DE10221843B4 - Electric motor for use as a pump motor and pump - Google Patents

Abstract

Electric motor (18) for use as a pump motor, with
a stator (40) provided with at least one winding (42),
an outer rotor (50) encompassing the stator (40) and
a motor housing (48) connected to the outer rotor (50) in a rotationally fixed manner and connected to a pump wheel (20),
the motor housing (48) with the outer rotor (50) being rotatably mounted on a fixed shaft (38) holding the stator (40) via a bearing arrangement (32, 54), the bearing arrangement (32, 54) being a first bearing near the pump wheel ( 32) and a second bearing (54) remote from the pump wheel, and the motor housing (48) is sealingly connected to the pump wheel (20) and, together with the pump wheel (20), encapsulates the stator (40) and the outer rotor (50) in a sealed manner.

Description

The The invention relates to an electric motor, in particular an external rotor motor, for use as a pump motor.

Electric motors, especially external rotor motors, are used in various technical areas. An application is to pump a pump of fluids, especially liquids, to drive with an electric motor. Depending on the type and properties of the to be funded Fluid can be provided that the components of the electric motor get in touch with this or that a contact between the Components of the electric motor and the fluid are to be prevented, for example, because they are aggressive, corrosive fluids acts that attack individual engine components and their service life shorten can, or because there is no contamination of highly sensitive fluids should.

11 shows a longitudinal sectional view of a pump with an electric motor according to the prior art, in which the fluid to be delivered can not come into contact with the electrically active components of the electric motor. The pump after 11 is generally referenced 10 ' referred to and designed as a radial pump, ie the fluid to be pumped flows according to arrow P ₁ into a pump inlet and flows radially out of the pump according to arrow P ₂ 10 ' out. The pump 10 ' is with an impeller wheel 12 ' provided, which has radially outwardly directed flow channels. The impeller wheel 12 ' is on a wave 14 ' stored. The wave 14 ' is about a bearing arrangement with a first ball bearing 16 ' and a second ball bearing 18 ' rotatable in a housing 20 ' stored. On the wave 14 ' is also a ring rotatably 22 ' made of soft magnetic material, the rotor magnets on its outer circumference 24 ' wearing. The ring 22 ' and the rotor magnets 24 ' form the one on the wave 14 ' mounted rotor 26 ' , Around the rotor 26 ' there is a stator around 28 ' arranged of a laminated core 30 ' and windings 32 ' includes. The stator 28 ' is non-rotatable with the housing 20 ' and a pot connected to it 34 ' connected. With normal excitation of the windings 32 ' the rotor turns 26 ' inside the stator 28 ' and thus drives the over the camp 16 ' . 18 ' in the housing 20 ' rotatable shaft 14 ' on. The impeller wheel 12 ' driven with, so that it presses the fluid located in its delivery channels due to the centrifugal force generated during rotation according to arrow P ₃ to the outside. A negative pressure arises on the suction side at arrow P ₁ , whereas an excess pressure arises on the pressure side at arrow P ₂ , which leads to a conveying movement of the fluid.

The related to 11 Known, known pump has considerable disadvantages. For one thing, it is relatively difficult in the area of the impeller wheel 12 ' penetration of fluid to be pumped through the bearings 16 ' . 18 ' to prevent the electrically effective components of the motor. For this purpose, elaborate precautions have been taken in the motor shown, such as a labyrinthine design of the impeller wheel 12 ' on the the housing 20 ' facing side, such that two ring projections engage in corresponding ring grooves and thus form a labyrinth seal. In addition, the camp 16 ' at his the impeller wheel 12 ' facing side with a sealing ring 36 ' Mistake. Despite these precautions, it can be due to the impeller wheel 12 ' generated high pressure does not prevent through the labyrinth seal and between the rotating shaft 14 ' and the fixed housing 20 ' arranged ring seal 36 ' fluid to be conveyed penetrates and reaches the area of the electrically active components. This can lead to corrosion formation on the components of the electric drive, particularly in the case of aggressive fluids to be pumped, and under certain circumstances even result in failure of the electric motor. In addition, the spatial separation of the electrically active components leads in particular to the stator 28 ' and rotor 26 ' of the fluid-conveying components, in particular of the impeller wheel 12 ' , to a relatively large volume structure of the pump 10 ' , which can be disadvantageous for various applications in which a small-volume, light pump is required. The large-volume design of the pump 10 ' This is not least due to the fact that the electric motor is built according to the internal rotor principle, ie with a rotating shaft, which is both a complex bearing with two ball bearings 16 ' and 18 ' and also requires a relatively complicated structure of the stator, particularly with regard to the arrangement of the windings as a pull-in winding.

A pump similar construction, as described above, is also from the DE 199 43 862 A1 known. However, in this pump only the electrically active parts of the motor drive are encapsulated by the fluid to be pumped, whereas the fluid to be pumped comes into contact with the rotor designed as an internal rotor. On the one hand, this configuration has the disadvantage that the rotor rotating in the fluid to be conveyed has to perform "flexing work", so that so-called splashing or splashing losses can occur, that is to say losses which arise due to the fluid dynamic resistance caused by the fluid to be conveyed arise. In addition, in this known pump to prevent contact of the fluid to be delivered with the electrically active parts of the stator, it is necessary to provide a partition between the rotor and the stator. However, this means that the magnetic gap between The rotor and stator must be increased, which in turn lowers the magnetic induction B and thus reduces the motor efficiency. Finally, depending on the fluid to be conveyed, there may also be corrosion effects on the rotor around which the fluid to be conveyed flows, and thus a shortening of the service life of the motor drive.

