Electromagnetic induction type encoder

Abstract

The invention relates to the technical field of electromagnetic induction type encoding, in particular to an electromagnetic induction type encoder which comprises a shell, a rotating shaft, a first bearing, a rotor, a stator, a resolving plate and a compensation assembly. The rotating shaft is installed on the inner side of the shell, the first bearing is connected to the upper end of the rotating shaft, and the rotor, the stator and the resolving plate are sequentially connected to the lower side of the first bearing; the compensation assembly comprises a compensation coil, an electric push rod, a second bearing, a shaft rod, a shaft sleeve and a signal processing module, the shaft rod is installed on the inner side of the lower end of the shell, the shaft sleeve is installed on the outer side of the shaft rod and connected with the stator, and the second bearing is installed on the outer side of the shaft sleeve. The signal processing module and the compensation coil are sequentially installed at the lower end of the rotating shaft, the current in the compensation coil can be changed when the vertical distance between the compensation coil and the stator inner coil changes, and the signal processing module drives the electric push rod to push the shaft sleeve to keep the vertical distance between the stator and the compensation coil constant according to the current change.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic induction encoding, and in particular to an electromagnetic induction encoder. Background Art

[0002] An inductive encoder consists of two main parts: a stator, also known as the sensor, and a rotor, also known as the target. The stator contains a transmitter coil and two or sometimes more receiver coils, printed on a circuit board or, in some cases, directly on the stator substrate. The receiver coils are printed to generate sine and cosine waves. In many designs, electronic circuitry for signal processing is also integrated into the stator. The rotor or target is passive and made of either ferromagnetic material or a substrate containing a conductive material such as a copper layer or pattern.

[0003] When voltage is applied to the transmitter coil on the stator or sensor, an electromagnetic field is generated. When the rotor or target passes the sensor, eddy currents are generated on the target surface. These eddy currents generate an opposing magnetic field, which reduces the magnetic flux density between the sensor and the target. This causes a voltage to be generated at the receiver coil on the sensor. The amplitude and phase of the receiver voltage vary as the target moves, and the target's position can be determined based on these voltages.

[0004] However, when the internal shaft and rotor of an inductive encoder rotate at high speed, axial motion is prone to occur. This is when the motor shaft or encoder shaft moves slightly in the axial direction. This causes the distance between the rotor and stator to change, thereby affecting the magnetic flux density between the sensor and the target. This effect can lead to measurement errors and affect the accuracy and stability of the encoder. During the machining of precision parts, the tool must move precisely along a preset path. Even the slightest position deviation can render the workpiece scrapped. Existing technologies incorporate axial motion compensation algorithms into the control system, adjusting the measurement results based on the amount of axial motion. However, using algorithmic compensation to address encoder axial motion relies on accurate detection of the direction and distance of axial motion. In practical applications, various interferences and errors prevent precise detection, thus affecting the compensation effect. Furthermore, algorithmic compensation requires real-time analysis and adjustment of the encoder output. If the algorithm is computationally intensive or the processing speed is insufficient, the real-time performance of the system can be affected, resulting in reduced control accuracy.

[0005] In order to solve the above problems, an electromagnetic induction encoder is proposed. Summary of the Invention

[0006] The present invention aims to provide an electromagnetic induction encoder. By arranging a compensation component on the rotating shaft, a current is passed through the excitation coil on the stator to generate a magnetic field. When the vertical distance between the stator and the compensation component changes, the compensation coil within the compensation component generates an induced current, which pushes the stator so that the distance between the stator and the rotor remains consistent. This solves the problem of measurement errors caused by slight axial movement of the motor shaft or encoder shaft when the rotating shaft and rotor rotate at high speed in the inductive encoder.

