Motor

Abstract

The invention relates to an electric machine, comprising a stator (2) with a winding (3) and at least one temperature sensor arrangement with a temperature sensor (19) for detecting the temperature in the region of the winding. An end (7, 7a) of at least a portion of a conductor (4) protrudes from the winding (3). A portion of the end (7, 7a) is connected to an axial or radial interconnection ring (8) arranged on the winding (3). The temperature sensor arrangement (16) is arranged on the conductor (15) and the temperature sensor is thermally coupled to at least one conductor (15).

Description

Technical Field

[0001] The invention relates to an electric machine comprising a stator with a winding and at least one temperature sensor arrangement with a temperature sensor for detecting the temperature in the region of the winding. Background Art

[0002] Electric machines comprise a rotor and a stator and are used in a variety of application areas. The use of electric machines for electric hybrid vehicles and electric vehicles or for wheel hub drives is mentioned merely as an example. If such electric machines are used as drive machines, they are usually designed as an internal rotor, i.e. the stator surrounds the internal rotor. A moving magnetic field is generated via the stator, which causes the rotor to rotate. For this purpose, the stator has a winding consisting of a plurality of conductors, wherein the conductors are assigned to one phase or generally more than one phase. The winding is guided around the stator teeth in a manner known per se.

[0003] The design of the winding geometry includes not only the number of phases, but also the number of lines of each phase and the number of lines of each slot in the stator tooth and the number of pole pairs. Such multiple conductors and winding parameters create a complex conductor network, which is constructed using a variety of winding technologies. Examples include hairpin windings or strip wave windings. Here, the conductor is formed by means of a rod bent into a U-shaped shape, which is placed together to form a winding frame. The conductor is laid on multiple radial layers, and it can be said that the conductor moves from one layer to another. In order to form these circumferential conductors, which can be said to be tortuous, these conductors are connected correspondingly at their ends, which is usually done by welding the conductor ends adjacent to each other. The conductor ends converge at one point or converge on one winding side in the form of a so-called star, and the conductor ends are connected to each other at this point or on this winding side. In this area, each phase is connected to an external power supply, that is, an electric power connection is made for generating a magnetic field.

[0004] During the operation of the motor, the temperature of the various components must be monitored, for which corresponding temperature sensors, such as PTC or NTC sensors, are used. One area where the temperature is recorded is the area of ​​the winding, because one of the hottest points of the stator of the motor is present in the area of ​​the winding, in which the temperature sensor can be installed. This is because the hottest point of the stator is located in the hairpin winding or strip wave winding area, just in the axial middle of the laminated core. However, since this point cannot be reached to integrate the temperature sensor, the outer area of ​​the winding is selected. For this reason, the temperature sensor is installed inside the stator, which means that the temperature sensor usually has to be installed in the early stages of the production process. In order to record the temperature of the winding area as accurately as possible, it is desirable to attach the temperature sensor as close to the winding or winding head as possible or to the winding or winding head, because the medium flowing inside, such as water, air, oil, etc., will affect the temperature measurement, and therefore the measurement will become inaccurate as the distance between the temperature sensor and the winding or winding head increases. The arrangement of temperature sensors, in particular on particularly tightly wound or compactly wound windings such as hairpin windings or strip-shaped wave windings, is particularly complex. Summary of the invention

[0005] The invention is based on the problem of specifying an electric machine which is improved in comparison.

[0006] In order to solve this problem, in an electric machine of the type described above, the invention provides that the ends of at least some of the conductors protrude beyond the winding, wherein some of these ends are connected to interconnecting rings arranged axially or radially on the winding, wherein the temperature sensor arrangement structure is arranged on the conductor and the temperature sensor is thermally coupled to the conductor.

[0007] In the motor according to the invention, the temperature sensor arrangement is arranged independently of the connecting ring on the conductor, which is usually in the form of a conductor rail or busbar, and is either arranged between the connecting ring and the circuit electronics or on the so-called special wire. This is a conductor that is not designed like all common hairpins in terms of geometry and position. The temperature sensor can be designed, for example, as a PTC or NTC measuring sensor in thermal contact with the conductor. This enables direct temperature detection on such a conductor or conductor rail through which current flows and thus becomes hot during operation, and thus enables direct temperature detection in the immediate winding area, wherein, by fixing the temperature sensor arrangement on the conductor itself, the radial and axial position of the temperature sensor arrangement becomes reliable and endowed with repeatable accuracy, and thus the temperature sensor itself becomes reliable and endowed with repeatable accuracy. By integrating the temperature detection directly on this conductor, which is usually a copper conductor or copper strip, an optimal heat transfer is achieved, so that undesirable error influences and measured value deviations are reliably avoided. Furthermore, in the manner according to the invention it is not only possible to measure the temperature in a radially or axially outer edge region of the stator winding, which is subject to a different operating temperature than the current conductors, but due to the increased heat dissipation the measurement according to the invention is now carried out directly at this radially or axially outer edge region.

