DE102013107986A1 - circulating pump - Google Patents

Abstract

The invention relates to a circulating pump, comprising a conveying element for conveying a conveying fluid and an electric motor having a stator and a rotor, between which a gap is formed, wherein the rotor comprises a shaft rotatable about a rotation axis, with which the conveying element is rotatably connected , and wherein the circulation pump has a radial sliding bearing for supporting the shaft, which is liquid lubricated at a lubrication region with the conveying liquid. In order to provide such a circulation pump, with which a more reliable operation is made possible, it is proposed according to the invention that the circulating pump comprises a sealing device which prevents a fluid connection between the lubrication region and the gap between the stator and the rotor.

Description

The invention relates to a circulating pump, comprising a conveying element for conveying a conveying fluid and an electric motor having a stator and a rotor, between which a gap is formed, wherein the rotor comprises a shaft rotatable about a rotation axis, with which the conveying element is rotatably connected , and wherein the circulation pump has a radial sliding bearing for supporting the shaft, which is liquid lubricated at a lubrication region with the conveying liquid.

Such a circulating pump is used for example in heating systems, wherein it may be in the funded liquid in particular water. The delivery fluid is conveyed by means of the conveying element, for example a delivery wheel, which is non-rotatably connected to the shaft. The shaft is radially mounted with respect to the axis of rotation by means of a sliding bearing, which for example comprises bearing elements made of graphite, whereby a compact construction of the circulating pump can be achieved. To reduce wear and heat dissipation, the sliding bearing is fluid lubricated, wherein the lubrication to achieve a constructive simplification of the circulation pump is carried out by the pumped liquid.

Conventional circulation pumps have to drive the electric motor, in which the rotor comprising the shaft is rotatable about the axis of rotation relative to the stator. The rotor usually moves, as in asynchronous motors, free of contact with the stator, for which purpose a gap between the rotor and the stator is formed. The gap is penetrated by the magnetic fields generated by the stator for driving the rotor and may be filled with liquid, in particular with the delivery liquid. For this purpose, there are generic circulating pumps in which the lubrication region is in fluid communication with the gap. It is desirable for a high efficiency of the circulation pump to form the gap between stator and rotor as narrow as possible.

Object of the present invention is to provide a circulating pump of the type mentioned, with a more reliable operation is made possible.

This object is achieved in a generic circulation pump according to the invention in that the circulation pump comprises a sealing device which prevents fluid communication between the lubrication region and the gap between the stator and the rotor.

In the circulation pump according to the invention a targeted lubrication of the sliding bearing can be ensured at the lubrication area with the pumped liquid. This makes it possible to effectively reduce wear of the sliding bearing and dissipate frictional heat between the sliding bearing and the shaft via the conveying liquid. In addition, a sealing device is provided in the circulation pump according to the invention, with which a fluid connection between the lubrication region and the gap between the stator and the rotor can be prevented or at least largely prevented. This makes it possible to prevent a fluid flow with the pumped liquid from forming between the lubrication region and the gap between the stator and the rotor. The amount of pumped liquid passing through the gap can thereby be reduced. This proves to be particularly advantageous in electric motors, which have a narrow gap to achieve high efficiency and also work with strong alternating magnetic fields. These include in particular electrically commutated electric motors, so that in particular a circulation pump according to the invention can be operated with electrically commutated electric motor by the teaching of the invention more reliable. In particular, in the presence of even narrow gaps between the stator and rotor by reducing the volume flow of fluid through the gap reduces the likelihood that in the fluid conveyed magnetic particles stuck to the rotor or stator. Such accumulation of magnetic particles results in undesirable friction between the rotor and the stator. The friction can lead to a drop in efficiency, to the development of noise and heat, to undesirable wear and even to the failure of the circulation pump. These disadvantages, which are due to the accumulation of magnetic particles in the gap between the stator and rotor, can thus be largely avoided in the circulation pump according to the invention.

It is advantageous if the circulation pump comprises a fluid guide which has at least one fluid channel through which fluid can flow for supplying, passing or discharging delivery fluid into, through or out of the lubrication region. This makes it possible in a structurally simple manner to provide a flow of pumped liquid at the lubrication area.

In a simple way, the fluid guide can be realized by bypassing the gap between the stator and the rotor.

The fluid guide is, for example, guided past the gap between the stator and the rotor.

Preferably, at least one inlet opening for delivery fluid is provided in a fluid channel and at least one outlet opening for delivery fluid from a fluid channel. It can be provided, for example, that at least one fluid channel is in fluid communication via an inlet opening or via an outlet opening with a delivery chamber of the circulating pump, in which the delivery element is arranged.

It is expediently provided that a fluid channel is fluid-connected via at least one inlet opening to a pressure side or suction side of the circulating pump and / or that a fluid channel is fluid-connected via at least one outlet opening to a pressure side or suction side of the circulating pump.

Advantageously, at least one fluid channel for the delivery liquid is arranged at the lubrication region, and / or the circulation pump preferably comprises a fluid conduit having at least one fluid channel for delivery fluid.

A compact construction of the circulation pump can be achieved if at least one fluid channel is formed in the plain bearing or in the shaft. This makes it possible to save separate fluid channels, so that a structurally simple embodiment of the circulating pump can be achieved. It can be provided that in each case a plurality of fluid channels is formed in the sliding bearing and / or in the shaft.

It is also conceivable that at least one fluid channel is formed on the sliding bearing or on the shaft.

An arranged between the sliding bearing and the shaft bearing gap can form a fluid channel.

In a structurally simple embodiment of the circulation pump, it is favorable if at least one fluid channel is arranged between the sliding bearing and the shaft. For example, a recess may be arranged on the side of the sliding bearing facing the shaft, for example a groove-shaped recess, for forming a fluid channel between the shaft and the slide bearing. Through the recess through the conveying liquid can be performed to wet both the shaft and the plain bearing and provide an efficient fluid lubrication.

It is advantageous if at least one inlet opening or outlet opening is formed on the shaft through which delivery fluid can enter or exit the shaft. Thus, for example, it is conceivable that an inlet opening for delivery fluid is provided in the lubrication region in a fluid passage formed in the shaft, the other end opens via an outlet opening in the suction side or in the pressure side of the circulation pump. Delivery liquid can be removed in this way from the lubrication region and the suction side or the pressure side of the circulation pump.

