BOREHOLE PUMP

Description

Technical field

[0001] The invention relates to a borehole pump with an axially extending stator, an axially extending rotor arranged in the stator and radially enclosed by the stator and a plurality of coils, each with a first axial coil end and an opposite second axial coil end, wherein a plurality of axially extending teeth facing the rotor, each with a first axial tooth end and an opposite second axial tooth end, and radially recessed axially extending grooves receiving the coils are formed on the stator.

[0002] The invention also relates to a method for applying a plurality of coils, each having a first axial coil end and an opposite second axial coil end, to an axially extending stator of a borehole pump with an axially extending rotor arranged in the stator and radially enclosed by the stator, wherein a plurality of axially extending teeth facing the rotor, each having a first axial tooth end and an opposite second axial tooth end, and axially extending grooves for receiving the coils, which grooves are formed alternately on the stator. Background of the invention

[0003] Borehole pumps are known from the state of the art and are used to pump a fluid such as water or petroleum, particularly from underground deposits. Such borehole pumps are often lowered into a borehole until they are immersed in the fluid or a fluid-bearing soil layer, where they remain.

[0004] The manufacture of such borehole pumps, especially the coils of their motors, is complex and therefore costly, which is especially true when expensive insulated submarine cables are used for the coil windings. Due to the limited space available for borehole pumps for use in boreholes with small diameters, it takes up to 16 hours to manufacture the coils for a borehole pump. Since insulated submarine cables become sticky at higher temperatures, inserting the windings into a borehole pump stator is time-consuming and often leads to errors. Repairing a defective winding or coil is often not possible due to the limited space available. Likewise, repair during operation is rarely possible due to the installation in the borehole.

[0005] US 2006 / 175064 A1 describes an electric submersible pump comprising an AC permanent magnet motor with three or more phases and a drive circuit for supplying different drive signals to all phases of the motor simultaneously.

[0006] JP 2013 183543 A describes a winding device comprising a line-side coil former for forming a planned line-side coil end and an anti-line-side coil former for forming a planned line-side coil end. Description of the invention

[0007] Based on this situation, it is an object of the present invention to provide a borehole pump and a corresponding manufacturing method, with which a borehole pump can be manufactured and repaired more easily and cost-effectively.

[0008] The object of the invention is achieved by the features of the independent claims. Advantageous embodiments are specified in the subclaims.

[0009] Accordingly, the object is achieved by a borehole pump with an axially extending stator, an axially extending rotor arranged in the stator and radially enclosed by the stator, and a plurality of coils each having a first axial coil end and an opposite second axial coil end, wherein on the stator, a plurality of axially extending teeth facing the rotor are alternately formed, each having a first axial tooth end and an opposite second axial tooth end, and axially extending grooves which are radially recessed between two adjacent teeth and which receive the coils, the respective second axial coil end is bent in the region of the second axial coil end and is thereby arranged radially offset from the first axial coil end towards the rotor in order to radially enclose at least one tooth, and the respective first axial coil end axially encloses at least one first axial tooth end and the respective second axial coil end axially encloses at least one second axial tooth end.

[0010] In an alternative embodiment, the object is achieved by a motor, in particular for a pump, having an axially extending stator, an axially extending rotor arranged in the stator and radially enclosed by the stator, and a plurality of coils, each having a first axial coil end and an opposite second axial coil end, wherein on the stator, a plurality of axially extending teeth facing the rotor are alternately formed, each having a first axial tooth end and an opposite second axial tooth end, and axially extending grooves which are radially recessed between two adjacent teeth and which receive the coils, the respective second axial coil end is bent in the region of the second axial coil end and is thereby arranged radially offset from the first axial coil end towards the rotor in order to radially enclose at least one tooth, and the respective first axial coil end axially encloses at least one first axial tooth end and the respective second axial coil end axially encloses at least one second axial tooth end.

