Magnetic encoders and motors

Abstract

A magnetic encoder and motor, relating to the technical field of encoders, include: a magnetic assembly comprising a first magnet and a second magnet fixed to a motor shaft, the first magnet having a pair of magnetic poles, the second magnet being arranged around the first magnet and having multiple pairs of magnetic poles arranged circumferentially, the first magnet being located at the center of the circumference; a first magnetic induction sensor corresponding to the first magnet, used to sense changes in the magnetic field of the first magnet to obtain a first induction signal; at least two identical second magnetic induction sensors, used to sense changes in the magnetic field of the second magnets to obtain multiple second induction signals; and a circuit board with a main chip disposed on the circuit board, the main chip being electrically connected to the first and second magnetic induction sensors, used to process the received first induction signal and multiple second induction signals. This facilitates the elimination of position feedback errors caused by mechanical installation errors.

Description

Technical Field

[0001] This application relates to the technical field of encoders, specifically to a magnetic encoder and motor. Background Technology

[0002] An electric motor is a device that converts electrical energy into mechanical energy, widely used in various mechanical equipment, automation systems, and household appliances. Electric motors contain encoders that monitor the motor's rotational position and speed. One type of encoder is the magnetic encoder, which contains a magnetic induction sensor to sense changes in the direction and intensity of the magnetic field of the code disk, converting it into a measurable electrical signal. This signal is then conditioned by the main chip's subsequent processing circuitry to generate position feedback information ranging from 0 to 360 degrees. However, mechanical installation errors can occur during the production and assembly of the magnetic code disk. These errors can cause periodic variations in the encoder's output position information, resulting in inaccuracies in the magnetic encoder's position feedback. Utility Model Content

[0003] This application provides a magnetic encoder and motor that can solve the problem of position feedback error in magnetic encoders.

[0004] According to one aspect of this application, one embodiment provides a magnetic encoder, comprising: A magnetic component includes a first magnet and a second magnet fixed to a motor shaft. The first magnet has a pair of magnetic poles, and the second magnet is disposed around the first magnet. The second magnet has multiple pairs of magnetic poles arranged in a circular pattern, and the first magnet is located at the center of the circumference. A first magnetic induction sensor, which corresponds to the first magnet, is used to sense changes in the magnetic field of the first magnet to obtain a first induction signal. At least two identical second magnetic induction sensors are used to sense changes in the magnetic field of the second magnet to obtain multiple second induction signals; and A circuit board with a main chip on it, the main chip being electrically connected to the first magnetic induction sensor and the second magnetic induction sensor, for processing the received first induction signal and multiple second induction signals.

[0005] In one embodiment, the magnetic encoder includes two second magnetic induction sensors, which are symmetrically disposed on opposite sides of the second magnet.

[0006] In one embodiment, the magnetic encoder includes three second magnetic induction sensors, which are evenly distributed circumferentially. Alternatively, it may include three second magnetic induction sensors, wherein two second magnetic induction sensors are symmetrically arranged on opposite sides of the second magnet, and the three second magnetic induction sensors are located on the same circumference; Alternatively, it may include four second magnetic induction sensors located on the same circumference, with two of the second magnetic induction sensors distributed along one diameter line of the second magnet and the other two distributed along another diameter line of the second magnet.

[0007] In one embodiment, the first magnet is disc-shaped or ring-shaped, and the second magnet is provided with multiple pairs of magnetic poles evenly arranged in a circle to form a ring-shaped second magnet.

[0008] In one embodiment, the magnetic encoder further includes a support member, which includes a magnetic support portion and a connecting portion connected to one end of the magnetic support portion. The magnetic support portion has a first groove and a second groove on the side away from the connecting portion. The first groove is located in the middle of the magnetic support portion and is used to install the first magnet. The second groove is located on the outer periphery of the magnetic support portion and is used to install the second magnet. The connecting portion is used to fix and connect with the motor shaft.

[0009] In one embodiment, the sides of the first magnet and the second magnet that are away from the connecting portion are flush with the side of the magnetic support that is away from the connecting portion.

