Inductive position sensor
By introducing a resonant circuit and a receiving coil with a 90° phase difference into the inductive rotary position sensor, the problem of weak rotor signal of the copper foil array was solved, and the signal strength and signal-to-noise ratio were improved, enabling accurate calculation of rotor position.
Patent Information
- Application Number
- CN202520093608.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-15
- Publication Date
- 2025-12-23
- Estimated Expiration
- 2035-01-15
AI Technical Summary
In existing inductive rotary position sensors, the copper foil array used as the rotor suffers from weak eddy current reverse magnetic field signals and low signal-to-noise ratio.
By introducing a resonant circuit between the stator and the rotor, the induced magnetic field on the rotor is periodically distributed. Two sets of receiving coils with a 90° phase difference are set on the stator. The resonant current is used to enhance the high-frequency magnetic field, and the rotor position information is calculated by combining the arctangent method.
The induced voltage of the induction coil was increased, the signal strength was enhanced, the signal-to-noise ratio was improved, and the rotor's incremental and absolute position information could be accurately calculated.
Smart Images
Figure CN223710539U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to the field of sensor, concretely relates to a kind of amplitude type rotary position sensor of inductive principle. BACKGROUND
[0002] Common inductive rotary position sensor is composed of stator and rotor, and the stator is composed of PCB printed with excitation coil and several groups of induction coils, and the rotor is composed of PCB printed with corresponding copper foil array.The principle is that when high-frequency excitation signal is applied to the stator excitation coil, alternating magnetic field will be generated around it, and copper foil in the alternating magnetic field will generate eddy current counter magnetic field, and with the rotation of the rotor with copper foil array, angular displacement signal will be generated in the induction coil of the stator, as shown in FIG. Figure 1
[0003] However, the existing rotor using metal copper foil array has the following problems:
[0004] 1) External high-frequency signal will generate counter magnetic field on metal copper foil, causing the induction coil to be coupled to the undesired signal.
[0005] 2) The counter magnetic field generated by eddy current is usually weak, and the signal sensed by the induction coil is relatively weak, and the signal-to-noise ratio is not high. CONTENT OF THE UTILITY MODEL
[0006] The main purpose of the utility model is to provide an inductive position sensor, which generates resonance through the linkage of stator and rotor, and the rotor coil is suppressed outside the resonance, and the magnetic field generated by resonance is periodically distributed on the rotor, so that the original balanced induction magnetic field state of the receiving coil of the stator component is broken, and therefore the induction voltage of the odd and even coils is no longer equal, but changes with the rotational position of the rotor. The current of the coil is Q times of the total current during resonance, and the Q value can be improved by reasonable design of the coil, which can enhance the high-frequency magnetic field generated by the resonance current and improve the induction voltage of the receiving coil of the stator. When two groups of receiving coils with a phase difference of 90° are distributed on the stator, the incremental position information of the rotor can be obtained by arctangent method.
[0007] To achieve the above purpose, the utility model provides an inductive position sensor, which comprises a stator and a rotor, wherein:
[0008] The stator is provided with an excitation coil and at least two groups of receiving coils, each group of receiving coils on the stator is composed of 2m first sub-coils, and adjacent two first sub-coils are called a pair of poles, i.e. m pairs of poles, wherein all odd first sub-coils have consistent winding direction, all even first sub-coils have consistent winding direction, and the winding direction of odd first sub-coils and even first sub-coils is opposite, and the area is equal;
[0009] The rotor is provided with a resonance circuit, the resonance circuit comprises an induction coil which is wound and distributed so that the induced magnetic field on the rotor presents a periodic distribution, and the periodic distribution and the receiving coil on the stator correspond.
[0010] As a further preferred technical solution of the above technical solution, the induction coil of the rotor is wound in the first case, wherein:
[0011] The second sub-coil is divided into 2m, and adjacent two second sub-coils are called a pair of poles, that is, there are m pairs of poles, wherein the winding directions of all odd second sub-coils are consistent, the winding directions of all even second sub-coils are consistent, and the winding directions of the odd second sub-coils and the even second sub-coils are opposite;
[0012] As a further preferred technical solution of the above technical solution, the induction coil of the rotor is wound in the second case, wherein:
[0013] The second sub-coil is divided into 2m, and all second sub-coils are wound in the same direction, and the area of the induction coil of the odd second sub-coil is greater than that of the even second sub-coil, or the area of the induction coil of the even second sub-coil is greater than that of the odd second sub-coil.
