GB2289919A

GB2289919A - Submersible pump bearing arrangement

Info

Publication number: GB2289919A
Application number: GB9511154A
Authority: GB
Inventors: Bernhard Schleifer; Horst Krueger
Original assignee: Flux Geraete GmbH
Current assignee: Flux Geraete GmbH
Priority date: 1994-06-02
Filing date: 1995-06-02
Publication date: 1995-12-06
Anticipated expiration: 2015-06-02
Also published as: DE4419331C2; DE4419331A1; CH689949A5; FR2720789B1; GB2289919B; FR2720789A1; GB9511154D0

Description

1 2289919 PUMP, IN PARTICULAR A SUBMERSIBLE PUMP The invention relates to

a pump, in particular a submersible pump.

A known type of submersible pump comprises an outer pipe, an inner pipe within the outer pipe forming an annular channel between the pipes, and a pump shaft extending within the inner pipe and journalled by at least one bearing. The lower end of the pump shaft extends below the lower end of the inner pipe and carries a rotor fixed to the shaft, for ptunping a medium from a pump inlet through the annular channel, to an outlet provided on the outer pipe.

With these known pumps, the individual pump components cap be detached from one another only with great effort, so that cleaning of the pwnp components is possible only with difficulty. In particular, the bearings in the inner pipe which support the pump shaft can be removed from the inner pipe for cleaning purposes or for replacement only using a special tool. - Such pumps are therefore unsuitable in those cases where 100% cleanness of the pump components is necessary. Examples of such fields- of use are pharmaceuticals and the cosinetics and the foodstuffs and provisions sector.

The invention is based on the object of constructing a pwnp of the kind referred to such that the bearings supporting the pwnp shaft can easily be removed from the inner pipe.

According to the invention, there is provided a pump, in particular a submersible pump, having an outer pipe which, to form an annular channel, surrounds an inner pipe in which is rotatably journalled, by means of at least one bearing, a pump shaft which carries, on the lower end lying outside the inner pipe, a rotationally fixed rotor by which the medium to be pumped can be conveyed from a pump inlet via the 2 annular channel to an outlet provided on the outer pipe, characterized in that the bearing has at least one first positive locking component by which the bearing is positively connected axially with the inner pipe and which cooperates with at least one complementary further positive locking component of the inner pipe.

That is to say, the bearing is connected to the inner pipe in a manner such that the bearing cannot move axially relative to the inner pipe.

In a preferred arrangement the bearing is.positively located against axial movement relative to the inner pipe but can be readily separated from the inner pipe, for example by being radially withdrawn from the inner pipe.

In a particularly preferred arrangement, the positive locking components of or associated with the bearing on the one hand and the inner pipe on the other hand interact at respective abutment surfaces. facing in or substantially in the axial direction thereby providing restraint of the bearing against movement in the axial direction of the inner pipe.

In a particularly preferred arrangement the inner pipe and bearing interact substantially only by means of such abutment surfaces, so that the bearing is readily separable from the inner pipe.

In one preferred embodiment the inner pipe is provided with a transverse hole and the bearing is inserted in this hole in a substantially radial direction, so that it is positively located in the axial direction of the inner pipe but can be withdrawn radially from it. In another embodiment the inner pipe comprises axially adjacent segments and the bearing is located at the junction of these segments and is retained by at least one of 2 3 them against axial movement. The segments can be axially separated to enable the bearing to be removed.

In the pump according to the invention, the bearing is provided with the said positive locking component which cooperates with the corresponding complementary positive locking component of the inner pipe. The bearing is positively connected axially with the inner pipe via the positive locking component. Because of the positive locking connection, the bearing can be removed easily from the miner pipe in order to clean the bearing, the inner pipe, the outer pipe and the pump shaft. Because of the easy dismantling of these pwnp components, the pump according to the invention is outstandingly suitable in particular for use in the pharmaceutical, cosmetics, and the foodstuffs and provisions fields.