[0011] A key aspect of the proposed borehole pump is that the coils can be pushed axially onto the stator and, accordingly, pushed off the stator again in an axial direction for removal. In this respect, it is also possible to manufacture the coils outside the stator and only attach them to the stator after the winding has been completed. This not only significantly reduces the manufacturing time for the borehole pump, but also makes it possible to replace defective coils during operation. Because the second axial coil end is arranged radially offset to enclose at least one tooth, the wound coil can be pushed into two slots with the second axial coil end first until the first axial coil end comes to rest against the first axial tooth end, and can then be removed from the stator again.

[0012] The borehole pump, also known as a water motor pump or vertical pump, can be used in narrow boreholes or wells with a small inner diameter. For this purpose, the borehole pump preferably has a cylindrical housing or is designed in the shape of a cylinder, which cylinder can be inserted into the borehole. Accordingly, the stator is also preferably designed in the manner of a cylinder. The rotor preferably drives an impeller for pumping a fluid. In principle, different fluids such as water, wastewater or crude oil can be pumped with the borehole pump. The coils preferably have a plurality of turns and / or have a rectangular shape in plan view, extending between the first axial coil end and the second axial coil end. The stator or the borehole pump can have a preferably circular inner diameter and / or an inner diameter of 10, 20, 30, 40 or 50 cm.Accordingly, the teeth on the inside of the stator can preferably form a circular diameter. The borehole pump can be designed as a centrifugal pump.

[0013] The teeth preferably extend completely between both opposite axial tooth ends. Turns of two coils are preferably arranged in a slot. For this purpose, the slots preferably recess radially with respect to the rotor. The slots are preferably almost completely, preferably completely, filled by the turns. The second coil end is preferably bent towards the rotor in such a way that at least one tooth can be enclosed by the bend when the coil is arranged in the slots. In other words, the bend preferably has a negative shape of the at least one tooth. When the coil, bent or angled in this way, is pushed onto the at least one tooth, the at least one tooth does not oppose the coil. The turns are preferably made of insulated wire and / or submarine cable. The turns can have a circular, cuboidal, or square cross-section.The coils and / or windings are preferably made of wire, in particular insulating-coated wire, for example, enameled wire, and / or are bent, in particular bent in an L-shape. Further preferably, the windings are not manufactured by casting, for example, they are not cast and / or are manufactured without casting, in particular without casting. The motor is preferably used for a pump, in particular for a centrifugal pump, most preferably as a borehole pump.

[0014] According to a preferred development, the respective first axial coil end and / or the respective second axial coil end is arranged axially outside the slots and / or the teeth and / or the respective second axial coil end is arranged radially outside the slots and / or the teeth. After the coils have been fully inserted into the slots, the second axial coil end preferably lies next to the teeth in an axial plan view. Axially outside the slots and / or the teeth means, in particular, that the teeth, in an axial plan view of the coil, are circumferentially enclosed by the coil.

[0015] According to another preferred embodiment, the respective second axial coil end is bent orthogonally in the direction of the rotor in the region of the second axial coil end. Preferably, the coil has a longitudinal extent between its axial coil ends that is greater than the longitudinal extent of the slots or teeth. The coil can comprise a plurality of turns arranged one above the other and / or next to one another. Accordingly, individual turns can be arranged radially offset by different lengths in the region of the second axial coil end. For example, a turn arranged closer to the rotor in the region of the second axial coil end can be designed to be significantly less radially offset, while a turn arranged further from the rotor, in contrast, can be designed to be more radially offset, so that both turns of the coil can "slide" over the at least one tooth with their second radially offset axial coil ends upon axial insertion into the slots.In axial side view, the coils can have an L-shape.

[0016] According to a preferred development, the first axial coil end and / or the second axial coil end axially contact the at least one first axial tooth end and / or the at least one second tooth end, and / or the respective second axial coil end is arranged to radially contact at least one tooth. "Contacting" in this context can also mean that the coil rests as closely as possible against the tooth.

