DE102020114459A1 - Procedure for testing a rotor - Google Patents

Abstract

The invention relates to a method for testing a rotor (16) of an electrical machine during manufacture of the rotor (16), the rotor (16) having poles, the rotor (16) being balanced in one manufacturing step, during which a radial expansion of the poles of the rotor (16) is measured.

Description

The invention relates to a method for testing a rotor of an electrical machine and a testing system for testing a rotor of an electrical machine.

After an electrical machine has been manufactured, it can be tested in a final inspection before it is made available for use.

The pamphlet CN 107979201 A shows a motor with windings.

A method for encapsulating a motor is from the document US 6136250 A known.

An electrical machine is in the document US 20150048713 A1 described.

Against this background, it was a task to efficiently check the functionality of an electrical machine.

This object is achieved by a method and a test system with the features of the independent patent claims. Embodiments of the method and the test system emerge from the dependent claims and the description.

The method according to the invention is provided for checking, examining and / or testing a rotor of an electrical machine during manufacture of the rotor, the rotor having several, for example 2 * n poles or n pole pairs. The rotor is set in rotation or rotated and balanced in one production step. In the method, during or synchronously with the balancing of the rotor, a radial expansion or expansion of a respective pole of the rotor, generally all poles of the rotor, is measured, recorded and / or ascertained.

Here, in a possible embodiment, a local and / or inhomogeneous expansion of a circumference or an outer wall of a respective pole is measured, recorded and / or ascertained as a radial expansion, for example. In this case, wires for windings of the poles are encapsulated and / or cast in grooves between two pole teeth with a potting compound or potting material, an expansion or expansion of the potting material or potting with the wires cast or enclosed therein being measured by sensors during balancing and / or is detected. Any delamination or detachment between a laminated core of the rotor and the potting can be measured.

The method is carried out for an electrical machine which is designed or can be referred to as a separately excited synchronous machine. The electrical machine to be tested or examined with the method, e.g. separately excited synchronous machine, can be used to operate a device, e.g. .

The method is used, for example, to measure a path, a route or a distance which specifies, describes and / or defines the radial expansion of the poles, in the event that the route for a respective pole is at most as large as A threshold value provided for this is for a maximum permissible expansion, the respective pole of the rotor is OK, and in the event that the distance is greater than the threshold value provided for the maximum permissible expansion, the respective pole of the rotor is not OK is. The rotor is OK or intact if all poles are OK. On the other hand, the rotor is not OK if at least one pole is not OK.

The rotor is set in rotation or rotated and balanced with a rotor balancing device or a balancing machine, the rotor being attached to the rotor balancing device or balancing machine, rotated and balanced, with the expansion being measured by sensors with a measuring system . The test or examination of the rotor combined with the balancing of the rotor can be carried out at a normal ambient or room temperature of approx. 20 ° C. However, it is also possible to heat or heat the rotor during this, depending on the definition.

The rotor is balanced and checked after its poles have been or have previously been cast or potted in a manufacturing step. When the rotor is manufactured, wires for coils or windings of the poles are arranged in grooves between pole teeth, which are formed from a laminated core, and are potted or cast in the grooves with a potting material or a potting compound. The electrical machine is then balanced and the expansion measured synchronously, with the condition of the poles being checked.

The test system according to the invention is designed for testing a rotor of an electrical machine during manufacture of the rotor, the rotor having poles, the testing system having a rotor balancing device or a balancing device and a measuring system. The rotor balancing device is designed to hold the rotor in to set in rotation or to rotate and to balance a step of the production. The measuring system, which has at least one measuring device or at least one sensor, is designed to measure or detect a radial expansion or expansion of a respective pole of the rotor, usually all poles, of the rotor by means of sensors.

The measuring system can be designed as an optical measuring system or as a capacitive measuring system for the path to be measured or for the distance to be measured. The optical measuring system can have at least one camera, for example a high-speed camera, or a laser displacement measuring system. The capacitive measuring system can have at least one capacitive displacement sensor. It is also possible that the measuring system is designed as an eddy current measuring system with at least one eddy current sensor or has at least one ohmic displacement transducer.

With the method or a corresponding method, a production-integrated quality assurance of the, for example, epoxy resin-based full encapsulation in the rotor, for example in the slots between pole teeth, of the separately excited synchronous machine is carried out in the manufacturing process of the separately excited synchronous machine. The method can be carried out with an embodiment of the test system presented. In addition, the test system is designed to carry out an embodiment of the method. The method can be carried out for a rotor of an electrical machine which is provided or designed to drive a vehicle.