[0014] As a further preferred technical solution of the above technical solution, the outer diameter and the inner diameter of the stator are respectively distributed with annular excitation coils, the winding directions of the excitation coils on the outer diameter and the inner diameter are opposite, the two groups of excitation coils are connected in series through PCB leads, the applied excitation is a sinusoidal excitation source with the same frequency f, the two excitation coils are two groups of receiving coils in space, which are in orthogonal relationship, the receiving coils are annular sinusoidal coils, and there are n pairs of poles in total, and the center of the two groups of receiving coils to the center of the stator is a radius R1.
[0015] The rotor corresponds to a position with a center radius R1, and is circumferentially distributed with square induction coils, adjacent odd and even square induction coils are a period, there are n periods in total, the odd coils are wound clockwise, and the even coils are wound counterclockwise, the odd and even coils are connected together through PCB leads, and the whole is arranged in an arch shape, and the ends of the induction coils are connected with capacitors, so that the resonance frequency of the capacitor and the induction coil is equal to f.
[0016] As a further preferred technical solution of the above technical solution, the outer diameter and the inner diameter of the stator are respectively distributed with annular excitation coils, the winding directions of the excitation coils on the outer diameter and the inner diameter are opposite, the two groups of excitation coils are connected in series through PCB leads, the applied excitation is a sinusoidal excitation source with the same frequency f, the two excitation coils are two groups of receiving coils in space, which are in orthogonal relationship, the receiving coils are annular sinusoidal coils, and there are n pairs of poles in total, and the center of the two groups of receiving coils to the center of the stator is a radius R1.
[0017] The rotor corresponds to the position of the center radius R1, and the square induction coils are distributed circumferentially, adjacent odd and even square induction coils are a period, there are n periods, the odd number is clockwise winding, the even number is also clockwise winding, and the wiring of the even number induction coil overlaps up and down, the horizontal area is 0, the odd and even induction coils are connected together through PCB lead, and the capacitors are connected at both ends of the induction coil, so that the resonance frequency of the capacitor and the induction coil is equal to f.
[0018] As a further preferred technical solution of the above technical solution, the outer diameter and the inner diameter of the stator are respectively distributed with annular excitation coils, the winding directions of the excitation coils on the outer diameter and the inner diameter are opposite, the two groups of excitation coils are connected in series through PCB lead, the excitation added is a sine excitation source with the same frequency f, the two excitation coils are two groups of receiving coils, which are in orthogonal relationship in space, each group of receiving coils is annular square coil, a total of n pairs of poles, the two groups of orthogonal square coils are arranged alternately with a phase difference of 90°, the winding directions of adjacent coils in each group are opposite, the radius of the center of the two groups of receiving coils to the center of the stator is R1;
[0019] The rotor corresponds to the position of the center radius R1, and the square induction coils are distributed circumferentially, adjacent odd and even square induction coils are a period, there are n periods, the odd number is clockwise winding, the even number is also clockwise winding, and the wiring of the even number induction coil overlaps up and down, the horizontal area is 0, the odd and even induction coils are connected together through PCB lead, and the capacitors are connected at both ends of the induction coil, so that the resonance frequency of the capacitor and the induction coil is equal to f.
[0020] As a further preferred technical solution of the above technical solution, the outer diameter and the inner diameter of the stator are respectively distributed with annular excitation coils, the winding directions of the excitation coils on the outer diameter and the inner diameter are opposite, the two groups of excitation coils are connected in series through PCB lead, the excitation added is a sine excitation source with the same frequency f, the excitation added is a sine excitation source with the same frequency f, the two excitation coils are two groups of receiving coils, which are in orthogonal relationship in space, each group of receiving coils is annular square coil, a total of n pairs of poles, the two groups of orthogonal square coils are arranged alternately with a phase difference of 90°, the winding directions of adjacent coils in each group are opposite, the radius of the center of the two groups of receiving coils to the center of the stator is R1;
[0021] The rotor has square induction coils distributed circumferentially at a center radius of R1. Adjacent odd and even square induction coils form a pair of poles, for a total of n pairs of poles. The odd-numbered coils are wound clockwise, and the even-numbered coils are wound counterclockwise. The even-numbered coils have overlapping vertical windings and a horizontal area of 0. The odd and even-numbered induction coils are connected together through PCB leads. Capacitors are connected to both ends of the induction coils, making the resonant frequency formed by the capacitors and the induction coils equal to f. At a center radius of R2, square induction coils are distributed circumferentially. Adjacent odd and even-numbered square coils form a pair of poles, for a total of n-1 pairs of poles. The odd-numbered coils are wound clockwise, and the even-numbered coils are wound counterclockwise. The odd and even-numbered induction coils are connected together through PCB leads. Capacitors are connected to both ends of the induction coils, making the resonant frequency formed by the capacitors and the induction coils equal to f. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of an existing sensor.
