DE102015006345A1 - Electric machine with temperature sensor - Google Patents

Abstract

The invention relates to an electric machine (1), preferably for driving a motor vehicle with a rotor, a stator (3) with concentrated wound individual poles and a temperature sensor (4) comprising a sensor tip (5) for sensing an operating temperature of the stator (3). wherein the sensor tip (5) of the temperature sensor (4) received and executable in a conical receptacle (10) of the stator (3) and introduced as a measuring range in an environment around at least one coil (6, 7) of the stator (3) is, wherein the temperature sensor (4) axially biased interchangeable in the receptacle (10) of the stator (3) is provided.

Description

The invention relates to an electrical machine with a temperature sensor. From the prior art electrical machines with temperature sensors are known. The built in the stator of the electric drive engine temperature sensor is used to determine the prevailing operating temperature. This is necessary for accurate control and protection against damage to the drive motor due to thermal overloads.

For the most accurate determination of the operating temperature plays in addition to the general geometric tolerances, the thermal connection of the temperature sensor to the stator a significant role.

One way of detecting the temperature of an electric drive machine is to accommodate a temperature-sensitive sensor within the stator winding. On the one hand, it is advantageous to detect the temperature at virtually any point within the stator. On the other hand, the interchangeability of such built-temperature sensors designed as extremely difficult.

Another possibility is to mount temperature sensors on freely accessible stator areas, such as end faces (see 1 ). For this purpose, suitable locations are provided on the stator and mounted temperature sensors, which are interchangeable due to their fastening means.

Due to the manufacturing tolerances arise between the temperature sensors and the stator different sized gaps. These reduce the thermal conductivity, which is due to the very good insulating ability of gases, in particular of air. However, this has a negative effect on a precise control of the drive machine, because the heating time of the temperature sensors significantly extended.

In the DE102012011004A1 a plurality of windings form a winding head and in the region of a winding a receiving space is formed by a placeholder is inserted between the wire coils before impregnation and thus solidifying the winding. After curing of the impregnating the placeholder is removed and in the receiving space a temperature sensor embedded in a tubular element is preferably inserted in the axial direction. In case of failure of the temperature sensor this can be easily replaced. Multiple windings forming an annular winding head arise in distributed windings which have a low power density due to axially long end windings and low Nutfüllfaktoren in axially short hybrid drives.

In a temperature sensor according to DE102011084229A1 a sensor element is attached to a fastening device by a connecting device, which is designed to be resilient in a longitudinal direction of the temperature sensor. The sensor connection lines can be designed such that they exert the resilient force on the sensor element, whereby the sensor connection lines can be any electrically conductive lines and depending on the force to be exerted on the sensor element a material with corresponding properties and dimensions is selected. Vibrations occurring in electric motors lead to micro movements between the sensor tip and the winding and can damage the thin insulation layer (wire enamel).

In order to be independent of tolerances, in DE10154920A1 a thermally conductive device is used which thermally connects a replaceable temperature sensor to the winding. The additional component increases the thermal time constant of the sensor system and the cost.

DE6972611T2 describes a winding temperature sensing element which is mounted through a through hole in the motor housing and pressed against the winding by a deflectable tab, wherein a highly thermally conductive resin provides good thermal conductivity between the sensing element and the motor winding.

An elastic arm of the housing of a thermal circuit breaker is similar in the DE4142180C1 Fluctuations of the winding head height and thus ensures a pressing of the contact surface against the winding.

It is therefore the technical task to improve a contact between a replaceable temperature sensor and stator with concentrated wound individual poles so that the lowest possible heat transfer coefficient and thus a faster response of the temperature sensor can be achieved.

The object is achieved in particular by an electric machine, preferably for driving a motor vehicle with a rotor, a stator with concentrated wound single poles and a temperature sensor having a sensor tip for sensing an operating temperature of the stator winding, wherein the sensor tip of the temperature sensor on and executable in one taken conically trained recording of the stator and as a measuring range in an environment around at least one coil of the stator can be introduced, wherein the temperature sensor axially biased interchangeable is provided in the receptacle of the stator.

By providing the conical receiving and an axial bias, a contact between the temperature sensor and stator can be improved so that the lowest possible heat transfer coefficient and thus a faster response of the temperature sensor can be achieved.

Preferably, an axial biasing force acting on the temperature sensor can be generated by means of a force-applying means.

Preferably, the sensor tip of the temperature sensor has a contour which can be inserted into the conically formed receptacle of the stator. Here, the conical receiving the stator is to be understood as a mating contour to the contour of the sensor tip of the temperature sensor. Preferably, the sensor tip is conical.

