Device and method for cleaning a rotor of an electrical machine

Abstract

Device (1) for cleaning a rotor (2) of an electrical machine with - a holding unit for holding the rotor (2), which has a rotation axis and a radial inner side and a radial outer side, - a cleaning arrangement (3) comprising a number of spray heads (3.1, 3.2) for applying a cleaning medium (M) under high pressure to the rotor (2), and - a drive unit for a relative rotation of the rotor (2) and the cleaning arrangement (3) to each other, namely about the rotation axis, - wherein at least one outer first spray head (3.1) is provided for applying the cleaning medium (M) to the radial outer side of the rotor (2) and - wherein at least one inner second spray head (3.2) is provided for applying the cleaning medium (M) to the radial inside of the rotor (2).

Description

[0001] The invention relates to a device for cleaning a rotor of an electrical machine with a holding unit for holding the rotor, a cleaning arrangement and a drive unit for a relative rotation of the rotor and the cleaning arrangement to each other.

[0002] The invention further relates to a method for cleaning a rotor of an electrical machine using such a device.

[0003] During operation of an electrical machine, metallic contaminants caused by abrasion, particularly soft magnetic particles, can build up on the rotor of the electrical machine, which can impair its operation. Particularly during maintenance and repair of an electrical machine, it is important to ensure that soft magnetic particles are not introduced into the machine. Such a rotor may also already be contaminated before the electrical machine is initially installed. Various devices and methods are known from the prior art for cleaning such a rotor of an electrical machine in an uninstalled state.

[0004] Such a device for cleaning a permanently excited rotor of an electrical machine is described in DE 10 2011 118 975 A1. The rotor, contaminated with adhering soft magnetic materials and removed from the electrical machine, is rotatable by means of a drive device. A centrifugal force acts on the soft magnetic materials. The rotor is surrounded, at least in sections in the axial direction and circumferentially, by a magnetic field-generating device whose magnetic field weakens or cancels out a magnetic field generated by the permanent magnets of the rotor and attracts the soft magnetic materials thus detached from the rotor.Furthermore, a method for cleaning a permanent magnet rotor of an electrical machine is described, in which the rotor is rotated in such a way that a centrifugal force acts on soft magnetic materials adhering to the rotor, which is greater than the attractive force between the permanent magnets of the rotor and the adhering soft magnetic materials. The soft magnetic materials thus removed are attracted by a magnetic field surrounding the rotor.

[0005] Further cleaning devices are known from the documents DE 94 16 129 U1, DE 43 42 593 A1 and WO 2010 / 062 894 A1.

[0006] It is also known from the state of the art to clean rotors of electrical machines manually using suitable cloths.

[0007] The invention is based on the object of providing a device and an improved method for cleaning a rotor of an electrical machine that are improved compared to the prior art.

[0008] With regard to the device, the object is achieved according to the invention by the features specified in claim 1 and with regard to the method by the features specified in claim 8.

[0009] Advantageous embodiments of the invention are the subject of the subclaims.

[0010] The device for cleaning a rotor of an electrical machine comprises a holding unit for holding the rotor, a cleaning arrangement and a drive unit for a relative rotation of the rotor and the cleaning arrangement to each other.

[0011] According to the invention, the cleaning arrangement comprises a number of spray heads for applying a cleaning medium under high pressure to the rotor.

[0012] In this context, high pressure specifically means that the cleaning medium impinges on the surface of the rotor at a pressure in the range of 10 bar to 150 bar. The pressure is adjusted, in particular, depending on the rotor's magnetic force. An additional influencing factor is the volume flow of the cleaning medium. To achieve a good cleaning result, both the pressure and the volume flow are crucial. Both the volume flow and the pressure are adjustable, and both can be selected independently of each other for different rotors.

[0013] It is also possible to adjust or change the pressure and flow rate during the cleaning process, allowing cleaning to be carried out particularly efficiently and cost-effectively. For example, coarse contamination can be removed at the beginning of the cleaning process using a lower high pressure, and then the stuck-on particles can be flushed away using a higher pressure. To ensure complete cleaning, however, a cleaning agent must also hit the rotor with a sufficient flow rate at high pressure.

[0014] The device advantageously enables effective, complete, and low-cost cleaning of the rotor, allowing both the reuse of used rotors and the installation of unused rotors in electrical machines in a clean condition. The device is characterized by a particularly simple and cost-effective design.

[0015] Embodiments of the invention are explained in more detail below with reference to drawings.

[0016] Showing: Fig. 1 schematically shows a sectional view of a device according to the invention and a permanently excited rotor during cleaning, Fig. 2 schematically shows a plan view of a front side of the rotor according to Fig. 1 during cleaning, Fig. 3 schematically shows a first perspective view of a section of the device and the rotor according to Fig. 1, and Fig. 4 schematically shows a second perspective view of a section of the device and the rotor according to Fig. 1.

[0017] Corresponding parts are provided with the same reference numerals in all figures.

