EP3959801A1

EP3959801A1 - Electric machine

Info

Publication number: EP3959801A1
Application number: EP20718542.2A
Authority: EP
Inventors: Christian Silvery; Mike CZERLEWITZ
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2019-04-26
Filing date: 2020-03-26
Publication date: 2022-03-02
Also published as: DE102019121190A1; US20220200411A1; WO2020216401A1; CN113728536A

Abstract

The invention relates to an electric machine comprising a stator (2) having a winding (3), and at least one temperature sensor arrangement (16) comprising a temperature sensor (20) for detecting the temperature in the region of the winding (3). The ends (7, 7a) of at least one part of the conductor (4) protrude from the winding (3). One part of said ends (7, 7a) is connected to an axial or radial interconnection ring (8) placed on the winding (3). The temperature sensor arrangement (16) is arranged on or in the interconnection ring (8) and the temperature sensor is thermally coupled to at least one conductor (15).

Description

Electric machine

The invention relates to an electrical machine, comprising a stator with a winding, and at least one temperature sensor arrangement comprising a temperature sensor for detecting the temperature in the area of the winding.

Electrical machines include a rotor and a stator and are used in different areas of application. The use of electrical machines for electric hybrid vehicles and electric vehicles or for hub drives is only mentioned as an example. If such an electrical machine is used as a drive machine, it is mostly designed as an internal rotor, which means that the stator surrounds the internal rotor. A wandering magnetic field is generated via the stator, which causes the rotor to rotate. For this purpose, the stator has a winding consisting of a large number of conductors, the conductors being assigned to one or usually several phases. The winding is guided around the stator teeth in a manner known per se.

Not only the number of phases goes into the design of the winding geometry, but also the number of wires per phase as well as the number of wires per slot within the stator toothing and the number of pole pairs. This variety of conductors and winding parameters creates a complex network of conductors that is built up using different winding technologies. Examples include the so-called hairpin or bar wave winding. Here, the conductors are formed by means of rods bent in a U-shape, which are put together to form a winding basket. The conductors are laid on a plurality of radial levels, with the conductors moving from level to level. You are to form quasi mäanderförmi ger, circumferential conductor at their ends to be connected accordingly, which is usually done by welding the conductor ends that are adjacent to each other. The conductor ends converge at one point or one winding side in the form of a so-called star, where they are connected to one another. In this area, the connection of the individual phases to an external power supply is also supply, i.e. a power connection that is used to generate the magnetic field.

During the operation of the electrical machine, the temperature of individual components is to be monitored, including appropriate temperature sensors such. B. PTC or NTC sensors can be used. One area in which the temperature is to be recorded is that of the winding, since one of the hottest points of the stator of the electrical machine prevails in the area of the winding, where a temperature sensor can be installed. The hottest point of the stator is namely in the hairpin or rod wave winding area, precisely in the axial center of the laminated core.

However, since this point cannot be reached in order to integrate a temperature sensor, the outer area of the winding is selected. For this purpose, the temperature sensor is installed inside the stator, which means that it usually has to be installed at an early stage of the manufacturing process. In order to record the temperature in the winding area as precisely as possible, it is desirable to attach the temperature sensor as close as possible to or on the winding or the winding head, since media flows in the interior, for example water, air, oil, etc., can impair the temperature measurement and therefore increase Distance between the temperature sensor and the winding or the winding head, the measurement becomes imprecise. The arrangement of the temperature sensor, in particular on a particularly tightly wound or compactly wound winding, such as a hairpin or a bar wave winding, is particularly complicated.

The invention is based on the problem of specifying a comparatively improved electrical cal machine.

To solve this problem, the invention provides for an electrical machine of the type mentioned at the outset that the ends of at least some of the conductors protrude beyond the winding, some of these ends being connected to an interconnection ring placed axially or radially on the winding, the Temperature sensor arrangement arranged on or in the interconnection ring and the temperature sensor is thermally coupled to at least one conductor there. The electrical machine according to the invention provides for the temperature sensor to be arranged directly on the connection ring, so that the temperature of a conductor there, which, as it were, connects the winding conductor as a conductor bridge, is measured via the temperature sensor. This makes it possible to measure the temperature not only in a radially or axially outer area of the stator winding, which can be subjected to a different operating temperature due to increased heat dissipation, but rather integrated in the interconnection ring directly in the area of the origin. Because the temperature sensing is integrated in the connection ring itself, an optimal heat transfer between the current-carrying and therefore warming conductor, i.e. the conductor rail or cable bridge, usually a copper rail, and the temperature sensor is achieved, so that undesired error influences and measured value deviations are reliably avoided. In addition, due to the integration in the interconnection ring, which is a separately configurable element to be placed on the winding as an independent component, the radial and axial position of the temperature sensor can be defined reliably and with reproducible accuracy.

