An eddy current sensor and motor

Abstract

The present application provides an eddy current sensor and motor, comprising: a sensor probe coil and a sensor housing, one side of the sensor housing is recessed inward to form a mounting groove, the sensor probe coil can be set on the bottom surface of the mounting groove, the outer diameter R1 of the mounting groove, the groove depth H1, the axial length H0 and the outer diameter R0 of the sensor probe coil are set to satisfy a certain relationship, and z0=0~10e^5, A 01 =0.4~0.6, B 01 =0.8~1.2, B 02 =-0.1~0.1, C 02 =-0.1~0.1, A1=0.4~0.6, A2=-0.1~0.1, B1=0.8~1.2, B2=-0.1~0.1, C2=-0.1~0.1. According to the present application, the interference of the metal shell on the sensor probe can be effectively avoided, the effective range is maximized, the size of the sensor shell is not too large, and the advantages of range and volume are effectively balanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of sensor technology, in particular to an eddy current sensor and motor. BACKGROUND

[0002] Sensor is a tool for information acquisition, is the "five senses" of the machine, and is one of the three pillars of information technology. Sensor technology is the source technology of the chain of "acquisition-processing-transmission" of information, and is the basic technology of modern industrial production and automation and intelligentization, and its development level represents the industrialization level of a country. Any running machine needs displacement sensor to measure and control as long as there is movement or mechanical deformation. In addition, many non-displacement quantities, such as speed, pressure, angle, angular velocity and even torque, can be converted into displacement for measurement. Displacement sensor is the most important and basic member in the sensor family, and has a variety of types and forms to meet the needs of various application occasions. With the development of modern advanced manufacturing technology and industrial automation, higher and higher requirements are put forward for displacement sensors, such as non-contact, high resolution, high stability, high speed (wide bandwidth), low cost, small size, and high tolerance to environmental parameters and harsh environment.

[0003] The eddy current measurement principle belongs to an inductive measurement principle. Eddy current effect is derived from the energy of an oscillation circuit. Eddy current can only be formed in a conductive material. An alternating current is introduced into the coil in the sensor probe, which can form a magnetic field around the probe coil. If a conductor is placed in this magnetic field, according to Faraday's law of electromagnetic induction, eddy current will be excited in the conductor. According to Lenz's law, the magnetic field direction of eddy current is exactly opposite to that of the coil, which will change the impedance value of the coil in the probe. The change of the impedance value is directly related to the distance between the coil and the measured object. After the sensor probe is connected to the controller, the controller can obtain the change of the voltage value from the sensor probe, and calculate the corresponding distance value based on it. Eddy current measurement principle can measure all conductive materials. Since eddy current can penetrate through insulators, even if the metal material is covered with an insulator on the surface, it can also be used as the measured object of the eddy current sensor. The unique coil winding design can achieve extremely compact sensor shape while meeting the requirements of operating in high temperature measurement environment.

[0004] Eddy current probes are divided into shielded probes and unshielded probes. For shielded probes, the magnetic lines of force are more concentrated due to the use of isolation layer, which makes them relatively insensitive to the side metal of the installation position. For unshielded probes, the magnetic lines of force are more dispersed without the use of isolation layer, which makes their range larger than that of shielded sensors.

[0005] Meanwhile, correct installation is extremely important for measuring signal quality, and the size of metal near the probe will affect the linear deviation of the eddy current sensor. Ideally, if a non-shielded probe is used, there should be no metal within 3 times the diameter of the probe, that is, the installation hole should be no less than 3 times the diameter of the probe. After meeting the above conditions, almost all magnetic lines will be emitted from the probe, reach the measured object, penetrate the surface of the measured object, and generate eddy current, so only little linear deviation will be generated; if a shielded probe is used, there is no special requirement for the installation hole diameter; compared with the shielded probe, the non-shielded probe has a large range but higher installation requirements and needs a larger space.

