EP3532729B2 - Horizontally split screw-spindle pump - Google Patents

Description

The invention relates to a screw pump or screw spindle pump, in particular a single- or multi-flow double-screw pump or double-screw spindle pump, comprising a multi-part housing and at least two coupled, chamber-forming rotors, each with at least one thread-shaped profile formed at least in some areas with screw-shaped channels and with partition walls delimiting the channels, wherein the rotors rotate in opposite directions and the partition walls mesh with one another like gears, a rotor housing part, wherein the rotor housing part encloses the rotors without contact, wherein the rotors form at least one delivery chamber with the rotor housing part for the fluid to be delivered, wherein the delivery chamber moves axially along the rotor axes and delivers the fluid from a suction chamber into a pressure chamber, a suction-side connection element fluidically connected to the suction chamber and a pressure-side connection element fluidically connected to the pressure chamber.

Such screw pumps are from the DE 716 161 A , DE 197 49 572 A1 , EN 20 01 000 A , EN 20 01 015 A , GB645817A and US 5 601 414 A known. Such a pump is suitable for pumping fluids such as liquid plastic or other chemical products. The disadvantage of the previously known pump, however, is the high manufacturing and maintenance costs. In particular, the storage of the rotors in the removable side wall of the pump housing means that the rotors have to be adjusted in a complex way after the pump has been dismantled for cleaning and maintenance. Manufacturing from cast steel is difficult due to the complicated shape and the double wall in some sections between the spindle bore and the pump housing.

The EP 2 606 234 A2 relates to a rotary piston pump for conveying a fluid medium containing solids, comprising an inlet opening and an outlet opening for the medium to be conveyed, two rotary pistons arranged in a pump housing with intermeshing rotary piston vanes, wherein each of the two rotary pistons is torque-proof attached to a respective shaft and can be driven by the respective shaft, and wherein the two shafts are coupled to one another by a gear arranged in a gear housing, wherein the inlet opening and the outlet opening are arranged on a connection housing.

The invention therefore addresses the problem of providing a screw pump that allows simple manufacture and maintenance.

According to the invention, this problem is solved by a screw pump having the features of patent claim 1.

According to the invention, the screw pump is characterized in that the suction-side connection element and the pressure-side connection element are arranged on a connection housing part of the multi-part housing, wherein the housing has a largely flat parting plane running parallel to the rotor axes between the rotor housing part and the connection housing part.

This makes production and maintenance much easier. In addition, a modular design of the pump can be achieved by combining different running housing parts and different connection housing parts. In addition, the housing parts have almost no undercuts and no double walls, which makes manufacturing the parts using the casting process much easier. This means that not only casting but also special materials can be processed well. The flat parting plane also offers simple and long-lasting sealing options between the housing parts of the pump housing. The arrangement of the suction-side and pressure-side connection elements in a common connection housing part, which can be easily separated from the running housing part by the parting plane, also enables the connection housing part to remain in the pipe assembly during maintenance work. This means that the suction-side and pressure-side connection elements can remain connected to the pipes during maintenance work.

Multi-flow screw pumps are pumps in which two or more pairs of screws are arranged in the impeller housing, which then work in parallel between a common pressure chamber and a common suction chamber.

According to an advantageous embodiment of the invention, the parting plane runs through the suction chamber and the pressure chamber. Such a course of the parting plane offers advantages in terms of modularity and maintenance. In addition, such a course of the parting plane has further advantages in production, since hardly any undercuts are required. The parting plane does not run within the spindle axes, so that these are not directly exposed when the barrel housing part and the connection housing part are dismantled.

An advantageous design is that the rotors are mounted in the barrel housing part. The centering of the bearing or the bearing itself are contained in the barrel housing part. The bearing of the rotors in the barrel housing part makes assembly easier during production and also reduces the effort required to maintain the pump. In order to store the rotors in the barrel housing part, this also has the centering for the bearing of the rotors. In addition, the position of the rotors in the barrel housing part can be checked before connecting to the connection housing part due to the better accessibility. This makes it easy to ensure that the barrel housing part encloses the rotors without contact and that the rotors form at least one sealed delivery chamber with the barrel housing part.

