A sensor assembly for rotor displacement detection and electric machine

Abstract

The application provides a rotor displacement detection sensor assembly and a motor. The rotor displacement detection sensor assembly comprises a measured rotor, a sensor probe and a compensation probe. The measured rotor comprises an axial detection position. The sensor probe is arranged at the radial outer side of the axial detection position and opposite to the axial detection position in the radial direction. The compensation probe is arranged at the radial outer side of the measured rotor and does not oppose the axial detection position. The direction along the central axis of the measured rotor is the Z-axis direction. The direction perpendicular to the Z-axis and passing through the center of the sensor probe is the X-axis direction. According to the application, the displacement signals in the X and Z directions can be output simultaneously, the detection precision is high, and the precision is high.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and more specifically to a sensor assembly and motor for rotor displacement detection. Background Technology

[0002] Sensors are tools for information acquisition, the "five senses" of machines, and one of the three pillars of information technology. Sensor technology is the source technology of the information "acquisition-processing-transmission" chain, and a fundamental technology for the automation and intelligence of modern industrial production. Its development level represents a country's level of industrialization. Any operating machinery, as long as there is motion or mechanical deformation, requires displacement sensors for measurement and control. In addition, many non-displacement quantities, such as velocity, pressure, angle, angular velocity, and even torque, can be converted into displacement for measurement. Displacement sensors are the most important and fundamental members of the sensor family, with a rich variety of types and forms to meet the needs of various applications. With the development of modern advanced manufacturing technology and industrial automation, increasingly higher requirements are placed on displacement sensors, such as non-contact operation, high resolution, high stability, high speed (wide bandwidth), low cost, small size, insensitivity to environmental parameters, and high tolerance to harsh environments.

[0003] like Figure 1 As shown in the figure, a single displacement sensor probe is typically used to detect displacement in only one direction and cannot detect displacement in the direction perpendicular to that direction. As shown in the figure, the sensor probe is installed in the X direction and can detect displacement in the X direction. However, displacement in the Y and Z directions cannot be recognized by the sensor probe installed in the X direction. If it is necessary to detect displacement in the Y and Z directions, additional sensor probes need to be installed in the corresponding directions.

[0004] In practical applications, due to space constraints and other factors, it is impossible to install sensor probes in all measured directions. However, by treating the surface of the object being measured, a single displacement sensor probe can identify displacements in multiple directions, such as... Figure 2 As shown, the object under test is a rotor. The Z direction is the axial radial direction, and the X and Y directions are the radial directions. The sensor probe is installed in the X direction and can normally detect the displacement in the X direction. By machining a step or inclined surface along the axial Z direction within the detection range of the sensor probe on the rotor under test, the sensor probe installed in the X direction can identify the displacement of the rotor under test in the Z direction, realizing the simultaneous displacement detection in two directions by a single probe.

[0005] By processing the object being measured, a single displacement sensor probe can identify multi-directional displacement. However, the probe cannot output the displacement in each direction separately. This problem is usually solved by adding a differential probe in the opposite direction. Figure 3For example, sensor probe a is installed in the X+ direction, and sensor probe b is installed in the X- direction. When the rotor under test undergoes displacement in the X direction, sensor probe a and sensor probe b output opposite signals; when the rotor under test undergoes displacement in the Z direction, sensor probe a and sensor probe b output the same signal. Adding the signals from sensor probe a and sensor probe b eliminates the X-direction displacement signal, leaving only the Z-direction displacement signal; subtracting the signals from sensor probe a and sensor probe b eliminates the Z-direction displacement signal, leaving only the X-direction displacement signal. This allows for simultaneous displacement detection in both the X and Z directions using an X-direction probe.

[0006]

[0007] U+: Voltage of probe a, U-: Voltage of probe b, Kx: Radial sensitivity, Kz: Axial sensitivity, X: Radial displacement, Z: Axial displacement.

[0008] However, due to the presence of high-order coupling terms in the X and Z displacement signals, decoupling cannot be achieved through simple superposition and subtraction operations. In practical applications, this coupling leads to poor detection accuracy and fails to meet detection requirements.

