Cable bushing

Abstract

The invention relates to a pump assembly having a pump (1) driven by a wet rotor motor (2), the wet rotor motor (2) being surrounded by a motor housing (3) and having a stator winding (24). The motor housing (3) comprises a bushing assembly (4) for powering a stator winding (24) of the wet rotor motor (2). The bushing assembly (4) has an opening (6) on a portion (5) of the motor housing (3), into which opening a line bushing (7) is arranged in a fastened manner by means of a retaining element (8). The line bushings (7) each have an electrical conductor (9) and an insulating body (10). The electrical conductor (9) and the stator winding (24) have a connection (15), the connection (15) being designed as a crimp connection.

Description

(19) State Intellectual Property Office (12) Invention Patent Application (10) Application Publication Number (43) Application Publication Date (21) Application Number 202480028528.1 (22) Application Date 2024.04.25 (30) Priority Data 102023111033.0 2023.04.28 DE (85) PCT International Application Entering National Phase Date 2025.10.27 (86) PCT International Application Application Data PCT / EP2024 / 061429 2024.04.25 (87) PCT International Application Publication Data WO2024 / 223756 DE 2024.10.31 (71) Applicant KSB GmbH Address Frankenthal, Germany (72) Inventor P. Hauk R. Meyer S. Altmann (74) Patent Agency China Patent Agency (Hong Kong) Limited 72001 Patent Agents: Wei Chengyang, Sun Yier (51) Int.Cl. H02K 5 / 132 (2006.01) H02K 7 / 14 (2006.01) H02K 5 / 22 (2006.01) F04D 13 / 06 (2006.01) (54) Invention Title: Wiring Bushing (57) Abstract: This invention relates to a pump unit having a pump (1) driven by a wet rotor motor (2), wherein the wet rotor motor (2) is surrounded by a motor housing (3) and has stator windings (24). The motor housing (3) includes a bushing assembly (4) for supplying power to the stator windings (24) of the wet rotor motor (2). The bushing assembly (4) has an opening (6) at a portion (5) of the motor housing (3), into which wiring bushings (7) are respectively fastened by means of retaining elements (8). The bushing (7) has a conductor (9) and an insulator (10). The conductor (9) and the stator winding (24) have a connection (15), wherein the connection (15) is constructed as a crimp connection.Claims 1 page, Description 6 pages, Drawings 5 ​​pages, CN 121039934 A 2025.11.28 CN 1 21 03 99 34 A 1. A pump unit having a pump (1) driven by a wet rotor motor (2), - wherein the wet rotor motor (2) is surrounded by a motor housing (3) and has stator windings (24), - wherein the motor housing (3) includes a bushing assembly (4) for supplying power to the stator windings (24) of the wet rotor motor (2), and the bushing assembly (4) has an opening (6) at a portion (5) of the motor housing (3), into which wiring bushings (7) are respectively fastened by means of retaining elements (8), - wherein each wiring bushing (7) has a conductor (9) and an insulator (10), 1. The pump unit according to claim 1, wherein the conductor (9) and the stator winding (24) have a connecting portion (15), wherein the connecting portion (15) is configured as a press-fit connection. 2. The pump unit according to claim 1, wherein the conductor (9) has a protrusion configured as a hollow cylinder (47). 3. The pump unit according to claim 1 or 2, wherein the stator winding (24) has at least one wire end (18) introduced into the hollow cylinder (47). 4. The pump unit according to claim 2 or 3, wherein the hollow cylinder (47) and the wire end (18) have a force-fit connecting portion (15). 5. The pump unit according to any one of claims 1 to 4, wherein the connecting portion (15) at least partially comprises at least four, preferably at least six, outer surfaces, wherein two outer surfaces are respectively arranged opposite to each other. 6. The pump unit according to any one of claims 1 to 5, wherein the insulator (10) has at least a partially conical surface that interacts with the conductor (9). 7. The pump unit according to any one of claims 1 to 6, characterized in that the conductor (9) has at least a partially conical surface. 8. The pump unit according to any one of claims 1 to 7, characterized in that the conductor (9) comprises a rod-shaped portion (11) and a portion in the form of a double cone (12). 9. The pump unit according to any one of claims 1 to 8, characterized in that the insulator (10) is configured to shrink-fit onto the conductor (9). 10. The pump unit according to any one of claims 1 to 9, characterized in that the insulator (10) is constructed of high-performance plastic. 11. The pump unit according to any one of claims 1 to 10, characterized in that the insulator (10) has a metallized portion. 12. The pump unit according to any one of claims 1 to 11, characterized in that the bushing (7) has a field control element (45).13. A method for manufacturing a pump unit having a pump (1) driven by a wet rotor motor (2), wherein a bushing assembly (4) for supplying power to the wet rotor motor (2) comprises a line bushing (7) having a conductor (9) and an insulator (10), characterized in that, for each line bushing (7), the wire end (18) of the stator winding (24) is introduced into a hollow cylinder (47) of the conductor (9), and a form-fitting connection (15) is formed by means of a pressing tool. 14. Use of a pump unit having a pump (1) in a power plant circuit with high system pressure, for sealing the power supply of the wet rotor motor (2) against high system pressure by means of a line bushing (7). Claims 1 / 1 Page 2 CN 121039934 A Bushing Technical Field

