DE102012200803B4 - Wet rotor - Google Patents

Abstract

A wet rotor pump having an axial flow motor comprising a stator (110, 112, 114), a containment shell (116) and a rotor (122, 124), wherein the stator and containment shell are in a dry area and the rotor is coupled to an impeller (128) a wet zone, having an inlet conduit (134, 156) for a fluid (108) to be delivered through the impeller, and a bearing (154, 156) for the impeller, the bearing being disposed at an end of the inlet conduit, and the bearing supports the impeller with an axial degree of freedom, the inlet conduit extending axially through the stator, the containment shell and the bearing, the stator being formed by an annular stator tooth receptacle (112) along the circumference of which stator teeth (114) are secured wherein each of the stator teeth (114) has an axially extending receiving area (118) for a coil.

Description

The invention relates to a wet-running pump for conveying a fluid, in particular a liquid.

Out DE 10 2005 015 213 A1 is a wet runner known. The wet-running pump has a rotor connected to a pump wheel, which is arranged in a wet region through which a pumped fluid flows. The wet area is separated from a dry area where the stator is located. The demarcation of the wet area of the dry area is made by a circuit board whose electrical lines form the stator, so that the circuit board simultaneously forms a split pot. Other embodiments of wet runner pumps are in WO 2006/137496 A1 . WO 00/37804 A1 . EP 1 130 741 A2 . US 5,332,374 A. and US 2002/0166 520 A1 described.

Out DE 102 03 778 A1 is an electrically driven pump is known which has a trained as a disc rotor electric drive motor. The magnetic ring of the drive motor is arranged in a region through which fluid flows.

From the DE 690 13 761 T2 Furthermore, a magnetic pump with a permanent magnet as a magnetic means is known, wherein the permanent magnet embedded in the impeller of the pump and is disc-shaped. Furthermore, the permanent magnet is oriented at right angles to the axis of the impeller. Moreover, the outer diameter of the bearing is smaller than the inner diameter of the permanent magnet.

The JP 2011-106 323 A further describes a motor pump having an impeller having a plurality of embedded permanent magnets, a pump housing including the impeller, a stator of the motor including a plurality of stator coils, a motor housing including the motor, and a dynamic pressure bearing which carries the impeller.

Furthermore, axial flow motors per se are known from the prior art. In an axial flow motor, the magnetic flux in the air gap of the motor in the axial direction, for example, compare DE 100 53 400 A1 or DE 16 13 626 A ,

The invention is the object of the invention to provide an improved wet runner pump.

The object underlying the invention is achieved with the features of claim 1. Embodiments of the invention are indicated in the dependent claims.

According to embodiments of the invention, a wet-running pump is provided in which an inlet line for the fluid passes through the stator, the containment shell and the bearing for the impeller. Such a geometry is made possible by the design of the motor as Axialflussmotor and has the particular advantage of a particularly compact design of the wet-running pump, that is, a low profile, combined with a high power density. In this case, the stator has an annular Statorzahnaufnahme on which stator teeth are arranged, wherein each of the stator teeth has an axially extending receiving area for a coil. The stator teeth can be attached, for example, by gluing to the Statorzahnaufnahme.

Embodiments of the invention are also particularly advantageous because the bearing simultaneously acts as a seal at the transition between the suction and the pressure side of the wet-running pump. Due to the relatively small gap mass and the small tolerances of the bearing, only slight leakage losses occur.

According to one embodiment of the invention, the inlet of the fluid is through a central opening of the containment shell. In particular, the containment shell can form an inlet connection.

According to one embodiment of the invention, the stator is toroidal.

According to one embodiment of the invention, each of the stator teeth has an enlarged cross section at the air gap side end. This has the advantage that the magnetic field in a larger area within the air gap is approximately homogeneous and so completely wraps around the narrower in the radial direction rotor magnets, whereby the self-centering of the impeller is supported, thereby supporting the self-centering of the impeller. By "air gap" is meant here the distance between the ends of the stator teeth and the rotor, even if there is no or not only air in this gap, such. As the fluid.

According to one embodiment of the invention, the power electronics, which serves to drive the coils of the stator, are arranged within the space circumscribed by the stator and the can, for example on an annular printed circuit board. As a result, the height of the wet runner pump can be further reduced.