Also with the in the DE 100 25 190 A1 In the solution shown, the rotor designed as an inner rotor comes into contact with the fluid to be pumped, so that the above-mentioned adverse effects, such as splashing losses, reduction in motor efficiency due to an increase in the magnetic gap, and risk of corrosion can occur.

Furthermore, the DE 100 24 953 A1 a pump of similar construction, in which the fluid to be pumped can also penetrate into the area of the motor drive.

In contrast to the previously discussed motor and pump variants according to the prior art, the DE 36 35 297 C2 a motor variant, which is designed as an external rotor motor. In this motor variant, a rotor designed as a ring rotates around a stator which is mounted on a fixed shaft in a rotationally fixed manner. In addition, a cooling fluid is provided in the area of the rotor and stator for cooling in this external rotor motor.

Also in the pump according to DE 199 48 972 A1 an outer rotor, a hub connected to it and a pump wheel rotate about a shaft, the corresponding bearing arrangement comprising a first bearing near the pump wheel and a second bearing remote from the pump wheel. A thin separate sleeve is used to separate the stator space from the rotor space.

In the DE 44 11 960 C2 and pumps described in US 2001/0033800 A1 have a similar arrangement.

Finally, the DE 26 55 317 A1 on the use of an external rotor motor with a compressor blade.

The publication DE 199 48 972 A1 discloses a motor pump with a stator in a stator space which is closed toward the conveying medium-carrying side and a rotor which is provided in a rotor space which is open towards the conveying medium-carrying side. The stator space is formed by two walls and a piece of pipe, the rotor being guided past in the radially outer region of the stator space.

In the DE 100 08 240 A1 The liquid pump shown has an internal stator and an external rotor.

It is the object of the present invention, an electric motor for use to provide as a pump motor and a corresponding pump that with high engine efficiency and simple, small-volume construction one use regardless of influences and properties of the funded Allows fluids.

This Task is performed by an electric motor, in particular an external rotor motor, solved for use as a pump motor, with one with at least a stator provided with a winding, a stator encompassing the stator outer rotor and a rotatable with the outer rotor connected motor housing, which is provided with an impeller wheel (impeller), the motor housing via a Bearing arrangement rotatable on a stationary holding the stator Shaft are mounted, the bearing arrangement is a first impeller wheel Bearing and a second impeller distal bearing includes and the motor housing sealing is connected to the pump wheel and together with the impeller wheel the stator and the outer rotor sealed encapsulates. The motor housing can have a bottle shape, wherein a radial and axial seal can be provided on the bottle neck can.

The Training the electric motor as an external rotor motor enables relatively compact Construction of the engine. By encapsulating the stator and outer rotor in the motor housing can despite the relatively small volume structure a contact of the to be funded Fluids with the electrically effective parts stator and outer rotor effective be prevented. This makes it possible to put the electric motor in a pump with which aggressive media or highly sensitive Media promoted can be.

With regard to the encapsulation of the stator and outer rotor in the hub, it can be provided that the motor housing forms a first hub part and the impeller wheel forms a second hub part. As a result, the hub is produced in a shell-like manner from two hub parts, namely from the motor housing and the impeller wheel, so that the encapsulation can be achieved effectively using parts which are required anyway, and at the same time a reduction in the size of the motor, a reduction in the number of parts and a concomitant cost reduction are possible , In this embodiment of the invention it can be provided that the motor housing is sealingly placed on an annular projection of the impeller wheel. For example, corresponding end faces of the motor housing and impeller wheel can be connected to one another by gluing or pressing. Alternatively, it can be provided that the motor housing is sealing is accommodated in the impeller wheel. For this purpose, it is necessary to provide an annular groove or an annular projection in the impeller wheel, which is used to hold the motor housing.

to Production of a magnetic inference on the outer rotor Is it possible, the motor housing made of a soft magnetic material. So that works motor housing even as a yoke for producing the magnetic yoke, so no additional Component between the motor housing and rotor is to be provided. This measure contributes to further reduction the number of parts and to reduce the construction volume of the electric motor at. However, due to particularly corrosive properties of the to be funded Fluids or for reasons the weight saving from the design of the motor housing a soft magnetic material can be unfavorable, so alternatively be provided from the motor housing a non-magnetic material and between the outer rotor and the motor housing to provide a soft magnetic yoke. In this variant According to the invention, the yoke can be made from soft magnetic material of magnetic inference be placed in the encapsulated area so that a mutual Contact between the yoke and the fluid to be pumped is excluded. The engine case can then for example made of aluminum or inert plastic material or the like.

