METHOD FOR MANUFACTURING A SUBMERSIBLE MOTOR PUMP

Description

Technical area

[0001] The invention relates to a method for producing a submersible motor pump, in particular for conveying dirty water and / or waste water, and comprising a cylindrical pot housing forming an interior space between an open base surface and a cover surface axially opposite the base surface, with a plug connector opening provided in the pot housing and a motor provided in the interior space with a cylindrical stator having a plurality of windings and a first plug connector connected to ends of the windings.The invention further relates to a submersible motor pump for conveying dirty water and / or waste water, comprising a cylindrical pot housing forming an interior space between an open base surface and a cover surface axially opposite the base surface, with a plug connector opening provided in the pot housing and a motor provided in the interior space with a cylindrical stator having a plurality of windings and a first plug connector connected to ends of the windings. Background of the invention

[0002] Submersible pumps are known from the prior art and are used to pump a fluid using the rotating motion of an impeller. The fluid to be pumped enters a pump chamber of the submersible pump through a suction port, is captured by the rotating impeller, and is then often transported into a section of pipe, also known as a discharge pipe.

[0003] Such submersible motor pumps, as disclosed, for example, in US5567170A, often have a housing in the form of a cylindrical pot housing with a motor provided in an interior space for driving the impeller located beneath the pot housing. Such a motor has a cylindrical stator having a plurality of windings, the ends of which are provided with a first connector. Typically, an opening is provided in a top surface of the pot housing, through which a cable having a second connector is passed. The second connector is electrically connected to the first connector within the pot housing.

[0004] Even if such a design ensures reliable operation of the submersible pump, installing the plug-in connector is complex. To connect, the first connector must be routed out of the opening, connected to the second connector outside the housing, and finally, the connected first and second connectors must be inserted through the opening back into the housing. Finally, the cable must be sealed at the opening to the housing. Description of the invention

[0005] Based on this situation, it is an object of the present invention to provide a method for producing a submersible motor pump and a corresponding submersible motor pump which is significantly easier to produce than the previously described submersible motor pump.

[0006] The object of the invention is achieved by the features of the independent claims. Advantageous embodiments are specified in the subclaims.

[0007] Accordingly, the object is achieved by a method for producing a submersible motor pump, in particular for conveying dirty water and / or waste water and comprising a cylindrical pot housing forming an interior space between an open base surface and a cover surface axially opposite the base surface, with a plug connector opening provided in the pot housing, a motor provided in the interior space with a cylindrical stator having a plurality of windings and a first plug connector connected to ends of the windings, in particular oriented towards the cover surface and provided with at least one radially resilient latching tab, and with the steps of: gripping the first plug connector from outside the pot housing through the plug connector opening, inserting the first plug connector from the interior space into the plug connector opening, and latching the at least one latching tab to the pot housing.

[0008] The object is further achieved by a submersible motor pump, in particular for conveying dirty water and / or waste water and comprising a cylindrical pot housing forming an interior space between an open base surface and a cover surface axially opposite the base surface, said pot housing having a plug connector opening provided in the pot housing, and a motor provided in the interior space with a cylindrical stator having a plurality of windings and a first plug connector connected to ends of the windings, in particular oriented towards the cover surface and provided with at least one latching tab, wherein the first plug connector can be inserted from outside the pot housing through the plug connector opening from the interior space into the plug connector opening for latching the at least one latching tab to the pot housing.

[0009] A key feature of the proposed method and the proposed submersible motor pump, hereinafter referred to collectively as the submersible motor pump, is that, unlike prior art designs, the first connector does not need to be led out of the pot housing to connect to a second connector, nor does it need to be reinserted into the pot housing after the two connectors have been connected, nor does it need to be sealed off from the pot housing by a cable connected to the second connector. Because the first connector can be latched onto the pot housing, the second connector can be easily plugged onto the latched first connector for a moisture-tight connection, which significantly simplifies the assembly of the submersible motor pump.In addition, the proposed submersible pump can enable a type of sealless sealing system by locking the first connector to the top housing.