[0001] The present invention relates to a pump unit having a pump driven by a wet rotor motor, wherein the wet rotor motor is surrounded by a motor housing and has stator windings, wherein the motor housing includes a bushing assembly for supplying power to the stator windings of the wet rotor motor, and the bushing assembly has an opening at a portion of the motor housing, wherein bushings are respectively arranged therein in a fastening manner by means of retaining elements, wherein each bushing has a conductor and an insulator. Background Art

[0002] Such pump units can be used, for example, in the construction of power plants. The housing components constitute a pressure sleeve, which limits the internal space relative to the surrounding atmosphere. Pressure sleeves are mostly designed for very high system pressures.

[0003] An exemplary device is described in EP 1 910 685 B1. The device includes a pump driven by a liquid-filled motor. The motor has a housing that is part of the pressure sleeve.

[0004] Sealless circulating pumps are also called sealless circulating pumps and are typically vertical pumps driven by a wet rotor motor with or without an isolation tube.

[0005] Wet rotor motors are mostly asynchronous squirrel-cage motors, with their rotors and bearings operating in the conveyed medium. Special care is required in the design, assembly, and commissioning of wet rotor motors to ensure reliable filling and venting of the internal space of the motor and to keep solids in the conveyed medium away from the liquid-lubricated sliding bearings.

[0006] Here, the pump and motor are housed in a common, pressure-resistant housing with thermal insulation between the pump and motor sections. The thermal insulation can be implemented as an active or passive structural element and allows for temperatures of the conveyed medium up to 420°C. The bearings are lubricated by the conveyed medium and require no dynamic seals.

[0007] The wet rotor motor is completely filled with liquid. The stator and windings (including supply line connections) are also submerged in liquid, utilizing the rotor and its bearings. This is contingent upon waterproof and pressure-resistant insulation of all live parts.In conventional power plants, wet rotor motors are used as drive motors for sleeveless circulating pumps.

[0008] In conventional bushing assemblies for powering wet rotor motors, the insulation can be constructed in two pieces. It consists of an inner insulator and an outer insulator.

[0009] A bushing assembly with a single insulator surrounding a current conductor is known from US 3,043,903A.

[0010] JP S55 15968 U describes an insulating element installed at a cable, which guides the cable through a bushing opening in the body of an electrical device. A flange-like protrusion is constructed in a section of the insulating element that abuts against a shoulder in the body of the device and is secured by a retaining sleeve.

[0011] In known bushing assemblies, the inner insulator forms the pressure-bearing portion. The outer insulator is arranged above the inner insulator. Under combined action, the two insulators require a long overlap to achieve the necessary creepage distance. This increases structural space. In high-load situations, metal rings are used for protection. These metal rings require additional sealing points and may generate heat due to eddy currents.

[0012] DE 10 2014 209 517 A1 discloses an apparatus with a pump driven by a wet rotor motor. The apparatus has a housing that includes a bushing assembly for supplying power to the wet rotor motor. The bushing assembly has wiring elements and an insulator. The bushing assembly includes a force transmission element. Specification 1 / 6 pages 3 CN 121039934 A

[0013] For wet rotor motors, especially under high fluid pressure, the weakness of the wiring bushing lies in its sealing relative to ambient pressure and its protection against breakage in accidental situations. Summary of the Invention

[0014] The object of the present invention is to provide a pump unit with a pump and a wiring bushing that is constructed very compactly. Furthermore, the wiring bushing should ensure a high degree of safety and occupy as little structural space as possible. Here, as few sealing points as possible are required.

