Ball screw spiral raceway waviness detection device based on spectrum confocal sensor

Abstract

The invention discloses a ball screw spiral raceway waviness detection device based on a spectral confocal sensor, and the device comprises a supporting platform which is used for supporting a driving screw, a detected screw and an air floating platform; the first servo motor is connected with the driving lead screw; the second servo motor is connected with the tested lead screw; a distance acquisition unit; a spectral confocal sensor; the air floating platform is used for connecting the dragging mechanism, the adjusting mechanism and the detachable connecting seat; the dragging mechanism is used for being aligned with a tested roller path of the tested lead screw and dragging the air floating platform to move; the adjusting mechanism is used for adjusting the incident angle of the light beam of the spectral confocal sensor; and the detachable connecting seat can be connected with and separated from the driving lead screw, so that the distance value returned by the spectrum confocal sensor reaches the maximum value. According to the invention, rapid and continuous detection of the waviness of the spiral raceway of the ball screw is realized.

Description

Technical Field

[0001] This invention belongs to the field of fine-tuning measurement and optical detection technology, and in particular, it is a ball screw helical raceway waviness detection device based on a spectral confocal sensor. Background Technology

[0002] As a core component of feed motion systems, ball screw assemblies are widely used in high-precision equipment such as humanoid robots, electric vehicles, and CNC machine tools. Their thread profile exhibits a cylindrical helical structure with equal pitch in three-dimensional space, making the machining process more complex than external cylindrical grinding or conventional surface finishing. Regardless of whether grinding or rotary cutting is used, due to machine tool vibration and the rigidity of the machining system, a certain degree of waviness error is unavoidable on the thread profile surface. Waviness not only affects the frictional characteristics and preload stability of the screw assembly but also causes performance degradation such as system noise and vibration. Therefore, high-precision detection of the waviness of the ball screw raceway helix is ​​of great significance for optimizing machining processes, improving assembly quality, and conducting in-depth research on the operating performance of the screw assembly.

[0003] Traditional surface waviness measurement primarily relies on contact methods, where a probe slides along a predetermined trajectory under a constant contact force to collect surface height deviations. However, to avoid probe bounce, this method typically operates at a low speed and only supports linear or two-dimensional trajectory measurements, limiting its application in efficient continuous measurement of complex surfaces. In summary, existing methods suffer from slow measurement speeds, incomplete profile acquisition, and trajectory deviations when dealing with helical profile structures. Therefore, there is an urgent need to develop a high-precision measurement scheme capable of continuously measuring the waviness of the entire raceway helical profile. Summary of the Invention

[0004] The purpose of this invention is to provide a ball screw helical raceway waviness detection device based on a spectral confocal sensor, so as to achieve rapid and continuous detection of ball screw helical raceway waviness.

[0005] The technical solution to achieve the purpose of this invention is as follows:

[0006] A ball screw helical raceway waviness detection device based on a spectral confocal sensor includes:

[0007] Support platform, used to support the drive screw, the tested screw, and the air-bearing platform;

[0008] The first servo motor is used to drive the lead screw to rotate;

[0009] The second servo motor is used to drive the measured lead screw to rotate.

[0010] The distance acquisition unit is used to acquire horizontal distance data of the surface profile of the helical raceway in real time.

[0011] A spectral confocal sensor is used to acquire vertical distance data of the surface profile of the helical raceway in real time.

[0012] Air-floating platform, used to connect the towing mechanism, the adjustment mechanism and the detachable connecting seat;

[0013] The dragging mechanism is used to align the raceway of the lead screw being tested. When the second servo motor drives the lead screw to rotate, the air-bearing platform moves horizontally along the axis parallel to the lead screw being tested under the dragging of the dragging mechanism.

[0014] The adjustment mechanism is used to adjust the incident angle of the beam of the spectral confocal sensor so that the beam of the spectral confocal sensor is perpendicular to the normal cross-sectional profile of the helical raceway of the lead screw being measured.

