EP2634366B1 - Dual spindle helical spindle pump with a single-entry design - Google Patents

Description

The invention relates to a two-spindle screw pump in a single-flow design with a pump housing which has a pump section, a bearing section and a gear section with a gear room, the bearing section and the pump section being designed separately from one another, with a delivery housing part as part of the pump section, in which two Shafts arranged conveyor screws with flanks are provided, the shafts being mounted in the bearing section and extending into the gear section, with gears arranged on the shafts in the gear section, by means of which the shafts are rotationally coupled, with a fastening element arranged on the shaft in operative connection with these Establishing a holding connection between the shaft and the gear, the fastening element and the gear having corresponding bores via which a holding connection can be established between the gear and the fastening element via a locking element, the screw spindle pump being mountable on a drive module.

The conveyor screws arranged on the shafts are fastened with a defined clearance between the flanks (backlash).

Such a pump structure is known from DE 20 2009 014 604 U1 and WO 2004 053 333 A1 . These pumps are particularly characterized by product-friendly operation and the associated low wear. There are no connections between such pumps and a drive module via a gearbox EP 0 096 666 A1 known.

There is a need for improvement in that the effort involved in maintaining the pumps should be reduced. This occurs in particular when the conveyor screws or mechanical seals are replaced due to wear and the backlash needs to be readjusted. For this purpose, it is currently necessary that the gearbox and bearing section of the pump must also be detached from the drive in order to then be able to adequately adjust the backlash of the delivery screws. Such an approach is, among other things, US 2,641,937 A and DE 263 72 21 A1 shown.

An alternative setting option for the backlash is available EP 1 054 160 A1 shown. The rotor shafts are each driven by their own electric motors. The angular positions of the shafts are determined using resolvers, which are used to electronically synchronize the rotors.

The object of the invention is to improve the aforementioned pump of the preamble in such a way that simpler and less time-consuming maintenance or readjustment can be carried out.

The problem is solved in that the holes in the fastening element are designed in such a way that the gear and the fastening element can be rotated relative to one another, so that a distance between the flanks of the delivery screws can be adjusted, and that an opening is provided on the gear section of the pump housing, so that the opening with a detachable cover is provided, that the opening is arranged in such a way that the cover is detachable in the mounted state of the spindle pump when the screw spindle pump is mounted on the drive module, that the gear room for adjusting the backlash of the delivery screws can be reached with the necessary tools, and that the holes in the fastening element are provided as an elongated hole in the circumferential direction with a center line with a constant radius, in which the locking element is displaceable in the inserted but not locked state, and that the length of the elongated hole in the circumferential direction is provided such that its When moving the locking element in the slot, the end points must at least match the contact points of the flanks of the conveyor screws.

By providing the opening in the housing, it is possible to significantly reduce the time required for spindle readjustment because it is no longer necessary to dismantle the gear housing to expose the gear chamber and it is also not necessary to dismantle the drive module. The maintenance and adjustability of the spindle pump are improved by the fact that it is possible to adjust the entire backlash of the delivery screws by providing the elongated hole. Previously it was necessary that the gear wheel had to be removed from the shaft and repositioned in a twisted manner in order to be able to adjust the backlash adequately. This setting effort is thereby significantly reduced.

A further teaching of the invention provides that the fastening element with the elongated holes is only provided on one shaft. This takes into account the fact that it has been found that it is sufficient to simply adjust one shaft while the other shaft is constantly mounted.

A further teaching of the invention provides that there is a hydraulic separation between the pump section and the bearing section, preferably via a mechanical seal and/or that there is a spatial separation between the bearing section and the gear section. These spatial separations have proven to be particularly advantageous with regard to the adjustability of the backlash and the bearing.

Furthermore, it is advantageous that the fastening element has a socket section for sliding onto the shaft, the socket section preferably having a receiving section for the gear, and/or the shaft and the socket section having a groove for receiving a key to produce a rotationally effective connection between the shaft and have fastening element. This embodiment element represents a cost-effective and particularly maintenance-friendly embodiment of the invention.

