Method for detecting the inner ring raceway position of self-aligning roller bearings based on coordinate measuring machine

Abstract

This invention provides a method for detecting the raceway position of the inner ring of a self-aligning roller bearing based on a coordinate measuring machine. First, a rectangular coordinate system is established on the inner ring of the self-aligning roller bearing to be tested. Then, a horizontal reference plane is set on one end face of the inner ring. When establishing the rectangular coordinate system on the self-aligning roller bearing using a coordinate measuring machine, one end face of the inner ring is used as the reference plane to coordinate the points on the inner ring. Multiple inner ring raceway circles are fitted based on the point coordinates of the inner ring. Then, a center plane is fitted based on the coordinates of the centers of the multiple inner ring raceway circles. By directly comparing the distance between the coordinates of the inner ring raceway circle centers along the bearing axis and the horizontal reference plane, as well as the distance between the center plane and the horizontal reference plane, the raceway position of the inner ring of the self-aligning roller bearing to be tested is determined to be qualified. This method avoids the need for at least one standard self-aligning roller bearing as a reference in existing technologies, thus improving testing efficiency.

Description

Technical Field

[0001] This invention relates to a method for measuring contours or curvature, and more particularly to a method for detecting the position of the inner ring raceway of a self-aligning roller bearing based on a coordinate measuring machine. Background Technology

[0002] Self-aligning roller bearings feature double-row rollers and two raceways on the inner ring that are angled relative to the bearing axis. This self-aligning property makes them less susceptible to interference from installation angles between the shaft and bearing housing. They can withstand large radial loads as well as certain bidirectional axial loads. The position of the inner ring raceway is a crucial factor determining the structural performance of a self-aligning roller bearing. If the deviation exceeds the allowable tolerance, it will cause misalignment in the contact area between the bearing rollers and the inner ring raceway, leading to premature bearing fatigue failure. Therefore, how to accurately detect the position of the inner ring raceway in a self-aligning roller bearing is a key concern for those skilled in the art.

[0003] Chinese utility model patent CN87201349U discloses a bearing inner ring raceway position and radius measuring instrument, including a rotatable measuring rod and a measuring instrument connected to the measuring rod. A standard self-aligning roller bearing inner ring is placed on the measuring instrument and the measuring rod contact is made to fit against its inner ring raceway. At this time, the measuring instrument is zeroed, and the standard self-aligning roller bearing inner ring is replaced with the self-aligning roller bearing inner ring to be tested. By reading the fluctuation range of the measuring instrument reading, the parameter difference between the bearing to be tested and the standard bearing is compared, thereby determining whether its dimensional accuracy is qualified.

[0004] The problem with this solution is that in many actual production measurements, it is necessary to directly measure the dimensions of the self-aligning roller bearing to be tested. However, the existing technology requires at least one standard self-aligning roller bearing to measure the geometric parameters of the inner ring raceway of the same model of self-aligning roller bearing. Moreover, the operation of the aforementioned measuring instrument is complicated and the detection efficiency is low. Once an operational error occurs, the measurement data will be inaccurate and remeasurement will be required, which is very inconvenient. Summary of the Invention

[0005] The purpose of this invention is to provide a method for detecting the position of the inner ring raceway of a self-aligning roller bearing based on a coordinate measuring machine, so as to solve the problems of slow speed and low efficiency in detecting the geometric parameters of the inner ring raceway of self-aligning roller bearings in the prior art.

[0006] To achieve the above objectives, this invention provides a method for detecting the position of the inner ring raceway of a self-aligning roller bearing based on a coordinate measuring machine, comprising the following steps:

[0007] S1: Fix the inner ring of the self-aligning roller bearing, take its end face as the XOY plane and its axis as the Z axis, establish a rectangular coordinate system, select any straight line passing through the Z axis on the XOY plane and identify it as the Y axis, and use the Y axis to determine the X axis;

[0008] S2: Based on the established rectangular coordinate system, select multiple points on one end face of the inner ring of the self-aligning roller bearing as horizontal reference plane measuring points, and fit the horizontal reference plane according to the horizontal reference plane measuring points;

[0009] S3: Select multiple measurement surfaces arranged circumferentially around the Z-axis. Select multiple points on the intersection line of the inner ring raceway of the self-aligning roller bearing and each measurement surface as inner ring raceway circle fitting measurement points. Obtain the coordinates of each inner ring raceway circle fitting measurement point according to the rectangular coordinate system.