[0015] The detachable connector can be connected and disconnected from the drive screw. When connected to the drive screw, the first servo motor drives the drive screw to rotate, thereby adjusting the position of the air-bearing platform so that the distance value returned by the spectral confocal sensor reaches its maximum.

[0016] The significant advantages of this invention compared to existing technologies are:

[0017] The dragging mechanism designed in this invention allows the air-bearing platform to move as the lead screw rotates, thereby causing the spectral confocal sensor on the air-bearing platform to move horizontally. At this time, the light spot of the spectral confocal sensor collects data along the spiral line of the lead screw, solving the problem that traditional contact profilometers only support linear or two-dimensional profile measurements and cannot collect spiral profiles. The adjustment mechanism of this invention can adjust the incident angle of the spectral confocal sensor beam, ensuring that the beam of the spectral confocal sensor is perpendicular to the spiral raceway of the lead screw. This minimizes measurement errors caused by incident angle deviations. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of a ball screw helical raceway waviness detection device based on a spectral confocal sensor.

[0019] Figure 2 A schematic diagram of the adjustment mechanism.

[0020] Figure 3 This is a schematic diagram of the drag mechanism.

[0021] Figure 4 This is a schematic diagram of a detachable connector structure. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0023] Combination Figure 1This embodiment of a ball screw helical raceway waviness detection device based on a spectral confocal sensor includes a headstock 1, a first servo motor 2, a second servo motor 3, an air-bearing platform 4, a dragging mechanism 5, a tailstock 7, a detachable connecting seat 8, an adjustment mechanism 9, a spectral confocal sensor 10, a linear grating ruler 11, a marble bed 12, and a drive screw 13.

[0024] The first servo motor 2 is installed on the left side of the marble bed 12 (as a support platform) and connected to the drive screw 13 via a flat belt, thereby rotating the drive screw 13. The second servo motor 3 is installed on the left side of the marble bed and connected to the headstock 1 via a flat belt, thereby driving the headstock 1 turntable to rotate. The headstock 1 is fixed to one side of the upper surface of the marble bed 12, and the tailstock 7 is located on the other side of the upper surface of the marble bed 12. The tailstock 7 can slide on the marble bed 12 and can be adjusted and fixed according to the length of the lead screw being measured. The headstock 1 and the tailstock 7 cooperate to support the lead screw 6 being measured, and the lead screw 6 being measured and the headstock 1 turntable are fixed by clamping fixtures. The air-bearing platform 4 is installed on the marble bed 12.

[0025] The dragging mechanism 5 is mounted on the air-bearing platform 4 and can adjust the position of the dragging head to align it with the raceway of the lead screw 6 being measured. When the second servo motor 3 drives the lead screw 6 to rotate, the air-bearing platform 4 moves horizontally along the axis parallel to the lead screw 6 under the dragging of the dragging mechanism 5. The adjustment mechanism 9 is mounted on the air-bearing platform 4 and can adjust the incident angle of the spectral confocal sensor beam to ensure that the beam of the spectral confocal sensor is perpendicular to the normal cross-sectional profile of the helical raceway of the lead screw 6 being measured. This minimizes the measurement error caused by the incident angle deviation. The spectral confocal sensor 10 is mounted on the adjustment mechanism 9, and the measured data can be converted into vertical distance data of the surface profile of the helical raceway of the lead screw 6 being measured. The linear grating ruler 11 is mounted on the marble bed 12, and its probe is mounted on the air-bearing platform 4. The measured data can be converted into horizontal distance data of the surface profile of the helical raceway of the lead screw 6 being measured. The drive screw 13 is mounted on the marble bed 12 through two bearing seats and is connected to the first servo motor 2 via a flat belt. The detachable connector 8 is mounted on the air-float platform 4. When it is connected to the drive screw 13, the first servo motor 2 rotates, driving the air-float platform 4 to move horizontally and adjust its position. When it is necessary to collect the waviness of the ball screw helical raceway, the detachable connector 8 is disengaged from the drive screw 13.

