Position sensor for motor and motor system

Abstract

The embodiment of the invention provides a position sensor for a motor and a motor system, the motor comprises a stator and a rotor, the position sensor comprises a transmitting coil, the transmitting coil and the stator are relatively fixedly arranged, and the transmitting coil comprises a plurality of annular and concentrically arranged coils and a resonant capacitor connected with the coils in parallel; the transmission coil and the rotor are relatively and fixedly arranged, the size of the transmission coil is smaller than that of the transmitting coil, and the projection of the transmission coil in a plane perpendicular to the direction of a motor shaft is located in the projection range of the transmitting coil; and the at least two groups of receiving coils are fixedly arranged relative to the stator, and the phase difference between the groups of receiving coils is set at an angle.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to a position sensor for a motor and a motor system. Background Art

[0002] In a motor, the position of the rotor needs to be obtained in real time to drive the motor. Currently, all known rotor position detection methods are to install a rotor position sensor on the motor. Common position sensors include Hall elements, magnetic encoders, photoelectric encoders, resolvers, etc.

[0003] These position sensors are usually installed on the motor shaft to detect the position of the rotor. However, when the motor is in a harsh environment, such as high temperature, high pressure and high vibration, the reliability of position detection will be greatly affected. Summary of the invention

[0004] The present application provides a position sensor for a motor and a motor system with high detection reliability.

[0005] In a first aspect of the present application, a position sensor for a motor is provided, wherein the motor comprises a stator and a rotor, and the position sensor comprises:

[0006] A transmitting coil is fixedly arranged relative to the stator, and the transmitting coil includes a plurality of annular and concentrically arranged coils and a resonant capacitor connected in parallel with the coils;

[0007] A transmission coil is fixedly arranged relative to the rotor, the size of the transmission coil is smaller than that of the transmitting coil, and the projection of the transmission coil in a plane perpendicular to the motor shaft direction is located within the projection range of the transmitting coil;

[0008] At least two groups of receiving coils are fixedly arranged relative to the stator, and the phase difference between the receiving coils in each group is a set angle.

[0009] In a second aspect of the present application, a motor system is provided, comprising a motor and the position sensor described in any embodiment of the present application; wherein the transmitting coil and the receiving coil are fixedly arranged relative to the stator, and the transmitting coil is fixedly arranged relative to the rotor.

[0010] In the above embodiment, the position sensor includes a transmitting coil and at least two groups of receiving coils arranged relatively fixedly with the stator, and a transmission coil arranged relatively fixedly with the rotor. The inductance of the transmitting coil itself and the capacitance connected in parallel therewith form an LC resonant circuit. After the initial excitation is applied, the LC resonant circuit generates a high-frequency sinusoidal current in the transmitting coil, and then generates a high-frequency sinusoidal magnetic field in space. The transmission coil follows the rotation of the rotor, and the induced voltage excited in the receiving coil by the high-frequency sinusoidal magnetic field generated by the transmission coil is used to accurately feedback the position information of the rotor. In this way, the position sensor is based on Faraday's law of electromagnetic induction, and achieves the purpose of reflecting the position of one of the coils (i.e., the rotor) through the mutual excitation conversion of the electric field and the magnetic field between the transmitting coil, the transmission coil and the receiving coil, and the interaction between the magnetic fields. Even if the motor is in harsh environments such as high temperature, high pressure and high vibration, it can still ensure good position detection accuracy and reliability.

[0011] The motor system provided in the above embodiment belongs to the same concept as the corresponding position sensor embodiment, and thus has the same technical effect as the corresponding position sensor embodiment, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Schematic diagram of the principle of a position sensor in one embodiment.

[0013] Figure 2 FIG. 4 is a schematic diagram of a transmitting coil in one embodiment.

[0014] Figure 3 Schematic diagram of a transmitting coil and a transmitting coil in one embodiment.

[0015] Figure 4 Schematic diagram of a transmitting coil and a receiving coil in one embodiment.

[0016] Figure 5 Schematic diagram of a transmitting coil and a receiving coil in one embodiment.

[0017] Figure 6 Schematic diagram of a transmitting coil, a transmitting coil, and a receiving coil of a position sensor for a linear motor in one embodiment.