The at least one inlet opening or outlet opening may be a radial opening or an axial opening through which delivery fluid can enter or exit the shaft radially or axially with respect to the axis of rotation.

In a corresponding manner it can be provided that at least one inlet opening or an outlet opening is formed on the sliding bearing, through which conveying fluid can enter or exit the sliding bearing. The at least one inlet opening or outlet opening may be a radial opening or an axial opening.

Preferably, at least one fluid channel extends axially with respect to the axis of rotation. For example, it is provided to provide one or more axially extending fluid channels on the lubrication region, in particular between the sliding bearing and the shaft. Further, it is possible to provide one or more axial fluid passages in the shaft to discharge or supply delivery fluid from the lubrication region. Via one or more outlet openings, delivery fluid can enter or exit the shaft. This allows, for example, a structurally simple fluid management.

Advantageously, at least one fluid channel is designed as an annular channel or as a partial annular channel in the circumferential direction of the axis of rotation. This makes it possible to distribute delivery fluid, in particular in the circumferential direction of the shaft at the lubrication region and to provide an efficient fluid lubrication between the sliding bearing and the shaft. The ring or the partial ring channel can be formed in particular between the sliding bearing and the shaft.

It proves to be favorable if at least one fluid channel is designed as a radial channel with respect to the axis of rotation. At least one and preferably a plurality of radial channels are formed, for example, on a thrust bearing of the circulating pump, on which the rotor can be supported against axial movement relative to the stator. In the circumferential direction of the axis of rotation support elements, for example in the form of webs can be arranged between the radial fluid channels. About the support elements, the thrust bearing can be supported in particular on the sliding bearing. By the delivery fluid in the radial fluid channels is thereby also a Fluid lubrication between the thrust bearing and the sliding bearing allows. Radially outside the fluid channels may be arranged on the thrust bearing a sealing element of the sealing device, which preferably comprises or is formed by the thrust bearing.

Conveniently, a filter element is arranged in at least one fluid channel for filtering the pumped liquid. The filter element is preferably arranged in a fluid channel, which is upstream of the lubrication region in relation to the flow direction of the conveying fluid of the fluid guide. Particles present in the delivery fluid can thereby be filtered out of the delivery fluid before entering the lubrication region and do not affect fluid lubrication. Damage to the plain bearing and / or the thrust bearing by entering the lubrication area particles can be avoided.

The at least one filter element is held, for example, non-positively and / or positively in the at least one fluid channel. For example, the filter element is pressed into the fluid channel. The filter element may in particular be a sintered filter.

It is advantageous if at least one fluid channel is arranged on the sealing device, wherein the sealing device is favorably positioned on the sliding bearing. For example, the sealing device, will be discussed below, be arranged axially adjacent to the sliding bearing, so that an axial sealing of the lubrication region can be ensured. At the sealing device, especially in a sliding bearing contacting the sealing device, a fluid channel may be formed. For example, at least one radial fluid channel or a ring or partial ring channel is provided.

In a structurally simple embodiment of the circulation pump, the sliding bearing surrounds the shaft preferably annular in the circumferential direction of the axis of rotation.

Preferably, the circulation pump comprises a thrust bearing for supporting the rotor against axial movement relative to the stator, in particular due to impeller thrust. This can ensure that the rotor maintains a desired position relative to the stator in order to ensure reliable operation of the circulation pump. A "lifting" of the rotor, as may occur in generic circulating pumps especially at high speeds of the conveyor element ("impeller thrust") can be avoided.

Preferably, the thrust bearing is axially supported on the sliding bearing. As a result, for example, a compact construction of the circulation pump can be achieved. The thrust bearing and the sliding bearing can comprise cooperating support elements, in particular they can lie flat against one another.

At the axial bearing, at least one fluid channel is preferably arranged, for example the fluid guide. This makes it possible to arrange the lubrication region on the thrust bearing and thereby achieve fluid lubrication on the thrust bearing. For example, the thrust bearing is lubricated against the sliding bearing on which it can be supported axially.

It is advantageous if the thrust bearing is rotatably connected to the shaft. A supporting force for supporting the rotor can thereby be effectively introduced to the shaft enclosed by the rotor.

The thrust bearing is favorably annular or disk-shaped and surrounds the shaft in the circumferential direction of the axis of rotation.

The sliding bearing is preferably arranged between the axial bearing and the conveying element. It turns out in practice that thereby a compact design of the circulation pump can be achieved.

Advantageously, a sealing element of the sealing device is arranged on the axial bearing, especially in the last-mentioned advantageous embodiment of the circulating pump. For example, this gives the possibility to seal the lubrication region axially and / or radially with the sealing element and at the same time to enable a support of the rotor via the axial bearing on the sliding bearing.

It is favorable if a sealing element of the sealing device is positioned axially between the axial bearing and the slide bearing.

It is expediently provided that the axial bearing forms an axial support element for a sealing element of the sealing device. The thrust bearing and the sealing element can form cooperating support elements, in particular abutting support surfaces. It can be provided that the thrust bearing is axially supported on the sealing element, which in turn can be supported on the sliding bearing and allows an axial and / or radial sealing of the lubrication region.

Preferably, a sealing element of the sealing device is formed integrally with the axial bearing. By this it can be specifically understood that the axial bearing comprises or forms a sealing element of the sealing device. This allows a structurally simple design of the circulation pump.

The thrust bearing can be made, for example, from a hard metal, in particular with integral design of the sealing element. It is also conceivable that the thrust bearing is made of a ceramic, for example of aluminum oxide or silicon carbide or of carbon (carbon graphite)

In another advantageous embodiment of the circulation pump according to the invention, a sealing element of the sealing device is advantageously formed separately from the axial bearing.

It is conveniently provided that a sealing element of the sealing device is connected to the axial bearing. For example, the sealing element lies flat against the axial bearing, wherein it is preferably arranged between the axial bearing and the plain bearing.

The sealing element can be connected in a rotationally fixed manner to the axial bearing.

It proves to be advantageous if a sealing element of the sealing device at least partially surrounds the axial bearing in the circumferential direction with respect to the axis of rotation. For example, the sealing element can be configured in strip-shaped or annular fashion, for example as an O-ring arranged on the outer circumference of the axial bearing.

