DE102005039618A1 - Eccentric spiral pump for conveying shear sensitive media, has housing with two areas that are sealed against one another by sealing unit implemented in rotor drive shaft, which is arranged inside hollow shaft, which implements sealing unit - Google Patents

Abstract

The pump has a housing with area (13, 14) turned towards and away from a product, respectively. The areas are sealed against one another by a sealing unit (15), which is implemented in a rotor drive shaft (8) for driving a rotor unit (5). The rotor drive shaft is arranged inside a hollow shaft (12), which implements the sealing unit. The hollow shaft is connected with a motor drive shaft in the area (14) in a torque proof manner.

Description

State of technology

The The invention relates to an eccentric screw pump according to the preamble of claim 1.

to advancement from liquid or viscous conveyed are known a variety of positive displacement pumps. For one Series of use cases, in which especially shear-sensitive media are gently promoted have to, find eccentric screw pumps or so-called Mohnopumpen use. The eccentric screw pump has a trained as a single-flight screw Rotor up, moving in a fixed stator with a hollow volume in the form of a two-string The worm turns, with the rotor over a propeller shaft is connected to the drive. They are based on the course differences cyclically opening and closing Chambers between the rotor and stator suck the conveyed material and press it on a helical conveying through the pump and give the conveyed on the pressure side. The eccentric screw thus causes a uniform bumpless promotion of the conveyed goods.

The Materials of the pump components hang in Essentially on the type of good to be promoted. The rotor is usually made of steel, the stator to the pumping chamber usually through an elastomer is formed.

at suitable dimensioning or selection of the pump components can a particularly gentle promotion of the conveyed goods be achieved, which is particularly common in food technology Advantage is.

In addition, will in food technology relatively high demands on the cleaning option the eccentric screw pump, with a simple installation or disassembly of the eccentric screw pump is helpful. In addition, can by exchange of rotor or stator, the capacity of the eccentric screw pump be made flexible in a relatively wide range.

Especially when used in food technology is next to the gentle Promotion of Medium mandatory that the entire system and therefore also The pump used there meets the indispensable hygiene requirements.

A Such pump must therefore, as o.a. be easily accessible to a cleaning. The cleaning is usually through targeted use and combination of mechanical and chemical Tools made. For Cleaning is the choice of materials and the structural design the pump of vital importance. The with the pumped medium in touch coming pump components be provided with appropriate materials that are food compatible and a on the other resistant to appropriate cleaning chemicals are.

Of the constructive structure must ensure that no flow dead zones and with it the possibility for deposits and resulting herd germs can occur. The avoidance of dead zones is on the one hand when changing the batch of the product and on the other hand in the cleaning of importance. There are once for the cleaning the possibility of the with pumped medium coming in contact Rinse parts of the pump with a cleaning medium or but also to disassemble the pump and the individual components of a cleaning to undergo.

The Disassembly of the pump for cleaning purposes is inevitable at appropriate intervals, not least for a visual inspection of the cleaning result.

For the decomposition The pump has corresponding interfaces both in the area of pump housing as well as to provide between the individual rotor elements. Especially the joints of individual rotor elements are endangered areas for the Emergence of dead zones, in which not subsidized Can accumulate medium. About that In addition, such joints between individual rotor elements by the arrangement within the product facing area of the pump housing poorly accessible and after the promotion a conveyed medium polluted by this. Disassembling the pump, especially the Rotor elements, designed for this reason, often difficult.

Task and Advantages of the invention

task the invention it is in contrast, a To propose progressing cavity pump, in which the disassembly, in particular the rotor unit is facilitated.

These Task is starting from an eccentric screw the introductory mentioned type by the characterizing features of claim 1 solved.

By in the subclaims mentioned measures are advantageous embodiments and further education possible.

Accordingly, an eccentric screw pump according to the invention is characterized in that a rotor drive shaft, which is provided for driving the rotor unit and which passes through a product-facing and product-remote area in the interior of the pump housing separating sealing unit is disposed within a sealing unit also passing through the hollow shaft.

By This measure Is it possible, a non-rotatable connection of the rotor drive shaft in the product facing away Be provided where the interface is always clean, i.e. free from the subsidized Product or medium is, and on the other by appropriate measures easily accessible for the Disassembly can be formed. The entire rotor unit can after loosening This junction are removed in the axial direction. The Rotor drive shaft leaves in this case through the hollow shaft to the product side facing out pull out.