[0015] According to the invention, this object is achieved by a pump unit with a pump according to the features of claim 1. Preferred variations can be seen from the parallel main claims, dependent claims, description, and drawings.

[0016] According to the invention, the conductor and the stator winding have a connection portion, wherein the connection portion is constructed as a crimp connection portion.

[0017] A crimp connection portion is a connection between two components made by friction between the two components. A crimp connection portion belongs to the force-fit connection portion of the joining technology and is standardized by DIN 8593.

[0018] Preferably, each conductor has a connection portion with a plastic-insulated wire of the stator winding of a wet rotor motor. In a suitable variation of the invention, the connection portion is constructed as a crimp connection portion.

[0019] In an advantageous variation of the invention, the conductor has a protrusion constructed as a hollow cylinder.

[0020] Ideally, the stator winding conductor has at least one end that is introduced into the hollow cylinder. Here, the end of the plastic-insulated conductor up to the section introduced into the hollow cylinder is insulated with PE insulation.

[0021] Advantageously, the hollow cylinder of the conductor and the end of the stator winding conductor have a force-fit connection.

[0022] In a particularly suitable variation, the connection (especially a crimped connection) is implemented as a spliced ​​connection.

[0023] Splicing is understood as a joining method in which two components are connected to each other by plastic deformation, for example by flanging, pressing, crimping, or folding. The spliced ​​connection can only be conditionally loosened and can only be replaced during maintenance using suitable tools.

[0024] When spliced, an airtight connection is formed when implemented correctly. By deforming the spliced ​​sleeve in the form of a hollow cylinder protruding from the conductor and wire, a structure that is as oxygen-isolated as possible and therefore as internally protected against corrosion as possible is formed.

[0025] Ideally, the protrusions of the wire and the conductor are constructed of the same material (preferably copper). Copper is an almost ideal conductor, especially for applications in wet rotor motors. Copper-based splicing achieves excellent and virtually lossless conductivity.

[0026] Advantageously, the hollow cylindrical protrusion of the conductor is an ideally integrated connecting bolt with the conductor in a one-piece implementation. Therefore, no additional components are required, thereby saving further assembly costs and avoiding line losses due to the use of additional components. The splicing connection between the wire and the conductor is advantageously achieved directly.

[0027] Preferably, the cylindrical connecting wire or winding wire in the form of a wire is directly introduced into the cylindrical cavity of the protrusion below the double cone of the conductor and ideally conductively connected with a force fit.

[0028] Compared with known wiring sleeves for wet rotor motors, no hard soldering is required. Therefore, excessive heat input to the connection is avoided, thereby preventing load on the conductive connection and insulation aging. Furthermore, the use of solder, which is not always ideally conductive, can be eliminated.

[0029] In an advantageous variation of the invention, the connecting portion at least partially comprises at least four, preferably at least six, outer surfaces, wherein two outer surfaces are arranged opposite to each other. The splicing connection preferably deforms the cylindrical protrusion of the conductor into a hexagonal shape, thereby forcefully securing the introduced cylindrical wire in the protrusion of the conductor. Specification 2 / 6 pages 4 CN 121039934 A

[0030] The connecting portion and the conductor are preferably covered by a shrink tube up to at least the insulator.

[0031] In an advantageous variation of the invention, the insulator has at least a partially conical surface that interacts with the conductor.

[0032] A cone is a geometry formed when all points of a confined and continuous planar segment in a plane are linearly connected to points outside the plane.In the special case of a circular surface segment, the body is also called a cone. If the axis is perpendicular to the bottom surface, a straight cone exists.

[0033] Ideally, the conical surface of the insulator is constructed as a partial surface of a straight cone.

[0034] Preferably, the conductor has at least a partially conical surface. In a particularly advantageous variant of the invention, the conical surface of the conductor is constructed as a partial surface of a straight cone.