[0018] Figure 7 Schematic diagram of a transmitting coil, a transmitting coil, and a receiving coil of a position sensor for a rotary motor in one embodiment.

[0019] Figure 8 FIG. 1 is a schematic diagram of a transmitting coil, a transmitting coil, and a receiving coil of a position sensor for a rotary motor in another embodiment.

[0020] Fig. 9Schematic diagram of the conversion principle between the receiving coil of a linear motor and the receiving coil of a rotary motor in one embodiment.

[0021] Fig.10 Schematic diagram of the structure of a position sensor in one embodiment.

[0022] Fig.11 for Fig.10 Schematic diagram of the exploded structure of the position sensor shown.

[0023] Fig.12 for Fig.10 The schematic diagram of the arrangement of the transmitting coil and the receiving coil on the sensor stator circuit board in the position sensor is shown.

[0024] Fig.13 FIG. 1 is a wiring diagram of a top wiring layer of a sensor stator circuit board in one embodiment.

[0025] Fig.14 for Fig.13 Layout diagram of the bottom wiring layer of the sensor stator circuit board shown.

[0026] Fig.15 for Fig.13 The wiring diagram of the transmitter coil and two sets of receiving coils on the sensor stator circuit board is shown. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0028] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. The described embodiments should not be regarded as limiting the present application. All other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of this application.

[0029] In the following description, the expression "some embodiments" is involved, which describes a subset of all possible embodiments. It should be noted that "some embodiments" may be the same subset or different subsets of all possible embodiments, and may be combined with each other without conflict.

[0030] It should also be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may also be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "inside", "outside", "left", "right" and similar expressions used herein are only for the purpose of explanation in conjunction with the embodiments of the accompanying drawings and do not represent the only implementation method.

[0031] A motor refers to an electromagnetic device that realizes the conversion or transmission of electric energy according to the law of electromagnetic induction. The main components of a motor include a stator and a rotor that moves relative to the stator. It should be noted that common types of motors mainly include linear motors and rotary motors. The motion states of the parts that move relative to the stator in different motor types are different. The parts that move relative to the stator in a linear motor are linear motion, generally referred to as movers, and the parts that move relative to the stator in a rotary motor are rotary motion, generally referred to as rotors. In the embodiments of the present application, for the sake of ease of description, the parts that move relative to the stator in the motor are collectively referred to as rotors. At this time, the rotor should be understood in a broad sense, including movers in linear motors and rotors in rotary motors.

[0032] See also Figure 1 , a position sensor 50 for a motor 40 provided in an embodiment of the present application, the motor 40 includes a stator 41 and a rotor 42, and the position sensor 50 includes: a transmitting coil 10, which is fixedly arranged relative to the stator 41, and the transmitting coil 10 includes a plurality of annular and concentrically arranged coils and a resonant capacitor connected in parallel with the coil; a transmitting coil 20, which is fixedly arranged relative to the rotor 42, the size of the transmitting coil 20 is smaller than the transmitting coil 10, and the projection of the transmitting coil 20 in a plane perpendicular to the motor axis direction is located within the projection range of the transmitting coil 10; at least two groups of receiving coils 30, which are fixedly arranged relative to the stator 41, and the phase difference between each group of receiving coils 30 is set by a set angle.

[0033] The transmitting coil 10 and the receiving coil 30 are both fixedly arranged relative to the stator 41 of the motor 40, and the transmission coil 20 is fixedly arranged relative to the rotor 42 of the motor 40. The size of the transmission coil 20 is smaller than that of the transmitting coil 10, and the projection of the transmission coil 20 in a plane perpendicular to the motor axis direction is located within the projection range of the transmitting coil 10. In this way, the induced voltage excited in the receiving coil 30 by the high-frequency sinusoidal magnetic field generated by the transmission coil 20 following the rotation of the rotor 42 can be output through the receiving coil 30. The position sensor 50 can be connected to an external processing circuit, and the output voltage in the receiving coil 30 is processed by the external processing circuit to decompose a signal that can reflect the rotor position.