[0010] Submersible pumps are generally suitable for pumping any type of fluid. Due to their robustness against solids and chemicals, submersible pumps are particularly suitable for use as submersible pumps for dirty water and / or wastewater. Submersible pumps for dirty water and / or wastewater are used primarily for pumping contaminated water, for example, from floods, flooded excavations, laundry rooms, muddy pits, biotopes and / or garden ponds, leaching shafts, and basements. They are especially suitable for pumping water with varying degrees of contamination, such as stones, mud, debris, or feces.In addition, the submersible motor pump can also be used for heating with radiators, radiator heating, underfloor heating, ceiling cooling, water circulation in a drinking water system, or a drinking water system with a storage charging system. The above list is not exhaustive, but may include other types of systems not mentioned here. The motor is located within the pot housing, which is preferably designed to be moisture-tight. The motor typically drives an impeller connected to the motor via a motor shaft to pump the fluid. The submersible motor pump can be designed as a centrifugal pump.

[0011] The pot housing is preferably designed to be closed except for the connector opening and the open base surface, in particular designed to be moisture-tight. The connector opening is preferably provided in the cover surface axially opposite the base surface, but can alternatively also be provided in the outer surface of the pot housing. The connector opening is preferably circular. In addition to the stator, the motor preferably has a rotor, which can be designed integrally with the motor shaft. The stator can be made of sheet steel and serves, in a known manner, as a common core for the windings, which are also called induction coils.

[0012] The ends of the windings are preferably led out of the cylindrical stator as stranded wires in the axial direction and are electrically connected to the first connector. The windings are preferably designed as stranded wires. The radially resilient locking tab is preferably designed so that the spring force acts radially outward. This means that the locking tab can be compressed inward toward a longitudinal axis of the connector against the spring force for inserting the first connector into the connector opening or, due to the spring force, tends away from the longitudinal axis. The locking tab preferably extends in the axial direction, in particular parallel to plug contacts of the first connector.

[0013] In the proposed submersible motor pump, it is particularly assumed that the stator is arranged in the pot housing such that the ends of the windings, and thus the first connector, are oriented toward the cover surface. After the at least one locking tab has been engaged with the pot housing, in particular at the connector opening, the first connector is connected to the pot housing in a form-fitting, force-fitting, and / or moisture-tight manner. However, the ends of the windings, and thus the first connector, can also be oriented toward the base surface.

[0014] According to a preferred development of the method or of the submersible motor pump, the first connector has one, in particular two, three or more, radially fixed gripping tabs, so that by gripping the gripping tab and the locking tab, in particular by means of a tool, the at least one locking tab can be radially compressed to insert the first connector into the connector opening. The gripping and / or insertion of the tool preferably takes place in the axial direction relative to the first connector. The radially fixed gripping tab preferably extends in the axial direction and / or is arranged radially adjacent to the locking tab. The locking tab can have a radially extending locking tab opening and / or the gripping tab can have a radially extending gripping tab opening into which the tool can be inserted axially to compress the locking tab.Such a gripping tab makes it particularly easy to grip the first connector and to insert it into the connector opening without damaging the first connector.

[0015] According to a further preferred development of the method or of the submersible motor pump, a holding device for the first connector is provided in the interior and associated with the connector opening, wherein the first connector is arranged in the holding device for gripping the first connector. The holding device is preferably designed as a type of shelf or holder into which the first connector is inserted when the stator is inserted into the pot housing or when the stator is placed on the pot housing. The stator can be gripped from this holding device in a simple and defined manner in order to be inserted into the connector opening. The holding device is preferably arranged axially below the connector opening, as viewed from the outside through the connector opening.

[0016] According to another preferred development of the method or the submersible motor pump, the first connector has a non-rotationally symmetrical cross-section, and the connector opening has a cross-section that corresponds or does not correspond to the first connector, so that the first connector is secured or not secured against rotation in the connector opening. Furthermore, such a non-rotationally symmetrical cross-section allows a defined plug-in position to be formed, into which the second connector can be inserted for connection to the first connector.

[0017] According to a further preferred development of the method or the submersible motor pump, the connector opening is provided in the cover surface or in a lateral surface of the pot housing. Particularly preferably, the holding device is provided directly below the connector opening. The connector opening preferably corresponds in its inner diameter to an outer diameter of the first connector, so that the latter can be fixed in place in the connector opening.

[0018] According to another preferred development of the method or the submersible motor pump, a second plug connector which can be connected to the first plug connector and has a metal sleeve and a second plug contact body made of plastic which holds a plurality of second plug contacts is provided, wherein the second plug contact body has a radially outwardly extending locking lug made of plastic and the metal sleeve has a corresponding radially outwardly extending locking recess and a radially inwardly extending locking lug made of metal such that when the second plug contact body is inserted into the metal sleeve, the locking lug made of metal first presses the locking lug made of plastic radially inwards and, after locking the locking lug made of plastic with the locking recess, locks into the second plug contact body in a sealing manner, in particular without a seal.