According to an advantageous embodiment of the According to the invention, the barrel housing part is designed as a single piece. The single piece design of the barrel housing part offers particular advantages in the alignment and mounting of the rotors in the barrel housing part. The single piece design of the barrel housing part, in particular together with the mounting of the rotors in the barrel housing part, offers the advantage that no additional tolerances need to be taken into account during assembly when positioning the rotors. Such additional tolerances usually arise because the housing part which forms the feed chamber with the rotors is different from the component which mounts the rotors.

A particularly advantageous development is that the connection housing part is designed as a single piece. A single-piece design of the connection housing part makes it easier to assemble it with the other housing parts of the pump and the pipe system connected to the pump. The manufacture of the connection housing part is also made significantly easier by the single-piece design.

A preferred embodiment provides that the connection housing part together with the barrel housing part forms the suction chamber and the pressure chamber. The formation of the suction chamber and the pressure chamber by the connection housing part and the barrel housing part offers easy accessibility to the spaces formed by the housing parts when dismantling the barrel housing part from the connection housing part.

A particularly advantageous development is that the connection housing part has a partition between the suction chamber and the pressure chamber. This partition can be designed differently depending on the requirements at the location where the pump is used, for example to adapt the pump's delivery direction. If a so-called "in line" configuration of the connection elements is required, the partition between the suction chamber and the pressure chamber can be designed differently than with other desired configurations of the connection housing part, in which the connection elements are offset from one another or arranged at an angle. The separation of the running housing part and the connection housing part also creates flexible adaptation options for the pump thanks to the modularity gained.

Another advantageous design is that a pressure compensation element is arranged in the partition wall. The pressure compensation element between the pressure chamber and the suction chamber prevents damage to the pump if, for example, the pipe system connected to the pressure chamber is blocked. In this case, the pressure compensation element designed as an overload valve would divert the excess pressure generated in the pressure chamber towards the suction chamber and thus prevent damage to the pump and the pipe system. The arrangement of a pressure compensation element in the partition wall is particularly advantageous, as this can be done with little assembly effort and the construction is not prone to errors.

An advantageous embodiment of the invention provides several division planes parallel to the rotor axes. On these additional division planes, which offer the same access to the suction and pressure chamber of the pump as the first division plane to the connection housing, further additional functions such as pressure protection, flushing connections, bypass devices, etc. can be provided.

An advantageous embodiment of the invention provides that a flat seal is arranged between the running housing part and the connection housing part. The flat design of the dividing plane between the running housing part and the connection housing part enables the use of a flat seal between the housing parts of the pump. A particular advantage here is that flat seals are relatively easy to install and are durable and not susceptible to faults. The flat seals offer enormous advantages, particularly with regard to media and temperature resistance.

An alternative embodiment of the invention provides that an O-ring seal is arranged between the barrel housing part and the connection housing part.

According to the invention, at least one support foot is provided on the connection housing part. The arrangement of a support foot on the connection housing part enables the connection housing part to support itself from the ground. This is particularly advantageous when the barrel housing part is dismantled for maintenance and the connection housing part remains in the connected pipe assembly. This means that the connection housing part does not place any strain on the pipe assembly during maintenance work. This also makes central suspension possible. This also allows the barrel housing part to be mechanically decoupled.

A preferred embodiment provides that the rotors can be driven by a drive arranged in a drive housing part of the multi-part housing. The arrangement of the drive in a drive housing part increases the modularity of the pump housing parts. In this way, different rotor housing parts and connection housing parts can be combined with different drives in order to be able to optimally adapt the screw pump to the requirements of the intended use and location. The drive can be connected directly via a shaft leading out of the housing.

According to an advantageous embodiment of the invention, the drive comprises a magnetic coupling. By incorporating a magnetic coupling into the drive of the screw pump, a mechanical separation between the conveying medium and the drive unit can be achieved, which enables the safe conveyance of, for example, flammable or otherwise reactive or toxic fluids.