[0006] Since the shielded eddy current probe in the prior art has a small range, and the non-shielded eddy current probe has a large installation space when a large range is ensured, the volume of the metal shell is large, the space utilization is low, and the technical problems that the range and the volume cannot be considered simultaneously cannot be solved, the present application researches and designs an eddy current sensor and a motor. SUMMARY

[0007] Therefore, the technical problem to be solved by the present application is to overcome the defects that the shielded eddy current probe in the prior art has a small range, the non-shielded eddy current probe has a large installation space when a large range is ensured, the space utilization is low, and the eddy current probe cannot consider the range and the volume simultaneously, so as to provide an eddy current sensor and a motor.

[0008] In order to solve the above problems, the present application provides an eddy current sensor, which comprises:

[0009] A sensor probe coil and a sensor shell, one side surface of the sensor shell is recessed inward to form a mounting groove, the sensor probe coil can be arranged on the bottom surface of the mounting groove, the mounting groove has a first central axis and is in a rotary body structure, the groove depth of the mounting groove in the direction of the first central axis is H1, the diameter of the opening of the mounting groove in the cross section perpendicular to the direction of the first central axis is R1, the sensor probe coil also has a second central axis and is in a rotary body structure, the second central axis is parallel to or coincides with the first central axis, the axial length of the sensor probe coil in the direction of the second central axis is H0, the outer diameter of the sensor probe coil in the cross section perpendicular to the direction of the second central axis is R0, and the following conditions are met:

[0010]

[0011] wherein L is the inductance value of the probe coil when the maximum range of the sensor probe coil is ensured by adjusting the distance between the sensor probe coil and the measured object, z0, A 01 , B 01 , B 02 , C 02A1, B1, A2, B2 and C2 are constants, and have z0 = 0 ~ 10e^5, A 01 = 0.4 ~ 0.6, B 01 = 0.8 ~ 1.2, B 02 = -0.1 ~ 0.1, C 02 = -0.1 ~ 0.1, A1 = 0.4 ~ 0.6, A2 = -0.1 ~ 0.1, B1 = 0.8 ~ 1.2, B2 = -0.1 ~ 0.1, C2 = -0.1 ~ 0.1.

[0012] In some embodiments,

[0013] R1 / R0 = 2.0 ~ 3.0, H1 / H0 = 3.0 ~ 4.0, and R1 / H1 = 3.0 ~ 5.0.

[0014] In some embodiments,

[0015] The sensor probe bracket is also a rotary body structure, the central axis of which coincides with the second central axis of the sensor probe coil, the outer diameter of the sensor probe bracket is R2, and R0 < R2 < R1, the length of the sensor probe bracket in the axial direction is H2, and H0 < H2 < H1.

[0016] In some embodiments,

[0017] The end of the sensor probe bracket fixed with the mounting groove is inserted into the inside of the bottom surface by a preset distance greater than 0.

[0018] In some embodiments,

[0019] The sensor probe bracket is also a rotary body structure, the central axis of which coincides with the second central axis of the sensor probe coil, the outer diameter of the sensor probe bracket is R2, and R0 < R2 < R1, the length of the sensor probe bracket in the axial direction is H2, and H0 < H2 < H1.

[0020] In some embodiments,

[0021] The sensor probe bracket is also a rotary body structure, the central axis of which coincides with the second central axis of the sensor probe coil, the outer diameter of the sensor probe bracket is R2, and R0 < R2 < R1, the length of the sensor probe bracket in the axial direction is H2, and H0 < H2 < H1.

[0022] In some embodiments,

[0023] The first central axis coincides with the second central axis, the sensor probe coil is a cylindrical structure, and the height of the end of the sensor probe coil away from the groove bottom of the mounting groove is less than or equal to the height of the top end of the mounting groove.

[0024] In some embodiments,

[0025] The installation groove is a cylindrical groove structure, the groove bottom of the installation groove is an axial end surface of the cylindrical groove, the sensor probe coil is installed to the groove bottom of the cylindrical groove, and cross-sectional areas of the installation groove perpendicular to the first central axis gradually increase from the groove bottom of the cylindrical groove to an opening of the cylindrical groove.

