Tool and method for detecting concentricity of radial sensor of magnetic suspension molecular pump

Abstract

The invention discloses a concentricity detection tool and method for a radial sensor of a magnetic suspension molecular pump, and belongs to the technical field of concentricity detection, and the technical key points are that the concentricity detection tool comprises a high-precision rotation platform assembly which serves as a placement platform of a radial stator assembly to be detected; the high-precision rotary platform assembly comprises a V-shaped positioning block, a clamping device and a precision rotary main shaft driving rotary table; the V-shaped positioning block and the clamping device are used for fixing the radial stator assembly to be tested on the precise rotation main shaft driving rotary table; the precise rotary main shaft driving rotary table is used for driving a radial stator assembly to be tested to perform rotary motion; the tool shaft motion control assembly can control the tool shaft to enter the radial stator assembly to be tested. According to the technical scheme, the concentricity of the upper radial sensor and the lower radial sensor of the radial stator assembly to be tested can be tested.

Description

Technical Field

[0001] This application relates to the field of concentricity testing, and more specifically, to a tooling and method for detecting the concentricity of a radial sensor of a magnetically levitated molecular pump. Background Technology

[0002] The radial stator assembly is the most critical core component of the magnetic levitation molecular pump, directly driving the rotor to rotate at high speed by magnetic levitation. Figure 1 The diagram illustrates the structure of the radial stator assembly. The radial stator assembly consists of an upper magnetic bearing 1, an upper radial sensor 2, a lower radial sensor 3, a lower magnetic bearing 4, a stator motor, and bearing housings. The upper and lower radial sensors are primarily used to read the real-time position information of the rotor's rotation axis center and transmit the position signals to the upper and lower magnetic bearings respectively. The accuracy of the position signal reading depends on the concentric alignment of the upper and lower radial sensors.

[0003] After the upper magnetic bearing, lower magnetic bearing, upper radial sensor, lower radial sensor, stator motor and bearing housing are installed, their coaxiality is guaranteed by the inner hole accuracy of the external bearing housing (approximately 0.01mm). However, since the sensor has an adjustment positioning slider, during the initial debugging and installation of a single sensor, the measuring point on the positioning slider is adjusted to be tangent to the inner circle of the sensor and then tightened with positioning screws.

[0004] On the one hand, the sensor slider requires high dimensional accuracy, and when the screw is tightened, it will inevitably cause the sensor slider to have a certain amount of displacement or small-angle rotation.

[0005] On the other hand, after the two sensors are assembled into finished products, although the upper and lower radial sensors are guaranteed to be coaxial to a certain extent by the inner diameter of the bearing housing, the bearing housing expands under high temperature baking during the assembly process, and after cooling, it achieves an interference fit with the outer diameter of the five parts. In addition, the upper and lower bearing housings and the motor housing are all made of steel, while only the sensors and bearing housings are made of aluminum alloy, which inevitably results in a certain amount of variation (the measured results exceed 0.005mm, and are basically distributed between 0.005-0.01mm).

[0006] The difference between the outer diameter of the rotor and the inner diameter of the radial stator is only 0.1mm. The above two aspects will cause some data drift to exceed 10%, which will have a significant impact on the stability of the rotor during high-speed rotation. This will cause the molecular pump rotor to vibrate out of tolerance, and in severe cases, even violent shaking and instability may occur. In more serious cases, there is a risk of serious accidents such as rotor turbine breakage.

[0007] The research team believes that it is necessary to detect the concentricity of the radial sensor of the magnetically levitated molecular pump. However, there is currently no relevant research on the detection of the concentricity of the radial sensor of the magnetically levitated molecular pump. Summary of the Invention

[0008] The purpose of this application is to provide a concentricity detection fixture for a radial sensor of a magnetic levitation molecular pump, addressing the shortcomings of the prior art.

[0009] Another objective of this application is to provide a method for detecting the concentricity of a radial sensor for a magnetically levitated molecular pump.

[0010] Another objective of this application is to provide a method for testing the concentricity of a radial sensor for a magnetically levitated molecular pump.

[0011] The technical solution of this application is as follows: A concentricity testing fixture for radial sensors of a magnetic levitation molecular pump is used to test the concentricity of the upper and lower radial sensors of the radial stator assembly under test. It includes: a. Tooling shaft, which is set in a vertical position and is located at the lower part of the moving end of the tooling shaft motion control assembly; b. Tooling axis motion control assembly, which is used to control the position of the tooling axis; the tooling axis motion control assembly can control the tooling axis to move in the vertical direction; c. A high-precision rotary platform assembly, which serves as a placement platform for the radial stator assembly to be tested; the high-precision rotary platform assembly includes: a V-shaped positioning block, a clamping device, and a precision rotary spindle drive turntable; The V-shaped positioning block and the clamping device are used to fix the radial stator assembly to be tested on the precision rotary spindle drive turntable. The precision rotary spindle drive turntable is used to drive the radial stator assembly under test to rotate. d. The tooling axis motion control component can control the tooling axis to enter the radial stator assembly to be measured.

[0012] Furthermore, the high-precision rotary platform component also includes: an angle sensor; the angle sensor is used to measure the rotation angle of the precision rotary spindle-driven turntable.

[0013] Furthermore, the rotation axis of the precision rotary spindle drive turntable is coaxial with the rotation axis of the bearing housing of the radial stator assembly under test.

[0014] Furthermore, the tooling axis motion control assembly can also control the tooling axis to move in the horizontal direction.

[0015] Furthermore, the difference between the diameter of the inner cylindrical surface of the upper radial sensor of the radial stator assembly and the outer surface diameter of the tooling shaft is 2 mm.

[0016] Furthermore, the tooling axis motion control assembly can control the tooling axis to extend into the lower radial sensor of the radial stator assembly under test, so that both the upper and lower radial sensors of the radial stator assembly under test can measure data.