[0007] An electromagnetic induction encoder comprises a housing, a rotating shaft, a first bearing, a rotor, a stator, a resolver board, a first power supply and a compensation assembly, wherein the first bearing is fixedly mounted on the inner side of the upper end of the housing, the rotating shaft is connected to the lower end of the bearing, the rotor, stator and resolver board are sequentially mounted on the lower side of the rotating shaft and are coaxial with the rotating shaft, the first power supply is fixedly connected to the lower end of the housing, the compensation assembly comprises a compensation coil, an electric push rod, a second bearing, a shaft, a sleeve, a signal processing module and a second power supply, the lower end of the shaft is fixedly mounted on the inner side of the lower end of the housing, the second bearing is fixedly mounted on the lower end of the rotating shaft, the sleeve is fixedly mounted on the inner side of the second bearing, a plurality of the electric push rods are connected between the rotating shaft and the upper end of the outer ring of the second bearing, the second power supply, the signal processing module and the compensation coil are sequentially fixedly mounted on the lower end of the rotating shaft, a change in the vertical distance between the compensation coil and the coil inside the stator will change the current in the compensation coil, and the signal processing module drives the electric push rod to push the sleeve according to the change in current to keep the vertical distance between the stator and the compensation coil constant. Preferably, the rotor is fixedly mounted with a first code channel and a second code channel in sequence from the inside to the outside, and a plurality of metal wires are fixedly mounted on the upper end of the rotor and electrically connected to the signal processing module, and the positions of the metal wires correspond to the positions of the second code channel, and the signal processing module controls the plurality of electric push rods individually.

[0008] In the above scheme, alternating current is passed through the excitation coil in the stator to generate a magnetic field, and the metal wire cuts the magnetic lines of force to generate an induced current. Under normal circumstances, when the rotor rotates, the induced currents in multiple metal wires are of the same magnitude. If the stator and the rotor are not parallel, the induced current in the metal wire close to the stator is larger, while the induced current in the metal wire far from the stator is smaller. At this time, the current signal in the metal wire is transmitted to the signal processing module, and the signal processing module controls the electric push rod to push forward until the current in the metal wire is consistent. At this time, the stator and the rotor remain relatively parallel to avoid errors in the signal received by the receiving coil on the stator, and the position of the metal wire corresponds to the position of the second code channel to avoid the metal wire cutting the magnetic lines of force affecting the electromagnetic induction between the metal block of the second code channel on the rotor and the stator.

[0009] Preferably, the stator is sequentially installed with a first excitation coil, a first induction coil, a second excitation coil and a second induction coil from the inside to the outside; the first induction coil and the second induction coil correspond to the vertical positions of the first code channel and the second code channel, and a heat conducting plate is fixedly installed at the bottom of the stator and fixedly connected to the shaft sleeve, and the heat conducting plate is made of non-metallic rigid material.

[0010] In the above scheme, two groups of excitation coils and two groups of induction coils are set respectively. The phase difference of the alternating current generated in the two groups of induction coils is used to determine the number of rotations, the direction of rotation and the real-time position of the rotor. The excitation coil will generate heat when energized, thereby affecting the magnetic flux density between the sensor and the target. The heat is conducted away by the heat conducting plate, thereby improving the detection accuracy of the encoder. In order to avoid the influence of the heat conducting plate on the electromagnetic induction between the stator and the rotor, a non-metallic heat conducting plate is used, and a rigid material is used to support and fix the rotor.

[0011] Preferably, a plurality of adjustment rods are fixedly mounted on the lower end of the shaft sleeve, the adjustment rods pass through the bottom end of the shell, and the plurality of adjustment rods are fixed on the adjustment plate in a circular array.

[0012] In the above solution, the electromagnetic induction encoder needs to adjust the air gap between the stator and the rotor multiple times during installation to ensure that the current signal generated by the receiving coil is clearer. Here, the adjustment rod can be directly used to push the sleeve to change the stator position to adjust the distance between the stator and the rotor, avoiding the need for repeated disassembly and assembly.

[0013] Preferably, the number of the electric push rods is the same as the number of the metal wires, and the positions correspond to the metal wires.

[0014] In the above scheme, each metal wire corresponds to the control of the electric push rod separately, which reduces the need for the signal processing module to calculate and integrate the current sizes in all metal wires to control the operation of the electric push rod, reduces the calculation time of the signal processing module, improves the response speed, and improves the operating accuracy of the encoder.

[0015] Preferably, a connection port is provided at the upper end of the rotating shaft. The connection port is made of a flexible metal material and has a rough inner surface. The diameter of the inner surface of the connection port is slightly smaller than the diameter of the motor shaft surface.

[0016] In the above solution, when the motor shaft is connected to the rotating shaft, the motor shaft can be inserted into the connecting port because the inner surface diameter of the connecting port is slightly smaller than the surface diameter of the motor shaft, which can prevent deviation caused by looseness. In addition, the use of flexible metal material for the connecting port can effectively reduce the mechanical vibration caused by the motor shaft and reduce the degree of shaft movement problems.

