Method for impregnating, reinforcing or electrically insulating a single- or multi-layer winding body

Abstract

This invention relates to a method for impregnating, strengthening, or electrically insulating a body (7) carrying single or multiple windings, particularly for an electric motor (12), wherein the body carrying the windings is immersed in a multi-component resin system (10), sprayed with the multi-component resin system, or jetted with the multi-component resin system. The invention also relates to an electric motor (12) impregnated, strengthened, or electrically insulating according to this method, particularly an electric motor, generator, or transformer, and to the application of a multi-component resin system (10) for impregnating, strengthening, or electrically insulating an electric motor (12).

Description

Technical Field

[0001] The present invention relates to a method for impregnating, reinforcing or electrically insulating a body carrying a single or multiple winding. Background Technology

[0002] DE 10 2013 017 299 A1 relates to a method for impregnating, reinforcing, or electrically insulating a body carrying a single or multiple windings, particularly for an electric motor / generator or transformer, wherein the body carrying the winding is immersed in or sprayed with resin or paint under the influence of temperature, wherein, before and / or during and / or after immersion or dripping, the body and / or the windings carried by said body are inductively heated in a locally confined space.

[0003] For the impregnation of drip resins mainly comprising electrical windings or other electrical components, motors and the like, EP 0 509 366 A2 proposes to allow artificial drip resin without hardener to overflow separately from the outlet orifice and to provide a jet onto the object to be impregnated with hardener before the jet is sprayed onto the object, spraying the hardener onto the jet surface of the flowing drip resin, for example, such that the drip resin mixed with the hardener is in complete contact with the object to be impregnated and is not connected to any other object.

[0004] The invention in DE 10 2017 001 939 A1 relates to an impregnation apparatus for drip-impregnating a stator or armature of an electric motor with a synthetic resin that hardens upon temperature rise. The impregnation apparatus includes a holding device that can be tilted vertically relative to a horizontal plane, and a drive motor, serving as a rotational drive for the stator (2) or armature, is fixed thereon and connected to the drive shaft of the drive motor in a manner that influences the drive. A clamping device is connected to the drive shaft in a rotationally fixed manner, through which the stator or armature can be detachably connected to the drive shaft. A drip-feeding device guides the synthetic resin to at least one axial end of the windings of the stator or armature. A heating device is also included, through which the windings of the stator or armature can be heated to a drip-feeding temperature and a higher hardening temperature. According to the invention, the heating device includes an electromagnetic inductor arranged coaxially or axially parallel to the stator or armature. The invention also relates to a manufacturing apparatus for drip-impregnating a stator or armature, wherein the impregnation method is integrated.

[0005] DE 1 212 204 B discloses a method for impregnating single-phase and multi-phase stator windings, as well as an apparatus for carrying out the method.

[0006] DE 35 41 235 A1 describes a method for coating or impregnating machine parts, preferably motors, with an insulating varnish. Herein, the machine parts equipped with an insulating system are immersed at room temperature, preferably in the temperature range of 15-40°C, under atmospheric pressure, possibly under vacuum, and possibly under pressure, in a water-soluble varnish having a pH of 7-11, preferably 7-8, and an exudate concentration of 20-150, preferably 35-55 (measured at 20°C and MPa⁻⁴), until no more bubbles are perceived forming on the varnish surface. The machine parts are then removed from the varnish to allow the varnish to drip off, and dried under atmospheric pressure or vacuum at a temperature of 15-80°C, preferably 25-40°C. Subsequently, the varnish is ablated at a temperature specified for the respective varnish.

[0007] JP S57 28319 A discloses impregnating stator windings with a mixture of resin and hardener at ambient temperature. In this disclosure, heating is eliminated for energy efficiency reasons.

[0008] DE 19 48 134 A1 relates to a method for impregnating a structural component with a polymerizable material, wherein the structural component and the impregnating agent are at room temperature of 26°C. The mixture used is also a multi-component resin system.

[0009] The manufacture of an electric motor (e.g., a motor) typically involves multiple manufacturing steps. The stator undergoes an impregnation process, usually achieved by means of a thermosetting impregnation resin, after being drawn into the windings and introduced with phase separators, slot insulation, and slot closure.

[0010] Especially in the field of smaller motors, the impregnation method is often used, in which the motor is drawn into a basin containing resin, also known as a resin basin. Here, smaller motors are, for example, motors with a shaft height of 63 to 160 mm, where the shaft height is the dimension from the center of the motor base to the axis of rotation.

[0011] The subsequent curing process in a hot air oven for several hours is energy-intensive, time-consuming, and often results in cavitation and defects in the cured resin.