According to one embodiment of the invention, the containment shell is formed by an annular disc which projects into the air gap between the stator and the rotor and which defines the dry region of the wet-running pump from the wet region separates. The annular disc has a central opening on which the inlet nozzle is arranged, which extends through the center of the stator. At the disk-side end portion of the inlet nozzle, the bearing for the impeller is arranged, through which the fluid flows into the wet area after it has passed through the drying area through the inlet line. The disc and the inlet nozzle may be integrally formed, in particular as a plastic injection molded part. In particular, the containment can be formed as a plastic part (eg made of PPS / GFK / CFK) or as a non-magnetic metallic part.

According to one embodiment of the invention, the bearing is designed as a sliding bearing, wherein a bearing bush of the sliding bearing is arranged on the disk-side end portion of the inlet nozzle and a sliding bearing element of the sliding bearing is attached to the impeller. A sliding surface of the sliding bearing element engages in the bearing bush, so that a radial bearing is provided. For an additional one-sided axial bearing for receiving the magnetic attraction of the stator, which acts on the impeller via the rotor, a further sliding surface may be provided on the bearing.

Embodiments of the invention are particularly advantageous since a magnetic attraction force is exerted on the stator in the direction of the stator by the axial flux motor, so that the impeller only needs to be mounted on one side. This simplifies the construction and further reduces the required height of the wet runner pump.

According to one embodiment of the invention, the sliding bearing element in the radial direction through holes, such as about 1 mm large lubrication holes, which serve to direct a very small part of the volume flow of the fluid through the bearing, so as to additionally lubricate.

According to one embodiment of the invention, the bearing is coated with a combination of diamond-like carbon and silicon carbide (SiC) to make the bearing particularly durable.

• – Samarium-Cobalt kann bei hohen Temperaturen eingesetzt werden, ohne dass die Remanenz der Magnetisierung leidet. Aufgrund dessen kann das Fluid eine Temperatur von zum Beispiel bis zu 200°C haben.
• – Samarium-Cobalt besitzt exzellente Korrosionseigenschaften und kann mit einem einfachen oder ohne Korrosionsschutz direkt dem Fluid ausgesetzt werden.
• – Da eine Kapselung zum Beispiel in Edelstahl von Samarium-Cobalt zum Korrosionsschutz nicht erforderlich ist, kann das magnetische Material am äußersten Rand der Peripherie des Impellers bzw. der Antriebsscheibe angeordnet sein, sodass das permanentmagnetische Material mit einem maximalen Radius positioniert werden kann.

According to one embodiment of the invention, the rotor is formed by a permanent magnetic material, namely samarium cobalt (SmCo). This is advantageous in several ways:

• - Samarium cobalt can be used at high temperatures without the remanence of the magnetization suffers. Due to this, the fluid may have a temperature of, for example, up to 200 ° C.
• - Samarium cobalt has excellent corrosion properties and can be exposed directly to the fluid with a simple or no corrosion protection.
• For example, since samarium cobalt stainless steel encapsulation is not required for corrosion protection, the magnetic material may be located at the very edge of the impeller or drive disk periphery so that the permanent magnetic material can be positioned with a maximum radius.

The permanent magnetic material forming the rotor can be arranged in the form of a plurality of individual flat permanent magnets on the periphery of the impeller or in the form of a single magnetic ring with multipolar magnetization. In particular, the magnets or the magnetic ring can be attached directly to the periphery of the impeller or via a drive pulley on the impeller.

In the following, embodiments of the invention will be explained in more detail with reference to the drawings. Show it:

1 an exploded view of a wet runner pump according to the invention,

2a a side view of a single stator tooth,

2 B a front view of the stator tooth according to 2a .

2c a perspective view of the stator tooth according to 2a .

3a a top view of the stator,

3b a sectional view of the stator,

4a a plan view of an embodiment of the split pot,

4b a sectional view of the containment shell according to 4a .

4c a sectional view of the bearing bush of the split pot according to 4a .

4d a sectional view of an embodiment of the sliding bearing element of the impeller,

5a a plan view of an embodiment of the rotor,

5b a sectional view of the rotor according to 5a .