[0010] S4: Fit the inner raceway circle on each measurement surface according to the coordinates of the fitting measurement points on each measurement surface, and determine the center coordinates of each inner raceway circle according to the rectangular coordinate system.

[0011] S5: Fit the center plane based on the measured coordinates of the centers of multiple inner raceway circles;

[0012] S6: Calculate the height difference between the center of each inner ring raceway circle in the Z-axis direction and the horizontal reference plane, and at the same time, calculate the height difference between the center plane and the horizontal reference plane. If both height differences are within the allowable tolerance range, the inner ring raceway position of the self-aligning roller bearing under test meets the requirements. If one of the height differences exceeds the allowable tolerance range, the inner ring raceway position of the self-aligning roller bearing under test does not meet the requirements.

[0013] Furthermore, in S1, a coordinate measuring machine is used to initially determine the rectangular coordinate system using the surface-circle-point method, and the upper end face of the self-aligning roller bearing is selected as the XOY plane of the rectangular coordinate system.

[0014] Furthermore, a coordinate measuring machine is used to manually establish a rough rectangular coordinate system, and then the automatic program function of the coordinate measuring machine is used to refine the rectangular coordinate system based on the rough rectangular coordinate system, thereby improving the detection accuracy.

[0015] Furthermore, in S2, the inner ring of the self-aligning roller bearing is horizontally positioned, and multiple points are selected on its upper end face as measuring points of the horizontal reference surface. The horizontal reference surface is then fitted based on the measuring points of the horizontal reference surface.

[0016] Furthermore, the multiple measurement surfaces selected in S3 that are arranged circumferentially around the Z-axis are all radial surfaces originating from the Z-axis.

[0017] Furthermore, the multiple measurement surfaces selected by S3 are uniformly arranged around the Z-axis at a certain angle.

[0018] Furthermore, four measurement surfaces were selected and arranged along the positive and negative directions of the X-axis and the Y-axis, respectively.

[0019] Furthermore, in S3, a coordinate measuring machine is used to uniformly select 16 inner ring raceway circle fitting measurement points along the intersection line of the inner ring raceway of the self-aligning roller bearing on the measurement surface.

[0020] Furthermore, in S2, a coordinate measuring machine is used to uniformly select 16 points around the axis on one end face of the inner ring of the self-aligning roller bearing as horizontal reference plane measuring points, and a horizontal reference plane is fitted based on the 16 horizontal reference plane measuring points.

[0021] Furthermore, the coordinate measuring machine in S3 uses a horizontally positioned contact, which is rotated about the Z-axis to select the inner raceway circle fitting measurement point.

[0022] Beneficial effects:

[0023] This invention innovatively provides a method for detecting the raceway position of the inner ring of a self-aligning roller bearing based on a coordinate measuring machine (CMM). The CMM is used to measure the raceway position of the inner ring of the self-aligning roller bearing. First, a rectangular coordinate system is established on the inner ring of the self-aligning roller bearing. Then, a horizontal reference plane is set on one end face of the self-aligning roller bearing to be measured. When establishing the rectangular coordinate system on the self-aligning roller bearing using the CMM, one end face of the inner ring of the self-aligning roller bearing is set as a plane of the coordinate system. The axis of the inner ring of the self-aligning roller bearing is selected as the coordinate axis perpendicular to the aforementioned plane in the rectangular coordinate system. The dimensions of the inner ring of the self-aligning roller bearing are then determined. The process involves parametric coordinateization. Multiple inner ring raceway circles are fitted based on the coordinates of points on the raceway of the self-aligning roller bearing. Then, a central plane is fitted based on the coordinates of the centers of these circles. Next, an end face of the inner ring is selected, and multiple points are chosen on this end face. A horizontal reference plane is fitted based on the coordinates of these points and used as a benchmark for comparing the distances between the center points. By comparing the distances between the coordinates of the inner ring raceway centers along the bearing's axis and the horizontal reference plane, as well as the distances between the central plane and the horizontal reference plane, the quality of the raceway position of the inner ring of the bearing under test is determined. A coordinate measuring machine (CMM) is used to inspect the geometric parameters of the raceway position of the inner ring of the self-aligning roller bearing. By coordinate-based measurement of the raceway, the geometric data of the bearing under test is converted into coordinates. This allows for rapid inspection of the inner ring's quality by measuring only the raceway points, avoiding the need for at least one standard self-aligning roller bearing as a reference in existing technologies, thus improving inspection efficiency. Attached Figure Description

[0024] Figure 1 This is a flowchart of the detection process for the inner ring raceway position detection method of a self-aligning roller bearing based on a coordinate measuring machine.