Another advantage is that the housing has a flat parting plane between the impeller housing part and the drive housing part. The flat parting plane offers simple and long-lasting sealing options between the housing parts of the pump housing.

Another advantageous design is that a flat seal is arranged between the rotor housing part and the drive housing part. The flat design of the dividing plane between the rotor housing part and the drive housing part enables the use of a flat seal between the housing parts of the pump. A particular advantage here is that flat seals are relatively easy to install, inexpensive, durable and not prone to errors.

An alternative embodiment of the invention provides that an O-ring seal is arranged between the barrel housing part and the drive housing part.

Another advantageous design is that the barrel housing part can be heated. The barrel housing part can therefore also be used to directly heat the rotors placed directly in the barrel housing part. The direct heating of the barrel housing part makes it possible to convey media that are only liquid when heated. This can particularly be plastics, for example MDI plastics.

Figur 1

schematische Darstellung einer erfindungsgemäßen Schraubenpumpe;

Figur 2

weitere schematische Darstellung einer erfindungsgemäßen Schraubenpumpe;

Figur 3

schematische Schnittdarstellung einer erfindungsgemäßen Schraubenpumpe;

Figur 4

weitere schematische Schnittdarstellung einer erfindungsgemäßen Schraubenpumpe;

Figur 5

weitere schematische Schnittdarstellung einer erfindungsgemäßen Schraubenpumpe;

Figur 6

weitere schematische Schnittdarstellung einer erfindungsgemäßen Schraubenpumpe;

Figur 7

schematische Explosionsdarstellung einer erfindungsgemäßen Schraubenpumpe;

Further features, details and advantages of the invention will become apparent from the following description and from the drawings. Embodiments of the invention are shown purely schematically in the following drawings and are described in more detail below. Corresponding objects or elements are provided with the same reference numerals in all figures. They show:

Figure 1

schematic representation of a screw pump according to the invention;

Figure 2

further schematic representation of a screw pump according to the invention;

Figure 3

schematic sectional view of a screw pump according to the invention;

Figure 4

further schematic sectional view of a screw pump according to the invention;

Figure 5

further schematic sectional view of a screw pump according to the invention;

Figure 6

further schematic sectional view of a screw pump according to the invention;

Figure 7

schematic exploded view of a screw pump according to the invention;

In Figure 1 A screw pump 1 is shown schematically with the reference number 1. The illustration according to Figure 1 shows a screw pump 1, which comprises a multi-part housing 2. The housing 2 comprises a running housing part 7 and a connection housing part 15 as well as a drive housing part 21.

In addition to these housing parts 7, 15, 21, further housing part components can be provided for attachment to these housing parts 7, 15, 21. For example, a drain housing can be provided for mounting on the housing parts 7, 15, 21, wherein the drain housing preferably comprises components that enable the screw pump 1 to be drained for maintenance. In addition, an attachment housing with flushing connections for checking and cleaning the screw pump 1 can be provided. A pressure relief valve housing and a bypass housing are also possible for mounting on the modular housing parts 7, 15, 21 of the screw pump 1. A mountable pressure compensation housing with lines for pressure compensation of the screw spindle pump rotors can also be provided on the housing 2 of the screw pump 1. Furthermore, the attachment of a separate recirculation housing can be provided, for example to provide controlled recirculation of fluid when capacity is adjusted. It is also conceivable to provide a safety valve adapter housing as an attachment to the housing parts 7, 15, 21 of the screw pump 1, via which safety valves or bursting disks can be connected. An attachable gear cover is also possible. Other modular additional housings with additional functions are possible. In order to attach the modular additional housings (not shown) to the housing 2 of the screw pump 1, several cover plates 25 are provided on the running housing part 7, which can be removed to install an additional housing. The cover plates 25 also serve to simplify maintenance, since they cover openings into the interior of the pump housing 2, for example to the suction chamber 11. As can be seen in Figure 1 As can be seen, the suction-side connection element 13 and the pressure-side connection element 14 are arranged on a common connection housing part 15 of the multi-part housing 2. The connection housing part 15 is designed in one piece. This facilitates assembly with the other housing parts 7, 21 of the pump 1, since fewer parts have to be aligned with each other. The separate design of the connection housing part 15 makes it possible to change the position of the connection elements 13, 14 on the connection housing part 15 by replacing this component, without any changes to the running housing part 7 being necessary. This makes it possible, for example, to change the conveying direction of the pump 1 without the running housing part 7 having to be adjusted. The connection housing part 15 has a total of four support feet 20 in order to be able to support itself independently from the ground. Foot heating is provided on the support feet 20. The running housing part 7 can be heated using these or other attachable heating elements, e.g. to achieve the desired viscosity of the conveyed fluid. Fluids to ensure.

