Pump arrangement for driving an impeller using an inner rotor which interacts with an outer rotor and the outer rotor having a radially outer circumferential projection

Abstract

A pump arrangement, in particular a magnetic coupling pump arrangement, includes a pump housing having an interior, a split case which hermetically seals a chamber surrounded by the split case from the interior formed by the pump housing, an impeller shaft with an impeller thereon which can be driven in a rotatable manner about a rotational axis, an inner rotor arranged at an end of the impeller shaft opposite the impeller end, an outer rotor which interacts with the inner rotor, and an adapter element which connects the split case to the pump housing or to a component paired with the pump housing, in particular a housing cover. The adapter element includes a mounting flange which rests against a support surface of the pump housing, in particular of the housing cover (4), on a face adjacent to the interior.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of PCT International Application No. PCT/EP2014/060197, filed May 19, 2014, which claims priority under 35 U.S.C. § 119 from German Patent Application No. 10 2013 008 795.3, filed May 24, 2013, the entire disclosures of which are herein expressly incorporated by reference.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a pump arrangement, in particular a magnetic clutch pump arrangement, having an interior space formed by a pump casing of the pump arrangement, having a containment can which hermetically seals off a chamber surrounded by said containment can with respect to the interior space formed by the pump casing, having an impeller shaft which can be driven in rotation about an axis of rotation, having an impeller which is arranged on one end of the impeller shaft, having an inner rotor arranged on the other end of the impeller shaft, and having an outer rotor which interacts with the inner rotor.

A pump arrangement of said type is known from German patent publication no. DE 10 2004 003 400 A1. In order to increase the range of use, this pump arrangement has a drive rotor formed as an identical part for outer drive elements. This however permits an increase in the range of use only to a particular degree. Above a certain structural size, an adaptation of the rotor size is unavoidable.

European patent publication no. EP 0 814 268 A1 has disclosed a modular construction kit for producing pumps, which modular construction kit is intended to afford the possibility of producing pumps in any desired manner from a small number of structural elements in accordance with the usage requirements. The proposed solution however permits only an exchange of components associated with a single structural size.

The documents cited above however do not take into consideration that, owing to different rotational speeds, delivery heights, delivery volumes and densities of the medium to be delivered, a large range of torques is required for a given hydraulic size.

It is an object of the invention to provide a magnetic clutch pump arrangement in which as large as possible a number of magnetic clutches with different diameters is available for one hydraulic size, and the greatest possible number of different hydraulic sizes can be used for one magnetic clutch size. It is likewise the intention for different containment cans, that is to say different pressure stages and/or materials, to be able to be used within one magnetic clutch size.

This object of the invention is achieved by an adapter element which connects the containment can to the pump casing or to a component assigned to the pump casing, in particular to a casing cover, the adapter element having a mounting flange which, at the side close to the interior space, bears against an abutment surface of the pump casing, in particular of the casing cover.

Through the use of different adapter elements, a modular construction kit is made available which permits efficient structural size configuration for one hydraulic size with different magnetic clutch sizes, or for one magnetic clutch size and different hydraulic sizes.

It is thus possible in a simple manner, by adaptation of the adapter element in terms of shape and/or size, to adapt a magnetic clutch size to different hydraulic sizes. The large range of torques required for the same hydraulic size owing to different rotational speeds, delivery heights, delivery volumes and densities of the medium to be delivered is covered in this way. It is no longer necessary to use the maximum clutch size for all combinations; rather, it is possible in each case for the suitable magnetic clutch size to be adapted to a hydraulic size, with corresponding advantages with regard to energy efficiency, eddy current losses and/or procurement costs. A further advantage of the invention is the reduced number of components that have to be stocked for a pump type series.

In a further refinement, the abutment surface has a region which is recessed in an axial direction and into which a centering ring formed on the mounting flange engages. It is firstly possible for a seal ring to be arranged in the recessed region, and secondly, the adapter element can be aligned exactly and fastened in fluid-tight fashion to the casing cover.

By virtue of the fact that, on the side situated opposite the mounting flange, the adapter element has multiple threaded holes for the fastening of the containment can, it is possible, within one magnetic clutch size, to use or interchange different containment cans of different pressure stages or strengths and/or different materials.

According to the invention, on the side situated opposite the mounting flange, a ring is provided which extends further in the axial direction into the interior space, which ring forms a run-on safeguard and prevents contact between the outer rotor and the containment can.

To improve the flow guidance of the medium, and for easier and thus cheaper production by casting, the outer contour of the adapter element has a substantially conical profile.