In a different advantageous embodiment of the circulation pump according to the invention, the sealing device is preferably arranged on the opposite side of the slide bearing of the thrust bearing. By this may be understood, in particular, that the slide bearing and the sealing device are positioned axially opposite sides of the thrust bearing. For example, delivery fluid can flow around the thrust bearing and enable fluid lubrication against the sliding bearing. On the opposite side, the sealing device may be arranged to seal the lubrication area.

It proves to be advantageous if the sealing device comprises or forms a mechanical seal with a sliding ring, which is rotationally fixed relative to the stator and with a non-rotatably connected to the shaft counter ring. For example, the seal ring is rotatably held on the below-mentioned partition member, which rotatably held on the housing of the circulating pump and thus rotatably relative to the stator. The sliding ring and the counter ring are cooperating sealing elements of the sealing device.

In a structurally simple embodiment of the circulating pump, it is advantageous if the sliding ring is formed by the sliding bearing and the counter-ring is formed by a thrust bearing of the circulating pump. Separate, different from the plain bearing and the thrust bearing sealing elements can be saved and the circulating pump are given a compact design over a structural simplification.

Conveniently, the sliding ring and the mating ring are biased by a biasing member against each other. This can ensure a reliable sealing of the lubrication area. The biasing element is an elastic element, for example a corrugated spring or a packet of corrugated springs, over which or the sliding ring is supported. For example, the sliding ring is supported on the separating part mentioned below or on a non-rotatably connected to this support element.

Preferably, a sealing element of the sealing device is designed annular or disk-shaped and arranged in a plane perpendicular to the axis of rotation. For example, a sealing element formed integrally with the axial bearing or a sealing element connected to the axial bearing is arranged in the shape of a ring or disc and arranged in a plane perpendicular to the axis of rotation.

It can be provided that the sealing device has exactly one sealing element.

It is advantageous if the circulating pump has a separating part which separates the lubrication region from the gap between the stator and the rotor, wherein the separating part is arranged at least in sections, in the radial direction relative to the axis of rotation, between the shaft and the gap. For example, the separator may be at least partially sleeve-shaped and coaxially aligned with the shaft and surround the shaft and in turn be surrounded by the gap.

It is advantageous if the separating part comprises or forms a cover which covers a delivery space of the circulating pump, in which the delivery element is arranged, to the gap between the stator and the rotor. As a result, it can be largely avoided that delivery fluid from the delivery chamber penetrates into the gap. A fluid flow, which can cause the deposition of magnetic particles in the gap, can thereby be largely avoided. The cover is conveniently fluid-tight or substantially fluid-tight.

Preferably, the sliding bearing is held on the separating part. This allows a constructive simplification of the circulation pump. The sliding bearing is in particular held radially on the inside of the separating part and surrounds the shaft in the circumferential direction of the axis of rotation.

Preferably, the separating member is rotationally fixed relative to the stator, whereby also a constructive simplification of the circulation pump can be achieved.

In general, it can be provided that a holder of the sliding bearing, with which holder the sliding bearing is otherwise held on the circulating pump, is rotationally fixed relative to the stator.

The lubrication region is preferably adjoined in the axial direction by a rotor space, which is sealed by the sealing device relative to the lubrication region. The seal does not necessarily have to be perfect. Thus, it may be permitted that delivery fluid enters the rotor space, so that the rotor space gradually filled with liquid and / or liquid can pass from the rotor space in the lubrication region. The volume flow between the rotor chamber and the lubrication region is in particular negligible relative to the volume flow through a fluid guide.

In the case of the last-mentioned advantageous embodiment of the circulating pump according to the invention, it can be provided that the rotor space is fluid-connected to the gap between the stator and the rotor. This makes it possible to hold delivery fluid in the rotor space and in the gap between the stator and the rotor, but at the same time largely avoid accumulation of magnetic particles in the gap. By keeping the delivery liquid available, heat removal at the gap can nevertheless be ensured.

To achieve a compact construction of the circulation pump, it is advantageous if the conveying element and the slide bearing are arranged in the axial direction on the same side of the sealing device, on the opposite side of the rotor space is arranged.

The rotor space and the lubrication area are arranged in particular on opposite sides of the axial bearing.

It is advantageous if the shaft passes through the sealing device axially and if the rotor comprises a magnet holder, which is rotatably connected in the rotor chamber with the shaft to which magnetic holder at least one permanent magnet of the electromagnet is held. This allows a compact construction of the circulation pump, in which with respect to the axis of rotation, the conveying element, the sliding bearing, the sealing device, the thrust bearing and the magnet holder are arranged on the shaft.

It can be provided that the rotor space is fluidly connected via the rotor to a delivery chamber of the circulation pump, in which the delivery element is arranged. For example, a fluid connection is made through the shaft, in which for this purpose at least one fluid channel can be formed. Also in this embodiment, an entry of pumped liquid into the rotor chamber can be made possible, but in this case too the volume flow of pumped liquid into the rotor chamber is negligibly small compared to the volume flow due to a fluid guide.

It is advantageous if the circulation pump comprises a pumping device, with which the delivery fluid can be conveyed through the lubrication region. With the pumping device, a kind of a "lubrication pump", a fluid flow for better supply and removal of pumped liquid can be ensured. The pumping device is, for example, a friction pump (friction pump). The pumping device is preferably drivable by the rotor.

The amount of delivered with the pumping device delivery liquid is preferably independent or substantially independent of the operating point of the circulation pump. In the present case, this can be understood in particular to mean that the quantity of delivery fluid is independent or substantially independent of the differential pressure of the circulation pump. This makes it possible to avoid, with the pumping device to promote more fluid than required by the lubrication area to prevent unnecessary wear on the sliding bearing and the shaft by entrained in the fluid transporting particles.

It may be provided that the rotor is an inner rotor which has one or more permanent magnets, which are arranged with respect to the axis of rotation radially inwardly of the stator.

Alternatively it can be provided that the rotor is an outer rotor having one or more permanent magnets, which are arranged with respect to the axis of rotation radially outside of the stator.

As already mentioned, the electric motor may in particular be an electronically commutated electric motor. In an electronically commutated electric motor can be achieved using the teaching of the invention, a high efficiency. This is possible, for example, in that only a small gap can be provided between the stator and the rotor in order to allow effective magnetic flux from the stator to the rotor. At the same time, undesirable accumulation of magnetic particles in the gap can be largely avoided.