[0017] A method for detecting the concentricity of radial sensors in a magnetically levitated molecular pump, which tests the concentricity of the upper and lower radial sensors of the radial stator assembly under test; The upper radial sensor has four measuring points, with a phase angle of 90° between the four measuring points, denoted as the first to fourth measuring points; the lower radial sensor has four measuring points, with a phase angle of 90° between the four measuring points, denoted as the fifth to eighth measuring points; the first measuring point is the X+ measuring point, the second measuring point is the Y+ measuring point, the third measuring points 1-3 are the X- measuring points, the fourth measuring point is the Y- measuring point; the fifth measuring point is the X+ measuring point, the sixth measuring point is the Y+ measuring point, the seventh measuring point is the X- measuring point, and the eighth measuring point is the Y- measuring point; It includes the following steps: S100, the radial stator assembly to be tested is mounted on the precision rotary spindle drive turntable: the radial stator assembly to be tested is fixed on the precision rotary spindle drive turntable by means of V-shaped positioning blocks and clamping devices; S200, the tooling axis motion control assembly moves the tooling axis so that the tooling axis is inserted into the radial stator assembly to be tested; S300, test δ 短1 ~δ 短8 δ 长1 ~δ 短8 ; For any δ 短i δ 长i The testing method is as follows: The precision rotary spindle drives the turntable to rotate the radial stator assembly under test one revolution. During this process, the minimum distance measured at the i-th measuring point is δ. 短i The maximum distance is δ 长i ; S400, solve for the eccentricity L between the center points of the upper radial sensor and the lower radial sensor; L=0.5×[(δ 短5 +δ 长5 -δ 短7 -δ 长7 -δ 短1 -δ 长1 +δ 短3 +δ 长3 ) 2 + (δ) 短6 +δ 长6 -δ 短8 -δ 长8 -δ 短2 -δ 长2 +δ 短4 +δ 长4 ) 2 ] 0.5 .

[0018] A method for detecting the concentricity of radial sensors in a magnetically levitated molecular pump, which tests the concentricity of the upper and lower radial sensors of the radial stator assembly under test; The upper radial sensor has four measuring points, with a phase angle of 90° between the four measuring points, denoted as the first to fourth measuring points; the lower radial sensor has four measuring points, with a phase angle of 90° between the four measuring points, denoted as the fifth to eighth measuring points; the first measuring point is the X+ measuring point, the second measuring point is the Y+ measuring point, the third measuring points 1-3 are the X- measuring points, the fourth measuring point is the Y- measuring point; the fifth measuring point is the X+ measuring point, the sixth measuring point is the Y+ measuring point, the seventh measuring point is the X- measuring point, and the eighth measuring point is the Y- measuring point; It includes the following steps: S100, the radial stator assembly to be tested is mounted on the precision rotary spindle drive turntable: the radial stator assembly to be tested is fixed on the precision rotary spindle drive turntable by means of V-shaped positioning blocks and clamping devices; S200, the tooling axis motion control assembly moves the tooling axis so that the tooling axis is inserted into the radial stator assembly to be tested; S300, solve for the eccentricity L between the center points of the upper radial sensor and the lower radial sensor; L can be any one or the average of any two of L1, L2, L3, and L4, or the average of any three or four of them. L1 is the eccentricity calculated using the fourth and second measuring points of the upper radial sensor and the eighth and sixth measuring points of the lower radial sensor. L2 is the eccentricity calculated using the fourth and second measuring points of the upper radial sensor and the seventh and fifth measuring points of the lower radial sensor. L3 is the eccentricity calculated by using the third and first measuring points of the upper radial sensor and the eighth and sixth measuring points of the lower radial sensor. L4 is the eccentricity calculated using the third and first measuring points of the upper radial sensor and the seventh and fifth measuring points of the lower radial sensor. The eccentricity L is calculated by using the p-th and q-th measuring points of the upper radial sensor and the m-th and n-th measuring points of the lower radial sensor. s The method includes the following sub-steps: S401, Test δ 短 p、δ 短q δ 短 m、δ 短 n、δ 长 p、δ 长q δ 长 m、δ 长 n、D 测p D 测q D 测m D 测n ; For any δ 短iδ 长i D 测i , where i is any value of p, q, m, n, and is obtained as follows: The precision rotary spindle drives the turntable to rotate the radial stator assembly under test one revolution. During this process, the minimum distance measured at the i-th measuring point is δ. 短i The maximum distance is δ 长i ; D 测i =δ 短i +δ 长i +D0,D 测i Di represents the rotation diameter of the i-th measuring point, and D0 represents the diameter of the tooling shaft; S402, Test β pq β mq β nq : For any β vq , refers to the angle between AQ and AV when AQ rotates counterclockwise, where v is any value of p, m, and n; A, Q, and V represent the rotation axis of the precision rotary spindle drive turntable, the projection points of the q-th and v-th measuring points on the same horizontal plane, respectively; the test method is as follows: Step a: Rotate the precision rotary spindle drive turntable until the minimum distance value measured at the v-th measuring point is obtained, taking this as the starting point. Rotate the precision rotary spindle drive turntable clockwise until the minimum distance value measured at the q-th measuring point is obtained, taking this as the ending point. The angle rotated by the precision rotary spindle drive turntable from the starting point to the ending point is denoted as β. vq-顺 ; Step b: Rotate the precision rotary spindle drive turntable until the minimum distance measured at the v-th measuring point is obtained, taking this as the starting point. Rotate the precision rotary spindle drive turntable counterclockwise until the minimum distance measured at the q-th measuring point is obtained, taking this as the ending point. The angle rotated by the precision rotary spindle drive turntable from the starting point to the ending point is denoted as β. vq-逆 ; β vq =β vq-逆 -(β) vq-顺+ β vq-逆 -360°) / 2; S403, Solve for L s : L s =0.5×((D) 测m ·cosβ mq + D 测n ·cosβ nq -D 测q -D 测p ·cosβ pq ) 2 +(D) 测m ·sinβmq +D 测n ·sinβ nq -D 测p ·sinβ pq ) 2 ) 0.5 .

[0019] Furthermore, the S200 also includes: a precision rotary spindle drive turntable that rotates the radial stator assembly to be tested to run-in the rotation mechanism.