[0034] Among them, with the plane perpendicular to the motor axis direction as a reference, the projection of the transmitting coil 10 in the plane and the projection of the receiving coil 30 in the plane are respectively arranged symmetrically. The size of the transmitting coil 20 is smaller than that of the transmitting coil 10, and the projection of the transmitting coil 20 in the plane is arranged asymmetrically, so that the induced voltage excited in the receiving coil 30 by the high-frequency sinusoidal magnetic field generated by the transmitting coil 10 is also symmetrical, so that they can cancel each other, so that the output voltage of the receiving coil 30 mainly includes the characteristic signal of the rotor position detection, which can simplify the processing of the output voltage by the external processing circuit, so that it is easier to determine the rotor position according to the output voltage of the receiving coil 30.

[0035] In the above embodiment, the position sensor 50 includes a transmitting coil 10 and at least two groups of receiving coils 30 fixedly arranged relative to the stator 41, and a transmitting coil 20 fixedly arranged relative to the rotor 42. The inductance of the transmitting coil 10 itself and the resonant capacitor are connected in parallel to form an LC resonant circuit. After the initial excitation is applied, the LC resonant circuit generates a high-frequency sinusoidal current in the transmitting coil 10, and then generates a high-frequency sinusoidal magnetic field in space. The transmitting coil 20 rotates with the rotor 42, and the high-frequency sinusoidal magnetic field generated by the transmitting coil 20 generates an induced voltage in the receiving coil 30 to accurately feedback the rotor position information. In this way, the position sensor 50 is based on Faraday's law of electromagnetic induction, and achieves the purpose of reflecting the position of one of the coils (i.e., the rotor 42) through the mutual excitation conversion of the electric field and the magnetic field between the transmitting coil 10, the transmitting coil 20 and the receiving coil 30, and the interaction between the magnetic fields. Even if the motor 40 is in a harsh environment such as high temperature, high pressure and high vibration, it can still ensure good position detection accuracy and reliability.

[0036] The position sensor 50 achieves the purpose of feeding back the position of the transmission coil 20 through the mutual excitation conversion of the electric field and the magnetic field between the transmitting coil 10, the transmitting coil 20 and the receiving coil 30, and the interaction between the magnetic fields. In the position sensor 50, the transmitting coil 10 and the receiving coil 30 are both installed on the stator side of the motor 40 and are physically stationary in space, while the transmitting coil 20 is installed on the rotor side of the motor 40 and moves with the rotor 42 in space. The rotor position is determined based on the output voltage of the receiving coil 30, which is mainly calculated by using the asymmetric induced voltage generated by the transmitting coil 20 relative to the receiving coil 30. The working principle of the position sensor 50 is as follows: a high-frequency sinusoidal current is passed through the transmitting coil 10, and the high-frequency sinusoidal current excites a first high-frequency sinusoidal magnetic field Be that changes with time in space; the transmitting coil 20 rotates in the first high-frequency sinusoidal magnetic field Be following the rotor 42, generating a high-frequency sinusoidal current flowing in the transmitting coil 20, and exciting a second high-frequency sinusoidal magnetic field Bt that changes simultaneously with time and space in space; the second high-frequency sinusoidal magnetic field Bt passes through the receiving coil 30 in space, and excites an output voltage in which a high-frequency voltage signal and a low-frequency voltage signal are superimposed in the receiving coil 30; the low-frequency voltage signal in the output voltage is used to determine the rotor position; wherein, high frequency means that the frequency is greater than the target value.

[0037] In an optional example, the working principle of the position sensor 50 is as follows:

[0038] First, a high-frequency sinusoidal current that varies with time is passed through the transmitting coil 10. According to Faraday's law of electromagnetic induction, the high-frequency sinusoidal current will excite a high-frequency sinusoidal magnetic field that varies with time in space. For the convenience of distinction and description, it is referred to as the first high-frequency sinusoidal magnetic field Be in the embodiment of the present application.