The following description of preferred embodiment of the invention is used in In connection with the drawing, the detailed explanation of the invention. Show it:

1 a longitudinal sectional view of a first preferred embodiment of a circulating pump according to the invention;

2 : an enlarged view of detail A in 1 ;

3 : a representation accordingly 2 in a further embodiment of a circulating pump according to the invention;

4 : a representation accordingly 2 in a further embodiment of a circulating pump according to the invention;

5 a longitudinal sectional view of another preferred embodiment of a circulating pump according to the invention;

6 : a representation accordingly 2 in a further embodiment of a circulating pump according to the invention and

7 a longitudinal sectional view of another preferred embodiment of a circulating pump according to the invention.

An in 1 in section shown first preferred embodiment of a circulating pump according to the invention is generally denoted by the reference numeral 10 busy. At the circulation pump 10 it is a heating pump for conveying a pumped liquid, in this case in particular water.

A housing 12 the circulation pump 10 comprises a housing lower part 14 and an upper housing part 16 , which are sealingly connected to each other, for example by screwing and under the support of one or more sealing elements, such as a sealing ring 18 ,

In a recording room 20 that is between the housing base 14 and the upper housing part 16 is formed, comprises the circulation pump 10 an electric motor 22 that is a stator 24 and a rotor 26 having. The stator 24 is on a housing base 14 formed paragraph 28 positioned and includes in a conventional manner coils that a controller 30 of the electric motor 22 can be energized. Via an only indicated control line 32 is the controller 30 with the stator 24 in electrical connection.

A membrane 34 seals the stator 24 opposite the recording room 20 by the way. The recording room 20 Incidentally, fluid is filled with the conveying liquid, in this case water, which will be discussed below. The membrane 34 is on the sealing ring 18 between the housing parts 14 and 16 clamped.

The rotor 26 has a central in the housing 12 arranged wave 36 on that a rotation axis 38 Are defined. At the wave 36 is rotatably a conveyor element 40 held for conveying water, in this case one about the axis of rotation 38 rotatable conveyor wheel 42 , The conveyor wheel 42 is below an upper housing wall 44 of the upper housing part 16 in the recording room 20 arranged. A central passage opening 46 in the upper housing wall 44 is in a manner not shown with a supply line of the circulation pump 10 connected, so that this circulating water can be supplied. The area above the conveyor wheel 42 , the passage opening 46 facing, corresponds to a suction side 48 the circulation pump 10 ,

About a likewise not shown in the drawing discharge line can by means of the feed wheel 42 pumped water from the circulation pump 10 be delivered. A printed page 50 the circulation pump 10 extends in the circumferential direction of the feed wheel 42 around the axis of rotation 38 , Circulated water can be the case 12 leave radially or tangentially through the discharge line, not shown.

"Axial" and "radial" are present on the axis of rotation 38 to refer to.

For storage of the shaft 36 includes the circulation pump 10 a plain bearing 52 , The plain bearing 52 includes two below the conveyor wheel 42 , in the housing lower part 14 enclosed area of the recording room 20 , two bearing elements 54 and 56 , The bearing elements 54 and 56 are each configured as axially spaced-apart bearing rings 55 and 57 that the wave 36 Surrounded in the circumferential direction.

The bearing rings 55 and 57 are solid-state bearing rings, such as graphite. Between the plain bearing 52 and the wave 36 there is a storage gap. At the bearing gap is a lubrication area 58 arranged in which the sliding bearing by means of the conveyed liquid (water) with respect to the shaft 36 is liquid lubricated. This will be discussed below.

The bearing rings 55 and 57 are at a separator 60 the circulation pump 10 held, which is a hollow cylindrical, sleeve-shaped section 62 having. The conveyor wheel 22 facing the sleeve-shaped section goes 62 into a substantially lid-shaped section 64 of the separator 60 , The lid-shaped section 64 is just like the membrane 34 between the housing parts 14 and 16 on the sealing ring 18 clamped and rotationally fixed relative to the housing 12 educated.

Below the bearing ring 57 , axially at the level of the paragraph 28 , instructs the circulation pump 10 a rotationally fixed to the shaft 36 held thrust bearing 66 on. The thrust bearing 66 serves on the one hand to support the rotor 26 in the axial direction. For this purpose contacted the thrust bearing 66 the bearing ring 57 flat, the thrust bearing 66 and the bearing ring 57 form so cooperating support elements with support surfaces arranged thereon for surface support to each other.

On the other hand serves the thrust bearing 66 also for sealing the lubrication area 58 , will be discussed below.

Axial closes to the thrust bearing 66 a rotor space 68 as a section of the recording room 20 at. The rotor space 68 is hollow-calotte-shaped and is on the bottom side of a lower housing wall 70 of the housing base 14 limited. The lower housing wall 70 goes over in the paragraph 28 , The membrane 34 is in the rotor space 68 arranged and separates a first, the shaft 36 facing space region fluid-tight from a second space area, which is the housing wall 70 is facing.

A magnetic holder 72 of the rotor 26 is in the rotor space 68 rotatably with the shaft 36 connected. The magnetic holder 72 is configured in the form of a radially widening sleeve whose diameter in the region of the stator 24 larger than in the area of the rotor space 68 , At the magnetic holder 72 are permanent magnets 74 of the rotor 26 held. The permanent magnets 74 interact with those of the stator 24 generated alternating magnetic fields to the rotor 26 to turn.

Axial extend the permanent magnets 74 and the holding portion of the magnet holder 72 over the length of the stator 24 and from the bearing ring 55 to the bearing ring 57 , Radial are the permanent magnets 74 and the holding portion of the magnet holder 72 between the sleeve-shaped section 62 and the membrane 34 positioned.

Between the permanent magnets 74 and the membrane 34 is a gap 76 arranged. The gap 76 is very narrow, for example in the millimeter range or in the submillimeter range. The membrane 34 and the gap 76 be from those of the stator 24 generated alternating fields interspersed and act on the permanent magnets 74 one. The narrowness of the gap 76 allows a high magnetic flux, allowing the circulation pump 10 has a high efficiency. For this purpose, the electric motor 22 designed in particular as an electronically commutated electric motor.

As already mentioned, the plain bearing is 52 concerning the wave 36 liquid lubricated. The lubrication area 58 stands with a pump room 78 as a section of the recording room 20 in fluid communication. In the pump room 78 is the conveyor wheel 42 arranged.