[0020] A method for testing the concentricity of radial sensors in a magnetically levitated molecular pump involves testing the concentricity of the upper and lower radial sensors of the radial stator assembly under test at least twice. During each test, the position of the tooling axis is different, that is, the motion control component moves the tooling axis to different positions. Then, the concentricity detection method of the radial sensor of the magnetic levitation molecular pump described above is used to test the concentricity of the upper radial sensor and the lower radial sensor of the radial stator assembly under test. If the detected eccentricity L is less than the eccentricity threshold [L] each time, it indicates that the concentricity of the radial sensor of the magnetic levitation molecular pump is qualified; otherwise, it is unqualified.

[0021] The beneficial effects of this application are as follows: First, this application develops a concentricity detection fixture for a radial sensor of a magnetically levitated molecular pump. The core of the hardware design lies in: "a fixture axis motion control component capable of controlling the vertical movement of the fixture axis, i.e., controlling the insertion of the fixture axis into the radial stator assembly under test (the fixture axis only needs one vertical degree of freedom)"; and "a high-precision rotary platform component, serving as a placement platform for the radial stator assembly under test; the high-precision rotary platform component includes: a V-shaped positioning block, a clamping device, and a precision rotary spindle drive turntable; the V-shaped positioning block and the clamping device are used to fix the radial stator assembly under test on the precision rotary spindle drive turntable; the precision rotary spindle drive turntable is used to drive the radial stator assembly under test to rotate." Through the coordinated operation of the above design, the concentricity detection of the radial sensor of the magnetically levitated molecular pump can be achieved.

[0022] In addition, during the hardware design, "the rotation axis of the precision rotary spindle drive turntable is coaxial with the rotation axis of the bearing housing of the radial stator assembly under test (to be precise, the axial distance between the rotation axis of the precision rotary spindle drive turntable and the rotation axis of the bearing housing of the radial stator assembly under test is less than half the difference between the diameter of the inner cylindrical surface of the upper radial sensor of the radial stator assembly and the outer surface diameter of the tooling shaft)" to avoid collision between the precision rotary spindle drive turntable and the tooling shaft when the precision rotary spindle drive turntable rotates.

[0023] Secondly, the concentricity detection method of the radial sensor of the magnetic levitation molecular pump is another research and development challenge of this application. This application proposes the following two methods for concentricity detection.

[0024] The first method: S100, the radial stator assembly to be tested is mounted on the precision rotary spindle drive turntable: the radial stator assembly to be tested is fixed on the precision rotary spindle drive turntable by means of V-shaped positioning blocks and clamping devices; S200, the tooling axis motion control assembly moves the tooling axis so that the tooling axis is inserted into the radial stator assembly to be tested; S300, solve for the eccentricity L between the center points of the upper radial sensor and the lower radial sensor; L can be any one or the average of any two of L1, L2, L3, and L4, or the average of any three or four of them. L1 is the eccentricity calculated using the fourth and second measuring points of the upper radial sensor and the eighth and sixth measuring points of the lower radial sensor. L2 is the eccentricity calculated using the fourth and second measuring points of the upper radial sensor and the seventh and fifth measuring points of the lower radial sensor. L3 is the eccentricity calculated by using the third and first measuring points of the upper radial sensor and the eighth and sixth measuring points of the lower radial sensor. L4 is the eccentricity calculated using the third and first measuring points of the upper radial sensor and the seventh and fifth measuring points of the lower radial sensor. The eccentricity L is calculated by using the p-th and q-th measuring points of the upper radial sensor and the m-th and n-th measuring points of the lower radial sensor. s The method includes the following sub-steps: S401, Test δ 短 p、δ 短q δ 短 m、δ 短 n、δ 长 p、δ 长q δ 长 m、δ 长 n、D 测p D 测q D 测m D 测n ; For any δ 短i δ 长i D 测i , where i is any value of p, q, m, n, and is obtained as follows: The precision rotary spindle drives the turntable to rotate the radial stator assembly under test one revolution. During this process, the minimum distance measured at the i-th measuring point is δ. 短i The maximum distance is δ 长i ; D测i =δ 短i +δ 长i +D0,D 测i Di represents the rotation diameter of the i-th measuring point, and D0 represents the diameter of the tooling shaft; S402, Test β pq β mq β nq : For any β vq , refers to the angle between AQ and AV when AQ rotates counterclockwise, where v is any value of p, m, and n; A, Q, and V represent the rotation axis of the precision rotary spindle drive turntable, the projection points of the q-th and v-th measuring points on the same horizontal plane, respectively; the test method is as follows: Step a: Rotate the precision rotary spindle drive turntable until the minimum distance value measured at the v-th measuring point is obtained, taking this as the starting point. Rotate the precision rotary spindle drive turntable clockwise until the minimum distance value measured at the q-th measuring point is obtained, taking this as the ending point. The angle rotated by the precision rotary spindle drive turntable from the starting point to the ending point is denoted as β. vq-顺 ; Step b: Rotate the precision rotary spindle drive turntable until the minimum distance measured at the v-th measuring point is obtained, taking this as the starting point. Rotate the precision rotary spindle drive turntable counterclockwise until the minimum distance measured at the q-th measuring point is obtained, taking this as the ending point. The angle rotated by the precision rotary spindle drive turntable from the starting point to the ending point is denoted as β. vq-逆 ; β vq =β vq-逆 -(β) vq-顺+ β vq-逆 -360°) / 2; S403, Solve for L s : L s =0.5×((D) 测m ·cosβ mq + D 测n ·cosβ nq -D 测q -D 测p ·cosβ pq ) 2 +(D) 测m ·sinβ mq +D 测n ·sinβ nq -D 测p ·sinβ pq ) 2 ) 0.5 .

[0025] The second method: S100, the radial stator assembly to be tested is mounted on the precision rotary spindle drive turntable: the radial stator assembly to be tested is fixed on the precision rotary spindle drive turntable by means of V-shaped positioning blocks and clamping devices; S200, the tooling axis motion control assembly moves the tooling axis so that the tooling axis is inserted into the radial stator assembly to be tested; S300, test δ 短1 ~δ 短8 δ 长1 ~δ 短8 ; For any δ 短i δ 长i The testing method is as follows: The precision rotary spindle drives the turntable to rotate the radial stator assembly under test one revolution. During this process, the minimum distance measured at the i-th measuring point is δ. 短i The maximum distance is δ 长i ; S400, solve for the eccentricity L between the center points of the upper radial sensor and the lower radial sensor; L=0.5×[(δ 短5 +δ 长5 -δ 短7 -δ 长7 -δ 短1 -δ 长1 +δ 短3 +δ 长3 ) 2 + (δ) 短6 +δ 长6 -δ 短8 -δ 长8 -δ 短2 -δ 长2 +δ 短4 +δ 长4 ) 2 ] 0.5 .