[0039] Secondly, the high-frequency sinusoidal magnetic field generated by the transmitting coil 10 passes through the transmitting coil 20 in space, and will excite a high-frequency sinusoidal voltage that varies with time in the transmitting coil 20. Since the transmitting coil 20 is a closed loop, a high-frequency sinusoidal current that varies with time will be generated and flow in the transmitting coil 20; and since the transmitting coil 20 moves with the movement of the rotor 42 of the motor 40, the high-frequency sinusoidal current in the transmitting coil 20 varies not only with time but also with space. Therefore, the high-frequency sinusoidal current in the transmitting coil 20 will also excite a high-frequency sinusoidal magnetic field that varies with both time and space in space. For the sake of distinction and description, it is referred to as the second high-frequency sinusoidal magnetic field Bt in the embodiment of the present application.

[0040] Again, the high-frequency sinusoidal magnetic field generated by the transmitting coil 20, which varies with time and space, passes through the receiving coil 30 in space, and will excite an output voltage with high frequency and low frequency superposition in the receiving coil 30. The high-frequency voltage part reflects the high-frequency variation of the sinusoidal magnetic field in time, and the low-frequency voltage part reflects the low-frequency variation of the sinusoidal magnetic field in space.

[0041] Finally, the output voltage signal in the receiving coil 30 is decoupled through an external processing circuit, and the low-frequency voltage signal portion obtained by decomposition reflects the rotor position of the motor 40.

[0042] Optionally, the receiving coil 30 includes two groups of coils with a phase difference of 90°, or three groups of coils with a phase difference of 120°. In combination with the description of the working principle of the above position sensor 50, it can be known that after the multiple groups of receiving coils 30 with a phase difference of a set angle are processed by an external processing circuit, decoupling can obtain two or three signals, which can improve the rotor position detection accuracy and detect the movement direction of the rotor 42.

[0043] It should be noted that the position sensor 50 provided in the embodiment of the present application is suitable for both linear motors and rotary motors. Under the technical guidance of the working principle of the above-mentioned position sensor 50, designers can combine the motion characteristics of linear motors and rotary motors to adaptively adjust the design of the shapes of the transmitting coil 10, the transmitting coil 20 and the receiving coil 30 accordingly.

[0044] Please refer to Figures 2 to 6 In some embodiments, taking the motor 40 as a linear motor, the transmitting coil 10 is a hollow rectangle, and the size of the transmitting coil 20 is half of the transmitting coil 10. It should be noted that the transmitting coil 20 may be aligned with one end of the transmitting coil 10 in the initial position. During the operation of the motor 40, the transmitting coil 20 moves relative to the transmitting coil 10 and forms different alignment states with the transmitting coil 10 from one end to the other. Figure 3 , the transmitting coil 10 can be designed as several concentric coils, which can be regarded as an inductor L. The equivalent inductor L of the transmitting coil 10 is connected in parallel with a capacitor C. After the initial energy is applied, an LC resonant circuit will be formed. After the initial excitation is applied, this resonant circuit will generate a high-frequency sinusoidal current ie in the transmitting coil 10, and its frequency f is:

[0045]

[0046] Among them, Figure 4The projection of the receiving coil 30 in a plane perpendicular to the motor axis direction is located within the projection range of the transmitting coil 10. The receiving coil 30 includes a positive coil 31 and a negative coil 32 in a sinusoidal wave shape. The positive coil 31 and the negative coil 32 together form the shape of an infinity symbol, and the length and width of the infinity symbol are approximately equal to the length and width of the transmitting coil 10, respectively.

[0047] Since the receiving coil 30 is very close to the transmitting coil 10 and the transmitting coil 20, the first high-frequency sinusoidal magnetic field Be generated by the transmitting coil 10 and the second high-frequency sinusoidal magnetic field Bt generated by the transmitting coil 20 will both pass through the receiving coil 30 in space. In this embodiment, the receiving coil 30 in the shape of an infinity symbol adopts a double-loop design of a series twisted type. In this way, the first high-frequency sinusoidal magnetic field Be generated by the transmitting coil 10 excites an induced voltage ur1 in the receiving coil 30, as shown in FIG. Figure 4 , the first high-frequency sinusoidal magnetic field Be passing through the transmitting coil 10 will excite the double loops to produce induced voltages ur1-1 and ur1-2 of the same magnitude and opposite polarity. When the double loops are connected in series, the induced voltages ur1-1 and ur1-2 cancel each other out, so the total output voltage ur1 of the receiving coil 30 is zero; in addition, if Figure 5 Since the transmission coil 20 is only half the size of the receiving coil 30, no matter where the rotor 42 is in the movement, the transmission coil 20 cannot completely cover the double loop range of the receiving coil 30. Figure 5 The transmitting coil 20 covers different parts of the left and right double loops of the receiving coil 30. The double loops are stimulated by the second high-frequency sinusoidal magnetic field Bt to produce induced voltages ur2-1 and ur2-2 of different sizes. The two cannot be completely offset, so the total output voltage ur2 of the receiving coil 30 is not zero.