[0008] The temperature sensor arrangement itself advantageously has a housing in which the temperature sensor is accommodated and through which the conductor extends. The housing, which is arranged on the conductor, serves on the one hand to encapsulate the temperature sensor and on the other hand also to encapsulate the measuring point, thereby allowing very good protection against external influences that have a negative effect on the measurement, such as media flows of water, oil, air, etc., which can advantageously be avoided, and allows very precise measurements.

[0009] The housing itself advantageously has a carrier, to which the temperature sensor is fixed, and a cover, which can be attached to the carrier in a releasable manner and which closes the housing. The housing is thus divided into two parts, so that the housing can be easily placed on a conductor extending through the housing or can be placed around a conductor. The cover is advantageously attached to the carrier via a latching or clamping connection, which enables a very simple connection or a simple closing of the housing. In addition to the simple assembly, the latching or clamping connection also enables a very simple disassembly when performing maintenance or repair work, that is to say the temperature sensor arrangement can be easily replaced if necessary.

[0010] The temperature sensor itself is preferably arranged on a sensor carrier, which has a form-fitting contour, or a shrink tube with a form-fitting contour is drawn onto the sensor carrier, and a counter-contour that receives the form-fitting contour is provided on the carrier. Such corresponding contours of the sensor carrier or shrink tube and carrier enable a reproducible, precisely positioned arrangement of the sensor carrier or the temperature sensor on the carrier, which also simplifies assembly.

[0011] According to a particularly advantageous development of the invention, a spring element is provided for spring-loading the temperature sensor against the conductor. The spring element ensures that the temperature sensor always has a defined thermal coupling with the conductor and any geometric tolerances can be easily compensated. This means that the temperature sensor on the carrier or the sensor carrier can be slightly moved so that the temperature sensor or the sensor carrier can be pressed against the spring element.

[0012] In this case, the spring element is preferably arranged on the cover and positioned laterally adjacent to the sensor carrier when the cover is mounted, the conductor extending on the opposite side of the sensor carrier. This means that when the cover is closed or attached, the spring element is pressed against the sensor carrier or against a shrink tube enclosing the sensor carrier, so that the arrangement with the temperature sensor is pressed against the conductor. As described above, the sensor carrier is arranged on the carrier in a slightly movable manner, so that the spring element spring-loads the conductor and also simultaneously compensates for any small tolerances.

[0013] A bent leaf spring is preferably used as spring element, which is fastened to the cover in a suitable manner by means of suitable fastening means, such as latching sections or clamping sections.

[0014] The housing of the temperature sensor arrangement itself is preferably made of plastic, so that it can be produced in a very simple and cost-effective manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention is described below based on exemplary embodiments with reference to the accompanying drawings. The accompanying drawings are schematic illustrations, in which:

[0016] Figure 1 A schematic diagram of an electric machine according to the invention is shown in the form of a partial view,

[0017] Figure 2 shows a perspective view of a temperature sensor device comprising a sensor carrier and a temperature sensor,

[0018] Figure 3 shows a perspective view of a carrier as part of a temperature sensor arrangement,

[0019] Figure 4 shows a temperature sensor device mounted on a carrier,

[0020] Figure 5 shows a temperature sensor arrangement attached to a conductor whose temperature is to be detected,

[0021] Figure 6 shows a perspective view of a cover for attachment to a carrier,

[0022] Figure 7 shows a temperature sensor arrangement according to the invention in an open state, wherein the carrier is arranged on the conductor and the cover is separated,

[0023] Figure 8 Shown from the other side Figure 7 The layout structure in

[0024] Fig. 9 shows a closed temperature sensor arrangement, and

[0025] Fig.10 Shown through the Fig. 9 Cross-sectional view of a temperature sensor arrangement with a continuous conductor. DETAILED DESCRIPTION

[0026] Figure 1 A schematic illustration of an electric machine 1 according to the invention is shown in the form of a partial view, comprising a stator 2 and a winding 3, which comprises a plurality of conductors 4, which in the example shown are assigned to three individual phases. Each conductor 4 is designed as a U-shaped support, so to speak, wherein a plurality of such U-shaped conductors 4, which are also often referred to as hairpin conductors, are plugged together to form a winding 3, which can also be referred to as a winding support. Figure 1 As shown in , the plurality of conductors 4 define different radial planes R. To this end, the conductors 4 extend from one radial plane to another radial plane, such as adjacent radial planes, according to the winding diagram in the following areas: in the areas where the conductors are connected to the conductor ends of the corresponding adjacent conductors 4 to continue the phase conductor.