[0026] Third, this application provides a method for testing the concentricity of the radial sensors of a magnetic levitation molecular pump, which involves testing the concentricity of the upper and lower radial sensors of the radial stator assembly under test at least twice. During each test, the position of the tooling axis is different, that is, the motion control component moves the tooling axis to different positions (this is the purpose of the tooling axis being able to move along the horizontal direction). The concentricity detection method of the radial sensor of the magnetic levitation molecular pump is used to test the concentricity of the upper radial sensor and the lower radial sensor of the radial stator assembly under test. If the detected eccentricity L is less than the eccentricity threshold [L] (e.g., 0.01216 mm), it indicates that the concentricity of the radial sensor of the magnetic levitation molecular pump is qualified; otherwise, it is unqualified. Attached Figure Description

[0027] The present application will be further described in detail below with reference to the embodiments in the accompanying drawings, but this does not constitute any limitation on the present application.

[0028] Figure 1 This is a schematic diagram of the radial stator assembly.

[0029] Figure 2 This is a three-dimensional structural diagram of a concentricity detection fixture for a radial sensor of a magnetically levitated molecular pump according to this application.

[0030] Figure 3 This is a three-dimensional structural design schematic diagram of a high-precision rotary platform component.

[0031] Figure 4 This is a schematic diagram illustrating the physical meaning of O, A, and B.

[0032] Figure 5 It is δ 短i δ 长i D 测i The physical meaning diagram.

[0033] Figure 6 It is β 42 The physical meaning diagram.

[0034] Figure 7 This is a schematic diagram of the coordinate system when the fourth and second measuring points of the upper radial sensor are used to solve for the coordinates of point O, and the eighth and sixth measuring points of the lower radial sensor are used to solve for the coordinates of point O'.

[0035] The attached diagram is described below: Upper magnetic bearing 1, upper radial sensor 2, lower radial sensor 3, lower magnetic bearing 4, first measuring point 1-1, second measuring point 1-2, third measuring point 1-3, fourth measuring point 1-4; 1000 concentricity detection fixtures for radial sensors of magnetic levitation molecular pumps; 2000 radial stator assemblies to be tested; Tooling shaft 100, tooling shaft motion control assembly 200, high-precision rotary platform assembly 300, V-shaped positioning block 301, clamping device 302, precision rotary spindle drive turntable 303. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] <Example 1> Figure 2 A three-dimensional structural diagram of a concentricity detection fixture 1000 for a radial sensor of a magnetically levitated molecular pump is shown. This fixture is used to test the concentricity of the upper and lower radial sensors of the radial stator assembly 2000 under test. It includes: a. Tooling shaft 100, which is set in a vertical position, is located at the lower part of the moving end of the tooling shaft motion control assembly 200.

[0038] b. Tooling axis motion control assembly 200, which is used to control the position of tooling axis 100.

[0039] c. High-precision rotary platform assembly 300, which serves as a placement platform for the radial stator assembly to be tested.

[0040] Figure 3 A three-dimensional structural diagram of the high-precision rotary platform assembly 300 is shown. The high-precision rotary platform assembly 300 includes: a V-shaped positioning block 301, a clamping device 302, and a precision rotary spindle drive turntable 303. The radial stator assembly to be tested is fixed on the precision rotary spindle drive turntable 303 by the V-shaped positioning block 301 and the clamping device 302. After clamping and fixing, the rotation axis of the precision rotary spindle drive turntable is coaxial with the rotation axis of the bearing seat of the radial stator assembly to be tested, and the precision rotary spindle drive turntable 303 rotates the radial stator assembly 2000 to be tested.

[0041] d. The relationship between the tooling shaft 100, the tooling shaft motion control component 200, and the precision rotary spindle drive turntable 303 is as follows: the tooling shaft 100 can be inserted into the radial stator component 2000 to be tested under the operation of the tooling shaft motion control component 200.

[0042] It should be noted that the high-precision rotary platform assembly 300 also includes an angle sensor; the angle sensor is used to measure the rotation angle of the precision rotary spindle drive turntable 303.

[0043] It should be noted that the tooling axis motion control assembly 200 has one, two, or three degrees of freedom. That is, the tooling axis 100 must be able to move vertically. Furthermore, as... Figure 1As shown, the tooling axis motion control assembly 200 can control the tooling axis 100 to move in the vertical direction and the horizontal direction (i.e., the X direction) (i.e., the tooling axis motion control assembly 200 can control the tooling axis 100 to move in two directions). In addition, the tooling axis motion control assembly 200 uses a robotic arm, which makes it possible for the tooling axis 100 to move in the vertical direction and two horizontal directions.

[0044] It should be noted that after the radial stator assembly 2000 under test is installed, the distance between the spindle of its bearing housing and the rotating spindle of the precision rotary spindle drive turntable 303 is less than 2mm. Preferably, after the radial stator assembly 2000 under test is installed, the spindle of its bearing housing coincides with the rotating spindle of the precision rotary spindle drive turntable 303. This is to ensure that when the radial stator assembly 2000 under test rotates under the drive of the precision rotary spindle drive turntable 303, it avoids collision with the tooling shaft 100.

[0045] It should be noted that during testing, the tooling shaft 100 extends into the lower radial sensor of the radial stator assembly 2000 under test, ensuring that both the upper and lower radial sensors of the radial stator assembly 2000 under test can measure data.

[0046] It should be noted that the difference between the diameter of the inner cylindrical surface of the upper radial sensor of the radial stator assembly and the outer surface diameter of the tooling shaft 100 is 2mm.