[0019] According to a further preferred development of the method or the submersible motor pump, a second plug connector which can be connected to the first plug connector and has a second plug contact body which holds a plurality of second plug contacts and forms a second plug face, wherein the second plug connector has a filling opening on the plug face side for potting the plurality of second plug contacts in the second plug contact body with potting material and an overflow volume which is offset axially opposite the filling opening for collecting excess potting material emerging from the filling opening.

[0020] The second plug contact body, like a first plug contact body of the first connector, is preferably made of plastic. The filler opening and / or the overflow volume preferably extends axially into the second plug contact body. Offset means, in particular, that the overflow volume is arranged axially away from the plug face relative to the filler opening, in particular in the direction of a cable connected to the second connector, so that excess potting material can "overflow" from the filler opening into the overflow volume. The potting of the second plug contact body preferably takes place after the second plug contacts have been connected to strands of a cable and when the second plug contact body connected in this way is inserted into a second plug contact housing described below.

[0021] According to another preferred development of the method or the submersible motor pump, a second plug connector connectable to the first plug connector is provided, comprising a second plug contact body holding a plurality of second plug contacts, a second plug contact housing into which the second plug contact body is inserted, and a one-piece sealing ring radially enclosing the second plug contact housing, wherein a first part of the sealing ring is arranged radially between the second plug contact body and the second plug contact housing, and a second part rests axially on the second plug contact housing for, in particular, moisture-tight sealing with respect to the pot housing and / or the first plug connector. The sealing ring is preferably made of an elastomer, in particular rubber or a thermoplastic elastomer, and / or plastic.The first part and the second part can be connected to each other circumferentially or at multiple points. The second part preferably has a circular cross-section, while the first part can have a flat, axially extending cross-section. Preferably, the second connector and / or the first connector has a locking means for locking the connectors together.

[0022] According to a further preferred development of the method or the submersible motor pump, the first connector comprises ten axially symmetrically arranged first plug contacts and / or the second connector has a strain relief for a cable of the second connector that can be secured by means of cable ties and / or binding wire. The first connector, the second connector, and / or the second plug contact housing can be manufactured by injection molding, with the strain relief preferably being molded onto the second plug contact housing.

[0023] According to another preferred embodiment of the method or the submersible motor pump, the pot housing is made of sheet metal, in particular sheet metal and / or stainless steel. According to another preferred embodiment of the method or the submersible motor pump, the top housing has a cover, and the connector opening is provided in the cover. The cover can be removable and / or is preferably connected to the pot housing in a moisture-tight manner.

[0024] According to another preferred development of the method or the submersible motor pump, an impeller driven by the motor and arranged on the base surface is provided. The impeller is preferably arranged in a pump housing located below the pot housing, wherein the pump housing can be fixedly screwed to the pot housing. Feet on which the submersible motor pump can be placed can be provided on the pump housing.

[0025] According to a preferred development, the method comprises the step of gripping the first connector using a tool. The tool can be pliers, in particular needle-nose pliers. Preferably, the tips of the pliers are inserted through the connector opening into the housing to grip the first connector and then guide it axially toward the housing for removal.

[0026] The problem is further solved by a wastewater lifting station comprising a submersible motor pump as described above. A wastewater lifting station, also called a lifting unit, is generally understood to be a pumping system that lifts wastewater using a submersible motor pump to allow it to drain away. The wastewater lifting station can be designed as an automatic system that safely drains wastewater that accumulates below a backflow level or pumps it to a higher level. Wastewater lifting stations are often installed at the lowest point of a basement, pit, or shaft, especially a sump, and are regularly connected to the public sewer system, for example, to keep a building's drainage system operational. Short description of the drawings

[0027] The invention is explained in more detail below with reference to the attached drawings using preferred embodiments.