The invention is explained in more detail with the aid of embodiment examples shown in the accompanying drawings in which:

Fig. 1 shows a pump according to the invention, in axial section, Fig. 2 shows an outer pipe, in axial section, of the pump according to Fig. l., Fig. 3 shows an inner pipe, in axial section, of the pump according to Fig. 1, Fig. 4 shows a connecting component in axial section, of the pump according to Fig.

1, Fig. 5 is a plan view in the direction of arrow V in Fig. 4, Fig. 6 is an end view of a bearing for a pump shaft of the pump according to Fig. 1, Fig. 7 is a plan view in the direction of arrow VII in Fig. 6, Fig. 8 is a side view of a lower bearing piece of the pump according to Fig. 1, Fig. 9 is an underneath view of the bearing piece according to Fig. 8, Fig. 10 shows the bearing piece according to Fig. 8 in axial section, 3 4 Fig. 11 is a plan view of the bearing piece according to Fig. 8, Fig. 12 shows a foot piece, in axial section, of the pump according to Fig. 1, Fig. 13 shows a second embodiment, in axial section, of a pwnp according to the invention, Fig. 14 is a plan view of a bearing of the pump according to Fig. 13, Fig. 15 is a side view, partly in section, of the bearing according to Fig. 14, Fig. 16 is an end view of the bearing according to Fig. 14, Fig. 17 shows a further embodiment, in axial section, of a bearing of the pump according to the invention, Fig. 18 shows a further embodiment, in axial section, of a bearing of the pump according to the invention, Fig. 19 is a plan view of a further embodiment of a bearing of ihe pump according to the invention, and Fig. 20 shows the bearing according to Fig. 19 in axial section.

The pump according to Fig. 1 to 12 is employed in particular in the fields of pharmacy, cosmetics and foodstuffs. All the. components of the pump which come into contact with the particular liquid to be pumped are made of suitable plastic, preferably of polytetrafluoroethylene, of ceramic material or of stainless steel. The pump components can easily be dismantled for problem-free cleaning of the pump. Assembly of the pump is also correspondingly simple, which means that easy replacement of wearing components is also ensured.

The pump has an outer pipe 1 which surrounds an inner pipe 2 with a radial separation. A pump shaft 3 which carries a drive coupling component 4 fixed on the upper end and a rotor 5 fixed on the lower end is rotatablyjoumalled in this inner pipe. The coupling component 4 is coupled in a known manner with a coupling 4 component of a drive motor (not shown) in order to drive the pump shaft 3 in rotation. A union nut 6 with which the pump can be connected with the drive motor sits rotatably on the outer pipe 1.

The outer pipe 1 and the inner pipe 2 define between them an annular channel 7 in which the liquid to be pumped is conveyed from a pump inlet 8 at the lower end to an outlet 9 provided on the outer pipe 1.

A foot piece 10 which contains the pump inlet 8 and surrounds the rotor 5 is screwed onto the lower end of the outer pipe 1. A lower bearing piece 11 by which the pump shaft 3 is journalled directly above the rotor 5 is inserted.into the lower end of the outer pipe 1. In the region between the bearing piece 11 and the outlet 9, the pump shaft 3 is supported rotatably by bearings 12 distributed over the length of the inner pipe 2.

At the upper end of the inner pipe 2 is attached, preferably welded, a bush-like housing 13 which accommodates a connecting component 14, in which seals 15 which seal off the pump shaft 3 and bearings 16, preferably roller bearings, for the pump shaft 3, arranged one on top of another with an axial separation, are accommodated. The upper end of the pump shaft 3 projects into the connecting component 14. The coupling component 4 also lies within the connecting component 14. The outer pipe 1 (Fig. 2) has a constant internal and external diameter over its length and carries the coupling sleeve 6 at the upper end. This carries a thread 6' on the inside, with which the coupling sleeve 6 is screwed onto a corresponding connecting piece of the drive motor. On the outside, the coupling sleeve 6 is advantageously provided with a profile to facilitate screwing of the coupling sleeve onto the connecting piece of the drive 6 motor. At the end on the outer pipe side, the coupling sleeve 6 has a flange 17 directed radially inwards, with which, in the coupling position, it lies against a flange 10 directed radially outwards on the upper end of the outer pipe 1. So that the coupling sleeve 6 cannot be pulled off from the outer pipe 1, a securing component 19, preferably a Seeger circlip ring, is provided in the flange 18.