[0035] The conical surface of the conductor and the conical surface of the insulator advantageously work together. In a particularly advantageous variant of the invention, the conical surface of the conductor and the conical surface of the insulator are constructed as corresponding acting surfaces.

[0036] The conductor preferably includes a rod-shaped portion and a portion in the form of a double cone. The conductor is preferably constructed as an elongated, preferably cylindrical rod, with a connection portion for the conductor of the stator winding arranged at its end. Advantageously, a thickened portion in the form of a double cone is constructed at the end of the conductor and in front of the connection portion with the conductor, which forms the conical surface of the conductor.

[0037] Ideally, the insulator is configured to shrink-fit onto the conductor. Here, the shrink-fit compound extends to the maximum length of the rod-shaped portion of the conductor and connects to the bicone at the transition. Here, the conical surfaces of the insulator and the conductor form a particularly stable end section of the shrink-fit compound. Ideally, the insulator is subjected to significantly less mechanical load at the bicone by shrink-fitting, and thus also achieves a long service life during operation.

[0038] Furthermore, shrink-fitting the insulator onto the conductor provides advantageous torsional protection, especially compared to adhesive bonding to date.

[0039] Ideally, the conical surfaces of the insulator and the conductor work together. This working together begins by shrink-fitting the insulator onto the conductor. Additionally, an O-ring that acts as a seal is embedded in the conductor at the transition of the conical surface, so that if the conical surface of the insulator suffers damage to the connection on the conical surface of the conductor, there is redundant protection against fluid leakage.

[0040] Advantageously, a thickened portion in the form of a bicone is constructed at the end of the conductor and in front of the connection with the wire, forming a conical surface of the conductor. This bicone provides advantageous protection against breakage or breakdown of the bushing.

[0041] In a particularly advantageous variant of the invention, the insulator is constructed of a high-performance plastic. High-performance plastics are a subclass of thermoplastics, which are advantageously distinguished from engineering plastics and standard plastics, particularly by their high-temperature resistance, but also by their chemical resistance and mechanical properties.

[0042] In a particularly advantageous variant of the invention, the insulator is constructed of polyetheretherketone (PEEK).

[0043] PEEK is a high-temperature resistant thermoplastic and belongs to the polyaryletherketone material category. Its melting point is 335 °C.PEEK is resistant to almost all organic and inorganic chemicals, high-energy electromagnetic waves (e.g., gamma rays and X-rays), and also resistant to hydrolysis up to about 280°C. PEEK is preferably used as an insulating material in high-voltage technology due to its excellent electrical insulation properties and low dielectric loss factor.

[0044] The insulator preferably has an elongated shape with an internal cylindrical cavity. A conductor is introduced into the cavity, and the insulator contracts to fit onto the conductor. A thickened portion is preferably arranged in the central portion of the insulator, configured as a base for a bushing with an opening in the housing. For this purpose, the thickened portion has a first notch along the direction of the housing opening for realizing an O-ring, which performs the task of sealing the bushing in the housing opening.

[0045] Additionally, the thickened portion of the insulator has another notch at the center of the thickened portion, into which another O-ring can be realized for sealing. The second O-ring is advantageously configured as a redundant seal for the bushing in the opening of the housing. In unfavorable accident conditions (where high pressure and elevated temperature occur), the other O-ring can maintain the seal after the first O-ring loses its sealing function. For this purpose, the second O-ring is positioned such that there is no direct contact, and in the event of damage to the first O-ring, there is no large-area contact with hot liquid.

[0046] Furthermore, the thickened portion on the side opposite to the O-ring has a base for the ring configured as a fracture protection device. Ideally, the ring can be implemented as a metal ring, wherein the metal material (e.g., brass or iron) is non-magnetic. In addition, high-temperature resistant plastics are also suitable. In the case of so-called fracture, i.e., the insulator breaks and the conductor is pressed out of the bushing, the ring, in combination with the biconical portion of the conductor, prevents actual fracture or breakdown for fracture protection and advantageously seals against fluid pressures occurring in a wet rotor motor.

[0047] In a suitable variant of the invention, the insulator has a metallized portion.

[0048] For this purpose, the metallization is preferably implemented as an alternative to the nickel layer, which achieves repeatable conductivity through a defined layer thickness. The nickel layer is preferably coated in the inner hollow cylinder of the insulator. This is a significant improvement in repeatable conductivity, especially compared to conventionally known manually applied conductive paint.