[0026] Furthermore, combined Figure 2The adjustment mechanism 9 includes a third servo motor 9-1, a reducer 9-2, a first connecting plate 9-3, a two-dimensional fine-tuning manual translation platform 9-4, a spectral confocal sensor clamping plate 9-5, a two-dimensional coarse-tuning manual translation platform 9-6, an L-shaped plate 9-7, a second connecting plate 9-8, a turntable 9-9, and a second connecting plate 9-10.

[0027] The adjustment mechanism 9 is mounted on the air-float platform 4 via a reducer 9-2. The third servo motor 9-1 is mounted on the lower surface of the reducer 9-2 and drives the first connecting plate 9-3 to rotate radially relative to the lead screw 6 being measured. The rotation angle is equal to the helix angle of the lead screw 6 being measured, so that the scanning plane of the spectral confocal sensor is tangent to the helix of the lead screw 6 being measured. The first connecting plate 9-3 is mounted on the upper surface of the reducer 9-2. The two-dimensional coarse adjustment manual translation platform 9-6 is mounted on the first connecting plate 9-3 and can move radially and axially relative to the lead screw 6 being measured. When moving radially relative to the lead screw 6 being measured, the distance between the spectral confocal sensor 10 and the upper generatrix of the lead screw 6 being coarsely adjusted. When the distance value returned by the spectral confocal sensor 10 is minimized, it indicates that the light spot is located on the upper generatrix of the lead screw 6 being measured. When moving axially relative to the lead screw 6 being measured, the beam of the spectral confocal sensor 10 is coarsely adjusted to the raceway being measured. The L-shaped plate 9-7 is mounted on the two-dimensional coarse adjustment manual translation platform 9-6. The second connecting plate 9-8 is mounted on the L-shaped plate 9-7. The turntable 9-9 is mounted on the second connecting plate 9-8 and can rotate relative to the vertical centerline of the normal cross-sectional profile of the raceway of the lead screw 6 being measured, so as to adjust the contact angle direction line of the beam of the spectral confocal sensor 10 parallel to the normal cross-sectional profile of the raceway of the lead screw 6 being measured. The second connecting plate 9-10 is mounted on the turntable 9-9. The two-dimensional fine-tuning manual translation platform 9-4 is mounted on the second connecting plate 9-10 and can move relative to the contact angle direction line of the normal cross-sectional profile of the raceway of the lead screw 6 being measured and perpendicular to the contact angle direction line of the normal cross-sectional profile of the raceway of the lead screw 6 being measured. When moving relative to the contact angle direction line of the normal cross-sectional profile of the raceway of the lead screw 6 being measured, the spectral confocal sensor 10 is adjusted to be within the working distance. The working distance of the spectral confocal sensor used in this invention is 19.1±0.5mm. When the contact angle direction line of the raceway normal section profile perpendicular to the lead screw 6 being measured moves, the position of the light spot of the spectral confocal sensor 10 on the normal section profile of the raceway is adjusted so that the light beam of the spectral confocal sensor 10 is perpendicular to the normal section profile of the raceway being measured. The spectral confocal sensor clamping plate 9-5 is mounted on the two-dimensional fine-tuning manual translation platform 9-4.

[0028] Furthermore, combined Figure 3The dragging mechanism 5 includes a dragging mechanism mounting plate 5-1, a first linear guide rail 5-2, a second linear guide rail 5-3, a guide frame 5-4, a sleeve 5-5, a bolt 5-6, a dragging rod 5-7, a dragging frame 5-8, a compression spring 5-9, a one-dimensional manual translation platform 5-10, and a mounting plate 5-11.

