WO2020098870A1

WO2020098870A1 - Electric machine with inherent rotor position sensor with integrated temperature sensor

Info

Publication number: WO2020098870A1
Application number: PCT/DE2019/100941
Authority: WO
Inventors: Andreas Bexel; Michael Marsetz
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2018-11-12
Filing date: 2019-11-04
Publication date: 2020-05-22
Also published as: DE102018128176A1

Abstract

The invention relates to an electric machine (1) for a drive of a motor vehicle, having a stator (2), a rotor (3) which can rotate relative to the stator (2), a temperature sensor (4) which is arranged and designed to sense a temperature of the stator (2), and a rotor-state-sensing sensor (5) which is held fixed with respect to the stator and is arranged and designed to sense a rotational speed and/or rotational position of the rotor (3), wherein the temperature sensor (4) and the rotor-state-sensing sensor (5) are implemented as subsystems (6, 7) of a common sensor system (8), wherein a first subsystem (6) which has the temperature sensor (4) is connected in a flexible fashion to a second subsystem (7) which has the rotor-state-sensing sensor (5). The invention also relates to a hybrid module (18) having this electric machine (1).

Description

Electrical machine with an inherent rotor position sensor with

integrated temperature sensor

The invention relates to an electrical machine for driving a motor vehicle, such as a car, truck, bus or other commercial vehicle, in particular for a drive train or for a wheel hub drive of a hybrid vehicle or egg Nes electric vehicle, with a stator, a rotatable relative to the stator rotor , a arranged to detect a temperature of the stator and trained temperature sensor and a arranged to detect a speed and / or rotational position of the rotor arranged and designed stator-fixed rotor condition detection sensor.

Generic electrical machines, such as those used in hybrid modules, are already well known from the prior art. DE 10 2017 1 16 232 A1, for example, discloses a hybrid module for a drive train of a motor vehicle with a rotor position sensor and a temperature sensor.

Thus, in principle, applications are already known in which various sensors are used, which record angular and / or rotational information of the electrical machine. In order to minimize the effects of torsion or tolerances in operation on the sensors, these are attached as close as possible to the electrical machine, with integration usually taking place in a housing of the electrical machine. However, it has turned out to be disadvantageous that in most cases the sensors have to be connected individually to the housing, for example via screw connections. As a result, the assembly effort is relatively high. Furthermore, there are various winding technologies for the coils of the electrical machines, for example hair-pin or rod-wave windings, in which temperature detection is relatively difficult, since these windings are very tightly wound or equipped and there is no temperature sensor between the windings or the respective wires can be inserted. It is therefore an object of the present invention to remedy the disadvantages known from the prior art and, in particular, to provide an electrical machine whose assembly effort is further reduced and which enables reliable detection of the temperature and the speed and / or rotational position .

This is achieved according to the invention in that the temperature sensor and the rotor state detection sensor are implemented as subsystems of a common sensor system / are also included in such subsystems, with a first subsystem having the temperature sensor being flexible / elastic / resilient with a second subsystem having the rotor state detection sensor ( mechanically) is connected.

By implementing such a sensor system as a structural unit / sensor module, consisting of the temperature sensor and the rotor condition detection sensor, the assembly effort is significantly reduced. Essentially, now after the stator of the electrical machine has been installed in a housing of the overall system and after the rotor of the electrical machine (such as a component detected by the rotor state detection sensor) has been installed, the sensor system as a whole, including the rotor state detection sensor and the temperature sensor, needs to be installed, for example on the cover of the electrical machine. In particular, the following advantages result from this type of design: fewer screw connections and less assembly effort; fewer tolerances due to reduced number of components; automated assembly processes; Contacting temperature sensor on a measuring surface can be implemented by a compensating element; less machining of the existing castings; only one cable duct; just a plug.

Further advantageous designs are claimed with the subclaims and explained in more detail below.

Accordingly, it is also advantageous if the first subsystem is electrically connected to a line connection of the sensor system via the second subsystem.

This further simplifies the structure. It is expedient if the first subsystem is connected to the second subsystem via an elastic element.

In this context, it is also advantageous if the first subsystem is flexibly or rigidly connected to a stator-fixed and / or housing-fixed component.

If the first subsystem is (electrically) connected to the second subsystem by means of at least one first line, the electrical supply and data transmission are likewise implemented in a simple manner.

The line structure is further simplified if the second subsystem is electrically connected to the line connection by means of at least one second line.