[0017] Preferably, a trapezoidal adjustment hole is provided on the outer side of the lower end of the connection port, an adjustment ring is slidably connected to the outer end of the trapezoidal adjustment hole, a plurality of fan blades are rotatably connected to the outer periphery of the adjustment ring, the fan blades pass through the adjustment ring, and the part passing through the adjustment ring cooperates with the trapezoidal adjustment hole, a ventilation port is provided at the lower end of the outer shell, a dust filter is connected in the ventilation port, and the dust filter is detachable.

[0018] In the above scheme, by setting fan blades, the rotation of the shaft is used to drive the air circulation inside the encoder. At the same time, the adjustment hole and the fan blades are used in combination. Regardless of whether the motor rotates forward or reverse, the wind direction can be blown from the inside to the outside, driving the internal air circulation to increase heat dissipation while effectively preventing dust from entering the encoder from the bearing.

[0019] Preferably, the solver board is provided with a groove directly connected to the first power supply, and the solver board is directly fixed to the inner side of the bottom end of the shell, and the upper surface of the solver board is made of electromagnetic shielding material.

[0020] In the above scheme, a groove is provided on the solver board that is directly connected to power supply 1, so that the wires of power supply 1 and each electrical module in the solver board can be connected from the inside of the solver board, and electromagnetic shielding material is used on the upper surface of the solver board to avoid excessive circuits from interfering with the electromagnetic induction between the stator and the rotor. At the same time, the solver board is fixed on the inner side of the bottom end of the shell to facilitate heat dissipation of the solver board.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. An electromagnetic induction encoder generates an electromagnetic field by energizing the excitation coil on the stator. The generated electromagnetic field will generate an induced current in the compensation coil fixed at the bottom of the rotating shaft. When the vertical distance between the stator and the excitation coil changes, the magnetic flux in the compensation coil will also change accordingly, causing the current in the compensation coil to change. At this time, the signal processing module receives the current change generated by the compensation coil, thereby driving the electric push rod to push the second bearing and the shaft sleeve to drive the stator to move, keeping the distance between the stator and the compensation coil unchanged. At the same time, because the compensation coil and the rotor are fixedly connected to the rotating shaft, the vertical distance between the stator and the rotor can be kept constant, solving the problem of detection signal error caused by the shaft runout problem.

[0023] 2. An electromagnetic induction encoder uses a metal wire installed on the back of the rotor and electrically connected to a signal processing module. If the stator and rotor are not parallel, the induced current in the metal wire closer to the stator is larger, while the induced current in the metal wire farther from the stator is smaller. At this time, the current signal in the metal wire is transmitted to the signal processing module, which controls the electric push rod to move forward until the current in the metal wire is consistent, at which point the stator and rotor remain relatively parallel, making the detection signal more accurate.

[0024] 3. An electromagnetic induction encoder, which limits the vertical movement of the rotor and stator by providing a second bearing and a shaft, ensures that the axes of the rotor and stator are always on a vertical axis, and ensures that the rotor and stator will not deviate in the horizontal direction. At the same time, because the shaft and the second bearing connect the rotor and stator in series into a whole, when the encoder is subjected to the vibration generated by the operation of the motor, there will be no offset between the stator and the rotor, which greatly reduces the impact of mechanical vibration on the electromagnetic induction between the rotor and stator, ensures that the rotor and stator will not deviate in the horizontal direction, and makes the detection signal more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0026] Figure 2 It is a schematic diagram of the cross-sectional structure of the present invention;

[0027] Figure 3 Schematic diagram of the internal structure of the present invention;

[0028] Figure 4 Schematic diagram of the rotor structure of the present invention;

[0029] Figure 5 Schematic diagram of the stator structure of the present invention;

[0030] Figure 6 This is a schematic diagram of the rotating shaft of the present invention;

[0031] Figure 7 This is a schematic diagram of the fan of the present invention;

[0032] Figure 8 It is a schematic diagram of the working principle of the present invention.