[0048] According to the motion characteristics of the linear motor, when the transmitting coil 20 moves left and right relative to the receiving coil 30 following the movement of the rotor 42, the areas covered by the second high-frequency sinusoidal magnetic field Bt of the left and right double loops of the receiving coil 30 increase and decrease. Therefore, the amplitude of the output high-frequency sinusoidal voltage ur2 of the receiving coil 30 will show a lower-frequency sinusoidal change as the position of the transmitting coil 20 changes, such as Figure 5 As shown by the dotted curve of the voltage ur2 at the bottom of the middle right figure, the second high-frequency sinusoidal magnetic field Bt generated by the transmitting coil 20 generates a stable output of the induced voltage ur2 in the receiving coil 30. After the voltage signal ur2 is decoupled by the external processing circuit, it can accurately feedback the position of the transmitting coil 20, that is, the rotor position information of the linear motor.

[0049] See also Figure 6, is an optional specific example, when the motor 40 is a linear motor, a wiring diagram of the transmitting coil 10, the transmitting coil 20 and the receiving coil 30. Among them, the transmitting coil 10 is a hollow rectangle, the transmitting coil 20 is one half of the transmitting coil 10, and is aligned with one end of the transmitting coil 10. The receiving coil 30 includes three sets of coils in the shape of an infinite symbol with a phase difference of 120°, and can output three sinusoidal induced voltage signals with a phase difference of 120° using a high-frequency sine wave as a carrier. After decoupling processing, this voltage signal can accurately feedback the position information of the linear motor mover.

[0050] Please refer to Figures 7 and 8 In some embodiments, taking the motor 40 as a rotary motor as an example, the transmitting coil 10 is hollow and circular, and the outer contour of the transmitting coil 20 includes at least one arc segment arranged in the circumferential direction of the transmitting coil 10. According to the rotation characteristics of the rotor 42 in the rotary motor, the transmitting coil 20 generally needs to be designed to be smaller than the transmitting coil 10 and partially aligned with the transmitting coil 10 based on the assembly characteristics of the rotor 42 shaft.

[0051] In an alternative example, Figure 7 , the transmission coil 20 includes a sector-shaped portion 21 having a size half that of the transmitting coil 10 and a connecting portion 22 arranged around the motor shaft. For a rotary motor, the transmitting coil 10 is in the shape of a ring that matches the outer contour of the stator 41 of the motor 40, and the transmission coil 20 is also formed in a sector shape accordingly. The number of transmission coils 20 is equal to the number of pole pairs of the motor 40. If the motor 40 has multiple pole pairs, a sector-shaped transmission coil 20 can be arranged corresponding to each pole pair and connected in series. Figure 8 The transmission coil 20 includes a plurality of outer arc segments 231 arranged in the circumferential direction corresponding to the transmitting coil 10, a plurality of inner arc segments 232 arranged in the circumferential direction around the motor shaft, and a connecting segment 233 connecting the adjacent outer arc segments 231 and inner arc segments 232; wherein the inner arc segments 232 and the outer arc segments 231 are staggered in the circumferential direction. For example, if the motor 40 includes 5 pairs of poles, the number of the outer arc segments 231 is 5, which are arranged one by one corresponding to the 5 pairs of poles of the motor 40.