[0025] Figure 2 This is a schematic diagram of the cross-section of a selected point on the inner ring of a self-aligning roller bearing when roughly establishing a rectangular coordinate system.

[0026] Figure 3 This is a top view of the selected points on the inner ring of the self-aligning roller bearing when roughly establishing the rectangular coordinate system.

[0027] Figure 4 This is a top view of the selected points on the inner ring of the self-aligning roller bearing when establishing a precise rectangular coordinate system.

[0028] Figure 5 A top view of the points selected when establishing a horizontal reference plane on the inner ring of a self-aligning roller bearing;

[0029] Figure 6 A schematic diagram of the cross-section of the selected point when establishing a horizontal reference plane on the inner ring of a self-aligning roller bearing;

[0030] Figure 7 A schematic diagram of the cross-section where points are selected to fit the inner raceway circle;

[0031] Figure 8 This is a schematic diagram of the inner raceway circle.

[0032] In the figure: 1. Inner ring of self-aligning roller bearing; 2. Coarse selection reference surface measuring point; 3. Coarse selection circumferential surface measuring point; 4. Inner ring end face point; 5. Fine selection reference surface measuring point; 6. Fine selection circumferential surface measuring point; 7. Horizontal reference surface measuring point; 8. Inner ring raceway circle fitting measuring point; 9. Inner ring raceway circle; 10. Center of inner ring raceway circle. Detailed Implementation

[0033] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0034] The principle and concept of this invention are as follows: First, a coordinate measuring machine is used to establish a rectangular coordinate system on the inner ring of the self-aligning roller bearing to be tested. Then, a horizontal reference plane is set on one end face of the self-aligning roller bearing to be tested. When establishing the coordinate system, the axis of the inner ring of the self-aligning roller bearing is used as the Z-axis of the rectangular coordinate system, and the end face where the horizontal reference plane is located is used as the XOY plane. The probe of the coordinate measuring machine, set horizontally, uniformly selects multiple points from top to bottom along the intersection of the raceways, and fits the inner ring raceway circle according to the coordinates of the points. By rotating the probe, multiple sets of coordinate parameters of the inner ring raceway circle are obtained. The center plane is fitted based on the coordinates of the center of the inner raceway circle. The distance difference between the center of the inner raceway circle in the Z-axis direction and the horizontal reference plane, as well as the distance difference between the center plane and the horizontal reference plane, are recorded for multiple sets. The above distance differences are compared with the standard allowable tolerance of the inner raceway position of the same type of self-aligning roller bearing. If both distance differences are within the allowable tolerance range, the raceway position of the inner raceway of the self-aligning roller bearing under test is deemed qualified. Conversely, if any data is not within the tolerance range, the raceway position of the inner raceway of the self-aligning roller bearing under test is deemed unqualified.

[0035] Based on the above principles and concepts, this invention provides an embodiment of a method for detecting the position of the inner ring raceway of a self-aligning roller bearing based on a coordinate measuring machine, comprising the following steps:

[0036] S1: Fix the inner ring 1 of the self-aligning roller bearing, take one end face of the inner ring 1 of the self-aligning roller bearing as the XOY plane, and take the axis of the self-aligning roller bearing 1 as the Z axis to establish a rectangular coordinate system. Select any point on the XOY plane, draw a straight line perpendicular to the Z axis through the point, and define the axis of the line as the Y axis. The direction of the foot of the perpendicular toward the point is taken as the positive direction of the Y axis.