Fig. 1a

eine Schnittansicht durch eine erfindungsgemäße Pumpendraufsicht,

Fig. 1 b

eine vergrößerte Ausschnittansicht zu Fig. 1 a,

Fig. 2

eine Schnittansicht einer erfindungsgemäßen Pumpe in Schnittansicht durch den Getriebeabschnitt,

Fig. 3

eine Schnittansicht durch die Förderschrauben,

Fig. 4

eine räumliche Ansicht einer ersten Ausführungsform einer erfindungsgemäßen Pumpe mit Antrieb,

Fig. 5

eine Seitenansicht zu Fig. 4,

Fig. 6

eine Draufsicht zu Fig. 4,

Fig. 7

eine Draufsicht auf den Getriebeabschnitt zu Fig. 1 in Ausführung zu Fig. 4,

Fig. 8

eine räumliche Ansicht einer zweiten Ausführungsform,

Fig. 9

eine Seitenansicht zu Fig. 8,

Fig. 10

eine Draufsicht zu Fig. 8 und

Fig. 11

eine Draufsicht des Getriebeabschnitts zu Fig. 1 in Ausführung zu Fig. 8.

A further advantageous embodiment of the invention is that the bores of the gear are designed as a hole with a threaded section, and / or that in the Holes a locking element in the form of a screw can be used, via which the holding connection can be established. Furthermore, it is advantageous that a hole is provided in the shaft head, into which a locking element can be inserted so that the fastening element is locked against the shaft, preferably with a clamping disk. The invention is explained in more detail below using an exemplary embodiment in conjunction with a drawing. Show:

Fig. 1a

a sectional view through a pump top view according to the invention,

Fig. 1 b

an enlarged detail view Fig. 1 a,

Fig. 2

a sectional view of a pump according to the invention in a sectional view through the gear section,

Fig. 3

a sectional view through the conveyor screws,

Fig. 4

a spatial view of a first embodiment of a pump according to the invention with drive,

Fig. 5

a side view Fig. 4 ,

Fig. 6

a top view Fig. 4 ,

Fig. 7

a top view of the gear section Fig. 1 in execution too Fig. 4 ,

Fig. 8

a spatial view of a second embodiment,

Fig. 9

a side view Fig. 8 ,

Fig. 10

a top view Fig. 8 and

Fig. 11

a top view of the transmission section Fig. 1 in execution too Fig. 8 .

Fig. 1a and Fig. 1b show a sectional view in plan view of a spindle pump 10 according to the invention. The spindle pump 10 has a housing 11 which has a pump section 12, a bearing section 13 and a gear section 14. These are spatially and hydraulically separated from each other. Furthermore, the spindle pump 10 comprises a driven shaft 15 and a driven shaft 16. A delivery screw 17 is arranged on the driven shaft 15 and a delivery screw 18 is arranged on the driven shaft 16, which are in engagement. A needle bearing 19 and a roller bearing 20 are provided in the bearing section 13, so that the shafts are mounted in external bearings outside the pump section 12. The shaft ends 22, 23 are located in the gear room 21. The shaft end 22 of the driven shaft 15 extends out of the housing 11 and has a connection 24 for a drive unit 49 there. On the driven shaft 15 there is a gear 25. On the driven shaft is a gear 26 is arranged. The teeth of the gears 25, 26 are in meshing engagement.

A fastening element 27 is arranged on the shaft end 23 of the driven shaft 16. The fastening element 27 has a socket section 28 and a flange section 29. The outside of the socket section 28 is also a receiving surface 30 for the gear 26. A key 31 is inserted into a groove (not shown) in the shaft end 23 and in the fastening element 27, via which a rotary connection between the shaft 16 and the fastening element 27 is established. A hexagonal screw 33 is screwed into a hole (not shown) in the end face 32 of the shaft end 23, with which a tension washer 34 is screwed against a seat 35 on the fastening element 27. As a result, the fastening element 27 is connected to the shaft end 23 in a locking manner. The flange section 29 has a bore 36. The gear 26 has a corresponding bore 37, which can be designed as a through bore or as a hole bore. A thread (not shown) is arranged in the bore 37. A hexagonal screw 38 is screwed into this thread, whereby the flange section 29 of the fastening element 27 is locked with the gear 26. Behind the socket section 28 of the fastening element 27 there is a spacer bushing 39, which ensures that the gear 26 cannot come into contact with the bearing section 13 with the fastening screws 40 of the gear section 14.