[0052] The shape of the receiving coil 30 can be designed to be a circular ring that matches the outer contour of the stator 41 according to the outer contour of the stator 41 of the rotary motor. Figure 7The receiving coil 30 includes three groups of coils with a phase difference of 120°, which are distinguished by green, red and blue colors respectively. Each group of receiving coils 30 includes a positive coil 31 and a negative coil 32 in a circular shape smaller than the transmitting coil 10. The positive coil 31 and the negative coil 32 in each group of receiving coils 30 are arranged axially symmetrically. In this way, the double rings of each group of receiving coils 30 are relative to the transmitting coil 10. The induced voltages excited by the first high-frequency sinusoidal magnetic field Be generated by the transmitting coil 10 can offset each other, while the second high-frequency sinusoidal magnetic field Bt generated by the transmitting coil 20 excites induced voltages ur2-1 and ur2-2 of different magnitudes. The two cannot be completely offset and are output through the receiving coil 30 to calculate the rotor position.

[0053] like Figure 8 The receiving coil 30 includes three groups of coils with a phase difference of 120°, which are distinguished by green, red and blue colors respectively. Each group of receiving coils 30 includes a positive coil 31 and a negative coil 32 in a sinusoidal wave shape. The troughs of the positive coil 31 and the negative coil 32 are located on the same circular ring surrounding the outer periphery of the motor shaft, and the peaks are located on the same circular ring near the inner periphery of the transmitting coil 10. In this embodiment, each group of receiving coils 30 is still symmetrically arranged relative to the transmitting coil 10. For each group of receiving coils 30, relative to the transmitting coil 10, the induced voltages excited by the first high-frequency sinusoidal magnetic field Be generated by the transmitting coil 10 can cancel each other, while the second high-frequency sinusoidal magnetic field Bt generated by the transmitting coil 20 excites induced voltages ur2-1 and ur2-2 of different magnitudes, which cannot be completely offset and are output through the receiving coil 30 to calculate the rotor position.

[0054] The receiving coil 30 in the linear mode is in the shape of a sine wave. The trajectory expression of the receiving coil 30 in the linear mode can be converted into the trajectory expression of the receiving coil 30 in the rotating mode by coordinate transformation. Fig. 9 The middle left figure shows the receiving coil 30 of the sensor of a linear motor with a pole pair number of 4. The solid line sinusoidal curve R(θ) and the dashed line sinusoidal curve R′(θ) can be expressed as Formula 1 and Formula 2 respectively:

[0055] R(θ)=1 / 2(Ro+Ri)+1 / 2(Ro-Ri)sin(pθ); (Formula 1)

[0056] R′(θ)=1 / 2(Ro+Ri)-1 / 2(Ro-Ri)sin(pθ); (Formula 2)

[0057] Where Ro and Ri are the maximum and minimum values ​​relative to the horizontal axis respectively.

[0058] like Fig. 9 In the middle right figure, the calculation is shown in the following formula 3 and formula 4:

[0059] x=R(θ)cos(θ); y=R(θ)sin(θ); (Formula 3)

[0060] x′=R′(θ)cos(θ); y′=R′(θ)sin(θ); (Formula 4)

[0061] The sine component and cosine component of R(θ) and R′(θ) can be calculated respectively, and the receiving coil 30 of the position sensor 50 of the rotary motor with four pairs of poles can be obtained.

[0062] Please refer to Figures 10 to 12 In the position sensor 50, the wiring design of the transmitting coil 10, the transmitting coil 20 and the receiving coil 30 can be implemented based on the PCB circuit board. In some embodiments, the transmitting coil 10 and the receiving coil 30 are both formed on the sensor stator circuit board 51, and the transmitting coil 20 is formed on the sensor rotor circuit board 52; wherein, the sensor stator circuit board 51 includes multiple wiring layers, the transmitting coil 10 is located on the same wiring layer, and in each group of receiving coils 30, a through hole 511 is provided at the overlapping position of the positive coil 31 and the negative coil 32, and the coil segments located on both sides of the through hole 511 are arranged in different wiring layers by penetrating the through hole 511. wherein, the transmitting coil 10 and the receiving coil 30 can be integrally arranged on the same sensor stator circuit board 51, such as Fig.12 The mechanical frame shape of the sensor stator circuit board 51 (PCB) is roughly the same as the outer contour of the stator 41 of the rotary motor. The transmitting coil 10 includes a plurality of concentrically arranged annular coils, and the receiving coil 30 includes three groups, each group of receiving coils 30 includes coils for sinusoidal voltage signals and cosine voltage signals. The sensor stator circuit board 51 is composed of two wiring layers, such as a top wiring layer 512 and a bottom wiring layer 513. The transmitting coil 10 is a plurality of concentric ring coils, which are arranged in the same wiring layer of the sensor stator circuit board 51, such as the top wiring layer 512. The positive coil 31 and the negative coil 32 of the receiving coil 30 are respectively in the shape of wavy lines, and there are multiple intersections between each other. By setting a through hole 511 at each intersection or in front of the position to be crossed, each receiving coil 30 starts from the starting end and moves on one of the wiring layers on the sensor stator circuit board 51. When encountering the through hole 511, it passes through the through hole 511 and then conducts to another wiring layer to continue moving. In this way, the wiring is repeated back and forth between the two wiring layers, so as to realize the arrangement of the receiving coil 30 without cross conduction.