It has also proven to be advantageous if the temperature sensor is at least bipolar, ie. H. is connected to the second subsystem / the line connection via a two-pole (first) line. Several temperature sensors can be integrated.

It is also expedient if the rotor state detection sensor is at least four-pole, preferably four-pole or six-pole, / is electrically connected to the line connection via a four-pole / six-pole (second) line.

The line connection is therefore preferably at least six-pole, more preferably at least eight-pole. The lines of the rotor position sensor and the temperature sensor can also be implemented separately.

The temperature sensor further preferably has a contact element (temperature-sensitive element) which bears on a radial outside, a radial inside, a peripheral side or an axial side of a coil winding of the stator or is at least partially arranged within the coil winding / inserted into the coil winding. This results in an effective arrangement of the temperature sensor to precisely detect a temperature of the stator during operation. Furthermore, the invention relates to a hybrid module for a motor vehicle drive train, with an electrical machine according to the invention according to at least one of the embodiments described above and at least one clutch operatively connected to the rotor.

In other words, according to the invention, an inherent rotor position sensor (rotor state detection sensor) is integrated with an integrated temperature sensor. According to the invention, the rotor position sensor and the temperature sensor are integrated into a common inherent sensor system, which sensor system in turn has a subsystem having the rotor position sensor and a subsystem having the temperature sensor, which subsystems function independently of one another and are flexibly connected to one another.

The invention will now be explained in more detail with reference to figures, in which context various exemplary embodiments are shown in principle.

Show it:

Fig. 1 is a schematic view of an electrical Ma according to the invention

machine according to a preferred exemplary embodiment, the basic structure of the electrical machine being recognizable, in particular on the part of a sensor system,

Fig. 2 is a detailed perspective view of the electrical machine

1, wherein a component of the sensor system and a coil winding of a stator of the electrical machine are clearly visible,

3 shows a longitudinal sectional view of the electrical machine according to FIG. 2 along an axis of rotation of a rotor of the electrical machine,

Fig. 4 is a detailed view of the coil winding shown in Fig. 3 already shown to illustrate different possible positions egg nes temperature sensor, and Fig. 5a to 5d show several schematic representations of the electrical machine in different versions, different connections between a first subsystem having a temperature sensor and a second subsystem of the sensor system having a rotor state detection sensor being recognizable.

The figures are merely schematic in nature and serve only to understand the invention. The same elements are seen with the same reference numerals. The different features of the exemplary embodiments described in principle can also be freely combined with one another.

An electrical machine 1 according to the invention, as can be seen in its construction in principle in FIG. 1 in accordance with a preferred exemplary embodiment, is preferably part of a flybrid module 18 in its operation, which is shown in FIGS. 2 to 3 is partially recognizable. A flybrid module 18 is understood here to mean a special type of electric machine or a special electrical system. The electrical machine 1 is therefore preferably part of a motor vehicle drive train, such as a drive train of a hybrid vehicle or a purely electric vehicle. The electrical machine 1 is thus inserted as a drive machine in the drive train. In addition to the electrical machine 1, the hybrid module 18 typically has a plurality of couplings 19 which are used on the input or output side of a rotor 3. In principle, the electrical machine 1 can also be integrated directly in a wheel hub drive.

In Fig. 1, a housing 20 of the electrical machine 1 is shown schematically. A stator 2 is fixedly connected to the housing 20. The stator 2 is in particular with its coil winding 17, as can be seen, for example, in FIG. 2, firmly accommodated in the housing 20 Ge. A rotor 3 (rotor shaft) of the electrical machine 1 is rotatably mounted in the housing 20 relative to the stator 2. A sensor system 8 according to the invention is attached to the housing / stator. The sensor system 8 according to the invention has both a temperature sensor 4 (NTC or PTC) and a rotor condition detection sensor 5 in the form of a rotor position sensor. According to the invention, the temperature sensor 4 and the rotor state sensor 5 are each integrated in a separate subsystem 6, 7 of the sensor system 8. The two subsystems 6, 7 and thus the temperature sensor 4 and the ro torstatus-detection sensor 5 are interconnected.

In principle, possible connections between the two subsystems 6, 7 and between the first subsystem 6 and the stator 2 are shown in FIGS. 5a to 5d illustrate. 5a, a connection is illustrated, which, however, is not the subject of the invention and as a rigid (mechanical) connection between the in the subsystems 6, 7 and thus between the temperature sensor 4 integrated in the first subsystem 6 and that in the second subsystem 7th integrated rotor status detection sensor 5 is implemented. 5b there is a rigid connection between these subsystems 6, 7.

