Inductive position sensor including an open receiving device

Abstract

The invention relates to an inductive position sensor (1a) comprising a substrate (2) on which are arranged a transmitting element (3a, 3b, 3c) for emitting an oscillating magnetic field towards a target to generate a modified oscillating magnetic field, and a receiving device (5) for detecting the oscillating magnetic field and transmitting it to a signal processing unit (6) to determine the angular position of the target. The transmitting element defines a first internal zone (10) and the receiving device defines a second internal zone (11). The receiving device comprises a first opening (13) and has a crescent shape. The signal processing unit is located in the second internal zone of the receiving device, extending into the first opening, or positioned opposite the second internal zone, extending into an opening (16) opposite the first opening. Abstract figure: Fig. 1

Description

Title of the invention: Inductive position sensor comprising an open receiving device

[0001] The invention relates to the field of position sensors. It relates more particularly to the field of position sensors which are configured to detect the angular position of a rotating target inductively.

[0002] Inductive position sensors, known as eddy current sensors, use a magnetic field to determine the angular position of the rotating target which forms a coupling element.

[0003] These position sensors are notably used in electric motors of electric or hybrid vehicles comprising a rotor rotating relative to a stator.

[0004] The angular position of the rotor is determined relative to the stator. The target is mounted at the end of a rotor shaft to modify a magnetic field transmitted by a transmitter. The target is centered relative to an axis of rotation of the rotor. The target comprises a plurality of blades that provide a repetitive and periodic magnetic field pattern relative to the axis of rotation of the rotor.

[0005] The position sensor is mounted fixed relative to the rotor, opposite the target and the end of the rotor shaft. The position sensor comprises a substrate (or printed circuit) comprising at least one emission element intended to emit an oscillating magnetic field towards the target, generating a modified oscillating magnetic field at a given frequency.

[0006] The substrate comprises a receiving device for detecting the modified oscillating magnetic field and transmitting it to a signal processing unit provided on the substrate to deduce the angular position of the target.

[0007] The transmitting element has a circular shape and is centered around a transmitting axis. The receiving device also has a circular shape and is centered around a receiving axis. The receiving device is concentric with the transmitting element. The receiving device therefore has a smaller diameter than that of the transmitting element.

[0008] The emission axis of the emission element and the reception axis of the reception device are aligned with the rotation axis of the target which is itself aligned with the rotation axis of the rotor.

[0009] Conventionally, the signal processing unit is integrated on the substrate and positioned outside the transmission device and the reception element, on the periphery of the latter.

[0010] However, these inductive position sensors are bulky and therefore more difficult to be integrated into rotating electrical machines.

[0011] The aim of the invention is therefore to overcome the drawbacks of the prior art by proposing an inductive position sensor that is more compact and easier to integrate into a rotating electrical machine.

[0012] To this end, the invention thus relates, in its broadest sense, to an inductive position sensor for a rotating electrical machine comprising a substrate on which are arranged at least one transmitting element intended to transmit an oscillating magnetic field towards a rotating target to generate a modified oscillating magnetic field. The substrate comprises a receiving device intended to detect the modified oscillating magnetic field and to transmit it to a signal processing unit to determine the angular position of the target. The transmitting element surrounds the receiving device. The transmitting element delimits a first internal zone and the receiving device delimits a second internal zone.

[0013] According to the invention, the receiving device comprises a first opening so as to have a crescent shape. The signal processing unit is positioned in the second internal zone of the receiving device extending to the inside of the first opening or is positioned opposite the second internal zone extending to an opening zone positioned opposite the first opening.

[0014] The invention thus provides an inductive position sensor in the form of an electronic card that is more compact and easier to integrate into a rotating electrical machine.

[0015] According to a variant, the inductive position sensor comprises N angular periods. The receiving device covers a first angular zone of at least 3607N. The first opening of the receiving device covers a second angular zone corresponding to at least one angular period.

[0016] According to another variant, the emission element has a circular shape.

[0017] According to another variant, the receiving device is positioned inside the first internal area of ​​the transmitting element. The substrate comprises a first substrate layer on which the transmitting element and the receiving device are integrated. The substrate comprises a second substrate layer on which the signal processing unit is integrated. The first and second substrate layers are superimposed. The signal processing unit is positioned opposite the second internal area of ​​the receiving device and extends into the opening area.

[0018] According to another variant, the receiving device is positioned opposite the first internal zone of the emission element. The substrate comprises a first substrate layer on which the emission element is integrated and a second substrate layer on which the receiving device and the signal processing unit are integrated. The first and second substrate layers are superimposed. The signal processing unit is positioned inside the second internal area of ​​the receiving device and extends into the first opening.