The Figure 2 shows a screw pump 1 schematically. Compared to Figure 1 the perspective is changed so that a better view of the suction-side connection element 14 is possible.

The Figure 3 shows a schematic sectional view through the housing 2 of a screw pump 1 according to the invention along a rotor 3, 3a of the screw pump 1. The screw pump 1 comprises two coupled, chamber-forming rotors 3, 3a, each with at least one thread-shaped profile 4, 4a formed at least in some areas with screw-shaped channels 5, 5a and with partition walls 6, 6a delimiting the channels 5, 5a. During pumping operation, the rotors 3, 3a rotate in opposite directions about the rotor axes 10, 10a, so that the partition walls 6, 6a of the two rotors 3, 3a mesh with one another like gears. The rotor housing part 7 forms the outer wall for the rotors 3, 3a with a spindle bore 9. The rotors 3, 3a form a plurality of delivery chambers 8, 8a for the fluid to be delivered with the rotor housing part 7. During pumping operation, the delivery chambers 8, 8a move axially along the rotor axes 10, 10a due to the rotation of the rotors 3, 3a. As a result, the fluid is conveyed from a suction chamber 11 into a pressure chamber 12. Even if in the exemplary embodiment only two chamber-forming rotors 3, 3a ( Fig.4 ), the invention is not limited thereto. For example, further rotors can be provided in the screw pump 1. The rotors 3, 3a are mounted in the rotor housing part 7 via bearings 26. For this purpose, receptacles or centerings for the bearing are accommodated in the rotor housing part 7. The one-piece design of the rotor housing part 7 means that the rotors 3, 3a can be aligned and mounted very easily in the rotor housing part 7. The one-piece design of the rotor housing part 7, particularly together with the mounting of the rotors 3, 3a in the rotor housing part 7, offers the option of not having to take additional tolerances caused by other components into account when positioning the rotors 3, 3a. As can be seen, the connection housing part 15 and the rotor housing part 7 together form the suction chamber 11 and the pressure chamber 12. The connection housing part 15 has a partition wall 17 between the suction chamber 11 and the pressure chamber 12. A pressure compensation element 18 is arranged in the partition wall 17, which can divert an overpressure generated in the pressure chamber 12 in the direction of the suction chamber 11 as an overload valve and thus prevent damage to the pump and the pipe system connected to the screw pump 1. Between the rotor housing part 7 and the connection housing part 15, the housing 2 has a flat division plane 16 running parallel to the rotor axes 10, 10a. This division plane 16 forms a connection flange between the connection housing part 15 and the rotor housing part 7. The rotors 3, 3a are driven for pumping operation via a drive 22 arranged in a drive housing part 21 of the multi-part housing 2. This drive 22 comprises a magnetic coupling which is arranged in a drive housing part 21 designed as a flange housing. Between the rotor housing part 7 and the drive housing part 21, a further flat division plane 23 is advantageously provided. A further flat seal 24 is arranged on this division plane 23 between the running housing part 7 and the drive housing part 21. The further add-on additional housings are preferably also connected to the pump housing 2 via planar division planes and are further preferably sealed against one another via further flat seals on these division planes. Further division planes are also possible within the running housing part 7, the connection housing part 15 or the drive housing part 21. Here too, further flat seals are suitable for sealing the housing parts against one another.