[0029] The dragging mechanism 5 is mounted on the air-floating platform 4 via a dragging mechanism mounting plate 5-1. The first linear guide rail 5-2 and the second linear guide rail 5-3 are fixed parallel to each other on the dragging mechanism mounting plate 5-1. The guide frame 5-4 is fixed on the dragging mechanism mounting plate 5-1. The mounting plate 5-11 is mounted on the first linear guide rail 5-2 and the second linear guide rail 5-3, and can slide horizontally along the first linear guide rail 5-2 and the second linear guide rail 5-3 in the horizontal radial direction of the lead screw 6 being measured. The bolt 5-6 passes through the guide groove of the guide frame 5-4 and is mounted on the mounting plate 5-11. The sleeve 5-5 is fitted onto the bolt 5-6 and passes through the guide groove of the guide frame 5-4. The compression spring 5-9 is fitted onto the sleeve 5-5 and is located between the guide frame 5-4 and the mounting plate 5-11. The one-dimensional manual translation platform 5-10 is fixed on the mounting plate 5-11 and can move parallel to the axial direction of the lead screw 6 being measured, so that the drag head of the drag rod 5-7 is aligned with the raceway of the lead screw 6 being measured. The drag frame 5-8 is fixed on the one-dimensional manual translation platform 5-10. The drag rod 5-7 is installed in the guide groove of the drag frame 5-8, can slide along the guide groove, and is fixed by screws.

[0030] Furthermore, in combination Figure 4 The detachable connecting seat 8 includes a mounting base 8-1, a connecting seat compression spring 8-2, a nut 8-3, and a guide rod 8-4. The detachable connecting seat 8 is mounted on the air-floating platform 4 via the mounting base 8-1. The nut 8-3 is threaded onto the mounting base 8-1, and the guide rod 8-4 is a smooth rod that passes through the nut 8-3 and the mounting base 8-1. The connecting seat compression spring 8-2 is installed between the mounting base 8-1 and the guide rod 8-4. The connecting seat compression spring 8-2 presses the tip of the guide rod 8-4 into the raceway of the drive screw 13. By adjusting the position of the nut 8-3, the position of the guide rod 8-4 is adjusted, allowing the guide rod 8-4 to move vertically, thereby controlling the disengagement and connection of the tip of the guide rod 8-4 with the drive screw 13.

[0031] Furthermore, the specific detection process of the ball screw helical raceway waviness detection device based on a spectral confocal sensor of the present invention is as follows:

[0032] Step 1: Install the lead screw to be tested

[0033] The lead screw 6 under test is mounted on the testing device via the head frame 1 and the tail frame 7, and the lead screw 6 under test and the turntable of the head frame 1 are fixed by a chuck.

[0034] Step 2: Adjust the adjustment mechanism

[0035] Step 2-1: Align the helix angle and position the upper busbar

[0036] First, drive the third servo motor 9-1 to rotate the first connecting plate 9-3 relative to the horizontal radial direction of the lead screw 6 being measured. The rotation angle is equal to the helix angle of the lead screw 6 being measured, so that the scanning plane of the spectral confocal sensor is tangent to the helix of the lead screw 6 being measured. Next, adjust the lower moving platform of the two-dimensional coarse adjustment manual translation platform 9-6 to move back and forth along the horizontal radial direction of the lead screw being measured. When the distance value returned by the spectral confocal sensor 10 is the minimum, it indicates that the light spot is located on the upper generatrix of the lead screw 6 being measured.

[0037] Step 2-2: Locating the lowest point of the axial section

[0038] Next, the detachable connecting seat 8 is connected to the drive screw 13, driving the first servo motor 2 to move the air-floating platform 4. When the distance value returned by the spectral confocal sensor 10 reaches its maximum, it indicates that the light spot is located at the lowest point of the axial cross-sectional profile of the raceway of the measured screw 6.

[0039] Steps 2-3: Rotate the turntable so that the beam of the spectral confocal sensor is parallel to the contact angle direction line of the normal cross-sectional profile of the raceway of the lead screw 6 being measured.

[0040] The turntable 9-9 is rotated a certain angle relative to the vertical centerline of the raceway normal section profile of the lead screw 6 being measured, and then fixed. The rotation angle of the turntable 9-9 is equal to the contact angle of the raceway normal section. At this time, the beam of the spectral confocal sensor is parallel to the contact angle direction line of the raceway normal section profile of the lead screw 6 being measured.