Preferably, the temperature sensor is a temperature-sensitive sensor. Particularly preferably, the temperature sensor is an electrical or electronic component that provides an electrical signal as a measure of the temperature.

The electric machine is preferably an electric motor.

In a further embodiment according to the invention, the sensor tip is designed to be inserted as far as possible into a region between two coils of the stator.

In this way, the temperature to be measured can be determined fairly accurately.

In a further embodiment according to the invention, shapes of the temperature sensor and the receptacle are matched to one another such that the sensor tip can penetrate into a region of the stator which ensures sufficient thermal conductivity for determining the operating temperature of the stator.

In this way, different sized gap dimensions can be avoided, which leads to an improvement of the thermal conductivity.

In a further embodiment according to the invention, the sensor tip can be brought directly into contact with a surface to be measured.

This allows the temperature to be determined in a simple way.

In a further embodiment according to the invention, the sensor tip and the stator have different material compliances.

In a further embodiment of the invention, the sensor tip is made of a softer material than the stator. In this way, it is possible that the sensor tip deformed so as to easily adapt to the mating contour of the recess. For a good heat-conducting contact can be achieved.

Alternatively, the stator is made of a softer material than the sensor tip. In this way, it is possible for portions of the stator to deform in order to easily adapt to the contour of the sensor tip. This is also a good heat-conducting contact can be achieved.

In a further embodiment according to the invention, the temperature sensor has a housing with a force-applying means or the temperature sensor is connected to the housing via the force-applying means.

Thus, two embodiments are possible to apply an axial preload on the temperature sensor.

In a further embodiment according to the invention, the force-applying means is arranged to press the temperature sensor in the direction of the turns.

In this way, by means of the force-applying means an axial preload can be generated, which preferably presses the temperature sensor in the direction of the turns in the recess.

In another embodiment of the invention, the force-applying means is a resilient element.

Preferably, the resilient element is designed as a helical spring. Preferably, the resilient element is made of plastic.

In another embodiment of the invention, the force-applying means is a flexible tab. Preferably, the flexible flap is made of plastic.

The invention will now be exemplified by figures. Examples of the invention to which this is not limited and from which further features of the invention may result are shown in the figures.

Show it:

1 a schematic section through an electrical machine,

2 a schematic section through an electrical machine according to the invention before the onset of a temperature sensor,

3 a schematic section through an electrical machine according to the invention with the temperature sensor 2 .

4 a schematic view of a temperature sensor,

5a a schematic view of an alternative temperature sensor,

5b the temperature sensor off 5a before and after an assembly,

6a a schematic view of another alternative temperature sensor,

6b the temperature sensor off 6a from a different perspective,

6c the temperature sensor off 6a when installed,

7a a schematic view of another alternative temperature sensor,

7b the temperature sensor off 7a from a different perspective, and

7c the temperature sensor off 7a in the installed state.

1 shows a schematic section through a portion of an electric machine.

The electric machine 2 has a rotor (not shown), a stator 3 and a replaceable temperature sensor 4 with a sensor tip 5 for sensing an operating temperature of the stator 3 on. The stator 3 has coils 6 . 7 on. The sensor tip 5 of the temperature sensor 4 is in an area in front of the coils 6 . 7 of the stator 3 brought in. A stator carrier 17 (not visible) closes the front side of the stator 3 at.

Electric lines 18 are at one of the sensor tip 5 opposite end on the temperature sensor 4 intended. Furthermore, a fastening 8th for mounting the temperature sensor 4 on the stator carrier 17 intended.

The temperature sensor 4 is in a receptacle of the stator 3 used. The receptacle has a cylindrical shape 20 on. Due to manufacturing tolerances arise between the temperature sensor 4 and the stator 3 different sized column 21 , These reduce the thermal conductivity, which is due to the very good insulating ability of gases - especially of air. This has a negative effect on accurate control of the machine 2 because of the heating time of the temperature sensor 4 significantly extended.

An improvement of the contact between temperature sensor 4 and stator 3 is ensured by an embodiment according to the following figures.

2 shows a schematic section through an electrical machine according to the invention before the onset of a temperature sensor.

The electric machine 1 is preferably for driving a motor vehicle with the under 1 provided components described.

In contrast to 1 is the sensor tip 5 of the temperature sensor 4 ein- and executable in a conical recording 10 of the stator 3 received. The sensor tip 5 is formed as far as possible in an area between the two coils 6 . 7 of the stator 3 to be introduced.