At the lower end, the outer pipe 1 is provided with a thread 20 on its outside, onto which the foot piece 10 is screwed. The foot piece 10 can also be screwed into the outer pipe 1. It is also possible to push the foot piece 10 onto or into the outer pipe 1 and to secure it in a suitable manner.

The inner pipe 2 (Fig. 3) has virtually the same internal and exiernal diameter over its entire length. At the upper end of the inner pipe 2 is provided the housing 13, which is preferably welded flush with the inner pipe 2. It has a cylindrical connecting piece 21 which has the same internal and external diameter as the inner pipe 2. The connecting piece 21 is joined to a cylindrical intermediate piece 22 of increased internal and external diameter. As Fig. 1 shows, a supporting and sealing ring 24 on which the seals 15 are supported lies on the annular shoulder running radially between the connecting piece 21 and the intermediate piece 22.

The intermediate piece 22 is joined by way of a flange 25 directed radially outwards, to a cylindrical end piece 26 which has a g.reater internal and external diameter than the intermediate piece 22. The end piece 26 has, close to its free front end, a surrounding flange 27 directed radially outwards, with which the housing 13 is supported on the inner wall of the outer pipe 1 at the level of the flange 18 (Fig. 1 and 2). The inner pipe 2 is thereby aligned perfectly with respect to the outer pipe 1 in the upper end region.

6 7 The inner pipe 2 has push-fit openings 28 and 29 spaced from one another. In each case two push-fit openings 28 or 29 lie diametrically opposite one another. The openings 28 have an angular offset from openings 29, which in the embodiment shown is 90% but can also have any other suitable angular separation. The axes 30 and 31 of the push-fit openings 28 and 29 are thus at an angle, preferably perpendicular, to one another. However, the push-fit openings can also be so provided that their axes lie parallel to one another. Further push-fit openings can also be provided, depending on the length of the.inner pipe 2.

At the lower end, the inner pipe 2 has a wall section 32,_ the wall thickness of which is reduced so that a circumferential shoulder 33 is formed in the 6uter wall of the inner pipe 2.

The connecting piece 14 (Fig. 1, 4 and 5) is a screw which is screwed with an end part 34 into the intermediate piece 22 of the housing 13 of the inner pipe 2. The intermediate piece 22 is provided with a corresponding internal thread 35 (Fig. 3), into 1 which an external thread 36 of the end part 34 is screwed. The end part 34 is long enough to abut on the supporting or sealing ring 24 in the assembled position (Fig. 1).

The end part 34 is joined, via an annular shoulder 3 7 directed radially outwards, a to cylindrical central component 3 8, which in turn is joined, via an annular shoulder 3 9 directed radially outwards, to a joining piece 40. The end part 34 accommodates the seal(s) 15 (Fig. 1), while the two bearings 16 are arranged in the central component 38 with a spacer bushing 41 as an intermediate layer (Fig. 1).

7 8 The joining piece 40 is cylindrical on the outside. Two plane lands 42 are provided diametrically opposite one another on the inside, of which one is shown in Fig. 5 and the other is shown in Fig. 4. They extend over the entire height of the joining piece 40.

At the transition from the central component 3 8 to the joining piece 40, the connecting component 14 is provided with a radial annular flange 43 which projects radially from the joining piece 40. As Fig. 1 -shows, the connecting component 14 lies with the under-side 44 (Fig. 4) of the annular flange 43 on the flange 18 of the outer pipe 1 in the installed position.

