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EP-4735767-A1 - ECCENTRIC SCREW PUMP, METERING SYSTEM AND METHOD

EP4735767A1EP 4735767 A1EP4735767 A1EP 4735767A1EP-4735767-A1

Abstract

An eccentric screw pump (18) for metering a medium (M, M1, M2), having at least two stators (19), at least two rotary units (8), wherein, during operation of the eccentric screw pump (18) for metering the medium (M, M1, M2), each of the at least two rotary units (8) interacts with one of the at least two stators (19), a pump housing (15), to which the at least two stators (19) are attached and through which at least portions of the at least two rotary units (8) run, wherein the pump housing (15) has a tank portion (16) for receiving the medium (M, M1, M2), and at least two seal means (30) for sealing the at least two rotary units (8) with respect to the tank portion (16), wherein the at least two seal means (30) are arranged outside the tank portion (16).

Inventors

  • KAMHUBER, Franz
  • Göller, Thomas
  • WIDDERICH, Korbinian

Assignees

  • ViscoTec Pumpen- und Dosiertechnik GmbH

Dates

Publication Date
20260506
Application Date
20240724

Claims (15)

  1. 1. Eccentric screw pump (1B) for metering a medium (M, Ml, M2), comprising at least two stators (19), at least two rotor units (8), wherein during operation of the eccentric screw pump (1B) for metering the medium (M, Ml, M2) each of the at least two rotor units (8) interacts with one of the at least two stators (19), a pump housing (15) to which the at least two stators (19) are attached and through which the at least two rotor units (8) run at least in sections, wherein the pump housing (15) has a tank section (16) for receiving the medium (M, Ml, M2), and at least two sealing devices (30) for sealing the at least two rotor units (8) relative to the tank section (16), wherein the at least two sealing devices (30) are arranged outside the tank section (16).
  2. 2. Eccentric screw pump according to claim 1, comprising a fill level sensor (38) which is designed to continuously detect a fill level (F) of the medium (M, M1, M2) within the tank section (16).
  3. 3. Eccentric screw pump according to claim 1 or 2, wherein the tank section (16) is formed by a cross-sectional enlargement of the pump housing (15), and/or wherein an inner diameter (D) of the tank section (16) is larger than a respective outer diameter (d) of the at least two stators (19), and wherein the inner diameter (D) is in particular at least twice as large as the outer diameter (d).
  4. 4. Eccentric screw pump according to one of claims 1 - 3, wherein the pump housing (15) has a flange section (18) and a transition section (17) connecting the tank section (16) and the flange section (18), wherein the transition section (17) is funnel-shaped, and wherein the at least two stators (19) are each attached in particular to the flange section (18).
  5. 5. Eccentric screw pump according to one of claims 1 - 4, wherein the eccentric screw pump (1B) has an inlet (36) projecting into the tank section (16) for filling the medium (M, M1, M2) below the surface.
  6. 6. Eccentric screw pump according to one of claims 1 - 5, comprising a sealing housing (24) connected to the pump housing (15), wherein each of the at least two sealing devices (30) is accommodated in the sealing housing (24), and/or wherein the at least two sealing devices (30) each have at least one sealing lip (34, 35), wherein the at least two rotor units (8) each have a protective sleeve (14), and wherein the at least one sealing lip (34, 35) rests against the protective sleeve (14).
  7. 7. Eccentric screw pump according to one of claims 1 - 6, comprising a drive (2) for driving each of the at least two rotor units (8), wherein the drive (2) is coupled to one of the at least two rotor units (8) by means of a coupling star (4), and wherein the coupling star (4) is made of a heat-insulating material.
  8. 8. Eccentric screw pump according to one of claims 1 - 7, comprising a temperature sensor (41) for monitoring the temperature of each of the at least two sealing devices (30).
  9. 9. Eccentric screw pump according to one of claims 1 - 8, comprising a thermal insulation and/or heating sleeve (61) which encloses the pump housing (15) at least in sections.
  10. 10. Eccentric screw pump according to one of claims 1 - 9, comprising an overfill sensor (40) for monitoring a maximum fill level (F) of the medium (M, M1, M2) in the tank section (16).
  11. 11. Eccentric screw pump according to one of claims 1 - 10, comprising a valve (39A, 39B) for ventilating or de-ventilating the tank section (16), for applying a vacuum to the tank section (16) and/or for supplying the tank section (16) with a process gas, such as nitrogen, argon or the like.
  12. 12. Eccentric screw pump according to one of claims 1 - 11, comprising an end piece unit (42) with a temperature-pressure sensor (46) attached to each of the at least two stators (19).
  13. 13. Eccentric screw pump according to one of claims 1 - 12, wherein the pump housing (15) has a plurality of pump housing modules (74, 75, 76, 77) detachably connected to one another.
  14. 14. Dosing system (47) for dosing a medium (M, M1, M2), comprising at least two eccentric screw pumps (1B) according to one of the claims 1 - 13, a ring line (49) to which the at least two eccentric screw pumps (1B) are connected and through which the medium (M, Ml, M2) flows continuously, and a medium supply (48) for supplying the ring line (49) with the medium (M, Ml, M2).
  15. 15. Method for operating an eccentric screw pump (1B) according to one of claims 1 - 13, with the following steps: a) dosing (Sl) of the medium (M, Ml, M2) with the aid of the eccentric screw pump (1B), and b) maintaining (S2) a fill level (F) of the medium (M, Ml, M2) in the tank section (16) by supplying the medium (M, Ml, M2) to the tank section (16) during step a).

