Inductive sensor, electric motor and vehicle applying the same

Abstract

The application provides an inductive sensor, a motor and a vehicle, comprising a coaxial induction rotor and a stator coil, the stator coil comprising a transmitting coil and a receiving coil, wherein the induction rotor comprises a first conductor coil and N petal-shaped conductors, the first conductor coil has N petal-shaped coils which are uniformly distributed, each petal-shaped coil corresponds to a petal-shaped conductor, and each petal-shaped conductor is not in contact with the first conductor coil; and N is an integer greater than or equal to 1. The application combines the whole mechanical period and the single electric period, and can achieve a small angular deviation effect when the gap between the induction rotor and the stator coil changes.

Description

Technical Field

[0001] This invention relates to the field of power electronics, and particularly to an inductive sensor, a motor, and a vehicle using the same. Background Technology

[0002] The general principle of an inductive sensor used for angle measurement is as follows: an excitation coil generates a high-frequency magnetic field, inducing eddy currents in an induction coil or solid conductor. The displacement or angle is then measured by a receiving coil. Therefore, this type of sensor mainly consists of three parts: a transmitting coil (TX), a receiving coil (RX), and an induction coil (IX). Typically, the transmitting and receiving coils are mounted on a fixed circuit board / printed board, which is usually called the stator. The induction coil is mounted on a rotating board that rotates with the rotating board, which is called the rotor. The stator and rotor are coaxially arranged. The rotation of the rotor causes changes in the induced eddy currents generated by the induction coil, affecting the change in the magnetic field received by the receiving coil. The rotor's rotation angle or displacement is measured based on the induced electromotive force generated by the receiving coil.

[0003] An integrated circuit is connected to the receiving coil interface. In the angle sensor, the received signal generated by the receiving coil has the characteristics of odd harmonics. During signal processing, the integrated circuit can eliminate the 3rd, 9th, and 15th harmonics by subtracting the three-phase signals pairwise through an algorithm. The 5th, 7th, 11th, and 13th harmonics are still present. The presence of these harmonics seriously affects the accuracy of angle / displacement measurement.

[0004] Figure 1 The diagram illustrates the principle of an existing inductive rotor, which refers to a rotatable inductive conductor with three blades, each blade hollow in the center. In a sensor, this inductive rotor can correspond to... Figure 2 The transmitting coil 1 and receiving coil 2 in the circuit can receive signals whose fifth harmonic can affect the accuracy of angle measurement. At the same time, the angle will also be offset during the change of the gap between the stator and the rotor. For example, if the gap changes by about 1 mm, the electrical angle deviation will be about ±1 degree, which will seriously affect the accuracy of the measured angle. Summary of the Invention

[0005] The purpose of this invention is to provide an inductive sensor, motor, and vehicle that can suppress harmonics, reduce angular offset caused by changes in rotor-stator gap, and improve the accuracy of angle measurement.

[0006] This invention proposes an inductive sensor, comprising an inductive rotor and a stator coil arranged coaxially. The stator coil includes a transmitting coil and a receiving coil, wherein...

[0007] The induction rotor includes a first conductor coil and N petal-shaped conductors. The first conductor coil has N petal-shaped wires evenly distributed around the central axis. Each petal-shaped wire corresponds to one of the petal-shaped conductors. Each petal-shaped conductor does not contact the first conductor coil.

[0008] N is an integer greater than or equal to 1.

[0009] Optionally, one mechanical cycle is divided into N equal electrical cycles, wherein the first conductor coil covers the entire mechanical cycle, and each electrical cycle has a corresponding lobe-shaped conductor.

[0010] Optionally, the lobe-shaped conductor is one of a coil, a metal sheet, or a combination of a coil and a metal sheet.

[0011] Optionally, the first conductor coil also has N arc-shaped wires evenly distributed around the central axis, with each pair of adjacent arc-shaped wires extending radially to form two radial sides of the corresponding petal-shaped wire, and the petal-shaped wire also having arc-shaped sides connected to the two radial sides.

[0012] The N arc-shaped wires and the N lobe-shaped wires together form a closed first conductor coil.