[0018] In the Fig. 1 to 4, a possible embodiment of a device 1 according to the invention for cleaning a rotor 2 of an electrical machine is shown in various views, wherein the device 1 can be part of a system (not shown), in which the device 1 can be loaded with the respective rotor 2 to be cleaned and the rotor 2 can be removed fully automatically.

[0019] The rotor 2 is a permanently excited rotor 2 or a rotor 2 that is magnetized during operation of the electric machine, which can also be magnetized after operation of the electric machine due to hysteresis effects. In the illustrated embodiment, the rotor 2 is designed as a so-called internal rotor.

[0020] Due to this magnetization, magnetic particles generated during operation of the electrical machine due to wear or magnetic particles already present in the vicinity of the rotor 2 before installation of the rotor 2 in the electrical machine are deposited on the rotor 2, which can lead to an impairment of the operation of the electrical machine.

[0021] To remove these magnetic particles and any other deposits or contaminants adhering to the rotor 2, the rotor 2 is cleaned in the removed state by means of the device 1.

[0022] For this purpose, the rotor 2 is attached to a holding unit (not shown in detail) of the device 1 and positioned by means of this holding unit relative to a cleaning arrangement 3. The positioning takes place in such a way that the rotor 2 is aligned relative to the cleaning arrangement 3. Alternatively or additionally, the cleaning arrangement 3 is positioned relative to the rotor 2. To insert the rotor 2 into the device 1, the device comprises an opening mechanism (not shown in detail) and / or the insertion takes place by opening or folding away the holding unit.

[0023] The holding unit is designed such that the rotor 2 is rotated relative to the cleaning arrangement 3 in a rotation R during cleaning. For this purpose, the holding unit comprises a drive unit (not shown) or is coupled to it.

[0024] In the illustrated embodiment, the cleaning arrangement 3 comprises two spray heads 3.1, 3.2 for applying a liquid cleaning medium M under high pressure to the rotor 2 during cleaning.

[0025] In one possible embodiment, the cleaning medium M comprises additives to enhance cleaning and maintenance performance. For example, grease-dissolving substances or so-called degreasers are added to the cleaning medium M, by means of which the rotor 2 can also be freed of greasy dirt or deposits. Alternatively or additionally, corrosion-protective substances and / or sealants can be added to the cleaning medium M, which seal a surface of the rotor 2 and protect it from re-contamination.

[0026] In a possible embodiment, it is also provided that the cleaning medium M and the additives are applied to the rotor 2 in separate steps.

[0027] High pressure, in this case, is understood in particular to mean that the cleaning medium M impinges on a surface of the rotor 2 at a pressure in the range of 10 bar to 150 bar, for example 30 bar. The pressure is adjusted in particular as a function of a magnetic force of the rotor 2, so that the magnetic particles and any other adhering deposits and / or contaminants are released. Energy consumption can also be minimized because only the pressure required to overcome the magnetic force is adjusted. The volume flow of the cleaning medium M serves as a further control variable. This depends on the number and shape of the nozzles. Furthermore, a larger volume flow is required at lower pressures and a smaller volume flow at higher pressures.

[0028] An outer first spray head 3.1 is arranged such that it generates a conical jet S1 of the cleaning medium M with a small opening angle essentially in the radial direction of the rotor 2 and applies this jet S1 to an outer side of the rotor 2. In order to clean the entire outer side of the rotor 2, the spray head 3.1 is moved in the axial directions -X, +X during the rotation R of the rotor 2 about the axis of rotation parallel to this axis of rotation. The movement of the spray head 3.1 and the rotation of the rotor can occur together and thus overlap, or the movements occur one after the other, so that either during a rotation of the rotor 2 the spray head 3.1 is held in one position so that the outer surface is cleaned in a ring shape, and then after at least one complete rotation the spray head 3.1 is moved axially to the next position.Alternatively, the rotor 2 is held in its position and the spray head 3.1 is moved axially, whereby after completely sweeping over the axial length of the rotor 2, the latter is rotated by a defined angular section into the next rotational position, so that the remaining areas of the outer surface are subsequently cleaned.

[0029] An inner second spray head 3.2 is arranged in such a way that it generates a fan-shaped jet S2 of the cleaning medium M with a large opening angle in the radial and axial directions and applies this jet S2 to an inner side of the rotor 2. The jet S2 is designed in such a way that, by means of it, the entire inner side of the rotor 2 is exposed to the cleaning medium M during its rotation R without any relative axial movement of the rotor 2 and the second spray head 3.2 to one another. The second spray head 3.2 is arranged in the region of the axis of rotation of the rotor 2 in the device 1 or radially spaced from it. In an embodiment not shown in detail, a movement of the second spray head 3.2 in the axial directions -X, +X is also provided.Thus, by means of the device 1, rotors 2 with different lengths can be cleaned and / or a full-surface cleaning of different rotors 2 can be realized with different opening angles of the jet S2.