[0026] In some embodiments,

[0027] The installation groove is a circular truncated cone groove structure, the groove bottom of the installation groove is an axial end surface of the circular truncated cone groove with a relatively small area, the sensor probe coil is installed to the groove bottom of the circular truncated cone groove, and cross-sectional areas of the installation groove perpendicular to the first central axis gradually increase from the groove bottom of the circular truncated cone groove to an opening of the circular truncated cone groove.

[0028] In some embodiments,

[0029] The installation groove is a spherical groove structure, the groove bottom of the installation groove is a plane tangent to a position of any surface of the spherical groove, the sensor probe coil is installed to the groove bottom of the spherical groove, and cross-sectional areas of the installation groove perpendicular to the first central axis gradually increase from the groove bottom of the spherical groove to an opening of the spherical groove.

[0030] The application also provides an electric machine comprising the electric eddy current sensor.

[0031] The electric eddy current sensor and the electric machine provided by the application have the following beneficial effects:

[0032] The application sets the diameter R1 of the installation groove, the groove depth H1, the axial length H0 of the sensor probe coil and the outer diameter R0 of the sensor probe coil to satisfy the following relationship:

[0033]

[0034] Wherein L is the inductance value of the probe coil when the sensor probe coil has the maximum range by adjusting the distance between the sensor probe coil and the measured body, z0, A 01 , B 01 , B 02 , C 02 , A1, B1, A2, B2 and C2 are all constants, and z0=0~10e^5, A 01 =0.4~0.6, B 01 =0.8~1.2, B 02 =-0.1~0.1, C 02= -0.1~0.1, A1=0.4~0.6, A2=-0.1~0.1, B1=0.8~1.2, B2=-0.1~0.1, C2=-0.1~0.1, can effectively avoid the metal shell to interfere with the sensor probe, maximize the effective range, while still can retain its mechanical protection and easy to install the advantages of the sensor shell size, so as not to be too large, thereby ensuring that the non shielded eddy current probe can guarantee a large range, and can also reduce the installation space, improve the space utilization, effectively taking into account the range and volume of the advantages; the application further through R1 / R0=2.0~3.0, H1 / H0=3.0~4.0, while R1 / H1=3.0~5.0, can further increase the range of eddy current sensor, while also reducing the shell volume, further improve the effect of taking into account a large range and small volume. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is the longitudinal section view of the eddy current sensor of the embodiment 1 of the application;

[0036] Figure 2 is the longitudinal section view of the eddy current sensor of the embodiment 1 of the application;

[0037] Figure 3 is the perspective view of the main body structure of the non shielded integrated eddy current sensor of the application;

[0038] Figure 4 is the longitudinal section view of the eddy current sensor of the embodiment 2 of the application;

[0039] Figure 5 is the longitudinal section view of the eddy current sensor of the embodiment 3 of the application;

[0040] Figure 6 is the perspective view of the relationship between the inductance L and H1 / H0 and R1 / R0 of the eddy current sensor of the application.

[0041] The figure marks are:

[0042] 11, sensor probe coil; 12, sensor probe support; 4, sensor shell; 21, mounting groove; 1, sensor radial probe; 2, sensor axial probe; 3, circuit board. DETAILED DESCRIPTION

[0043] Clearly, the embodiments described are only some embodiments of the application and not all embodiments of the application. The descriptions of the at least one example embodiment are intended to be illustrative, and not to be limiting. Many variations to the example embodiments described herein will be readily appreciated by persons of ordinary skill in the art following a reading of the description of the embodiments within the application. The decisions rendered from the use of the example embodiments within the application will depend on the particular application and the exercise of discretion supported by the disclosures presented herein. Any and all variations that resolve from combinations of the features contained herein are fully intended to fall within the scope of the application.

[0044] It is to be understood that the terminology used herein is for the purpose of describing the particular embodiments only and is not intended to be limiting, as the scope of the application will be limited only by the appended claims. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0045] The relative arrangement of parts and steps, numerical expressions, and numerical values set forth in the examples are not intended to limit the scope of the application unless otherwise specifically stated. It is to be understood that the drawings are not necessarily to scale as the dimensions of the parts shown are for the purpose of providing an illustration of the application only and can not reflect the actual proportions of the application. Techniques, methods, and apparatus known to those of ordinary skill are not discussed in detail because such techniques, methods, and apparatus are considered to be part of the existing art. In all examples shown and discussed herein, any specific values are to be interpreted as illustrative only and not as a limitation. Thus, other examples of the example embodiments can have different values. It is to be noted that like numbers and letters refer to like elements throughout the several views of the drawings and any discussion of an item in one drawing is not necessarily to be further discussed in subsequent drawings.