[0033] In the figure: 1. Housing; 11. Ventilation port; 12. Dust filter; 2. Rotating shaft; 21. Connecting port; 22. Trapezoidal adjustment hole; 23. Adjustment ring; 24. Fan blade; 3. Bearing 1; 4. Rotor; 41. First code channel; 42. Second code channel; 43. Metal wire; 5. Stator; 51. First excitation coil; 52. First induction coil; 53. Second excitation coil; 54. Second induction coil; 55. Heat conduction plate; 6. Resolver board; 61. Groove; 7. Power supply 1; 8. Compensation component; 81. Compensation coil; 82. Electric push rod; 83. Bearing 2; 84. Shaft; 841. Limit rod; 85. Bushing; 851. Adjustment rod; 852. Adjustment board; 86. Signal processing module; 87. Power supply 2. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] See also Figures 1 to 8 The present invention provides an electromagnetic induction encoder, and the technical solution is as follows:

[0036] As an embodiment of the present invention, reference Figure 2 An electromagnetic induction encoder includes a housing 1, a rotating shaft 2, a bearing 3, a rotor 4, a stator 5, a resolver 6, a power supply 7, and a compensation component 8. The rotating shaft 2 is installed at the vertical axis position inside the housing 1. The bearing 3 is fixedly connected to the upper end of the rotating shaft 2. The rotor 4, the stator 5, and the resolver 6 are fixedly connected to the lower side of the bearing 3 in sequence and are coaxial with the bearing 3. The power supply 7 is fixedly connected to the lower end of the housing 1. The compensation component 8 includes a compensation coil 81, an electric push rod 8 2. Bearing 2 83, shaft 84, sleeve 85, signal processing module 86, power supply 2 87. The lower end of the shaft 84 is fixedly mounted on the inner side of the lower end of the housing 1, and the sleeve 85 is slidably mounted on the outside of the shaft 84 and fixedly connected to the stator 5. The bearing 2 83 is fixedly mounted on the outside of the sleeve 85. Multiple electric push rods 82 are connected between the rotating shaft 2 and the upper end of the outer ring of the bearing 2 83. The power supply 2 87, signal processing module 86, and compensation coil 81 are fixedly mounted on the lower end of the rotating shaft 2 in sequence.

[0037] In this embodiment, an electromagnetic field is generated by energizing the first excitation coil 51 and the second excitation coil 53 on the stator 5. The generated electromagnetic field will generate an induced current in the compensation coil 81 fixed at the bottom end of the rotating shaft 2. When the vertical distance between the stator 5 and the first excitation coil 51 and the second excitation coil 53 changes, the magnetic flux in the compensation coil 81 will also change accordingly, thereby causing the current in the compensation coil 81 to change. At this time, the signal processing module 86 receives the current change generated by the compensation coil 81, thereby driving the electric push rod 82 to push the bearing 2 83 and the sleeve 85 to drive the stator 5 to move, keeping the distance between the stator 5 and the compensation coil 81 unchanged. At the same time, a limit rod 841 is provided on the shaft 84 to ensure that the sleeve 85 will not rotate with the bearing 2 83. Because the compensation coil 81 and the rotor 4 are fixedly connected to the rotating shaft 2, the vertical distance between the stator 5 and the rotor 4 can be kept constant, thereby solving the problem of detection signal error caused by the shaft runaway problem.

[0038] As an embodiment of the present invention, reference Figure 2 and Figure 4The rotor 4 is fixedly mounted with a first code track 41 and a second code track 42 from the inside to the outside. A plurality of metal wires 43 are fixedly mounted on the upper end of the rotor 4 and are electrically connected to the signal processing module 86. The position of the metal wires 43 corresponds to the position of the second code track 42. The signal processing module 86 controls the plurality of electric push rods 82 individually.

[0039] In this embodiment, alternating current is passed through the excitation coil in the stator 5 to generate a magnetic field, and the metal wire 43 cuts the magnetic flux lines to generate an induced current. Under normal circumstances, when the rotor 4 rotates, the induced currents in multiple metal wires 43 are of the same magnitude. If the stator 5 and the rotor 4 are not parallel, the induced current in the metal wire 43 close to the stator 5 is larger, while the induced current in the metal wire 43 far from the stator 5 is smaller. At this time, the current signal in the metal wire 43 is transmitted to the signal processing module 86, and the signal processing module 86 controls the electric push rod 82 to push forward until the current in the metal wire 43 is consistent. At this time, the stator 5 and the rotor 4 remain relatively parallel to avoid errors in the signal received by the receiving coil on the stator 5, and the position of the metal wire 43 corresponds to the position of the second code channel 42, to avoid the metal wire 43 cutting the magnetic flux lines and affecting the electromagnetic induction between the metal block of the second code channel 42 on the rotor 4 and the stator 5.