6 a sectional view of an embodiment of the drive pulley,

7 a sectional view of an embodiment of the impeller,

8th a sectional view of the wet-running pump according to 1 in the assembled state.

In the following, elements of the following embodiments, which correspond or are identical to one another, are each marked with the same reference numerals.

The 1 shows an exploded view of an embodiment of a wet-running pump according to the invention 100 , The wet runner pump 100 has an engine cover 102 which has a circular front 104 having. In the center of the front 104 there is an opening 106 , which for the inflow of a fluid 108 is provided.

The engine cover 102 serves to cover a stator 110 , The stator 110 has a stator tooth receptacle 112 , which is annular and on the stator teeth 114 are arranged in a circle. Each of the stator teeth has a receiving area 118 on which a spool is wound up (see 2 and 3 ).

The different coils of the stator teeth 114 are with power electronics 120 electrically connected, which serves to drive the coils.

The rotor of the Axialflussmotors is formed in the embodiment considered here by a permanent magnetic material, which here in the form of individual permanent magnets 122 on a ring 124 is arranged (see 5 ).

The permanent magnets 122 have a magnetization in the axial direction, so that the magnetic flux between the ends 126 the stator teeth 114 and the permanent magnet 122 over an air gap, which is between the ends 126 and the permanent magnet 122 exists, also in the axial direction of the wet-running pump 100 extends. Due to this, a magnetic attraction force generated by the stator becomes 110 on the permanent magnets 122 , and on an impeller 128 the wet runner pump 100 exercised.

Into the air gap between the ends 126 the stator teeth 114 and the permanent magnet 122 sticks out a slice 130 a containment shell 116 , The disc 130 has recesses 132 used to receive the ends of the stator teeth 114 serve (compare 4a . 4b ). The braces between the recesses increase the mechanical stability of the engine structure and allow the smallest possible material thickness and thus a minimum air gap. For example, the wall thickness of the split pot 116 in the recesses 132 between 0.7 mm and 0.2 mm. Such a small wall thickness reduces the air gap, which in turn increases the efficiency and performance while maintaining a certain amount of rare earth magnets. As a result, the mechanical stability of the engine structure is improved.

The disc 130 has an axial opening on which an inlet port 134 is arranged.

The inlet nozzle 134 protrudes in the assembled state of the wet runner pump 100 (see 8th ) through the stator 110 and the opening 106 the engine cover 102 through, so over the inlet pipe 134 the fluid 108 can flow in.

Through the containment shell 116 and the stator 110 is a space circumscribed in which the power electronics 120 can be arranged, such as on an annular board 136 whose outer radius through the recesses 132 and its inner radius through the wall of the inlet nozzle 134 is limited, this board 136 can the various electrical and electronic components to realize the power electronics 120 wear. As these are in the dry area of the wet runner pump 100 is arranged, is a special encapsulation of the power electronics 120 not necessarily required.

At the inlet pipe 134 is at an axial distance from the disk 130 a mounting area 138 arranged on which the engine cover 102 For example, is fastened by screw. The stator 110 is then between the engine cover 102 and the disc 130 held, with the ends 126 the stator teeth 114 in the recesses 132 stand and there z. B. are held positively.

The attachment area 138 may, for example, be annular, as in the 1 shown, and internal thread for the formation of screw to attach the engine cover 102 have, which corresponding holes 140 to carry out the screws. At the same time, the tube-shaped continuation of the can with upwardly disk-shaped form also serves to center the stator return ring, ie the stator tooth receptacle 112 The wet runner pump has a first housing half 142 and a second housing half 144 through which the housing of the wet-running pump 100 is formed. The housing half 142 has an opening in its center 146 , which at the air gap-side end of the inlet nozzle 134 connects so that the fluid 108 from the inlet nozzle 134 through the opening 146 flows. The disc 130 is on the outside of the case half 142 attached, such as through Screw connections on an annular mounting area 148 the housing half 142 , The inlet line is thus in the embodiment considered here through the inlet port 134 arranged with the arranged at its air gap end end bearing bush 156 educated.