To achieve effective fluid lubrication, the lubrication area 58 Fluid channels arranged. These can be considered as a fluid guide 80 the circulation pump 10 are considered to be feeding, performing and discharging conveyed liquid to the lubrication area 58 , through the lubrication area 58 through and away from the lubrication area 58 , The fluid guide 80 comprises at least one and preferably a plurality of fluid channels. The or the fluid channels are between the bearing rings 55 and 57 on the one hand and the wave 36 on the other hand formed as well as on the thrust bearing 66 and in the wave 36 ,

A bearing gap between the sliding bearing 52 and the wave 36 can form a fluid channel.

For example, the fluid guide comprises 80 axial fluid channels 82 between the bearing rings 55 and 57 and the wave 36 are formed ( 1 and 2 ). The fluid channels 82 For example, by recesses on the bearing rings 55 . 57 at the shaft 36 be formed facing side. The recesses are, for example, groove-shaped and extend in the axial direction. In the circumferential direction of the axis of rotation 38 can the fluid channels 82 extend over a limited angular range. It is also conceivable that the fluid channels 82 axially sections as ring channels around the shaft 36 are formed. Instead of the fluid channels 82 can also in the bearing rings 55 and 57 be formed extending fluid channels.

The fluid channels 82 allow the pumped liquid from the pumping room 78 in the lubrication area 58 enter and thus an effective lubrication between the plain bearing 52 and the wave 36 to enable. The lubrication proves to be advantageous for a reduction in wear and the dissipation of heat and thereby favoring a reliable operation of the circulation pump 10 ,

The fluid guide 80 further comprises at least one and, as in the present case, preferably a plurality of fluid channels 84 , The fluid channels 84 are radial channels that serve as recesses on the thrust bearing 66 are formed. The fluid channels 82 on the bearing ring 57 open into the fluid channels 84 , so that delivery fluid to the fluid channels 84 can be transported.

In the circumferential direction between the fluid channels 84 are webs available, which Support elements form over which the thrust bearing 66 on the bearing ring 57 is applied. Radially outside the fluid channels 84 , at the shaft 36 opposite side, is an annular area 86 arranged. At the area 86 has the thrust bearing 66 a flat support element for supporting on the bearing ring 57 on. The area 86 seals the lubrication area 58 from (see below).

Alternatively or in addition to the radial fluid channels 84 it is also possible for spiral-shaped, annular or partially annular fluid channels to be present.

For lubrication between the thrust bearing 66 and the sliding bearing 52 a gap between them may be sufficient without the thrust bearing 66 or on the plain bearing 52 a fluid channel needs to be present.

Between the thrust bearing 66 and the section 62 is an annular gap 87 educated.

The fluid guide 80 further includes, as mentioned, in the shaft 36 formed fluid channels. These fluid channels open via inlet openings 88 in the fluid channels 82 on the bearing ring 57 and the fluid channels 84 , The entrance openings 88 are on the outer circumference of the shaft 36 educated. Through the inlet openings 88 through can delivery fluid into the shaft 36 enter and axially in the direction of the suction side 48 stream. The suction side 48 are facing on the shaft 36 outlet openings 90 formed, through the delivery fluid from the shaft 36 can escape. The outlet openings 90 are, for example, see 1 , on the outer circumference of the shaft 36 arranged or on a front side thereof.

Overall, by the fluid guide 80 effective lubrication at the lubrication area 58 allows. Delivery fluid can from the pressure side 50 through the fluid channels 82 . 84 and the fluid channels in the shaft 36 to the suction side 48 the circulation pump 10 be guided. Lubrication takes place between the plain bearings 52 and the wave 35 and between the thrust bearing 66 and the sliding bearing 52 ,

The circulation pump 10 includes a sealing device 92 for sealing the lubrication area 58 relative to the rotor space 68 , The sealing device 92 includes a sealing element 93 that in the case of in the 1 and 2 embodiment shown integrally by the thrust bearing 66 is trained. For this purpose, the thrust bearing 66 For example, be made of a ceramic material, in particular aluminum oxide (Al ₂ O ₃ ) or silicon carbide (SiC).

For sealing the lubrication area 58 serves the area 86 radially outside the fluid channels 84 , Between the thrust bearing 66 and the bearing ring 57 are formed in this way cooperating axial sealing surfaces, which present in the circumferential direction of the axis of rotation 38 run. The thrust bearing 66 and the bearing ring 57 Form a mechanical seal in this way 104 out.

The sealing of the lubrication area 58 relative to the rotor space 68 does not need to be perfect here. The seal, however, is so extensive that the volume flow of the fluid from the lubrication area 58 to the rotor space 68 through the area 86 and the gap 87 is negligible with respect to the volume flow through the lubrication area 58 to ensure fluid lubrication on the same.

The sealing of the lubrication area 58 relative to the rotor space 68 is of importance here, because the rotor space 68 in fluid communication with the gap 76 between the stator 24 and the rotor 26 stands. The seal can be used to ensure that there is no appreciable flow of fluid through the gap 76 through trains. This is significant because of the gap 76 , as mentioned, is very narrow.

By avoiding a significant fluid flow can be largely prevented that in the fluid conveyed magnetic particles carried on the permanent magnet 74 and thereby to a collection in the gap 76 to lead. This accumulation observed in generic circulating pumps results in increased friction between the stator and the rotor. The friction leads to undesirable wear, unwanted heat generation, noise and can lead to failure of the circulation pump. In particular, it is critical to loop through the membrane 34 , whereby conveying fluid in the electrical section of the receiving space 20 can penetrate.

These disadvantages can be achieved by the inventive design of the circulation pump 10 be avoided, where the lubrication area 58 relative to the rotor space 68 and with it to the gap 76 is sealed.

Furthermore, a substantially fluid-tight seal of the gap takes place 76 concerning the delivery room 78 over the separator 60 , In particular, the lid-shaped section covers 64 of the separator 60 the delivery room 78 in the direction of the gap 76 essentially fluid-tight. In addition, there is a substantially fluid-tight sealing of the lubrication region 58 over the sleeve-shaped section 62 to the magnetic holder 72 , This is also done via the seal between the thrust bearing 66 and the bearing ring 57 ,

The gap 76 and the rotor space 68 , which are fluidly connected to each other, are still filled with pumped liquid. In small quantities can conveyed fluid from the lubrication area 58 at the sealing device 92 over the gap 87 in the rotor space 68 and in the gap 76 enter. However, this volume flow is negligible compared to the volume flow through the lubrication area 58 therethrough.