[0028] The drawings show Fig. 1 is a schematic perspective view of a submersible motor pump with a pot housing according to a preferred embodiment of the invention, Fig. 2 is a schematic perspective view of a cover surface of the pot housing with a first plug connector locked thereto according to the preferred embodiment of the invention, Fig. 3 is a schematic perspective view of the first plug connector with a stator of the submersible motor pump according to the preferred embodiment of the invention, Fig. 4 is a sectional view through the pot housing with the first plug connector and a second plug connector connected thereto according to the preferred embodiment of the invention, Fig. 5 is a schematic perspective view of the second plug connector according to the preferred embodiment of the invention, Fig. 6 is a sectional view through the second plug connector according to the preferred embodiment of the invention,7 is a schematic perspective view of the first plug connector according to the preferred embodiment of the invention, Fig. 8 is a schematic perspective view of the second plug connector according to the preferred embodiment of the invention, Fig. 9 is a schematic perspective view of a second plug contact housing of the second plug connector according to the preferred embodiment of the invention, Fig. 10 is a schematic perspective view of a sealing ring of the second plug connector, Fig. 11 is a schematic partial sectional view of the submersible motor pump with the pot housing according to a further preferred embodiment of the invention, and Fig. 12 is a schematic partial sectional view of part of the second plug connector of the submersible motor pump. Fig. 11 according to the further preferred embodiment of the invention. Detailed description of the implementation examples

[0029] Fig. 1shows a schematic perspective view of a submersible motor pump 1 with a pot housing 2 according to a preferred embodiment of the invention. The submersible motor pump 1 is designed as a dirty water and / or wastewater submersible pump and can be used for pumping contaminated water, for example, from floods, in flooded excavations, in laundry rooms, in muddy pits, in biotopes and / or garden ponds, from drainage shafts, and in cellars, and in particular for pumping water with various degrees of contamination, such as stones, mud, debris, or feces.

[0030] The cylindrical pot housing 2, made of sheet metal, has an open base surface, to which a pump housing 3 is connected, with an impeller (not shown in the figure) provided therein for conveying the dirty water and / or wastewater. A cover surface 4, axially opposite the base surface, can be seen in more detail in Fig. 2, is closed except for a connector opening 5 provided therein. Thus, between the base surface, the cover surface 4 and a lateral surface of the pot housing 2, an interior space 6, indicated in Fig. 4 , trained.

[0031] A motor with a rotor (not shown in detail) for driving the impeller is provided in the interior 6 of the pot housing 2. The motor has a Fig. 3 shown cylindrical stator 7 with a plurality of windings 8. The ends of the windings 8, designed as strands, are led out of the stator 7 on a cover surface and are connected to a Fig. 7 The stator 7 is arranged in the interior 6 of the pot housing 2 in such a way that the cover surface of the stator 7 with the first plug connector 9 connected to the ends of the windings 8 is oriented towards the closed cover surface 4 of the pot housing 2, as can be seen in principle from Fig. 4 visible.

[0032] As mentioned in Fig.7 The first plug connector 9 shown in more detail is designed as a male connector with ten first plug contacts 10, which are arranged axially symmetrically in a first plug contact body made of plastic and form a first plug face of the first plug connector 9. The first plug contacts 10 are used for the three phases L1, L2 and L3, for earth, for two winding protection contacts, for a switchgear protection contact and for corner points U1, V1 and W1 of a delta connection for the motor. The first plug connector 9 further has a radially resilient locking tab 11, which extends axially away from one edge of the first plug connector 9 and is axially parallel to the first plug contacts 10.

[0033] If the stator 7 is now provided in the interior 6, for example, after placing the pot housing 2 onto the stator 7 or after inserting the stator 7 into the interior 6, the first connector 9 is expediently first inserted into a holding device 12 assigned to the connector opening 5. The holding device 12 is designed as a shelf and is provided axially below the plug connection opening 5. In this way, the first connector 9 can be grasped in the holding device 12 from outside the pot housing 2 through the connector opening 5 with a tool, for example needle-nose pliers, and inserted axially outwards into the plug connection opening 5. Since the connector opening 5 corresponds in its non-corresponding inner diameter to the non-corresponding outer diameter of the first connector 9, the locking tab 11 engages with the pot housing 2, as shown in Fig. 2shown. Thus, the first connector 9 is connected to the pot housing 2 in a force-locking and form-locking manner.

[0034] As shown in detail Fig. 7As can be seen, the locking tab 11 has a radially opening locking tab opening 13. A gripping tab 14 with a radially opening gripping tab opening 15 provided thereon extends away from the first plug contact body, parallel to the axis of the locking tab 11. To grip the locking tab 11 and the gripping tab 14, the tips of the needle-nose pliers are expediently inserted into the locking tab opening 13 and the gripping tab opening 15, so that the locking tab 11 can be radially compressed to insert the first plug connector 9 into the plug connector opening 5. In addition to the locking tab 11, the first plug connector 9 has two further locking tabs 16, which also extend away from the edge of the first plug connector 9, parallel to the axis thereof, the locking tab 11 and the two further locking tabs 16 being arranged at approximately regular intervals around the first plug face.