[0010] In one embodiment, the system further includes a bracket, with the circuit board connected to one end of the bracket. The first magnetic induction sensor and a plurality of second magnetic induction sensors are fixed on the circuit board. The bracket has a receiving cavity, and the support member is used to be inserted into the receiving cavity so that the first magnet corresponds to the first magnetic induction sensor, and the second magnet corresponds to the second magnetic induction sensor.

[0011] In one embodiment, the second magnetic sensor is located at one end of the first magnet closer to the circuit board; Alternatively, the circuit board may have at least two mounting portions on the side near the second magnet. The mounting portions are L-shaped, with one straight arm connected to the circuit board and a second magnetic induction sensor correspondingly disposed on the other straight arm. The mounting portions are located on the outer periphery of the second magnet so that the second magnetic induction sensor corresponds to the outer periphery sidewall of the second magnet.

[0012] In one embodiment, the second magnet has 8, 12, or 16 pairs of magnetic poles.

[0013] According to another aspect of this application, one embodiment provides a motor, including a motor shaft and a magnetic encoder as described above, wherein the first magnet and the second magnet are both fixed to the motor shaft.

[0014] The magnetic encoder and motor according to the above embodiments include a first magnet and a second magnet for fixing to the motor shaft. A first magnetic induction sensor is used to sense changes in the magnetic field of the first magnet to obtain a first induction signal. At least two second magnetic induction sensors are used to sense changes in the magnetic field of the second magnet to obtain multiple second induction signals. The main chip combines the received first induction signals and multiple second induction signals for data processing to obtain the absolute position of the motor shaft. This not only improves the resolution of the magnetic encoder but also provides better accuracy of the absolute position obtained by combining multiple induction signals, which helps to eliminate position feedback errors caused by mechanical installation errors. Attached Figure Description

[0015] Figure 1 A schematic diagram of a magnetic encoder according to one embodiment; Figure 2 This is a schematic diagram of the structure of a first magnet and a second magnet according to one embodiment; Figure 3 This is a schematic diagram of another structure of a magnetic encoder according to one embodiment; Figure 4 This is a schematic diagram of the mounting section in one embodiment; Explanation of reference numerals in the attached figures: 1-First magnet; 2-Second magnet; 3-First magnetic induction sensor; 4-Magnetic induction sensor; 5-Circuit board; 6-Mounting part; 7-Support; 701-Magnetic support part; 702-Connecting part; 703-First groove; 704-Second groove; 705-Shaft hole; 706-Threaded hole; 707-Vent hole; 8-Bracket; 801-Accommodation cavity. Detailed Implementation

[0016] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments. Similar elements in different embodiments are referred to by related similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of the present application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to the present application are not shown or described in the specification. This is to avoid obscuring the core parts of the present application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0017] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0018] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0019] The magnetic encoder contains a magnetic induction sensor to sense changes in the direction and intensity of the magnetic field of the code disk, converting them into measurable electrical signals. These signals are then conditioned by the main chip's subsequent processing circuitry to generate position feedback information ranging from 0 to 360 degrees. However, mechanical installation errors exist during the production and assembly of the magnetic code disk. Among these, the two errors that have the greatest impact on position feedback accuracy are coaxiality error and perpendicularity error.

[0020] Coaxiality error refers to the misalignment between the rotation center of the magnetic code disk and the design center of the magnetic pattern on the code disk. Perpendicularity error refers to the non-perpendicularity between the plane of the magnetic code disk and the axis of rotation. Coaxiality error causes periodic changes in the alignment between the magnetic induction sensor and the corresponding magnetized pattern, while perpendicularity error causes periodic changes in the gap between the magnetic induction sensor and the code disk. These errors result in periodic variations in the position information output by the encoder, leading to errors in the position feedback of the magnetic encoder.

[0021] To address these issues, one approach is to compare the target encoder with a high-precision reference encoder, generate a calibration table, and write it into the target encoder's memory. The encoder's output is then calibrated by looking up the table during subsequent operation. However, generating the calibration table from the reference encoder is time-consuming, and the target encoder's limited storage space restricts the accuracy of the calibration table. Furthermore, if the system error repeatability is poor, or if the radial or vertical error of the shaft changes due to factors such as aging, the previously generated error calibration table will become invalid.