[0012] Larger motors, especially those with higher requirements—such as those with shaft heights from 180 to 355 mm—are impregnated using a method in which the stator is preheated by Joule heating and then immersed in a resin bath. While immersed, the stator is also heated by an electric current, causing the resin to gel in the tub and in the winding heads. It is then hardened, again by introducing current into the windings and surface drying by means of ultraviolet radiation. The stator is heated to at least 150°C. Subsequently, the stator, typically weighing hundreds of kilograms, cools very slowly over approximately 24 hours due to its high heat capacity. Further processing (e.g., installing bearing housings) can only be carried out at room temperature, especially due to the coefficient of thermal expansion, thus requiring either active cooling or accepting delays caused by the cooling time of the bearing surfaces at room temperature. Summary of the Invention

[0013] The objective of this invention is to design the manufacture of motors more efficiently in terms of time and energy.

[0014] The solution to this objective is achieved by a method for impregnating, reinforcing, or electrically insulating the body of a single- or multi-layer winding, particularly for motors having the present invention, wherein the body of the winding is immersed in a multi-component resin system or sprayed or jetted with a multi-component resin system.

[0015] In the following text, this method will also be referred to as the impregnation method.

[0016] The solution to this objective is also achieved by the present invention, namely, an electric motor, especially an electric motor, generator or transformer, which is impregnated, strengthened or electrically insulated according to the above method.

[0017] In an advantageous embodiment of the invention, the body of the bearing winding is immersed in a multi-component resin system, sprayed with a multi-component resin system, or sprayed with a multi-component resin system at room temperature.

[0018] The main body is advantageously a motor, generator, or transformer. A motor / generator advantageously has a rotor and a stator.

[0019] The main body can also be a stator or a rotor.

[0020] The main body of the main bearing winding is advantageously immersed in a multi-component resin system or sprayed or sprayed with a multi-component resin system at an ambient temperature of 15 to 25°C, especially 20 to 23°C.

[0021] In an advantageous embodiment of the invention, the body of the carrying winding is preheated to a temperature of 30 to 80°C, particularly 30 to 60°C. Preferably, the body of the carrying winding is preheated to a temperature of 30 to 80°C, particularly 30 to 60°C, by induction.

[0022] The advantage of this is that different ambient temperatures, such as in summer or winter, have no effect on impregnation, reinforcement, or electrical insulation.

[0023] The body of the bearing winding has a defined temperature at the start of the method used for impregnation, reinforcement or electrical insulation, independent of the environment, and is then cooled.

[0024] In this invention, the multi-component resin system has at least two components, wherein the first component is resin and the second component is a curing agent.

[0025] First non-inventive example: The first component (especially the resin) preferably has a viscosity of 2000 to 2500 mPa·s at an ambient temperature of 25°C and a density of 1.13 to 1.17 g / ml at an ambient temperature of 20°C. The second component (especially the hardener) preferably has a viscosity of 40 to 60 mPa·s, especially 50 mPa·s, at an ambient temperature of 25°C and a density of 0.98 to 1.00 g / ml at an ambient temperature of 20°C. The mixing ratio by weight is advantageously 100 parts resin to 20 parts hardener. The mixing ratio by volume is advantageously 100 parts resin to 23 parts hardener. The applicable time of 100 g of the mixture at room temperature is advantageously between 20 and 40 minutes, preferably 30 minutes.

[0026] Second example of the invention: The first component (a resin) has a viscosity of 2400 to 2600 mPa·s and 2500 mPa·s at an ambient temperature of 25°C, and has a viscosity of 1.13 to 1.17 g / cm³. 3 Especially 1.15g / cm 3 The specific weight. The second component (the hardener) has a viscosity of 200 to 200 mPa·s and 300 mPa·s at an ambient temperature of 25°C, and a viscosity of 1.00 to 1.04 g / cm³. 3 Especially 1.02g / cm 3 The specific weight ratio is 5 parts resin to 1 part hardener. The volume ratio is 4.3 parts resin to 1 part hardener. The mixture has a viscosity of 1550 to 1750 mPa·s and 1650 mPa·s at an ambient temperature of 25°C, and a viscosity of 1.11 to 1.15 g / cm³. 3 Especially 1.13g / cm 3 The specific weight. The gelation time at 25°C is advantageously between 25 and 45 minutes, preferably 35 minutes.

[0027] The multi-component resin system is preferably highly reactive. The multi-component resin system is a 2K resin system.

