ELECTRIC MACHINE HAVING INTEGRATED INDUCTIVE POSITION SENSOR WITH NON-CONTACT POWER TRANSFER
An electric machine includes a rotor assembly having a rotor shaft disposed along a central axis. The electric machine includes an inductive position sensor having a sensor target that is operatively connected to the rotor shaft. The sensor target is fixed relative to the rotor shaft such that the sensor target rotates with the rotor shaft. The electric machine includes a stationary member and a rotating member operatively connected to the rotor shaft. The rotating member is spaced from the stationary member by an air gap. The stationary member and the rotating member are configured to enable non-contact power transfer from the stationary member to the rotating member through the air gap. The non-contact power transfer may be an inductive power transfer or a capacitive power.
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The disclosure relates to an electric machine having an integrated inductive position sensor with non-contact power transfer. An electric machine generally includes a stator having a plurality of stator windings and a rotor rotatable within the stator. In a generator mode, the rotation of the rotor induces voltage in the stator winding, which powers an external load. Alternately, if an electric current is passed through the stator windings, the energized windings cause the rotor to rotate, and the machine will perform as a motor. Separately excited electric machines generally employ a resolver to determine the position and speed of the rotor. Furthermore, an external device is generally required to transfer power to the rotor in a separately excited electric machine. Accommodating a resolver and an external power transfer device in an electric machine is a challenging issue.
SUMMARYDisclosed herein is an electric machine having a rotor assembly with a rotor shaft disposed along a central axis. The electric machine includes an inductive position sensor having a sensor target that is operatively connected to the rotor shaft. The sensor target is fixed relative to the rotor shaft such that the sensor target rotates with the rotor shaft. The electric machine includes a stationary member and a rotating member operatively connected to the rotor shaft. The rotating member is spaced from the stationary member by an air gap. The stationary member and the rotating member are configured to enable non-contact power transfer from the stationary member to the rotating member through the air gap.
The inductive position sensor may include an inductive sensor board adapted to detect motion of the sensor target. The inductive sensor board is stationary. The inductive sensor board includes a plurality of windings having transmitting coils and receiving coils. The receiving coils may include a positive first coil, a negative first coil, a positive second coil, and a negative second coil. The electric machine may include a rectifier circuit directly connected to the rotating member. The rotor assembly includes rotor windings electrically coupled with the rectifier circuit.
In one embodiment, the stationary member includes a stationary core embedded with a first set of coils, the rotating member including a rotating core embedded with a second set of coils, and the non-contact power transfer between the stationary member and the rotating member is an inductive power transfer. Here, the sensor target may be positioned directly on the rotor shaft along the central axis. Alternatively, the sensor target may be positioned circumferentially around the rotor shaft. In another example, the sensor target may be positioned circumferentially around the rotating core, the rotating core is positioned circumferentially around the rotor shaft, and the sensor target is etched on the rotating core.
In another embodiment, the stationary member and the rotating member respectively include a stationary plate and a rotating plate positioned sufficiently close together to form a capacitor, such that the non-contact power transfer between the stationary member and the rotating member is a capacitive power transfer. Here, the sensor target may be positioned directly on the rotor shaft along the central axis. Alternatively, the sensor target may be positioned circumferentially around the rotor shaft. In some embodiments, the sensor target is positioned circumferentially around the rotating plate, the rotating plate is positioned circumferentially around the rotor shaft, and the sensor target is etched on the rotating plate.
Disclosed herein is a vehicle having an electric machine with a rotor assembly having a rotor shaft disposed along a central axis. An inductive position sensor having a sensor target is operatively connected to the rotor shaft and an inductive sensor board adapted to detect motion of the sensor target. The sensor target is fixed relative to the rotor shaft such that the sensor target rotates with the rotor shaft. A stationary member is operatively connected to the rotor shaft, the stationary member including a stationary core embedded with a first set of coils. A rotating member is operatively connected to the rotor shaft, the rotating member being spaced from the stationary member by an air gap, the rotating member including a rotating core embedded with a second set of coils. The inductive sensor board is stationary and includes a plurality of windings having transmitting coils and receiving coils. The stationary member and the rotating member are configured to enable non-contact power transfer from the stationary member to the rotating member through the air gap.