Here, the adapter element preferably narrows, substantially proceeding from the mounting flange toward the ring.

In a further refinement, it is provided that that end of the outer rotor which points in the direction of the casing cover has a radially encircling projection. In this way, the radial spacing of the outer rotor to the ring for normal operation can be produced in an exact manner.

For the same reason, alternatively or in addition, the projection may be formed on the inner side of the ring.

In a further exemplary embodiment of the invention, it is provided that the end of the outer rotor which points in the direction of the casing cover has a region of reduced outer diameter. The mounting capability of the adapter element in the case of small clutch diameters is thus ensured.

In a further advantageous refinement, between the impeller and inner rotor, there is arranged a bearing arrangement which is operatively connected to the impeller shaft, which can be driven rotatably about the axis of rotation.

In the context of the invention, it is proposed that, in a further embodiment, a spring device is arranged between the inner rotor and the bearing arrangement.

According to the invention, in one embodiment, between the spring device and the inner rotor, there is situated a spacer sleeve, which is pushed onto the impeller shaft and by means of which the inner rotor extends deeper into the outer rotor in an axial direction. Thus, the magnets of the inner rotor and the magnets of the outer rotor are optimally aligned with respect to one another in order to ensure an optimum transmission of power from the outer rotor to the inner rotor.

Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the longitudinal section through a magnetic clutch pump arrangement in accordance with an embodiment of the invention,

FIG. 2 shows the longitudinal section through the magnetic clutch pump arrangement as per FIG. 1 with an adapter element according to an embodiment of the invention,

FIG. 3 shows the longitudinal section through the magnetic clutch pump arrangement as per FIG. 1 with a further adapter element according to an embodiment of the invention,

FIG. 4 shows the longitudinal section through a magnetic clutch pump arrangement with a casing cover which serves as a heat barrier, and with an adapter element according to the invention in FIG. 2.

DETAILED DESCRIPTION

FIG. 1 shows a pump arrangement 1 in the form of a magnetic clutch pump arrangement. The pump arrangement 1 has a multi-part pump casing 2 of a centrifugal pump, which pump casing comprises a hydraulics casing 3 in the form of a spiral casing, a casing cover 4, a bearing carrier cage 5, a bearing carrier 6 and a bearing cover 7.

The hydraulics casing 3 has an inlet opening 8 for the intake of a delivery medium and has an outlet opening 9 for the discharge of the delivery medium. The casing cover 4 is arranged on that side of the hydraulics casing 3 which is situated opposite the inlet opening 8. The bearing carrier cage 5 is fastened to that side of the casing cover 4 which is averted from the hydraulics casing 3. The bearing carrier 6 is mounted on that side of the bearing carrier cage 5 which is situated opposite the casing cover 4. The bearing cover 7 in turn is fastened to that side of the bearing carrier 6 which is averted from the bearing carrier cage 5.

A containment can 10 is fastened to that side of the casing cover 4 which is averted from the hydraulics casing 3, and said containment can extends at least partially through an interior space 11 delimited by the pump casing 2, in particular by the casing cover 4, by the bearing carrier cage 5 and by the bearing carrier 6. The containment can 10 has a substantially cylindrical main body 12. The main body 12 is open on one side and is closed by way of a domed base 13 on the side situated opposite the open side. At the open side there is arranged a ring-shaped fastening flange 14 which is formed integrally with the main body 12 or which is connected to said main body by welding or by way of other suitable fastening means or devices, for example screws, rivets or the like. The fastening flange 14 bears, at the side close to the interior space 11, against an abutment surface 15 of the casing cover 4, and has multiple installation holes 16 through which screws 17 can be passed and screwed into threaded bores 18 provided in the casing cover 4. The containment can 10 hermetically seals off a chamber 19, which is enclosed by said containment can and by the casing cover 4, with respect to the interior space 11.

An impeller shaft 20 which is rotatable about an axis of rotation A extends from a flow chamber 21, which is delimited by the hydraulics casing 3 and by the casing cover 4, into the chamber 19 through an opening 22 provided in the casing cover 4. An impeller 23 is fastened to a shaft end, situated within the flow chamber 21, of the impeller shaft 20, and an inner rotor 24 arranged within the chamber 19 is provided on the opposite shaft end, which has two shaft sections 20a, 20b with increasing diameters in each case. The inner rotor 24 is equipped with multiple magnets 25 which are arranged on that side of the inner rotor 24 which faces toward the containment can 10.