The provision of pumped liquid in the gap 76 allows, for example, a heat dissipation.

The 3 and 4 show further embodiments (reference numerals 140 respectively. 150 ) a circulating pump according to the invention, partially in one of 2 the circulation pump 10 corresponding representation. 5 shows in sectional view a total with the reference numeral 94 occupied preferred embodiment of a circulating pump.

Same or equivalent features and components of the circulation pump 10 on the one hand and the circulation pump 94 and the circulating pumps shown in detail 140 respectively. 150 on the other hand, the same reference numerals. The above advantages of the circulation pump 10 can with the other circulation pumps 140 . 150 and 94 also be achieved, so that reference can be made in this respect to the above explanations.

At the in 3 illustrated embodiment 140 is the sealing device 92 different from the circulation pump 10 not integral with the thrust bearing 66 educated.

Instead, the thrust bearing and a sealing element 98 the sealing device 92 in the embodiment 140 according to 3 second split. The thrust bearing 66 forms a carrier element 96 axially from the bearing ring 57 is spaced. Between the carrier element 96 and the bearing ring 57 is the sealing element 98 the sealing device 92 arranged. The sealing element 98 is annular and connected to this and forms the sealing area 86 out. The connection is made at adjacent axial contact surfaces over which the carrier element 96 flat on the sealing element 98 abuts and can be supported on this.

Radially inside with respect to the sealing element 98 are the fluid channels 84 formed to a liquid lubrication against the bearing ring 57 sure. The webs between the fluid channels 84 allow a support of the thrust bearing 66 on the bearing ring 57 ,

In the embodiment 150 according to 4 has the thrust bearing 66 on the outer circumference a recess in the form of a circumferential annular groove 100 on. The sealing device 92 has a sealing element in the form of an O-ring 102 on top of the ring groove 100 is used. The sealing of the lubrication area 58 relative to the rotor space 68 takes place opposite the sleeve-shaped portion 62 , In particular, the sealing surfaces extend on the outer circumference of the axial bearing 66 and on the inner circumference of the sleeve-shaped portion 62 , Incidentally, the thrust bearing 66 the fluid channels 84 formed, and the thrust bearing 66 can get over the webs between the fluid channels 84 on the bearing ring 57 support.

The circulation pump 10 includes the electric motor 22 , which in the present case is a so-called "internal rotor". The internal rotor are the permanent magnets 74 radially inward with respect to the stator 24 arranged. The circulation pump 94 In contrast, includes the electric motor 22 , which is formed in this embodiment as a so-called "external rotor". In external rotor are the permanent magnets 74 radially outside the stator 24 positioned and revolve during rotation of the rotor 26 ,

At the circulation pump 94 is the stator 24 on the separator 60 held and on whose the slide bearing 52 attached away from the outside. The membrane 34 seals the stator 24 in the direction of the rotor space 68 and the gap 76 from. A seal of the stator in the direction of the delivery chamber 78 is through the lid-shaped section 64 of the separator 60 ensured.

The sealing of the lubrication area 58 relative to the gap 76 at the circulation pump 94 takes place in the same way by means of the thrust bearing 66 that the sealing element 93 the sealing device 92 integral forms, according to the in the 1 and 2 illustrated embodiment. Of course, in further embodiments, in which an electric motor 22 with external rotor is used, a seal of the lubrication area 58 relative to the rotor space 68 as in the embodiments according to the 3 or 4 respectively.

In the embodiments of the circulating pump according to the invention in the 1 and 2 is the sealing device 92 as a mechanical seal 104 designed. As a sliding ring rotatably acts on the separator 60 held bearing ring 57 , which is the counter-ring in the form of the thrust bearing 66 sealingly contacted.

6 shows in one of the 2 corresponding manner, in sections, another advantageous embodiment of a circulating pump according to the invention (reference numerals 160 ). In the 6 shown construction could in a circulating pump with inner rotor according to 1 or with outer rotor according to 5 be used.

For identical or equivalent features and components identical reference numerals are used.

At the circulation pump 160 according to 6 the fluid channels extend 84 in the radial direction over the entire width of the thrust bearing 66 , The fluid guide 58 thus also extends into the fluid channels 84 so that the thrust bearing 66 opposite the bearing ring 57 can be lubricated effectively.

The sealing device 92 is on the plain bearing 52 opposite side of the thrust bearing 66 arranged and includes a mechanical seal 104 , It is a sliding ring 106 provided, the rotationally fixed to the sleeve-shaped portion 62 is held and thus rotationally fixed relative to the stator 24 is. A sealing element, for example in the form of an O-ring 108 seals between the sliding ring 106 and the section 62 ,

The sliding ring 106 is based on a mating ring 110 , which rotates with the shaft 36 connected is. The sliding ring 106 and the mating ring 110 are sealing elements 112 . 114 the mechanical seal 104 , Their cooperating sealing surfaces allow the lubrication area 58 relative to the rotor space 68 seal. Conveying fluid coming out of the lubrication area 58 through the gap 87 in the space between the thrust bearing 66 and the mechanical seal 104 flows, can thus largely before entering the rotor space 68 be prevented. As in the case of the circulation pump 10 However, it is possible that pumped liquid in small quantities in the rotor space 68 can enter, so that it is also filled with liquid.

At the section 62 is also a ring 116 held against rotation. The ring 116 forms a support element, which is an elastic element 118 can support. The elastic element 118 in turn is based on the sliding ring 106 off, leaving the slip ring 106 over the elastic element 118 with one on the counter ring 110 acting force is applied. The elastic element 118 is for example a corrugated spring or a Wellfederpaket.

In the previous advantageous embodiments of the circulation pump, the delivery fluid flows from the pressure side 50 the circulation pump to the suction side 48 , so that the delivery fluid first through the bearing gap between the sliding bearing 52 and the wave 36 and then through the wave 36 through to the suction side 48 flows.

7 shows a further preferred embodiment of a circulation pump according to the invention, in which the flow direction of the pumped liquid through the lubrication region 58 is reversed. Such a construction could also in the advantageous embodiments 140 . 150 . 94 . 160 of the 3 . 4 . 5 and 6 be used.