[0022] Another approach is to use a self-calibration algorithm. The core of this method is to rotate the target encoder at a constant speed and then sample the encoder signal at equal time intervals. Because the sampling time is the same, encoder errors can be extracted by comparing the incremental changes in the encoder angle feedback within each fixed cycle. However, this method relies on the absolute stability of the target encoder's rotational speed under calibration conditions, which is very difficult to maintain in practical applications.

[0023] In view of this, this application includes a first magnet and a second magnet for fixing to the motor shaft. A first magnetic induction sensor is used to sense changes in the magnetic field of the first magnet to obtain a first induction signal, and at least two second magnetic induction sensors are used to sense changes in the magnetic field of the second magnet to obtain multiple second induction signals. The main chip combines the received first induction signals and multiple second induction signals for data processing to obtain the absolute position of the motor shaft. This not only improves the resolution of the magnetic encoder, but also provides better accuracy of the absolute position obtained by combining multiple induction signals, which helps to eliminate position feedback errors caused by mechanical installation errors.

[0024] The following describes some embodiments of the magnetic encoder and motor provided in this application with reference to the accompanying drawings.

[0025] Please see Figures 1 to 4 This application provides a magnetic encoder, including a magnetic component, a first magnetic induction sensor 3, at least two second magnetic induction sensors 4, and other functional components as needed, which are described in detail below.

[0026] The magnetic component in this embodiment includes a first magnet 1 and a second magnet 2 fixed to the motor shaft. The first magnet 1 has a pair of magnetic poles, and the second magnet 2 is arranged around the first magnet 1. The second magnet 2 has multiple pairs of magnetic poles arranged in a circle, and the first magnet 1 is located at the center of the circle. A first magnetic induction sensor 3 corresponds to the first magnet 1 and is used to sense the change in the magnetic field of the first magnet 1 to obtain a first induction signal. Each second magnetic induction sensor 4 is the same and is used to sense the change in the magnetic field of the second magnet 2 to obtain multiple second induction signals. A main chip is provided on the circuit board 5. The main chip is electrically connected to the first magnetic induction sensor 3 and the second magnetic induction sensor 4 and is used to process the received first induction signal and multiple second induction signals.

[0027] It is understood that in this embodiment, the first magnet 1 has a pair of magnetic poles, each pair having an N pole and a S pole; the N pole and S pole have equal magnetic magnitudes and opposite polarities, and are symmetrically distributed. The second magnet 2 can magnetize multiple N poles and S poles one by one along the circumference, thereby forming multiple pairs of magnetic poles arranged in a circle. The first magnet 1 and the second magnet 2 are fixed on the motor shaft and can rotate together with the motor shaft. The rotation of the first magnet 1 and the second magnet 2 generates a rotating magnetic field.

[0028] In this embodiment, the first magnetic induction sensor 3 senses the change in the magnetic field of the first magnet 1 and converts it into an electrical signal, thus forming a first induction signal. Similarly, each second magnetic induction sensor 4 senses the change in the magnetic field of the second magnet 2 and converts it into an electrical signal, thus forming a second induction signal. All the second magnetic induction sensors 4 in this embodiment are identical, meaning they are of the same model. Excluding installation and manufacturing errors, the identical input of each second magnetic induction sensor 4 enables the same output, thereby facilitating the fusion of multiple second induction signals.

[0029] In this embodiment, the main chip can receive and process a first sensing signal and multiple second sensing signals. Those skilled in the art can select the appropriate main chip according to the set signal processing requirements.

[0030] The magnetic encoder in the above embodiment includes a first magnet 1 and a second magnet 2 for fixing to the motor shaft. A first magnetic induction sensor 3 is used to sense the magnetic field change of the first magnet 1 to obtain a first induction signal. At least two second magnetic induction sensors 4 are used to sense the magnetic field change of the second magnet 2 to obtain multiple second induction signals. The main chip combines the received first induction signal and multiple second induction signals to perform data processing to obtain the absolute position of the motor shaft.