[0046] In the description of the application, it is to be understood that the orientation or positional relationships indicated by terms such as "front", "back", "up", "down", "left", "right", "horizontal", "vertical", "top", "bottom", and the like are generally based on the orientation or positional relationships shown in the drawings, and are merely intended to facilitate the description of the application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore should not be construed as limiting the scope of protection of the application. The orientation terms "inner", "outer" refer to the inner and outer of the contour of the components themselves.

[0047] For purposes of the description hereinafter, spatially relative terms, such as "above", "below", "up", "down", "between", "within", "left", "right", "rear", "front", "upper", "lower", "horizontal", "vertical", "above", "below", "top", "bottom", "under", and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if a device described herein is inverted or rotated by 90 degrees, then the descriptions of "above", "below", "up", "down", "between", "within", "left", "right", "rear", "front", "upper", "lower", "horizontal", "vertical", "above", "below", "top", "bottom", "under", and the like are intended to encompass such orientations. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. It will also be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if a device described herein is inverted or rotated by 90 degrees, then the descriptions of "above", "below", "up", "down", "between", "within", "left", "right", "rear", "front", "upper", "lower", "horizontal", "vertical", "above", "below", "top", "bottom", "under", and the like are intended to encompass such orientations. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0048] In addition, it should be noted that the use of "first", "second", and the like, terminology to describe various components is merely used for convenience and does not limit the scope of the present application, unless otherwise stated, and is not to be construed as specific with respect to the scope of the present application.

[0049] As shown in the accompanying drawings, Figures 1-6 The present application provides an eddy current sensor (preferably a shielded eddy current sensor, and more preferably an integrated eddy current displacement sensor), which comprises:

[0050] The sensor probe coil 11 and the sensor housing 4 (i.e. a metal housing), one side of the sensor housing 4 is recessed inward to form a mounting groove 21, the sensor probe coil 11 can be arranged on the bottom surface of the mounting groove 21, the mounting groove 21 is a rotary body structure, has a first central axis, the groove depth of the mounting groove 21 along the direction of the first central axis is H1, the diameter of the opening of the mounting groove 21 in the cross section perpendicular to the direction of the first central axis is R1, the sensor probe coil 11 is also a rotary body structure, and has a second central axis, the second central axis is parallel to or coincides with the first central axis, the axial length of the sensor probe coil 11 along the direction of the second central axis is H0, the outer diameter of the sensor probe coil 11 in the cross section perpendicular to the direction of the second central axis is R0, and satisfies:

[0051]

[0052] Wherein L is the inductance value of the probe coil when the sensor probe coil and the measured body are adjusted to the maximum range of the sensor probe coil, z0, A 01 , B 01 , B 02 , C 02, A1, B1, A2, B2 and C2 are constants, and have z0=0~10e^5 (further preferably 35.0±5.0), A 01 =0.4~0.6, B 01 =0.8~1.2, B 02 =-0.1~0.1, C 02 =-0.1~0.1, A1=0.4~0.6, A2=-0.1~0.1, B1=0.8~1.2, B2=-0.1~0.1, C2=-0.1~0.1.

[0053] The present application sets the diameter R1 of the installation groove, the groove depth H1, the axial length H0 of the sensor probe coil and the outer diameter R0 to meet the relationship:

[0054]

[0055] Wherein L is the inductance value of the probe coil when the sensor probe coil and the measured body are adjusted to the maximum range, z0, A 01 , B 01 , B 02 , C 02 , A1, B1, A2, B2 and C2 are constants, and have z0=0~10e^5, A 01 =0.4~0.6, B 01 =0.8~1.2, B 02 =-0.1~0.1, C 02 =-0.1~0.1, A1=0.4~0.6, A2=-0.1~0.1, B1=0.8~1.2, B2=-0.1~0.1, C2=-0.1~0.1, which can effectively avoid the interference of the metal shell on the sensor probe, maximize the effective range, while still retaining its mechanical protection and the advantage of easy installation, ensuring that the size of the sensor shell is not too large, thereby ensuring the large range of the non-shielded eddy current probe, and also reducing the installation space, improving space utilization, effectively balancing the advantages of range and volume.