The connection ring expediently has a housing in which the conductor is received, the temperature sensor arrangement being arranged on or in the housing. The arrangement of the temperature sensor arrangement on or in the housing ensures the simple and, in particular, reproducible fixing of the temperature sensor arrangement in a simple manner, since a defined fastening interface can be realized. In particular, the arrangement in the housing also offers protection against any external influences, so that, for example, no media flows such as water, air, oil etc. can reach the temperature sensor, which can be an NTC or PTC resistance element, for example .

The temperature sensor arrangement itself preferably comprises a carrier, the temperature sensor being arranged in the region of a carrier side. The temperature sensor arrangement will lose sufficient stability via this carrier. The temperature sensor itself can be arranged on a sensor carrier, which is arranged on the carrier. This sensor carrier, for example an elongated plate Plastic, for example, is used to secure the temperature sensor in place. The temperature sensor is also interconnected on the sensor carrier via suitable connecting lines to form a continuing cable.

For secure and positionally accurate fixing of the sensor carrier on the carrier itself, the carrier preferably has a receptacle that is compatible with the shape of the sensor carrier and into which the sensor carrier can be inserted in a form-fitting manner.

According to a particularly advantageous development, the carrier itself forms part of a housing, the temperature sensor being positioned on an open side of the housing.

According to an advantageous development of the invention it can be provided that the temperature sensor is attached to the conductor via at least one spring element. This spring element, which acts on the carrier, for example, ensures that the temperature sensor is always pressed into thermal contact with the conductor, i.e. the copper bridge, and that a reproducible thermal coupling is always ensured for exact temperature detection.

It is particularly preferred that a detachably connectable cover to the carrier is provided, the carrier being movable relative to the cover and the spring element being arranged between the cover and the carrier. This cover forms, as it were, a second part of the housing, with it in particular having the function of an abutment for the spring element. The spring element is clamped between the cover and the carrier. The temperature sensor or the sensor carrier is arranged on the opposite carrier side, exposed to the outside of the housing, so that the carrier that is movable relative to the cover and thus also the sensor is pressed against the conductor of the connection ring.

Alternatively, it is conceivable that the spring element is also arranged between the carrier and the sensor carrier itself. In this case, the carrier forms the abutment for the spring element; a housing-like cover is not provided here. In this case, the carrier is to be fixed directly in a suitable manner, unlike the embodiment described above, in which the cover is to be fixed in position after the carrier is movable relative to the cover.

A curved leaf spring, which is preferably fixed to the carrier, is preferably used as the spring element, if provided, but can also be fastened to the cover.

To fix the temperature sensor arrangement on or in the interconnection ring or its housing, a latching or clamping connection is particularly preferably provided for detachable fixing. This releasable fixation enables the assembly by simple locking or clamping in a simple manner, but also simple disassembly is possible. If a housing or a cover is used, corresponding Rastvor jumps or the like are provided on the housing or cover, which snap into corresponding locking receptacles on the connection ring or connection ring housing. Since the cover is fixed, the carrier can be moved relative to the cover. If no cover is used, but only a carrier, this must be fixed on the ring side via corresponding locking elements interconnection, since the sensor carrier is then movable relative to the carrier for springing, provided such a spring element is provided in this case, which is not mandatory .

The invention is explained below using exemplary embodiments with reference to the drawings. The drawings are schematic representations and show:

FIG. 1 shows a basic illustration in the form of a partial view of an electrical machine according to the invention,

Figure 2 is a perspective view of a temperature sensor device with temperature sensor and sensor carrier,

Figure 3 is an exploded view of a carrier and a spring element, FIG. 4 shows the assembled arrangement of carrier and spring element,

FIG. 5 shows the arrangement from FIG. 4 with the temperature sensor device attached thereto,

FIG. 6 shows an exploded view of the arrangement from FIG. 6 with an additional

Cover,

FIG. 7 shows a sectional view through the mounted temperature sensor arrangement

Figure 6 with the lid attached,

Figure 8 is a detailed view of the interconnection ring with not yet attached

Temperature sensor arrangement, and

FIG. 9 shows a sectional view through the arrangement from FIG. 8 with a fixed temperature sensor arrangement.

FIG. 1 shows, in the form of a partial view, a basic representation of an electrical machine 1 according to the invention, comprising a stator 2 with a winding 3 comprising a plurality of conductors 4, which are assigned to three separate phases in the example shown. Each conductor 4 is designed, as it were, as a U-shaped bracket, a large number of such U-shaped conductors, often also called hairpins, being plugged together to form the winding 3, which can also be referred to as a winding cage. The large number of conductors 4 define different radial planes R, as shown in FIG. For this purpose, the conductors 4 extend, depending on the winding scheme, from one radial plane to another radial plane, for example an adjacent radial plane, in the area in which they are connected to the conductor ends of the corresponding adjacent conductors continuing the phase conductor.