The Figure 4 discloses a schematic sectional view through the modular housing 2 of a screw pump 1 according to the invention from the perspective of the rotor axes 10, 10a ( Fig.3 ). The multi-part housing 2 of the screw pump 1 comprises the rotor housing part 7, which encloses the two rotors 3, 3a in an 8-shaped spindle bore 9 without contact. The rotor housing part 7 thus forms the outer wall for the rotors 3, 3a. The rotors 3, 3a form several delivery chambers 8, 8a with the rotor housing part 7 ( Fig.3 ) for the fluid to be pumped. During pumping operation, the pumping chambers 8, 8a ( Fig.3 ) due to the rotation of the rotors 3, 3a axially along the rotor axes 10, 10a ( Fig.3 ). As a result, the fluid is conveyed from the suction chamber 11 into the pressure chamber 12. During pumping operation, the medium to be conveyed is guided from a pipe system connected to the connection element 13 into the suction chamber 11 via a suction-side connection element 13 fluidically connected to the suction chamber 11. A pressure-side connection element 14 fluidically connected to the pressure chamber 12 creates a connection to a pipe system into which the conveyed medium is guided. As shown in the exemplary embodiment, connection flanges 13, 14 can be used as connection elements 13, 14 in this area. The housing 2 has a largely flat parting plane 16 between the rotor housing part 7 and the connection housing part 15, which runs largely parallel to the rotor axes 10, 10a. This division plane 16 forms a connection flange between the connection housing part 15 and the running housing part 7. The connection housing part 15 connects the process connections (suction line, pressure line) on the connection elements 13, 14 with the running housing part 7.

The Figure 5 shows a schematic sectional view of a screw pump 1 according to the invention through the connection housing part 15 and the drive housing part 21 with drive 22. The cutting plane runs parallel to the rotor axes 10, 10a ( Fig.3 ) and division level 16 ( Fig.4 u. 6). It is easy to see that the connection housing part 15 together with the running housing part 7 forms the suction chamber 11 and the pressure chamber 12. The connection housing part 15 has a partition wall 17 between the suction chamber 11 and the pressure chamber 12. This partition wall 17 can be designed differently depending on the requirements at the location where the pump 1 is used, for example in order to adapt the delivery direction of the pump 1.

The Figure 6 shows a schematic sectional view of a screw pump 1 according to the invention through the division plane 16 ( Fig.4 ). As can be seen, the division plane 16 runs through the suction chamber 11 and the pressure chamber 12. It is also clearly visible that between the running housing part 7 and the connection housing part 15 ( Fig.4 ) a flat seal 19 is arranged on the flat parting plane 16. Since the section also runs through the drive housing part 21 and the drive 22, the flat seal 24 located between the housing parts can be seen on the parting plane 23 between the drive housing part 21 and the running housing part 7.

The Figure 7 discloses a schematic exploded view of a screw pump 1 according to the invention. Here, the connection housing part 15 is raised from the running housing part 7, so that the flat seal 19, which is also raised, and the suction chamber 11 and the pressure chamber 12 can be seen.

A particular advantage is that all pump elements can be pre-assembled and tested in the rotor housing part 7 before assembly with the connection housing part 15, including the seals or the magnetic drive.

By arranging several barrel housing parts 7 on top of each other, i.e. stacking the barrel housing parts 7, a multi-stage pump can advantageously be realized.

In addition, several connection housing parts 15 can be provided on several sides of the barrel housing part 7.