In addition to the approaches according to the invention already discussed above for It is reduction in the number of parts and size of the electric motor also possible, For this purpose, appropriate precautions on the bearing arrangement make. For example, the first bearing near the impeller wheel be designed as a plain bearing and be axially secured on the shaft. The use of a plain bearing offers the advantage of being relatively small radial expansion with low weight and thus the possibility for further size reduction. Alternatively, it is also possible the first bearing as a rolling bearing, especially as a ball bearing. As a result, improved running properties, in particular, a lower friction, and a longer bearing life can be achieved. Independently by choosing the bearing as a plain bearing or roller bearing can save further be provided by installation space, the first bearing in one in the impeller to classify trained warehouse management. This allows Save axial installation space so that the electric motor is more compact can be.

at Formation of the impeller wheel as a radial conveying device, which is to be conveyed Fluid flows in axially and radially outwards promoted will - that is also under load in the axial direction - it is necessary to Training bearing arrangement to absorb axial forces. This is to clamp them axially. It lends itself to axial bracing especially in the area of the first warehouse, because straight in the vicinity, namely on Impeller wheel, the axial forces attack. For this can In a further development of the invention it can be provided that for the axial Bracing the bearing assembly between the shaft and the impeller spring element preloaded in the axial direction, in particular an elastomer spring element, and a ball engaging the spring element is arranged. The axial forces occurring on the impeller wheel are caused by the ball bearing arrangement recorded and over without play the ball engaging the spring element on the fixed shaft derived. However, there are other measures for axial bracing conceivable, such as attaching disc springs to the first bearing or the like, which also with an axial ring seal between Motor and housing can work together.

Regarding the second bearing can be provided as a plain bearing, in particular as a compact sintered bearing, plastic bearing or ceramic bearing, is trained. Such a training of the impeller wheel second camp is particularly useful if the first Bearings as roller bearings is formed and in the area of the first bearing the above mentioned axial bracing via the preloaded spring element and the ball is provided. For installation-friendly and simple The second bearing can be arranged in a further development of the invention be provided that this is formed in a in the motor housing Warehouse inventory is included.

It has been mentioned several times above that the motor housing, together with the impeller wheel, encapsulates the stator and the outer rotor in a sealed manner. Various seals are provided for this purpose, which will be specified in more detail below. In an embodiment according to the invention, at least one radial seal, in particular at least one mechanical seal or at least one O-ring, can be provided between the shaft and the motor housing in the region of the second bearing. Since this area of the motor housing is relatively far away from the impeller wheel and there are at most low fluid pressures, the precautions to be taken in this area are less complex for an adequate seal. As an alternative or in addition to the mechanical seal or O-ring, it can be provided that at least one spring-loaded radial / axial seal is arranged between the shaft and the motor housing in the region of the second bearing. Furthermore, alternatively or additionally, it can be provided that between the shaft and the motor housing in the area of the second bearing at least one return seal, in particular return thread seal, is provided. In particular, the return thread can be formed either on the shaft or on the motor housing or on a sealing ring between the shaft and the motor housing. The peculiarity of return thread seals lies in the fact that they are arranged essentially in a contactless and therefore friction-free manner between the parts to be sealed off from one another, but only seal inadequately in the absence of relative rotation between these parts. In dynamic operation, i.e. in the case of relative rotation between the two parts to be sealed, it is possible to avoid the occurrence of friction losses and the associated undesirable wear and abrasion effects due to the thread of the return thread seal, so that there is fluid between the two parts to be sealed via the thread valleys of the return thread seal the area to be sealed is promoted. It should be noted that the orientation of the return thread, ie the design as a right-hand or left-hand thread, must be coordinated with the direction of rotation in order to achieve a return effect.

The Training of the electric motor as an external rotor motor with a fixed Shaft has the further advantage of supplying the stator via the To wave. For example, this can be achieved in that the shaft provided with a hole for receiving leads to the stator is. By this measure is guaranteed that the supply lines and the areas to be sealed are perfect can be separated from each other and thus the supply lines the already complex sealing of Leave parts moving towards each other unaffected. This constructive measure leads too at a low cost solid and compact pump motor design.

above were the measures according to the invention analyzed with regard to the design of the electric motor. As at the beginning already indicated, the invention further relates to a pump for Promote Fluids with an electric motor as described above Run on is, wherein the pump with a pump housing receiving the electric motor an inlet and an outlet for feeding and discharging the Has fluids. In this respect, an integrated motor without additional Coupling, bearings, seals and installation space created.

A such a pump is suitable, for example, for use in a cooling circuit a motor vehicle. The use of a separate motor Drive-trained pump has the advantage that the pump only can be switched on if necessary. So the pump is not like a conventional one Toothed belt pump driven by the internal combustion engine of a motor vehicle permanently active, but only when cooling is actually required. Thereby can reduce the overall fuel consumption of the car and the lifespan the pump extended become. Also preheating the engine, catalytic converter or the Auxiliary heating is made possible.

at this pump can be the pump housing be designed such that between it and the motor housing only a thin one Gap is provided. This thin one The gap can certainly fill with fluid to be pumped. Thereby on the one hand achieve a certain level of noise reduction, so that the drive noise caused by the electric motor and emerging through the pump housing fluidic sound absorption in their intensity be reduced. Furthermore, a thin gap filled with fluid provides the further advantage of an improved thermal transmission, so that the dissipation heat generated in the motor when the drive is driven is easier from the motor housing or the hub over the liquid transferred to the pump housing and can be released into the environment. In this It should be noted that in connection with further training the invention the pump housing with cooling fins on its surface facing away from the hub can be trained. this leads to to a surface enlargement and for better heat dissipation from the pump housing.

