A clearance detection device and method for large-size angular contact ball bearings.

Abstract

This invention discloses a clearance detection device and method for large-size angular contact ball bearings, belonging to the field of bearing manufacturing and testing technology. To address the problem that existing technologies cannot detect the clearance of large-size angular contact ball bearings, the detection device includes an annular pad, two magnetic dial indicators, six support plate structures, and multiple positioning pins. The six support plate structures are equidistantly arranged circumferentially on the upper surface of the annular pad. The bearing to be tested is placed on the upper surface of the six support plate structures, and the bearing to be tested, the annular pad, and the six support plate structures are detachably connected by multiple positioning pins. The two magnetic dial indicators are mounted on the upper surface of the bearing to be tested and are magnetically fixed to the outer ring of the bearing. This invention is mainly used for detecting the clearance of large-size angular contact ball bearings.

Description

Technical Field

[0001] This invention belongs to the field of bearing manufacturing and testing technology, specifically relating to a clearance testing device and method for large-size angular contact ball bearings. Background Technology

[0002] The commonly used radial and axial clearance measuring instruments in the bearing industry are X095 and X196, respectively. However, due to their size limitations, they are only suitable for bearings with an outer diameter of less than 350 mm. A certain type of four-point angular contact ball bearing has an outer diameter of 1200 mm, far exceeding the testing range of existing instruments. Furthermore, the bearing's inner ring has a thin-walled structure, and the deformation caused by its own weight when placed vertically reaches 0.3 mm, making it impossible to use vertical measurement methods for radial clearance inspection. Therefore, it is essential to develop a clearance testing device and method for large-size angular contact ball bearings. Summary of the Invention

[0003] In order to solve the problem that the prior art cannot detect the clearance of large-size angular contact ball bearings, the present invention provides a clearance detection device and detection method for large-size angular contact ball bearings;

[0004] A clearance detection device for large-size angular contact ball bearings includes an annular pad, two magnetic dial indicators, six support plate structures, and multiple positioning pins. The six support plate structures are equidistantly arranged on the upper surface of the annular pad in the circumferential direction. The bearing to be tested is arranged on the upper surface of the six support plate structures, and the bearing to be tested, the annular pad, and the six support plate structures are detachably connected by multiple positioning pins. The two magnetic dial indicators are set on the upper surface of the bearing to be tested and are magnetically fixed to the outer ring of the bearing to be tested.

[0005] Furthermore, the upper surface of the annular pad is machined with multiple No. 1 positioning through holes at equal intervals along the circumference;

[0006] Furthermore, the support plate structure includes a support plate and two adjusting bolts. The support plate includes a mounting plate and an adjusting plate. The thickness of the mounting plate is greater than the thickness of the adjusting plate. The adjusting plate is disposed on one end of the mounting plate and is integrally formed with the mounting plate. The bottom surface of the mounting plate and the bottom surface of the adjusting plate are coplanar. The upper surface of the mounting plate is machined with two No. 2 positioning through holes, and each No. 2 positioning through hole is correspondingly matched with the No. 1 positioning through hole. The upper surface of the adjusting plate is machined with two threaded through holes. Each adjusting bolt is inserted into one threaded through hole and is threadedly connected to the threaded through hole. The screwing part of each adjusting bolt is disposed below the adjusting plate.

[0007] A method for detecting clearance in large-size angular contact ball bearings, the method comprising the following steps:

[0008] Step 1: Install the bearing to be tested onto the bearing clearance detection device;

[0009] Step 2: Measure the radial clearance of the bearing under test;

[0010] Step 3: Measure the axial clearance of the bearing under test;

[0011] Step 4: Remove the tested bearing from the bearing clearance detection device and repeat the above process to perform clearance detection on a batch of bearings to be tested;

[0012] Furthermore, the installation of the bearing to be tested on the bearing clearance detection device in step one is specifically achieved through the following steps:

[0013] Step 11: Multiple No. 3 locating through holes are machined equidistantly along the circumferential direction on the upper surface of the outer ring of the bearing to be tested. Each No. 3 locating through hole is matched with a No. 2 locating through hole and a No. 1 locating through hole.

[0014] Step 1 and 2: Place the bearing to be tested, which has multiple No. 3 positioning through holes, on the six support plate structure, and ensure that the outer ring of the bearing to be tested is in contact with the mounting plate in the support plate, and the inner ring of the bearing to be tested is located above the adjusting plate in the support plate.

[0015] Step 13: Pass each of the multiple locating pins through a No. 3 locating through hole, a No. 2 locating through hole, and a No. 1 locating through hole from top to bottom. Use the multiple locating pins to install the bearing outer ring, support plate, and annular pad of the bearing to be tested together.

[0016] Furthermore, the radial clearance measurement of the bearing under test in step two is specifically achieved through the following steps:

[0017] Step 21: Manually grip the bearing to be tested at the corresponding position of a support plate structure until there is no axial relative displacement between the inner and outer rings of the bearing. At this point, the inner ring of the bearing will rise. Simultaneously, adjust the adjusting bolt closest to the gripping point so that the top surface of the adjusting bolt contacts the bottom surface of the inner ring of the bearing.