[0023] Figure 2 This is a schematic diagram of the first embodiment.
[0024] Figure 3 This is a schematic diagram of the second embodiment.
[0025] Figure 4 This is a schematic diagram of the third embodiment.
[0026] Figure 5 This is a schematic diagram of the fourth embodiment. Detailed Implementation
[0027] The following description is intended to disclose the present invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the present invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.
[0028] This utility model discloses an inductive position sensor. The specific embodiments of the utility model are further described below with reference to preferred embodiments.
[0029] In the embodiments of this utility model, those skilled in the art will note that the PCBs and the like involved in this utility model can be considered as prior art.
[0030] Preferred embodiment.
[0031] This invention discloses an inductive position sensor, comprising a stator and a rotor, wherein:
[0032] The stator is provided with an excitation coil and at least two sets of receiving coils. Each set of receiving coils on the stator consists of 2m (m is an integer greater than zero) first sub-coils. Two adjacent first sub-coils are called a pair of poles, that is, there are a total of m pairs of poles. All odd-numbered first sub-coils are wound in the same direction, all even-numbered first sub-coils are wound in the same direction, and the winding directions of odd-numbered first sub-coils and even-numbered first sub-coils are opposite, and their areas are equal (therefore, the induced voltage generated by the excitation coil of the stator on the stator receiving coil is theoretically 0).
[0033] The rotor is equipped with a resonant circuit, which includes an induction coil that is wound and distributed so that the induced magnetic field on the rotor presents a periodic distribution, and the periodic distribution corresponds to the receiving coil on the stator.
[0034] Specifically, the rotor's induction coil is wound according to the first scenario, wherein:
[0035] Divide into 2m (m is an integer greater than zero) second sub-coils. Two adjacent second sub-coils are called a pair of poles, that is, there are a total of m pairs of poles. All odd-numbered second sub-coils are wound in the same direction, all even-numbered second sub-coils are wound in the same direction, and the winding directions of odd-numbered and even-numbered second sub-coils are opposite.
[0036] More specifically, the rotor's induction coil is wound according to the second method, wherein:
[0037] Divide the system into 2m second sub-coils, with all second sub-coils wound in the same direction. The induction coil area of the odd-numbered second sub-coils should be greater than that of the even-numbered second sub-coils, or vice versa (the greater the difference in induction area, the better. In both cases, the design ensures that the resonant frequency of the rotor coils equals the frequency applied to the excitation coils on the stator).
[0038] When the rotor is positioned parallel to the front of the stator, the rotor coils resonate. Frequencies outside the resonance frequency are suppressed, and the magnetic field generated by the resonance is periodically distributed on the rotor. This disrupts the previously balanced induced magnetic field state of the receiving coils in the stator components. Consequently, the induced voltages of the odd and even coils are no longer equal but vary with the rotor's rotational position. At resonance, the coil current is Q times the total current. Proper coil design to increase the Q value can enhance the high-frequency magnetic field generated by the resonant current and increase the induced voltage of the stator receiving coils.
[0039] Thus, when two sets of receiving coils with a 90° phase difference are distributed on the stator (odd and even coils form a period of 360°), the incremental position information of the rotor can be obtained by arctangent method.
[0040] Furthermore, defining two sets of receiving coils with a 90° phase difference as a pair, there are two such pairs of receiving coils distributed radially, with M and N pole pairs respectively, and M and N are coprime. Correspondingly, two sets of induction coils are distributed radially on the rotor component, also with M and N pole pairs, which are coprime. By calculating the positions of the two code tracks M and N, the absolute position information of the rotor can be obtained.
[0041] A first embodiment is provided based on the preferred embodiment.