The impeller 128 is located between these housing halves 142 and 144 , At the impeller 128 the rotor is formed by the ring 124 with the permanent magnets 122 via a drive pulley 150 with the impeller 128 , for example by screws 153 , connected is. According to an alternative embodiment, the permanent magnets 122 also directly on the impeller 128 be arranged. Furthermore, the permanent magnets 122 between the ring 124 and the drive pulley 150 be arranged.

The impeller has an extension 152 for receiving a sliding bearing element 154 , which together with a bearing bush 156 a plain bearing for radial storage of the impeller 128 forms (compare 4c and 4d ). The warehouse stores the impeller 120 with an axial degree of freedom, because of the impeller 128 over the permanent magnets 122 a magnetic attraction in the axial direction of the stator 110 is applied, so that the axial position of the impeller 128 is also determined. That through the sliding bearing element 154 and the bearing bush 156 formed bearing may be formed so that it is formed on one side in the axial direction as an abutment for receiving the magnetic attraction force (see this 4c and 4d ).

This magnetic attraction of the stator 110 also has - under rotation - a self-centering effect on the impeller 128 , which reduces the stress on the plain bearing.

The two housing halves 142 and 144 be through screws or glue 148 connected with each other.

This way becomes an outlet 160 for the fluid 108 educated.

Embodiments of the invention are particularly advantageous because the fluid 108 flows stator side, through the stator through. Due to the Axialflussmotors further only one-sided storage of the impeller is required without any rotor shaft, which allows a total of a particularly compact design with high power density.

The 2a shows a front view of one of the stator teeth 126 according to the embodiment according to 1 , The recording area 118 of the stator tooth 126 serves to accommodate multiple windings of a coil 162 that of the power electronics 120 the board 136 is controlled.

The recording area 118 of the stator tooth 114 becomes the air gap side through the end 126 of the stator tooth 114 completed, which is one compared to the recording area 118 has enlarged cross-section. This enlarged cross-section has the advantage that the magnetic field in the air gap is correspondingly expanded and is approximately homogeneous in a larger spatial area. This will cause the self-centering of the impeller 128 (see 1 ) supports, since the permanent magnets 122 of the rotor have a smaller width in the radial direction than the stator flux width.

The 2a shows an example of one of the permanent magnets 122 as it does on the impeller relative to the stator tooth 114 angeordent is. In the radial direction is the permanent magnet 122 shorter than the extension of the end 126 of the stator tooth 114 in the radial direction, so that the stator tooth via the permanent magnet 122 protrudes. For example, the permanent magnet 122 in the middle of the reception area 118 positioned.

The stator tooth 114 has a slot-shaped recess in its upper area 162 , which are used to fasten the stator tooth 114 at the Statorzahnaufnahme 112 serves (compare 3 ).

The 2 B shows the stator tooth 114 in a front view and the 2c in a perspective view.

The 3a shows a plan view of the stator 110 with the annular Statorzahnaufnahme 112 having in its center an opening through which the inlet nozzle 134 passes through (see 1 ). At the periphery of the Statorzahnaufnahme 112 are the stator teeth 114 with their recesses 162 attached. This can be done by the recess 162 and / or the Statorzahnaufnahme 112 serve as adhesive surfaces to the stator tooth 114 with its recess 162 to the edge of the Statorzahnaufnahme 112 to stick. The 3b shows a corresponding sectional view.

The 4a shows a plan view of the containment shell 116 through its inlet nozzle 134 the fluid can flow.

The 4b shows a sectional view of the containment shell 116 , Like in the 4b shown is the air gap side end of the inlet nozzle 134 for receiving a bearing bush 156 trained, which in the 4c is shown. This is at the end of the inlet nozzle 134 formed an inner radius R, in which the bearing bush 156 for example, using a press fit and can fix.

At the extension 152 the impeller 128 (see 1 ) is a sliding bearing element 154 attached, which is the counterpart to the bearing bush 156 forms. The sliding bearing element 154 is annular and has an end portion 164 , whose outer diameter is reduced, thereby thereby outside of the sliding bearing element 154 a circumferential edge 166 is formed.