Between the impeller 23 and the inner rotor 24 there is arranged a bearing arrangement 26 which is operatively connected to the impeller shaft 20, which can be driven in rotation about the axis of rotation A. A bearing ring carrier 27, which is arranged coaxially with respect to the axis of rotation A and by means of which the static parts, that is to say the parts which do not rotate with the impeller shaft 20, of the bearing arrangement 26 are held in place, bears by way of a flange-like region 28 against a further abutment surface 29 of the casing cover 4, is fastened by way of a screw connection (not illustrated) to the casing cover 4, and extends into the chamber 19.

Between the inner rotor 24 or the shaft section 20a and the bearing arrangement 26, in particular those parts of the bearing arrangement 26 which rotate with the impeller shaft 20, there is arranged a spring device 30 in the form of a plate spring pack, which spring device exerts a spring force on the clamped assembly composed of impeller 23, an impeller nut 32 which fastens the impeller 23 to the impeller shaft 20 via a disk 31, those parts of the bearing arrangement 26 which rotate with the impeller shaft 20, and the inner rotor 24, in such a way that the clamped assembly is held in abutment, in particular by way of the inner rotor 24, with a certain degree of elasticity against an abutment surface 33 which arises owing to the different diameters of the shaft sections 20a and 20b, wherein the diameter of the shaft section 20b is greater than the diameter of the shaft section 20a. The clamped assembly thus comprises substantially the components which rotate with the impeller shaft 20 about the axis of rotation A.

A drive motor, preferably an electric motor, which is not illustrated drives a drive shaft 34. The drive shaft 34, which can be driven about the axis of rotation A, is arranged substantially coaxially with respect to the impeller shaft 20. The drive shaft 34 extends through the bearing cover 7, through the bearing carrier 6, and at least partially into the bearing carrier cage 5. The drive shaft 34 is mounted in two ball bearings 35, 36 which are accommodated in the bearing carrier 6. On the free end of the drive shaft 34 there is arranged an outer rotor 38, which bears multiple magnets 37. The magnets 37 are arranged on that side of the outer rotor 38 which faces toward the containment can 10. The outer rotor 38 extends at least partially over the containment can 10 and interacts with the inner rotor 24 such that the rotating outer rotor 38, by way of magnetic forces, sets the inner rotor 24 and thus likewise the impeller shaft 20 and the impeller 23 in rotation.

FIG. 2 shows a pump arrangement 1, the outer dimensions of which correspond to the outer dimensions shown in FIG. 1. In accordance with a construction kit principle, the hydraulics casing 3, casing cover 4, bearing carrier cage 5, bearing carrier 6 and bearing 7 are thus of the same dimensions. Furthermore, in both embodiments, the impeller 23, bearing arrangement 26 and bearing ring carrier 27 are of the same dimensions. In the embodiment shown in FIG. 2, both the diameter and axial extent of containment can 10, inner rotor 24 and outer rotor 38 are smaller than in the embodiment shown in FIG. 1. This is particularly advantageous if lower power demands, for example a lower delivery height or delivery flow rate, with the highest possible efficiency, are placed on the pump arrangement 1.

To adapt the containment can 10 with reduced axial extent and reduced diameter, a separate adapter element 39 is provided which, on one side, has a mounting flange 40, the design of which substantially corresponds to the design of the fastening flange 14 of the containment can 10 as shown in FIG. 1. At the side close to the interior space 11, the mounting flange 40 bears against the abutment surface 15 of the casing cover 4 and has multiple installation holes 41, through which the screws 17 can be passed and screwed into threaded bores 18 provided in the casing cover 4. The abutment surface 15 has a region 42 which is recessed in an axial direction and in which a seal ring 43 is arranged and into which a centering ring 44 formed on the mounting flange 40 engages, whereby the adapter element 39 can be fastened in an exactly aligned and fluid-tight manner to the casing cover 4.

On the side situated opposite the mounting flange 40, the adapter element 39 has multiple threaded holes 45 into which there can be screwed screws 46 which extends through the installation holes 16 in the fastening flange 14 of the containment can 10. It is thereby possible, within a magnetic clutch size, to interchange different containment cans 10 of different pressure stages or strengths and/or different materials. Furthermore, on the side situated opposite the mounting flange 40, there is provided a ring 47 which extends further in an axial direction into the interior space 11, which ring forms a run-on safeguard and prevents contact between the magnets 37 of the outer rotor 38 and the main body 12 of the containment can 10. The outer contour of the adapter element 39 has in each case a substantially conical profile. Here, proceeding substantially from the mounting flange 40, the adapter element 39 narrows toward the ring 47. The inner contour of the adapter element 39 is at least partially of narrowing form. In the embodiment illustrated in FIG. 2, that end of the outer rotor 38 which points in the direction of the casing cover 4 has a radially encircling projection 48 facing toward the ring 47, which projection, in the possible case of an outer rotor 38 rotating with an imbalance, makes contact firstly with the inner side of the ring 47 of the adapter element 39 before the magnets 37 of the outer rotor 38 come into contact with the main body 12 of the containment can 10. In an alternative embodiment, the projection 48 may also be formed on the inner side of the ring 47. In a further embodiment, the projection 48 may be formed both on the end of the outer rotor 38 and on the inner side of the ring 47.