[0019] According to another variant, the receiving device is positioned opposite the first internal zone of the transmitting element. The substrate comprises a first substrate layer on which the transmitting element is integrated, a second substrate layer on which the receiving device is integrated and a third layer on which the signal processing unit is integrated. The first, second and third substrate layers are superimposed. The signal processing unit is positioned opposite the second internal zone of the receiving device and extends to the inside of the opening zone.

[0020] According to another variant, the receiving device comprises an external border surrounded by the emitting element. The emitting element comprises a second opening merged with the first opening of the receiving device so as to have a crescent shape.

[0021] According to another variant, the signal processing unit is positioned in the first internal zone of the transmission element and passes through the second opening.

[0022] According to another variant, the signal processing unit is positioned opposite the first internal zone of the emission element and extends to the opening zone.

[0023] The invention also relates to a rotating electrical machine for a vehicle comprising a stator and a rotor mounted to rotate relative to the stator.

[0024] The rotating electrical machine comprises an inductive position sensor as defined previously and a target positioned on the rotor, opposite the inductive position sensor.

[0025] Embodiments of the present invention will be described below, by way of non-limiting examples, with reference to the appended figures in which:

[0026] [Fig.l] schematically illustrates an inductive position sensor, according to one embodiment of the invention;

[0027] [Fig.2] schematically illustrates an inductive position sensor, according to another mode of carrying out the invention.

[0028] The invention relates to an inductive position sensor 1a, 1b, as illustrated in Figures 1 and 2.

[0029] The inductive position sensor 1a, 1b uses a magnetic field to determine the angular position of a rotating target which is used as a coupling element.

[0030] The inductive position sensor 1a, 1b and the target are intended to be mounted in a rotating electrical machine such as an electric motor of an electric or hybrid vehicle. comprising a rotor rotating relative to a stator.

[0031] The angular position of the rotor is determined relative to the stator. The target is mounted on one end of a rotor shaft to modify a magnetic field emitted by a transmitter. The target includes an axis of rotation that is aligned with an axis of rotation of the rotor. The target includes a plurality of blades that provide a repetitive and periodic magnetic field pattern relative to the axis of rotation of the rotor.

[0032] The inductive position sensor 1a, 1b comprises a substrate 2 (or printed circuit) on which are arranged three emission elements 3a, 3b, 3c intended to each emit an oscillating magnetic field towards the target, generating a modified oscillating magnetic field at a given frequency.

[0033] The inductive position sensor 1a, 1b comprises a receiving device 5 for detecting the modified oscillating magnetic field and transmitting it to a signal processing unit 6 provided on the substrate 2 to measure the angular position of the target. The modified oscillating magnetic field generates an electromotive force at a given frequency in the receiving device 5. This electromotive force is processed by the signal processing unit 6 so as to provide output signals for measuring the position of the target.

[0034] The inductive position sensor 1a, 1b is mounted fixed relative to the rotor. The transmitting elements 3a, 3b, 3c and the receiving device 5 of the inductive position sensor 1a, 1b are positioned opposite the target and therefore opposite the end of the rotor shaft. In other words, the inductive position sensor 1a, 1b is therefore positioned axially relative to the axis of rotation of the rotor.

[0035] The receiving device 5 comprises several transmission antennas 8a, 8b, 8c. In the examples of FIGS. 1 and 2, the receiving device 5 comprises three transmission antennas 8a, 8b, 8c.

[0036] Traditionally, the number of transmission antennas 8a, 8b, 8c is proportional to the number of blades (or angular sectors) of the target. The target therefore comprises three angular sectors. It may comprise six, if the reception device 5 comprises six transmission antennas 8a, 8b, 8c, for example. The inductive position sensor 1a, 1b then comprises two signal processing units 6.

[0037] In the embodiment of [Fig.l], the three emitting elements 3a, 3b, 3c have a symmetry of revolution. The three emitting elements 3a, 3b, 3c have a circular shape, and are centered around a common central axis.

[0038] The three emission elements 3a, 3b, 3c are positioned concentrically with respect to each other. A first emission element 3a is positioned inside a second emission element 3b having a larger diameter than that of the first emission element 3a. A third emission element 3c, having a larger diameter than that of the second emission element 3b, surrounds the second emission element 3b.

[0039] The emitting elements 3a, 3b, 3c emit oscillating magnetic fields at frequencies distinct from each other. Three different frequencies are therefore emitted towards the target.