[0017] According to another preferred embodiment, the slots accommodate the coils with a precise fit and / or the slots have a triangular and / or V-shaped cross-section in the radial direction. Preferably, a plurality of turns of two coils each are provided in each slot, each of which is arranged over a complete axial extent within the slot. Preferably, the coils are provided only within the slots in the region of the stator and do not extend radially beyond the teeth in the direction of the rotor. The plurality of turns are preferably arranged one above the other in the axial direction, in particular, in the case of a triangular and / or V-shaped cross-section of the slots, also triangular and / or V-shaped in side view.

[0018] According to a preferred development, the coils are arranged in an overlapping and / or nested manner in the region of the first axial coil end and / or in the region of the second axial coil end, in particular outside the stator, and / or the coils have a rectangular shape. The borehole pump is preferably designed as a three-phase pump, so that windings of the individual phases can be introduced into the slots one after the other at regular intervals and are arranged in an overlapping and / or nested manner in the region of the first axial coil end and / or in the region of the second axial coil end, in particular outside the stator. The stator preferably has 6, 9, 12 or 15 slots and a corresponding number of teeth or windings. The stator can be surrounded by a housing or designed as the housing of the borehole pump.

[0019] The object of the invention is further achieved by a method for applying a plurality of coils, each having a first axial coil end and an opposite second axial coil end, to an axially extending stator of a borehole pump with an axially extending rotor arranged in the stator and radially enclosed by the stator, wherein a plurality of axially extending teeth facing the rotor, each having a first axial tooth end and an opposite second axial tooth end, and axially extending grooves for receiving the coils are formed alternately on the stator, comprising the steps: Bending the respective second axial coil end in the region of the second axial coil end until the second axial coil end is arranged radially offset from the first axial coil end towards the rotor for radially enclosing at least one tooth, and pushing the respective coil in the axial direction with the bent second axial coil end first into at least two grooves until the respective first axial coil end axially encloses at least one first axial tooth end and the respective second axial coil end axially encloses at least one second axial tooth end.

[0020] In an alternative embodiment, the object is achieved by a method for applying a plurality of coils, each having a first axial coil end and an opposite second axial coil end, to an axially extending stator of a motor, in particular for a pump, with an axially extending rotor arranged in the stator and radially enclosed by the stator, wherein a plurality of axially extending teeth facing the rotor, each having a first axial tooth end and an opposite second axial tooth end, and axially extending grooves for receiving the coils are formed on the stator alternately, comprising the steps: Bending the respective second axial coil end in the region of the second axial coil end until the second axial coil end is arranged radially offset from the first axial coil end towards the rotor for radially enclosing at least one tooth, and pushing the respective coil in the axial direction with the bent second axial coil end first into at least two grooves until the respective first axial coil end axially encloses at least one first axial tooth end and the respective second axial coil end axially encloses at least one second axial tooth end.

[0021] The proposed method allows, on the one hand, the respective coil or all coils together to be inserted into the stator from a transverse side of the stator in a particularly simple manner, namely in particular by inserting them into at least two slots in the axial direction. In contrast to coils known from the prior art, which were either wound into the slots or first inserted into a free area of ​​the stator and then pressed radially outwards into the slots, the proposed method allows the coils to be inserted into the slots directly from the transverse side of the stator. As a result, a defective coil or all coils together can be removed from the stator by axially pushing them out, even if the borehole pump is arranged in a borehole. This is not possible with the designs known from the prior art.When pushed on, the bent second axial coil end preferably slides over at least one tooth, while a non-bent part of the coil slides through the at least two grooves.

[0022] According to a preferred development, the method comprises the step of: winding windings to obtain the bent coil in such a way that, after sliding on, the respective first axial coil end can axially enclose at least one first axial tooth end, the respective second axial coil end can axially enclose at least one second axial tooth end and the respective second axial coil end can enclose at least one tooth radially in the direction of the rotor in the region of the respective second axial tooth end.