[0056] The present application proposes a new non-shielded integrated sensor, which has smaller installation size and higher reliability under the premise of ensuring the range. The metal shell can avoid weakening the magnetic field of the sensor probe, and the range is larger. Compared with the conventional eddy current sensor probe, the space utilization is high and the process is good. That is, while effectively avoiding the weakening of the magnetic field of the sensor probe by the metal shell (to ensure the range), the size of the metal shell can also be effectively reduced, so that the space utilization is high; while the size of the metal shell is small, the range can also be effectively ensured.

[0057] The present application simultaneously solves the following two problems:

[0058] 1. The problem that the eddy current effect exists when the metal shell is too close to the sensor probe, weakening the probe magnetic field and resulting in low probe range;

[0059] 2. The problem that the conventional eddy current sensor probe mounting hole is too large, the space utilization is poor, and the protection effect is not effective.

[0060] Since the existing eddy current sensor integrated use, the metal shell can simultaneously play a mechanical protection effect and external electromagnetic signal shielding effect on the probe coil, but the metal shell itself also has an eddy current effect, which weakens the electromagnetic field of the eddy current sensor probe itself, and reduces the detection performance of the eddy current sensor such as range, sensitivity and other key parameters.

[0061] Therefore, by machining a counterbore (i.e. a mounting groove) on the metal shell and increasing the diameter of the counterbore, the weakening effect of the metal shell eddy current effect on the probe magnetic field can be effectively reduced, but a too large hole will make the metal shell unable to play a mechanical protection effect, and unable to effectively shield external electromagnetic signal interference, reducing the stability of the sensor detection signal; increasing the depth of the counterbore can optimize the magnetic field distribution range of the eddy current sensor probe and improve the output linearity of the eddy current sensor, but a too large depth will make it difficult to assemble the probe support, reducing the sensor manufacturing process.

[0062] Therefore, the diameter R1 of the mounting groove, the groove depth H1, and the axial length H0 and the outer diameter R0 of the sensor probe coil are set to satisfy the following relationship:

[0063] The weakening of the metal shell on the sensor probe magnetic field can be effectively avoided (to ensure the range), while the size of the metal shell can be effectively reduced, so that the space utilization is high; while the size of the metal shell is small, the range can be effectively ensured.

[0064] In some embodiments,

[0065] R1 / R0 = 2.0-3.0, H1 / H0 = 3.0-4.0, and R1 / H1 = 3.0-5.0.

[0066] The present application further increases the range of the eddy current sensor, reduces the shell volume, and improves the effect of considering a large range and small volume by R1 / R0=2.0-3.0, H1 / H0=3.0-4.0, and R1 / H1=3.0-5.0. The present application further preferably sets the optimal shape of the counterbore (mounting groove) as a cylindrical hole, the optimal counterbore diameter is 2-3 times the outer diameter of the probe coil, the optimal counterbore depth is 3-4 times the thickness of the probe coil, and the optimal counterbore diameter is 3-5 times the counterbore depth. This scheme can further effectively avoid the interference of the metal shell on the sensor probe to improve the effective range, while still retaining the advantages of mechanical protection and easy installation.

[0067] In some embodiments,

[0068] The sensor probe bracket 12 is further included, the sensor probe coil 11 is mounted to the bottom surface of the mounting groove 21 through the sensor probe bracket 12, one end of the sensor probe bracket 12 is fixed with the sensor probe coil 11, and the other end is fixed with the bottom surface of the mounting groove 21.

[0069] This is a further preferred structure of the sensor probe of the present application, which can effectively mount and fix the sensor probe coil to the bottom surface of the mounting groove of the sensor shell through the sensor probe bracket.