[0031] This not only improves the resolution of the magnetic encoder, but also enhances the accuracy of the absolute position obtained by combining multiple sensing signals, thus helping to eliminate position feedback errors caused by mechanical installation errors.

[0032] In one embodiment, such as Figure 1 , Figure 2 As shown, the magnetic encoder includes two second magnetic induction sensors 4, which are symmetrically arranged on opposite sides of the second magnet 2. The two second magnetic induction sensors 4 can acquire two second induction signals, which is beneficial for obtaining a more accurate absolute position. Furthermore, the two second magnetic induction sensors 4 are inexpensive, thus reducing manufacturing costs.

[0033] Two second magnetic induction sensors 4 are symmetrically arranged on opposite sides of the second magnet 2, that is, the two second magnetic induction sensors 4 are arranged at 180 degrees on the circumference. The position feedback error obtained through the two second magnetic induction sensors 4 can be expressed as follows:

[0034]

[0035] Where a1 and a2 represent the error magnitudes. This refers to the harmonic error angle offset.

[0036] Since the parameters of the two second magnetic induction sensors 4 are exactly the same, a1 = a2, neglecting manufacturing errors. Because the two second magnetic induction sensors 4 are geometrically 180 degrees apart, a harmonic offset relationship exists; substituting this, we get:

[0037]

[0038] Based on the relationship between E1 and E2 above, the encoder position feedback error caused by mechanical installation errors can be eliminated through calculation. The encoder accuracy can be significantly improved without comparing it to a high-precision reference encoder. Furthermore, since the two second magnetic induction sensors 4 are fixed on the same circumference, even if installation errors worsen during subsequent use, the encoder accuracy will not deteriorate.

[0039] In one embodiment, the magnetic encoder may also be provided with three second magnetic induction sensors 4, which are evenly distributed around the circumference; or, three second magnetic induction sensors 4 may be provided, with two second magnetic induction sensors 4 symmetrically arranged on opposite sides of the second magnet 2, and the three second magnetic induction sensors 4 located on the same circumference; or, four second magnetic induction sensors 4 may be provided, which are located on the same circumference, with two second magnetic induction sensors 4 distributed on one diameter line of the second magnet 2, and the other two second magnetic induction sensors 4 distributed on the other diameter line of the second magnet 2.

[0040] It is understandable that the more second magnetic induction sensors 4 there are, the better it is to eliminate mechanical installation errors. However, the more there are, the higher the cost will be. Therefore, it is preferable to set 2, 3 or 4 second magnetic induction sensors 4.

[0041] In one embodiment, such as Figure 2 As shown, the first magnet 1 is disc-shaped or ring-shaped, and the second magnet 2 has multiple pairs of magnetic poles evenly arranged in a circle to form a ring-shaped second magnet 2. When the first magnet 1 is disc-shaped, its N pole and S pole are semi-circular; when the first magnet 1 is ring-shaped, its N pole and S pole are arc-shaped. The second magnet 2 is ring-shaped, and its N pole and S pole are evenly distributed in a circle, with the N pole and S pole arranged alternately along the circumference.

[0042] The second magnetic induction sensor 4 can be a magnetoresistive sensor, so that one rotation of a pair of magnetic poles can output two cycles of raw signal. Multiple pairs of magnetic poles can generate raw signal with twice the number of cycles as the number of magnetic pole pairs. It can be understood that the more magnetic pole pairs, the higher the encoder resolution, which is beneficial for improving the encoder's accuracy and response speed. In one embodiment, the second magnet 2 can have 8, 12, or 16 pairs of magnetic poles, but it is not limited to these. More than 16 pairs of magnetic poles can also be provided. In some application scenarios, the second magnet 2 can be configured as follows: Figure 2 The 16 pairs of magnetic poles shown.

[0043] In one embodiment, such as Figure 1 , Figure 3 , Figure 4 As shown, the magnetic encoder also includes a support member 7, which includes a magnetic support portion 701 and a connecting portion 702 connected to one end of the magnetic support portion 701. A first groove 703 and a second groove 704 are provided on the side of the magnetic support portion 701 away from the connecting portion 702. The first groove 703 is located in the middle of the magnetic support portion 701 and is used to install a first magnet 1. The second groove 704 is located on the outer periphery of the magnetic support portion 701 and is used to install a second magnet 2. The connecting portion 702 is used to fix and connect with the motor shaft.