In an advantageous embodiment the invention, the hollow shaft is rotatably with a motor drive shaft a drive motor of the pump connected. In this way results itself with appropriate connection of the rotor drive shaft with the drive motor a rotation of the hollow shaft without relative movement with the rotor drive shaft. In this way there is the advantage that the sealing unit, the rotating components of the rotor unit with respect to the stationary Components of the pump housing seals, outside the hollow shaft is to be arranged. This facilitates the disassembly considerably, as when removing the rotor unit with removal of the Rotor drive shaft from the hollow shaft arranged outside the hollow shaft seal unit between hollow shaft and pump housing from disassembly of the rotor unit remains unaffected.

In a development of the invention will continue to be a rotationally fixed Connection between the hollow shaft and the rotor drive shaft in arranged product-remote area of the pump housing. The drive the rotor unit or the rotor drive shaft takes place in this embodiment immediately above the hollow shaft. The release The rotor unit can in the product remote area by separating the connection between the hollow shaft and the rotor drive shaft.

In a preferred embodiment of this embodiment, the rotationally fixed Connection between the rotor drive shaft and the hollow shaft through a housing window of the pump housing accessible made. As a result, the disassembly of the rotor unit is further simplified, because the separation of the connection can be made without any work steps on housing parts or disassembly of the drive motor is required.

Preferably the interior of the hollow shaft is sealed against the pump interior. This is especially true when using the pump in the food industry beneficial to the formation of a corresponding dead space inside the hollow shaft and the associated risk of contamination to prevention.

The Rotor drive shaft is in a particular embodiment with further rotor elements rotatably connected. Such a further rotor element can as in a conventional structure an eccentric screw pump e.g. a cardan shaft or a Be bending bar. Such rotor elements are required to the allow eccentric movement of the pump rotor in its rotation.

In a development of this embodiment This is rotatable connection between the rotor drive shaft and the rotor element also with a sealing element for sealing the non-rotatable connection opposite provided the pump interior. Such a seal prevents in the area of this junction, in turn, the formation of dead space with the disadvantages described above.

In a particularly advantageous embodiment of the invention with a sealing element that seals the non-rotatable connection between Rotor drive shaft and rotor element is provided, at the same time the Hollow shaft opposite the pump interior sealed. By this measure, the structure of Pump simplified. In particular, this will reduce the number of required Parts reduced.

advantageously, At least the rotor drive shaft is completely in the region facing away from the product the pump interior arranged. As a result, e.g. the assembly and / or disassembly of the eccentric screw pump or individual components this one such as e.g. especially the rotor drive shaft or von / all Drive components and / or the rotor or in the product facing Area arranged components can be improved.

Preferably is the hollow shaft together with the sealing unit, in particular by means one or more sealing elements, as a separation unit for separating formed of the product-facing portion of the product facing away from area.

In general, it is advantageous to design the sealing unit in such a way that it allows sealing of rotating elements during operation relative to elements that are not rotating or static during operation. This is elegantly the complete separation of the product facing area of product-remote area safely ensured. This guarantees that no product can get into the area away from the product, which further improves its use in hygienically sensitive applications such as in the food sector.

In a particular embodiment becomes a cover sleeve for the non-rotatable connection between the pump drive shaft and the rotor element such as a cardan shaft provided. By means of a such cover sleeve Is it possible, the sealing of the inside of this sleeve connection point to the pump interior in the region of the outlet of the pump drive shaft made from the hollow shaft and thus at this point by means a sealing element such as an O-ring or the like both the Sealing the located inside the cover sleeve fasteners between rotor drive shaft and rotor element, e.g. a cardan shaft, as well as the hollow shaft opposite To seal the pump interior.

For the non-rotatable Connection between the hollow shaft and the rotor drive shaft is advantageously provided a bolt having a recess in the hollow shaft and / or a recess in the rotor drive shaft at least partially interspersed.

One such a bolt can be formed, for example, as a pin, the aligned recesses in the hollow shaft and the rotor drive shaft at least partially interspersed. Such a pin connection is accurate and with high torque transmission feasible, wherein especially in connection with a cover as described above, an undesirable Loosen or even the loss of the pen possible is.

embodiment

One embodiment The invention is illustrated in the drawing and is based on the Figures explained in more detail below.

in the Show individual:

1 FIG. 2: a schematic section through a complete eccentric screw pump, FIG.

2 : a schematic enlarged detail in the transition from the product-facing to the product-facing region,

3 FIG. 2 is a schematic side view of a section of the pump. FIG.

4 : a further, schematic side view of the same section from another viewing direction,

5 : A schematic section through a section of another eccentric screw pump with a rotor drive shaft in operational position and

6 : a schematic section through a section of the further eccentric screw according to 5 with an axially slightly displaced rotor drive shaft in disassembly position.