[0040] As an embodiment of the present invention, reference Figure 2 and Figure 5 The stator 5 is provided with a first excitation coil 51, a first induction coil 52, a second excitation coil 53 and a second induction coil 54 from the inside to the outside. The first induction coil 52 and the second induction coil 54 correspond to the vertical positions of the first code track 41 and the second code track 42. A heat conducting plate 55 is fixedly installed at the bottom of the stator 5 and is fixedly connected to the shaft sleeve 85. The heat conducting plate 55 is made of non-metallic rigid material.

[0041] In this embodiment, two groups of excitation coils and two groups of induction coils are respectively provided, and the phase difference of the alternating current generated in the two groups of induction coils is used to determine the number of rotations, the direction of rotation and the real-time position of the rotor 4. The excitation coils will generate heat when energized, thereby affecting the magnetic flux density between the sensor and the target. The heat is conducted away by the heat conducting plate 55, thereby improving the detection accuracy of the encoder. In order to prevent the heat conducting plate 55 from affecting the electromagnetic induction between the stator 5 and the rotor 4, a non-metallic heat conducting plate 55 is used, and a rigid material is used to support and fix the rotor 4.

[0042] As an embodiment of the present invention, reference Figure 3 A plurality of adjustment rods 851 are fixedly mounted on the lower end of the sleeve 85 . The adjustment rods 851 pass through the bottom end of the housing 1 . The plurality of adjustment rods 851 are fixed on the adjustment plate 852 in a circular array.

[0043] In this embodiment, the electromagnetic induction encoder needs to adjust the air gap between the stator 5 and the rotor 4 multiple times during installation to ensure that the current signal generated by the receiving coil is clearer. Here, the adjustment rod 851 can be directly used to push the sleeve 85 to change the position of the stator 5 to adjust the distance between the stator 5 and the rotor 4, avoiding the need for repeated disassembly and assembly.

[0044] As an embodiment of the present invention, reference Figure 2 and Figure 3 The number of the electric push rods 82 is the same as the number of the metal wires 43, and their positions correspond to the metal wires 43.

[0045] In this embodiment, each metal wire 43 corresponds to the control of the electric push rod 82 individually, which reduces the need for the signal processing module 86 to calculate and integrate the current sizes in all metal wires 43 to control the operation of the electric push rod 82, reduces the calculation time of the signal processing module 86, improves the response speed of the electric push rod 82, and improves the operating accuracy of the encoder.

[0046] As an embodiment of the present invention, reference Figure 6 A connection port 21 is provided at the upper end of the rotating shaft 2. The connection port 21 is made of flexible metal material and has a rough inner surface. The inner surface diameter of the connection port 21 is slightly smaller than the surface diameter of the motor shaft.

[0047] In this embodiment, when the motor shaft is connected to the rotating shaft 2, the motor shaft can be inserted into the connecting port 21, and the connecting port 21 is made of flexible metal material, which can effectively reduce the mechanical vibration caused by the motor shaft and reduce the degree of shaft movement problem.

[0048] As an embodiment of the present invention, reference Figure 7 A trapezoidal adjustment hole 22 is provided on the outer side of the lower end of the connecting port 21, and an adjustment ring 23 is slidably connected to the outer end of the trapezoidal adjustment hole 22. A plurality of fan blades 24 are rotatably connected to the outer periphery of the adjustment ring 23. The fan blades 24 pass through the adjustment ring 23, and the part passing through the adjustment ring 23 cooperates with the trapezoidal adjustment hole 22.

[0049] In this embodiment, by providing fan blades 24, the rotation of the shaft 2 is utilized to drive the air circulation inside the encoder. At the same time, the adjustment hole and the fan blades 24 cooperate to allow the wind to blow from the inside to the outside regardless of whether the motor rotates forward or reverse, thereby driving internal air circulation to increase heat dissipation while effectively preventing dust from entering the encoder from the bearing 3.

[0050] As an embodiment of the present invention, reference Figure 2 The solver plate 6 is provided with a groove 61 directly connected to the power supply 7, and the solver plate 6 is directly fixed to the inner side of the bottom end of the shell 1, and the upper end surface of the solver plate 6 uses electromagnetic shielding material.