[0027] The conductors 4 are guided or bent and laid such that corresponding recesses 5 are produced, which extend radially such that corresponding stator teeth 6 engage in these recesses 5 or such that corresponding conductors 4 are wound between corresponding grooves of the stator teeth 6. The basic structure of such a stator 2 or winding 3 wound from a separate support as described is basically known.

[0028] In the stator 2 according to the invention, the ends 7 of the conductors 4 protrude axially, i.e. the ends of the conductors protrude axially from the winding 3, insofar as the ends 7 terminate at the inner and outer circumference of the annular winding 3, respectively. These ends 7 are associated with individual conductors 4, which in turn are assigned to different phases, which is why the conductor ends must be connected according to the layout diagram of the conductors 4. For this purpose, an interconnection ring 8 is used, which in the example shown is axially placed on the end face of the winding 3 and is arranged between the conductor ends 7 or engaged between the conductor ends. As will be discussed below, the interconnection ring 8 comprises a plurality of corresponding conductors, which can also be called conducting bridges and are formed by conductor rails or busbars, usually made of copper, and a connecting section 9, which protrudes to the side from the housing 10 of the interconnection ring 8 and, after the insertion of the interconnection ring 8, is positioned in a precisely positioned manner adjacent to the corresponding conductor end 7 to which the connecting section is to be connected. The connection is made by simple welding, so that all conductors 4 are correctly and phase-specifically interconnected when they are connected. Furthermore, a current source 11 is provided which is arranged radially near the winding 3 in the region of its axial ends. The current source 11, also referred to as an HV terminal, comprises a housing 12 in which corresponding conductor rails 13 are arranged which protrude from the housing 12 together with their connection terminals 14.

[0029] In the present case, as described, a 3-phase stator is shown, which is why in the example shown also three such connecting terminals 14 are provided.

[0030] Each connection terminal 14 is to be connected to one phase of the winding 3. This is achieved in a simple manner in the exemplary embodiment shown, wherein the two conductor ends 7a of each phase are guided or bent radially outwards, such as Figure 1 shown.

[0031] As described, a plurality of corresponding conductors forming a conducting bridge are arranged inside the housing 10 of the interconnection ring 8, of which only one such conductor 15 is shown in dashed lines in the exemplary embodiment shown. A temperature sensor arrangement 16 is arranged on this conductor, that is to say connected directly to the conductor 15, in order to directly measure the conductor temperature as a measure for the winding temperature.

[0032] The temperature sensor arrangement 16 comprises a temperature sensor device 17, such as Figure 2 . The temperature sensor device 17 has a sensor carrier 18, on which a temperature sensor 19 and a corresponding connection line 20 leading to a continuous cable 21 are arranged. A shrink tube 22 is drawn on the sensor carrier 18, which has a defined form-fitting contour 23 and has two suitable undercuts in the front end, which are used for mounting and positioning the sensor device 18 on a carrier 24.

[0033] Such a carrier 24 is Figure 3 2 is shown in a perspective view. The carrier 24 is made of plastic and has a cable holding section 25 and an engagement profile section 26 for the form-fitting profile 23. In addition, as will be discussed below, two axially aligned openings 27 are provided, through which the conductor 15 extends into and out of the housing formed by the carrier 24 and the cover to be described below. Further lateral openings 28, 29 to be discussed below are also closed by means of the cover.

[0034] Figure 4 An arrangement is shown in which the temperature sensor device 17 is attached to a carrier 24. As can be seen, the cable 21 extends through the cable holding section 25, while the form-fitting contour 23 engages in the engagement contour section 26. The arrangement is such that the sensor carrier 18 is vertical, so to speak, so that the temperature sensor 19 points toward the interior of the carrier 24.

[0035] The arrangement is now connected to the conductor 15, ie the conductor rail 15. The arrangement is inserted from above into the open carrier, see Figure 5 , so that the arrangement is arranged between the carrier outer wall 30 and the temperature sensor device 17 or the sensor carrier 18. The temperature sensor 19 is thus positioned directly adjacent to the flat, rail-shaped conductor 15.