The flange under-side 44 is bounded radially on the inside by a cylinder surface 45, with which the connecting component 14 lies against the inside of the flange 18 of the outer pipe 1 (Fig. 1).

The central component 38 of the connecting component 14 lies with its outer wall against the inner wall of the end piece 26 of the housing 13 of the inner pipe 2 (Fig. 1). The cylinder surface 45 of the connecting component 14 is adjacent to an annular surface 46 running radially inwards, which in turn meets at right angles the outside of the central component 38 (Fig. 4). In the installed position, a ring seal 47 (Fig. 1) is inserted between the flange 27 of the housing 13 of the inner pipe 2 and the annular surface 46. It seals the outer pipe 1 from the connecting component 14 and the housing 13 of the inner pipe 2. Since the flange 27 of the housing 13 (Fig. 3) is spaced from the free of the housing 13, the seal 47 can easily be pushed onto the end piece 26 of the housing 13. The seal 47 therefore cannot be damaged or deformed unacceptably.

8 9 In a modification the connecting component 14 can be constructed as a push-fit component which is pushed into the housing 13 of the inner pipe 2 and secured in a suitable manner.

The bearing 12 with which the pump shaft 3 is rotatably supported inside the inner pipe 2 is explained in more detail with the aid of Fig. 6 and 7. The bearing 12 has a cylindrical push-fit component 48, the external diameter of which corresponds to the diameter of the push-fit openings 28, 29 of the inner pipe 2. So that the bearing 12 can be pushed easily into the push-fit openings 28, 29, the free end of the push-fit component 48 has converging flat surfaces 49 and 50 which are joined to one another via a flat end face 52 lying perpendicular to the axis 5 1 of.the push- fit component 48.

The push-fit component 48 extends perpendicularly from a bulfer component 53 which projects from the push-fit component 48 on both sides (Fig. 6). The width of the buffer component 53 corresponds to the external diameter of the push-fit component 48. The inner side 54 of the buffer component 53 facing the push-fit component 48 is curved over its width (Fig. 7). The radius of curvature is such that in the installed position, the buffer component 53 lies with this inner side 54 against the surface of the outer wall of the inner pipe 2. In the installed position, the bearing 12 is thus secured against twisting. Since the external radius of the inner pipe 2 and the radius of curvature of the inner side 54 of the buffer component 54 are the same, the bearing 12 cannot rotate around the axis 51 of the push-fit component 48 in the installed position.

The inner side 54 of the buffer component 53 extends essentially perpendicularly to the axis 51 of the push-fit component 48. The axis of curvature 55 of the inner side 9 54 forms the axis of a bearing opening 56, through which the pump shaft 3 passes. The axis 55 lies perpendicular to the axis 51 of the push-fit component 48.

The buffer component 53 has flat outer sides 57 and 58 parallel to one another, adjacent to which are flat slanted surfaces 59 and 60 which converge with one another and are connected to one another by a curved end face 61. All the outer sides 57 to 61 extend over the entire height of the buffer component 53.

To assemble the bearings 12, it is merely necessary to push them through the push-fit openings 28, 29 of the inner pipe 2 until the buffer component 53 lies against the surface of the outside of the inner pipe 2. As a result of the curved inner side 54 of the bulfer component 53, the bearing opening 56 which passes'diametrically through the push-fit component 48 is thereby also simultaneously aligned axially with respect to the inner pipe 2. It is then merely necessary to push in the pwnp shaft 3 from the upper end of the inner pipe 2. Since the bearing openings 56 of the bearing 12 are aligned in the manner described, the pump shaft 3 can be pushed in ellortlessly.