When the rotor of the separately excited synchronous machine (FSM) is manufactured, after the windings have been cast, the assembly provided with the rotor balancing device is thrown and balanced anyway. In this already existing production step, the centrifugal force-induced radial expansion of the poles can be measured when the method is carried out. A widening of an outer wall of a respective pole can be determined, which can be angle-dependent and thus inhomogeneous.

With the method, an additional quality check and / or quality assurance as well as time and cost savings can be achieved, since the quality assurance can be easily integrated into the manufacturing process when the rotor is checked during balancing. The widening can, for example, be determined and / or measured by sensors using an optical measuring method in which the at least one optical displacement transducer is used as a measuring system, or as a capacitive measuring method in which the at least one capacitive displacement transducer is used. The definition of a maximum permissible expansion above the threshold value provided for this enables automated identification of rejects and thus of a possibly defective rotor. Since every rotor has to be balanced or balanced during production and is thus spun, only the measuring system is to be attached or arranged on the rotor balancing device. An additional manufacturing step is therefore not necessary.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination, but also in other combinations or on their own, without departing from the scope of the present invention.

• 1 zeigt in schematischer Darstellung ein Detail eines ersten Beispiels eines Rotors für eine elektrische Maschine, für die eine Ausführungsform des Verfahrens durchführbar ist.
• 2 zeigt ein Diagramm mit Werten einer Aufweitung, die für zwei weitere Beispiele von Rotoren für elektrische Maschinen bei Durchführung einer ersten Ausführungsform des erfindungsgemäßen Verfahrens gemessen werden.
• 3 zeigt in schematischer Darstellung eine Ausführungsform des erfindungsgemäßen Prüfsystems, ein viertes Beispiel eines Rotors einer elektrischen Maschine und Diagramme für Werte einer Aufweitung, die bei Durchführung einer zweiten Ausführungsform des erfindungsgemäßen Verfahrens an einer ersten axialen Messbezugsebene des zweiten Beispiels des Rotors gemessen werden.
• 4 zeigt in schematischer Darstellung die Ausführungsform des erfindungsgemäßen Prüfsystems aus 3, das Detail des vierten Beispiels des Rotors der elektrischen Maschine und Diagramme mit Werten einer Aufweitung, die bei Durchführung der zweiten Ausführungsform des erfindungsgemäßen Verfahrens an einer zweiten axialen Messbezugsebene des Rotors gemessen werden.
• 5 zeigt weitere Diagramme mit weiteren Werten einer Aufweitung, die bei Durchführung der zweiten Ausführungsform des erfindungsgemäßen Verfahrens an dem vierten Beispiel des Rotors für die elektrische Maschine gemessen werden.

The invention is shown schematically on the basis of embodiments in the drawings and is described schematically and in detail with reference to the drawings.

• 1 shows a schematic representation of a detail of a first example of a rotor for an electrical machine, for which an embodiment of the method can be carried out.
• 2 shows a diagram with values of a widening which are measured for two further examples of rotors for electrical machines when carrying out a first embodiment of the method according to the invention.
• 3 shows a schematic representation of an embodiment of the test system according to the invention, a fourth example of a rotor of an electrical machine and diagrams for values of an expansion that are measured on a first axial measurement reference plane of the second example of the rotor when a second embodiment of the method according to the invention is carried out.
• 4th shows the embodiment of the test system according to the invention in a schematic representation 3 , the detail of the fourth example of the rotor of the electrical machine and diagrams with values of an expansion that are measured on a second axial measurement reference plane of the rotor when the second embodiment of the method according to the invention is carried out.
• 5 shows further diagrams with further values of an expansion, which are measured when the second embodiment of the method according to the invention is carried out on the fourth example of the rotor for the electrical machine.

The figures are described coherently and comprehensively, the same components are assigned the same reference symbols.

In 1 a detail of a rotor of the first example of the electrical machine, here a separately excited synchronous machine, is shown schematically, the rotor having a plurality of pole teeth 1a , 1b has, which are formed from laminated cores, of which two directly adjacent pole teeth here 1a , 1b are shown in sections. Between the two pole teeth 1a , 1b there is a groove in which wires 2a , 2 B , 2c , 2d are arranged for windings of the rotor, sections of which are shown here. There are two first wires 2a , 2 B around the first pole tooth 1a and two more wires 2c , 2d around the second pole tooth 1b wrapped. The wires 2a , 2 B , 2c , 2d are here in the groove through a potting process with potting material 4th potted or poured into it.