In Fig. 2 a sectional view through the gear section 14 is shown. The meshing gears 25, 26 can be seen. The fastening element 27 with its flange section 29 is shown on the gear 26. The clamping disk 34 is mounted in the seat 35 of the flange section 29 via the hexagonal screw 33. The bore 36 in the flange section 29 is designed as an elongated hole 41. Furthermore, the gear section 14 has an opening 42 on its upper side, which is connected to the gear section 14 in a holding manner with a cover 43 via hexagonal screws 44.

Fig. 3 shows a sectional view through the engaged conveyor screws 17, 18. The conveyor screws have screw projections 45, each of which has flanks 46. The distance between the flanks 46 represents the backlash 47. By turning the driven shaft 16 and thus the conveyor screw 18, while the driven shaft 15 and thus the conveyor screw 17 are stationary, the backlash 47 changes in such a way that it becomes larger on one side and smaller on the other side of the screw projection 45. The optimal arrangement of the conveying screws 17, 18 is such that the flank clearances on both sides of the screw projections 45 are the same size.

The backlash 47 is therefore adjusted in such a way that the fastening element 27 is arranged in a rotationally fixed manner on the shaft end 23 or the driven shaft 16 via the key 31. The tension washer 34 is then screwed into the seat 35 using the hexagon screw 33. At this point, the gear 26 is already located on the receiving surface 30 of the socket section 28 of the fastening element 27 and is in engagement with the gear 25 of the driven shaft 15. To adjust the backlash, the flange section 29 with the elongated holes 41 located therein is now placed over the bores 37 is arranged in the gear 26 and the hexagon screws 38 are screwed in, with no locking connection between the flange section 29 and the gear 26 being created. By turning the flange section 29, it is now possible to adjust the backlash 47 between the conveying screw 18 and the conveying screw 17. Once the optimal setting of the backlash 47 has been achieved, a locking connection is created via the hexagon screws 38.

Fig. 4 to Fig. 7 show an arrangement of the spindle pump 10 on a base plate 48. The spindle pump 10 is connected to a drive unit 49. Fig. 8 to Fig. 11 show a further embodiment in which the pump has a block design. In Fig. 7 and Fig. 11 Top views of the gear section 14 are shown without the cover 43 mounted on the opening 42. The gear section 14 has a flat section 50 in which holes 51 are arranged around the opening 42 and have a thread (not shown) into which the hexagon screws 44 are screwed.

If it is necessary to readjust the backlash 47 due to maintenance work, for example on the mechanical seal, wear or due to a change of the conveyor screws 17, 18, it is possible by removing the hexagon screws 44 and removing the cover 43 through the opening 42 into the gearbox room 21 to intervene with a tool (not shown). It is possible, for example, to loosen the hexagon screws 38 in order to prevent the driven shaft 16 from rotating via the gear 26 and thus readjust the backlash 47. After the backlash has been adjusted, the hexagon screws 38 are then tightened again and the cover 43 with the hexagon screws 44 is placed back on the flat section 50 by inserting the hexagon screws 44 into the bore 51 and made ready for operation.

It is therefore no longer necessary to detach the drive units 49 and/or the gear section 14 of the housing 11. Furthermore, thanks to the elongated holes 41, it is no longer necessary to remove the gear 26 from the shaft 16 in a laborious manner, then rotate the gear 26 around a circular section until the next hole 36 is aligned, and then put the gear 26 back on the shaft 16 the backlash 47 is difficult to set.