The eccentric screw pump 1 according to 1 includes a pump housing 2 made of various housing elements such as the stator 3 and the suction housing 4 is composed. Inside the case 2 is a rotor unit 5 housed, consisting of various rotor elements, such as the worm rotor 6 a cardan shaft 7 and the pump drive shaft 8th consists. The rotor drive shaft 8th is in the manner explained in more detail below with the drive motor 9 positively coupled.

In the image section according to 2 is the motor-side part of the sow housing 4 with suction nozzle 10 as well as an attachment housing 11 for fastening the drive motor 9 shown enlarged with the components contained therein.

In particular, this is clearly visible that the with the cardan shaft 7 connected rotor drive shaft 8th a hollow shaft 12 interspersed. The hollow shaft 12 extends from the sow housing 4 into the mounting housing 11 into it.

The interior of the pump housing 2 is approximately in the range of the connection between the suction housing 4 and the attachment housing 11 into a product-facing area 13 and a product-facing area 14 divided.

Accordingly, all come in the product-facing area 13 with the interior of the pump housing 2 or of the suction housing 4 in contact with the components to be conveyed product in contact, while in Produktabgewandten space 14 a contact with the fluid or product to be delivered due to the separation of the two areas 13 . 14 is avoided.

The separation of the areas 13 . 14 done by a sealing unit 15 , In the concrete present embodiment, a static sealing sleeve 16 and a rotating sealing ring 17 includes.

The rotating sealing ring 17 is hereby a diaphragm spring 18 that with a sliding sleeve 19 is covered, in the axial direction of the static sealing sleeve 16 pressed. This is a seal between realized rotating rotating and static non-rotating components in an advantageous manner.

The rotating sealing ring 17 is precisely in a corresponding recess of the sliding sleeve 19 inserted at the opposite end via an O-ring 20 at one with the hollow shaft 12 connected further sliding sleeve 21 is sealed.

The static sealing sleeve 16 is over an O-ring 22 opposite a ring projection 23 one in the suction housing 4 protruding tube insert 24 sealed, in turn, the front side of a corresponding annular shoulder 25 of the sow housing 4 by means of an O-ring 26 is sealed. About the above-described components and in particular as sealing elements provided O-rings 16 to 26 is the product facing area 13 tight for the pumped medium from the product facing away area 14 separated.

The seals or sealing elements 15 . 16 . 17 . 20 . 22 . 26 . 36 . 37 allow in an advantageous manner with the hollow shaft 12 together a hermetically sealed separation of the product facing area 13 or the drive components to the region facing away from the product 14 or the driven components even during operation. It will be a complete separation of the areas 13 and 14 realized. As a result, assembly or disassembly of individual components of the pump such as the drive components, in particular the rotor drive shaft, and / or the driven components, in particular the rotor unit 5 or the stator 3 , the snail rotor 6 , etc. in a particularly simple manner.

The hollow shaft 12 is inside the attachment housing 11 via a connecting pin 27 , the aligned holes 28 . 29 in the hollow shaft 12 and the rotor drive shaft 8th interspersed, rotatably connected. The hollow shaft 12 is in the motor-side area of the attachment housing 11 in a conventional manner with the motor drive shaft 30 rotatably connected. Thus, the adhesion between the motor drive shaft 30 up to the rotor drive shaft 8th over the hollow shaft 12 produced.

In the mounting housing 11 are two opposite windows 31 . 32 attached, about after loosening a locking screw 39 an annular sleeve 40 is rotatable until the bore 28 the hollow shaft 12 and thus also the connecting pin 27 is accessible from the outside.

By loosening the connecting pin 27 for example, through the window 31 with a suitable tool from the holes 28 . 29 pushed out and through the opposite window 32 can be removed, therefore, the rotor unit can be 5 from the hollow shaft 12 and remove in the direction of arrow P. The hollow shaft 12 remains with everyone to the seal unit 15 belonging circumferentially arranged components in the illustrated mounted position. The disassembly of the rotor unit 5 is thus considerably simplified.

In the illustration according to 2 is still recognizable that the connection between the rotor drive shaft 8th and the cardan shaft 7 also by a connecting pin 33 is realized, the corresponding holes in the tail 34 the cardan shaft 7 and the rotor drive shaft 8th interspersed.