Between the spring device 30 and the inner rotor 24 there is situated a spacer sleeve 49 which is pushed onto the impeller shaft 20, and which expands the above-described clamped assembly by this component. In the embodiment shown, the impeller shaft 20, in particular shaft section 20a, is lengthened in relation to the embodiment shown in FIG. 1 by the length of the spacer sleeve 49. By means of the spacer sleeve 49, the inner rotor 24 extends deeper into the outer rotor 38 in the axial direction. In this way, the magnets 25 of the inner rotor 24 and the magnets 37 of the outer rotor 38 are optimally aligned with respect to one another in order to ensure an optimum transmission of power from the outer rotor 38 to the inner rotor 24.

FIG. 3 shows a pump arrangement 1, the outer dimensions of which correspond to the outer dimensions shown in FIGS. 1 and 2. Likewise, the impeller 23, bearing arrangement 26 and bearing ring carrier 27 are of the same dimensions as in the embodiment shown in FIGS. 1 and 2. In the embodiment shown in FIG. 3, both the diameter and the axial extent of the containment can 10, inner rotor 24 and outer rotor 38 have been reduced further in relation to the embodiment shown in FIG. 2. The impeller shaft 20, in particular shaft section 20a, has the same axial extent as in the embodiment shown in FIG. 2. That end of the outer rotor 38 which points in the direction of the casing cover 4 has a region 50, facing toward the ring 47, of reduced outer diameter, wherein an outer rotor 38, in the possible event of it rotating with an imbalance, comes into contact with the inner side of the ring 47 of the adapter element 39 by way of said region 50 first, before the magnets 37 of the outer rotor 38 come into contact with the main body 12 of the containment can 10.

As can be seen from FIG. 4, the adapter element 39 may also be used on a casing cover 4, formed as a heat barrier, in a pump arrangement 1 which conducts a hot medium. Here, the hydraulics casing 3, major regions of the casing cover 4, the bearing carrier cage 5, the bearing carrier 6 and the bearing cover 7 are of the same dimensions as in the exemplary embodiments shown in FIGS. 1 to 3. The containment can 10, the adapter element 39 and the outer rotor 38 are of the same dimensions, correspondingly to the magnetic clutch size as per FIG. 2.

The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.

LIST OF REFERENCE DESIGNATIONS

• 1 Pump arrangement
• 2 Pump casing
• 3 Hydraulics casing
• 4 Casing cover
• 5 Bearing carrier cage
• 6 Bearing carrier
• 7 Bearing cover
• 8 Inlet opening
• 9 Outlet opening
• 10 Containment can
• 11 Interior space
• 12 Main body
• 13 Base
• 14 Fastening flange
• 15 Abutment surface
• 16 Installation hole
• 17 Screw
• 18 Threaded bore
• 19 Chamber
• 20 Impeller shaft
• 20 a Shaft section
• 20 b Shaft section
• 21 Flow chamber
• 22 Opening
• 23 Impeller
• 24 Inner rotor
• 25 Magnet
• 26 Bearing arrangement
• 27 Bearing ring carrier
• 28 Flange-like region
• 29 Abutment surface
• 30 Spring device
• 31 Disk
• 32 Impeller nut
• 33 Abutment surface
• 34 Drive shaft
• 35 Ball bearing
• 36 Ball bearing
• 37 Magnet
• 38 Outer rotor
• 39 Adapter element
• 40 Mounting flange
• 41 Installation hole
• 42 Recessed region
• 43 Seal ring
• 44 Centering ring
• 45 Threaded hole
• 46 Screw
• 47 Ring
• 48 Projection
• 49 Spacer sleeve
• 50 Region of reduced outer diameter
• A Axis of rotation