[0040] Alternatively, the inductive position sensor 1a, 1b may comprise a single transmitting element 3a, 3b, 3c or two transmitting elements 3a, 3b, 3c or more than three transmitting elements 3a, 3b, 3c.

[0041] The inductive position sensor 1a, 1b is in the form of an electronic card which is supported by a bracket and which can be protected by a cover.

[0042] The emission element(s) 3a, 3b, 3c delimit a first circular internal zone 10. The reception device 5 delimits a second circular internal zone 11.

[0043] According to the invention, the receiving device 5 has a quasi-annular general shape and comprises a first opening 13. The receiving device 5 has a crescent shape, i.e. a general C shape.

[0044] The signal processing unit 6 is either positioned in the second internal zone 11 of the reception device 5 by extending into the first opening 13 or positioned opposite the second internal zone 11 by extending into an opening zone 16 located opposite the first opening 13, that is to say above or below the first opening 13, so as not to be superimposed on the reception device 5 in the direction of the central axis.

[0045] The receiving device 5 is also centered relative to the central axis.

[0046] According to the embodiment shown in [Fig.l], the three emission elements 3a, 3b, 3c have a circular shape. The signal processing unit 6 is positioned either inside the first internal zone 10 of the emission elements 3a, 3b, 3c or opposite the first internal zone 10, i.e. above or below it.

[0047] When the receiving device 5 is positioned inside the first internal zone 10 of the emission elements 3a, 3b, 3c, the substrate 2 comprises a first substrate layer on which the emission elements 3a, 3b, 3c and the receiving device 5 are integrated. The emission elements 3a, 3b, 3c and the receiving device 5 are positioned in the same plane. The first and second internal zones 10, 11 are then merged.

[0048] The substrate 2 also comprises a second substrate layer on which the signal processing unit 6 is integrated. The first and second substrate layers are superimposed.

[0049] The signal processing unit 6 is positioned opposite the second internal zone 11 of the receiving device 5 and extends to the opening zone 16 which is positioned opposite the first opening 13.

[0050] The signal processing unit 6 is also positioned opposite the first internal zone 10 of the emission elements 3a, 3b, 3c and extends to an area positioned above or below a portion 15 of the emission elements 3a, 3b, 3c.

[0051] In the example of [Fig. 1], the signal processing unit 6 comprises an extended portion 4 which extends beyond the first opening 13 or the area located above the first opening 13, so that the signal processing unit 6 extends above the transmission elements 3a, 3b, 3c to an area 17 external to the transmission elements 3a, 3b, 3c.

[0052] Alternatively, the signal processing unit 6 does not comprise an extended portion 4 which extends beyond the first opening 13 or the area 16 located above the first opening 13. The signal processing unit 6 extends only as far as the first opening 13 or the opening area 16.

[0053] According to another variant, the reception device 5 is positioned opposite the first internal zone 10 of the emission elements 3a, 3b, 3c. The substrate 2 comprises a first substrate layer on which the emission elements 3a, 3b, 3c are integrated and a second substrate layer on which the reception device 5 and the signal processing unit 6 are integrated. The first and second substrate layers are superimposed.

[0054] The signal processing unit 6 is positioned inside the second internal zone 11 of the receiving device 5 and extends into the first opening 13. The signal processing unit 6 may extend beyond the first opening 13, to the external zone 17.

[0055] According to another variant, the reception device 5 is positioned opposite the first internal zone 10 of the emission elements 3a, 3b, 3c. The substrate 2 comprises a first substrate layer on which the emission elements 3a, 3b, 3c are integrated, a second substrate layer on which the reception device 5 is integrated and a third layer on which the signal processing unit 6 is integrated. The first, second and third substrate layers are superimposed.

[0056] The signal processing unit 6 is positioned opposite the second internal zone 11 of the reception device 5 and extends above the first opening 13, i.e. up to the opening zone 16. The signal processing unit 6 is also positioned opposite the first internal zone 10 of the transmission elements 3a, 3b, 3c.

[0057] As illustrated in [Fig.l], the substrate 2 comprises several orifices 7 passing through the interior of the emission elements 3a, 3b, 3c and the interior of the reception device 5. In other words, the orifices 7 pass through the first internal zone 10 of the emission elements 3a, 3b, 3c and the second internal zone 11 of the reception device 5. The signal processing unit 6 is connected to connection elements provided on a connector positioned outside the transmission elements 3a, 3b, 3c by electrical connections (not shown) each passing through one of the orifices 7.

[0058] In the example of [Fig.l], the substrate 2 comprises six orifices 7.