[0023] In other words, the winding is preferably carried out such that, in a side view, the bent second axial coil end engages around at least one tooth, particularly in a U-shape. The winding is further preferably carried out such that an axial extension of the coil is greater than, approximately equal to, or equal to the radial extension of the teeth or grooves.

[0024] According to another preferred development, the method comprises the step of: arranging the respective first axial coil end and / or the respective second axial coil end such that the first axial coil end and / or the second axial coil end comes to lie axially outside the grooves and / or the teeth, and / or the respective second axial coil end such that the second axial coil end comes to lie radially outside the grooves and / or the teeth.

[0025] According to a preferred development, the method comprises the step of bending the respective second axial coil end orthogonally in the direction of the rotor.

[0026] Bending is preferably performed such that the second axial coil end is arranged orthogonally to the first axial coil end. Preferably, only a small portion of the coil is bent, so that the coil extends primarily in the axial direction and only in the radial direction with respect to the at least one tooth.

[0027] According to another preferred development, the method comprises the step of arranging the coils in the region of the first axial coil end and / or in the region of the second axial coil end in an overlapping and / or nested manner and / or in a rectangular shape.

[0028] According to a preferred development, the method comprises the step of laminating the bent coil in a mold to obtain the bent coil.

[0029] Further embodiments and / or advantages of the method will become apparent to those skilled in the art by analogy with the previously described borehole pump. The statements regarding the borehole pump apply analogously to the motor. Short description of the drawings

[0030] The invention is explained in more detail below with reference to the accompanying drawings using a preferred embodiment.

[0031] The drawings show Fig. 1 shows a stator of a borehole pump with a plurality of teeth, each of which has a coil mounted thereon, in a perspective view of a first axial coil end according to a preferred embodiment, Fig. 2 shows the stator of the borehole pump according to Fig. 1 in a perspective view of an opposite second axial coil end, Fig. 3 the stator according to Fig. 1 and 2in a respective side view of the first axial coil end and the second axial coil end, and Fig. 4 a coil according to Figs. 1 to 3 in a perspective view. Detailed description of the implementation examples

[0032] Fig. 1 shows a stator 1 of a borehole pump with a plurality of teeth 2, to each of which a coil 3 is applied, in a perspective view of a first axial coil end 4 according to a preferred embodiment. Fig. 2 shows the stator according to Fig. 1 in a perspective view of an opposite second axial coil end 5. Fig. 3 shows the stator 1 below in side view of the first axial coil end 4 and above in side view of the second axial coil end 5. Finally, Fig. 4 a coil 3 in a perspective view.

[0033] The Figs. 1 to 3The borehole pump shown serves to pump a fluid in a borehole (not shown) into which the borehole pump is lowered. As a rule, the inner diameter of the borehole is only slightly larger than or equal to the outer diameter of the borehole pump or the stator 1. The cylindrical stator 1 extends in the axial direction within the borehole pump. Radially enclosed by the stator 1 and thus arranged within it is a rotor 6, which also extends axially; not shown in the figures and in Fig. 1 by a line 6 and in Fig. 3 indicated by a circle 6.

[0034] A plurality of teeth 2 extend from the outer surface of the stator 1 in the direction of the rotor 6. The teeth 2 each have a cuboid shape, between which triangular grooves 7 are formed in side view, as can be seen particularly well in Fig. 3can be seen. In each slot 7, windings of two adjacent coils 3 are arranged, for which purpose the slots 7 and the windings are each precisely dimensioned. Likewise, the axially extending slots 7, which radially recede between two adjacent teeth 2, can have a cuboid shape, while the teeth 2 are triangular in side view.