It is possible that due to variations in the potting process of the separately excited synchronous machines with full potting, for example, there are variations in the viscosity of the starting material, for example epoxy resin, for the potting material 4th , to variations in the temperature during the potting process, to variations in the composition of the potting material 4th and / or variations in filler sedimentation can occur. Variations of this kind can lead to air inclusions that affect the service life, for example strength-critical, and to imperfect adhesion between the potting material 4th and a slot insulation. A reduction in the potting strength can lead to unwanted cracking in the potting material 4th conditional under operational load. Through gaps between the wires 2a , 2 B , 2c , 2d electrical field increases arise (circle 6th ). Partial discharges result from these field increases. In the long run, these lead to failure of an insulation of the slot or a slot insulation.

The diagram out 2 shows results that have been determined in the first embodiment of the method according to the invention and includes a linear abscissa 8th , along which values for angles are plotted in degrees, and an ordinate 10 , along which values for a relative expansion, for example a relative expansion, and thus for a distance or a path in µm are plotted. The first embodiment of the method was carried out for a second example of a rotor of an electrical machine and a third example of a rotor of an electrical machine, each rotor having three pole pairs and thus six poles. The expansion of their poles was measured for both rotors, while one rotor was or has been balanced during its manufacture. The solid curves show in the diagram 12th the angle-dependent or local expansion of the poles of the second rotor and the dashed curves 14th the angle-dependent or local expansion of the poles of the third rotor.

The measurement of the widening of the poles of the respective rotor or a result of this measurement can act as an indicator for the quality of the potting and, if necessary, be used as a reject criterion. In the case of cracks or cavities in the potting or delamination between the potting and a laminated core with pole teeth of the rotor, the radial expansion of the laminated core in the area of the poles is greater, which is shown in the diagram by the dashed curves 14th is indicated, as in the case of an intact potting within a groove between two directly adjacent pole teeth, which is indicated here by black continuous or solid curves 12th is indicated. It is provided here that the widening or expansion of the poles of the intact rotor (curves 12th ) is lower than a permissible threshold value provided for this purpose, whereas the expansion for the defective or faulty rotor (curves 14th ) is greater than this threshold.

The following 3a and 4a each show the fourth example of the rotor 16 , here a centrifugal rotor (SR), for an electrical machine, which is designed or referred to here as a separately excited synchronous machine. This rotor 16 has several, here six pole teeth 18a , 18b on, which are formed from laminated cores, with two immediately adjacent pole teeth 18a , 18b each has a groove in which wires for windings or for coils are arranged, which are used during manufacture of the rotor 16 be cast in a potting compound, the rotor 16 here has three pole pairs or six poles.

Also show both 3a and 4a a rotor balancing device 60 or a balancing device and an optical measuring system here 62 the embodiment of the test system according to the invention, which is designed to carry out the second embodiment of the method according to the invention. In 3a a first measurement reference plane 20th at one axial end of the rotor 16 indicated in the embodiment of the method with the measuring system 62 is sensed. In 4a is a second measurement reference plane 22nd in an axial center of the rotor 16 indicated in the embodiment of the method with the measuring system 62 is sensed.

To carry out the embodiment of the method in the context of manufacturing the rotor 16 this is done in one step after the wires have been or have been arranged in the grooves and have been or have been encapsulated in the grooves with the potting material for balancing on the rotor balancing device 60 arranged and with this rotated or set in rotation, at the same time, that is, while the rotor 16 with the rotor balancing device 60 is balanced with the measuring system 62 in addition, the radial expansion or expansion of the poles in the grooves between the pole teeth 18a , 18b is determined and / or measured.

For this, reference is also made to the diagrams, whereby the rotor 16 the end 3a if a measurement of the temperature-induced or temperature-dependent radial expansion of the poles in the first measurement reference plane 20th from the measuring system 62 detected by sensors and thus ascertained, for example measured, the diagrams from the 3b , 3c and 3d associated with the results of this measurement. Furthermore are the rotor 16 the end 4a if a measurement of the radial expansion of the poles in the second measurement reference plane 22nd from the measuring system 62 detected by sensors and thus ascertained, for example measured, the diagrams from the 4b , 4c and 4d associated with the results of this measurement.

In addition, the second embodiment of the method with the test system is also used for the fourth example of the rotor 16 performed again. This is off in the diagram 5a a result of the measurement of the radial centrifugal force-dependent or centrifugal force-induced expansion of the poles in the first measurement reference plane 20th and in the diagram 5b a result of the measurement of the radial centrifugal force-dependent or centrifugal force-induced expansion of the poles in the second measurement reference plane 22nd shown.