The above features and advantages and other features and advantages of the present disclosure are readily apparent from the following detailed description of the best modes for carrying out the disclosure when taken in connection with the accompanying drawings.
Representative embodiments of this disclosure are shown by way of non-limiting example in the drawings and are described in additional detail below. It should be understood, however, that the novel aspects of this disclosure are not limited to the particular forms illustrated in the above-enumerated drawings. Rather, the disclosure is to cover modifications, equivalents, combinations, sub-combinations, permutations, groupings, and alternatives falling within the scope of this disclosure as encompassed, for instance, by the appended claims.
DETAILED DESCRIPTIONReferring to the drawings, wherein like reference numbers refer to like components,
Electric machines generally employ a resolver to determine the rotational position and speed of the rotor relative to the stator. Furthermore, an external device is generally required for transferring power to the rotor in a separately excited electric machine. Accommodating both in an electric machine is a challenging issue. Referring to
Various embodiments of the electric machine 10 are shown in and described below with respect to
Referring to
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An example inductive position sensor 40 employable in the electric machine 10 of
Referring to
The sensor target 42 and the inductive sensor board 44 are integrated into the electric machine 10. The sensor target 42 is made of a conductive material in each of the embodiments described herein. For example, the sensor target 42 may be made of a ferrous material, such as steel. The sensor target 42 may be made of a non-ferrous material, such as aluminum and copper. In the example shown in
The inductive position sensor 40 relies on the change of induced voltage in the receiving coils 62 to determine the position of the sensor target 42, and thus the rotor shaft 14. Eddy currents flow in the target sensor 42 due to the high frequency signal in the transmitting coils 60. This results in the creation of an opposing magnetic field is created in the receiving coils 62. The net induced voltage changes in the receiving coils 62 is based on the location of the sensor target 42.
The microcircuit 48 of
Referring now to
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In the first embodiment of
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In the second embodiment, the stationary member 220 includes a stationary core 222 embedded with a first set of coils 224. The stationary member 220 may be supported or retained in position by one or more supporting structures, such as a first mount 226 from the drive unit housing. Referring to
Referring to
The second embodiment of
The stationary member 220 and the rotating member 230 are configured to enable non-contact power transfer from the stationary member 220 to the rotating member 230 through the air gap G. Similar to the first embodiment, the non-contact power transfer between the stationary member 220 and the rotating member 230 in the second embodiment is an inductive power transfer. Alternating current (AC) flowing through the stationary member 220 (first set of coils 224 embedded in the stationary core 222) results in the generation of a magnetic field that moves across the gap G to the rotating member 230 (second set of coils 234 embedded in the rotating core 232). The magnetic field results in an alternating current in the second set of coils 234, which is converted from AC to direct current (DC) by a rectifier circuit 250. The rectifier circuit 250 may be electrically coupled to the rotor windings 204 via connectors 252.
Referring now to
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Similar to the first and second embodiments, the rotating member 330 includes a rectifier circuit 350 for converting alternating current voltage to direct current voltage. The rectifier circuit 350 may be electrically coupled to the rotor windings 304 via connectors 352.
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In the fourth embodiment of
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Alternating current (AC) may be transmitted to the stationary member 420 through one or more inverters 24 in the vehicle 20, which convert direct current provided by an energy source 22 (see
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The fifth embodiment of
Similar to the fourth embodiment, the rotating member 530 in the fifth embodiment includes a rectifier circuit 550 for converting alternating current voltage to direct current voltage. The rectifier circuit 550 may be electrically coupled to the rotor windings 504 via connectors 552.