[0047] A method for detecting the concentricity of a radial sensor for a magnetically levitated molecular pump includes the following steps: S100, the radial stator assembly 2000 to be tested is installed on the test station, that is, the radial stator assembly 2000 to be tested is installed on the precision rotary spindle drive turntable 303: the radial stator assembly to be tested is fixed on the precision rotary spindle drive turntable 303 by the V-shaped positioning block 301 and the clamping device 302. S200, the tooling axis motion control assembly 200 moves the tooling axis 100 so that the tooling axis 100 is inserted into the radial stator assembly 2000 to be tested; S300, the precision rotary spindle drives the turntable 303 to rotate the radial stator assembly 2000 under test, and performs the running-in of the rotating mechanism (about 1 minute). S400, calculate the eccentricity L between the upper radial sensor and the lower radial sensor; The upper radial sensor has four measuring points, with a phase angle of 90° between the four measuring points, and these are referred to as the first to the fourth measuring points; the lower radial sensor has four measuring points, with a phase angle of 90° between the four measuring points, and these are referred to as the fifth to the eighth measuring points. The first measuring point 1-1 is the X+ measuring point, the second measuring point 1-2 is the Y+ measuring point, the third measuring point 1-3 is the X- measuring point, and the fourth measuring point 1-4 is the Y- measuring point; The fifth measuring point is X+ measuring point, the sixth measuring point is Y+ measuring point, the seventh measuring point is X- measuring point, and the eighth measuring point is Y- measuring point; For any of the first to eighth measuring points, they are all calibrated eddy current sensors, capable of measuring the distance from the tooling axis; L can be L1, L2, L3, L4, or the average of L1 and L2, or the average of L1 and L3, or the average of L1 and L4, or the average of L2 and L3, or the average of L2 and L4, or the average of L3 and L4, or the average of L1, L2, L3, or the average of L1, L2, L4, or the average of L1, L3, L4, or the average of L2, L3, L4, or the average of L1, L2, L3, L4. Where L1 is the eccentricity obtained by measuring the fourth and second measuring points of the upper radial sensor and the eighth and sixth measuring points of the lower radial sensor; Where L2 is the eccentricity obtained by measuring the fourth and second measuring points of the upper radial sensor and the seventh and fifth measuring points of the lower radial sensor; Where L3 is the eccentricity obtained by measuring the third and first measuring points of the upper radial sensor and the eighth and sixth measuring points of the lower radial sensor; Wherein, L4 is the eccentricity obtained by measuring the third and first measuring points of the upper radial sensor and the seventh and fifth measuring points of the lower radial sensor.

[0048] The eccentricity L is calculated using the p-th and q-th measuring points of the upper radial sensor and the m-th and n-th measuring points of the lower radial sensor. s The method includes the following sub-steps: S401, Test δ 短 p、δ 短q δ 短 m、δ 短 n、δ 长 p、δ 长q δ 长 m、δ 长 n、D 测p D 测q D 测m D 测n ; like Figure 4 As shown, points A, B, and O are the projection points of the rotation axis of the precision rotary spindle drive turntable, the central axis of the tooling axis, and the midpoint of the upper radial sensor on the same horizontal plane, respectively.

[0049] Figure 5 It shows δ 短i δ 长i D 测i The physical meaning of δ. 短i δ 长i D 测i, where i is any value of p, q, m, n, and is obtained as follows: The precision rotary spindle drives the turntable to rotate the radial stator assembly under test one revolution. During this process, the minimum distance measured at the i-th measuring point is δ. 短i The maximum distance is δ 长i ; D 测i =δ 短i +δ 长i +D0,D 测i Di represents the rotation diameter of the i-th measuring point, and D0 represents the diameter of the tooling shaft; S402, Test β pq β mq β nq : For any β vq , refers to the angle between AQ and AV when AQ rotates counterclockwise, where v is any value of p, m, and n; A, Q, and V represent the rotation axis of the precision rotary spindle drive turntable, the projection points of the q-th and v-th measuring points on the same horizontal plane, respectively; the test method is as follows: Test β pq β mq β nq : For any β vq , refers to the angle between AQ and AV when AQ rotates counterclockwise, where v is any value of p, m, and n; A, Q, and V represent the rotation axis of the precision rotary spindle drive turntable, the projection points of the q-th and v-th measuring points on the same horizontal plane, respectively; the test method is as follows: Step a: Rotate the precision rotary spindle drive turntable until the minimum distance value measured at the v-th measuring point is obtained, taking this as the starting point. Rotate the precision rotary spindle drive turntable clockwise until the minimum distance value measured at the q-th measuring point is obtained, taking this as the ending point. The angle rotated by the precision rotary spindle drive turntable from the starting point to the ending point is denoted as β. vq-顺 ; Step b: Rotate the precision rotary spindle drive turntable until the minimum distance measured at the v-th measuring point is obtained, taking this as the starting point. Rotate the precision rotary spindle drive turntable counterclockwise until the minimum distance measured at the q-th measuring point is obtained, taking this as the ending point. The angle rotated by the precision rotary spindle drive turntable from the starting point to the ending point is denoted as β. vq-逆 ; β vq =β vq-逆 -(β) vq-顺+ β vq-逆 -360°) / 2; S403, Solve for L s : With point A as the origin, the direction AQ points to is the positive X-axis, and AQ rotated 90° counterclockwise is the positive Y-axis; O and O' represent the coordinates of the projection points of the upper and lower radial sensors on the horizontal plane in the above-mentioned planar coordinate system. The coordinates of the projection of the q-th measuring point onto the horizontal plane are (D 测q ,0); The coordinates of the projection of the p-th measuring point onto the horizontal plane are (D 测p ·cosβ pq D 测p ·sinβ pq ); The coordinates of the projection of the m-th measuring point onto the horizontal plane are (D 测m ·cosβ mq D 测m ·sinβ mq ); The coordinates of the projection of the nth measuring point onto the horizontal plane are (D 测n ·cosβ nq D 测n ·sinβ nq ); Then we have: X O =(D 测q + D 测p ·cosβ pq ) / 2; Y O= D 测p ·sinβ pq / 2; Xo'=(D 测m ·cosβ mq + D 测n ·cosβ nq ) / 2; Yo' = (D) 测m ·sinβ mq + D 测n ·sinβ nq ) / 2; Therefore, the eccentricity L between the upper radial sensor and the lower radial sensor can be determined as follows: L = ((Xo' - Xo)) 2 +(Yo'- Yo) 2 ) 0.5 .