[0042] The stator has annular excitation coils distributed on its outer and inner diameters, respectively. The winding directions of the excitation coils on the outer and inner diameters are opposite (e.g., the outer coil is clockwise and the inner coil is counterclockwise). The two sets of excitation coils are connected in series via PCB leads. The applied excitation is a sinusoidal excitation source with the same frequency f. Between the two excitation coils are two sets of receiving coils, which are orthogonal in space. The receiving coils are annular sinusoidal coils with a total of n (preferably 16) pairs of poles (one sine and one cosine coil constitute one pair of poles, e.g., ...). Figure 2 As shown in a), the radius from the center of the two sets of receiving coils to the center of the stator is R1;
[0043] (like Figure 2 As shown in b), the rotor has square induction coils distributed circumferentially at a center radius of R1. Adjacent odd and even square induction coils form one cycle, for a total of n (preferably 16) cycles. Odd-numbered coils are wound clockwise, and even-numbered coils are wound counterclockwise (i.e., the corresponding induction coils are wound according to the first case). The odd and even coils are connected together via PCB leads, forming an overall bow-shaped arrangement. Capacitors are connected to both ends of the induction coils, such that the resonant frequency formed by the capacitors and the induction coils is equal to f. Therefore, the output voltage of the two receiving coils is:
[0044] Usin=K1SINθSIN(2Πft+Π / 2) Formula (1)
[0045] Ucos=K1COSθSIN(2Πft+Π / 2) Formula (2)
[0046] In the formula, K1 is a fixed parameter, θ is the angle between the rotor resonant coil and the stator receiving coil, and f is the frequency of the excitation coil. After demodulation, K2SINθ and K2COSθ can be obtained, and then θ can be obtained.
[0047] A second embodiment is provided based on the preferred embodiment.
[0048] The stator has annular excitation coils distributed on its outer and inner diameters, respectively. The winding directions of the excitation coils on the outer and inner diameters are opposite (e.g., the outer coil is clockwise and the inner coil is counterclockwise). The two sets of excitation coils are connected in series via PCB leads. The applied excitation is a sinusoidal excitation source with the same frequency f. Between the two excitation coils are two sets of receiving coils, which are orthogonal in space. The receiving coils are annular sinusoidal coils with a total of n (preferably 16) pairs of poles (one sine and one cosine coil constitute one pair of poles, e.g., ...). Figure 2 As shown in a), the radius from the center of the two sets of receiving coils to the center of the stator is R1;
[0049] (like Figure 3 As shown in a and b in the figure, the rotor has square induction coils distributed circumferentially at the position corresponding to the center radius R1. Adjacent odd and even square induction coils form one cycle, for a total of n (preferably 16) cycles. Odd-numbered coils are wound clockwise, and even-numbered coils are also wound clockwise (i.e., the corresponding induction coils are wound according to the second case). The wiring of even-numbered induction coils overlaps vertically, and the horizontal area is 0. Odd and even-numbered induction coils are connected together through PCB leads. Capacitors are connected to both ends of the induction coils, so that the resonant frequency formed by the capacitors and the induction coils is equal to f.
[0050] A third embodiment is provided based on the preferred embodiment.
[0051] The stator has annular excitation coils distributed on its outer and inner diameters, respectively. The winding directions of the excitation coils on the outer and inner diameters are opposite (e.g., the outer coil is wound clockwise, and the inner coil is wound counterclockwise). The two sets of excitation coils are connected in series via PCB leads. The applied excitation is a sinusoidal excitation source with the same frequency f. Between the two excitation coils are two sets of receiving coils, which are orthogonal in space. Each set of receiving coils is a square annular coil with n (preferably 16) pole pairs. The two sets of orthogonal square coils are arranged alternately with a phase difference of 90°. The winding directions of adjacent coils within each set are opposite (e.g., the outer coil is wound clockwise, and the inner coil is wound counterclockwise). Figure 4 As shown in a), the radius from the center of the two sets of receiving coils to the center of the stator is R1;
[0052] (like Figure 4 As shown in b), the rotor has sinusoidal induction coils distributed circumferentially at the position corresponding to the center radius R1. The adjacent positive half-cycle and negative half-cycle constitute one cycle, for a total of n (preferably 16) cycles. The positive half-cycle is wound clockwise, and the negative half-cycle is wound counterclockwise. Capacitors are connected to both ends of the induction coils, so that the resonant frequency formed by the capacitors and the induction coils is equal to f (so that the magnetic field directions generated by two adjacent induction coils are opposite due to the opposite winding directions, and the output voltage of the receiving coil on the corresponding rotor assembly is the same as that in equations (1) and (2)).