[0013] Optionally, the arcuate sides of the N lobe-shaped conductors together define a discontinuous outer circular coil around the central axis.

[0014] Optionally, N arc-shaped conductors together define a discontinuous inner circular coil around the central axis.

[0015] Optionally, a petal-shaped conductor is disposed on the inner side of each petal-shaped wire, the inner arc of the petal-shaped conductor is located between two adjacent arc-shaped wires, and the outer arc of the petal-shaped conductor is close to the outer arc of the petal-shaped wire.

[0016] The two radial sides of the lobe-shaped conductor are respectively close to the two radial sides of the corresponding lobe-shaped wire.

[0017] Optionally, the inner arc of the lobe-shaped conductor is located on the circumference of the inner circular coil.

[0018] Optionally, a petal-shaped conductor is provided between every two petal-shaped wires, with the inner arc of the petal-shaped conductor close to the corresponding arc-shaped wire, and the outer arc of the petal-shaped conductor located between the outer arcs of the two petal-shaped wires.

[0019] The two radial sides of the lobe-shaped conductor are respectively close to the radial sides of the adjacent lobe-shaped wire.

[0020] Optionally, the outer arc of the petal-shaped conductor is located on the circumference of the outer circular coil.

[0021] Optionally, the transmitting coil is a circular ring coil, and the radius of the transmitting coil is greater than the first radius;

[0022] The first radius is equal to the average of the radius of the inner circular coil and the radius of the outer circular coil.

[0023] Optionally, the transmitting coil is located outside the receiving coil.

[0024] Optionally, the transmitting coil is a circular ring coil, and the radius of the transmitting coil is smaller than the first radius;

[0025] The first radius is equal to the average of the radius of the inner circular coil and the radius of the outer circular coil.

[0026] Optionally, the transmitting coil is located inside the receiving coil.

[0027] Optionally, each of the petal-shaped conductors has a first angle between its two radial sides, a second angle between each pair of petal-shaped conductors, and a third angle between its two radial sides, the vertices of the first angle, the second angle, and the third angle being located at the center line of the central axis;

[0028] The first angle is A1, the second angle is A2, and the third angle is A3, where A1 = (3 / 5) × (360 / N) and A2 = A3 = (2 / 5) × (360 / N).

[0029] Optionally, each of the petal-shaped conductors has a first angle between its two radial sides, a second angle between each pair of petal-shaped conductors, and a third angle between its two radial sides, the vertices of the first angle, the second angle, and the third angle being located at the center line of the central axis;

[0030] The first angle is A1, the second angle is A2, and the third angle is A3, where A1 = A3 = (2 / 5) × (360 / N) and A2 = (3 / 5) × (360 / N).

[0031] The present invention also proposes a motor, including a housing, a rotating shaft, and any one of the inductive sensors described above, wherein the inductive rotor of the inductive sensor is fixed to the rotating shaft, and the stator coil of the angle sensor is directly or indirectly fixed to the housing.

[0032] The present invention also proposes a vehicle comprising the motor described above.

[0033] Compared with the prior art, the present invention has the following advantages: The induction rotor (induction coil / induction conductor) set by the present invention includes a first conductor coil and multiple lobe conductors. The first conductor coil covers a complete mechanical cycle, and the multiple lobe conductors cover multiple corresponding electrical cycles. When the gap between the stator and the rotor changes, the angle offset error is small, and the fifth harmonic of the received signal can be effectively suppressed within a large gap change range, thereby improving the accuracy of angle measurement. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of an existing induction rotor.

[0035] Figure 2 This is a schematic diagram of an embodiment of a stator coil;

[0036] Figure 3 This is a schematic diagram of Embodiment 1 of the first induction rotor of the present invention;

[0037] Figure 4 This is a schematic diagram of Embodiment 2 of the first induction rotor of the present invention;

[0038] Figure 5 This is a schematic diagram of Embodiment 3 of the first induction rotor of the present invention;

[0039] Figure 6 A schematic diagram of another embodiment of the stator coil;

[0040] Figure 7 This is a schematic diagram of Embodiment 1 of the second type of induction rotor of the present invention;

[0041] Figure 8 This is a schematic diagram of Embodiment 2 of the second type of induction rotor of the present invention;

[0042] Figure 9 This is a schematic diagram of Embodiment 3 of the second type of induction rotor of the present invention. Detailed Implementation

[0043] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the present invention is not limited to these embodiments. The present invention covers any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of the present invention.