Although, as stated above, a certain entry of leakage fluid into the thin gap between the pump housing and the motor housing may be desirable, an embodiment variant of the invention can also provide that in an area close to the impeller on the pump housing and / or on the motor housing to seal the gap a gap seal, in particular a sealing ring and / or a return thread seal, is arranged. The provision of such a gap seal should at least limit the amount of leakage fluid entering the thin gap between the pump housing and the motor housing and thus avoid an undesirably high loss of the fluid to be conveyed due to leakage. With regard to the use of a return thread seal, it should be noted that in dynamic operation, i.e. when the impeller wheel rotates, the hub rotates at the speed of the impeller wheel relative to the pump housing, so that the return thread seal provided on it can develop its effect particularly when high Pressures occur on the pressure side of the pump. In dynamic operation, it is therefore possible for these high pressures to spread into the thin gap between the pump housing and the motor housing due to the fluid feedback effect of the feedback valve Avoid wind seals effectively. In the static case, ie when the pump is not in operation, the pressure of the fluid to be pumped is relatively low, so that the leakage fluid entering the thin gap between the pump housing and the motor housing can only penetrate to the second bearing at a low pressure and already on it relatively simple precautions can prevent leakage fluid from penetrating into the motor components of the outer rotor and stator.

Around such penetration of leakage fluid to the second bearing can further contain in one embodiment the invention provide that in a region remote from the impeller motor housing Another gap seal for sealing near the second bearing the gap is provided. This second gap seal can be a Labyrinth seal and / or a ring seal, especially one O-ring, or / and a thread return seal on the sealing bushing. When using a thread return seal can be provided that this with an axial and / or in radial direction oriented thread pitch is formed. You can do this different areas for contour levels of the motor housing provided with thread formations and used for that Sealing effect of the return thread seal continue to improve.

Around despite at least one of the seals described in the thin one Gap leakage fluid penetrated at another advance To prevent the second camp in a further training Invention provided that the gap with an overflow for draining of excess fluid - or else to return to the fluid circuit - connected is.

to electronic surveillance of pump operation and for controlling the drive of the in Pump integrated electric motor can be in a training course Invention can be provided that at least a first on the hub Sensor component and at least a second on the pump housing Sensor components are provided, the first sensor component and the second sensor component detects a relative rotation of the Hub relative to the housing allow. One consisting of the two sensor components Sensor technology leaves themselves under relatively little Place the effort in an area of the pump far from the impeller.

Although discussed above with respect to the prior art radial pumps were, this should not imply that it is in the pump according to the invention exclusively is a radial pump. Rather, the pump according to the invention either as a radial pump, in which the fluid to be pumped in the radial direction is dissipated or be designed as an axial pump in which the pumped Fluid is discharged in the axial direction.

in the In the following, the invention will be exemplified with reference to the accompanying Figures explained. They represent:

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

2 an exploded view of the in 1 shown pump;

3 an exploded view of the according to the pump 1 pump motor used;

4 a longitudinal sectional view of a second embodiment of a pump according to the invention;

5 a longitudinal sectional view of a third embodiment of a pump according to the invention;

6 a longitudinal sectional view of a fourth embodiment of a pump according to the invention;

7 a longitudinal sectional view of a fifth embodiment of a pump according to the invention;

8th a longitudinal sectional view of a sixth embodiment of a pump according to the invention;

9 a longitudinal sectional view of a sixth embodiment of a pump according to the invention;

10 a cross-sectional view of the pump 9 and

11 a longitudinal sectional view of a pump according to the prior art.

In the 1 to 3 is shown a first embodiment of a pump according to the invention, with 10 is designated. The pump 10 includes a pump housing 12 , which consists of a first housing part 14 and a second housing part 16 consists. In the pump housing 12 is a pump motor 18 recorded, at whose in 1 and 2 left end of impeller or impeller 20 is trained.

In the impeller wheel 20 are channels 22 provided, which is located in a radially inner area 24 open in the direction of a longitudinal axis A and which are located in a radially outer region 26 with respect to the longitudinal axis A in an essentially radial direction.

On one of the axial opening 24 opposite side of the impeller wheel 20 is a ring projection 28 educated. Furthermore, the impeller wheel 20 on this side a radially inner ring projection 30 on, in which a ball bearing 32 is included. Radially inside the ring projection 30 is a recess 34 formed with stepped diameter, in the deepest area an elastomeric spring element 36 is inserted. The recess 34 serves to receive a shaft 38 of the motor 10 ,

On the wave 38 is a sheet metal package 40 fixed that with windings 42 is provided. The windings 42 can via feed lines 44 are electrically controlled, the supply lines 44 via a radial bore and an axial bore communicating with it 46 through the wave 38 can be passed through. The supply lines 44 are, for example, by means of a cast-in and hardened synthetic resin material in the axial bore 46 fixed.

On the in the 1 to 3 right side is a pot-like motor housing 48 educated. Inside the engine case 48 is a magnetic ring that serves as an external rotor 50 rotatably attached with individual successive magnetic elements in the circumferential direction. On that in the 1 to 3 right end of the engine case 48 this is with a diameter step 52 trained as a receptacle for a plain bearing bush 54 serves.