The inner pipe 2 and bearings thus pre-assembled is then pushed into the outer pipe. The bearings 12 are long enough for the end faces 52 and 61 of the bearings, which are curved according to the internal radius of the outer pipe 1, to lie against the surface of the inner wall of the outer pipe 1 (Fig. 1). Not only is the pump shaft 3 thus rotatably supported by the bearings 12, but at the same time the inner pipe 2 is also aligned with respect to the outer pipe 1. The radius of the bearing openings 56 corresponds to the radius of the pump shaft 3, which is thus guided perfectly over its length. Since the push-fit openings 28, 29 of the inner pipe 2 are each displaced by 11 90' with respect to one another, the bearings 12 which follow one another with a separation are each at right angles to one another. Optimum alignment and support of the inner pipe 2 within the outer pipe 1 is thereby ensured.

Alternatively the push-fit component 48 of the bearing 12 can have a noncircular cross-section. The push-fit openings 28, 29 of the inner pipe 2 then have a corresponding outline shape. Securing of the bearings 12 against twisting with respect to the inner pipe 2 can thereby be achieved very easily.

In the lower end region, the pump shaft 3 is rotatably supported by the bearing piece 11, which is to be described in more detail with the aid of Fig. 8 to 11. The bearing piece 11 is advantageously constructed in one piece from a suitable plastic, preferably from polytetrafluoroethylene. It can also be made of other bearing materials, such as ceramic, carbon, metals and the like. The bearing piece 11 has a ring component 62, the external diameter of which corresponds to the internal diameter of the outer pipe 1. In the installed position, the bearing piece 11 lies with this ring component 62 against the inner wall of the outer pipe 1 (Fig. 1). The ring component 62 has a diametrical intermediate piece 63 which stiffens the thin-walled ring component 62. At half the length, the intermediate piece 63 is widened to form a bearing bush 64 (Fig. 9). The puinp shaft 3 is rotatabe in this at the lower end (Fig. 1). The inner waH 65 of the ring component 62 runs radially inwards with a curvature, in the region of the intermediate piece 63, which means that the ring component 62 is widened in the connecting regions 66, 67 to the intermediate piece 63. The bearing bush 64 extends over the axial length of the ring component 62 (Fig. 10).

At the level of the upper front face rim 68 of the ring component 62, the intermediate piece 63 continues in a cross piece 69, which has essentially the same outline as the 11 12 intermediate piece 63, but is wider than this (Fig. g). At half the width, the cross piece 69 has a cylindrical component 70, the external diameter of which is greater than the width 71 of the cross piece 69 (Fig. 11). The width 71 of the cross piece 69 is smaller than the internal diameter of the ring component 62. Flow chambers 72 and 73 for the medium to be pumped, which are connected in flow with the annular channel 7, thereby remain on both sides of the cross piece 69 and therefore also of the intermediate piece 63. The cylindrical component 70 projects axially relative to the cross piece 69 (Fig. 8 and 10)..

An opening 74 which crosses the bearing opening 75 of the bearing bush 64 and the cylindrical component 70 passes through the cross piece 69 in its longitudinal direction. As Fig. 8 shows, the opening 74 extends in the axial direction of the cross piece 69 at half the width thereof.

At about the level of the upper edge of the opening 74, the inner wall 76 (Fig. 10) of the cylindrical component 70 is joined to an annular shoulder surface 77 directed radially inwards, which in turn is joined to apylindrical inner wall 78 of reduced internal diameter.

The opening 74 passes radially through this. Offset at about the level of the lower edge of the opening 74, the inner wall 78 merges into the inner wall of the bearing opening 75. The intermediate piece 63 projects slightly past the ring component 62 at the end opposite the cross piece 69 (Fig. 8). At this end, the intermediate piece extends radially from the outside of the.ring component 62. Two lugs 79, 80 diametrically opposite one another are thereby formed (Fig. 10) and, in the installed position, project into corresponding openings 81 and 82 (Fig. 2) of the outer pipe 1. The openings are open in the direction of the lower end of the outer pipe 1. When the 12 bearing piece 11 is pushed into the lower end of the outer pipe 1, the lugs 79, 80 thereby enter the openings 81, 82. The lugs 79, 80 and the associated openings 81, 82 serve to align the opening 74 of the bearing piece 11 with respect to openings 83 (Fig. 2) diametrically opposite one another in the outer pipe 1 and to keep the bearing piece secure against twisting on the outer pipe 1.