In the 7 shown circulating pump is generally indicated by the reference numeral 120 busy. For identical or equivalent features and components identical reference numerals are used in this case.

At the circulation pump 120 is in the wave 36 a central fluid channel 122 available. It accounts for the outlet openings 90 , Instead, the fluid channel 122 opposite the suction side 48 with a closure element 124 locked. The closure element 124 is for example one in the fluid channel 122 pressed plug.

Pressure side in the pump room 78 at the slide bearing 52 facing side is an entrance channel 126 in the wave 36 educated. About the entrance channel 126 the pumping room opens 78 into the wave 36 , Near the entrance channel 126 is a rotation with the shaft 36 connected element 128 in the pump room 78 arranged. The element 128 is configured, for example, disk-shaped. Under rotation of the element 128 is combined with the bearing ring 57 in the pump room 78 a friction pump (friction pump) is formed. Delivery fluid is via the inlet channel 126 in the fluid channel 122 pumped.

In the fluid channel 122 is a filter element 130 arranged. For example, the filter element 130 by compression in the fluid channel 122 held. In the filter element 130 it may in particular be a sintered filter.

About exit channels 132 becomes a fluid connection between the fluid channel 122 and the lubrication area 58 at the fluid channels 84 provided. Delivery fluid can through the fluid channel 122 over the exit channels 132 in the fluid channels 84 and 82 be encouraged. Through the filter element 130 be filtered in the fluid flow particles, so that they are not in the lubrication area 58 can enter. The accumulation of particles in the lubrication area 58 is avoided. This has a favorable effect on the bearing of the shaft 36 and fluid lubrication at the lubrication area 58 out.

Furthermore, it is advantageous that the amount of the conveying fluid from the dimensioning of the friction pump between the sliding bearing 52 and the element 128 depends and thus essentially independent of the operating point of the circulation pump 120 is. Unnecessary wear on the plain bearing 52 and the wave 36 by entrained particles and excessive clogging of the filter element 130 are avoided.

LIST OF REFERENCE NUMBERS

10

 circulating pump

12

casing

14

Housing bottom

16

Housing top

18

seal

20

accommodation space

22

electric motor

24

stator

26

rotor

28

paragraph

30

control

32

control line

34

membrane

36

wave

38

axis of rotation

40

 impeller

42

conveyor wheel

44

upper housing wall

46

Through opening

48

suction

50

pressure side

52

bearings

54

 bearing element

55

 bearing ring

56

 bearing element

57

bearing ring

58

 lubrication area

60

separating part

62

 sleeve-shaped section

64

 lid-shaped section

66

 thrust

68

 rotor chamber

70

 lower housing wall

72

 magnetic holder

74

 permanent magnets

76

gap

78

delivery chamber

80

fluid guide

82

 fluid channels

84

fluid channels

86

 Area

87

 gap

88

 inlet openings

90

 outlet openings

92

 sealing device

93

 sealing element

94

 circulating pump

96

 support element

98

 sealing element

100

 ring groove

102

 O-ring

104

 Mechanical seal

106

 sliding ring

108

 O-ring

110

 counter ring

112

 sealing element

114

 sealing element

116

 ring

118

 elastic element

120

 circulating pump

122

 fluid channel

124

 closure element

126

 inlet channel

128

 element

130

 filter element

132

 outlet channels

140

 circulating pump

150

 circulating pump

160

 circulating pump

Claims (40)