According to the embodiments of FIGS. 5c and 5d, the two subsystems 6, 7 are flexibly coupled / connected to one another. For this purpose, an elastic coupling element 10 is provided, which provides for the mechanical connection of the two subsystems 6, 7 and thus for a flexible recording of the temperature sensor 4 on the rotor state detection sensor 5.

Returning to FIG. 1, it should also be mentioned that the temperature sensor 4 is connected to a first line 11. This first line 11 is implemented as a two-pole line. The first line 11 leads from the first subsystem 6 to the second subsystem 7 and is in turn connected within this second subsystem 7 / passed through the second subsystem, with an output of the second subsystem 7 being further connected to a line connection 9 . The second Lei device 12 is implemented as a four-pole (alternatively six-pole) line. From the two-th subsystem 7 leads a single (six-pole (alternatively eight-pole) cable, forming the second and first lines 12, 1 1 to the line connection 9.

The rotor state detection sensor 5 / the second subsystem 7 is thus connected to one second line 12 connected. The second line 12 leads from the second subsystem 7 to the line connection 9. The line connection 9 implemented as a plug in turn has the ends of the two lines 11, 12 combined to form a main line 26. The main line 26 extends from the second subsystem 7 in a cable duct 25 of the sensor system 8 to the line connection 9.

This results in a particularly simple construction of the sensor system 8. In FIG. 1 and in FIGS. 5a to 5d, the transmissions of the measurement signals are identified by first arrows 27; a signal line / power supply is identified by further second arrows 28. The line connection 9 is further connected to power electronics 29 during operation in the usual way.

In Fig. 4, which is a detailed view of the coil winding 17 clearly shown in FIG. 3, different mounting positions of a contact element 13 of the temperature sensor 4 can be recognized by dots. Accordingly, it is possible in principle, with respect to a central axis of rotation 21 of the electrical machine 1 / the rotor 3, a contact element 13 of the temperature sensor 4 on a radial outside 14 of the coil winding 17, on a radial inside 15 of the coil winding 17, on one Arrange the peripheral side of the coil winding 17 or an axial side 16 on the coil winding 17. In any case, the contact element 13 is directly in surface contact with a wire 22 of the coil winding 17. Also, it is possible in principle to partially or completely insert the contact element 13 into a cavity 23 of the coil winding 17 between two wires 22. The contact element 13 is in turn metrologically coupled to the further structure of the temperature sensor 4 / the first subsystem 6 in order to forward a corresponding measurement signal.

As in Figs. 5a to 5d can also be seen, the stator 2 can be coupled via the contact element 13 to the further structure of the first subsystem 6 rigidly (FIGS. 5a and 5d) or flexibly (FIGS. 5b, 5c).

The rotor state detection sensor 5, as can also be seen in principle in FIG. 2, is firmly attached to the stator 2. The rotor condition detection sensor 5 interacts with a rotation test coupled to the rotor 3 encoder 24. The sensor 24 is preferably implemented as a corresponding sensor wheel and generates a signal corresponding to the rotational position at the rotor state detection sensor 5. The rotor state detection sensor 5 is primarily designed to detect the rotational position, ie the angular position of the rotor 3. In a further embodiment, the rotor state detection sensor 5 is simultaneously designed to detect a speed of the rotor 3.

In other words, the inventive solution for an electrical machine 1 (EM) is to integrate two sensor systems 6, 7 in an overall sensor system 8, which further comprises an RPS subsystem 7 and an NTC subsystem 6 exists, which continue to work independently of each other. The advantage essentially consists in the integration of the overall system 8, since it is now possible to integrate the overall sensor system 8 in one, and no longer both, independently and one after the other.