[0028] Preferably, the second component has a viscosity of 40 to 300 mPa·s at an ambient temperature of 25°C.

[0029] In another advantageous embodiment of the invention, the resin is an epoxy resin, wherein the curing agent is an amine-based curing agent.

[0030] Amine-based curing agents offer the advantage of curing at room temperature, also known as cold curing. Epoxy resins are advantageous due to their excellent mechanical properties and minimal volume change during curing. Advantageously, epoxy resins contain no solvents and have VOCs <1% (volatile organic compounds, or VOCs for short), meaning that less than 1% by weight of the entire material evaporates during curing.

[0031] In another advantageous embodiment, the body rotates about an axis when it is immersed in, sprayed with or jetted with a multi-component resin system.

[0032] The main body is advantageously located on the rolling station.

[0033] According to the present invention, the first component and the second component are transported separately from each other, wherein the first component and the second component are immediately mixed into a multi-component resin system before immersion, spraying or spraying.

[0034] Immediately means preferably within 10 minutes.

[0035] The rotation of the main body prevents the resin system, especially resin dripping. The resin is drawn into the tank due to capillary forces and gels there within minutes. No dripping should be achieved after a maximum of 20 minutes. The main body can then be removed from the rotating station and processing can continue without prolonged hardening and / or cooling.

[0036] In another advantageous embodiment of the invention, the multi-component resin system has a viscosity of 300 mPa·s at 25°C.

[0037] This viscosity description is for the initial viscosity at 25°C. The actual viscosity is lower because the bulk has been heated to 30 to 80°C, particularly 30 to 60°C.

[0038] When mixing the first and second components, only a small viscosity difference is advantageous. A dynamic mixing tube allows for a larger viscosity difference than a static mixing tube.

[0039] In another advantageous embodiment of the invention, the multi-component resin system has a viscosity of 15,000 mPa·s after being injected onto the substrate, within a time period of 20 to 30 minutes.

[0040] According to the present invention, the multi-component resin system is formed into a jet with a dosage between 0.2 ml / s and 2 ml / s for spraying.

[0041] The dosage is advantageous because it allows for optimal delivery of the resin system. Furthermore, the dosage is advantageous because it allows for optimal drawing of the resin system into the winding via capillary force.

[0042] In another advantageous embodiment of the invention, at an ambient temperature of 15 to 25°C, especially 20 to 23°C, the multi-component resin system hardens by at least 95%, preferably at least 97%, after less than 100 hours, preferably less than 72 hours.

[0043] Multi-component resin systems are preferably cured without active heat input.

[0044] At room temperature, preferably after 24 hours, the multi-component resin system has cured by at least 97%.

[0045] The advantage of this invention is that further processing, which can only be performed at room temperature due to the coefficient of thermal expansion (e.g., installing bearing housings), can be carried out rapidly after impregnation. Active cooling is not required. Furthermore, delays caused by the cooling time of bearing surfaces used at room temperature are not necessary. Therefore, cost-effective and time-efficient production is possible.

[0046] Furthermore, the high energy consumption mentioned at the beginning, which involves heating the windings with currents exceeding 500A, is eliminated. Additionally, the production facility requires very expensive power electronic devices to control this current. This is also eliminated by the present invention.

[0047] The present invention also offers the advantage that a surface must not be provided in the production workshop, on which the body impregnated typically cools and hardens over several days or even weeks. This has a positive economic impact.

[0048] Another advantage of the present invention is that it is not necessary to pre-leave the resin in the resin basin, where there is always a risk of undesirable gelation.

[0049] 3K resin systems can also be considered for impregnation, reinforcement, or electrical insulation. Additives for preferred time-delayed thixotropic reactions can accelerate viscosity increases during gelation. This leads to improved production efficiency, especially in terms of cycle time. Attached Figure Description

[0050] The present invention will now be described and explained in more detail with reference to the embodiments shown in the accompanying drawings. The drawings show:

[0051] Figure 1 The impregnation method is shown.

[0052] Figure 2 Exemplary facilities for performing the impregnation method are shown, and

[0053] Figure 3 The rotating motor is shown during the impregnation process. Detailed Implementation

[0054] Figure 1 The impregnation method is shown.

[0055] In the first method step, a first component and a second component are provided. Figure 2 (Referring to reference numerals K1 and K2 in the accompanying drawings). The first component is preferably a resin, and the second component is preferably a hardener.

[0056] These two components are delivered separately in method step S2.

[0057] In method step S3, the two components are mixed to form a multi-component resin system. Figure 2 10), in this case, is a two-component resin system, and is preferably applied to the bulk immediately after mixing (in Figure 2 7) or introduced into the main body.