When installing the in 3 the pump motor shown in an exploded view is the shaft 38 into the recess 34 inserted so that the impeller wheel 20 about the ball bearing 32 on the wave 38 is rotatably supported about the axis A. Furthermore, the supply lines are passed through 44 through the bearing bush 54 and introducing the in 3 right end of the wave 38 into the bearing bush 54 the motor housing 48 on the ring ledge 28 put on so that the in 3 left area of the motor housing 48 the radially outer area of the ring projection 28 embraces. The ring projection 28 and the motor housing 48 are coordinated in diameter in the interacting areas. After touchdown, the impeller wheel 20 on its ring ledge 28 with the motor housing 48 , sealingly connected, for example by gluing or the like.

It should be noted that for the axial bracing of the bearing 32 between the left end of the shaft 38 and the elastomeric spring element 36 a ball 56 is inserted into a cylindrical recess 58 in the wave 38 intervenes. The bullet 46 ensures together with the elastomeric spring element 36 for making the wave 38 towards the 1 - 3 is biased to the right and thus on the impeller wheel 20 acting axial loads on the bearing 32 free of play on the shaft 38 can be transferred.

On the pump motor assembled in this way 18 then become a sealing ring in an area close to the impeller 60 and an external threaded ring 62 put on, as in 2 shown. Furthermore, the reduced diameter area 52 of the motor housing 48 a sealing bush 64 placed. The sealing bush 64 is, as shown in particular from the enlarged view 1 can be seen on their the second housing part 16 Provide facing sides with thread formations. Furthermore, the wave 38 facing surface of the threaded bush 64 also formed a thread formation. The mode of operation of these thread formations will be discussed in detail later.

If you turn to the housing 12 to, you can tell 2 that the first housing part 14 an axial opening 66 has, through which fluid can flow. It extends from this axial opening 66 rounded radially outward, where there is a tub running around the axis A in the circumferential direction 68 forms that in a flange 70 expires. The tub 68 has a round contour with a constantly changing inner radius r in the circumferential direction.

The second housing part 16 is also cup-shaped and has a stepped interior 72 on. There are cooling fins on its outer surface 74 provided that the effective surface for heat dissipation in the electric motor 18 enlarge the receiving area. The cooling fins 74 run in a circumferential direction around the axis A. 76 from, which in turn in a flange 78 expires. The tub too 76 has a round contour with a continuously changing inner radius p in the circumferential direction. There is an outlet connection in the area of the largest inner radius p 80 on the tub 76 intended.

For further assembly of the pump 10 the electric motor with its shaft 38 , as in 2 shown in the tiered interior 72 of the second housing part 16 introduced so the wave 38 in the smallest diameter part of the cavity 72 and the sealing bush 64 in the area of the cavity 72 engages with the next largest diameter. The first housing part then becomes the impeller wheel side 14 with its flange 70 to the flange 78 of the housing part 16 created and with this over Connection means, such as screws, rivets, or connected by gluing. This defines the two tubs 68 and 76 a channel extending in the circumferential direction around the axis A. 82 , wherein the tub diameters r and p are chosen such that the cross-sectional area of the channel 82 in the direction of rotation of the impeller wheel 20 to the outlet nozzle 80 steadily enlarged. This enables the impeller wheel to be used during operation 20 in the channel 82 delivered fluid to the outlet nozzle 80 is pressed down.

After assembling the pump in this way 10 has the shape as in 1 shown in longitudinal section. The following features are particularly noteworthy in this construction. The components of the electric motor 18 , namely magnetic ring 50 as well as sheet metal package 40 and windings 42 , are inside the pot-like motor housing 48 recorded and through the tight connection of the motor housing 48 and impeller wheel 20 encapsulated in relation to the environment. With this design of the electric motor 18 it is possible between the inner circumferential surface of the magnetic ring 50 and the outer peripheral surface of the laminated core 40 to provide a very narrow magnetic gap S, whereby the magnetic induction B increases in the gap and ultimately the motor efficiency can be increased. This design of the pump electric motor also offers 18 some advantages over the pump described above according to the DE 199 43 862 A1 , because due to the elimination of the generally metallic containment shell from the magnetic motor air gap, which is possible due to the invention, very small air gaps can be realized which bring about a high motor efficiency. In addition, the eddy current losses occurring there are minimized. Furthermore, protective armor caps around the magnets, which also require a large amount of space, are unnecessary insofar as the magnetic ring rotates inside the return cup and is therefore less sensitive to the centrifugal forces acting on it.

In the in the 1 to 3 The embodiment shown is the motor housing 48 Made of a soft magnetic material so that it is the magnetic yoke to the magnetic ring 50 can form.

The second housing part 16 takes the pump motor 18 with a likewise relatively thin gap R between the cavity 72 delimiting inner surface and the outer surface of the motor housing 48 on. Around this gap R in relation to the areas of the pump near the impeller wheel intended for fluid delivery 10 to seal, are the sealing ring 60 and the external threaded ring 62 intended. The sealing ring 60 provides a static seal by attaching both to the motor housing 48 as well as on the inner surface of the second housing part 16 is applied. The external threaded ring 62 only has a dynamic sealing effect, namely in such a way that when the motor housing rotates, the thread formation formed on it 48 and thus the external thread ring 62 Flow effects arise in the valleys of the thread formation, which convey the fluid contained therein from the gap R to the impeller wheel. In the static case, ie when the motor housing is at a standstill 48 relative to the pump housing 12 the external threaded ring unfolds 62 hardly any sealing effect since it has the surface section of the second housing part opposite it 16 not touched.