[0037] Select one end face of the self-aligning roller bearing 1 as the XOY plane. Using a coordinate measuring machine (CMM), establish a rectangular coordinate system using the surface-circle-point method. First, a rough rectangular coordinate system needs to be established. Manually operate the vertical probe of the CMM to evenly select three rough selection reference plane measurement points 2 on the selected end face. Use the end face element program of the CMM to output the rough selection XOY plane based on the rough selection reference plane measurement points 2. Manually operate the horizontal probe of the CMM to select three rough selection circumferential surface measurement points 3 on the same cross section of the inner ring circumference of the self-aligning roller bearing 1. Use the diameter circle program of the CMM to output the rough selection XOY plane based on the three rough selection circumferential surface measurement points 3. A circular ring is selected. A straight line perpendicular to the XOY plane is drawn through the center of the coarsely selected circular ring. This straight line is considered to be the axis of the inner ring 1 of the self-aligning roller bearing and is used as the Z-axis of the rectangular coordinate system. Then, any inner ring end face point 4 is selected on the coarsely selected XOY plane. A straight line perpendicular to the Z-axis is drawn through the inner ring end face point 4. The direction from the foot of the line to the inner ring end face point 4 is the positive direction of the Y-axis. A straight line perpendicular to the Y-axis and extending to both sides of the Y-axis is drawn and defined as the X-axis. In another embodiment, four coarsely selected circumferential surface measuring points 3 and four coarsely selected reference surface measuring points 2 can also be selected. The number of measuring points is greater than three but does not need to be too many. Selecting different numbers of measuring points falls within the protection scope of this invention.

[0038] When establishing a precise rectangular coordinate system, the coarse rectangular coordinate system is used as a foundation. The automatic mode of the coordinate measuring machine is selected to establish the precise rectangular coordinate system. Eight carefully selected reference surface measuring points 5 are uniformly selected around the Z-axis on the upper surface to generate a plane. Then, eight carefully selected circular surface measuring points 6 are selected at the same height on the inner ring circumferential surface of the inner ring 1 of the self-aligning roller bearing to generate a circle. Then, a point is arbitrarily selected in the positive Y-axis direction determined in the coarse rectangular coordinate system. Using this point as a reference, the precise rectangular coordinate system is automatically established according to the surface-circle-point method. In another embodiment, more carefully selected reference surface measuring points 5 and more carefully selected circular surface measuring points 6 can be selected to establish a more accurate rectangular coordinate system. The selection of different numbers of measuring points falls within the protection scope of this invention.

[0039] exist Figure 1-4 In the provided embodiment, the inner ring 1 of the self-aligning roller bearing is placed horizontally on the testing platform, and an XOY plane for establishing a coordinate system is set on the upper end face of the inner ring 1 of the self-aligning roller bearing. In another embodiment, the inner ring of the self-aligning roller bearing to be tested can also be placed vertically and fixed, with its axis set in the horizontal direction. The end face of one side of the inner ring of the self-aligning roller bearing to be tested is used as the XOY plane, and a rectangular coordinate system is established with the axis as the Z-axis and tested.

[0040] The coordinate measuring machine and coordinate measuring program used in the above embodiments are all prior art. The coordinate measuring machine of the present invention can use the coordinate measuring instrument and the measurement program PCDMIS provided in the method for measuring the diameter and angle of the inner raceway of a cone provided by Chinese invention patent with publication number CN117091552A.

[0041] S2: Based on the established rectangular coordinate system, select multiple points on one end face of the inner ring 1 of the self-aligning roller bearing as horizontal reference surface measurement points 7, and fit the horizontal reference surface according to the horizontal reference surface measurement points 7.

[0042] like Figure 5-6 In the provided embodiment, 16 horizontal reference surface measuring points 7 are uniformly selected circumferentially on the upper end face of the horizontally placed self-aligning roller bearing inner ring 1 using a coordinate measuring machine. Then, the horizontal reference surface is fitted using the fitting program of the coordinate measuring machine based on the coordinates of the horizontal reference surface measuring points 7. At this time, the coordinates of the horizontal reference surface in the Z-axis direction may be 0 or not. In another embodiment, a horizontal reference surface can also be set on the lower end face of the self-aligning roller bearing inner ring 1. The geometric parameters of the raceway near the lower end face are detected by a coordinate measuring machine and compared with the Z-axis coordinates of the horizontal reference surface set on the lower end face to determine whether the position of the raceway to be tested is qualified.