[0053] A fourth embodiment is provided based on the preferred embodiment.
[0054] (like Figure 5 As shown in (a), the stator has ring-shaped excitation coils distributed on its outer diameter, middle section, and inner diameter. The winding direction of the outer diameter coil is the same as that of the inner diameter coil, both being clockwise (counterclockwise). The winding direction of the middle section coil is counterclockwise (clockwise). The three sets of excitation coils are connected in series through PCB leads. The applied excitation is a sinusoidal excitation source with the same frequency f. Between the outer diameter coil and the middle section coil, there are n (preferably 16) pairs of pole orthogonal ring-shaped sinusoidal receiving coils. The radius from the center of the receiving coil to the center of the circle is R1. Between the inner diameter coil and the middle section coil, there are n-1 pairs of pole orthogonal ring-shaped sinusoidal receiving coils. The radius from the center of the receiving coil to the center of the circle is R2.
[0055] (like Figure 5 As shown in b), the rotor has square induction coils distributed circumferentially at the position corresponding to the center radius R1. Adjacent odd and even square induction coils form a pair of poles, for a total of n (preferably 16) pairs of poles. The odd ones are wound clockwise, and the even ones are wound counterclockwise. The even induction coils have overlapping vertically and a horizontal area of 0. The odd and even induction coils are connected together through PCB leads. Capacitors are connected to both ends of the induction coils, so that the resonant frequency formed by the capacitors and the induction coils is equal to f. At the position corresponding to the center radius R2, square induction coils are distributed circumferentially. Adjacent odd and even square coils form a pair of poles, for a total of n-1 (preferably 15) pairs of poles. The odd ones are wound clockwise, and the even ones are wound counterclockwise. The odd and even induction coils are connected together through PCB leads. Capacitors are connected to both ends of the induction coils, so that the resonant frequency formed by the capacitors and the induction coils is equal to f.
[0056] It is worth mentioning that the PCB and other technical features involved in this utility model patent application should be regarded as prior art. The specific structure, working principle, and possible control methods and spatial arrangement of these technical features can be adopted using conventional choices in the field, and should not be regarded as the inventive point of this utility model patent. This utility model patent will not elaborate further.
[0057] For those skilled in the art, modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. An inductive position sensor, comprising a stator and a rotor, characterized in that, in: The stator is provided with an excitation coil and at least two sets of receiving coils. Each set of receiving coils on the stator consists of 2m first sub-coils. Two adjacent first sub-coils are called a pair of poles, that is, there are a total of m pairs of poles. All odd-numbered first sub-coils are wound in the same direction, all even-numbered first sub-coils are wound in the same direction, and the winding directions of odd-numbered first sub-coils and even-numbered first sub-coils are opposite, and their areas are equal. The rotor is equipped with a resonant circuit, which includes an induction coil that is wound and distributed so that the induced magnetic field on the rotor presents a periodic distribution, and the periodic distribution corresponds to the receiving coil on the stator.
2. The inductive position sensor according to claim 1, characterized in that, The rotor's induction coil is wound according to the first case, wherein: Divide into 2m second sub-coils. Two adjacent second sub-coils are called a pair of poles, that is, there are a total of m pairs of poles. All odd-numbered second sub-coils are wound in the same direction, all even-numbered second sub-coils are wound in the same direction, and the winding directions of odd-numbered and even-numbered second sub-coils are opposite.
3. The inductive position sensor according to claim 1, characterized in that, The rotor's induction coil is wound according to the second scenario, wherein: Divide into 2m second sub-coils, all of which are wound in the same direction, and ensure that the induction coil area of the odd-numbered second sub-coils is greater than that of the even-numbered second sub-coils, or vice versa.