[0009]

[0010] U+: Voltage of probe a, U-: Voltage of probe b, Kxx: Radial quadratic coefficient, Kx: Radial sensitivity; Kz: Axial sensitivity, K: Coupling coefficient, X: Radial displacement, Z: Axial displacement.

[0011] There is also a background technology that can improve detection accuracy, such as Figure 4 As shown, the axial displacement calculation unit is used to calculate the displacement according to the formula. Calculate the axial displacement of the measured element; wherein Ur is the first electrical signal, Uz is the second electrical signal, φ is the tilt angle of the inclined surface, k1 is the sensitivity parameter of the first sensor, and k2 is the sensitivity parameter of the second sensor.

[0012] However, it has the following limitations: 1. It requires both probes to be aligned with the central axis of the probe ring and to be installed in the same direction, which results in the probe installation occupying too large an axial dimension, further increasing the rotor length and affecting the dynamic characteristics of the rotor operation; 2. The axial length of the inclined surface is greater than the maximum axial displacement of the measured element, which means that the rotor length is related to the axial displacement and the sensor probe size, and needs to be further increased, resulting in low space utilization.

[0013] Because existing displacement sensors cannot output the displacement in each direction separately when detecting displacement in multiple directions, and differential sensors cannot be decoupled due to high-order coupling terms, resulting in poor detection accuracy; and displacement sensors with inclined plane structures increase the probe spacing, resulting in excessive axial dimensions and low space utilization, etc., this invention studies and designs a sensor assembly and motor for rotor displacement detection. Summary of the Invention

[0014] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the displacement sensor in the prior art cannot output the displacement amount in each direction separately and accurately when realizing the detection of displacement in multiple directions, resulting in poor detection accuracy, and thus provides a sensor component and motor for rotor displacement detection.

[0015] To address the above problems, the present invention provides a sensor assembly for rotor displacement detection, comprising:

[0016] The test rotor, sensor probe, and compensation probe are provided. The test rotor includes an axial detection position. The sensor probe is located radially outside the axial detection position and is radially opposite to the axial detection position. The compensation probe is located radially outside the test rotor and is not opposite to the axial detection position. Let the direction along the central axis of the test rotor be the Z-axis, and the direction perpendicular to the Z-axis and passing through the center of the sensor probe be the X-axis. The following are also provided:

[0017]

[0018] Where: U1: sensor probe voltage, U 补偿 : Compensation probe voltage, K xx : Radial quadratic coefficient, K x Radial sensitivity, K z : Axial sensitivity, K: Coupling term coefficient, X: Displacement of the measured rotor along the X-axis, Z: Displacement of the measured rotor along the Z-axis.

[0019] In some implementations...

[0020] The rotor under test is a stepped shaft, which includes a first shaft segment and a second shaft segment that are connected. The outer diameter of the first shaft segment is smaller than the outer diameter of the second shaft segment, so as to form a stepped surface at the junction of the first shaft segment and the second shaft segment. The axial detection position includes the stepped surface.

[0021] The step surface is arranged radially opposite to the sensor probe; the compensation probe is arranged radially outside the first shaft segment and is not opposite to the step surface, or the compensation probe is arranged radially outside the second shaft segment and is not opposite to the step surface.

[0022] In some implementations...

[0023] The central axes of the first and second shaft segments coincide, and the positive direction of the Z-axis is the direction from the second shaft segment to the first shaft segment. The point where the plane containing the step surface intersects the central axis is point O. The center of the sensor probe is opposite to the step surface. The direction of the line connecting point O to the center of the sensor probe is the positive direction of the X-axis. The direction perpendicular to the X-axis in the plane containing the step surface is the Y-axis direction.

[0024] In some implementations...

[0025] The axial detection position is the position of the step surface offset by a distance 'a' in the positive direction of the Z-axis, where a ≥ 0, and / or, the axial detection position is the position of the step surface offset by a distance 'b' in the negative direction of the Z-axis, where b ≥ 0.

[0026] In some implementations...