[0049] The combination of the shrinkage fit of the insulator and the metallization on the inner side of the insulator achieves gapless and airless contact between the conductor and the insulator. Therefore, partial discharge caused by the implementation of the bushing is particularly effectively avoided or significantly reduced.

[0050] Compared to known bushings, the bushing according to the invention requires neither sealing tape nor conductive paint nor adhesive, thereby achieving an extremely strong connection between the conductor and the insulator, which also has improved field control characteristics.

[0051] Ideally, the bushing has a field control varnish. In a suitable variation of the invention, the bushing has a field control element, thereby significantly reducing the maximum field strength and simultaneously increasing the partial discharge initiation voltage.

[0052] So-called field control includes all measures for reducing the local electric field strength to such an extent that it does not exceed the electrical strength of the insulating material and interface at any point.

[0053] For example, the field control varnish or field control element has a dielectric constant that is significantly increased relative to the insulator, thereby enabling a targeted reduction of the original field strength.

[0054] In a suitable variation of the invention, the bushing has another outer insulator. Preferably, this other outer insulator is positioned above the contraction-fit insulator and within a non-magnetic threaded bushing that secures the bushing in the opening of the housing. Additionally, the outer insulator can be adjusted at its upper end using a fastening element. Preferably, the threaded bushing is implemented with an M64 external thread.

[0055] In a suitable variation of the invention, the bushing assembly includes three bushings. In an alternative variation, six line bushings can also be implemented in the bushing assembly.

[0056] According to the invention, a pump unit with a pump driven by a wet rotor motor, wherein the bushing assembly for supplying power to the wet rotor motor comprises at least one line bushing having a conductor and an insulator, manufactured in such a way that the insulator is contractively fitted onto the conductor, and for each line bushing, the stator winding ends are introduced into the hollow cylinder of the conductor, and a form-fitting connection is created by means of a pressing tool.

[0057] According to the invention, a pump unit with a pump is used in a power plant circuit with high system pressure for sealing the power supply of the wet rotor motor with line bushings to prevent high system pressure.

[0058] Further features and advantages of the invention will become apparent from the description of the embodiments with reference to the accompanying drawings and from the drawings themselves. Specification 4 / 6 pages 6 CN 121039934 A Description of Drawings

[0059] Herein: FIG1 shows a cross-sectional view of the motor pump unit; FIG2 shows a perspective view of the bushing assembly; FIG3 shows a cross-sectional view of the bushing assembly; FIG4 shows a cross-sectional view of the line bushing; FIG5 shows a detailed view of the line bushing. Detailed Description

[0060] FIG1 shows a motor pump unit with a wet rotor motor 2. The motor housing 3 forms part of the pressure sleeve. The interior of the wet rotor motor 2 is filled with liquid and has a heat insulation section 25. A cooling system 17 is provided to dissipate electrical loss power. The wet rotor motor 2 includes two radial bearings 13, 14 and one axial bearing 40.

[0061] The driving force of the wet rotor motor 2 acts on the shaft system 18 and thus transmits torque to the pump 1. The pump 1 includes a pump housing 19 in which an impeller 20 and a guide device 21 are arranged.The pump housing 19 is connected to the motor housing 3 via at least four tie rods 22.

[0062] The motor housing 3 and the pump housing 19 together form a pressure sleeve. This pressure sleeve is designed for high system pressure.

[0063] The wet rotor motor 2 shown in this embodiment is completely filled with liquid. The stator winding 24 and the stator winding head 16 (including the supply line connection part) are also in the liquid using the rotor 23 and its bearings. In order to supply power to the wet rotor motor 2, a bushing assembly 4 is provided in the motor housing 3. For this purpose, plastic-insulated copper wire 27 (which has PE insulation in this embodiment) is connected from the multilayer coil of the stator winding 24 to the line bushing 7 by means of a connection part 15.

[0064] The bushing assembly 4 includes a portion 5 formed by a collar-shaped protrusion. The portion 5 is constructed as a single piece with the motor housing 3, thereby also being able to withstand high fluid pressure. The portion 5 of the motor housing 3 has an opening 6 into which the line bushing 7 is respectively arranged. The number of openings 6 corresponds to the number of wiring sleeves 7 required for operating the wet rotor motor 2. As can be seen from Figure 4, each of the openings 6 has a section 43 with a reduced inner diameter and a section 42 with an increased inner diameter.