The bearing bush 156 So take the end section 164 of the sliding bearing element 154 on, with the inside of the bearing bush 156 and the outside of the end portion 164 of the sliding bearing element 154 form the sliding surfaces of the sliding bearing. This will be the impeller 128 radially mounted. The axial degree of freedom of the impeller 128 is by the circumferential edge 166 limited.

Will namely the impeller 128 during operation of the axial motor in the direction of the stator 110 attracted by the occurring magnetic forces, so hits the edge 166 on the front of the bearing bush 156 , whereby an abutment for receiving this magnetic attraction force is formed. So, anyway, the impeller 128 with an axial degree of freedom, that is axial play, in the containment shell 116 is stored, yet due to the magnetic attraction, the axial position of the impeller 128 defined during operation of the Axialflussmotors.

Preferably, at least one of the sliding surfaces of the sliding bearing is coated with Diamond-Like-Carbon (DLC) and silicon carbide (SiC) or a combination of DLC and SiC to increase the life of the bearing.

According to embodiments of the invention, it is particularly advantageous that the fluid 108 is sucked through the camp, which in turn contributes to the compact design of the wet-running pump. The plain bearing can have a very narrow gap, which is for example about 0.01 mm to 0.03 mm and therefore at the same time seals very well.

According to one embodiment of the invention, the sliding bearing element 154 have one or more radial openings, such as about 1 mm large lubrication holes. Through these openings, a very small part of the volume flow of the fluid 118 directed between the sliding surfaces of the bearing to lubricate this addition. Preferably, this is at least one opening in the end portion 164 of the sliding bearing element 154 arranged and directed to the center.

• – Samarium-Cobalt kann bei relativ hohen Temperaturen eingesetzt werden, ohne dass die Remanenz leidet; insbesondere kann das Fluid 108 eine Temperatur von bis zu 200°C haben.
• – Aufgrund seiner exzellenten Korrosionseigenschaften kann Samarium-Cobalt ohne Beschichtung und ohne Kapselung dem Fluid 108 ausgesetzt werden.
• – Da keine Kapselung der Permanentmagnete 122 erforderlich ist, können diese mit einem maximalen Abstand von der Rotationsachse positioniert werden, sodass sich ein maximales Drehmoment und eine maximale Motorleistung bei einer gegebenen Menge von magnetischem Werkstoff ergibt.

The 5 shows a plan view of the rotor with the permanent magnets 122 on the ring 124 are arranged. Preferably, the permanent magnets exist 122 made of samarium cobalt, which has several advantages:

• - Samarium cobalt can be used at relatively high temperatures without the remanence suffers; In particular, the fluid 108 have a temperature of up to 200 ° C.
• - Due to its excellent corrosion properties, samarium cobalt can be applied to the fluid without coating or encapsulation 108 get abandoned.
• - Since no encapsulation of the permanent magnets 122 are required, they can be positioned with a maximum distance from the axis of rotation, so that a maximum torque and a maximum motor power results for a given amount of magnetic material.

Alternatively, other materials for the permanent magnets 122 be used, such as neodymium-iron-boron.

The 6 shows the drive pulley 150 in cross section. The drive pulley 150 serves the rotor, that is the ring 124 with the permanent magnets 122 , with the impeller 128 mechanically connect, with the extension 152 the impeller 128 through the drive pulley 150 protrudes, as in the 1 shown.

The 7 shows a sectional view of the impeller 128 , 8th shows a sectional view of the wet-running pump 100 in the assembled state.

For operation of the wet-running pump 100 become the coils of the stator teeth 114 from the power electronics 120 controlled so that via the rotor, a torque on the impeller 128 acts. This then sucks the fluid 108 through the inlet nozzle 134 and the bearing, so that the fluid 108 through the wet runner pump 100 is conveyed through and this at the outlet 160 leaves.