Referring now to
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In the sixth embodiment, the inductive position sensor 640 has a radial arrangement. Here, the sensor target 642 is positioned circumferentially around the rotating member 630. In other words, the sensor target 642 is radially external relative to the rotor shaft 614, the rotating plate 635 and the rectifier circuit 650. In some embodiments, the sensor target 642 may be etched on an exterior surface of the rotating plate 635. In the example shown in
In summary, various embodiments of an electric machine having an integrated inductive position sensor with non-contact power transfer are disclosed. The technical advantage here is that efficiency and packaging of an inductive sensor in a non-contact power transfer apparatus is optimized.
The controller C of
Look-up tables, databases, data repositories or other data stores described herein may include various kinds of mechanisms for storing, accessing, and retrieving various kinds of data, including a hierarchical database, a set of files in a file storage system, an application database in a proprietary format, a relational database management system (RDBMS), etc. Each such data store may be included within a computing device employing a computer operating system such as one of those mentioned above and may be accessed via a network in one or more of a variety of manners. A file system may be accessible from a computer operating system and may include files stored in various formats. An RDBMS may employ the Structured Query Language (SQL) in addition to a language for creating, storing, editing, and executing stored procedures, such as the PL/SQL language mentioned above.
The numerical values of parameters (e.g., of quantities or conditions) in this specification, including the appended claims, are to be understood as being modified in each respective instance by the term “about” whether or not “about” actually appears before the numerical value. “About” indicates that the stated numerical value allows some slight imprecision (with some approach to exactness in the value; about or reasonably close to the value; nearly). If the imprecision provided by “about” is not otherwise understood in the art with this ordinary meaning, then “about” as used herein indicates at least variations that may arise from ordinary methods of measuring and using such parameters. In addition, disclosure of ranges includes disclosure of each value and further divided ranges within the entire range. Each value within a range and the endpoints of a range are hereby disclosed as separate embodiments.
The detailed description and the drawings or FIGS. are supportive and descriptive of the disclosure, but the scope of the disclosure is defined solely by the claims. While some of the best modes and other embodiments for carrying out the claimed disclosure have been described in detail, various alternative designs and embodiments exist for practicing the disclosure defined in the appended claims. Furthermore, the embodiments shown in the drawings, or the characteristics of various embodiments mentioned in the present description, are not necessarily to be understood as embodiments independent of each other. Rather, it is possible that each of the characteristics described in one of the examples of an embodiment can be combined with one or a plurality of other desired characteristics from other embodiments, resulting in other embodiments not described in words or by reference to the drawings. Accordingly, such other embodiments fall within the framework of the scope of the appended claims.
Claims
1. An electric machine comprising:
- a rotor assembly having a rotor shaft disposed along a central axis;
- an inductive position sensor having a sensor target operatively connected to the rotor shaft, the sensor target being fixed relative to the rotor shaft such that the sensor target rotates with the rotor shaft;
- a stationary member operatively connected to the rotor shaft;
- a rotating member operatively connected to the rotor shaft, the rotating member being spaced from the stationary member by an air gap; and
- wherein the stationary member and the rotating member are configured to enable non-contact power transfer from the stationary member to the rotating member through the air gap.
2. The electric machine of claim 1, wherein:
- the inductive position sensor includes an inductive sensor board adapted to detect motion of the sensor target, the inductive sensor board being stationary; and
- the inductive sensor board includes a plurality of windings having transmitting coils and receiving coils.
3. The electric machine of claim 2, wherein the receiving coils include a positive first coil, a negative first coil, a positive second coil, and a negative second coil.
4. The electric machine of claim 1, further comprising:
- a rectifier circuit directly connected to the rotating member; and
- wherein the rotor assembly includes rotor windings electrically coupled with the rectifier circuit.
5. The electric machine of claim 1, wherein the stationary member includes a stationary core embedded with a first set of coils, the rotating member including a rotating core embedded with a second set of coils, and the non-contact power transfer between the stationary member and the rotating member is an inductive power transfer.
6. The electric machine of claim 5, wherein the sensor target is positioned directly on the rotor shaft along the central axis.