[0035] The teeth 2 each have a first axial tooth end 8 and an opposite second axial tooth end 9. The respective first axial coil end 4 is guided around a respective first axial tooth end 8 axially outside the respective tooth 2 or the respective groove 7, as can be seen from Fig. 1 and 3 can be seen below. In other words, the respective first axial coil end 4 does not project beyond the respective tooth 2 in the radial direction towards the rotor 6, but rather projects beyond the groove 7 axially.

[0036] In contrast, the respective second axial coil end 5 is orthogonally bent in the region of the second axial coil end 9 and extends radially towards the rotor 6 in such a way that the bent second axial coil end 5 surrounds the respective tooth 2, in side view as in Fig. 3 shown above, radially projects beyond, but is arranged axially next to the second axial tooth end 9 and thus encloses the second axial tooth end 9 axially outside the respective tooth 2 or the respective groove 7, in the perspective view in Fig. 2 shown. In other words, the respective second axial coil end 5 is bent in the region of the second axial coil end 5 and is thus arranged radially offset from the first axial coil end 4 towards the rotor 6 to radially enclose at least one tooth 2.

[0037] To manufacture the borehole pump, the respective second axial coil end 5 is bent orthogonally in the region of the second axial coil end 5 until the second axial coil end 5 is arranged radially offset from the first axial coil end 4 towards the rotor 6 to radially enclose at least one tooth 2. Subsequently, the respective coil 2 is axially inserted in the axial direction with the bent second axial coil end 5 first into at least two grooves 7 until the respective first axial coil end 4 axially encloses at least one first axial tooth end 8 and the respective second axial coil end 5 axially encloses at least one second axial tooth end 9.

[0038] Accordingly, the coil 2 pushed onto the stator 1 in this way can be pushed axially out of the stator 1 or the slots 7 in the opposite direction, for example in order to replace a defective coil 2.

[0039] To produce the as in Fig. 4In the coil 3 shown which can be inserted axially into the stator 1, a plurality of windings are wound in such a way that, after being pushed on, the respective first axial coil end 4 can axially enclose at least one first axial tooth end 8, the respective second axial coil end 5 can axially enclose at least one second axial tooth end 9, and the respective second axial coil end 5 can enclose at least one tooth 2 in the direction of the rotor 6 in the region of the respective second axial tooth end 9. In other words, the windings are wound in a rectangular shape, with a U-shaped end being bent orthogonally with respect to the remaining part of the rectangle.

[0040] The windings can be fixed using a forming jig and an enameled wire. A needle winder can also be used to fix the windings. The coil 3 bent in this way is then laminated in a casting mold (not shown). The process is repeated for each coil 3. To ensure uniform insulation, spacers made of potting material and / or a bandage in the form of a tape can be used. Although not shown in the figures, the coils 3 can each have a plurality of windings overlapping and / or nested in the region of the first axial coil end 4 and in the region of the second axial coil end 5.

[0041] The above-described embodiments of the borehole pump apply analogously to a motor. The described embodiments are merely examples that can be modified and / or supplemented in a variety of ways within the scope of the claims. Each feature described for a specific embodiment can be used independently or in combination with other features in any other embodiment. Each feature described for an embodiment of a specific category can also be used correspondingly in an embodiment of a different category. List of reference symbols

[0042] stator 1 Tooth 2 Sink 3 First axial coil end 4 Second axial coil end 5 rotor 6 Groove 7 First axial tooth end 8 Second axial tooth end 9

Claims

1. A downhole pump comprising an axially extending stator (1), an axially extending rotor (6), which is disposed in the stator (6) and is radially surrounded by the stator (1), and a plurality of coils (3) each with a first axial coil end (4) and an opposite, second axial coil end (5), wherein a plurality of axially extending teeth (2), which face the rotor (6) and each have a first axial tooth end (8) and an opposite, second axial tooth end (9), and axially extending grooves (7), which are set back radially between two adjacent teeth (2) and receive the coils (3), are formed in alternation on the stator (1), the respective first axial coil end (4) axially surrounds at least one first axial tooth end (8) and the respective second axial coil end (5) axially surrounds at least one second axial tooth end (9), characterised in that the respective second axial coil end (5) is bent in the region of the second axial coil end (5) and thus is disposed radially offset relative to the first axial coil end (4) towards the rotor (6) to radially surround at least one tooth (2).