[0027] The sensor probe has a first preset distance from the radial outer periphery of the axial detection position that is greater than 0. The compensation probe is disposed on the radial outer side of the second shaft segment and has a second preset distance from the outer periphery of the second shaft segment that is greater than 0. The compensation probe has a third preset distance from the axial detection position along the Z-axis that is greater than 0.

[0028] In some implementations...

[0029] In the axial projection plane toward the stepped surface, the compensation probe and the sensor probe are positioned offset from each other.

[0030] In some implementations...

[0031] There are two or more compensation probes, all of which are located in a plane perpendicular to the central axis of the rotor being tested, and are spaced apart along the circumferential direction.

[0032] In some implementations...

[0033] The at least two compensation probes include a compensation probe disposed at a first circumferential position and a compensation probe disposed at a second circumferential position, the second circumferential position being a position rotated 90° in the circumferential direction.

[0034] In some implementations...

[0035] The at least two compensation probes include a compensation probe located at a third circumferential position, a compensation probe located at a fourth circumferential position, a compensation probe located at a fifth circumferential position, and a compensation probe located at a sixth circumferential position, wherein the third circumferential position, the fourth circumferential position, the fifth circumferential position, and the sixth circumferential position are spaced 90° apart in the circumferential direction.

[0036] The present invention also provides an electric motor that includes the aforementioned sensor assembly for rotor displacement detection.

[0037] The sensor assembly and motor for rotor displacement detection provided by this invention have the following beneficial effects:

[0038] 1. This invention, by setting a sensor probe and a compensation probe, with the sensor probe positioned opposite the axial detection position, can detect and obtain the rotor displacement in both the axial and radial directions. Simultaneously, by adding a compensation probe along the Z-axis, the rotor displacement in the radial direction can be obtained, i.e., for detecting the X-direction displacement. The X-direction displacement signal is fed back to the sensor probe, and after subsequent processing, the axial displacement signal can be output. This effectively decouples the radial and axial displacement signals of the rotor, simplifying the calculation and increasing accuracy. Compared to prior art Z-direction sensors (…), this invention… Figure 1 The proposed solution eliminates the need for an axial inspection ring, improving assembly efficiency and reducing costs compared to other solutions. Figure 2 The proposed solution can output displacements in multiple directions, compared to the differential structure in the background technology. Figure 3 The proposed solution does not have high-order coupling terms and has high detection accuracy; compared to the inclined plane structure in the background technology ( Figure 4 The proposed solution shortens the probe spacing, overcomes the problem of high-order coupling terms, and improves space utilization. Compared with the prior art, the structure of this invention achieves radial installation of the probe to detect axial displacement without increasing the number of sensor probes. It does not have high-order coupling terms and avoids the coupling problem of displacement output in different directions in the original technology. It can simultaneously realize the output of displacement signals in both X and Z directions, achieving high detection accuracy. It does not require too many structures and greatly compresses the axial dimensions of the sensor and the rotor measured surface. It has the advantages of high accuracy, low cost, and compact space layout.

[0039] 2. This invention eliminates the need for the prior art by arranging radial compensation probes. Figure 3 The opposite axial differential probe does not require machining of conventional axial detection surfaces or axial detection rings. Figure 1This eliminates the need for an additional sealing disc structure in the axial direction, shortening the shaft length; it also reduces the axial dimensions of the sensor and rotor, improving space utilization. Attached Figure Description

[0040] Figure 1 This is a structural diagram of the prior art solution 1;

[0041] Figure 2 This is a structural diagram of the existing technology's Scheme 2;

[0042] Figure 3 This is a structural diagram of the existing technology's solution 3;

[0043] Figure 4 This is a structural diagram of the existing technology's Scheme 4;

[0044] Figure 5 This is a front structural view of the sensor assembly for rotor displacement detection of the present invention;

[0045] Figure 6 This is a three-dimensional structural diagram of the sensor assembly for rotor displacement detection of the present invention (Example 1);

[0046] Figure 7 yes Figure 6 The right-side side view;

[0047] Figure 8 This is a three-dimensional structural diagram of the sensor assembly for rotor displacement detection of the present invention (Example 2);

[0048] Figure 9 yes Figure 8 The right-side side view.