As can be seen from Fig. 1, the bearing piece 11 lies against the inner wall of the outer pipe 1. The lower end 32 of the inner pipe 2 projects into the cylindrical component 70, and the inner pipe is thereby guided perfectly radially in this end region. The lugs 79, 80 are only wide enough for their front faces to lie flush with the outside of the outer pipe 1. The foot piece 10 can thereby be screwed-onto the lower end of the outer pipe without problems.

The end faces 84, 85 (Fig. 11) of the cross piece 69 are curved so that they lie against the surface of the inner wall of the outer pipe 1 and provide a seal.

The foot piece 10 (Fig. 12) has a screw component 86 of increased internal and external diameter, which is provided with an internal thread 87. The foot piece 10 is screwed with the screw component 86 onto the lower end of the outer pipe 1. The rotor 5, which is screwed onto the end of the pump shaft 3 projecting into the foot piece, is accommodated within the foot piece 10 in a known manner. At the lower edge, the foot piece 10 is provided with tmo open-edged entry openings 88 diametrically opposite one another, which form the pump inlet. Short bars 89, 90 radially opposite one another project perpendicularly radially inwards at the level of the ends facing away from one another of the two entry openings 88. These bars 89, 90 reliably prevent the formation of bubbles during suction of the liquid to be pumped.

13 14 The pump described can be assembled and in particular also dismantled very easily, so that the individual pump components can be cleaned without problems. Because of the easy dismantling, 100% cleanness or sterilization of the pump components, for example by irradiation, dry heat, gas treatment or chemical treatment, is possible.

To assemble the punip, the sealing ring 47 is first pushed onto the housing 13 until it lies against the flange 27. The supporting or sealing ring 24 is inserted into the housing 13. The connecting component 14, into which the seals 15 have first been inserted, is then screwed into the housing 13. The bearings 12 can then be pushed into the inner pipe 2 through the push-fit openings 28, 29. As a result of the buffer component 53, the bearings 12 can easily be so aligned that the bearing openings 56 lie on the axis of the inner pipe 2. The pump shaft can then be pushed in easily from the connecting component 14. The roller bearings 16, the spacer bush 41 and the coupling component 4 are already pre-assembled on the puinp shaft 3. This structural unit is then pushed into the outer pipe 1.. The bearing piece 11 can already be pushed into the outer pipe 1. However, it is also possible to push in the bearing piece 11 after the inner pipe 2 has been pushed in. The lower end of the pump shaft 3 projects past the bearing piece 11 so that the rotor 5 can now easily be screwed on. Finally, the foot piece 10 is screwed onto the outer pipe 1. This assembly can also be carried out effortlessly by less experienced persons. Dismantling of the pump is also correspondingly simple.

The pump is constructed without seals. The medium sucked in by the rotor 5 passes through the flow chambers 72, 73 of the bearing piece 11 into the annular channel 7, in which the medium is pumped up to the outlet 9. If the medium is to pass upwards between the pump shaft 3 and the bearing bush 64 of the bearing piece 11, the medium passes into the opening 74 of the bearing piece. Since this is connected with the 1 4 openings 81, 82 of the outer pipe 1, the liquid which has risen can flow outwards. Since the opening 74 is provided within the crosspiece 69, there is no connection to the flow chambers 72, 73 The puinp according to Fig. 13 to 16 is essentially of the same construction as the previous example. Only the shaft bearings 12a have a different construction. The bearing 12a has a push-fit component 48a, which has a non-circular outline, in the embodiment example approximately rectangular. Securing of the bearing 12a against twisting with respect to the inner pipe 2 is thus already achieved by the push-fit component 48a. The push-fit component 48a is tapered at both ends, so that it can be pushed without effort into the push-fit openings 28a, 29a-of the inner pipe 2.

