting positive connections per carrier region and blade region in order to improve the grip.

According to a further aspect of the present invention, the connecting region of the first part as a projection and the connecting region of the second part is formed as a recess, or vice versa. This allows a positive connection can be achieved easily and safely. The division, which part of the projection and which part has the indentation, can be made depending on the application.

According to a further aspect of the present invention, the impeller further comprises a third part, which is formed separately and connected at least to the second part. As a result, the impeller can be divided into even more items in order to use the previously described properties and advantages more diverse.

The third part does not necessarily have to be part of the impeller, the geometry can also be formed in the turbomachine itself. With others Words, the impeller cover may alternatively be part of the turbomachine.

According to another aspect of the present invention, the third part has at least one recess through which a medium can flow. In this way, the flow of the medium can be ensured by the impeller according to the invention in the case of the existing third part.

According to a further aspect of the present invention, at least one blade, preferably all blades, has a blade edge which faces the third part, and the third part has at least one blade receptacle, preferably a plurality of blade receptacles, which receives the blade edge of a blade , Thereby, the blade or the blades can be held from the side of the third part to give them more stability.

According to a further aspect of the present invention, the blade receptacle holds the blade edge in a form-fitting manner. As a result, a simple but secure hold of the blade edge can be achieved by the third part.

According to a further aspect of the present invention, the blade receptacle is formed as a groove. As a result, a positive connection can be achieved in a simple manner.

A groove is merely a possibility of joining, alternatively, e.g. be added on impact or it can be joined via pins to holes.

According to a further aspect of the present invention, the first part and / or the second part and / or the third part is or are each formed in one piece. This can e.g. by casting metal or plastic, which can be a very low cost manufacturing process, especially for high volumes.

According to a further aspect of the present invention, at least one blade, preferably all blades, are formed at least in sections three-dimensionally. In this way, an impeller can be created, which can contribute to the highest possible efficiency of a turbomachine.

According to a further aspect of the present invention, at least one blade, preferably all blades, has different wall thicknesses in sections. In this way, the blades can be formed with a lower weight, which can benefit the efficiency of the turbomachine. This can be favored or made possible precisely by the multi-piece design of the impeller.

According to a further aspect of the present invention, at least one blade, preferably all blades, facing away from the first part, is tapered, preferably tapering in the form of a wedge. This can lead to blades which are facing the medium sufficiently thick-walled to provide the required stability, but at the same time have a reduced weight.

Embodiments with sections of different wall thickness or wedge-shaped tapered blades are preferred embodiments of the invention. However, even with constant wall thicknesses without rejuvenation, the invention avoids the use of gate valves and is therefore also advantageous.

The present invention also relates to a turbomachine with an impeller as described above. As a result, the properties and advantages described above can be used in a turbomachine.

• 1 eine schematische Explosionszeichnung eines erfindungsgemäßen Laufrads gemäß einem ersten Ausführungsbeispiel;
• 2 eine schematische Explosionszeichnung eines erfindungsgemäßen Laufrads gemäß einem zweiten Ausführungsbeispiel;
• 3 eine seitliche Darstellung eines erfindungsgemäßen Laufrads;
• 4 eine Schnittdarstellung der 3; und
• 5 eine perspektivische Darstellung eines erfindungsgemäßen Laufrads.

Two embodiments of the invention are shown purely schematically in the drawings and will be described in more detail below. It shows

• 1 a schematic exploded view of an impeller according to the invention according to a first embodiment;
• 2 a schematic exploded view of an impeller according to the invention according to a second embodiment;
• 3 a side view of an impeller according to the invention;
• 4 a sectional view of 3 ; and
• 5 a perspective view of an impeller according to the invention.

The above figures are considered in cylindrical coordinates. It extends a longitudinal axis X in height. Perpendicular to the longitudinal axis X extends a radial direction R , Around the longitudinal axis X around a circumferential direction (not shown) extends.

The 1 and 2 show two different embodiments of an impeller according to the invention 0 , The impeller 0 consists of three parts 1 . 2 . 3 ,

From bottom to top along the longitudinal axis X Considered the impeller 0 at the bottom the first part 1 on which also as a carrier part 1 can be designated. The first part 1 has a one-piece body 10 with a middle range 11 which is immediately about the longitudinal axis X is formed around. The middle area 11 has a recess 13 in the form of a wave recording 13 on, which is along the longitudinal axis X extends and receiving a shaft of a turbomachine is used (not shown). From the middle area 11 extend radially a plurality of carrier areas 14 as shovel shots 14 path. The carrier areas 14 form between them in the circumferential direction spaces 4 through which a medium can flow. At their radially outer ends run the carrier areas 14 in a common outer area 12 together, which is formed annularly closed in the circumferential direction and the first part 1 concludes.

Along the longitudinal axis X further up the second part follows 2 , which also as a blade part 2 can be designated. Also the second part 2 has a one-piece body 20 on which in turn a recess 23 along the longitudinal axis X as a wave recording 23 of the second part 2 which has an inner area 21 of the second part 2 is formed. From the inner area 21 several blade areas extend 24 radially outward to there in a common outer area 22 of the second part 2 proceed. The blade areas 24 which the blades 24 form substantially and therefore can be equated with these, also have gaps in the circumferential direction 4 on. The first part 1 facing away from the blades 24 one blade edge each 26 on, with the shovels 24 close at the top. The shovels 24 in each case run to the blade edge 26 wedge-shaped tapering.