Claims

1. A pump arrangement, comprising: a pump casing having an interior space;an impeller shaft arranged to be driven about an axis of rotation;an impeller arranged on a first end of the impeller shaft;an inner rotor arranged on a second end of the impeller shaft;an outer rotor which interacts with the inner rotor;a containment can arranged to hermetically seal off a chamber containing the inner rotor from a portion of the interior space containing the outer rotor; andan adapter element arranged to connect the containment can to at least one of the pump casing and a component connected to the pump casing,wherein the adapter element includes a mounting flange arranged to bear against an abutment surface of the at least one of the pump casing and the component connected to the pump casing in a region adjacent to the impeller,the adapter element includes a ring extending axially away from the mounting flange and concentrically surrounding at least a portion of the outer rotor, the ring being sized to radially guide the outer rotor to prevent contact between the outer rotor and the containment can, andan end of the outer rotor facing the pump casing includes a radially outer circumferential projection configured to make contact with a radially inner surface of the adapter element ring before magnets of the outer rotor contact the containment can.

2. The pump arrangement of claim 1, wherein the component connected to the pump casing is a casing cover.

3. The pump arrangement as claimed in claim 2, wherein the abutment surface has a region recessed in an axial direction configured to receive a centering ring of the mounting flange.

4. The pump arrangement as claimed in claim 3, wherein the adapter element includes a plurality of threaded holes on a side opposite the mounting flange.

5. The pump arrangement as claimed in claim 4, wherein the adapter element ring on the side opposite the mounting flange extends further away from the mounting flange than the plurality of threaded holes.

6. The pump arrangement as claimed in claim 5, wherein an outer contour of the adapter element has a circumference which tapers along the axis of rotation, decreasing in radius away from the casing cover.

7. The pump arrangement as claimed in claim 6, wherein the outer contour narrows from the mounting flange toward the ring in a curved manner in at least a portion of the outer contour.

8. The pump arrangement as claimed in claim 5, wherein a casing cover end of the outer rotor includes a region of reduced outer diameter.

9. The pump arrangement as claimed in claim 5, further comprising: a bearing arrangement arranged concentrically about the impeller shaft axially between the impeller and inner rotor.

10. The pump arrangement as claimed in claim 9, further comprising: a spring device is arranged concentrically about the impeller shaft axially between the inner rotor and the bearing arrangement.

11. The pump arrangement as claimed in claim 10, further comprising: a spacer sleeve arranged concentrically about the impeller shaft axially between the spring device and the inner rotor.

12. A modular construction kit, comprising: a pump casing having an interior space;an impeller shaft arranged to be driven about an axis of rotation;an impeller configured to be arranged on a first end of the impeller shaft;an inner rotor configured to be arranged on a second end of the impeller shaft;an outer rotor configured to interact with the inner rotor when the outer rotor and the inner rotor are in their respective installed positions;a containment can configured to be arranged in an installed position to hermetically seal off a chamber containing the inner rotor from a portion of the interior space containing the outer rotor; anda plurality of adapter elements, each configured to be arranged in an installed position to connect the containment can to at least one of the pump casing and a component connected to the pump casing,wherein each of the plurality of adapter elements includes a mounting flange configured such that when one of the plurality of adapter elements is in the installed position, the mounting flange bears against an abutment surface of the at least one of the pump casing and the component connected to the pump casing in a region adjacent to the impeller, anda ring extending axially away from the mounting flange and configured to concentrically surround at least a portion of the outer rotor, the ring being sized to radially guide the outer rotor to prevent contact between the outer rotor and the containment can, andwherein an end of the outer rotor facing the pump casing includes a radially outer circumferential projection at an end of the outer rotor facing the pump casing, the radially outer circumferential projection being configured to make contact with a radially inner surface of the adapter element ring before magnets of the outer rotor contact the containment can.

13. A pump arrangement, comprising: a pump casing having an interior space;an impeller shaft arranged to be driven about an axis of rotation;an impeller arranged on a first end of the impeller shaft;an inner rotor arranged on a second end of the impeller shaft;an outer rotor which interacts with the inner rotor;a containment can arranged to hermetically seal off a chamber containing the inner rotor from a portion of the interior space containing the outer rotor; andan adapter element arranged to connect the containment can to a component connected to the pump casing in the form of a casing cover,wherein the adapter element includes a mounting flange arranged to bear against an abutment surface of the casing cover in a region adjacent to the impeller, anda ring extending axially away from the mounting flange and concentrically surrounding at least a portion of the outer rotor, the ring being sized to radially guide the outer rotor to prevent contact between the outer rotor and the containment can, andwherein an end of the outer rotor facing the pump casing includes a radially outer circumferential projection at an end of the outer rotor facing the pump casing, the radially outer circumferential projection being configured to make contact with a radially inner surface of the adapter element ring before magnets of the outer rotor contact the containment can.