4. The inductive position sensor according to claim 2, characterized in that, The stator has annular excitation coils distributed on its outer and inner diameters, with the winding directions of the excitation coils on the outer and inner diameters being opposite. The two sets of excitation coils are connected in series through PCB leads. The applied excitation is a sinusoidal excitation source with the same frequency f. Between the two excitation coils are two sets of receiving coils, which are orthogonal in space. The receiving coils are annular sinusoidal coils with a total of n pairs of poles. The radius from the center of the two sets of receiving coils to the center of the stator is R1. The rotor has square induction coils distributed circumferentially at a center radius of R1. Adjacent odd and even square induction coils form one cycle, for a total of n cycles. Odd coils are wound clockwise, and even coils are wound counterclockwise. Odd and even coils are connected together through PCB leads, and the whole arrangement is in a bow shape. Capacitors are connected to both ends of the induction coils, so that the resonant frequency formed by the capacitors and the induction coils is equal to f.
5. The inductive position sensor according to claim 3, characterized in that, The stator has annular excitation coils distributed on its outer and inner diameters, with the winding directions of the excitation coils on the outer and inner diameters being opposite. The two sets of excitation coils are connected in series through PCB leads. The applied excitation is a sinusoidal excitation source with the same frequency f. Between the two excitation coils are two sets of receiving coils, which are orthogonal in space. The receiving coils are annular sinusoidal coils with a total of n pairs of poles. The radius from the center of the two sets of receiving coils to the center of the stator is R1. The rotor has square induction coils distributed circumferentially at a center radius of R1. Adjacent odd and even square induction coils form one cycle, for a total of n cycles. Odd-numbered coils are wound clockwise, and even-numbered coils are also wound clockwise. The windings of even-numbered induction coils overlap vertically, resulting in a horizontal area of 0. Odd and even-numbered induction coils are connected together via PCB leads. Capacitors are connected to both ends of the induction coils, such that the resonant frequency formed by the capacitors and the induction coils is equal to f.
6. The inductive position sensor according to claim 1, characterized in that, The stator has annular excitation coils distributed on its outer and inner diameters, with the winding directions of the excitation coils on the outer and inner diameters being opposite. The two sets of excitation coils are connected in series through PCB leads. The applied excitation is a sinusoidal excitation source with the same frequency f. Between the two excitation coils are two sets of receiving coils, which are orthogonal in space. Each set of receiving coils is an annular square coil with a total of n pairs of poles. The two sets of orthogonal square coils are arranged alternately with a phase difference of 90°. The winding directions of adjacent coils in each set are opposite. The radius from the center of the two sets of receiving coils to the center of the stator is R1. The rotor has sinusoidal induction coils circumferentially distributed at a position corresponding to the center radius R1. Each adjacent positive half-cycle and negative half-cycle constitutes one cycle, for a total of n cycles. The positive half-cycle is wound clockwise, and the negative half-cycle is wound counterclockwise. Capacitors are connected to both ends of the induction coils, such that the resonant frequency formed by the capacitors and the induction coils is equal to f.
7. The inductive position sensor according to claim 1, characterized in that, The stator has ring-shaped excitation coils distributed on its outer diameter, middle section, and inner diameter. The outer diameter coil is wound in the same clockwise direction as the inner diameter coil, while the middle section coil is wound counterclockwise. The three sets of excitation coils are connected in series through PCB leads. The applied excitation is a sinusoidal excitation source with the same frequency f. There are n pairs of orthogonal ring-shaped sinusoidal receiving coils distributed between the outer diameter coil and the middle section coil. The radius from the center of the receiving coil to the center of the circle is R1. There are n-1 pairs of orthogonal ring-shaped sinusoidal receiving coils distributed between the inner diameter coil and the middle section coil. The radius from the center of the receiving coil to the center of the circle is R2. The rotor has square induction coils distributed circumferentially at a center radius of R1. Adjacent odd and even square induction coils form a pair of poles, for a total of n pairs of poles. The odd-numbered coils are wound clockwise, and the even-numbered coils are wound counterclockwise. The even-numbered coils have overlapping vertical windings and a horizontal area of 0. The odd and even-numbered induction coils are connected together through PCB leads. Capacitors are connected to both ends of the induction coils, making the resonant frequency formed by the capacitors and the induction coils equal to f. At a center radius of R2, square induction coils are distributed circumferentially. Adjacent odd and even-numbered square coils form a pair of poles, for a total of n-1 pairs of poles. The odd-numbered coils are wound clockwise, and the even-numbered coils are wound counterclockwise. The odd and even-numbered induction coils are connected together through PCB leads. Capacitors are connected to both ends of the induction coils, making the resonant frequency formed by the capacitors and the induction coils equal to f.