[0049] The attached figures are labeled as follows:

[0050] 1. Compensation probe; 2. Sensor probe; 3. Rotor under test; 31. Axial detection position; 32. First shaft segment; 33. Second shaft segment. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0053] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0054] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0055] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0056] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0057] For example Figure 5-9 As shown, the present invention provides a sensor assembly for rotor displacement detection, comprising:

[0058] The test rotor 3, sensor probe 2, and compensation probe 1 are included. The test rotor 3 includes an axial detection position 31. The sensor probe 2 is located radially outside the axial detection position 31 and is radially opposite to the axial detection position 31. The compensation probe 1 is located radially outside the test rotor 3 and is not opposite to the axial detection position 31. Let the direction along the central axis of the test rotor 3 be the Z-axis direction, and let the direction perpendicular to the Z-axis and passing through the center of the sensor probe 2 be the X-axis direction. The following are also provided:

[0059]

[0060] Where: U1: sensor probe voltage, U 补偿 : Compensation probe voltage, K xx : Radial quadratic coefficient, K x Radial sensitivity, K z : Axial sensitivity, K: Coupling term coefficient, X: Displacement of the measured rotor along the X-axis (i.e., radial displacement), Z: Displacement of the measured rotor along the Z-axis (i.e., axial displacement).

[0061] This invention, by setting up a sensor probe and a compensation probe, with the sensor probe positioned opposite the axial detection position, can detect and obtain the rotor displacement in both the axial and radial directions. Simultaneously, by adding a compensation probe along the Z-axis, the rotor displacement in the radial direction can be obtained, i.e., for detecting the X-direction displacement. The X-direction displacement signal is fed back to the sensor probe, and after subsequent processing, the axial displacement signal is output. This effectively decouples the radial and axial displacement signals of the rotor, simplifying the calculation and increasing accuracy. Compared to prior art Z-direction sensors... Figure 1 The proposed solution eliminates the need for an axial inspection ring, improving assembly efficiency and reducing costs compared to other solutions. Figure 2 The proposed solution can output displacements in multiple directions, compared to the differential structure in the background technology. Figure 3 The proposed solution does not have high-order coupling terms and has high detection accuracy; compared to the inclined plane structure in the background technology ( Figure 4 The proposed solution shortens the probe spacing, overcomes the problem of high-order coupling terms, and improves space utilization. Compared with the prior art, the structure of this invention achieves radial installation of the probe to detect axial displacement without increasing the number of sensor probes. It does not have high-order coupling terms and avoids the coupling problem of displacement output in different directions in the original technology. It can simultaneously realize the output of displacement signals in both X and Z directions, achieving high detection accuracy. It does not require too many structures and greatly compresses the axial dimensions of the sensor and the rotor measured surface. It has the advantages of high accuracy, low cost, and compact space layout.

[0062] The sensor assembly of this invention comprises a radial sensor probe (i.e., compensation probe 1), an axial sensor probe (i.e., sensor probe 2), and a rotor under test 3. To enable the radial probe to detect axial displacement, a specially designed axial detection position 31 is required on the rotor. By arranging the radial compensation probe, the prior art is eliminated. Figure 3 The opposite axial differential probe does not require machining of conventional axial detection surfaces or axial detection rings. Figure 1 This eliminates the need for an additional sealing disc structure in the axial direction, shortening the shaft length; it also reduces the axial dimensions of the sensor and rotor, improving space utilization.

[0063] During testing, the signals from the two opposing radial sensor probes (i.e., compensation probe 1) are differentially divided to output radial displacement signals. The two pairs of compensation probes 1, totaling four, output radial displacement signals in the X and Y directions of the rotor under test, respectively. After the radial X and Y displacement signals are processed by the signal processing circuit and the coordinate system is transformed, the radial displacement signal corresponding to the radial angle of the axial sensor probe (i.e., sensor probe 2) can be obtained. As described in the background technology, the radial displacement signal corresponding to the radial angle of the sensor probe 2 is calculated by the compensation probe 1 and then used to compensate the radial and axial displacement signals measured by the sensor probe 2. This allows the radial and axial displacement signals measured by the sensor probe 2 to be separated, enabling the sensor probe 2 to output an axial displacement signal.