[0058] It is also possible to use more than two components.

[0059] In method step S4, the multi-component resin system is distributed in the cavity of the body by the rotation of the body. For example, when the body is a stator, the multi-component resin system is distributed in a tank.

[0060] Figure 2 An exemplary facility for performing the impregnation method is shown.

[0061] The first component K1 and the second component K2 are mixed in the mixing tube 3 at an exemplary mixing ratio of 100:20 to form a multi-component resin system 10, and are output as a jet 6 through the nozzle 5 to the main body 7. The main body rotates about axis A in the rotation direction R.

[0062] Figure 3 The rotating motor 12 is shown during the impregnation process. The stator 70 and rotor 71 are shown in the figure. The multi-component resin system 10 in the figure is injected onto the stator 70 through the nozzle 5, and the stator 70 rotates about axis A in the direction of rotation R.

[0063] During further production steps, the rotor and / or stator are typically exposed to increased temperatures. For example, this is followed by a winding temperature of approximately 80°C when the hot aluminum housing shrinks at 200°C, and a short-circuit test as a final test utilizing optional heating of the windings. The resin system is cured to almost 100%, which is ensured prior to completion, provided it is chemically feasible.

[0064] The resin system cures within a few days without subsequent heat treatment. Production flow remains undisturbed because it becomes a drip-free product within minutes, with little or no surface tack.

[0065] Impregnation offers numerous advantages, including significantly reduced energy costs and shorter cycle times depending on the material and production flow. By eliminating heat treatment, facility size and required surface area can be halved.

Claims

1. A method for impregnating, reinforcing, or electrically insulating a body (7) carrying a single or multiple layer windings, wherein, The main body supporting the winding is sprayed with a multi-component resin system. The main body (7) carrying the winding is sprayed with the multi-component resin system at an ambient temperature of 15°C to 25°C. The multi-component resin system (10) has at least two components, wherein the first component (K1) is a resin, and the second component (K2) is a curing agent. The first component (K1) and the second component (K2) are transported separately from each other, and the first component and the second component are mixed before spraying to form the multi-component resin system (10). Its features are, The first component has a viscosity of 2400 mPa∙s to 2600 mPa∙s at an ambient temperature of 25°C and a viscosity of 1.13 g / cm³. 3 Up to 1.17 g / cm 3 The proportion of Furthermore, the second component has a viscosity of 200 mPa∙s to 300 mPa∙s at an ambient temperature of 25°C, and a viscosity of 1.00 g / cm³. 3 Up to 1.04 g / cm 3 The proportion of The mixing ratio by weight is 5 parts resin to 1 part hardener, and the mixing ratio by volume is 4.3 parts resin to 1 part hardener. The mixture formed by mixing the first component (K1) and the second component (K2) has a viscosity of 1550 mPa∙s to 1750 mPa∙s at an ambient temperature of 25°C and a viscosity of 1.11 g / cm³. 3 Up to 1.15 g / cm 3 The proportion of The multi-component resin system (10) is formed into a jet (6) with a dose between 0.2 ml / s and 2 ml / s for spraying.

2. The method according to claim 1, wherein, The method is used for motor (12).

3. The method according to claim 1, wherein, The body (7) carrying the winding is sprayed with the multi-component resin system at an ambient temperature of 20°C to 23°C.

4. The method according to claim 1, wherein, The body (7) carrying the winding is preheated to a temperature of 30°C to 80°C.

5. The method according to claim 4, wherein, The main body (7) carrying the winding is preheated in an inductive manner.

6. The method according to any one of claims 1-5, wherein, The resin is an epoxy resin, wherein the curing agent is an amine-based curing agent.

7. The method according to any one of claims 1-5, wherein, When the body is sprayed with the multi-component resin system, the body (7) rotates about axis (A).

8. The method according to any one of claims 1-5, wherein, After being sprayed onto the main body (7), the multi-component resin system (10) has a viscosity of 15000 mPa∙s after a period of 20 to 30 minutes.

9. The method according to any one of claims 1-5, wherein, At an ambient temperature of 15°C to 25°C, the multi-component resin system (10) cured at least 95% in less than 100 hours.

10. The method according to claim 9, wherein, At an ambient temperature of 20°C to 23°C, the multi-component resin system (10) cured by at least 97% in less than 72 hours.

11. An electric motor (12), wherein, The motor is impregnated, reinforced, or electrically insulated according to any one of the preceding claims.

12. The motor according to claim 11, wherein, The motor is an electric motor, a generator, or a transformer.

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