[0070] In some embodiments,

[0071] The end of the sensor probe bracket 12 fixed with the mounting groove 21 is inserted into the inside of the bottom surface with a preset distance greater than 0. The present application further preferably inserts the end of the sensor probe bracket fixed with the mounting groove into the inside of the bottom surface by a preset distance, which can firmly fix the sensor probe bracket to the mounting groove, thereby effectively and firmly fixing the sensor probe coil to the bottom surface of the mounting groove and improving the firmness of the fixation.

[0072] In some embodiments,

[0073] The first central axis and the second central axis both extend in the vertical direction, the sensor probe coil 11 is located at the upper end of the sensor probe bracket 12, and the lower end of the sensor probe bracket 12 is inserted below the groove bottom of the mounting groove 21 of the sensor shell 4, so that the height of the lower end of the sensor probe bracket 12 is lower than the height of the groove bottom of the mounting groove 21.

[0074] It is a further preferred structure of the present application that the first central axis of the installation slot and the second central axis of the sensor probe coil both extend in the vertical direction, so that the sensor probe coil and the sensor probe support are arranged in a top-to-bottom manner, and are jointly installed in the installation slot. The height of the lower end of the sensor probe support is lower than the height of the bottom of the installation slot, so that the sensor probe support can be effectively inserted below the bottom of the installation slot, and the sensor probe support is fixed more firmly in the installation slot.

[0075] In some embodiments,

[0076] The sensor probe support 12 is also a rotary body structure, the central axis of which coincides with the second central axis of the sensor probe coil 11. The outer diameter of the sensor probe support 12 is R2, and R0 < R2 < R1. The axial length of the sensor probe support 12 is H2 (as shown in Figure 2 , which includes the part extending below the bottom of the installation slot), and H0 < H2 < H1. It is a further preferred structure of the sensor probe support of the present application that the sensor probe support is also a rotary body structure, and preferably the central axis of the sensor probe support coincides with the second central axis of the sensor probe coil. The outer diameter of the sensor probe support is greater than the outer diameter of the sensor probe coil, which can firmly install and fix the sensor probe coil, and firmly fix the sensor probe support to the bottom of the installation slot. The axial length of the sensor probe support is greater than the axial length of the sensor probe coil, which is also to firmly fix the sensor probe coil. The axial length of the sensor probe support is less than the depth of the installation slot, which can prevent the sensor probe coil from extending above the opening of the installation slot, otherwise it will not be able to avoid the weakening of the magnetic field of the sensor probe by the metal shell, thereby further improving the range of the sensor.

[0077] In some embodiments,

[0078] The sensor includes a sensor radial probe 1, a sensor axial probe 2, and a circuit board 3. The sensor radial probe 1 and / or the sensor axial probe 2 include the sensor probe coil 11 and the sensor probe support 12 (i.e., the sensor radial probe is installed on a ring structure on the inner side in the radial direction (which belongs to the shell), and the sensor axial probe is installed on a ring structure on the outer side in the radial direction (which also belongs to the shell)).

[0079] The outer diameter of the sensor probe coil is R0; the thickness (i.e., the axial length) of the sensor probe coil is H0; the diameter of the installation hole is R1; and the depth (i.e., the axial depth) of the installation hole is H1.

[0080] The simulation results of the eddy current sensor of the present application regarding the diameter R1 of the installation hole and the depth H1 of the installation hole are shown in Figure 6 , Figure 6The middle x axis is the ratio R1 / R0 of the mounting hole diameter R1 to the sensor probe coil outer diameter R0, the y axis is the ratio H1 / H0 of the mounting hole depth H1 to the sensor probe coil thickness H0, and the z axis is the inductance value L of the probe coil when the distance between the probe coil and the measured body is the maximum range of the non-shielded coil, the larger the value, the smaller the weakening effect of the sensor shell 4 on the sensor probe, and the larger the effective range.