[0064] In some implementations...

[0065] The rotor under test 3 is a stepped shaft, which includes a first shaft segment 32 and a second shaft segment 33 that are connected. The outer diameter of the first shaft segment 32 is smaller than the outer diameter of the second shaft segment 33, so as to form a stepped surface at the junction of the first shaft segment 32 and the second shaft segment 33. The axial detection position 31 includes the stepped surface.

[0066] The step surface is arranged radially opposite to the sensor probe 2. The compensation probe 1 is arranged radially outside the first shaft segment 32 and is not opposite to the step surface, or the compensation probe 1 is arranged radially outside the second shaft segment 33 and is not opposite to the step surface.

[0067] This is the preferred structural form of the rotor under test in this invention. A stepped shaft is formed by connecting two shaft segments with different outer diameters. A sensor probe is set at or near the stepped surface (the stepped surface and the sensor probe are arranged radially opposite each other). Since the rotor will have axial movement, while the sensor probe is fixed, it is necessary to ensure that the axial detection position is always within the detection range of the sensor probe. The sensor probe corresponds to the axial detection position, so the moving stepped surface must be within the detection range of the sensor probe to effectively ensure that a signal is generated and output for the axial displacement of the stepped shaft. The compensation probe is set at a position not opposite to the stepped surface, so that the compensation probe detects the radial displacement of the rotor and generates a signal output. Finally, by decoupling the two, the axial displacement signal and the radial displacement signal can be effectively obtained separately.

[0068] In some implementations...

[0069] The central axes of the first shaft segment 32 and the second shaft segment 33 coincide, and the positive direction of the Z-axis is the direction from the second shaft segment 33 toward the first shaft segment 32. The point where the plane containing the step surface intersects the central axis is point O. The center of the sensor probe 2 is opposite to the step surface. The direction of the line connecting point O to the center of the sensor probe 2 is the positive direction of the X-axis. The direction in the plane containing the step surface and perpendicular to the X-axis is the Y-axis direction.

[0070] This describes the specific form of the first and second shaft segments and the X, Z, and Y directions of the present invention. The first and second shaft segments are coaxial shaft segment structures, and the Z-axis is square, extending from the second shaft segment toward the first shaft segment, as shown below. Figure 5 The line connecting point O and the sensor probe forms a square along the X-axis, as shown below. Figure 5 As shown, the Y-axis lies in the same radial plane as the X-axis and is perpendicular to the X-axis.

[0071] In some implementations...

[0072] The axial detection position 31 is the position of the step surface offset by a distance a in the positive direction of the Z-axis, where a≥0, and / or, the axial detection position 31 is the position of the step surface offset by a distance b in the negative direction of the Z-axis, where b≥0.

[0073] This is the preferred positional relationship between the axial detection position and the step surface of the present invention. The axial detection position is relative to the radially inner position of the sensor probe. Since the rotor is moving, it is centered on the step surface and moves towards... Figure 5 There are motion errors in both the left and right directions. Within the distance range of a to b, the sensor probe can effectively detect the signal of the axial detection position and output the signal of axial displacement.

[0074] In some implementations...

[0075] The sensor probe 2 has a first preset distance greater than 0 from the radial outer periphery of the axial detection position 31. The compensation probe 1 is disposed on the radial outer side of the second shaft segment 33 and has a second preset distance greater than 0 from the outer periphery of the second shaft segment 33. The compensation probe 1 has a third preset distance greater than 0 from the axial detection position 31 along the Z-axis direction.

[0076] This is a preferred structural form of the sensor probe and compensation probe of the present invention, respectively, relative to the axial detection position. The sensor probe is radially opposite to the axial detection position and located at a distance greater than 0 outside the axial detection position to detect the displacement signal of the axial detection position. The compensation probe is not opposite to the axial detection position and is spaced at a third preset distance greater than 0 along the Z-axis direction, which enables the axial detection position to be located outside the detection range of the compensation probe, thereby avoiding interference of the axial detection position with the radial displacement signal detection of the compensation probe and effectively improving the accuracy of displacement output in the X and Z directions.