[0044] To provide the public with a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments of the invention, but those skilled in the art can fully understand the invention without these details.

[0045] This invention designs an induction coil / conductor based on existing transmitting coils (also called excitation coils) and receiving coils. The transmitting coil and receiving coil are set on a fixed circular circuit board / printed board (stator) according to certain design rules. In this invention, the transmitting coil and receiving coil are collectively referred to as stator coils. The induction coil / conductor is set on a rotatable circuit board / printed board (rotor) and rotates accordingly with the rotating circuit board. The stator and rotor are coaxially arranged, and the rotor rotates around a central axis. The center line of the central axis is the central axis line. In this invention, the induction coil / conductor set on the rotatable circuit board is called the induction rotor.

[0046] See Figure 2 This diagram illustrates a conventional stator coil schematic, including a transmitting coil 01 and a receiving coil 02, arranged around a central axis 03. The transmitting coil is a circular winding, and the receiving coil is a three-strand coil with a staggered sinusoidal or quasi-sinusoidal distribution, located inside the transmitting coil. Alternatively, a receiving coil can be further arranged outside the transmitting coil. The stator coil of this invention can employ... Figure 2 The schematic diagram illustrates the coil type, but the receiving coil of the present invention is not limited to a sinusoidal or quasi-sinusoidal distribution, and may also be rectangular, circular or polygonal. The present invention does not limit the winding method, pattern, etc. of the receiving coil.

[0047] The errors of inductive sensors can be divided into electro-periodic errors and mechanical periodic errors. Electro-periodic errors are mainly caused by harmonics in the received signal generated by the receiving coil, DC signal offset, integrated circuit signal processing, and some installation errors. Mechanical periodic errors are mainly caused by installation errors. The harmonics of the received signal generally vary with the gap between the rotor and the receiving coil (stator). In some types of receiving coils, higher harmonics are lower when the gap is smaller, while in other types of receiving coils, higher harmonics are lower when the gap is larger. This invention, by setting the structure of the inductive rotor, combines the entire mechanical cycle and the electrical cycle, which can reduce the angle deviation caused by gap changes, effectively suppress the 5th harmonic of the received signal, and improve the accuracy of angle measurement.

[0048] The inductive stator of this invention includes a first conductor coil and N petal-shaped conductors. The first conductor coil has N petal-shaped wires evenly distributed around its central axis. Each of the N petal-shaped conductors corresponds to one of the N petal-shaped wires, and the N petal-shaped conductors do not contact the first conductor coil. N is an integer greater than or equal to 1. One mechanical cycle of this invention is divided into N electrical cycles. The first conductor coil covers the entire mechanical cycle, and each electrical cycle has a corresponding petal-shaped conductor. Whether the N petal-shaped conductors are located inside or outside the N petal-shaped wires depends on the radius Φ3 of the transmitting coil. See also... Figure 3 , Figure 4 , Figure 5Let's take an example where N is 4 and the radius of the transmitting coil is greater than the first radius for further explanation.