Description

PROCESSING SCREW PUMP, DOSING SYSTEM AND PROCESS The present invention relates to an eccentric screw pump, a dosing system with at least two such eccentric screw pumps and a method for operating such an eccentric screw pump. Impregnating the rotor and stator is an important process in the manufacture of electric motors. The demand for long-lasting electric motors with the highest power density and low noise emissions is increasing, particularly with the electrification of the drive train in the automotive sector. The quality of the insulation in electric drives determines, among other things, the longevity and efficiency of the electric drive. The round or flat wire required for the coil is first coated with a layer of varnish to ensure electrical insulation. A sliding layer is then applied to the round wire, which makes winding easier. After the round wire has been wound or the flat wire has been joined, impregnation is carried out to create secondary insulation. To do this, a casting compound, for example in the form of an impregnating resin, is applied to the wire to fill cavities within the windings or between the winding and the laminated core and to displace air bubbles. It is important that the casting compound has a low viscosity and is continuously dosed without air pockets. This is the only way for the casting compound to penetrate optimally into all cavities. The temperature during processing of the casting compound is a process-determining factor that - in conjunction with the component - must be matched to the respective material. Secondary insulation increases the durability of electrical rotating machines, especially electric motors and generators. By closing and sealing the cavities, vibrations are minimized. These could Otherwise, short circuits and noise will result. The mechanical resistance is thus increased. As already mentioned, the impregnation also serves the purpose of displacing air pockets. Air is a good thermal insulator and would hinder the desired heat dissipation. If these air pockets are filled with the casting compound, a complete thermal coupling is created between the laminated core and the windings. The heat can be optimally dissipated. In high-voltage applications, air can also cause electrical breakdown. Thanks to the encapsulation with the potting compound, the electrical insulation within the windings is further improved and short circuits caused by damage to the paint layer can be prevented. The potting compound also offers protection against chemical influences, moisture and dust. Overall, the impregnation can achieve a longer service life and improved performance. According to internal company knowledge, different impregnation methods can be used. Firstly, the component to be impregnated can be immersed in the casting compound. The preheated component is immersed in a casting compound basin at a defined speed. The casting compound can gel as the component is heated during the immersion process. This in turn can reduce drip losses. In so-called roll immersion, the component also rotates during and after the immersion process. The component is then cured in a heating section. Immersion can be adapted to any size, low investment costs result if rotation of the component is not required, and immersion is easily scalable for large volumes. Secondly, vacuum casting is possible using the casting compound. The stator is clamped into a mold into which the casting compound flows and slowly rises upwards. A sealing core is placed in the middle of the stator to ensure vacuum tightness. The entire mold or component is evacuated. The evacuated casting compound is introduced under vacuum. Air pockets and cavities are reliably cast and copper windings, undercuts and gaps are completely filled with the casting compound. After the casting compound has hardened, the sealing core is removed again. The advantage of vacuum casting is that cavities are avoided and the impregnation quality is high. The use of two-component casting compounds is also possible. Thirdly, the potting compound can be trickled. In trickling, the component or stator is clamped onto a mandrel and continuously rotated around its own axis in a horizontal position. The component is heated by oven heating or by induction. During rotation, the low-viscosity potting compound is trickled on through several nozzles at different positions using a dosing system. The capillary effect causes the potting compound to penetrate the windings and spread evenly throughout the stator. This produces a high-quality impregnation result. Trickling is particularly suitable if only certain areas of the component are to be wetted with the potting compound. The advantages of trickling are that the dosing quantity and the dosing flow can be precisely regulated. This enables low consumption of the casting compound with a high filling level. Trickling is ideal for the use of two-component casting compounds. This enables rapid curing and/or c