[0077] In some implementations...

[0078] In the axial projection plane toward the stepped surface, the compensation probe 1 and the sensor probe 2 are staggered. Furthermore, by circumferentially staggering the compensation probe and the sensor spring, the present invention can further effectively compress the axial dimension of the entire sensor, allowing for a smaller axial volume and improved space utilization.

[0079] During assembly, the axial sensor probe (i.e., sensor probe 2) must be aligned with the axial detection position 31, and the axial movement range of the rotor 3 under test must ensure that the axial detection position 31 is always within the detection range of sensor probe 2. The four radial sensor probes (i.e., compensation probes 1) are evenly distributed along the circumference of the rotor 3 under test, avoiding the axial detection position 31, and the axial movement range of the rotor 3 under test must ensure that the axial detection position 31 is always outside the detection range of compensation probes 1. The radial sensor probes (compensation probes 1) and the axial sensor probes (sensor probe 2) are offset at a certain angle in the circumferential direction, which can further compress the overall axial dimension of the sensor.

[0080] In some implementations...

[0081] There are two or more compensation probes 1, and all two or more compensation probes 1 are located in a plane perpendicular to the central axis of the rotor 3 under test, and the two or more compensation probes 1 are spaced apart along the circumferential direction.

[0082] This is a preferred structural form of the compensation probe of the present invention. By using two or more compensation probes, at least one of which is used to detect the displacement signal of the rotor in the X direction and at least one of which is used to detect the displacement signal of the rotor in the Y direction, displacement output signals in the X, Y and Z directions can be output, thereby further improving the accuracy of displacement detection.

[0083] Example 2, as Figure 8-9 In some implementation methods,

[0084] The at least two compensation probes 1 include a compensation probe disposed at a first circumferential position and a compensation probe disposed at a second circumferential position, the second circumferential position being a position rotated 90° in the circumferential direction.

[0085] This is a preferred structural form of Embodiment 2 of the present invention, which includes two compensation probes, one of which is 90° apart from the other in the circumferential direction. Different radial displacement signals can be obtained by detecting the two probes to obtain displacement output signals in the X and Y directions.

[0086] The optimal implementation requires four radial sensor probes (i.e., compensation probes 1), mainly to improve detection accuracy and reliability through signal differential between two opposing radial sensor probes. If the requirements for detection accuracy and reliability are not high, two radial sensor probes (i.e., compensation probes 1) can be installed at 90° intervals along the circumference of the rotor 3 being measured. In this case, the axial sensor probe (i.e., sensor probe 2) can be installed on the opposite side of one radial sensor probe (compensation probe 1), which can eliminate the coordinate system transformation part of the signal processing circuit in the optimal implementation, further saving costs.

[0087] Example 1, as Figure 6-7 In some implementation methods,

[0088] The at least two compensation probes 1 include a compensation probe located at a third circumferential position, a compensation probe located at a fourth circumferential position, a compensation probe located at a fifth circumferential position, and a compensation probe located at a sixth circumferential position, wherein the third circumferential position, the fourth circumferential position, the fifth circumferential position, and the sixth circumferential position are spaced 90° apart in the circumferential direction.

[0089] This is a preferred structural form of Embodiment 1 of the present invention, which includes four compensation probes. The four compensation probes are arranged at 90° intervals in the circumferential direction. The radial displacement signal in the X direction can be detected by at least two compensation probes spaced at 180° intervals, and the radial displacement signal in the Y direction can be detected by the other at least two compensation probes spaced at 180° intervals.

[0090] The present invention also provides an electric motor that includes the aforementioned sensor assembly for rotor displacement detection.