The diagrams in the 3b and 4b each have a linear abscissa 24 , along which the time in hours (h) is plotted, and an ordinate 26th along which a mean relative expansion of the poles in micrometers (µm) is plotted. The diagrams from the 3c , 4c exhibit a linear abscissa 30th along which an angle of the rotor 16 or a rotor angle is plotted in degrees, and an ordinate 32 on, along which the relative radial expansion or expansion of the poles of the rotor 16 is plotted in micrometers (µm) if the rotor is 16 during balancing by the rotor balancing device 60 is rotated.

The diagrams 3d, 4d, 5a and 5b are shown in relation to polar coordinates and each have a circular abscissa 36 , along the angle of the rotor 16 are plotted in degrees, and an ordinate 38 on, along the one widening of the poles of the rotor 16 is plotted in micrometers (µm) if the rotor is 16 during balancing for checking or with the rotor balancing device 60 is rotated, the expansion of the measuring system 62 is measured.

A curve 28 in the diagram 3b shows for the rotor 16 the time-dependent, relative mean or correspondingly average, temperature-induced expansion of all six poles in the first measurement reference plane 20th when balancing the rotor 16 with the rotor balancing device 60 when starting a test or a test at a temperature of approx. 180 ° C for subsequent tests or follow-up tests.

A curve 46 in the diagram 4b shows for the rotor 16 the time-dependent, relative mean or correspondingly average, temperature-induced expansion of all six poles in the second measurement reference plane 22nd when balancing the rotor 16 with the rotor balancing device 60 when starting a test or a test at a temperature of approx. 180 ° C for subsequent tests or follow-up tests.

A comparison of the two curves 28 , 46 shows that the curve 28 for the first measurement reference plane 20th asymptotically approaches a higher value for the widening than is the case with the curve 46 for the second measurement reference plane 22nd is the case that asymptotically approaches a lower value. Accordingly, the poles are at the axial end of the rotor 16 stronger during balancing than in the axial center of the rotor 16 widened or expanded if this is heated to 180 ° C during balancing and synchronous testing of its expansion.

Such a difference for the two different measurement reference planes axially offset along an axis of the rotor 20th , 22nd for the relative expansion or widening which is individual for a respective pole, which results during balancing, is also shown in the diagrams of 3c , 3d , 4c , 4d , 5a and 5b .

Each one of a total of six curves 34a , 34b in the diagram 3c shows the temperature-induced relative expansion for one pole of the rotor 16 with respect to the linear abscissa 30th in the first measurement reference plane 20th . In the diagram 3d is indicated by a dashed circle 48 a first curve for the temperature-induced expansion of the poles given by the measuring system 62 in the first measurement reference plane 20th is measured when the rotor 16 from the rotor balancing device 60 is rotated at 3000 revolutions per minute during balancing. When the rotor 16 with or from the rotor balancing device 60 is rotated at 17000 revolutions per minute, results in the first measurement reference plane 20th for one pole of the total of six poles, an angle-dependent expansion or widening, which is represented here by a curve 40a , 40b is shown falling on the circular abscissa 36 is related and from the measuring system 62 is measured.

One of a total of six curves in each case 42a , 42b in the diagram 4c shows the relative expansion for one pole of the rotor 16 with respect to the linear abscissa 30th in the second measurement reference plane 22nd . In the diagram 4d is indicated by a dashed circle 49 a first curve for the temperature-induced expansion of the poles given by the measuring system 62 in the second measurement reference plane 22nd is measured when the rotor 16 from the rotor balancing device 60 is rotated at 3000 revolutions per minute during balancing. When the rotor 16 with or from the rotor balancing device 60 is rotated at 17,000 revolutions per minute, results for one pole of the total of six poles in the second measurement reference plane 22nd an angle-dependent expansion or widening, which is represented here by a curve 44a , 44b is shown falling on the circular abscissa 36 is related and from the measuring system 62 is measured.

In the diagram 5a is indicated by a dashed circle 70 a first curve for an expansion of the poles of the rotor induced or caused by centrifugal force or the centrifugal force-induced expansion 16 specified by the measuring system 62 in the first measurement reference plane 20th is measured at room temperature of, for example, 20 ° C if the rotor 16 from the rotor balancing device 60 is rotated at 3000 revolutions per minute during balancing. When the rotor 16 with or from the rotor balancing device 60 is rotated at 17000 revolutions per minute, results in the first measurement reference plane 20th for one pole of the total of six poles, a purely centrifugal force-induced, angle-dependent expansion or widening, which is represented here by a curve 50a , 50b is shown falling on the circular abscissa 36 is related and from the measuring system 62 is measured.