[0081] The curved surface characteristic equation is as follows:

[0082]

[0083] The present application is Figure 6 It can be obtained that the inductance value of the sensor probe coil 11 tends to slow down with the increase of the counterbore mounting hole diameter R1 and the mounting hole depth H1. The second-order derivative of the curved surface characteristic equation can be obtained. Preferably, when R1 / R0=2-3 and H1 / H0=3-4, the sensor range can be effectively improved, and R1 / H1=3-5 can still retain the mechanical protection effect and the advantage of easy installation of the integrated sensor metal shell.

[0084] In some embodiments,

[0085] The first central axis coincides with the second central axis, the sensor probe coil 11 is a cylindrical structure, and the height of the end of the sensor probe coil 11 away from the bottom of the mounting groove 21 is less than or equal to the height of the top end of the mounting groove 21.

[0086] This is a further preferred structure form between the mounting groove and the sensor probe coil of the present application. The central axes of the two are preferably arranged to coincide, so that the mounting groove can play a role of uniform magnetic field shield around the sensor probe coil, preventing the occurrence of conditions such as weakening of the probe magnetic field due to the metal shell, making the magnetic field distribution more uniform. The height of the end of the sensor probe coil away from the bottom of the mounting groove is less than or equal to the height of the top end of the mounting groove, which can further avoid the influence of the external metal shell and other structures on the magnetic field strength of the sensor probe coil, and the axial length of the probe coil is as long as possible, which can effectively improve the magnetic field strength and improve the range of the sensor.

[0087] Example 1, as Figure 2 In some embodiments,

[0088] The mounting groove 21 is a cylindrical groove structure, the bottom of the mounting groove 21 is an axial end face of the cylindrical groove, the sensor probe coil 11 is mounted to the bottom of the cylindrical groove, and the cross-sectional area of the mounting groove 21 perpendicular to the first central axis is equal in the direction from the bottom of the cylindrical groove to its opening.

[0089] This is the preferred structure of the probe assembly of the eddy current sensor of the present application, i.e. the mounting groove structure is formed in a cylindrical shape, and the cross-sectional area of the mounting groove is equal along the axial direction, thereby effectively shielding the sensor probe coil.

[0090] Embodiment 2, as Figure 4 In some embodiments,

[0091] The mounting groove 21 is a spherical surface groove structure, the groove bottom of the mounting groove 21 is a plane tangent to the position of any surface of the spherical surface groove, and the sensor probe coil 11 is mounted to the groove bottom of the spherical surface groove. From the groove bottom of the spherical surface groove to its opening, the cross-sectional area of the mounting groove 21 perpendicular to the first central axis gradually increases.

[0092] This is the preferred structure of Embodiment 2 of the probe assembly of the eddy current sensor of the present application, i.e. the mounting groove structure is formed in a spherical surface shape, and the cross-sectional area of the mounting groove gradually increases from the groove bottom to the opening along the axial direction, thereby effectively shielding the sensor probe coil.

[0093] Embodiment 3, as Figure 5 In some embodiments,

[0094] The mounting groove 21 is a spherical surface groove structure, the groove bottom of the mounting groove 21 is a plane tangent to the position of any surface of the spherical surface groove, and the sensor probe coil 11 is mounted to the groove bottom of the spherical surface groove. From the groove bottom of the spherical surface groove to its opening, the cross-sectional area of the mounting groove 21 perpendicular to the first central axis gradually increases.

[0095] This is the preferred structure of Embodiment 3 of the probe assembly of the eddy current sensor of the present application, i.e. the mounting groove structure is formed in a spherical surface shape, and the cross-sectional area of the mounting groove gradually increases from the groove bottom to the opening along the axial direction, thereby effectively shielding the sensor probe coil.

[0096] The present application also provides an electric motor comprising the aforementioned eddy current sensor.

[0097] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above only describes the preferred embodiments of the present application, and it should be noted that for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and variations can be made, and these improvements and variations shall be considered as the protection scope of the present application.