[0091] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A sensor assembly for rotor displacement detection, characterized in that: include: The test rotor (3), sensor probe (2), and compensation probe (1) are provided. The test rotor (3) includes an axial detection position (31). The sensor probe (2) is located radially outside the axial detection position (31) and is radially opposite to the axial detection position (31). The compensation probe (1) is located radially outside the test rotor (3) and is not opposite to the axial detection position (31). Let the direction along the central axis of the test rotor (3) be the Z-axis direction, and the direction perpendicular to the Z-axis radial plane and passing through the center of the sensor probe (2) be the X-axis direction. The following are also provided: ； Where: U1: sensor probe voltage, U 补偿 : Compensation probe voltage, K xx : Radial quadratic coefficient, K x Radial sensitivity, K z : Axial sensitivity, K: Coupling term coefficient, X: Displacement of the measured rotor along the X-axis, Z: Displacement of the measured rotor along the Z-axis.

2. The sensor assembly for rotor displacement detection according to claim 1, characterized in that: The rotor under test (3) is a stepped shaft, which includes a first shaft segment (32) and a second shaft segment (33) that are connected. The outer diameter of the first shaft segment (32) is smaller than the outer diameter of the second shaft segment (33) to form a stepped surface at the junction of the first shaft segment (32) and the second shaft segment (33). The axial detection position (31) includes the stepped surface. The sensor probe (2) is arranged radially opposite to the stepped surface; The compensation probe (1) is located on the radial outer side of the first shaft segment (32) and is not opposite to the step surface, or the compensation probe (1) is located on the radial outer side of the second shaft segment (33) and is not opposite to the step surface.

3. The sensor assembly for rotor displacement detection according to claim 2, characterized in that: The central axis of the first shaft segment (32) coincides with that of the second shaft segment (33), and the positive direction of the Z-axis is the direction from the second shaft segment (33) toward the first shaft segment (32). The point where the plane containing the step surface intersects with the central axis is point O. The center of the sensor probe (2) is opposite to the step surface. The direction of the line connecting point O to the center of the sensor probe (2) is the positive direction of the X-axis. The direction in the plane containing the step surface and perpendicular to the X-axis is the Y-axis direction.

4. The sensor assembly for rotor displacement detection according to claim 2, characterized in that: The axial detection position (31) is the position of the step surface offset by a distance in the positive direction of the Z-axis, where a≥0, and / or, the axial detection position (31) is the position of the step surface offset by b distance in the negative direction of the Z-axis, where b≥0.

5. The sensor assembly for rotor displacement detection according to claim 2, characterized in that: The sensor probe (2) has a first preset distance from the axial detection position (31) with a radial outer periphery interval greater than 0. The compensation probe (1) is located on the radial outer side of the second shaft segment (33) and has a second preset distance from the outer periphery of the second shaft segment (33) with a distance greater than 0. The compensation probe (1) has a third preset distance from the axial detection position (31) along the Z-axis direction with a distance greater than 0.

6. The sensor assembly for rotor displacement detection according to claim 2, characterized in that: In the axial projection plane toward the stepped surface, the positions of the compensation probe (1) and the sensor probe (2) are staggered.

7. The sensor assembly for rotor displacement detection according to any one of claims 1-6, characterized in that: There are two or more compensation probes (1), and all two or more compensation probes (1) are located in a plane perpendicular to the central axis of the rotor (3) being measured, and the two or more compensation probes (1) are spaced apart along the circumferential direction.

8. The sensor assembly for rotor displacement detection according to claim 7, characterized in that: The at least two compensation probes (1) include a compensation probe disposed at a first circumferential position and a compensation probe disposed at a second circumferential position, the second circumferential position being a position where the first circumferential position is rotated 90° in the circumferential direction.

9. The sensor assembly for rotor displacement detection according to claim 7, characterized in that: The at least two compensation probes (1) include a compensation probe located at a third circumferential position, a compensation probe located at a fourth circumferential position, a compensation probe located at a fifth circumferential position, and a compensation probe located at a sixth circumferential position, wherein the third circumferential position, the fourth circumferential position, the fifth circumferential position, and the sixth circumferential position are spaced 90° apart in the circumferential direction.

10. An electric motor, characterized in that: The sensor assembly for rotor displacement detection includes any one of claims 1-9.

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