[0036] Then cover Figure 6 3 to form a closed housing. The cover 31 has a plurality of latching elements 32, by means of which the cover is latched to the carrier 24. A wall section 33 is also provided, on which a spring element 34 in the form of a leaf spring 35 is arranged, which points to the middle of the cover. The leaf spring 35 serves to spring the temperature sensor device 17 or the sensor carrier 18 against the conductor 15 and thus the temperature sensor 19 against the conductor, as will be discussed below. In addition, a wall section 36 is provided, which is arranged adjacent to the wall section 33.

[0037] like Figure 7 As shown, the cover 31 is now placed on the carrier 24 as indicated by the arrow P2. In this case, the wall section 36 engages in the opening 28 and the wall section 33 engages in the opening 29. Figure 7 and Figure 8 As shown, the leaf spring 35 is directly adjacent to the temperature sensor device 17 , so that it spring-loads the conductor 15 and thus the temperature sensor 19 . The fixing takes place via the snap-on latching element 32 .

[0038] like Fig. 9 As shown, this results in a closed housing 37, wherein Fig. 9 Shown is a fully assembled temperature sensor arrangement 16. The housing 37 is almost completely closed, so that any disruptive influences do not reach the actual measuring range.

[0039] As per Fig.10 The cross-sectional view of FIG. 1 clearly shows that the temperature sensor device 17 or the sensor carrier 18 is firmly pressed against the conductor 15 via the leaf spring 35, and thus the temperature sensor 19 is also firmly pressed against the conductor via the leaf spring, as shown in FIG. Fig.10 As shown in FIG. 3 , a cover 31 can be cast to enable optimal thermal coupling for accurate measurement. In addition, the closed housing 37 also provides ideal protection.

[0040] As simple as assembly, in this case only the temperature sensor device 17 has to be attached to the carrier 24, after which the arrangement has to be fixed to the conductor 15 and now only the cover 31 has to be clipped on, so that disassembly for maintenance is also simple.

[0041] Description of Reference Numerals

[0042] 1 Electric machine 2 Stator 3 Winding 4 Conductor 5 Recess 6 Stator tooth 7 End 8 Interconnection ring 9 Connection section 10 Housing 11 Power source 12 Housing 13 Conductor rail 14 Connection terminal 15 Conductor 16 Temperature sensor arrangement 17 Temperature sensor device 18 Sensor carrier 19 Temperature sensor 20 Connection cable 21 Cable 22 Heat shrink tubing 23 Form-fit contour 24 Carrier 25 Cable holding section 26 Engagement contour section 27 Opening 28 Opening 29 Opening 30 Support wall 31 Cover 32 Locking element 33 Wall section 34 Spring element 35 Leaf spring 36 Wall section 37 Housing R Radial plane P1 Arrow P2 Arrow

Claims

1. An electric machine comprising a stator (2) having a winding (3) and at least one temperature sensor arrangement having a temperature sensor device (17) for detecting a temperature in the region of the winding, Features: The winding (3) comprises a first conductor (4), at least a portion of which has an end (7, 7a) protruding beyond the winding (3), A portion of the end portion (7, 7a) is connected to an axial or radial interconnection ring (8) arranged on the winding (3), the interconnection ring (8) comprising a second conductor (15), the temperature sensor arrangement (16) being arranged on the second conductor (15) and the temperature sensor device (17) being thermally coupled to the second conductor (15), The temperature sensor device (17) comprises a sensor carrier (18), on which a temperature sensor (19) is arranged, the sensor carrier (18) having a form-fitting contour coupled to a matching contour (26) on a carrier (24), so that the sensor carrier (18) is fixed relative to the carrier during coupling, wherein the form-fitting contour of the sensor carrier (18) has an undercut in a front end portion of the sensor carrier (18).

2. The motor according to claim 1, characterized in that The temperature sensor arrangement (16) has a housing (37) in which the temperature sensor (19) is received and through which the conductor (15) extends.

3. The motor according to claim 2, characterized in that The housing (37) has: the carrier (24) on which the temperature sensor device (17) is fixed; and a cover (31) which can be detachably fastened to the carrier (24) and closes the housing (37).

4. The motor according to claim 3, characterized in that The cover (31) is fastened to the carrier (24) via a latching connection or a clamping connection (32).

5. The motor according to claim 4, characterized in that A spring element (34) is provided for spring-loading the temperature sensor (19) against the conductor (15).

6. The motor according to claim 5, characterized in that The spring element (34) is arranged on the cover (31) and, when the cover (31) is mounted, is positioned laterally adjacent to the sensor carrier (18), the conductor (15) extending on the opposite side of the sensor carrier.

7. The motor according to claim 5 or 6, characterized in that: The spring element (34) is a curved leaf spring (35).

8. The electric machine according to claim 2, characterized in that The housing (37) is made of plastic.

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