[0044] Thus, the first magnet 1 and the second magnet 2 can be fixed on the motor shaft by the support member 7, allowing the first magnet 1 and the second magnet 2 to rotate together with the motor shaft. In this embodiment, the support member 7 can be made of a non-magnetic material, such as aluminum alloy or copper alloy, and the non-magnetic material has a magnetic isolation effect.

[0045] In this embodiment, the shape of the first groove 703 can match the shape of the first magnet 1, and the shape of the second groove 704 can match the shape of the second magnet 2. The second groove 704 can be provided at the outermost periphery of the magnet support portion 701, that is, one side of the second groove 704 in the width direction extends to the side wall of the magnet support portion 701, so that the second groove 704 has only one side wall, and the processing of the second groove 704 is simple.

[0046] In some embodiments, the first magnet 1 and the second magnet 2 can be fixed in the corresponding groove by adhesive or interference fit. When the interference fit is used, the bottom of the first groove 703 can also be provided with a vent hole 707 that communicates with the outside in order to facilitate assembly.

[0047] In this embodiment, the magnetic support portion 701 and the connecting portion 702 can be combined to form a stepped shaft-shaped support member 7. This embodiment does not limit the specific fixing method between the connecting portion 702 and the motor shaft. For example, the connecting portion 702 can have a shaft hole 705 and a threaded hole 706 extending from the outer side wall of the connecting portion 702 to the shaft hole 705. The end of the motor shaft is inserted into the shaft hole 705 on the connecting portion 702, and a screw is fitted into the threaded hole 706. By tightening the screw, the motor shaft is pressed and fixed, forming a connection between the connecting portion 702 and the motor shaft.

[0048] In some applications, a blind hole can be provided at the end of the motor shaft, and the connecting part 702 can be inserted into the blind hole as a whole. This can reduce the area occupied by the support member 7 on the outer circumference of the motor shaft, and the support member 7 can be installed without extending the length of the motor shaft, which is beneficial to reducing the axial length of the motor.

[0049] In one embodiment, such as Figure 1 , Figure 3 As shown, the sides of the first magnet 1 and the second magnet 2 away from the connecting part 702 are flush with the side of the magnetic support part 701 away from the connecting part 702. At this time, the first magnet 1 and the second magnet 2 are completely embedded in the support member 7, the magnets are fixed in the support member 7, and the first magnet 1 and the second magnet 2 do not protrude from the surface of the magnetic support part 701, which helps to reduce the axial length of the motor.

[0050] In some embodiments, the sides of the first magnet 1 and the second magnet 2 that are away from the connecting portion 702 may be lower than the side of the magnetic support portion 701 that is away from the connecting portion 702, or the sides of the first magnet 1 and the second magnet 2 that are away from the connecting portion 702 may be higher than the side of the magnetic support portion 701 that is away from the connecting portion 702.

[0051] In one embodiment, such as Figure 1 , Figure 3 As shown, it also includes a bracket 8, a circuit board 5 connected to one end of the bracket 8, a first magnetic induction sensor 3 and multiple second magnetic induction sensors 4 are fixed on the circuit board 5, the bracket 8 is provided with a receiving cavity 801, and a support member 7 is used to be placed in the receiving cavity 801 so that the first magnet 1 corresponds to the first magnetic induction sensor 3 and the second magnet 2 corresponds to the second magnetic induction sensor 4.

[0052] The support member 7 is located within the accommodating cavity 801, which helps to reduce the overall axial length of the motor after assembly. In some embodiments, the support member 7 may be completely located within the accommodating cavity 801, and the magnetic induction sensor may be disposed on the side of the circuit board 5 near the support member 7.

[0053] In this embodiment, the bracket 8 can be fixed to the end cover of the motor, and one end of the motor shaft can also be supported on the end cover by a bearing. During assembly, the circuit board 5, bracket 8, and end cover can be fixed together with screws, which helps to reduce assembly steps and assembly errors.