The shapes of temperature sensor 4 and recording 10 are coordinated so that the sensor tip 5 into a region of the stator 3 can penetrate, which has sufficient thermal conductivity to determine the operating temperature of the stator 3 guaranteed.

For this purpose, the sensor tip 5 of the temperature sensor 4 a contour on that in the conical recording 10 of the stator 3 is insertable. Here is the conical recording 10 of the stator 3 as a counter contour to the contour of the sensor tip 5 of the temperature sensor 4 to understand. This shows the sensor tip 5 a conical contour 11 on.

3 shows a schematic section through an electrical machine according to the invention with the temperature sensor 2 ,

The electric machine 1 points - the stator 3 and the temperature sensor 4 for sensing an operating temperature of the stator 3 on. The sensor tip 5 of the temperature sensor 4 is in the conically shaped recording 10 of the stator 3 added. The sensor tip 5 of the temperature sensor 4 is tangential between two adjacent coils 6 . 7 of the stator 3 introduced in such a way that it is heated by both coils. As is customary with concentrated wound coils, a conductor wire with a strong one is used Train wound directly around the pole, so that the coils form a solid non-deformable unit. The temperature sensor 4 is axially biased interchangeable in the receptacle 10 of the stator 3 provided.

An axial preload force 19 pointing to the temperature sensor 4 acts, can be by means of a kraftbeaufschlagenden agent, as in the 4 to 7c described, generate.

The sensor tip 5 is directly adjacent to a surface to be measured within the stator 3 brought into contact. This is where the sensor tip point 5 and the stator 3 different Materialnachbiebigkeiten on. To get the best possible contact between the sensor tip 5 of the temperature sensor 4 and the stator 3 To achieve a relatively hard sensor material and a relatively soft stator material is used. The different Materialnachbiebigkeiten place depending on the axial preload force 19 a good surface contact safely. Analog would be a relatively soft sensor material, compared to a relatively hard stator material conceivable. Relative always means the comparison between the relevant areas.

The sensor tip 5 gets into the conically shaped receptacle 10 of the stator 3 pressed in and under the axial biasing force 19 fixed. The attachment of the temperature sensor 4 allows compensation of the prevailing axial tolerances and a nearly constant axial preload force 19 ,

By providing the conical recording 10 and the axial preload force 19 , lets contact between temperature sensor 4 and stator 3 improve such that the lowest possible heat transfer coefficient and thus a faster response of the temperature sensor 4 is reachable.

4 shows a schematic view of a temperature sensor.

The temperature sensor 4 has a housing 12 on. The housing 12 has a mounting area 8th , a force-inducing agent 9 , an O-ring 13 for sealing, an opening 14 and a cable outlet 15 on. The force-inducing agent 9 is a flexible flap. The force-inducing agent 9 is with the attachment area 8th connected. The force-inducing agent 9 is set, the axial preload force 19 to generate and the temperature sensor 4 with the sensor tip 5 in the direction of the coils 6 . 7 of the stator 3 to squeeze. This creates the axial tolerance compensation.

5a shows a schematic view of an alternative temperature sensor.

The temperature sensor 4 has a housing 12 on. The housing 12 has a mounting area 8th or a force-inducing agent 9 , an O-ring 13 for sealing, an opening 14 (Slot) for attaching the temperature sensor 4 and a cable outlet 15 on. The force-inducing agent 9 is a flexible tab (spring tab). The force-inducing agent 9 is set, the axial preload force 19 to generate and the temperature sensor 4 with the sensor tip 5 in the direction of the coils 6 . 7 of the stator 3 to squeeze. This creates the axial tolerance compensation.

5b shows the temperature sensor 5a before and after an assembly.

Before mounting in the receptacle 10 of the stator 3 are the attachment area 8th or the imparting agent 9 in a starting position and are opposite the housing 12 slightly inclined. After mounting in the receptacle 10 of the stator 3 are the attachment area 8th or the imparting agent 9 in an end position and are flush with the housing on one side 12 ,

6a shows a schematic view of another alternative temperature sensor. 6b shows the temperature sensor 6a from a different perspective.

The temperature sensor 4 is about the imparting agent 9 with an external housing 12 connected. The housing 12 has a mounting area 8th , a force-inducing agent 9 , an O-ring 13 (not labeled) and an opening 14 for securing the housing 12 on. The force-inducing agent 9 is a springy element. The force-inducing agent 9 is set, the axial preload force 19 to generate and the temperature sensor 4 with the sensor tip 5 in the direction of the coils 6 . 7 of the stator 3 to squeeze. This creates the axial tolerance compensation.