[0041] Steps 2-4: Vertical beam adjustment

[0042] Adjust the upper moving platform of the two-dimensional coarse adjustment manual translation platform 9-6 to move it axially relative to the lead screw 6 being measured, so that the beam of the spectral confocal sensor moves to the raceway of the lead screw 6 being measured. Adjust the lower moving platform of the two-dimensional fine adjustment manual translation platform 9-4, moving it perpendicular to the contact angle direction line of the normal cross-sectional profile of the raceway of the lead screw 6 being measured, so that the spot of the spectral confocal sensor 10 moves along the normal cross-sectional profile of the raceway. When the distance value returned by the spectral confocal sensor 10 reaches its maximum, the beam of the spectral confocal sensor 10 is perpendicular to the normal cross-sectional profile of the raceway being measured. Adjust the upper moving platform of the two-dimensional fine adjustment manual translation platform 9-4 to move the spectral confocal sensor 10 along the contact angle direction line of the normal cross-sectional profile of the raceway of the lead screw 6 being measured, adjusting the spectral confocal sensor 10 to be within the working distance. The working distance of the spectral confocal sensor used in this invention is 19.1±0.5mm.

[0043] Step 3: Adjust the drag mechanism

[0044] Adjust the one-dimensional manual translation platform 5-10 to move relative to the axis of the lead screw 6 being measured, so that the drag head of the drag rod 5-7 is aligned with the raceway of the lead screw 6 being measured. Adjust the position of the drag rod 5-7 by adjusting the bolt 5-6. The drag head of the drag rod 5-7 is pushed into the raceway being measured by the compression spring 5-9.

[0045] Step 4: Start the measurement

[0046] The detachable connecting seat 8 is disengaged from the drive screw 13. The second servo motor 3 is controlled to rotate, which in turn drives the turntable of the headstock 1 via a flat belt, thereby rotating the measured screw 6. The drag mechanism 5 synchronously drives the air-bearing platform 4 to perform horizontal linear motion, causing the measuring spot of the spectral confocal sensor 10 to move continuously along the helical profile of the raceway. During the measurement process, the spectral confocal sensor 10 collects the vertical distance data of the helical raceway surface profile in real time, and the linear grating ruler 11 collects the horizontal distance data of the helical raceway surface profile in real time. The vertical and horizontal distance data constitute the two-dimensional data of the helical raceway surface profile. Processing the two-dimensional data of the raceway surface profile according to ISO 4287 yields the helical raceway waviness of the ball screw.

Claims

1. A ball screw helical raceway waviness detection device based on a spectral confocal sensor, characterized in that, include: Support platform, used to support the drive screw, the tested screw, and the air-bearing platform; The first servo motor is used to drive the lead screw to rotate; The second servo motor is used to drive the measured lead screw to rotate. The distance acquisition unit is used to acquire horizontal distance data of the surface profile of the helical raceway in real time. A spectral confocal sensor is used to acquire vertical distance data of the surface profile of the helical raceway in real time. Air-floating platform, used to connect the towing mechanism, the adjustment mechanism and the detachable connecting seat; The dragging mechanism is used to align the raceway of the lead screw being tested. When the second servo motor drives the lead screw to rotate, the air-bearing platform moves horizontally along the axis parallel to the lead screw being tested under the dragging of the dragging mechanism. The adjustment mechanism is used to adjust the incident angle of the beam of the spectral confocal sensor so that the beam of the spectral confocal sensor is perpendicular to the normal cross-sectional profile of the helical raceway of the lead screw being measured. The detachable connector can be connected and disconnected from the drive screw. When connected to the drive screw, the first servo motor drives the drive screw to rotate, thereby adjusting the position of the air-bearing platform so that the distance value returned by the spectral confocal sensor reaches its maximum.