[0050] Taking the calculation of eccentricity using the fourth and second measuring points of the upper radial sensor and the eighth and sixth measuring points of the lower radial sensor as an example.

[0051] First, measure β 42 β82 β 62 The projections of the i-th and j-th measuring points onto the horizontal plane are points i and j, respectively, and β ij This refers to the angle between Aj and Ai when Aj rotates counterclockwise. any β ij The testing method is: Step a: When the distance measured at the i-th measuring point is at its minimum value, the precision rotary spindle drives the turntable 303 to rotate clockwise until the distance measured at the j-th measuring point is at its minimum value. The angle through which the precision rotary spindle drives the turntable 303 rotates is denoted as β. ij-顺 ; Step b: When the minimum distance is measured at the i-th measuring point, the precision rotary spindle drives the turntable 303 to rotate counterclockwise until the minimum distance is measured at the j-th measuring point. The angle through which the precision rotary spindle drives the turntable 303 rotates is denoted as β. ij-逆 ; β ij =β ij-逆 -(β) ij-顺+ β ij-逆 -360°) / 2.

[0052] By rotating clockwise and counterclockwise, measurement errors are reduced.

[0053] The above method can measure β 42 β 82 β 62 .

[0054] Then, the coordinates of point O are solved using the fourth and second measuring points of the upper radial sensor, and the coordinates of point O' are solved using the eighth and sixth measuring points of the lower radial sensor. The method for calculating the coordinates of point O using the datasets from the fourth and second measurement points is as follows: like Figure 7 As shown, with point A as the origin of the coordinate system, the direction in which point A points to the projection of the second measuring point on the horizontal plane is the positive X-direction, and the positive Y-direction is the direction rotated 90° counterclockwise from the aforementioned positive X-direction. The coordinates of the projection of the second measuring point onto the horizontal plane are (D) 测2 ,0); The coordinates of the projection of the fourth measuring point onto the horizontal plane are (D) 测4 ·cosβ 42 D 测4 ·sinβ 42 ); have: X O =(D 测2 + D 测4 ·cosβ 42 ) / 2; Y O=D 测4 ·sinβ 42 / 2; The coordinates of the projection of the eighth measuring point onto the horizontal plane are (D) 测8 ·cosβ 82 D 测8 ·sinβ 82 ); The coordinates of the projection of the sixth measuring point onto the horizontal plane are (D) 测6 ·cosβ 62 D 测6 ·sinβ 62 ); have: Xo'=(D 测8 ·cosβ 82 + D 测6 ·cosβ 62 ) / 2; Yo' = (D) 测8 ·sinβ 82 + D 测6 ·sinβ 62 ) / 2; Therefore, the eccentricity L between the upper radial sensor and the lower radial sensor can be determined as follows: L = ((Xo' - Xo)) 2 +(Yo'- Yo) 2 ) 0.5 .

[0055] It should be noted that, for L, the second simplified algorithm can also be used: With point A as the origin of the coordinate system, the detection direction of the third measuring point 1-3 pointing to the first measuring point 1-1 is the positive X direction, and the detection direction of the fourth measuring point 1-4 pointing to the second measuring point 1-2 is the positive Y direction. The coordinates of point O can be approximately solved using the following formula: Xo≈D 测1 / 2-D 测3 / 2=(δ 短1 +δ 长1 -δ 短3 -δ 长3 ) / 2,Yo≈D 测2 / 2-D 测4 / 2=(δ 短2 +δ 长2 -δ 短4 -δ 长4 ) / 2.

[0056] Correspondingly, point O' is the projection of the midpoint of the lower radial sensor onto the horizontal plane. Therefore: With point A as the origin, the coordinates of point O' can be approximately solved using the following formula: Xo'≈D 测5 / 2-D 测7 / 2=(δ 短5 +δ 长5 -δ 短7 -δ 长7 ) / 2,Yo'≈D 测6 / 2-D 测8 / 2=(δ 短6 +δ 长6 -δ 短8 -δ 长8 ) / 2.

[0057] Therefore, the eccentricity L between the upper radial sensor and the lower radial sensor can be determined as follows: L = ((Xo' - Xo)) 2 +(Yo'- Yo) 2 ) 0.5 .

[0058] In other words, when detecting the concentricity of a radial sensor for a magnetic levitation molecular pump, the tooling shaft remains stationary. The test can be completed simply by rotating the precision rotary spindle to drive the turntable to rotate synchronously and cause the radial stator assembly under test to rotate.

[0059] In actual testing, the concentricity detection of a radial sensor of a magnetic levitation molecular pump is performed multiple times. That is, when the tooling shaft motion control component 200 moves the tooling shaft to different positions, the concentricity of the radial sensor of the magnetic levitation molecular pump is detected separately. If the detected eccentricity L is less than the eccentricity [L] threshold each time, it indicates that the concentricity of the radial sensor of the magnetic levitation molecular pump meets the requirements; otherwise, it does not meet the requirements.

[0060] The meanings of the physical symbols used in this application are explained below: A, B, O, and O' represent the projection points of the rotation axis of the precision rotary spindle drive turntable, the central axis of the tooling axis, the midpoint of the upper radial sensor, and the midpoint of the lower radial sensor onto the same horizontal plane, respectively.

[0061] L1 represents the eccentricity calculated using the fourth and second measuring points of the upper radial sensor and the eighth and sixth measuring points of the lower radial sensor.

[0062] L2 represents the eccentricity calculated using the fourth and second measuring points of the upper radial sensor and the seventh and fifth measuring points of the lower radial sensor.

[0063] L3 represents the eccentricity calculated using the third and first measuring points of the upper radial sensor and the eighth and sixth measuring points of the lower radial sensor.

[0064] L4 represents the eccentricity calculated using the third and first measuring points of the upper radial sensor and the seventh and fifth measuring points of the lower radial sensor.

[0065] L is the eccentricity between the upper radial sensor and the lower radial sensor.