List of reference symbols:

10 Spindle pump 42 opening 11 Housing 43 Lid 12 Pump section 44 Hex bolt 13 Storage section 45 screw projection 14 Transmission section 46 Flank 15 driven shaft 47 Cross play 16 driven wave 48 base plate 17 conveyor screw 49 Drive unit 18 conveyor screw 50 plan section 19 Needle bearings 51 drilling 20 Roller bearings 21 Transmission room 22 shaft end 23 shaft end 24 Connection 25 gear 26 gear 27 fastener 28 Bushing section 29 flange section 30 Recording surface 31 Adjusting spring 32 face 33 Hex bolt 34 tension washer 35 Seat 36 drilling 37 drilling 38 Hex bolt 39 Spacer bushing 40 Fastening screw 41 Long hole

Claims (6)

1. Two-spindle screw-spindle pump (10) of single-flow design, having a pump housing (11) which has a pump section (12), a bearing section (13) and a gear-mechanism section (14) with a gear-mechanism chamber (21), wherein the bearing section (13) and the pump section (12) are separate from one another,

   - having a feeder-housing part as a constituent part of the pump section (12), in which two feeder screws (17, 18) which have flanks (46) and are arranged on shafts (15, 16) are provided, wherein the shafts (15, 16) are mounted in the bearing section (13) and extend into the gear-mechanism section (14),

   - having gearwheels (25, 26), which are arranged on the shafts (15, 16) in the gear-mechanism section (14) and by means of which the shafts (15, 16) are coupled for rotation,

   - having a fastening element (27), which is arranged on the shaft (16) in operative connection therewith, for establishing a retaining connection between the shaft (16) and the gearwheel (26), wherein the fastening element (27) and the gearwheel (26) have corresponding bores (36, 37) via which a retaining connection between the gearwheel (26) and the fastening element (27) can be established via a locking element, wherein the screw-spindle pump (10) can be mounted on a drive module (47), wherein the bores (36) in the fastening element (27) are designed such that the gearwheel (26) and the fastening element (27) can rotate with respect to one another, with the result that it is possible to adjust a distance between the flanks (46) of the feeder screws (17, 18), characterized in that an opening (42) is provided in the gear-mechanism section (14) of the pump housing (11), in that the opening (42) is provided with a detachable cover (43), in that the opening (42) is arranged such that the cover (43) can be detached when the screw-spindle pump (10) has been mounted on the drive module (47), in that, for the purpose of adjusting the backlash of the feeder screws (17, 18), the gear-mechanism chamber (21) can be reached by the requisite tool, and in that the bores (36) in the fastening element (27) are provided in the form of slots (41) in the circumferential direction with a centre line of constant radius, it being possible for the locking element to be displaced therein in the inserted but non-locked state, and in that the length of the slot (41) in the circumferential direction is such that the end points of the slot correspond at least with the points of contact of the flanks (46) of the feeder screws (17, 18) when the locking element is being displaced in the slot (41).
2. Spindle pump (10) according to Claim 1, characterized in that the fastening element (27) with the slots (41) is provided only on one shaft (16).
3. Pump (10) according to Claim 1 or 2, characterized in that the pump section (12) and the bearing section (13) are hydraulically separated, preferably by way of a mechanical seal, and/or in that the bearing section (13) and the gear-mechanism section (14) are spatially separated.
4. Pump (10) according to one of Claims 1 to 3, characterized in that the fastening element (27) has a bushing section (28) for pushing onto the shaft (16), wherein the bushing section (28) preferably has a receiving section for the gearwheel (26), and/or wherein the shaft (16) and the bushing section (28) have a groove for receiving a feather key for establishing a rotary operative connection between the shaft (16) and the fastening element (27).
5. Pump (10) according to one of Claims 1 to 4, characterized in that the bores (37) in the gearwheel (26) are in the form of drilled holes with a threaded section, and/or in that a locking element in the form of a screw, which makes it possible to establish the retaining connection, can be inserted into the bore (37).
6. Pump (10) according to one of Claims 1 to 5, characterized in that a bore into which a locking element which locks the fastening element (27) with respect to the shaft can be introduced is provided in the shaft head.

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