Claims

1. An eddy current sensor, characterized in that: include: A sensor probe coil (11) and a sensor housing (4) are provided. One side of the sensor housing (4) is recessed inward to form a mounting groove (21). The sensor probe coil (11) can be mounted on the bottom surface of the mounting groove (21). The mounting groove (21) has a rotating body structure and a first central axis. The groove depth of the mounting groove (21) along the first central axis is H1. The diameter of the opening of the mounting groove (21) in a section perpendicular to the first central axis is R1. The sensor probe coil (11) also has a rotating body structure and a second central axis. The second central axis is parallel to or coincides with the first central axis. The axial length of the sensor probe coil (11) along the second central axis is H0. The outer diameter of the sensor probe coil (11) in a section perpendicular to the second central axis is R0, and the following conditions are met: ； Where L is the inductance value of the sensor probe coil when the distance between the sensor probe coil and the object being measured is adjusted to achieve the maximum range of the sensor probe coil, z0, A 01 B 01 B 02 C 02 A1, B1, A2, B2, and C2 are all constants, and z0 = 0 ~ 10e^5. 01 =0.4~0.6, B 01 =0.8~1.2, B 02 =-0.1~0.1, C 02 =-0.1~0.1, A1=0.4~0.6, A2=-0.1~0.1, B1=0.8~1.2, B2=-0.1~0.1, C2=-0.1~0.

1.

2. The eddy current sensor according to claim 1, characterized in that: R1 / R0 = 2.0~3.0, H1 / H0 = 3.0~4.0, and R1 / H1 = 3.0~5.

0.

3. The eddy current sensor according to claim 1, characterized in that: It also includes a sensor probe bracket (12), through which the sensor probe coil (11) is mounted to the bottom surface of the mounting groove (21). One end of the sensor probe bracket (12) is fixed to the sensor probe coil (11), and the other end is fixed to the bottom surface of the mounting groove (21).

4. The eddy current sensor according to claim 3, characterized in that: The end of the sensor probe bracket (12) that is fixed to the mounting groove (21) is inserted into the interior of the bottom surface at a preset distance greater than 0.

5. The eddy current sensor according to claim 3, characterized in that: The sensor probe bracket (12) is also a rotating body structure, and its central axis coincides with the second central axis of the sensor probe coil (11). The outer diameter of the sensor probe bracket (12) is R2, and R0 < R2 < R1. The axial length of the sensor probe bracket (12) is H2, and H0 < H2 < H1.

6. The eddy current sensor according to claim 3, characterized in that: It includes a sensor radial probe (1), a sensor axial probe (2) and a circuit board (3), wherein the sensor radial probe (1) and / or the sensor axial probe (2) include the sensor probe coil (11) and the sensor probe bracket (12).

7. The eddy current sensor according to claim 1, characterized in that: The first central axis coincides with the second central axis. The sensor probe coil (11) has a cylindrical structure. The height of the end of the sensor probe coil (11) away from the bottom of the mounting groove (21) is less than or equal to the height of the top of the mounting groove (21).

8. The eddy current sensor according to claim 1, characterized in that: The mounting groove (21) is a cylindrical groove structure. The bottom of the mounting groove (21) is one end face of the cylindrical groove along its axial direction. The sensor probe coil (11) is installed on the bottom of the cylindrical groove. From the bottom of the cylindrical groove to its opening, the cross-sectional area of ​​the mounting groove (21) perpendicular to the first central axis is equal.

9. The eddy current sensor according to claim 1, characterized in that: The mounting groove (21) is a frustum-shaped groove structure. The bottom of the mounting groove (21) is the axial end face of the frustum-shaped groove. The sensor probe coil (11) is installed on the bottom of the frustum-shaped groove. The bottom of the mounting groove (21) is the axial end face of the frustum-shaped groove with a relatively small area. From the bottom of the frustum-shaped groove to its opening, the cross-sectional area of ​​the mounting groove (21) perpendicular to the first central axis gradually increases.

10. The eddy current sensor according to claim 1, characterized in that: The mounting groove (21) is a spherical groove structure. The bottom of the mounting groove (21) is a plane formed by the position of any surface of the spherical groove being tangent. The sensor probe coil (11) is installed on the bottom of the spherical groove. From the bottom of the spherical groove to its opening, the cross-sectional area of ​​the mounting groove (21) perpendicular to the first central axis gradually increases.

11. An electric motor, characterized in that: The eddy current sensor included in any one of 1-10.

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