7. The electric machine of claim 5, wherein the sensor target is positioned circumferentially around the rotor shaft.
8. The electric machine of claim 5, wherein the sensor target is positioned circumferentially around the rotating core, the rotating core is positioned circumferentially around the rotor shaft, and the sensor target is etched on the rotating core.
9. The electric machine of claim 1, wherein the stationary member and the rotating member respectively include a stationary plate and a rotating plate positioned sufficiently close together to form a capacitor, such that the non-contact power transfer between the stationary member and the rotating member is a capacitive power transfer.
10. The electric machine of claim 9, wherein the sensor target is positioned directly on the rotor shaft along the central axis.
11. The electric machine of claim 9, wherein the sensor target is positioned circumferentially around the rotor shaft.
12. The electric machine of claim 9, wherein the sensor target is positioned circumferentially around the rotating plate, the rotating plate is positioned circumferentially around the rotor shaft, and the sensor target is etched on the rotating plate.
13. An electric machine comprising:
- a rotor assembly having a rotor shaft disposed along a central axis;
- an inductive position sensor having a sensor target operatively connected to the rotor shaft, the sensor target being fixed relative to the rotor shaft such that the sensor target rotates with the rotor shaft;
- a stationary member operatively connected to the rotor shaft;
- a rotating member operatively connected to the rotor shaft, the rotating member being spaced from the stationary member by an air gap;
- an inductive sensor board directly connected to the stationary member, the inductive sensor board being adapted to detect motion of the sensor target;
- a rectifier circuit directly connected to the rotating member, the rectifier circuit being adapted to converting alternating current voltage to direct current voltage;
- wherein the rotor assembly includes rotor windings electrically coupled to the rectifier circuit; and
- wherein the stationary member and the rotating member are configured to enable non-contact power transfer from the stationary member to the rotating member through the air gap.
14. The electric machine of claim 13, wherein the stationary member includes a stationary core embedded with a first set of coils, the rotating member includes a rotating core embedded with a second set of coils, and the non-contact power transfer between the stationary member and the rotating member is an inductive power transfer.
15. The electric machine of claim 14, wherein the sensor target is positioned directly on the rotor shaft along the central axis.
16. The electric machine of claim 14, wherein the sensor target is positioned circumferentially around the rotating core, the rotating core is positioned circumferentially around the rotor shaft, and the sensor target is etched on the rotating core.
17. The electric machine of claim 13, wherein the stationary member and the rotating member including respective metallic plates positioned sufficiently close together to form a capacitor, such that the non-contact power transfer between the stationary member and the rotating member is a capacitive power transfer.
18. The electric machine of claim 17, wherein the sensor target is positioned directly on the rotor shaft along the central axis.
19. The electric machine of claim 17, wherein the sensor target is positioned circumferentially around the rotor shaft.
20. A vehicle comprising:
- an electric machine including a rotor assembly having a rotor shaft disposed along a central axis;
- an inductive position sensor having a sensor target operatively connected to the rotor shaft and an inductive sensor board adapted to detect motion of the sensor target, the sensor target being fixed relative to the rotor shaft such that the sensor target rotates with the rotor shaft;
- a stationary member operatively connected to the rotor shaft, the stationary member including a stationary core embedded with a first set of coils;
- a rotating member operatively connected to the rotor shaft, the rotating member being spaced from the stationary member by an air gap, the rotating member including a rotating core embedded with a second set of coils;
- wherein the inductive sensor board is stationary and includes a plurality of windings having transmitting coils and receiving coils; and
- wherein the stationary member and the rotating member are configured to enable non-contact power transfer from the stationary member to the rotating member through the air gap.
Type: Application
Filed: Oct 6, 2023
Publication Date: Apr 10, 2025
Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC (Detroit, MI)
Inventors: Mazharul Chowdhury (Canton, MI), Muhammad A. Zahid (Troy, MI), Khorshed Mohammed Alam (Canton, MI), Suresh Gopalakrishnan (Troy, MI), Ajay Mehta (Auburn Hills, MI), Chandra S. Namuduri (Troy, MI)
Application Number: 18/482,212