Circulation pump, comprising a conveying element ( 40 ) for conveying a delivery fluid and an electric motor ( 22 ), which has a stator ( 24 ) and a rotor ( 26 ), between which a gap ( 76 ) is formed, wherein the rotor ( 26 ) one about a rotation axis ( 38 ) rotatable shaft ( 36 ), with which the conveying element ( 40 ) is rotationally connected, and wherein the circulation pump ( 10 ; 94 ; 120 ) a radial sliding bearing ( 52 ) for supporting the shaft ( 36 ), which at a lubrication area ( 58 ) is liquid-lubricated with the conveying liquid, characterized in that the circulating pump ( 10 ; 94 ; 120 ) a sealing device ( 92 ), which provides a fluid connection between the lubrication region ( 58 ) and the gap ( 76 ) between the stator ( 24 ) and the rotor ( 26 ) stops. Circulation pump according to claim 1, characterized in that the circulating pump ( 10 ; 94 ; 120 ) a fluid guide ( 80 ), which comprises at least one fluid channel through which fluid can pass ( 82 . 84 . 88 . 122 ) for supplying, passing or discharging conveyed liquid into, through or out of the lubrication region ( 58 ). Circulation pump according to claim 2, characterized in that a fluid channel ( 82 ) via at least one inlet opening with a pressure side ( 50 ) or suction side ( 48 ) of the circulation pump ( 10 ; 94 ; 120 ) is fluid-connected and / or that a fluid channel via at least one outlet opening ( 90 ) with a pressure side ( 50 ) or suction side ( 48 ) of the circulation pump ( 10 ; 94 ) is fluidly connected. Circulation pump according to one of the preceding claims, characterized in that at the lubrication area ( 58 ) at least one fluid channel ( 82 . 84 ) is arranged for delivery fluid and / or that the circulation pump ( 10 ; 94 ; 120 ) one Fluid guide ( 80 ) with at least one fluid channel ( 82 . 84 . 122 ) for delivery fluid. Circulation pump according to claim 4, characterized in that at least one fluid channel ( 82 . 122 ) in the plain bearing ( 52 ) or in the wave ( 36 ) is formed. Circulation pump according to claim 4 or 5, characterized in that at least one fluid channel ( 82 ) between the sliding bearing ( 52 ) and the wave ( 36 ) is arranged. Circulation pump according to one of claims 4 to 6, characterized in that on the shaft ( 36 ) at least one inlet opening ( 88 ) or outlet ( 90 ) is formed, through which conveying fluid into the shaft ( 36 ) or can emerge from this. Circulation pump according to one of claims 4 to 7, characterized in that at least one fluid channel ( 82 ) with respect to the axis of rotation ( 38 ) axially. Circulation pump according to one of claims 4 to 8, characterized in that at least one fluid channel as an annular channel or as a partial ring channel in the circumferential direction of the axis of rotation ( 38 ) is configured. Circulation pump according to one of claims 4 to 9, characterized in that at least one fluid channel ( 84 ) as a radial channel ( 84 ) with respect to the axis of rotation ( 38 ) is configured. Circulation pump according to one of claims 4 to 10, characterized in that in at least one fluid channel ( 122 ) a filter element ( 130 ) is arranged for filtering the conveying liquid. Circulation pump according to one of the preceding claims, characterized in that the circulating pump ( 10 ; 94 ; 120 ) an axial bearing ( 66 ) comprises for supporting the rotor ( 26 ) against axial movement relative to the stator ( 24 ). Circulation pump according to claim 12, characterized in that the thrust bearing ( 66 ) on the sliding bearing ( 52 ) is axially supported. Circulation pump according to claim 12 or 13, characterized in that the thrust bearing ( 66 ) at least one fluid channel ( 84 ) is arranged. Circulation pump according to one of claims 12 to 14, characterized in that the thrust bearing ( 66 ) rotatably with the shaft ( 36 ) connected is. Circulation pump according to one of claims 12 to 15, characterized in that a sealing element ( 66 ; 98 ; 102 ) of the sealing device ( 92 ) on the thrust bearing ( 66 ) is arranged. Circulation pump according to one of claims 12 to 16, characterized in that a sealing element ( 98 ) of the sealing device ( 92 ) axially between the thrust bearing ( 66 ) and the plain bearing ( 52 ) is positioned. Circulation pump according to one of claims 12 to 17, characterized in that the thrust bearing ( 66 ) an axial support element for a sealing element ( 98 ) of the sealing device ( 92 ) trains. Circulation pump according to one of claims 12 to 18, characterized in that a sealing element ( 66 ) of the sealing device ( 92 ) integral with the thrust bearing ( 66 ) is formed. Circulation pump according to one of claims 12 to 19, characterized in that a sealing element ( 98 ; 102 ) of the sealing device ( 92 ) separated from the thrust bearing ( 66 ) is formed. Circulation pump according to claim 20, characterized in that a sealing element ( 98 ; 102 ) of the sealing device ( 92 ) with the thrust bearing ( 66 ) connected is. Circulation pump according to one of claims 12 to 21, characterized in that a sealing element ( 102 ) of the sealing device ( 92 ) the thrust bearing ( 66 ) in the circumferential direction with respect to the axis of rotation ( 38 ) at least partially surrounds. Circulation pump according to one of claims 12 to 22, characterized in that the sealing device ( 92 ) on the plain bearing ( 52 ) opposite side of the thrust bearing ( 66 ) is arranged. Circulation pump according to one of the preceding claims, characterized in that the sealing device ( 92 ) a mechanical seal ( 104 ) comprises or forms with a sliding ring ( 57 . 106 ), the rotationally fixed relative to the stator ( 24 ) and one with the wave ( 36 ) rotatably connected counter ring ( 66 . 110 ). Circulation pump according to claim 24, characterized in that the sliding ring ( 57 ) through the plain bearing ( 52 ) is formed and the mating ring ( 66 ) by a thrust bearing ( 66 ) of the circulating pump is formed. Circulation pump according to claim 24 or 25, characterized in that the sliding ring ( 106 ) and the counter ring ( 110 ) by a biasing element ( 118 ) are biased against each other. Circulation pump according to one of the preceding claims, characterized in that a sealing element ( 38 ) of the sealing device ( 92 ) is configured annular or disc-shaped and in a plane perpendicular to the axis of rotation ( 38 ) is arranged. Circulation pump according to one of the preceding claims, characterized in that a sealing element ( 38 ) of the sealing device ( 92 ) is configured annular or disc-shaped and in a plane perpendicular to the axis of rotation ( 38 ) is arranged. Circulation pump according to one of the preceding claims, characterized in that the circulating pump ( 10 ; 94 ; 120 ) a separating part ( 60 ), the lubrication area ( 58 ) from the gap ( 76 ) between the stator ( 24 ) and the rotor ( 26 ), wherein the separating part ( 60 ) at least in sections, in the radial direction relative to the axis of rotation ( 38 ), between the wave ( 38 ) and the gap ( 76 ) is arranged. Circulation pump according to claim 29, characterized in that the separating part ( 60 ) a cover ( 64 ), which forms a delivery room ( 78 ) of the circulation pump ( 10 ; 94 ; 120 ), in which the conveying element ( 40 ), to the gap ( 76 ) between the stator ( 24 ) and rotor ( 26 ) covers. Circulation pump according to claim 29 or 30, characterized in that the plain bearing ( 52 ) on the separating part ( 60 ) is held. Circulation pump according to one of claims 29 to 31, characterized in that the separating part ( 60 ) rotationally fixed relative to the stator ( 24 ). Circulation pump according to one of the preceding claims, characterized in that the lubrication area ( 58 ) in the axial direction a rotor space ( 68 ) connected by the sealing device ( 92 ) relative to the lubrication area ( 58 ) is sealed. Circulation pump according to one of the preceding claims, characterized in that the rotor space ( 68 ) with the gap ( 76 ) between the stator ( 24 ) and the rotor ( 26 ) is fluidly connected. Circulation pump according to claim 33 or 34, characterized in that the shaft ( 36 ) the sealing device ( 92 ) axially and that the rotor ( 26 ) a magnetic holder ( 72 ), which in the rotor space ( 68 ) rotatably with the shaft ( 36 ) is connected to which magnetic holder ( 72 ) at least one permanent magnet ( 74 ) of the electromagnet ( 22 ) is held. Circulation pump according to one of the preceding claims, characterized in that the circulating pump ( 120 ) comprises a pumping device, with the conveying fluid through the lubrication region ( 58 ) is conveyed through. Circulation pump according to claim 36, characterized in that the amount of conveyed with the pumping means conveying fluid independently or substantially independent of the operating point of the circulating pump ( 120 ). Circulation pump according to one of the preceding claims, characterized in that the rotor ( 26 ) an inner rotor ( 26 ), one or more permanent magnets ( 74 ), which with respect to the axis of rotation ( 38 ) radially inward of the stator ( 24 ) are arranged. Circulation pump according to one of claims 1 to 37, characterized in that the rotor ( 26 ) an outer rotor ( 26 ), one or more permanent magnets ( 74 ), which with respect to the axis of rotation ( 38 ) radially on the outside of the stator ( 24 ) are arranged. Circulation pump according to one of the preceding claims, characterized in that the electric motor ( 22 ) an electronically commutated electric motor ( 22 ).

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