[0066] (Xo, Yo) and (Xo', Yo') represent the coordinates of O and O' in the same coordinate system, respectively.

[0067] p, q, m, n are the parameters of the measuring point, such as: p=4, q=2 or p=2, q=4 or p=3, q=1 or p=1, q=3, m=8, n=6 or m=6, n=8 or m=7, n=5 or m=5, n=7.

[0068] L s L1, L2, L3, or L4 represents the eccentricity calculated by measuring the p and q points of the upper radial sensor and the m and n points of the lower radial sensor.

[0069] δ 短 p、δ 短q δ 短 m、δ 短 n、δ 短i These represent the minimum distance values ​​measured at measuring points p, q, m, n, and i when the precision rotary spindle drives the turntable to rotate one revolution with the radial stator assembly under test. δ 长 p、δ 长q δ 长 m、δ 长 n、δ 长i These represent the maximum distance values ​​measured at measuring points p, q, m, n, and i respectively, when the precision rotary spindle drives the turntable to rotate one revolution with the radial stator assembly under test. D 测p D 测q D 测m D 测n D 测i These represent the rotation diameters of the p-th, q-th, m-th, n-th, and i-th measuring points when the precision rotary spindle drives the turntable to rotate with the radial stator assembly under test. D0 represents the diameter of the tooling shaft.

[0070] B vq : The counterclockwise rotation angle from the q-th measuring point to the v-th measuring point, specifically, refers to the angle between AQ and AV when rotated counterclockwise; A, Q, and V represent the rotation axis of the precision rotary spindle drive turntable, the projection points of the q-th measuring point, and the v-th measuring point on the same horizontal plane, respectively.

[0071] β vq-顺Let β be the starting point, where the distance measured at the v-th measuring point is minimized by rotating the precision rotary spindle drive turntable. The turntable then rotates clockwise until the distance measured at the q-th measuring point is minimized, which is the ending point. The angle β traversed by the precision rotary spindle drive turntable from the starting point to the ending point is denoted as β. vq-顺 .

[0072] β vq-逆 Let β be the starting point, where the distance measured at the v-th measuring point is minimized by rotating the precision rotary spindle drive turntable. The turntable then rotates counter-clockwise until the distance measured at the q-th measuring point is minimized, which is the ending point. The angle β traversed by the precision rotary spindle drive turntable from the starting point to the ending point is denoted as β. vq-逆 .

[0073] The above-described embodiments are preferred embodiments of this application and are only used to facilitate the illustration of this application. They are not intended to limit this application in any way. Any person with ordinary knowledge in the art can make equivalent embodiments by making partial modifications or alterations to the technical content disclosed in this application without departing from the scope of the technical features of this application. Such equivalent embodiments are still within the scope of the technical features of this application.

Claims

1. A concentricity testing fixture for radial sensors of a magnetically levitated molecular pump, used to test the concentricity of the upper and lower radial sensors of the radial stator assembly under test; Its features are, include: a. Tooling shaft, which is set in a vertical position and is located at the lower part of the moving end of the tooling shaft motion control assembly; b. Tooling axis motion control assembly, which is used to control the position of the tooling axis; the tooling axis motion control assembly can control the tooling axis to move in the vertical direction; c, High-precision rotary platform assembly, which serves as a placement platform for the radial stator assembly under test; The high-precision rotary platform assembly includes: a V-shaped positioning block, a clamping device, and a precision rotary spindle drive turntable; The V-shaped positioning block and the clamping device are used to fix the radial stator assembly to be tested on the precision rotary spindle drive turntable. The precision rotary spindle drive turntable is used to drive the radial stator assembly under test to rotate. d. The tooling axis motion control component can control the tooling axis to enter the radial stator assembly to be measured.

2. The concentricity detection fixture for a radial sensor of a magnetically levitated molecular pump according to claim 1, characterized in that, The high-precision rotary platform assembly also includes: an angle sensor; the angle sensor is used to measure the rotation angle of the precision rotary spindle-driven turntable.

3. The concentricity detection fixture for a radial sensor of a magnetically levitated molecular pump according to claim 1, characterized in that, The rotation axis of the precision rotary spindle drive turntable is coaxial with the rotation axis of the bearing housing of the radial stator assembly to be tested.

4. The concentricity detection fixture for a radial sensor of a magnetically levitated molecular pump according to claim 1, characterized in that, The tooling axis motion control assembly can also control the tooling axis to move in the horizontal direction.

5. The concentricity detection fixture for a radial sensor of a magnetically levitated molecular pump according to claim 1, characterized in that, The difference between the diameter of the inner cylindrical surface of the upper radial sensor of the radial stator assembly and the diameter of the outer surface of the tooling shaft is 2 mm.

6. The concentricity detection fixture for a radial sensor of a magnetically levitated molecular pump according to claim 1, characterized in that, The tooling axis motion control assembly can control the tooling axis to extend into the lower radial sensor of the radial stator assembly under test, so that both the upper and lower radial sensors of the radial stator assembly under test can measure data.