[0065] A junction box 28 is arranged at the sleeve assembly 4, into which the wiring sleeves 7 pass. A connector 29 is positioned in the junction box 28 for mechanical decoupling of the so-called conductive expansion band 30. In this embodiment, the connector 29 is implemented as an epoxy resin insulator.

[0066] Figure 2 shows a perspective view of the sleeve assembly 4 with three wiring sleeves 7. As can be seen in conjunction with Figure 3, the wiring sleeves are fastened in the openings 6 of the portion 5 of the motor housing 3 by means of a retaining element 8. An outer insulator 26 covers the retaining element 8. For this purpose, the outer insulator 26 is inserted into the inner insulator 10 and fastened at the top with a washer 32 and a nut 31.

[0067] The retaining element 8 is implemented as a non-magnetic threaded bushing, for example, with an M64 external thread. In the illustrated embodiment, the junction box 28 is located directly on the collar-shaped protrusion of portion 5 of the motor housing 3. Three wiring sleeves 7 pass into the junction box 28 and have a connection to each of the conductive expansion bands 30, which in turn are connected to each of the connecting pipes 29 for mechanical decoupling.

[0068] FIG4 shows a detailed cross-sectional view of the wiring sleeve 7. The wiring sleeve 7 includes a conductor 9 having a rod-shaped portion 11 and a double cone 12. The double cone 12 realizes the tapered surface of the conductor 9, which is constructed as a partial surface of a straight circular cone. The conductor 9 is largely constructed as an elongated, cylindrical rod with an unshown connection at its end (under reference numeral 44) to a copper wire 27 that is plastic-insulated from the stator winding 24. The conical surface of the conductor 9 and the conical surface of the insulator 10 interact with each other and form corresponding interaction surfaces 41.

[0069] The insulator 10 is made of polyetheretherketone (PEEK) and is configured to shrink fit onto the conductor 9. Here, the shrink-fit composite extends at least half the length of the rod-shaped portion 11 of the conductor 9 and extends to the bicone 12 at the transition. By shrink fitting at the bicone 12, the composite consisting of the insulator 10 and the conductor 9 is significantly less subjected to mechanical loads, and thus also provides a long service life during operation.

[0070] The insulator 10 has a metallization in the form of an alternative nickel layer applied in the hollow cylinder inside the insulator 10. This achieves repeatable conductivity with a defined layer thickness.

[0071] The line sleeve 7 has another outer insulator 26 and is positioned above the shrink-fit insulator 10 and inside a non-magnetic threaded bushing 8, which secures the line sleeve 7 in the opening 6 of the housing 3. The outer insulator 26 is adjusted at its upper end using a washer 32 and a nut 31. The threaded bushing 8 is implemented with external threads. The distance sleeve 46 is constructed of PEEK and has a positioning field control element 45.

[0072] A thickened portion 33 is arranged in the central portion of the insulator 10, which is configured as the base of the bushing 7 within the opening 6 of the housing 3. For this purpose, the thickened portion 33 has a first notch or chamfer 34 in the region of the section 42 of the opening 6 of the housing 3 to realize a first O-ring 35, which undertakes the task of sealing the bushing 7 in the opening 6 of the housing 3.

[0073] Additionally, the thickened portion 33 of the insulator 10 has a second notch 36 in the form of a radially circumferential groove at the center of the thickened portion 33, into which a second O-ring 37 can be realized for sealing. The second O-ring 37 advantageously provides redundant sealing for the bushing 7 in the opening 6 of the housing 3. In unsuitable accident conditions (where high pressure and elevated temperature occur), the second O-ring 37 can maintain the sealing effect after the sealing effect of the first O-ring 35 is lost.

[0074] The thickened portion 33 has a base for a ring 38 on the side opposite to the first O-ring 35, which is configured as a breakage protection device. The ring 38 is implemented as a metal ring. The metal ring is preferably constructed as a brass ring or a ring made of non-magnetic iron. In the case of so-called breakage, i.e., the insulator 10 breaks and the conductor 9 is pressed out of the bushing 7, the ring 38, in combination with the double cone 12 of the conductor 9, prevents leakage from the insulator 10 for breakage protection.