[0043] S3: Select multiple measurement surfaces arranged circumferentially around the Z-axis. Select multiple points along the intersection line of the raceway of the inner ring 1 of the self-aligning roller bearing and each measurement surface as inner ring raceway circle fitting measurement points 8. Obtain the coordinates of each inner ring raceway circle fitting measurement point 8 according to the rectangular coordinate system.

[0044] like Figure 7 In the provided embodiment, four radial surfaces originating from the Z-axis are selected as measurement surfaces in this step, evenly arranged around the Z-axis at 90° intervals. The directions of the four measurement surfaces are respectively towards the positive and negative directions of the X-axis and the positive and negative directions of the Y-axis. In another embodiment, more sets of radial surfaces evenly arranged around the Z-axis can be selected, such as eight evenly arranged measurement surfaces at 45° intervals around the Z-axis, to obtain more accurate parameters of the inner raceway circle 9.

[0045] The coordinate measuring machine used in this invention includes a horizontally oriented probe. By rotating the orientation angle of the probe around the Z-axis, the coordinate data of multiple inner ring raceway circle fitting measurement points 8 on the intersection line of the four measuring surfaces and the raceway can be read. In another embodiment, a coordinate measuring machine with an annular probe holder can also be used. The annular probe holder is provided with multiple probes facing the center of the annular probe holder. The inner ring 1 of the self-aligning roller bearing is horizontally fixed in the probe holder. The probe is brought into contact with the raceway. By simply selecting probes in different directions and moving them along the intersection line, the coordinate data of multiple inner ring raceway circle fitting measurement points 8 on the raceway intersection line at the selected probe can be obtained.

[0046] S4: Fit the inner raceway circle 9 on each measurement surface according to the coordinates of the fitting measurement point 8 on each measurement surface, and determine the coordinates of the center 10 of each inner raceway circle according to the rectangular coordinate system.

[0047] like Figure 8 The provided embodiment uses the automatic circle programming function in the coordinate measurement program to output the inner raceway circle 9 based on the fitting measurement points 8 of the 16 inner raceway circles on each measurement surface.

[0048] S5: Fit the center plane based on the coordinates of the center 10 of the multiple inner raceway circles measured in S4.

[0049] Using the plane construction function in the coordinate measurement program, construct the center plane based on the coordinates of the center 10 of the four inner raceway circles.

[0050] S6: Record the height difference between the coordinates of the center 10 of the four inner ring raceway circles in the Z-axis direction and the horizontal reference plane, denoted as t1, t2, t3, and t4. At the same time, record the height difference between the center plane and the horizontal reference plane, denoted as t. If the above height differences are all within the allowable tolerance range of the inner ring raceway position of the same type of self-aligning roller bearing, the inner ring raceway position of the self-aligning roller bearing to be tested is deemed qualified. If any of the above five data exceeds the allowable tolerance range, the inner ring raceway position of the self-aligning roller bearing to be tested is deemed unqualified.

[0051] The distance evaluation function of the coordinate measuring machine software can be used to automatically determine the height difference between the center 10 of the inner raceway circle and the originally set horizontal reference plane. Similarly, the height difference between the center plane and the horizontal reference plane can be determined.