2. The downhole pump according to the preceding claim, wherein the respective first axial coil end (4) and / or the respective second axial coil end (5) is disposed axially outside the grooves (7) and / or the teeth (2) and / or the respective second axial coil end (5) is disposed radially outside the grooves (7) and / or the teeth (2).

3. The downhole pump according to any one of the preceding claims, wherein the respective second axial coil end (5) is bent in the region of the second axial coil end (5) orthogonally in the direction of the rotor (6).

4. The downhole pump according to any one of the preceding claims, wherein the first axial coil end (4) and / or the second axial coil end (5) surrounds the at least one first axial tooth end (8) and / or the at least one axial second tooth end (9) with axial contact and / or the respective second axial coil end (5) is disposed so as to surround at least one tooth (2) with radial contact.

5. The downhole pump according to any one of the preceding claims, wherein the grooves (7) receive the coils (3) with an accurate fit and / or the grooves (7) have a triangular crosssection in the radial direction.

6. The downhole pump according to any one of the preceding claims, wherein the coils (3), in the region of the first axial coil end (4) and / or in the region of the second axial coil end (5), are disposed overlapping and / or nested one inside the other and / or the coils (3) have a rectangular shape.

7. A method for applying a plurality of coils (3) each with a first axial coil end (4) and an opposite, second axial coil end (5) to an axially extending stator (1) of a downhole pump with an axially extending rotor (6), which is disposed in the stator (1) and is radially surrounded by the stator (1), wherein a plurality of axially extending teeth (2), which face the rotor (6) and each have a first axial tooth end (8) and an opposite, second axial tooth end (9), and axially extending grooves (7) for receiving the coils (3), which grooves are set back radially between two adjacent teeth (2), are formed in alternation on the stator (1), said method having the steps of: bending the respective second axial coil end (5) in the region of the second axial coil end (5) until the second axial coil end (5) is disposed radially offset relative to the first axial coil end (4) towards the rotor (6) to radially surround at least one tooth (2), and sliding the respective coil (3) in the axial direction with the bent second axial coil end (5) at the front into at least two grooves (7) until the respective first axial coil end (4) axially surrounds at least one first axial tooth end (8) and the respective second axial coil end (5) axially surrounds at least one second axial tooth end (9).

8. The method according to the preceding method claim, comprising the step of: winding turns to obtain the bent coil (3) in such a way that, after having been slid on, the respective first axial coil end (4) may axially surround at least one first axial tooth end (8) and the respective second axial coil end (5), in the region of the respective second axial tooth end (9) may radially surround at least one tooth (2) in the direction of the rotor (6).

9. The method according to any one of the preceding method claims, comprising the step of: arranging the respective first axial coil end (4) and / or the respective second axial coil end (5) in such a way that the first axial coil end (4) and / or the second axial coil end (5) comes to lie axially outside the grooves (7) and / or the teeth (2), and / or the respective second axial coil end (5) in such a way that the second axial coil end (5) comes to lie radially outside the grooves (7) and / or the teeth (2).

10. The method according to any one of the preceding method claims, comprising the step of: bending the respective second axial coil end (5) orthogonally in the direction of the rotor (6).

11. The method according to any one of the preceding method claims, comprising the step of: disposing the coils (3) in an overlapping manner and / or nested one inside the other and / or in a rectangular shape in the region of the first axial coil end (4) and / or in the region of the second axial coil end (5).

12. The method according to any one of the preceding method claims, comprising the step of: laminating the bent coil (3) in a casting mould to obtain the bent coil (3).