[0054] In one embodiment, such as Figure 1 , Figure 2 As shown, the second magnetic induction sensor 4 is located at the end of the first magnet 1 closest to the circuit board 5. This helps to reduce the space occupied by the second magnetic induction sensor 4 and facilitates miniaturization.

[0055] In some implementations, such as Figure 3 As shown, the circuit board 5 may have at least two mounting portions 6 on the side near the second magnet 2. The mounting portion 6 is L-shaped, with one straight arm of the L-shape connected to the circuit board 5 and a second magnetic induction sensor 4 correspondingly disposed on the other straight arm. The mounting portion 6 is located on the outer periphery of the second magnet 2 so that the second magnetic induction sensor 4 corresponds to the outer periphery sidewall of the second magnet 2.

[0056] In this embodiment, the mounting part 6 can be, but is not limited to, a PCB board. The mounting part 6 can be an integral L-shaped structure or an L-shaped structure formed by connecting two PCB boards. The L-shaped mounting part 6 facilitates the assembly of the second magnetic induction sensor 4, provides better support for the second magnetic induction sensor 4, and helps maintain the stable position of the second magnetic induction sensor 4. In this embodiment, a gap is left between the second magnetic induction sensor 4 and the outer peripheral sidewall of the second magnet 2. With this arrangement, because the magnetic field on the outer peripheral side of the second magnet 2 is uniform, the second magnetic induction sensor 4 receives a better signal, which is more conducive to measurement.

[0057] In some embodiments, the second magnetic induction sensor 4 may be located at one end of the second magnet 2 near the circuit board 5, with a gap between the second magnetic induction sensor 4 and the end face of the second magnet 2.

[0058] The magnetic encoder provided in the above embodiment includes a first magnet 1 and a second magnet 2 for fixing to the motor shaft. A first magnetic induction sensor 3 is used to sense changes in the magnetic field of the first magnet 1 to obtain a first induction signal. At least two second magnetic induction sensors 4 are used to sense changes in the magnetic field of the second magnet 2 to obtain multiple second induction signals. The main chip combines the received first induction signal and multiple second induction signals for data processing to obtain the absolute position of the motor shaft. This not only improves the resolution of the magnetic encoder, but also provides better accuracy of the absolute position obtained by combining multiple induction signals, which helps to eliminate position feedback errors caused by mechanical installation errors.

[0059] This application embodiment also provides a motor, including a motor shaft and a magnetic encoder as described above, wherein the first magnet 1 and the second magnet 2 are both fixed to the motor shaft.

[0060] The magnetic rotary encoder in this embodiment is the same as that in the above embodiment, and will not be described again here. The first magnet 1 and the second magnet 2 can be fixed to the motor shaft by the support member 7, and one end of the motor shaft can be supported on the motor end cover by a bearing. The magnetic rotary encoder may include a bracket 8 and a circuit board 5 fixed on the bracket 8. A first magnetic induction sensor 3 and multiple second magnetic induction sensors 4 are disposed on the circuit board 5. During assembly, screws can be passed through the circuit board 5, bracket 8, and end cover in sequence to fix the circuit board 5, bracket 8, and end cover together. After assembly, the first magnetic induction sensor 3 corresponds to the first magnet 1, and the multiple second magnetic induction sensors 4 correspond to the second magnet 2. When the motor shaft rotates, the first magnet 1 and the second magnet 2 also rotate together. The precise absolute position of the motor shaft, with errors eliminated, can be obtained through the sensing measurement of the magnetic rotary encoder. The motor in this embodiment can be applied to, but is not limited to, servo systems, machine tools, robots, and other equipment.

[0061] The motor provided in the above embodiment includes a first magnet 1 and a second magnet 2 for fixing to the motor shaft. A first magnetic induction sensor 3 is used to sense changes in the magnetic field of the first magnet 1 to obtain a first induction signal. At least two second magnetic induction sensors 4 are used to sense changes in the magnetic field of the second magnet 2 to obtain multiple second induction signals. The main chip combines the received first induction signal and multiple second induction signals for data processing to obtain the absolute position of the motor shaft. This not only improves the resolution of the magnetic encoder, but also provides better accuracy of the absolute position obtained by combining multiple induction signals, which helps to eliminate position feedback errors caused by mechanical installation errors.