Reference list

1

Screw pump

2

Housing

3

3a Rotors

4

4a Profiling

5

5a helical channels

6

6a Partition walls

7

Barrel housing part

8

Conveying chamber

9

Spindle bore

10

10a Rotor axes

11

Suction chamber

12

Printing room

13

suction side connection element

14

pressure-side connection element

15

Connection housing part

16

Division level A

17

partition

18

Pressure compensation element

19

Flat gasket A

20

Support foot

21

Drive housing part

22

drive

23

Division level B

24

Flat gasket B

25

Cover plate

26

Warehouse

Claims (16)

1. Screw pump (1), in particular a single flow or multiflow double screw pump, comprising a multi-part housing (2, 7, 15, 21) and at least two coupled rotors (3, 3a) that form a chamber and respectively have at least one thread-shaped profiling (4, 4a) at least in regions with screw-shaped ducts (5, 5a) and with delimiting surfaces (6, 6a) that delimit the ducts (5, 5a), wherein the rotors (3, 3a) exert a rotor rotation in opposite directions and the delimiting surfaces (6, 6a) engage into one another in a gear wheel-like manner, a screw housing part (7), wherein the screw housing part (7) encompasses the rotors (3, 3a) in a contactless manner, wherein the rotors (3, 3a) form at least one conveying chamber (8, 8a) with the screw housing part (7) for the fluid that is to be conveyed, wherein the conveying chamber (8, 8a) migrates axially along the rotor axes (10, 10a) and conveys the fluid from a suction chamber (11) into a pressure chamber (12), a suction-side connecting element (13) that is connected in a fluid-technical manner to the suction chamber (11) and a pressure-side connecting element (14) that is connected in a fluid-technical manner to the pressure chamber (12),
   characterised in that
   the suction-side connecting element (13) and the pressure-side connecting element (14) are arranged on a connecting housing part (15) of the multi-part housing (2, 7, 15, 21), wherein the housing (2, 7, 15, 21) comprises a planar dividing plane (16) that extends parallel to the rotor axes (10, 10a) between the screw housing part (7) and the connecting housing part (15), wherein at least one supporting base (20) is provided on the connecting housing part (15).
2. Screw pump (1) according to Claim 1, characterised in that the dividing plane (16) extends through the suction chamber (11) and the pressure chamber (12).
3. Screw pump (1) according to Claim 1 or 2, characterised in that the rotors (3, 3a) are mounted in the screw housing part (7).
4. Screw pump (1) according to one of Claims 1 to 3, characterised in that the screw housing part (7) is formed as a single part.
5. Screw pump (1) according to one of Claims 1 to 4, characterised in that the connecting housing part (15) is formed as a single part.
6. Screw pump (1) according to one of Claims 1 to 5, characterised in that the connecting housing part (15) together with the screw housing part (7) forms the suction chamber (11) and the pressure chamber (12).
7. Screw pump (1) according to one of Claims 1 to 6, characterised in that the connecting housing part (15) comprises a dividing wall (17) between the suction chamber (11) and the pressure chamber (12).
8. Screw pump (1) according to one of Claims 7, characterised in that a pressure equalising element (18) is arranged in the dividing wall (17).
9. Screw pump (1) according to one of Claims 1 to 8, characterised in that a flat seal (19) is arranged between the screw housing part (7) and the connecting housing part (15).
10. Screw pump (1) according to one of Claims 1 to 8, characterised in that an O-ring seal is arranged between the screw housing part (7) and the connecting housing part (15).
11. Screw pump (1) according to one of Claims 1 to 10, characterised in that the rotors (3, 3a) can be driven via a drive (22) that is arranged in a drive housing part (21) of the multi-part housing (2, 7, 15, 21).
12. Screw pump (1) according to Claim 11, characterised in that the drive (22) comprises a magnetic coupling.
13. Screw pump (1) according to Claim 11 or 12, characterised in that the housing (2, 7, 15, 21) comprises a dividing plane that extends in a planar manner between the screw housing part (7) and the drive housing part (21).
14. Screw pump (1) according to one of Claims 11 to 13, characterised in that a flat seal (24) is arranged between the screw housing part (7) and the drive housing part (21).
15. Screw pump (1) according to one of Claims 11 to 13, characterised in that an O-ring seal is arranged between the screw housing part (7) and the drive housing part (21).
16. Screw pump (1) according to one of Claims 1 to 15, characterised in that the screw housing part (7) can be heated.

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