[0035] After locking the first connector 9 with the pot housing 2, a second connector 17 can be inserted as shown in Fig. 4 shown on the first connector 9. The second connector 17 is designed as a female connector and has, corresponding to the first connector 9 and as shown Fig. 8 As can be seen, a second plug contact body 19 made of plastic, which holds a plurality of second plug contacts 18 and forms a second plug face. A radially extending filler opening 20 is provided on the plug face side, into which resin can be poured as a potting material for potting the second plug contacts 18 with strands of a cable connected thereto into the second plug contact body 19. Axially offset from the filler opening 20, i.e., away from the first plug connector 9, a radially opening and axially extending overflow volume 21 is provided, in which excess potting material can be collected.

[0036] Fig. 9 shows a second plug contact housing 22 made of plastic, into which the second plug contact body 17 is inserted on one side and into which the cable is inserted on an opposite side. A sealing ring 23 is provided between the second plug contact housing 22 and the second connector 17, as shown in detail in Fig. 10 shown. A first part of the sealing ring 23 lies radially between the second plug contact body 19 and the second plug contact housing 22, as can be seen from Fig. 4 and 6 A second part of the sealing ring 23 is located, as can be seen Fig. 5 axially on the second plug contact housing 22. In the connected state of the first connector 9 with the second connector, as can be seen from Fig. 4 As can be seen, the second part of the sealing ring 23 seals the plug contact housing 22 against the pot housing 2.

[0037] The second plug contact housing 22 has a strain relief 24 for the cable of the first connector on the cable side, on the side facing away from the second mating face. The strain relief 24 is designed as a molded plastic part to which the cable is fixed in place by means of a cable tie.

[0038] Fig. 11 shows a schematic partial sectional view of the submersible motor pump 1 with the pot housing 2 according to another preferred embodiment of the invention, wherein the pot housing 2 is made of gray cast iron. In contrast to the previously described embodiment, the connector opening 5 is arranged in the outer surface of the pot housing 2 and pivoted relative to the axis of the pot housing 2.

[0039] While in Fig. 11 the first connector 9 with the second connector 17 is shown, Fig. 2a sectional view of part of the second connector 17. The second connector 17 has a metal sleeve 25 extending axially from the second plug face in an extension of the second plug contact body 19.

[0040] The second plug contact body 19 has a radially outwardly extending plastic locking lug 26. The metal sleeve 25 has a corresponding radially outwardly extending locking recess 27 and a radially inwardly extending metal locking lug 28, which is axially spaced from the locking recess 27. Thus, upon axial insertion of the second plug contact body 19 into the metal sleeve 25, the metal locking lug 28 initially presses the plastic locking lug 26 radially inward, whereby the second plug contact body 19 locks into the second plug contact body 19 after the plastic locking lug 26 has locked into the locking recess 27. List of reference symbols

[0041] Submersible motor pump 1 Pot housing 2 Pump housing 3 Cover area 4 Connector opening 5 Interior 6 stator 7 Windings, especially strands 8 First connector 9 First plug contacts 10 locking tab 11 Holding device 12 Snap-in tab opening 13 Grab tab 14 Grab bottle opening 15 Additional locking tab 16 Second connector 17 Second plug contacts 18 Second plug contact body 19 Filling opening 20 Overflow volume 21 Second plug contact housing 22 Sealing ring 23 Strain relief 24 metal sleeve 25 Plastic locking lug 26 Recess 27 Metal locking lug 28

Claims

1. A method for producing a submersible motor-driven pump (1), comprising a cylinder-like pot housing (2), which forms an interior space (6) between an open base surface and a top surface (4) axially opposite the base surface and comprises a connector opening (5) provided in the pot housing (2), a motor that is provided in the interior space (6) and comprises a cylinder-like stator (7) comprising a plurality of windings (8) and a first connector (9) that is connected to ends of the windings (8) and is provided with at least one radially resilient latching tab (11), and comprising the steps of: gripping the first connector (9) from outside the pot housing (2) through the connector opening (5), inserting the first connector (9) from the interior space (6) into the connector opening (5), and latching the at least one latching tab (11) to the pot housing (2).