The conductors 4 are guided or bent and laid in such a way that corresponding recesses 5 result which extend radially so that corresponding

Stator teeth 6 engage in these recesses 5, respectively the corresponding Lei ter 4 are wound between the grooves of the stator teeth 6. The basic structure such a stator 2 or a winding 3 wound from the separate brackets described is basically known.

In the case of the stator 2 according to the invention, the ends 7 of the conductors 4 project axially, as long as the ends 7 are positioned on the inner circumference and / or the outer circumference of the annular winding 3, i.e. they protrude axially from the winding 3 . These ends 7 are associated with individual conductors 4, which in turn are assigned un different phases, which is why the conductor ends are to be wired according to the laying scheme of the conductor 4. For this purpose, a connection ring 8 is used, which in this example is placed axially on the end face of the winding 3 and is arranged between tween the conductor ends 7, or engages between them. The interconnection ring 8 comprises, as will be discussed below, one or more corresponding conductors in the form of cable bridges as well as at connection sections 9 which protrude to the side from the housing 10 of the interconnection ring 8 and after the interconnection ring 8 has been inserted between the conductor ends 7 are positioned exactly next to the corresponding conductor ends 7 with which they are to be connected. The connection is made by simple welding, so that all conductors 4 are correctly and phase-specifically connected to one another when they are connected.

Furthermore, a power supply 11 is provided, which is arranged radially next to the winding 3 in the area of its axial end, that is to say the winding head. The power supply 11, also referred to as the HV terminal, comprises a housing 12 in which corresponding busbars 13 are arranged, the connection terminals 14 of which protrude from the housing 12.

In the present case, as described, a three-phase stator is shown, which is why three such connection terminals 14 are also provided in the example shown.

Each connection terminal 14 is to be connected to one phase of the winding 3. This is implemented in a simple manner in the exemplary embodiment shown in that two conductor ends 7a per phase are guided or bent radially outwards, as FIG. 1 clearly shows. As already described, one or more conductors 15 are accommodated in the interior of the housing 10 of the interconnection ring 8, which conductors serve as line bridges and are designed in the form of busbars or busbars. In the example shown, only one such conductor 15 is shown in dashed lines. According to the invention, a temperature sensor arrangement 16 is also provided, which is received on or in the housing 10 of the interconnection ring 8, for which in the example shown only a recess 17 is shown in principle, in which the temperature sensor arrangement 16 is inserted. The arrangement is such that a temperature sensor, which will be discussed below, is brought into thermal contact with a conductor 15, preferably the neutral conductor, so that its temperature is measured, and information about the winding temperature can be obtained. This means that the inventive arrangement of the temperature sensor arrangement 16 on or in the interconnection ring or its housing itself enables a direct temperature measurement at this location.

Figure 2 shows a temperature sensor device 18 as part of the temperature sensor arrangement 16. The temperature sensor device 18 comprises a sensor carrier 19 on which the actual temperature sensor 20, for example an NTC or PTC sensor, is attached and via connecting lines 21 with a corresponding continuing cable 22 connected is. A shrink tube 23 is pulled over the sensor carrier 19 and the temperature sensor 20 as well as the connecting line 21 in order to protect the arrangement. The sensor carrier 19 is elongated, so it leads out flake, it is, for example, a plastic plate.

FIG. 3 shows an exploded view of a carrier 24 and a spring element 25 in the form of a leaf spring 26. The carrier 24 serves, which will be discussed below, to receive and hold the temperature sensor device 18 from FIG.

On one side of the carrier 24 there are fastening means 27 for arranging and fastening the leaf spring 26, which likewise has corresponding fastening means 28 in the form of latching elements or corresponding form-fitting elements. hen. As shown by the arrow P1, the leaf spring 26 is pushed onto the carrier 24 from the side so that it is clamped between the fastening means 27 there on the one hand and is also locked in place on the other hand, as FIG. 4 shows.

This arrangement from FIG. 4 is then equipped with the temperature sensor device 18, see FIG. 5.For this purpose, the sensor carrier 19 is passed through an insertion opening 29 provided on the carrier, so that it is virtually on the outer lower side of the carrier 24, which has a corresponding recess 30 has for receiving the sensor carrier is positioned. As FIG. 5 shows, the cable 22 runs out of the insertion opening 29 and can be continued. This means that after the arrangement on the carrier 24, the temperature sensor 20 is arranged in the area of the open underside.