[0049] See Figure 3 This diagram illustrates the principle of Embodiment 1 of the first type of induction rotor of the present invention, including a first conductor coil 04 and four petal-shaped conductors 05. Each petal-shaped conductor in this embodiment is a hollow coil. The first conductor coil 04 includes four arc-shaped wires 41 and four petal-shaped wires (composed of 42 and 43). Radial extension between every two adjacent arc-shaped wires forms two radial sides 42 of a corresponding petal-shaped wire. The arc-shaped sides 43 of the petal-shaped wires connect the two radial sides 42. The four arc-shaped wires 41 together define a discontinuous inner circular coil with a radius of Φ1. The arc-shaped sides of the four petal-shaped wires together define a discontinuous outer circular coil with a radius of Φ2. The first radius is the average of Φ1 and Φ2. The petal-shaped conductors 05 include an outer arc 51, an inner arc 52, and two radial sides 53. When the radius of the transmitting coil is greater than the first radius, each petal-shaped conductor is located inside the corresponding petal-shaped wire. See the attached diagram for details. Figure 3 The inner arc 52 of the petal-shaped conductor is located between the two arc-shaped wires 41. The outer arc 51 of the petal-shaped conductor is close to the arc-shaped side 43 of the petal-shaped wire of the first conductor coil. The two radial sides 53 of the petal-shaped conductor are respectively close to the two radial sides 42 of the corresponding petal-shaped wires. The inner arc of the petal-shaped conductor and the arc-shaped wire of the first conductor coil are located on the same circumference around the central axis, which is the circumference of the inner coil. When the transmitting coil is larger than the first radius, the magnetic field generated by the transmitting coil and the induced magnetic field generated in the first conductor coil and the petal-shaped conductor are in the same direction (the directions of the generated currents I1 and I2 are as follows). Figure 3 (As shown), therefore each lobe conductor is positioned inside the corresponding lobe wire. See also Figure 3 The first conductor coil has a first angle A1 between its two radial sides of the petal-shaped conductor, a second angle A2 between its two adjacent petal-shaped conductors, a third angle A3 between its two radial sides of the petal-shaped conductor, and a fourth angle A4 and a fifth angle A5 between its two radial sides and the two radial sides of the petal-shaped conductor, respectively. A1, A2, A3, A4, and A5 are all non-zero, and the endpoints of the angles are at the central axis. Optionally, A4 = A5. Optionally, A1 = (3 / 5) * (360 / N), A2 = A3 = (2 / 5) * (360 / N), A4 = A5 = (1 / 10) * (360 / N).

[0050] Optionally, A1 = (3 / 5)*(360 / N), A2 = (2 / 5)*(360 / N), A3 = (1 / 2)*(360 / N), A4 = A5 = (1 / 20)*(360 / N), where N is 4 in this embodiment. The angle A3 of the lobe conductor in the lobe-shaped wire, whether (2 / 5)*(360 / N) or (1 / 2)*(360 / N), has little impact on the angle deviation; in practice, a suitable angle can be selected based on the actual situation. In this embodiment, a mechanical cycle is divided into 4 electrical cycles. A portion of the first conductor coil (arc-shaped wire) in the induction rotor is 2 / 5 of the electrical cycle, and another portion (lobe-shaped wire) is 3 / 5 of the electrical cycle, which can effectively reduce the 5th harmonic of the received signal. The lobe-shaped conductor in the induction rotor is mainly used to reduce the angular offset (angular error) when the gap between the stator and rotor changes. When the gap increases, the absolute angle generated by the lobe-shaped conductor is reverse bias, while the absolute angle generated by the first conductor coil is forward bias. By properly configuring the first conductor coil and the lobe-shaped conductor, a very small absolute angular offset can be generated with the change of gap.

[0051] Figure 4 , Figure 5 The schematic diagrams of embodiments 2 and 3 of the first induction rotor of the present invention are shown respectively, and are related to... Figure 3 The illustrated embodiment 1 is identical to the previous one except for the lobe-shaped conductor, and will not be described again here. The lobe-shaped conductor, except for the type shown... Figure 3 The petal-shaped coil shown (with a hollow center) can also be as follows: Figure 4 The petal-shaped metal sheet shown (solid metal) can also be as follows: Figure 5 The combination of the metal sheet and the coil shown (with part of the coil being solid and part being hollow) allows the size of the solid part of the lobe conductor to be adjusted according to the simulation accuracy of angle detection, so as to achieve high angle detection accuracy.

[0052] See Figure 6 Another embodiment of the stator coil is shown in the schematic diagram. The transmitting coil 01 is a circular coil arranged around the central axis 03. The radius Φ3 of the transmitting coil is smaller than the first radius. A receiving coil 2 is arranged outside the transmitting coil. The receiving coil in the figure is sinusoidally distributed. In this invention, the distribution shape of the receiving coil is not limited.