2. The ball screw helical raceway waviness detection device based on a spectral confocal sensor according to claim 1, characterized in that, The adjustment mechanism includes: The third servo motor is used to drive the first connecting plate to rotate horizontally radially relative to the lead screw being measured. The rotation angle is equal to the helix angle of the lead screw being measured, so that the scanning plane of the spectral confocal sensor is tangent to the helix of the lead screw being measured. The two-dimensional coarse adjustment translation platform connected to the first connecting plate can move horizontally and radially relative to the lead screw being measured to coarsely adjust the distance between the spectral confocal sensor and the upper generatrix of the lead screw being measured, so that the light spot is located on the upper generatrix of the lead screw being measured, and coarsely adjust the beam of the spectral confocal sensor onto the raceway being measured. The turntable connected to the two-dimensional coarse adjustment translation platform can rotate relative to the vertical centerline of the normal cross-sectional profile of the normal raceway of the measured lead screw, so as to adjust the contact angle direction line of the spectral confocal sensor beam parallel to the normal cross-sectional profile of the raceway of the measured lead screw. The two-dimensional fine-tuning translation platform connected to the turntable can move relative to the contact angle direction line of the normal cross-sectional profile of the raceway of the measured lead screw and perpendicular to the contact angle direction line of the normal cross-sectional profile of the raceway of the measured lead screw, so that the spectral confocal sensor is within the working distance and the light spot is at the position of the normal cross-sectional profile of the raceway. A spectral confocal sensor clamping plate connected to a two-dimensional fine-tuning translation platform is used to fix the spectral confocal sensor.

3. The ball screw helical raceway waviness detection device based on a spectral confocal sensor according to claim 2, characterized in that, The turntable is connected to the two-dimensional coarse adjustment translation platform via a second connecting plate and an L-shaped plate.

4. The ball screw helical raceway waviness detection device based on a spectral confocal sensor according to claim 2, characterized in that, The two-dimensional fine-tuning translation platform is connected to the turntable via a second connecting plate.

5. The ball screw helical raceway waviness detection device based on a spectral confocal sensor according to claim 1, characterized in that, The dragging mechanism includes: A sliding support mounting plate for the towing mechanism; The mounting plate can slide horizontally radially along the lead screw being measured on the mounting plate of the drag mechanism. The one-dimensional translation platform fixed on the mounting plate can move parallel to the axis of the lead screw being measured, so that the drag head of the drag rod is aligned with the raceway of the lead screw being measured. A drag bar fixed on a one-dimensional translation platform is used to align the raceway of the lead screw being measured. The elastic mechanism is used to make the rod and the lead screw being measured make elastic contact.

6. The ball screw helical raceway waviness detection device based on a spectral confocal sensor according to claim 5, characterized in that, The elastic mechanism includes: a guide frame, a sleeve, a bolt, and a compression spring; The bolt passes through the guide groove of the guide frame and is mounted on the mounting plate; the sleeve is fitted onto the bolt and passes through the guide groove of the guide frame; the compression spring is fitted onto the sleeve and is located between the guide frame and the mounting plate.

7. The ball screw helical raceway waviness detection device based on a spectral confocal sensor according to claim 5, characterized in that, The drag rod is installed in the guide groove of the drag frame and can slide and be fixed along the guide groove.

8. The ball screw helical raceway waviness detection device based on a spectral confocal sensor according to claim 1, wherein the detachable connecting seat includes a mounting base, a connecting seat compression spring, a nut, and a guide rod; the nut is mounted on the mounting base, and the position of the guide rod is adjusted to control the disengagement and connection of the top end of the guide rod with the drive screw; the guide rod is a smooth rod that passes through the nut and the mounting base; the connecting seat compression spring is installed between the mounting base and the guide rod to press the top end of the guide rod into the raceway of the drive screw.

9. The ball screw helical raceway waviness detection device based on a spectral confocal sensor according to claim 1, wherein the distance acquisition unit is a linear grating ruler.

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