6c shows the temperature sensor 6a in the installed state.

In 6c is the arrangement on the stator 3 with the coils on the right side in direct contact with the sensor tip 5 you can see. By means of a lanyard 16 , here a screw, can the housing 12 with the temperature sensor 4 on the stator carrier 17 (see. 3 ).

7a shows a schematic view of another alternative temperature sensor. 7b shows the temperature sensor 7a from a different perspective.

The temperature sensor 4 is via the force-applying means with an external housing 12 connected. The housing 12 has a mounting area 8th , a force-inducing agent 9 , an O-ring 13 (not labeled) and an opening 14 for securing the housing 12 on. The force-inducing agent 9 is a resilient element, namely a coil spring. The force-inducing agent 9 is set, the axial preload force 19 to generate and the temperature sensor 4 with the sensor tip 5 in the direction of the coils 6 . 7 of the stator 3 to squeeze. This creates the axial tolerance compensation.

Furthermore, the cable outlet runs 15 in an area by the force-applying agent 9 , The cable outlet 15 has in this area a bending radius, which as well as the kraftbeaufschlagende means 9 ensures axial tolerance compensation. Other spring elements are possible here.

7c shows the temperature sensor 7a in the installed state.

In 7c is the arrangement on the stator 3 with the coils on the right side in direct contact with the sensor tip 5 to see. By means of a lanyard 16 , here a screw, can the housing 12 with the temperature sensor 4 on the stator carrier 17 (see. 3 ).

LIST OF REFERENCE NUMBERS

1

electric machine

2

electrical machine of the prior art

3

stator

4

temperature sensor

5

sensor tip

6

Kitchen sink

7

Kitchen sink

8th

attachment

9

force-inducing agent

10

admission

11

conical shape

12

casing

13

O-ring

14

opening

15

cable outlet

16

connecting means

17

stator

18

electrical connections

19

Biasing force / prestress

20

cylindrical shape

21

gap

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 102012011004 A1 [0006]
• DE 102011084229 A1 [0007]
• DE 10154920 A1 [0008]
• DE 6972611 T2 [0009]
• DE 4142180 C1 [0010]

Claims (10)

Electric machine ( 1 ), preferably for driving a motor vehicle with a rotor, a stator ( 3 ) with concentrated wound poles and a temperature sensor ( 4 ) having a sensor tip ( 5 ) for sensing an operating temperature of the stator ( 3 ), whereby the sensor tip ( 5 ) of the temperature sensor ( 4 ) ein¬ and executable in a conical recording ( 10 ) of the stator ( 3 ) and as a measuring range in an environment around at least one coil ( 6 . 7 ) of the stator ( 3 ), wherein the temperature sensor ( 4 ) axially biased interchangeable in the receptacle ( 10 ) of the stator ( 3 ). Electric machine ( 1 ) according to claim 1, wherein the sensor tip ( 5 ) is formed as far as possible into an area between two coils ( 6 . 7 ) of the stator ( 3 ) to be introduced. Electric machine of the stator ( 1 ) according to one of claims 1 and 2, wherein shapes of temperature sensor ( 4 ) and recording ( 10 ) are coordinated so that the sensor tip ( 5 ) in a region of the stator ( 3 ), which has sufficient thermal conductivity to determine the operating temperature of the stator ( 3 ) guaranteed. Electric machine ( 1 ) according to one of the preceding claims, wherein the sensor tip ( 5 ) directly to a surface to be measured within the stator ( 3 ) is brought into contact. Electric machine ( 1 ) according to one of the preceding claims, wherein the sensor tip ( 5 ) and the stator ( 3 ) have different Materialnachgiebigkeiten. Electric machine ( 1 ) according to claim 5, wherein the sensor tip ( 5 ) of a softer material than the stator ( 3 ) consists. Electric machine ( 1 ) according to one of the preceding claims, wherein the temperature sensor ( 4 ) a housing ( 12 ) with a force-inducing agent ( 9 ) or the temperature sensor ( 4 ) on the impulse-causing agent ( 9 ) with the housing ( 12 ) connected is. Electric machine ( 1 ) according to claim 7, wherein the force-applying means ( 9 ), the temperature sensor ( 4 ) in the direction of the coils ( 6 . 7 ) to press. Electric machine ( 1 ) according to one of claims 7 to 8, wherein the force-applying means ( 9 ) is a resilient element. Electric machine ( 1 ) according to one of claims 7 to 8, wherein the force-applying means ( 9 ) is a flexible tab.

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