This connecting pin 33 and the associated holes in the rotor drive shaft 8th or the tail 34 are through a cover sleeve 35 covered. Two O-rings 36 . 37 seal the interior of the cover sleeve 35 opposite the product facing area 13 of the sow housing 4 from. The O-ring 37 is in an annular shoulder 38 of the tail 34 inserted and is under elastic positive locking on the front side of the hollow shaft 12 tight and firmly connected sliding sleeve 21 at. Thus, over this O-ring 37 and the cover sleeve 35 also the hollow shaft 12 opposite the interior of the suction housing 4 in the product facing area 13 of the pump housing 2 sealed.

The pump described with reference to the figures represents an embodiment in which the product facing area 13 Dead spaces and thus the associated disadvantages such as pollution and microbial contamination are largely prevented.

The disassembly of the rotor unit 5 is due to the embodiment of the invention with rotor drive shaft 8th and hollow shaft 12 considerably relieved.

The connection to be disassembled 27 . 28 . 29 is located in the product-remote area and is thus always accessible free of the product to be conveyed. This connection can also be in the dirty state of the pump 1 be solved easily to the rotor or the entire rotor unit 6 , eg for cleaning in the direction of arrow P to remove.

The window 31 . 32 in the attachment housing 11 of the pump housing 2 facilitate the accessibility of the connection 27 . 28 . 29 additionally.

The adhesion between the rotor drive shaft 8th and motor drive shaft 30 takes over the hollow shaft 12 instead, so with the release of the connection 27 . 28 . 29 between rotor drive shaft 8th and hollow shaft 12 also the connection to the motor drive shaft 30 is solved.

All sealing elements that are the product facing area 13 from the product remote area 14 can complete when dismantling the rotor unit 5 remain at their place of installation. This applies in particular to those on the outer circumference of the hollow shaft 12 arranged construction and sealing elements, especially for the static sealing sleeve 16 as well as the rotating sealing ring 17 , The sealing of the hollow shaft 12 can when reinserting the rotor unit 5 in a simple way together with the sealing of the connection 33 . 34 . 35 be made, as this with reference to the embodiment using the O-ring 37 is shown.

In the 5 and 6 a further variant of a pump according to the invention is shown schematically. An essential difference to the variant listed above is that their rotor drive shaft 8th something is extended and at least two holes 41 and 42 has, by means of which and a pin not shown here 27 (see. 2 ) a fixation with the engine 9 or the motor drive shaft 30 , in particular by means of the bore 28 the hollow shaft 12 can be done.

In 5 is the hole 41 the rotor drive shaft 8th in alignment with the bore 28 the hollow shaft 12 arranged so that both components 8th . 12 by means of the pen 27 (in 2 shown) can be fixed. This corresponds to the operational position of the pump.

In contrast, in 6 the hole 42 the rotor drive shaft 8th in alignment with the bore 28 the hollow shaft 12 arranged so that both components 8th . 12 by means of the pen 27 (in 2 shown) can be fixed. This corresponds to a disassembly position of the pump. 6 clarifies that in this position, for example, the worm rotor 6 completely out of the case 4 protrudes and thus can be easily dismantled. The fixation of the rotor drive shaft 8th with the hollow shaft 12 by means of the pen 27 allows, for example, the worm rotor 6 from the cardan shaft 7 can be unscrewed.

Preferably, the hollow shaft 12 as a guide element 12 for guiding an axial adjustment of the rotor drive shaft 8th educated. As a result, the assembly or disassembly of the pump or the rather abrasive rotor unit 5 especially simplified. For example, the housing 4 remain fixed to a corresponding machine, supporting structure or a room, etc. and the rotor unit 5 or the snail 6 like in particular in 6 shown easily and very quickly disassembled or mounted. This is especially true for relatively large pumps 1 of very special advantage.

Without further explanation, the drive unit or the motor 9 including his wave 30 from the case 2 be separated, without that in this case, the rotor unit 5 impaired or dismantled.

The variant according to the 5 and 6 is characterized by its very maintenance-friendly training very special.

In addition, the variant according to 5 respectively. 6 one as a cuff 43 trained seal 36 or in 2 as an O-ring 36 trained sealing element. The cuff 43 essentially extends over the universal joint and thereby elegantly prevents soiling of these components by the product to be pumped. The cuff 43 extends from cover sleeve 35 to cover sleeve 35 without these in the 5 . 6 are shown in more detail. Thus, seals the cuff 43 also the cover sleeves 35 from. With the cuff 43 is advantageously the formation of dead spaces in the pump housing 4 advantageously prevented or reduced.