7. A method for detecting the concentricity of a radial sensor of a magnetic levitation molecular pump, wherein a concentricity detection fixture for a radial sensor of a magnetic levitation molecular pump as described in any one of claims 1 to 6 is used to test the concentricity of the upper radial sensor and the lower radial sensor of the radial stator assembly under test. The upper radial sensor has four measuring points, with a phase angle of 90° between the four measuring points, denoted as the first to fourth measuring points; the lower radial sensor has four measuring points, with a phase angle of 90° between the four measuring points, denoted as the fifth to eighth measuring points; the first measuring point is the X+ measuring point, the second measuring point is the Y+ measuring point, the third measuring points 1-3 are the X- measuring points, the fourth measuring point is the Y- measuring point; the fifth measuring point is the X+ measuring point, the sixth measuring point is the Y+ measuring point, the seventh measuring point is the X- measuring point, and the eighth measuring point is the Y- measuring point; Its features are, Includes the following steps: S100, the radial stator assembly to be tested is mounted on the precision rotary spindle drive turntable: the radial stator assembly to be tested is fixed on the precision rotary spindle drive turntable by means of V-shaped positioning blocks and clamping devices; S200, the tooling axis motion control assembly moves the tooling axis so that the tooling axis is inserted into the radial stator assembly to be tested; S300, test 短1 ~d 短8 、d 长1 ~d 短8 ; For any δ 短i δ 长i The testing method is as follows: The precision rotary spindle drives the turntable to rotate the radial stator assembly under test one revolution. During this process, the minimum distance measured at the i-th measuring point is δ. 短i The maximum distance is δ 长i ; S400, solve for the eccentricity L between the center points of the upper radial sensor and the lower radial sensor; L=0.5×[(δ 短5 +d 长5 -d 短7 -d 长7 -d 短1 -d 长1 +d 短3 +d 长3 ) 2 +(d) 短6 +d 长6 -d 短8 -d 长8 -d 短2 -d 长2 +d 短4 +d 长4 ) 2 ] 0.5 。 8. A method for detecting the concentricity of a radial sensor of a magnetic levitation molecular pump, wherein the concentricity of the upper radial sensor and the lower radial sensor of the radial stator assembly under test is tested using a concentricity detection fixture for a magnetic levitation molecular pump radial sensor as described in any one of claims 1 to 6. The upper radial sensor has four measuring points, with a phase angle of 90° between the four measuring points, denoted as the first to fourth measuring points; the lower radial sensor has four measuring points, with a phase angle of 90° between the four measuring points, denoted as the fifth to eighth measuring points; the first measuring point is the X+ measuring point, the second measuring point is the Y+ measuring point, the third measuring points 1-3 are the X- measuring points, the fourth measuring point is the Y- measuring point; the fifth measuring point is the X+ measuring point, the sixth measuring point is the Y+ measuring point, the seventh measuring point is the X- measuring point, and the eighth measuring point is the Y- measuring point; Its features are, Includes the following steps: S100, the radial stator assembly to be tested is mounted on the precision rotary spindle drive turntable: the radial stator assembly to be tested is fixed on the precision rotary spindle drive turntable by means of V-shaped positioning blocks and clamping devices; S200, the tooling axis motion control assembly moves the tooling axis so that the tooling axis is inserted into the radial stator assembly to be tested; S300, solve for the eccentricity L between the center points of the upper radial sensor and the lower radial sensor; L can be any one or the average of any two of L1, L2, L3, and L4, or the average of any three or four of them. L1 is the eccentricity calculated using the fourth and second measuring points of the upper radial sensor and the eighth and sixth measuring points of the lower radial sensor. L2 is the eccentricity calculated using the fourth and second measuring points of the upper radial sensor and the seventh and fifth measuring points of the lower radial sensor. L3 is the eccentricity calculated by using the third and first measuring points of the upper radial sensor and the eighth and sixth measuring points of the lower radial sensor. L4 is the eccentricity calculated using the third and first measuring points of the upper radial sensor and the seventh and fifth measuring points of the lower radial sensor. The eccentricity L is calculated by using the p-th and q-th measuring points of the upper radial sensor and the m-th and n-th measuring points of the lower radial sensor. s The method includes the following sub-steps: S401, test d 短 p、d 短q 、d 短 m、d 短 n、d 长 p、d 长q 、d 长 m、d 长 n、D 测p 、D 测q 、D 测m 、D 测n ; For any δ 短i δ 长i D 测i , where i is any value of p, q, m, n, and is obtained as follows: The precision rotary spindle drives the turntable to rotate the radial stator assembly under test one revolution. During this process, the minimum distance measured at the i-th measuring point is δ. 短i The maximum distance is δ 长i ; D 测i =δ 短i +δ 长i +D0,D 测i Di represents the rotation diameter of the i-th measuring point, and D0 represents the diameter of the tooling shaft; S402, test b pq 、b mq 、b nq : For any β vq , refers to the angle between AQ and AV when AQ rotates counterclockwise, where v is any value of p, m, and n; A, Q, and V represent the rotation axis of the precision rotary spindle drive turntable, the projection points of the q-th and v-th measuring points on the same horizontal plane, respectively; the test method is as follows: Step a: Rotate the precision rotary spindle drive turntable until the minimum distance value measured at the v-th measuring point is obtained, taking this as the starting point. Rotate the precision rotary spindle drive turntable clockwise until the minimum distance value measured at the q-th measuring point is obtained, taking this as the ending point. The angle rotated by the precision rotary spindle drive turntable from the starting point to the ending point is denoted as β. vq-顺 ; Step b: Rotate the precision rotary spindle drive turntable until the minimum distance measured at the v-th measuring point is obtained, taking this as the starting point. Rotate the precision rotary spindle drive turntable counterclockwise until the minimum distance measured at the q-th measuring point is obtained, taking this as the ending point. The angle rotated by the precision rotary spindle drive turntable from the starting point to the ending point is denoted as β. vq-逆 ; β vq =β vq-逆 -（β vq-顺+ β vq-逆 -360°） / 2； S403, Solve for L s : L s =0.5×((D 测m ·cosβ mq + D 测n ·cosβ nq -D 测q -D 测p ·cosβ pq ) 2 +(D) 测m ·sinβ mq + D 测n ·sinβ nq -D 测p ·sinβ pq ) 2 ) 0.5 。 9. The method for detecting the concentricity of a radial sensor for a magnetically levitated molecular pump according to claim 8, characterized in that, The S200 also includes: a precision rotary spindle drive turntable that rotates the radial stator assembly to be tested to run-in the rotating mechanism.

10. A method for detecting the concentricity of a radial sensor for a magnetically levitated molecular pump, characterized in that, The concentricity of the upper and lower radial sensors of the radial stator assembly under test shall be tested at least twice. During each test, the position of the tooling axis is different, that is, the motion control component moves the tooling axis to different positions. The concentricity detection method of the radial sensor of the magnetic levitation molecular pump as described in claim 7, 8 or 9 is used to test the concentricity of the upper radial sensor and the lower radial sensor of the radial stator assembly under test. If the detected eccentricity L is less than the eccentricity threshold [L] each time, it indicates that the concentricity of the radial sensor of the magnetic levitation molecular pump is qualified; otherwise, it is unqualified.

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