2. A submersible motor-driven pump (1) comprising a cylinder-like pot housing (2), which forms an interior space (6) between an open base surface and a top surface (4) axially opposite the base surface and comprises a connector opening (5) provided in the pot housing (2), and a motor that is provided in the interior space (6) and comprises a cylinder-like stator (7) comprising a plurality of windings (8) and a first connector (9) that is connected to ends of the windings (8) and is provided with at least one latching tab (11), wherein the first connector (9) can be inserted into the connector opening (5) from outside the pot housing (2) through the connector opening (5) from the interior space (6) in order to latch the at least one latching tab (11) to the pot housing (2).

3. The method or submersible motor-driven pump (1) according to any one of the preceding claims, wherein the first connector (9) comprises a radially fixed gripping tab (14), such that, by gripping the gripping tab (14) and the latching tab (11), in particular by means of a tool, the at least one latching tab (11) can be radially compressed in order to insert the first connector (9) into the connector opening (5).

4. The method or submersible motor-driven pump (1) according to any one of the preceding claims, comprising a holding device (12) for the first connector (9), which holding device is arranged in the interior space (6) and is associated with the connector opening (5), wherein the first connector (9) is arranged in the holding device (12) for gripping the first connector (9).

5. The method or submersible motor-driven pump (1) according to any one of the preceding claims, wherein the first connector (9) has a non-rotationally symmetrical cross section and the connector opening (5) has a cross section corresponding to the first connector (9) or a non-corresponding cross section, such that the first connector (9) is secured or not secured against rotation in the connector opening (5).

6. The method or submersible motor-driven pump (1) according to any one of the preceding claims, wherein the connector opening (5) is provided in the top surface (4) or in an outer surface of the pot housing (2).

7. The method or submersible motor-driven pump (1) according to any one of the preceding claims, comprising a second connector (17) that can be connected to the first connector (9) and comprises a metal sleeve (25) and a second plug contact body (19) that is made of plastics material and holds a plurality of second plug contacts (18), wherein the second plug contact body (19) comprises a radially outwardly extending latching lug made of plastics material (26) and the metal sleeve (25) comprises a corresponding radially outwardly extending latching recess (27) and a radially inwardly extending latching lug made of metal (28) such that, when the second plug contact body (19) is inserted into the metal sleeve, the latching lug made of metal (28) first presses the latching lug made of plastics material (26) radially inwards and, after the latching lug made of plastics material (26) latches to the latching recess (27), latches into the second plug contact body (19).

8. The method or submersible motor-driven pump (1) according to any one of the preceding claims, comprising a second connector (17) that can be connected to the first connector (9) and comprises a second plug contact body (19) that holds a plurality of second plug contacts (18) and forms a second connector face, wherein the second connector (17) comprises, on the connector-face side, a filling opening (20) for encapsulating the plurality of second plug contacts (18) in the second plug contact body (19) with encapsulant and an overflow volume (21), which is offset axially with respect to the filling opening (20), for collecting excess encapsulant emerging from the filling opening (20).

9. The method or submersible motor-driven pump (1) according to any one of the preceding claims, comprising a second connector (17) that can be connected to the first connector (9) and comprises a second plug contact body (19) that holds a plurality of second plug contacts (18), a second plug contact housing (22), into which the second plug contact body (19) is inserted, and an integrally formed sealing ring (23) radially surrounding the second plug contact housing (22), wherein a first part of the sealing ring (23) is arranged radially between the second plug contact body (19) and the second plug contact housing (22) and the second part rests axially on the second plug contact housing (22) for sealing with respect to the pot housing (2) and / or the first connector (9).

10. The method or submersible motor-driven pump (1) according to any one of the preceding claims, wherein the first connector (9) comprises ten axially symmetrically arranged first plug contacts (10) and / or the second connector (9) comprises a strain relief device (24), which can be fixed by means of cable ties and / or binding wire, for a cable of the second connector (9).

11. The method or submersible motor-driven pump (1) according to any one of the preceding claims, wherein the pot housing (2) is made of sheet metal.

12. The method or submersible motor-driven pump (1) according to any one of the preceding claims, wherein the pot housing comprises a cover and the connector opening (5) is provided in the cover.

13. The method or submersible motor-driven pump (1) according to any one of the preceding claims, comprising an impeller that is driven by the motor and is provided on the base surface.

14. The method according to any one of the preceding claims, comprising the step of: gripping the first connector (9) by means of a tool.

15. A wastewater pumping station comprising a submersible motor-driven pump (1) according to any one of the preceding submersible motor-driven pump claims.