LIST OF REFERENCE NUMBERS

100

Wet rotor

102

engine cover

104

front

106

opening

108

fluid

110

stator

112

Statorzahnaufnahme

114

stator tooth

116

containment shell

118

reception area

120

power electronics

122

permanent magnet

124

ring

126

The End

128

impeller

130

disc

132

recess

134

inlet port

136

circuit board

138

fastening area

140

hole

142

housing half

144

housing half

146

opening

148

fastening area

150

sheave

152

extension

153

screw

154

plain bearing element

156

bearing bush

158

screw

160

outlet

162

recess

164

end

166

edge

Claims (18)

Wet-runner pump with an axial flow motor, which has a stator ( 110 . 112 . 114 ), a containment shell ( 116 ) and a rotor ( 122 . 124 ), wherein the stator and the containment shell in a dry area and the rotor to an impeller ( 128 ) are arranged in a wet area, with an inlet line ( 134 . 156 ) for a fluid to be delivered by the impeller ( 108 ), and with a warehouse ( 154 . 156 ) for the impeller, wherein the bearing is disposed at one end of the inlet duct, and the bearing supports the impeller with an axial degree of freedom, wherein the inlet duct extends in the axial direction through the stator, the gap pot and the bearing, wherein the stator by a annular stator tooth receptacle ( 112 ) is formed, along whose circumference stator teeth ( 114 ), each of the stator teeth ( 114 ) a receiving area extending in the axial direction ( 118 ) for a coil. The wet-running pump according to claim 1, wherein the inlet line is formed at least by an inlet connection formed on the containment shell (US Pat. 134 ) and is formed by the bearing. A wet runner pump according to claim 2, wherein the containment shell is a disc ( 130 ), which projects into the air gap of the Axialflussmotors, and the containment shell is integrally formed, in particular as a molded part. Wet-running pump according to one of the preceding claims, wherein the stator is toroidal. A wet rotor motor according to one of the preceding claims, wherein the stator tooth receptacle is glued to the stator teeth. A wet rotor motor according to any one of the preceding claims, wherein the receiving area of each stator tooth is defined by an air gap side end ( 126 ) of the respective stator tooth is limited, wherein the air gap-side end of the stator tooth has an end face which is larger than the cross section of the receiving area. Wet-running pump according to one of the preceding claims, with power electronics 120 for controlling the stator, wherein the power electronics is arranged in the interior of the circumscribed between the stator and the containment shell space. A wet rotor motor according to any one of the preceding claims, wherein the containment shell is a disc ( 130 ) which projects into the air gap, wherein the disc has a central opening, on which an inlet port ( 134 ) is formed to the inlet of the fluid, wherein an end portion of the inlet nozzle receives the bearing. A wet rotor motor according to one of the preceding claims, wherein the bearing is a sliding bearing, which is designed for the radial mounting of the impeller and for one-sided axial bearing of the impeller as an abutment for the force exerted by the stator on the impeller magnetic attraction. A wet-running pump according to claim 8 or 9, wherein the bearing is arranged on the gap side by a bearing bush (10) arranged in the end region of the inlet nozzle ( 156 ) and impeller side by a sliding bearing element ( 154 ) is formed, which has a sliding surface ( 164 ), which engages in the bearing bush. A wet-running pump according to claim 10, wherein the sliding bearing element has a peripheral edge ( 166 ) which is arranged so that it on the bearing bush ( 156 ) forms a stop when a magnetic attraction force from the stator acts on the rotor in the axial direction. The wet-running pump of claim 10 or 11, wherein the sliding bearing member has one or more radially extending openings which are formed so that in operation, a portion of the fluid flow is passed between the sliding surface of the sliding bearing element and the sliding surface of the bearing bush. A wet-running pump according to any one of claims 8 to 12, wherein the disc has recesses ( 132 ) for receiving the air gap side end of the stator teeth. A wet rotor motor according to one of the preceding claims, wherein the sliding surface of the sliding bearing element and / or the sliding surface of the Bushing with a combination of Diamond-Like-Carbon (DLC) and silicon carbide (SiC) is coated. A wet rotor motor according to any one of the preceding claims, wherein the rotor includes samarium cobalt (SmCo). A wet-running pump according to one of the preceding claims, wherein the rotor is formed by a plurality of permanent magnets (12) arranged at the periphery of the impeller ( 122 ) or by a magnetic ring with multipolar magnetization is formed. A wet rotor motor as claimed in any one of the preceding claims, wherein a seal is formed by the bearing. Wet-rotor motor according to one of the preceding claims, wherein the permanent magnets ( 122 ) are shorter in the radial direction than the ends ( 126 ) of the stator teeth ( 114 ).

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