[0053] See Figure 7 This illustrates the principle of Embodiment 1 of the second type of induction rotor of the present invention, and... Figure 3 The first type of induction rotor shown has a first conductor coil 04 and a petal-shaped conductor 05 with the same shape, which will not be described further here. The difference lies in the fact that, since the radius Φ3 of the transmitting coil is smaller than the first radius, which is the average of Φ1 and Φ2, the relative positions of the first conductor coil and the petal-shaped conductor are... Figure 3 Inconsistent Figure 6In the first conductor coil, the petal-shaped conductor 05 is located between the two petal-shaped wires (42 and 43). Specifically, the inner arc 52 of the petal-shaped conductor is close to the corresponding arc 41 of the first conductor coil 04, and the outer arc 52 of the petal-shaped conductor and the outer arc 43 of the petal-shaped wire are located on the same circumference around the central axis. This circumference is the circumference of the outer circular coil, with a radius of Φ2. The two radial sides 53 of the petal-shaped conductor are close to the radial sides 42 of the adjacent petal-shaped wires. When the transmitting coil is smaller than the first radius, the magnetic field generated by the transmitting coil induces the magnetic field in the first conductor coil and the petal-shaped conductor in opposite directions (the directions of the generated currents I1 and I2 are as follows). Figure 7 (As shown), therefore each lobe conductor is positioned between two adjacent lobe conductors. See also Figure 7 The first conductor coil has a first angle A1 between its two radial sides, a second angle A2 between its two adjacent petal-shaped conductors, a third angle A3 between its two radial sides, and a fourth angle A4 and a fifth angle A5 between its two radial sides and the radial sides of its adjacent petal-shaped conductors, respectively. A1, A2, A3, A4, and A5 are all non-zero and the endpoints of the angles are at the central axis. Optionally, A4 = A5, A1 = A3, A1 = A3 = (2 / 5)*(360 / N), A2 = (3 / 5)*(360 / N), A4 = A5 = (1 / 10)*(360 / N), or A1 = (2 / 5)*(360 / N), A2 = (3 / 5)*(360 / N), A3 = (1 / 2)*(360 / N). In this embodiment, N is 4. and Figure 3 Similarly, this embodiment can also reduce the harmonics of the received signal and the angle deviation caused by gap variations.

[0054] Figure 8 , Figure 9 The schematic diagrams of embodiments 2 and 3 of the second type of induction rotor of the present invention are shown respectively, and are related to... Figure 7 The illustrated embodiment 1 is identical to the previous one except for the lobe-shaped conductor, and will not be described again here. The lobe-shaped conductor, except for the type shown... Figure 7 The petal-shaped coil shown (with a hollow center) can also be as follows: Figure 8 The petal-shaped metal sheet shown (solid metal) can also be as follows: Figure 9 The combination of the metal sheet and the coil shown (with part of the coil being solid and part being hollow) allows for adjustment of the solid size of the lobe-shaped conductor according to the simulation accuracy, thereby achieving high angle detection accuracy.

[0055] This invention combines a mechanically periodic first conductor coil with an electrically periodic lobe-shaped conductor, resulting in almost no absolute angle drift when the gap between the stator and rotor changes. Common solutions on the market cannot achieve the same effect as this invention.

[0056] The invention is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. It should be noted that the drawings are in a simplified form and use non-precise proportions, in order to facilitate and clearly illustrate the purpose of the embodiments of the invention.

[0057] Although the embodiments are described and illustrated separately above, some common technologies are involved. Those skilled in the art can replace and integrate them between the embodiments. If there is any content not explicitly described in one embodiment, then another embodiment that is described can be referred to.

[0058] The embodiments described above do not constitute a limitation on the scope of protection of this technical solution. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the above embodiments should be included within the scope of protection of this technical solution.

Claims

1. An inductive sensor, characterized in that, It includes an induction rotor and stator coils arranged concentrically on a central axis. The stator coils include a transmitting coil and a receiving coil, wherein... The induction rotor includes a first conductor coil and N petal-shaped conductors. The first conductor coil has N petal-shaped wires evenly distributed around the central axis. Each petal-shaped wire corresponds to one of the petal-shaped conductors. Each petal-shaped conductor does not contact the first conductor coil. N is an integer greater than or equal to 1.