[0062] The above examples illustrate this application only to aid understanding and are not intended to limit its scope. Those skilled in the art to which this application pertains can make various simple deductions, modifications, or substitutions based on the ideas presented.

Claims

1. A magnetic encoder, characterized by include: A magnetic component includes a first magnet and a second magnet fixed to a motor shaft. The first magnet has a pair of magnetic poles, and the second magnet is disposed around the first magnet. The second magnet has multiple pairs of magnetic poles arranged in a circular pattern, and the first magnet is located at the center of the circumference. A first magnetic induction sensor, which corresponds to the first magnet, is used to sense changes in the magnetic field of the first magnet to obtain a first induction signal. At least two second magnetic induction sensors, and each second magnetic induction sensor is identical, are used to sense changes in the magnetic field of the second magnet to obtain multiple second induction signals; as well as A circuit board with a main chip on it, the main chip being electrically connected to the first magnetic induction sensor and the second magnetic induction sensor, for processing the received first induction signal and multiple second induction signals.

2. The magnetic encoder as described in claim 1, characterized in that, The magnetic encoder includes two second magnetic induction sensors, which are symmetrically arranged on opposite sides of the second magnet.

3. The magnetic encoder as described in claim 1, characterized in that, The magnetic encoder includes three second magnetic induction sensors, which are evenly distributed in a circular pattern. Alternatively, it may include three second magnetic induction sensors, wherein two second magnetic induction sensors are symmetrically arranged on opposite sides of the second magnet, and the three second magnetic induction sensors are located on the same circumference; Alternatively, it may include four second magnetic induction sensors located on the same circumference, with two of the second magnetic induction sensors distributed along one diameter line of the second magnet and the other two distributed along another diameter line of the second magnet.

4. The magnetic encoder as described in any one of claims 1-3, characterized in that, The first magnet is disc-shaped or ring-shaped, and the second magnet has multiple pairs of magnetic poles evenly arranged in a circle to form a ring-shaped second magnet.

5. The magnetic encoder as described in any one of claims 1-3, characterized in that, The magnetic encoder further includes a support member, which includes a magnetic support portion and a connecting portion connected to one end of the magnetic support portion. The magnetic support portion has a first groove and a second groove on the side away from the connecting portion. The first groove is located in the middle of the magnetic support portion and is used to install the first magnet. The second groove is located on the outer periphery of the magnetic support portion and is used to install the second magnet. The connecting portion is used to fix and connect with the motor shaft.

6. The magnetic encoder as described in claim 5, characterized in that, The sides of the first magnet and the second magnet that are away from the connecting portion are flush with the side of the magnetic support that is away from the connecting portion.

7. The magnetic encoder as described in claim 5, characterized in that, It also includes a bracket, the circuit board is connected to one end of the bracket, the first magnetic induction sensor and a plurality of second magnetic induction sensors are fixed on the circuit board, the bracket has a receiving cavity, and the support member is used to be placed into the receiving cavity so that the first magnet corresponds to the first magnetic induction sensor and the second magnet corresponds to the second magnetic induction sensor.

8. The magnetic encoder as described in claim 7, characterized in that, The second magnetic sensor is located at one end of the first magnet closer to the circuit board; Alternatively, the circuit board may have at least two mounting portions on the side near the second magnet. The mounting portions are L-shaped, with one straight arm connected to the circuit board and a second magnetic induction sensor correspondingly disposed on the other straight arm. The mounting portions are located on the outer periphery of the second magnet so that the second magnetic induction sensor corresponds to the outer periphery sidewall of the second magnet.

9. The magnetic encoder as described in any one of claims 1-3, characterized in that, The second magnet has 8, 12, or 16 pairs of magnetic poles.

10. An electric motor, characterized in that, It includes a motor shaft and a magnetic encoder as described in any one of claims 1-9, wherein both the first magnet and the second magnet are fixed to the motor shaft.

Images