At one end of the push-fit component 48a is provided the buffer component 53a, which has a rectangular cross-section and extends away from one end of the push-fit component 48a. The bearing opening 5,6a for the pump shaft 3 passes through the push-fit component 48a. The buffer component 53a is long enough to lie with its end faces 91 and 92 against the inner wall of the puter pipe 1 and against the outer wall of the inner pipe 2 in the installed position. As Fig. 13 shows, the push-fit component 48a furthermore lies with its end surface 52a against the inner wall of the outer pipe 1. With this bearing component, the pump shaft 3 is thus also aligned with respect to the inner pipe 2 and the inner pipe is aligned with respect to the outer pipe 1 Fig. 17 to 20 show further embodiments of bearings for rotatably supporting the pump shaft.

The bearing 12b according to Fig. 17 is cylindrical and has, at half the length, a circumferential flange 93 directed radially outwards, the external diameter of which 16 corresponds to the external diameter of the inner pipe 2. The inner pipe 2 comprises individual pipe pieces 94, 95, which are pushed or screwed onto the bearing 12b. With its outside, the flange 93 forms a flush continuation of the outside of the pipe pieces 94, 95. The pipe pieces 94, 95 lie with their ends tightly against the bearing piece 12b. Several pipe pieces and several bearings which can be joined to one another by push-fit connections in the manner described are provided, depending on the length of the inner pipe 2. Such a construction also ensures easy assembly and dismantling of the pump.

In the embodiment according to Fig. 18, the pipe pieces 94c, 95c of the inner pipe 2 are screwed directly to one another. The bearing 12c has.a flange 93c, against which the pipe pieces 94c, 95c lie with their lateral shoulder surfaces 96, 97. The bearing 12c is covered completely on the outside by the pipe pieces 94c, 95c. The pipe pieces can be screwed to one another, or can be merely pushed together. In both cases, the pump can be assembled and dismantled easily.

The bearing 12d, according to Fig. 19 and 20. is star-shaped in construction. It has a cylindrical central component 98 which has, at half the axial length, a central piece 99 containing the bearing opening 56d. Four bores 100 which are distributed uniformly around the bearing opening 56d. with a small radial separation pass axially through it in the example shown. Three arms 101 which have the same radial length and the same axial length

as the central component 98 extend radially away from the central component 98. The end faces 102 of the arms 10 1, which have the same angular separation from one another, lie on an imaginary cylindrical envelope, the radius of which corresponds to the internal radius of the outer pipe 1. These bearings 12d of star-shaped construction 16 i 17 thereby lie with the end faces 102 of their arms 10 1 against the surface of the inner wall of the outer pipe 1.

The bores 100 form leakage openings, through which liquid which has risen above the bearings within the inner pipe can flow down again. Such bores are also provided in the bearings according to Fig. 17 and 18.

The central piece 99 of the bearing 12d forms a positive locking component which cooperates with the end faces 103, 104 of the pipe pieces 94d, 95d of the inner pipe 2. The pipe pieces 94d, 95d are pushed into the central component 98 of the bearing 12d and lie with their outer surfaces against the inner wall of the central component 98 (Fig. 20). The inner pipe 2d can thus easily be assembled and dismantled by pushing together the pipe pieces 94d, 95d and the corresponding number of bearings 12d. The bores 100 are so provided that they he within the pipe pieces 94d, 95d, when viewed in the axial direction thereof. The bearings 12d also have a double function in this embodiment. On the one hand they serve to journal the pump shaft 3, and on the other hand they align the inner pipe 2 with respect.to the outer pipe 1.

The bearing 12b can also fulfil this double function in the embodiment according to Fig. 17 if the flange 93 is enlarged radially so that it lies against the inner wall of the outer pipe 1.