[0063] The sensor rotor circuit board 52 can be formed into a shape corresponding to the transfer coil 20. In this embodiment, taking the transfer coil 20 designed for the four pairs of poles in the rotary motor as an example, the sensor rotor circuit board 52 is a metal plate, and its outer contour is consistent with the outer contour of the transfer coil 20. The metal plate can be regarded as a plurality of concentric transfer coils 20 stacked in a circle, from the outside to the inside, and connected in series end to end, with a through hole 521 in the middle, and is pressed onto the rotor 42 shaft of the motor 40 by tight fit.

[0064] In some embodiments, the position sensor 50 further includes a housing cover 53, in which the sensor stator circuit board 51 is potted and arranged in the housing cover 53, and a mounting portion 531 for being assembled to the stator 41 is provided on the housing cover 53; the sensor rotor circuit board 52 is mounted on the shaft of the rotor 42 by tight fit. The housing cover 53 may be a plastic cover, and after the sensor stator circuit board 51 is mounted on the housing cover 53, the sensor stator circuit board 51 may be completely potted and wrapped in the cavity of the housing cover 53 by potting glue, so as to isolate the sensor stator circuit board 51 from contact with the external environment and prevent failure; the sensor stator circuit board 51 may be screwed and mounted to the stator 41 of the motor 40 through the mounting portion 531 on the housing cover 53, which specifically includes three positioning mounting holes.

[0065] See also Figures 13 to 15 , Fig.13 A schematic diagram showing the circuit of the top wiring layer 512 on the sensor stator circuit board 51 after the transmitter coil 10 and the receiver coil 30 are arranged;

[0066] Fig.14 A schematic diagram showing the circuit of the bottom wiring layer 513 on the sensor stator circuit board 51 after the receiving coil 30 is arranged; Fig.15 The schematic diagram of the circuit is shown after the top wiring layer 512 and the bottom wiring layer 513 of the sensor stator circuit board 51 are arranged and superimposed on the transmitting coil 10 and the receiving coil 30. It can be seen that the position sensor 50 provided in the embodiment of the present application includes a design scheme of a transmitting coil 10, a transmitting coil 20 and a receiving coil 30, and a design method of using a sensor stator circuit board 51 and a sensor rotor circuit board 52 to achieve the required shape and size of the transmitting coil 10, the transmitting coil 20 and the receiving coil 30. The product form of the position sensor 50 is simple and easy to implement, the coil wiring design is orderly, very neat and beautiful, and the reliability of achieving the rotor position detection accuracy of the motor 40 is high.

[0067] On the other hand, the present application further provides a motor system, including a motor 40 and a position sensor 50 in an embodiment of the present application; wherein the transmitting coil 10 and the receiving coil 30 are relatively fixedly arranged with respect to the stator 41, and the transmitting coil 20 is relatively fixedly arranged with respect to the rotor 42.

[0068] The motor 40 may be a linear motor or a rotary motor.

[0069] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0070] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A position sensor for a motor, the motor comprising a stator and a rotor, characterized in that: The position sensor comprises: A transmitting coil is fixedly arranged relative to the stator, and the transmitting coil includes a plurality of annular and concentrically arranged coils and a resonant capacitor connected in parallel with the coils; A transmission coil is fixedly arranged relative to the rotor, the size of the transmission coil is smaller than that of the transmitting coil, and the projection of the transmission coil in a plane perpendicular to the motor shaft direction is located within the projection range of the transmitting coil; At least two groups of receiving coils are fixedly arranged relative to the stator, and the phase difference between the receiving coils in each group is a set angle.