In the sense of the inventive solution (according to FIG. 1), the temperature sensor 4 (for example an NTC or PTC) is combined with an RPS sensor 5. The temperature sensor can either be permanently or flexibly integrated into the RPS sensor. In any case, a contact surface must be established between the temperature sensor 4 and the winding 17 of the electric machine 1 in order to record the temperature. This is difficult to achieve with a fixed connection, since axial, radial and / or tangential tolerances have to be compensated for. The contact surface produced, ideally in the area of the windings 17, can be produced at any point on the electric machine 1 (stator 2), for example radially, tangentially or axially (FIG. 4). The contact surface of the temperature sensor can thus lie radially below the electric machine winding 17, radially above, inside the windings 17 and axially outside the windings 17. Since a fixed connection between the temperature sensor and the RPS sensor makes it difficult to establish a contact surface with the electric machine (windings ) can be realized, a flexible arrangement of temperature sensor 4 and RPS sensor 5 is implemented. This flexible connection can be made, for example, by a suitable flexible or elastic element 10. In Figs. 5a to 5d different combinations of such a flexible connection are shown. The contact area of the The temperature sensor can act actively or passively on the measuring surface to be recorded. The temperature sensor must be in a defined and fixed position on the winding. The rotor position sensor can be, for example, the functional principle of a resolver, eddy current sensor, GMR, etc. Novel sensors are also conceivable. RPS stands for "rotor position sensor" in English and is referred to in the German translation as RLS / rotor position sensor. This integration also allows the number of components to be reduced, since, for example, a cable duct 25 or a common plug 9 can be used. The temperature sensor is usually 2-pole, ie it has two signal lines. The RPS sensor is usually 4- or 6-pin. In the sense of the invention, a common connector 9 with 6 or 8 poles can now be used. This results in a cost and space advantage. Due to the joint integration, the two signal lines of the temperature sensor 4 are guided through the RPS sensor 5 to the power electronics 29. In the RPS sensor 5, this is done by a correspondingly expanded circuit board / PCB. Outside the sensor 5 by appropriate cables.

According to the invention, an assembly method is simplified in the following steps:

1 . Mounting the EM stator 2 in the housing 20 of the overall system;

2. Assembly of the EM rotor 3 including the RPS rotor (encoder 24);

3. Installation of the RPS sensor 5 including the temperature sensor 4 (as Ge

overall sensor system 8) on the cover 20 of the electrical machine 1.

The signal lines are brought forward on the cover 20. The contact to the power electronics 29 is “blind”. Reference list electrical machine

stator

rotor

Temperature sensor

Rotor condition detection sensor

first subsystem

second subsystem

Sensor system

Line connection

element

first line

second line

Contact element

Outside

inside

axial side

Coil winding

Hybrid module

clutch

casing

Axis of rotation

wire

cavity

giver

Cabel Canal

Main line

first arrow

second arrow

Power electronics

Claims

1. Electrical machine (1) for driving a motor vehicle, with a stator (2), a rotor (3) rotatable relative to the stator (2), a temperature sensor (4) arranged and designed to detect a temperature of the stator (2) ) and a rotor state detection sensor (5) arranged and designed to detect a speed and / or rotational position of the rotor (3), characterized in that the temperature sensor (4) and the rotor state detection sensor (5) as subsystems (6, 7) of a common sensor system (8), a first subsystem (6) having the temperature sensor (4) being flexibly connected to a second subsystem (7) having the rotor state detection sensor (5).

2. Electrical machine (1) according to claim 1, characterized in that the first subsystem (6) via the second subsystem (7) is electrically connected to a line connection (9) of the sensor system (8).

3. Electrical machine (1) according to claim 1 or 2, characterized in that the first subsystem (6) via an elastic element (10) with the two-th subsystem (7) is connected.

4. Electrical machine (1) according to one of claims 1 to 3, characterized in that the first subsystem (6) is flexibly or rigidly connected to a stator-fixed and / or housing-fixed component.

5. Electrical machine (1) according to one of claims 1 to 4, characterized in that the first subsystem (6) by means of at least a first line (11) is connected to the second subsystem (7).

6. Electrical machine (1) according to one of claims 1 to 5, characterized in that the second subsystem (7) by means of at least one two-th line (12) with the line connection (9) is electrically connected.

7. Electrical machine (1) according to one of claims 1 to 6, characterized in that the temperature sensor (4) is at least bipolar ausgebil det.

8. Electrical machine (1) according to one of claims 1 to 7, characterized in that the rotor state detection sensor (5) is at least four-pole.

9. Electrical machine (1) according to one of claims 1 to 8, characterized in that the temperature sensor (4) has a contact element (13) on a radial outside (14), a radial inside (15), a peripheral side or an axial side (16) of a coil winding (17) of the stator (2), or is at least partially arranged within the coil winding (17).

10. Hybrid module (18) for a motor vehicle drive train, with an electrical machine (1) according to one of claims 1 to 9 and at least one with the rotor (3) operatively connected clutch (19).