[0051] In this embodiment, a groove 61 is provided on the solver board 6 to be directly connected to the power supply 7 so that the power supply 7 and the wires of each electrical module in the solver board 6 can be connected from the inside of the solver board 6, and electromagnetic shielding material is used on the upper surface of the solver board 6 to avoid excessive circuits from interfering with the electromagnetic induction between the stator 5 and the rotor 4. At the same time, the solver board 6 is fixed on the inner side of the bottom end of the shell 1 to facilitate heat dissipation of the solver board 6.

[0052] Working principle: Changes in the vertical distance between the compensation coil 81 and the coil inside the stator 5 will change the current size in the compensation coil 81. The signal processing module 86 drives the electric push rod 82 to push the shaft 84 according to the current change to keep the vertical distance between the stator 5 and the compensation coil 81 constant. A plurality of metal wires 43 are fixedly installed on the upper end of the rotor 4. If the stator 5 and the rotor 4 are not parallel, the induced current in the metal wire 43 close to the stator 5 is larger and the induced current in the metal wire 43 away from the stator 5 is smaller. At this time, the current signal in the metal wire 43 is transmitted to the signal processing module 86, and the signal processing module 86 controls the electric push rod 82 to push forward until the current in the metal wire 43 is consistent. At this time, the stator 5 and the rotor 4 remain relatively parallel, and the vertical distance remains constant, ensuring that the detection signal generated by the induction coil is not affected by the shaft runaway problem.

[0053] Specifically, the process of solving the shaft runaway problem is as follows: an electromagnetic field is generated by energizing the first excitation coil 51 and the second excitation coil 53 on the stator 5. The generated electromagnetic field will be fixed in the compensation coil 81 at the bottom end of the rotating shaft 2 to generate an induced current. When the vertical distance between the stator 5 and the first excitation coil 51 and the second excitation coil 53 changes, the magnetic flux in the compensation coil 81 will also change accordingly, thereby causing the current in the compensation coil 81 to change. At this time, the signal processing module 86 receives the current change generated by the compensation coil 81, thereby driving the electric push rod 82 to push the bearing 2 83 and the shaft sleeve 85 to drive the stator 5 to move, keeping the distance between the stator 5 and the compensation coil 81 unchanged. At the same time, because the compensation coil 81 and the rotor 4 are fixedly connected to the rotating shaft 2, the vertical distance between the stator 5 and the rotor 4 can be ensured to remain constant, thereby solving the problem of detection signal error caused by the shaft runaway problem.

[0054] The process of ensuring that the stator 5 and the rotor 4 are parallel: alternating current is passed through the excitation coil in the stator 5 to generate a magnetic field, and the metal wire 43 cuts the magnetic flux lines to generate an induced current. Under normal circumstances, the induced currents in multiple metal wires 43 are of the same magnitude when the rotor 4 rotates. If the stator 5 and the rotor 4 are not parallel, the induced current in the metal wire 43 close to the stator 5 is larger, while the induced current in the metal wire 43 far away from the stator 5 is smaller. At this time, the current signal in the metal wire 43 is transmitted to the signal processing module 86, and the signal processing module 86 controls the electric push rod 82 to push forward until the current in the metal wire 43 is consistent. At this time, the stator 5 and the rotor 4 remain relatively parallel to avoid errors in the signal received by the receiving coil on the stator 5, and the position of the metal wire 43 corresponds to the position of the second code channel 42, to avoid the metal wire 43 cutting the magnetic flux lines and affecting the electromagnetic induction between the metal block of the second code channel 42 on the rotor 4 and the stator 5.

[0055] Heat dissipation process: When the shaft 2 rotates, it drives the adjustment ring 23 to rotate. At this time, the fan blade 24 fixed on the adjustment ring 23 passes through the adjustment ring 23 and fits into one side of the trapezoidal adjustment hole 22. At this time, the fan blade 24 rotates to blow the airflow from the inside of the encoder to the outside of the encoder. When the shaft 2 reverses, the fan blade 24 passes through the adjustment ring 23 and fits into the other side of the trapezoidal adjustment hole 22. At this time, the direction of the fan blade 24 is 90 degrees different from before. At this time, the fan blade 24 rotates and still blows the airflow from the inside of the encoder to the outside of the encoder, ensuring that dust cannot enter the encoder from the connection port 21. At the same time, the dust filter 12 fixed to the vent 11 can prevent dust from entering the encoder when the encoder is working. The dust filter 12 can be disassembled and cleaned after the work is completed.