FIG. 6 also shows a cover 31, which is to be snapped onto the carrier 24 via a suitable latching connection, not shown in detail, in an exploded view. Like the carrier 24, the cover 31 is also made of plastic. The cover can be seen, see arrow P2, on the side on which the leaf spring 26 is arranged, so that after the cover 31 has been mounted, see FIG. 7, the leaf spring 26 is braced between the cover 31 and the carrier 24 . The carrier 24 can be moved somewhat relative to the cover 31, as far as its latching connection permits. This it is necessary because the sensor carrier 19 or the temperature sensor 20 is sprung against the conductor 15 and pressed via the leaf spring 26.

Corresponding latching elements 32 are provided on both sides of the cover 31, see FIG. 6 (FIG. 6 shows only one side thereof), via which latching elements 32 the cover 31 and with it the entire temperature sensor arrangement 16, as shown in FIG. 7, on the connection ring 8 or its housing 10 is fixed.

This process is shown in FIG. 8. This shows a section of the interconnection ring 8 or its housing 10, with the recess 17 already mentioned above, into which the temperature sensor arrangement 16, as shown by the arrow P3, is inserted. In the area of the recess 17 the conductor 15, for example the neutral conductor, is exposed. If the temperature sensor arrangement 16 is now pressed into the recess 17, the locking elements 32 snap into suitable locking receptacles 33 on the housing 10 in the area of the recess 17 when the final assembly position is reached, via which the temperature sensor arrangement 16 is fixed in position on the one hand, but also on the other if necessary, can be released again and removed or replaced for maintenance purposes.

After snapping in the latching connection, the temperature sensor arrangement 16 is fixed in a reproducible position, see Figure 9. The temperature sensor device 18 or the temperature sensor 20 is sprung against the conductor 15 via the leaf spring 26, as Figure 9 clearly shows, so that an optimal thermal contact and thus a very good thermal coupling is given. By springing the temperature sensor on the one hand, a reproducible thermal contact can be realized, and on the other hand, corresponding geometric tolerances can easily be compensated for. At the same time, the measuring arrangement is also protected against external influences such as media flows, etc. due to the encapsulation in the housing or the corresponding arrangement on the interconnection ring housing.

Reference list for electrical machine

stator

Winding

ladder

Recess

Stator tooth

End of ladder

Interconnection ring

Connection section

casing

Power supply

casing

Busbar

Connection terminal

ladder

Temperature sensor arrangement

Recess

Temperature sensor device

Sensor carrier

Temperature sensor

Connecting line

electric wire

Shrink tubing

carrier

Spring element

Leaf spring

Fasteners

Insertion opening

Recess

cover 32 locking element

33 Locking receptacle R radial plane P1 arrow

P2 arrow

P3 arrow

Claims

1. Electrical machine comprising a stator (2) with a winding (3), and at least one temperature sensor arrangement (16) comprising a temperature sensor (20) for detecting the temperature in the area of the winding (3), characterized in that the ends ( 7, 7a) at least part of the conductor (4) protrude beyond the winding (3), some of these ends (7, 7a) being connected to a connection ring (8) placed axially or radially on the winding (3), wherein the temperature sensor arrangement (16) is arranged on or in the connection ring (8) and the temperature sensor (20) is thermally coupled to at least one conductor (15) there.

2. Electrical machine according to claim 1, characterized in that the interconnection ring (8) has a housing (10) in which the conductor (15) is received, the temperature sensor arrangement (16) on or in the housing (10) is arranged.

3. Electrical machine according to claim 1 or 2, characterized in that the temperature sensor arrangement (16) comprises a carrier (24), wherein the temperature sensor (20) is arranged in the region of a carrier side.

4. Electrical machine according to claim 3, characterized in that the temperature sensor (20) is arranged on a sensor carrier (19) which is arranged on the carrier (24).

5. Electrical machine according to claim 4, characterized in that on

Support (24) a receptacle (30) compatible with the shape of the sensor support (19) is provided.

6. Electrical machine according to claim 4 or 5, characterized in that the carrier (24) forms part of a housing, the temperature sensor (20) being positioned on an open housing side.

7. Electrical machine according to one of the preceding claims, characterized in that the temperature sensor (20) is spring-loaded via at least one Federele element (25) against the conductor (15).

8. Electrical machine according to claim 6 and one of claims 3 to 5, characterized in that a detachably with the carrier (24) connectable cover (31) is provided, the carrier (24) relative to the cover (31) movable bar and the spring element (25) is arranged between the cover (31) and the carrier (24), or that the spring element (25) is arranged between the carrier (24) and the sensor carrier (19).

9. Electrical machine according to one of claims 6 to 8, characterized

shows that the spring element (25) is a curved leaf spring (26), which is preferably fixed on the carrier (24).

10. Electrical machine according to one of the preceding claims, characterized in that the temperature sensor arrangement (16) is detachably arranged via a latching or clamping connection on the interconnection ring (8).