[0075] Additionally, a third O-ring 39, which plays a sealing role, is embedded in the conductor 9 at the transition between the conical surfaces of the insulator 10 and the conductor 9, so that if the conical surface of the insulator 10 is partially damaged at the conical surface of the conductor 9, there is redundant protection against fluid leakage.

[0076] FIG5 shows a detailed view of the line bushing 7 (especially the connection portion 15 implemented as a crimped connection or spliced ​​connection).The conductor 9 has a protrusion constructed as a hollow cylinder 47. The cylindrical wire end 18 of the conductor 27 is introduced into the hollow cylinder 47 and joined together by a pressing tool to form a force-fit connection 15.

[0077] The conductor 27 (including the cylindrical wire end 18 and the protrusion of the conductor 9) is constructed of copper. The copper-based crimped connection achieves excellent and almost lossless conductivity. Specification 6 / 6 page 8 CN 121039934 A Figure 1 Specification Figure 1 / 5 page 9 CN 121039934 A Figure 2 Specification Figure 2 / 5 page 10 CN 121039934 A Figure 3 Specification Figure 3 / 5 page 11 CN 121039934 A Figure 4 Specification Figure 4 / 5 page 12 CN 121039934 A Figure 5 Specification Figure 5 / 5 page 13 CN 121039934 A.

Claims

1. A pump unit comprising a pump (1) driven by a wet rotor motor (2), - in, The wet rotor motor (2) is surrounded by a motor housing (3) and has stator windings (24). - The motor housing (3) includes a bushing assembly (4) for supplying power to the stator windings (24) of the wet rotor motor (2), and the bushing assembly (4) has an opening (6) at a portion (5) of the motor housing (3), into which line bushings (7) are respectively fastened by means of retaining elements (8). - The line bushing (7) has a conductor (9) and an insulator (10). The feature is that the conductor (9) and the stator winding (24) have a connecting portion (15), wherein the connecting portion (15) is configured as a press-fit connection portion.

2. The pump unit according to claim 1, characterized in that, The conductor (9) has a protrusion constructed as a hollow cylinder (47).

3. The pump unit according to claim 1 or 2, characterized in that, The stator winding (24) has at least one wire end (18) introduced into the hollow cylinder (47).

4. The pump unit according to claim 2 or 3, characterized in that, The hollow column (47) and the wire end (18) have a force-fitting connecting part (15).

5. The pump unit according to any one of claims 1 to 4, characterized in that, The connecting portion (15) includes at least four, preferably at least six, outer surfaces, wherein two outer surfaces are arranged opposite to each other.

6. The pump unit according to any one of claims 1 to 5, characterized in that, The insulator (10) has at least a partially tapered surface that interacts with the conductor (9).

7. The pump unit according to any one of claims 1 to 6, characterized in that, The conductor (9) has at least a partially conical surface.

8. The pump unit according to any one of claims 1 to 7, characterized in that, The conductor (9) includes a rod-shaped portion (11) and a portion in the form of a double cone (12).

9. The pump unit according to any one of claims 1 to 8, characterized in that, The insulator (10) is configured to shrink and fit onto the conductor (9).

10. The pump unit according to any one of claims 1 to 9, characterized in that, The insulator (10) is constructed of high-performance plastic.

11. The pump unit according to any one of claims 1 to 10, characterized in that, The insulator (10) has a metallized portion.

12. The pump unit according to any one of claims 1 to 11, characterized in that, The line bushing (7) has a field control element (45).

13. A method for manufacturing a pump unit, the pump unit having a pump (1) driven by a wet rotor motor (2), wherein, The bushing assembly (4) for supplying power to the wet rotor motor (2) includes a line bushing (7) having a conductor (9) and an insulator (10), characterized in that, for each line bushing (7), the wire end (18) of the stator winding (24) is introduced into the hollow column (47) of the conductor (9), and a form-fitting connection (15) is generated by means of a pressing tool.

14. Use of a pump unit with a pump (1) in a power plant circuit with high system pressure, for sealing the power supply of the wet rotor motor (2) with a bushing (7) to prevent high system pressure.

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