According to the invention, the first part 1 and the second part 2 each integrally formed eg as a metal casting or as an injection molded plastic part and are then assembled. For this example, the second part 2 with the lower edges or surfaces of the blades 24 along the longitudinal axis X from the top to the first part 1 placed. The two inner areas 11 . 21 are matched to one another in such a way that the two wave shots 13 . 23 lie directly on top of each other and together the longitudinal axis X correspond. Also, the two outer areas 12 . 22 coordinated so that they can rest on each other. Likewise, the carrier areas 14 and the blade areas 24 coordinated that the spaces between 4 correspond to each other as well as that the carrier areas 14 and the blade areas 24 Corresponding to each other, the three-dimensional geometry of the blades 24 form. This can be achieved according to the invention more diverse and / or cheaper than previously known.

According to the first embodiment of the 1 become the two parts 1 . 2 as previously described set to each other. According to the second embodiment of the 2 have the carrier areas 14 of the first part 1 each a connecting element 15 in the form of a projection 15 on. The blade areas 24 of the second part 2 each have a connecting element 25 in the form of a corresponding indentation 25 on. Through the interaction of the two connecting elements 15 . 25 can be an additional positive fit between the two parts 1 . 2 be created.

The impeller according to the invention 0 closes along the longitudinal axis X upwards with a third part 3 which also serves as cover 3 of the impeller 0 can be designated. Also the third part 3 is by a one-piece body 30 formed, which is designed annularly curved and along the longitudinal axis X a recess 33 in the form of an opening 33 through which the medium can flow. The outer surface of the curvature of the one-piece body 30 forms an outside 32 and the opposite inner surface an inside 31 of the third part 3 , On the inside 31 run several shovel shots 34 in the form of grooves 34 spirally. In the assembled state of the impeller according to the invention 0 become the upper blade edges 26 in the grooves 34 recorded and held, see eg 4 ,

The impeller according to the invention 0 can be arranged in this form on a shaft of a turbomachine, so that, for example, by the active operation of the shaft, a medium such as air from the side of the first part 1 sucked in and through the gaps 4 of the first part 1 and the second part 2 can be passed to the impeller 0 over the opening 33 of the third part 3 to leave again. By the geometry of the blades 24 This can be done comparatively effective as previously described.

LIST OF REFERENCE NUMBERS

A

section axis

R

radial direction

X

longitudinal axis

0

Wheel

1

first part; support part

10

one-piece body of the first part 1

11

inner area of the first part 1

12

outer area of the first part 1

13

Recess of the first part 1 ; Shaft recording of the first part 1

14

Support areas; scoop shots

15

Connecting element of the first part 1 ; head Start

2

second part; blade part

20

one-piece body of the second part 2

21

inner area of the second part 2

22

outer area of the second part 2

23

Recess of the second part 2 ; Wave recording of the second part 2

24

Blade regions; shovel

25

Connecting element of the second part 2 ; indentation

26

(upper) blade edges

3

third part; cover

30

one-piece body of the third part 3

31

inside

32

outside

33

Recess of the third part 3 ; opening

34

Scoop shots; groove

4

interspaces

Claims (15)

Impeller (0) for use in a turbomachine, comprising a plurality of blades (24), characterized by a first part (1) and by a second part (2), which are formed separately and connected to each other, wherein the blades (24) be formed by the first part (1) and / or by the second part (2). Impeller (0) to Claim 1 , characterized in that the first part (1) has a plurality of support areas (14) for receiving a respective blade (24), and that the second part (2) has a plurality of blade areas (24) which surround the blades (24 ) train. Impeller (0) to Claim 2 , characterized in that between the carrier regions (14) and between the blade regions (24) in each case in the circumferential direction intermediate spaces (4) are formed, through which a medium can flow. Impeller (0) according to one of the preceding claims, characterized in that the first part (1) at least one connecting element (15), preferably at least one connecting element (15) per carrier region (14), and the second part (2) at least one connecting element (25), preferably at least one connecting element (25) per blade area (24), wherein the first part (1) and the second part (2) by means of the connecting elements (15, 25) are positively connected to each other. Impeller (0) to Claim 4 , characterized in that the connecting region (15) of the first part (1) as a projection (15) and the connecting region (25) of the second part (2) is formed as a recess (25), or vice versa. Impeller (0) according to one of the preceding claims, characterized by a third part (3) which is formed separately and connected at least to the second part (2). Impeller (0) to Claim 6 , characterized in that the third part (3) has at least one recess (33) through which a medium can flow. Impeller (0) to Claim 6 or 7 , characterized in that at least one blade (24), preferably all blades (24), a blade edge (26) which faces the third part (3), and that the third part (3) at least one blade receptacle (34) , Preferably, a plurality of blade receptacles (34), which receives the blade edge (26) of a blade (24). Impeller (0) to Claim 8 , characterized in that the blade receptacle (34) holds the blade edge (26) in a form-fitting manner. Impeller (0) to Claim 9 , characterized in that the blade receptacle (34) is formed as a groove (34). Impeller (0) according to any one of the preceding claims, characterized in that the first part (1) and / or the second part (2) and / or the third part (3) is in each case integrally formed / are. Impeller (0) according to one of the preceding claims, characterized in that at least one blade (24), preferably all blades (24), at least partially formed three-dimensionally. Impeller (0) according to any one of the preceding claims, characterized in that at least one blade (24), preferably all blades (24), partially different wall thicknesses. Impeller (0) to Claim 13 , characterized in that at least one blade (24), preferably all blades (24), the first part (1) facing away from tapering, preferably tapered wedge-shaped, is formed. Turbomachine with an impeller (0) according to one of the preceding claims.

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