[0056] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An electromagnetic induction encoder, comprising a housing (1), a rotating shaft (2), a bearing (3), a rotor (4), a stator (5), a resolver (6), and a power supply (7), characterized in that: The invention also includes a compensation component (8), wherein the bearing 1 (3) is fixedly mounted on the inner side of the upper end of the housing (1), the rotating shaft (2) is connected to the lower end of the bearing 1 (3), the rotor (4), the stator (5), and the solver (6) are sequentially mounted on the lower side of the rotating shaft (2) and are coaxial with the rotating shaft (2), the power supply 1 (7) is fixedly connected to the lower end of the housing (1), and the compensation component (8) includes a compensation coil (81), an electric push rod (82), a bearing 2 (83), a shaft (84), a shaft sleeve (85), a signal processing module (86), and a power supply 2 (87), wherein the lower end of the shaft (84) is fixedly mounted on the inner side of the lower end of the housing (1), the bearing 2 ( 83) is fixedly installed at the lower end of the rotating shaft (2), the sleeve (85) is fixedly installed on the inner side of the second bearing (83), and a plurality of the electric push rods (82) are connected between the rotating shaft (2) and the upper end of the outer ring of the second bearing (83). The second power supply (87), the signal processing module (86), and the compensation coil (81) are fixedly installed at the lower end of the rotating shaft (2) in sequence. The change in the vertical distance between the compensation coil (81) and the inner coil of the stator (5) will change the current in the compensation coil (81). The signal processing module (86) drives the electric push rod (82) to push the sleeve (85) according to the change in current so that the vertical distance between the stator (5) and the compensation coil (81) remains constant.

2. The electromagnetic induction encoder according to claim 1, wherein: The rotor (4) is fixedly mounted with a first code track (41) and a second code track (42) in sequence from the inside to the outside. A plurality of metal wires (43) electrically connected to a signal processing module (86) are fixedly mounted on the upper end of the rotor (4), and the positions of the metal wires (43) correspond to the positions of the second code track (42). The signal processing module (86) controls the plurality of electric push rods (82) individually.

3. The electromagnetic induction encoder according to claim 2, characterized in that: The stator (5) is sequentially mounted with a first excitation coil (51), a first induction coil (52), a second excitation coil (53), and a second induction coil (54) from the inside out; the first induction coil (52) and the second induction coil (54) correspond to the vertical positions of the first code track (41) and the second code track (42), respectively. A heat conducting plate (55) is fixedly mounted on the bottom of the stator (5), and the heat conducting plate (55) is fixedly connected to the shaft sleeve (85).

4. The electromagnetic induction encoder according to claim 1, wherein: A plurality of adjustment rods (851) are fixedly mounted on the lower end of the shaft sleeve (85), the adjustment rods (851) pass through the bottom end of the housing (1), and an adjustment plate (852) is fixedly connected to the lower ends of the plurality of adjustment rods (851).

5. The electromagnetic induction encoder according to claim 2, wherein: The number of the electric push rods (82) is the same as the number of the metal wires (43), and the positions thereof correspond to the metal wires (43).

6. The electromagnetic induction encoder according to claim 1, characterized in that: A connecting port (21) is provided at the upper end of the rotating shaft (2). The connecting port (21) is made of a flexible metal material and has a rough inner surface. The inner surface diameter of the connecting port (21) is slightly smaller than the surface diameter of the motor shaft.

7. The electromagnetic induction encoder according to claim 6, characterized in that: A trapezoidal adjustment hole (22) is provided on the outer side of the lower end of the connection port (21), an adjustment ring (23) is slidably connected to the outer end of the trapezoidal adjustment hole (22), a plurality of fan blades (24) are rotatably connected to the outer periphery of the adjustment ring (23), the fan blades (24) pass through the adjustment ring (23), and the portion passing through the adjustment ring (23) is matched with the trapezoidal adjustment hole (22), a ventilation port (11) is provided on the lower end of the housing (1), a dust filter (12) is connected inside the ventilation port (11), and the dust filter (12) is detachable.

8. The electromagnetic induction encoder according to claim 1, characterized in that: The solver plate (6) is provided with a groove (61), the groove (61) is connected to the power supply (7), and the lower end of the solver plate (6) is in contact with the inner side of the bottom end of the shell (1), and the upper end surface of the solver plate (6) is made of electromagnetic shielding material.

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