Despite the sealing ring 60 and external threaded ring 62 occurs when fluid is conveyed via the impeller wheel 20 due to relatively high fluid pressures in the channel rotating around the axis A. 82 to leakage fluid flowing into the gap R and filling it. This leakage fluid has the advantage that it fluidically dampens engine noise and that it leads to rapid thermal transfer from within the engine 18 generated heat to the cooling fins 74 contributes. However, it should be prevented that the leakage fluid that has penetrated into the gap R via the slide bearing 54 in the encapsulated interior of the motor housing 48 forced out. For this purpose, unfolds in dynamic operation, ie when there is relative rotation between the motor housing 18 - And the associated sealing bush 64 - And second housing part 16 who have favourited Seal Bushing 64 with their return thread formations sealing effect. The thread formations on the sealing bush 64 are designed in such a way that, when rotating in the valleys of the thread formations, flow effects occur which cause the leakage fluid located there to form a leakage channel running in the circumferential direction 84 convey, which then via a drain hole 86 and a ball valve 88 is connected to the environment to discharge excess leakage fluid. If the leakage should become quantitatively too large, a return (not shown in detail) to the cooling circuit can be provided.

The related to 1 to 3 The pump described can thus convey fluid from the axial opening 66 through the channels 22 of the impeller wheel 20 to the perimeter channel 82 and out of this over the outlet nozzle 80 prevent large amounts of leakage fluid from entering the gap R and, via this, into the interior of the pot-like motor housing 48 penetrate. This is particularly advantageous if, on the one hand, there is an undesired contact between the motor component magnetic ring 50 , Sheet package 40 and windings 42 - Is to be prevented, for example in a case in which the pump is also used to convey aggressive media that could attack or even damage the motor components. Even sensitive media, in which there is contact between Motor Com Components and fluid to avoid contamination can be pumped with such an encapsulated pump.

Furthermore, with the in 1 Pump arrangement shown can also be avoided undesirable "splash losses" that occur, for example, in pumps in which the rotating motor components are located directly in the fluid to be pumped and rotate against its fluidic resistance.

The in 1 Pump structure shown has the further advantage that the electric motor 18 due to its design as an external rotor motor, it can be made compact, and therefore the pump as a whole 10 Space taken up can be greatly reduced compared to conventional pumps. This is also due to the fact that the structure shown has a reduced number of parts, in particular because the impeller wheel 20 at the same time in combination with the pot-shaped or bottle-shaped motor housing 48 is used for encapsulation, also because with the ball bearing 32 and the small-sized plain bearing 54 a small-sized bearing arrangement is used, and also because the cup-shaped motor housing 48 is simultaneously designed as a magnetic yoke for providing a magnetic yoke.

Further exemplary embodiments of the present invention are to be described below. It should be pointed out that the same reference numerals are used for components of the same type or having the same function as in the description of the first exemplary embodiment according to FIGS 1 to 3 happen, but supplemented with lowercase letters to differentiate the individual embodiments.

In 4 is shown a second embodiment of the pump according to the invention, generally with the reference numeral 10a is designated. The embodiment according to 4 differs from the exemplary embodiment according to 1 to 3 especially in the following points: The impeller wheel 20a is in its radially outer region with an elongated edge in the axial direction 90a Mistake. On the face of the edge orthogonal to axis A. 90a it abuts with a corresponding end face of the motor housing shortened in the axial direction compared to the first embodiment 48a together. The two end faces are glued or welded together, in any case sealed. The engine case 48a just like the impeller wheel 20a are made of a lightweight plastic material or aluminum, which are very sensitive to corrosion, light and easy to work with and have good heat transfer properties. This allows the combination of the motor housing 48a and impeller wheel 20a no longer as a magnetic inference for the magnetic ring 50a serve so that between the components motor housing 48a as well as edge 90a of the impeller wheel 20a and the magnetic ring 50a additionally a ring element 92a is provided, which ensures a magnetic return.

Furthermore, the impeller wheel 20a a thread formation on its radially outer region 94a on, which acts as a dynamic seal after a return thread seal and the penetration of fluid to be pumped into the gap R between the second housing part 16a and the engine housing components 48a or edge 90a limits. By this measure, in comparison to the first embodiment according to 1 to 3 the sealing ring 60 and the external threaded ring 62 be omitted. Likewise, are at the impeller wheel remote area of the motor housing 48a thread formations 96a provided, which is analogous to the sealing bush 64 according to the first embodiment 1 to 3 are oriented and together with the leakage channel 84a , the drain hole 86a and the ball valve 88a ensure that leakage fluid is removed from the gap R. Another difference from the first exemplary embodiment is in the second exemplary embodiment according to

4 the plain bearing bush 54 through a spherical ring seal 98a replaced. The dome ring 98a takes on the one hand bearing function, but on the other hand also sealing function, so that leakage fluid penetrates to the motor components magnetic ring 50a , Bleckpaket 40a and windings 42a can be prevented.