[0030] This arrangement and design of the spray heads 3.1, 3.2 is particularly advantageous for the internally rotor 2. The strongest magnetic forces act on the outer surfaces of this rotor 2, so that the adhesion of the magnetic particles is greatest in these areas. Due to the focused jet S1, the acting magnetic forces can be overcome, ensuring optimal cleaning of the rotor 2.

[0031] When the rotor 2 is designed as a so-called external rotor, the greatest magnetic forces act on the inside of the rotor 2. In order to achieve optimal cleaning even with this design of the rotor 2, the spray heads 3.1, 3.2 are designed to be interchangeable and / or the shape and opening angles of the jets S1, S2 are variably adjustable. In one possible embodiment, the spray heads 3.1, 3.2 are fastened in the device 1 in such a way that they can be interchanged without disassembly. This means that the spray heads 3.1, 3.2 are arranged, for example, in such a way that they can be rotated, pivoted, tilted and / or folded that one spray head 3.1, 3.2 can be easily transferred into the position of the other spray head 3.2, 3.1.

[0032] In one possible embodiment of the device 1, at least one of the spray heads 3.1, 3.2 is arranged to be movable in the radial direction. This simplifies the insertion of the rotor 2 into the device 1, and also allows rotors 2 with different diameters to be cleaned by the device 1. This also allows for adjustment of the focusing and guidance of the jets S1, S2, thus enabling cleaning to be adapted to the magnetic force and the shape and configuration of the rotor 2, whether as an inner rotor or an outer rotor.

[0033] In a further possible embodiment of the device 1, it comprises, in a manner not shown in detail, a sensor unit for detecting the rotor 2 or at least the rotor dimensions, so that corresponding settings, positions, and movement lengths of the spray heads 3.1, 3.2 are automatically detected and adjusted. Alternatively or additionally, these values ​​and parameters can also be manually specified and / or selected. For example, each rotor 2 is provided with a corresponding identifier, for example, an optoelectronically readable inscription, by which it can be identified by the device.

[0034] A possible further development of the device 1 (not shown) provides that the device 1 comprises a drying arrangement for drying the rotor 2 after its cleaning. The drying arrangement comprises, for example, fans and / or heating devices, wherein drying parameters, for example a temperature, are individually specified manually or automatically in order to avoid thermal overloads of the rotor 2 and resulting damage to the rotor. List of reference symbols 1 device 2 Rotor 3 Cleaning arrangement 3.1 Spray head 3.2 Spray head M cleaning medium R Rotation S1 beam S2 beam -X direction +X direction

Claims

[1] Device (1) for cleaning a rotor (2) of an electrical machine with - a holding unit for holding the rotor (2), which has a rotation axis and a radial inner side and a radial outer side, - a cleaning arrangement (3) comprising a number of spray heads (3.1, 3.2) for applying a cleaning medium (M) under high pressure to the rotor (2), and - a drive unit for a relative rotation of the rotor (2) and the cleaning arrangement (3) to each other, namely about the rotation axis, - wherein at least one outer first spray head (3.1) is provided for applying the cleaning medium (M) to the radial outer side of the rotor (2) and - wherein at least one inner second spray head (3.2) is provided for applying the cleaning medium (M) to the radial inside of the rotor (2). [2] Device (1) according to claim 1, wherein the at least one first spray head (3.1) is designed at least to generate a conical jet (S1) of the cleaning medium (M) with a small opening angle onto the outside of the rotor (2). [3] Device (1) according to claim 1 or 2, wherein the at least one second spray head (3.2) is designed at least to generate a fan-shaped jet (S2) of the cleaning medium (M), a flat parallel jet (S2) of the cleaning medium (M) or a conical jet (S2) of the cleaning medium (M) with a large opening angle onto the inside of the rotor (2). [4] Device (1) according to one of the preceding claims, wherein at least one spray head (3.1, 3.2) of the number of spray heads (3.1, 3.2) is arranged to be movable parallel to a rotation axis of the rotor (2). [5] Device (1) according to one of the preceding claims, wherein a distance of at least one spray head (3.1, 3.2) of the number of spray heads (3.1, 3.2) from the rotor (2) can be variably predetermined. [6] Device (1) according to one of the preceding claims, wherein the cleaning medium (M) comprises a liquid. [7] Device (1) according to one of the preceding claims, wherein a drying arrangement is provided for drying the rotor (2). [8] Method for cleaning a rotor (2) of an electrical machine using a device (1) according to one of the preceding claims, wherein - the rotor (2) is held by the holding unit, - by means of the drive unit a relative rotation of the rotor (2) and the cleaning arrangement (3) is carried out to each other and - by means of the number of spray heads (3.1, 3.2) of the cleaning arrangement (3), the rotor (2) is subjected to the cleaning medium (M) under high pressure. [9] Method according to claim 8, wherein the high pressure is adjusted as a function of a magnetic force of the rotor (2). [10] Method according to claim 8 or 9, wherein the cleaning medium (M) comprises grease-dissolving substances and / or corrosion-protecting substances and / or sealants.

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