[0059] The electrical connections may be electrical wires or metal tracks etched on one of the substrate layers.

[0060] According to another embodiment illustrated in [Fig.2], the inductive position sensor 1b also comprises a receiving device 5 having a crescent shape with an external edge 12.

[0061] Unlike the first embodiment, the three emission elements 3a, 3b, 3c each have a crescent shape, i.e. a general C shape so as to form a second opening 14.

[0062] A first emission element 3a is positioned inside a second emission element 3b having a perimeter larger than that of the first emission element 3a. A third emission element 3c, having a perimeter larger than that of the second emission element 3b, surrounds the second emission element 3b.

[0063] The emission elements 3a, 3b, 3c surround the reception device 5 and more precisely the external edge 12 of the reception device 5 so that the second opening 14 coincides with the first opening 13 of the reception device 5.

[0064] According to a variant, the signal processing unit 6 is positioned in the first internal zone 10 of the transmission elements 3a, 3b, 3c and passes through the second opening 14.

[0065] The substrate 2 comprises a common substrate layer on which the transmitting elements 3a, 3b, 3c, the receiving device 5 and the signal processing unit 6 are integrated. The signal processing unit 6 is positioned inside the first and second internal zones 10, 11 and extends to at least the inside of the first and second openings 13, 14.

[0066] The signal processing unit 6 may have an extended portion 4 which extends beyond the first and second openings 13, 14.

[0067] According to another variant, the signal processing unit 6 is positioned opposite the first internal zone 10 of the emission elements 3a, 3b, 3c and extends above or below the second opening 14, that is to say up to the inside of the opening zone 16.

[0068] The substrate 2 then comprises a first substrate layer on which at least the emission elements 3a, 3b, 3c are integrated and a second substrate layer on which the signal processing unit 6 is integrated. The first and second substrate layers are superimposed. The signal processing unit 6 is positioned opposite the first internal zone 10 of the receiving device 5 and extends at least above the second opening 14.

[0069] Alternatively, the receiving device 5 can be positioned above or below the transmitting elements 3a, 3b, 3c but in such a way as not to be superimposed on the latter along the central axis.

[0070] The first opening 13 of the receiving device 5 is then positioned above or below the second opening 14 of the transmitting elements 3a, 3b, 3c.

[0071] The signal processing unit 6 can be positioned in the second internal zone 11 of the receiving device 5 by extending to the inside of the first opening 13 or positioned opposite the second internal zone 11 by extending to the opening zone 16, above or below the first opening 13.

[0072] Alternatively, the signal processing unit 6 may be positioned in the first internal zone 10 of the emission elements 3a, 3b, 3c and extend to the second opening 14 or beyond it.

[0073] Alternatively, the signal processing unit 6 may be positioned opposite the first internal zone 10 of the transmission elements 3a, 3b, 3c and the second internal zone 11 of the reception device 5. The signal processing unit 6 extends to the opening zone 16 or beyond it.

[0074] Whatever the embodiment, the transmission elements 3a, 3b, 3c are electrically connected to the signal processing unit 6 by connecting elements (not shown).

[0075] The substrate 2 also comprises several orifices as described previously. The signal processing unit 6 is connected to connection elements provided on a connector outside the emission elements 3a, 3b, 3c by electrical connections (not shown) each passing through one of the orifices.

[0076] Alternatively and whatever the embodiment, the substrate 2 may comprise two signal processing units 6 positioned next to each other or superimposed on two different substrate layers.

[0077] The signal processing unit 6 can be positioned opposite the target and therefore as close as possible to it.

[0078] Preferably, the signal processing unit 6 is positioned on the substrate layer furthest from the target.

[0079] Whatever the embodiment, the inductive position sensor 1a, 1b comprises N angular periods. The receiving device 5 covers a first angular zone of at least 360° / N and the first opening 13 of the receiving device 5 covers a second angular zone corresponding to at least one angular period.

[0080] The area covered by the receiving device 5 is therefore at least 360° / N without representing a complete revolution. There is therefore at least one unused angular period for make way for signal processing unit 6.

[0081] For example, for an inductive position sensor 1a, 1b comprising three angular periods, the area covered by the receiving device 5 is at least 120°. The opening 13 then extends over a portion of 240° maximum to accommodate the signal processing unit 6.

[0082] According to another example, if the inductive position sensor 1a, 1b has four angular periods, the opening 13 extends over a period corresponding to an angular sector of 90° maximum to place the signal processing unit 6 there.