[0052] This invention uses a coordinate measuring machine to measure the inner ring of a self-aligning roller bearing. By establishing a rectangular coordinate system on the inner ring of the bearing under test, the geometric parameters of the inner ring are coordinateized, allowing for the rapid acquisition of the position coordinates of the center 10 of the inner ring raceway. These coordinates are then compared with the distance to a pre-set horizontal reference plane for evaluation. The measurement method is reliable and effective. The detection method provided by this invention has extremely high versatility and is suitable for rapid detection during batch processing of the inner ring raceway of self-aligning roller bearings, improving inspection efficiency and effectively solving the problems of difficult and inefficient detection of the inner ring raceway position in existing self-aligning roller bearings.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. A method for detecting the raceway position of the inner ring of a self-aligning roller bearing based on a coordinate measuring machine, characterized in that, include: S1: Fix the inner ring of the self-aligning roller bearing, take its end face as the XOY plane and its axis as the Z axis, establish a rectangular coordinate system, select any straight line passing through the Z axis on the XOY plane and identify it as the Y axis, and use the Y axis to determine the X axis; S2: Based on the established rectangular coordinate system, select multiple points on one end face of the inner ring of the self-aligning roller bearing as horizontal reference plane measuring points, and fit the horizontal reference plane according to the horizontal reference plane measuring points; S3: Select multiple measurement surfaces arranged circumferentially around the Z-axis. Select multiple points on the intersection line of the inner ring raceway of the self-aligning roller bearing and each measurement surface as inner ring raceway circle fitting measurement points. Obtain the coordinates of each inner ring raceway circle fitting measurement point according to the rectangular coordinate system. S4: Fit the inner raceway circle on each measurement surface according to the coordinates of the fitting measurement points on each measurement surface, and determine the center coordinates of each inner raceway circle according to the rectangular coordinate system. S5: Fit the center plane based on the measured coordinates of the centers of multiple inner raceway circles; S6: Calculate the height difference between the center of each inner ring raceway circle in the Z-axis direction and the horizontal reference plane, and at the same time, calculate the height difference between the center plane and the horizontal reference plane. If both height differences are within the allowable tolerance range, the inner ring raceway position of the self-aligning roller bearing under test meets the requirements. If one of the height differences exceeds the allowable tolerance range, the inner ring raceway position of the self-aligning roller bearing under test does not meet the requirements.

2. The method for detecting the inner ring raceway position of a self-aligning roller bearing based on a coordinate measuring machine according to claim 1, characterized in that, In S1, a coordinate measuring machine is used to initially determine the rectangular coordinate system using the surface-circle-point method, and the upper end face of the self-aligning roller bearing is selected as the XOY plane of the rectangular coordinate system.

3. The method for detecting the inner ring raceway position of a self-aligning roller bearing based on a coordinate measuring machine according to claim 2, characterized in that, Using a coordinate measuring machine, a rough rectangular coordinate system is manually established, and then, based on the rough rectangular coordinate system, the automatic program function of the coordinate measuring machine is used to refine the rectangular coordinate system, thereby improving the detection accuracy.

4. The method for detecting the inner ring raceway position of a self-aligning roller bearing based on a coordinate measuring machine according to claim 1, characterized in that, In S2, the inner ring of the self-aligning roller bearing is horizontally positioned, and multiple points are selected on its upper surface as measuring points of the horizontal reference surface. The horizontal reference surface is then fitted based on the measuring points of the horizontal reference surface.

5. The method for detecting the inner ring raceway position of a self-aligning roller bearing based on a coordinate measuring machine according to any one of claims 1-4, characterized in that, The multiple measurement surfaces selected in S3 that are arranged circumferentially around the Z-axis are all radial surfaces originating from the Z-axis.

6. The method for detecting the inner ring raceway position of a self-aligning roller bearing based on a coordinate measuring machine according to claim 5, characterized in that, The multiple measurement surfaces selected by S3 are uniformly arranged around the Z-axis at a certain angle.

7. The method for detecting the inner ring raceway position of a self-aligning roller bearing based on a coordinate measuring machine according to claim 6, characterized in that, Four measurement surfaces were selected and arranged along the positive and negative directions of the X-axis and the Y-axis, respectively.

8. The method for detecting the position of the inner ring raceway of a self-aligning roller bearing based on a coordinate measuring machine according to any one of claims 1-4, characterized in that, in S3, a coordinate measuring machine is used to uniformly select 16 inner ring raceway circle fitting measurement points along the intersection line of the inner ring raceway of the self-aligning roller bearing on the measurement surface.

9. The method for detecting the raceway position of the inner ring of a self-aligning roller bearing based on a coordinate measuring machine according to any one of claims 1-4, characterized in that, in S2, a coordinate measuring machine is used to uniformly select 16 points around the axis on one end face of the inner ring of the self-aligning roller bearing as horizontal reference plane measuring points, and a horizontal reference plane is fitted according to the 16 horizontal reference plane measuring points.

10. The method for detecting the inner ring raceway position of a self-aligning roller bearing based on a coordinate measuring machine according to any one of claims 1-4, characterized in that, The S3 coordinate measuring machine uses a horizontally positioned contact point. The inner raceway circle fitting measurement point is selected by rotating the contact point about the Z-axis.

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