17 18

Claims

Claims

1. A pump, in particular a submersible pump, having an outer pipe which, to form an annular channel, surrounds an inner pipe in which is rotatablyjournalled, by means of at least one bearing, a pump shaft which carries, on the lower end lying outside the inner pipe, a rotationally fixed rotor by which the medium to be pumped can be conveyed from a pwnp inlet via the annular channel to an outlet provided on the outer pipe, characterized in that the bearing has at least one first positive locking component by which the bearing is positively connected axially with the inner pipe and which cooperates with at least one complementary further positive locking compone nt. of the inner pipe.

2. A pump according to Claim 1, characterized in that the first positive locking component is a push-fit component which passes radially through the inner pipe.

3. A pwnp according to Claim 1 or 2, characterized in that the inner pipe contains push-fit openings for the first positive locking component which constitute the further positive locking components.

A pump according to Claim 1, characterized in that the first positive locking component is a flange which extends radially away from the bearing, which preferably extends axially within the inner pipe- 5.

A pump according to Claim 4, characterized in that the inner pipe comprises at least two pipe pieces which lie, with their end regions which face one another, against the two sides of the flange.

18 19 6. A pump according to Claim 4 or 5, characterized in that the outside of the flange of the bearing lies in the outer wall of the inner pipe.

7. A Pump according to any one of Claims 4 to 6, characterized in that the bearing has arms extending radially outwards which lie against the inner wall of the outer pipe and preferably extend radially away from a cylindrical central component into which the pipe pieces of the inner pipe are preferably pushed.

8. A pump according to Claim 7, characterized in that the flange of the bearing is provided in the central component and contains a bearing opening for the pump shaft.

9. A pump according to Claim 2 or 3, characterized in that a bearing opening passes through the first positive locking component.

10. A purnp according to Claim 2, 3 or 9, ' characterized in that the first positive locking component is provided with at least one buffer component which lies against the outer wall of the inner pipe, preferably also against the inner wall of the outer pipe.

11. A pump according to Claim 10, characterized in that the contact side of the buffer component is curved according to the external radius of the inner pipe and/or the internal radius of the outer pipe.

12. A purnp according to any one of Claims 2, 3, 9, 10 or 11, characterized in that the push-in end of the first positive locking component is tapered.

19 13. A pump according to any one of Claims 1 to 12, characterized in that the inner pipe has on its upper end a housing-like receiver for a connecting component which can preferably be screwed into the receiver, by which the pwnp can be connected to a drive motor and which preferably accommodates at least one seal and at least one bearing, preferably a roller bearing, for the pump shaft.

14. A pump according to one of Claims 1 to 13, characterized in that a foot piece which contains the pump inlet can be screwed onto the lower end of the outer pipe.

15. A pump according to any one of Claims 1 to 14, characierized in that a bearing piece for the pump shaft, which preferably has at least one opening which is separate from the annular channel and is connected with at least one exit opening in the outer pipe, can be pushed into the lower end of the outer pipe.

16. A ptunp according to Claim 15, characterized in that the inner pipe is pushed with its lower end into a receiver component of the bearing piece.

17. A pump according to Claim 15 or 16, characterized in that the rotor is screwed onto the end of the pump shaft projecting downwards beyond the bearing piece.

18. A pump according to Claim 1 in which the said positive locking components are provided with respective abutment surfaces extending transversly relative to the axial direction of the inner pipe, at which they interact thereby axially locating the bearing relative to the inner pipe.

1 21 19. A pump according to any of the preceding claims in which the said positive locking components provide positive location of the bearing against movement in the axial direction of the inner pipe while permitting the bearing to be readily separated from the inner pipe.

20. A submersible pump substantially as herein described with reference to Figures 1 to 12, Figures 13 to 16, Figure 17, Figure 18 or Figures 19 and 20 of the accompanying drawings.

21