2. The position sensor according to claim 1, characterized in that: The receiving coil includes two groups of coils with a phase difference of 90°, or three groups of coils with a phase difference of 120°.

3. The position sensor according to claim 1, characterized in that: The motor is a linear motor; The transmitting coil is in the shape of a hollow rectangle, and the size of the transmitting coil is half of that of the transmitting coil.

4. The position sensor according to claim 3, characterized in that: The projection of the receiving coil in a plane perpendicular to the motor axis direction is located within the projection range of the transmitting coil. The receiving coil includes a positive coil and a negative coil in a sinusoidal wave shape. The positive coil and the negative coil together form the shape of an infinity symbol, and the length and width of the infinity symbol are approximately equal to the length and width of the transmitting coil, respectively.

5. The position sensor according to claim 1, characterized in that: The motor is a rotary motor; The transmitting coil is in the shape of a hollow circle, and the outer contour of the transmitting coil includes at least one arc segment arranged in a circumferential direction corresponding to the transmitting coil.

6. The position sensor according to claim 5, characterized in that: The transfer coil comprises a sector portion whose size is half of that of the transmitting coil and a connecting portion arranged around the motor shaft.

7. The position sensor according to claim 5, characterized in that: The transmission coil includes a plurality of outer arc segments arranged in the circumferential direction corresponding to the transmitting coil, a plurality of inner arc segments arranged in the circumferential direction surrounding the motor shaft, and a connecting segment connected between adjacent outer arc segments and inner arc segments; Wherein, the inner arc segment and the outer arc segment are staggered in the circumferential direction.

8. The position sensor according to claim 5, characterized in that: The receiving coil includes three groups of coils with a phase difference of 120°; Each group of the receiving coils includes a positive coil and a negative coil in a circular shape smaller than the transmitting coil, and the positive coil and the negative coil in each group of the receiving coils are arranged axially symmetrically; or, each group of the receiving coils includes a positive coil and a negative coil in a sinusoidal wave shape, and the troughs of the positive coil and the negative coil are located on the same circular ring surrounding the periphery of the motor shaft, and the peaks are located on the same circular ring close to the inner periphery of the transmitting coil.

9. The position sensor according to any one of claims 1 to 8, characterized in that: The transmitting coil and the receiving coil are both formed on a sensor stator circuit board, and the transmitting coil is formed on a sensor rotor circuit board; Among them, the sensor stator circuit board includes multiple wiring layers, the transmitting coil is located on the same wiring layer, and in each group of the receiving coils, a through hole is provided at the overlapping position of the positive coil and the negative coil, and the coil segments located on both sides of the through hole are arranged in different wiring layers by penetrating the through hole.

10. The position sensor according to claim 9, characterized in that: It also includes a housing cover, the sensor stator circuit board is potted and arranged in the housing cover, and the housing cover is provided with a mounting portion for assembling to the stator; The sensor rotor circuit board is mounted on the rotor shaft by tight fitting.

11. The position sensor according to any one of claims 1 to 8, characterized in that: A high-frequency sinusoidal current is passed through the transmitting coil, and the high-frequency sinusoidal current excites a first high-frequency sinusoidal magnetic field that varies with time in space; The transfer coil rotates with the rotor in the first high-frequency sinusoidal magnetic field, generates a high-frequency sinusoidal current flowing in the transfer coil, and spatially excites a second high-frequency sinusoidal magnetic field that changes simultaneously with time and space; The second high-frequency sinusoidal magnetic field passes through the receiving coil in space, and excites an output voltage in the receiving coil that is a superposition of a high-frequency voltage signal and a low-frequency voltage signal; the low-frequency voltage signal in the output voltage is used to determine the position of the rotor; Here, high frequency means that the frequency is greater than the target value.

12. A motor system, characterized in that: It comprises a motor and a position sensor as claimed in any one of claims 1 to 11; wherein the transmitting coil and the receiving coil are fixedly arranged relative to the stator, and the transmitting coil is fixedly arranged relative to the rotor.

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