2. The inductive sensor according to claim 1, characterized in that: One mechanical cycle corresponds to N equal electrical cycles, wherein the first conductor coil covers the complete mechanical cycle, and each electrical cycle has a corresponding lobe-shaped conductor.

3. The inductive sensor according to claim 1 or 2, characterized in that: The lobe-shaped conductor is one of a coil, a metal sheet, or a combination of a coil and a metal sheet.

4. The inductive sensor according to claim 3, characterized in that: The first conductor coil also has N arc-shaped wires evenly distributed around the central axis, and each pair of adjacent arc-shaped wires extends radially to form two radial sides of the corresponding petal-shaped wire, and the petal-shaped wire also has arc-shaped sides connected to the two radial sides; The N arc-shaped wires and the N lobe-shaped wires together form a closed first conductor coil.

5. The inductive sensor according to claim 4, characterized in that: The arcuate sides of N lobe-shaped wires together define a discontinuous outer circular coil around the central axis.

6. The inductive sensor according to claim 5, characterized in that: N curved wires together define a discontinuous inner circular coil around the central axis.

7. The inductive sensor according to claim 6, characterized in that: A petal-shaped conductor is disposed on the inner side of each petal-shaped wire, the inner arc of the petal-shaped conductor is located between two adjacent arc-shaped wires, and the outer arc of the petal-shaped conductor is close to the outer arc of the petal-shaped wire. The two radial sides of the lobe-shaped conductor are respectively close to the two radial sides of the corresponding lobe-shaped wire.

8. The inductive sensor according to claim 7, characterized in that: The inner arc of the petal-shaped conductor is located on the circumference of the inner circular coil.

9. The inductive sensor according to claim 6, characterized in that: A petal-shaped conductor is provided between every two petal-shaped wires, with the inner arc of the petal-shaped conductor close to the corresponding arc-shaped wire, and the outer arc of the petal-shaped conductor located between the outer arcs of the two petal-shaped wires. The two radial sides of the lobe-shaped conductor are respectively close to the radial sides of the adjacent lobe-shaped wire.

10. The inductive sensor according to claim 9, characterized in that: The outer arc of the petal-shaped conductor is located on the circumference of the outer circular coil.

11. The inductive sensor according to claim 7, characterized in that: The transmitting coil is a circular ring coil, and the radius of the transmitting coil is greater than the first radius; The first radius is equal to the average of the radius of the inner circular coil and the radius of the outer circular coil.

12. The inductive sensor according to claim 11, characterized in that: The transmitting coil is located outside the receiving coil.

13. The inductive sensor according to claim 9, characterized in that: The transmitting coil is a circular ring coil, and the radius of the transmitting coil is smaller than the first radius; The first radius is equal to the average of the radius of the inner circular coil and the radius of the outer circular coil.

14. The inductive sensor according to claim 13, characterized in that: The transmitting coil is located inside the receiving coil.

15. The inductive sensor according to claim 7, characterized in that: Each of the petal-shaped conductors has a first angle between its two radial sides, a second angle between each pair of petal-shaped conductors, and a third angle between its two radial sides, the vertices of the first angle, the second angle, and the third angle being located at the center line of the central axis; The first angle is A1, the second angle is A2, and the third angle is A3, wherein... A1=(3 / 5)×(360 / N), A2=A3=(2 / 5)×(360 / N).

16. The inductive sensor according to claim 9, characterized in that: Each of the petal-shaped conductors has a first angle between its two radial sides, a second angle between each pair of petal-shaped conductors, and a third angle between its two radial sides, the vertices of the first angle, the second angle, and the third angle being located at the center line of the central axis; The first angle is A1, the second angle is A2, and the third angle is A3, wherein... A1=A3=(2 / 5)×(360 / N), A2=(3 / 5)×(360 / N).

17. An electric motor, characterized in that: The device includes a housing, a rotating shaft, and an inductive sensor as described in any one of claims 1-16, wherein the inductive rotor of the inductive sensor is fixed to the rotating shaft, and the stator coil of the angle sensor is directly or indirectly fixed to the housing.

18. A vehicle, characterized in that: Includes the motor as described in claim 17.

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