The illustrated pumps are only as an example of facilitating disassembly of the rotor unit 5 listed.

Other designs are conceivable without further notice. It is advantageous, however, that the pump drive shaft 8th a hollow shaft 12 interspersed, extending from the product facing area 13 up to the product-remote area 14 of the pump housing 2 extends.

1

Cavity Pump

2

casing

3

stator

4

Suction housing

5

rotor unit

6

screw rotor

7

cardan shaft

8th

Rotor drive shaft

9

drive motor

10

suction

11

mounting housing

12

hollow shaft

13

product-facing Area

14

product averted Area

15

sealing unit

16

static sealing sleeve

17

rotating seal

18

Belleville spring

19

sliding sleeve

20

O-ring

21

sliding sleeve

22

O-ring

23

annular projection

24

tube insert

25

annular shoulder

26

O-ring

27

connecting pin

28

drilling

29

drilling

30

Motor drive shaft

31

window

32

window

33

connecting pin

34

tail

35

cover sleeve

36

O-ring

37

O-ring

38

annular shoulder

39

locking screw

40

ring sleeve

41

drilling

42

drilling

43

cuff

Claims (13)

An eccentric screw pump having a pump housing which has a product-facing and a Produktabgewandten area in the interior, wherein the two areas are sealed by a seal unit comprising one or more sealing elements against each other and wherein a sealing unit passing through the rotor drive shaft for driving a rotor unit is provided, characterized in that the rotor drive shaft ( 8th ) within a sealing unit ( 15 ) passing hollow shaft ( 12 ) is arranged. Pump according to claim 1, characterized in that the hollow shaft ( 12 ) rotatably with a motor drive shaft ( 30 ) of a drive motor ( 9 ) connected is. Pump according to one of the preceding claims, characterized in that a rotationally fixed connection ( 27 . 28 . 29 ) between the hollow shaft ( 12 ) and the rotor drive shaft ( 8th ) in the product-remote area ( 14 ) of the pump housing ( 2 ) is arranged. Pump according to one of the preceding claims, characterized in that the rotationally fixed connection ( 27 . 28 . 29 ) between the rotor drive shaft ( 8th ) and the hollow shaft ( 12 ) through a housing window ( 31 . 32 ) of the pump housing ( 2 ) is accessible. Pump according to one of the preceding claims, characterized in that the hollow shaft ( 12 ) towards the product-facing area ( 13 ) of the pump interior is sealed. Pump according to one of the preceding claims, characterized in that a rotationally fixed connection ( 33 ) between the rotor drive shaft ( 8th ) and a rotor element ( 7 ) of the rotor unit ( 5 ) is provided. Pump according to one of the preceding claims, characterized in that as a rotor element, a bending rod or a cardan shaft ( 7 ) is provided. Pump according to one of the preceding claims, characterized in that the rotationally fixed connection ( 33 ) between the rotor drive shaft ( 8th ) and the rotor element ( 7 ) by means of a sealing element ( 35 . 36 . 37 ) towards the product-facing area ( 13 ) of the pump interior is sealed. Pump according to one of the preceding claims, characterized in that a sealing element ( 37 ) for sealing the rotationally fixed connection ( 33 ) at the same time the hollow shaft ( 12 ) towards the product-facing area ( 13 ) of the pump interior seals. Pump according to one of the preceding claims, characterized in that at least the rotor drive shaft ( 8th ) completely in the non-product area ( 13 ) of the pump interior is arranged. Pump according to one of the preceding claims, characterized in that a covering sleeve ( 35 ) for covering and securing the non-rotatable connection ( 33 ) between the rotor drive shaft ( 8th ) and the rotor element ( 7 ) is provided. Pump according to one of the preceding claims, characterized in that the rotationally fixed connection ( 27 . 28 . 29 ) between the hollow shaft ( 12 ) and the pump drive shaft ( 8th ) a bolt ( 27 ) comprising a recess ( 28 ) of the hollow shaft ( 12 ) and / or a recess ( 29 ) of the rotor drive shaft ( 8th ) at least partially positively interspersed. Pump according to one of the preceding claims, characterized in that the rotationally fixed connection between the hollow shaft ( 12 ) and the rotor drive shaft ( 8th ) a connecting pin ( 27 ) comprising a recess ( 28 ) in the hollow shaft ( 12 ) and an aligned recess ( 29 ) in the rotor drive shaft ( 8th ) at least partially enforced.