5 shows a third embodiment of the pump according to the invention, generally with the reference numeral 10b is designated. This embodiment results from a combination of the first two exemplary embodiments according to FIGS 1 to 4 of the present invention. It is on the outer circumference of the impeller wheel 20b again a thread formation 94b provided that ensures a dynamic sealing of the gap R. The engine case 48b is according to the motor housing 48 out 1 Made of soft magnetic material and thus ensures a magnetic inference to the magnetic ring 50b , The engine case 48b is from the impeller wheel 20b encompassed and included in this. Otherwise, the structure according to the third embodiment corresponds to 5 essentially according to the structure of the first embodiment 1 ,

6 shows a fourth embodiment of the pump according to the invention, generally with the reference numeral 10c is designated. This fourth embodiment is discussed below its differences from that with respect to 4 Described above described second embodiment.

The essential difference of the fourth embodiment according to 6 according to the second embodiment 4 is that the ball bearing 32a through a plain bearing 100c was replaced by a ring arrangement 102c and 104c on the wave 38c is axially secured. By using the plain bearing 100c On the one hand, a ball bearing, which is more expensive to buy, can be replaced, on the other hand, this allows installation space in the area of the pump near the impeller 10c be saved. Another difference of the fourth embodiment according to 6 according to the second embodiment 4 is that in the gap R between the pump housing 48c and the second housing part 16c a labyrinth seal is formed. The labyrinth seal is realized in that ring projections 106c and 108c in corresponding ring recesses 110c and 112c intervention. The gap R thus has a labyrinthine course, which makes it difficult for leakage fluid to pass through. In addition, the fourth embodiment according to 6 in the area of the motor housing end remote from the impeller 48c a sealing bush 64c with thread formations that act as a thread return seal leakage fluid through the drain hole 86c derive, as already according to the first embodiment 1 - 3 has been described.

7 shows a fifth embodiment of the pump according to the invention, generally with the reference numeral 10d is designated. This fifth embodiment is similar in its construction in the area near the impeller wheel and in the design of the pump motor 18d essentially according to the second embodiment 4 , The fifth embodiment has one as compared to the second embodiment 4 modified bearing and sealing arrangement remote from the impeller. The engine case 48d is because of his approach 52d in a plain bearing bush or a sealing bush 114d stored, this plain bearing bush 114d , in particular a ceramic bushing, into the second housing part 16d screwed threaded bolt 116d is rotatably fixed. A calotte seal can also be used in this area 98d be provided via a threaded bushing 64d in the motor housing 48d is held. The calotte seal 98d takes over sealing and storage function. The sealing bush 64d is threaded to provide dynamic leakage fluid to the drain hole 86d and to promote this to the environment.

8th shows a sixth embodiment of the pump according to the invention, generally with 10e is designated. This sixth embodiment of the invention is in its impeller wheel 20e near area essentially as in the first embodiment of FIG 1 formed, with only a sealing ring 60e is provided to prevent leakage fluid from penetrating into the gap R between the second housing part 16e and the motor housing 48e counteract. In the area far from the impeller is on the plain bearing bush 54e an o-ring 118e provided the penetration of leakage fluid to the bearing bush 54e should prevent. The main peculiarity of the in 8th The sixth embodiment shown compared to the previously described embodiments is that it is provided with a sensor system for detecting the engine rotation. This sensor system includes on the motor housing 48e attached magnetic elements 120e that deal with the motor housing 48e rotate according to one motor rotation. Corresponding to the magnetic elements 120e are sensors 122e on the second housing part 16e of the pump housing 12e intended. By means of the magnetic elements 120e and the sensors 122e there is a relative rotation between the motor housing 48e and pump housing 12e to capture. In other words, the sensors, including the magnetic elements 120e and the sensors 122e , determine the current state of rotation of the pump, ie the speed, so that the pump 10e can easily be integrated into a regulation. The signals recorded via the sensors are fed via leads 124e led to an evaluation electronics, not shown.

9 and 10 show a seventh embodiment of the present invention, which is essentially in accordance with the first embodiment in terms of the design of the motor, the precautions for sealing and in terms of storage 1 to 3 oriented. The difference, however, is that that's about the opening 66f axially inflowing fluid the pump again in the axial direction via an outflow connection 126f leaves, in contrast to the exemplary embodiments described above, in which the fluid essentially flowed out in the radial direction - in 1 over the outlet nozzle 80 , The axial discharge of the fluid is achieved in that, as in 10 shown radially around the second housing part 16f around a variety of semi-cylindrical channels 128f are formed by a now also cup-shaped first housing part 14f are sealed radially outwards. On the in 9 on the right side there is a cover 130f intended.

The exemplary embodiments described above show various possibilities of how simple, compact pumps of a small size can be obtained with an encapsulated electric motor with high motor efficiency, which pumps are independent of the sensitivity and properties of the fluid to be pumped can be used.

The disclosed in the foregoing description, the figures and the claims Characteristics can both individually and in any combination for implementation of the invention in the various configurations of importance his.