[0083] According to a variant, the inductive position sensor 1a, 1b comprises two receiving devices 5 and three angular sectors. The receiving devices 5 each comprise an opening corresponding to a period, i.e. a free angular sector of 120° maximum for placing the signal processing unit 6 there.

[0084] Similarly, according to the embodiment of [Fig.2], the area covered by the emission elements 3a, 3b, 3c is therefore at least 360° / N without representing a complete revolution. There is therefore at least one unused angular period to leave room for the signal processing unit 6.

[0085] The preceding examples also apply to the crescent-shaped emission elements 3a, 3b, 3c.

Claims

Claims

1. Inductive position sensor (1a, 1b) for a rotating electrical machine comprising a substrate (2) on which are arranged at least one transmitting element (3a, 3b, 3c) intended to transmit an oscillating magnetic field towards a rotating target to generate a modified oscillating magnetic field, the substrate (2) comprising a receiving device (5) intended to detect the modified oscillating magnetic field and to transmit it to a signal processing unit (6) to determine the angular position of the target, the transmitting element (3a, 3b, 3c) surrounding the receiving device (5), the transmitting element (3a, 3b, 3c) delimiting a first internal zone (10) and the receiving device (5) delimiting a second internal zone (11), characterized in that the receiving device (5) comprises a first opening (13) so as to have a crescent shape,the signal processing unit (6) being positioned in the second internal zone (11) of the receiving device (5) extending to the inside of the first opening (13) or being positioned opposite the second internal zone (11) extending to an opening zone (16) positioned opposite the first opening (13), the sensor comprising N angular periods, the receiving device (5) covering a first angular zone of at least 360° / N, the first opening (13) of the receiving device (5) covering a second angular zone corresponding to at least one angular period..,

2. Inductive position sensor (1a, 1b) according to claim 1, characterized in that the transmitting element (3a, 3b, 3c) has a circular shape.

3. Inductive position sensor (1a, 1b) according to claim 1 or 2, characterized in that the receiving device (5) is positioned inside the first internal zone (10) of the transmitting element (3a, 3b, 3c), the substrate (2) comprising a first substrate layer on which the transmitting element (3a, 3b, 3c) and the receiving device (5) are integrated, the substrate (2) comprising a second substrate layer on which the signal processing unit (6) is integrated, the first and second substrate layers being superimposed, the signal processing unit (6) being positioned opposite the second internal zone (11) of the receiving device (5) and extending to the inside of the opening zone (16).

4. Inductive position sensor (1a, 1b) according to claim 2, characterized in that the receiving device (5) is positioned opposite the first internal zone (10) of the transmitting element (3a, 3b, 3c), the substrate (2) comprising a first substrate layer on which the transmitting element (3a, 3b, 3c) is integrated and a second substrate layer on which the receiving device (5) and the signal processing unit (6) are integrated, the first and second substrate layers being superimposed, the signal processing unit (6) being positioned inside the second internal zone (11) of the receiving device (5) and extending into the first opening (13).

5. Inductive position sensor (1a, 1b) according to claim 2, characterized in that the receiving device (5) is positioned opposite the first internal zone (10) of the transmitting element (3a, 3b, 3c), the substrate (2) comprising a first substrate layer on which the transmitting element (3a, 3b, 3c) is integrated, a second substrate layer on which the receiving device (5) is integrated and a third layer on which the signal processing unit (6) is integrated, the first, second and third substrate layers being superimposed, the signal processing unit (6) being positioned opposite the second internal zone (11) of the receiving device (5) and extending to the inside of the opening zone (16).

6. Inductive position sensor (1a, 1b) according to claim 1, characterized in that the receiving device (5) comprises an external border (12) surrounded by the transmitting element (3a, 3b, 3c), the transmitting element (3a, 3b, 3c) comprising a second opening (14) merged with the first opening (13) of the receiving device (5) so as to have a crescent shape.

7. Inductive position sensor (1a, 1b) according to claim 6, characterized in that the signal processing unit (6) is positioned in the first internal zone (10) of the transmitting element (3a, 3b, 3c) and passes through the second opening (14).

8. Inductive position sensor (1a, 1b) according to claim 6, characterized in that the signal processing unit (6) is positioned opposite the first internal zone (10) of the emission element (3a, 3b, 3c) and extends to the opening zone (16).

9. Rotating electric vehicle machine comprising a stator and a rotor mounted to rotate relative to the stator, characterized in that it comprises an inductive position sensor (1a, 1b) as defined according to any one of claims 1 to 8, and a target positioned on the rotor, opposite the inductive position sensor (1a, 1b).

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