In the diagram 5b is indicated by a dashed circle 72 a first curve for the centrifugal force-induced expansion of the poles given by the measuring system 62 in the second measurement reference plane 22nd is measured when the rotor 16 from the rotor balancing device 60 is rotated at 3000 revolutions per minute during balancing. When the rotor 16 with or from the rotor balancing device 60 is rotated at 17,000 revolutions per minute, results for one pole of the total of six poles in the second measurement reference plane 22nd a centrifugal force-induced, angle-dependent expansion or widening, each represented here by a curve 52a , 52b is shown falling on the circular abscissa 36 is related and from the measuring system 62 is measured.

Here shows a comparison of the respective angle-dependent curves 40a , 40b in the diagram 3d , the angle-dependent curves 44a , 44b in the diagram 4d , the angle-dependent curves 50a , 50b in the diagram 5a and the angle-dependent curves 52a , 52b in the diagram 5b that the expansion or expansion in the first measurement reference plane 20th larger than in the second measurement reference plane 22nd is.

There are absolute values for the expansion here from a position of a respective measurement reference plane 20th , 22nd are dependent along the axis and are larger at the axial end than in the middle, the expansion or expansion in the embodiment could be at the axial end, here in the first measurement reference plane 20th be measured, since the higher values for the expansion are here by the measuring system 62 can possibly be recorded more easily than at the second measurement reference plane 22nd the case is. Accordingly, it would be conceivable to use the rotor 16 during balancing and simultaneous measurement of the expansion, in order to also achieve larger values that are determined by the measuring system 62 can be recorded more easily. If the measuring system 62 has a plurality of measuring devices or sensors which are designed to detect or measure the expansion, these could be along the axis of the rotor 16 be arranged offset, with an axial course of the expansion can be detected.

It is provided here that the values for the expansion or expansion for all poles of the rotor 16 are smaller or less than a respectively provided or defined maximum permissible threshold value, which is why in the method with the measuring system 62 it is determined or proven that the rotor shown here 16 is OK or intact. The threshold value can be temperature-dependent and / or dependent on an axial position of a respective measurement reference plane 20th , 22nd defined or provided.

Alternatively, if there is a deviation from the curves shown 40a , 40b , 44a , 44b , 50a , 50b , 52a , 52b for the expansion during balancing of the rotor 16 by the rotor balancing device 60 caused and with the measuring system 62 should be measured, strength-relevant or strength-critical casting defects of the poles of the rotor 16 be closed, which is the case when the curves 40a , 40b , 44a , 44b , 50a , 50b , 52a , 52b Should have values which should be greater or higher than the maximum permissible threshold values in each case.

List of reference symbols

1a, 1b

Pole tooth

2a, 2b, 2c, 2d

wire

4th

Potting material

6th

circle

8th

abscissa

10

ordinate

12, 14

Curve

16

rotor

18a, 18b

Pole tooth

20.22

Measurement reference plane

24

abscissa

26th

ordinate

28

Curve

30th

abscissa

32

ordinate

34a, 34b

Curve

36

abscissa

38

ordinate

40a, 40b

Curve

42a, 42b

Curve

44a, 44b

Curve

46

Curve

48, 49

circle

50a, 50b

Curve

52a, 52b

Curve

60

Rotor balancing device

62

Measuring system

70, 72

circle

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• CN 107979201 A [0003]
• US 6136250 A [0004]
• US 20150048713 A1 [0005]

Claims (8)

A method for testing a rotor (16) of an electrical machine during manufacture of the rotor (16), the rotor (16) having poles, the rotor (16) being balanced in a manufacturing step, during which the poles are radially expanded of the rotor (16) is measured. Procedure according to Claim 1 , which is carried out for a rotor (16) of an electrical machine, which is designed as a separately excited synchronous machine. Procedure according to Claim 1 or 2 , in which a distance is measured which indicates the radial expansion of the poles, with the respective pole of the rotor (16 ) is in order, and in the event that the distance is greater than the threshold value provided for this for the maximum permissible expansion, the respective pole of the rotor (16) is not in order. Method according to one of the preceding claims, in which the rotor (16) is set in rotation and balanced with a rotor balancing device (60). Method according to one of the preceding claims, in which the rotor (16) is balanced and checked after the poles have previously been cast in a manufacturing step. Method according to one of the preceding claims, which is carried out for a rotor (16) of an electrical machine which is provided for driving a vehicle. Test system for testing a rotor (16) of an electrical machine during manufacture of the rotor (16), the rotor (16) having poles, the testing system having a rotor balancing device (60) and a measuring system (62), the rotor balancing device (60 ) is designed to balance the rotor (16) in one manufacturing step, the measuring system (62) being designed to measure a radial expansion of the poles of the rotor (16) during this time. Test system according to Claim 7 , in which the measuring system (62) is designed as an optical measuring system (62) or as a capacitive measuring system (62).

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