Claims (24)

Electric motor ( 18 ) for use as a pump motor, with one with at least one winding ( 42 ) provided stator ( 40 ), the stator ( 40 ) encompassing outer rotor ( 50 ) and a non-rotatable with the outer rotor ( 50 ) connected motor housing ( 48 ) with a pump wheel ( 20 ) is connected, the motor housing ( 48 ) with the outer rotor ( 50 ) via a bearing arrangement ( 32 . 54 ) rotatable on the stator ( 40 ) holding, fixed shaft ( 38 ) is stored, the bearing arrangement ( 32 . 54 ) a first bearing near the pump wheel ( 32 ) and a second bearing remote from the pump wheel ( 54 ) and the motor housing ( 48 ) sealing with the pump wheel ( 20 ) is connected and together with the pump wheel ( 20 ) the stator ( 40 ) and the outer rotor ( 50 ) sealed encapsulates. Electric motor ( 18 ) according to claim 1, characterized in that the motor housing ( 48 ) sealing on a ring projection ( 28 ) of the pump wheel ( 20 ) is attached. Electric motor ( 18 ) according to claim 1, characterized in that the motor housing ( 48 ) sealing in the pump wheel ( 20 ) is included. Electric motor ( 18 ) according to one of claims 1 to 3, characterized in that the motor housing ( 48 ) is made of a soft magnetic material. Electric motor ( 18a ) according to one of claims 1 to 3, characterized in that the motor housing ( 48a ) is made of a non-magnetic material and that between the outer rotor ( 50a ) and the motor housing ( 48a ) a soft magnetic yoke ( 92a ) is provided. Electric motor ( 18c ) according to one of claims 1 to 5, characterized in that the first bearing ( 100c ) is designed as a plain bearing, which on the shaft ( 38c ) is axially secured. Electric motor ( 18 ) according to one of claims 1 to 5, characterized in that the first bearing ( 32 ) as roller bearings, especially as ball bearings ( 32 ), is trained. Electric motor ( 18 ) according to one of claims 1 to 7, characterized in that the first bearing ( 32 ) in one in the impeller ( 20 ) trained inventory ( 30 ) is included. Electric motor ( 18 ) according to one of claims 1 to 8, characterized in that the bearing arrangement, in particular in the region of the first bearing ( 32 ), is axially clamped. Electric motor ( 18 ) according to claim 10, characterized in that for the axial bracing of the bearing arrangement between the shaft ( 38 ) and the impeller ( 20 ) a spring element biased in the axial direction (A) ( 36 ), especially an elastomer spring element ( 36 ), and one on the spring element ( 36 attacking bullet 56 ) are arranged. Electric motor ( 18 ) according to one of claims 1 to 10, characterized in that the second bearing ( 54 ) is designed as a plain bearing, in particular as a compact sintered bearing, plastic bearing, ceramic bearing or spherical bearing. Electric motor ( 18 ) according to one of claims 1 to 11, characterized in that the second bearing ( 54 ) in one in the motor housing ( 48 ) trained inventory ( 52 ) is included. Electric motor ( 18c ) according to one of claims 1 to 12, characterized in that between the shaft ( 38e ) and the motor housing ( 48e ) in the area of the second warehouse ( 54e ) at least one radial seal ( 64e ), in particular at least one mechanical seal or at least one O-ring ( 118e ), is provided. Electric motor ( 18a ) according to one of claims 1 to 13, characterized in that between the shaft ( 38a ) and the motor housing ( 48a ) at least one resilient axial seal in the area of the second bearing ( 98a ) is provided. Electric motor ( 18 ) according to one of claims 1 to 14, characterized in that between the shaft ( 38 ) and the motor housing ( 48 ) in the area of the second warehouse ( 54 ) at least one return thread seal ( 64 ) is provided, with the return thread either on the shaft ( 38 ) or on the motor housing ( 48 ) or on a sealing bush ( 64 ) between wave ( 38 ) and motor housing ( 48 ) is trained. Electric motor ( 18 ) according to one of claims 1 to 15, characterized in that the shaft ( 38 ) with a hole ( 46 ) for receiving supply lines ( 44 ) to the stator ( 40 ) is provided. Pump ( 10 ) for conveying fluids, carried out with an electric motor ( 18 ) according to one of claims 1 to 16, wherein the pump ( 10 ) the electric motor ( 18 ) receiving pump housing ( 12 ) with an inflow ( 66 ) and a sequence ( 80 ) for supplying and discharging the fluid. Pump ( 10 ) according to claim 17, characterized in that between the pump housing ( 12 ) and the motor housing ( 48 ) a thin gap (R) is provided. Pump ( 10 ) according to claim 18, characterized in that in a region close to the pump wheel on the pump housing ( 12 ) or / and on the motor housing ( 20 . 48 ) for sealing the gap (R) a gap seal, especially a sealing ring ( 60 ) or / and a return thread seal ( 62 ), is provided. Pump ( 10 ) according to claim 18 or 19, characterized in that in a region away from the pump wheel of the motor housing ( 48 ) near the second camp ( 54 ) a further gap seal is provided for sealing the gap (R). Pump ( 10 ) according to one of claims 18 to 20, characterized in that the further gap seal is a labyrinth seal ( 106c . 108c . 110c . 112c ) or / and a ring seal, in particular an O-ring, or / and a thread return seal on the sealing bush ( 64 ) includes. Pump ( 10 ) according to claim 21, characterized in that the return thread seal is formed with a thread pitch oriented in the axial and / or in the radial direction. Pump ( 10 ) according to one of claims 18 to 22, characterized in that the gap (R) with an overflow ( 84 . 86 . 88 ) is connected to discharge or return of excess fluid. Pump ( 10 ) according to one of claims 17 to 23, characterized in that it is designed as an axial pump, in which the fluid to be delivered is discharged in the axial direction.