[0018] Step 22: Repeat the process of Step 21, gripping the inner and outer rings of the bearing to be tested at the corresponding positions of the six support plate structures in sequence, and ensuring that the top of each adjusting bolt in the six support plate structures is in contact with the lower surface of the bearing inner ring.

[0019] Steps 2 and 3: After each adjusting bolt is adjusted to the correct position in step 2 and 2, use a height gauge to check the vertical distance between the upper end face of the bearing inner ring and the upper end face of the bearing outer ring at the corresponding positions of the six support plate structures. Ensure that the height of the bearing inner ring at the corresponding positions of the six support plate structures is consistent with the height of the bearing outer ring. When manually gripping the bearing inner ring and bearing outer ring again during the test, the vertical position of the upper end face of the inner ring should not change.

[0020] Step 24: Fix the two magnetic dial indicators in the testing device to the outer ring of the bearing, and set the measuring contacts of the two magnetic dial indicators at both ends of an inner diameter line in the outer ring of the bearing;

[0021] Step 25: Alternately grip the inner ring of the bearing at the measuring contact point to form a four-point contact with the steel ball and the outer ring of the bearing, and read the values ​​a and b of the two instruments. Then the radial clearance value of the bearing Gr = (a + b) / 2;

[0022] Furthermore, the axial clearance measurement of the bearing under test in step three is specifically achieved through the following steps:

[0023] Step 31: Manually adjust each adjusting bolt until the top of each adjusting bolt separates from the bottom of the bearing inner ring;

[0024] Step 32: Manually rotate the inner ring of the bearing until it comes to a stop relative to the outer ring.

[0025] Step 33: After the bearing inner ring stops, use a magnetic dial indicator to measure the vertical height H1 to H6 of the upper end face of the bearing inner ring relative to the upper end face of the bearing outer ring at the corresponding locations of the six support plate structures, and record the values.

[0026] Steps 3 and 4: Adjust each adjusting bolt in turn to move the inner ring of the bearing vertically upward to its limit position;

[0027] Step 35: After the inner ring of the bearing reaches its limit position, use a magnetic dial indicator to measure the vertical height H1′~H6′ of the upper end face of the inner ring of the bearing relative to the upper end face of the outer ring of the bearing at the corresponding positions of the six support plate structures, and record the values. Then the axial clearance value of the bearing is Ga=[(H1′-H1)+(H2′-H2)+(H3′-H3)+(H4′-H4)+(H5′-H5)+(H6′-H6)] / 6;

[0028] Furthermore, the removal of the bearing from the bearing clearance detection device in step four is specifically achieved through the following steps:

[0029] Step 41: Manually tighten each adjusting bolt to separate each adjusting bolt from its corresponding support plate;

[0030] Step 42: Remove the two magnetic dial indicators from the top of the outer ring of the bearing;

[0031] Step 43: Sequentially remove the positioning pins from one group of support plates that are positioned opposite each other in the six support plate structures;

[0032] Step 44: After all the locating pins have been removed, remove the rear bearing from the six support plate structures.

[0033] The beneficial effects of this application compared to the prior art are:

[0034] This invention provides a clearance detection device and method for large-size angular contact ball bearings. This process enables accurate detection of the radial and axial clearances of four-point angular contact ball bearings, with a detection repeatability of less than 0.006 mm. The horizontal placement of the detection method eliminates the influence of ring deformation on clearance detection. Furthermore, this detection method is low in cost, simple in structure, and easy to operate, making it suitable for application in the clearance detection process of similar large-size four-point angular contact ball bearings. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of the large-size angular contact ball bearing to be measured in this invention.

[0036] Figure 2 This is a schematic diagram of the radial clearance detection of the bearing under test according to the present invention (grasp tightly on the left);

[0037] Figure 3 This is a schematic diagram of the radial clearance detection of the bearing under test according to the present invention (grip tightly on the right);

[0038] Figure 4 This is a schematic diagram (lower limit) of the present invention for axial clearance detection of the bearing under test;

[0039] Figure 5 This is a schematic diagram (upper limit) of the present invention for detecting the axial clearance of the bearing under test;

[0040] Figure 6 This is a top view of the support plate in this invention;

[0041] Figure 7 This is a side view of the support plate in this invention;

[0042] Figure 8 This is a bottom view of the bearing under test mounted on the support plate structure in this invention;

[0043] In the diagram: 1. Steel ball, 2. Inner ring of bearing, 3. Outer ring of bearing, 31. No. 3 positioning through hole, 4. Support plate structure, 41. Support plate, 42. Adjusting bolt, 43. No. 2 positioning through hole, 44. Threaded through hole, 5. Annular pad, 51. No. 1 positioning through hole and 6. Magnetic dial indicator. Detailed Implementation

[0044] Specific implementation method one: Combining Figures 1 to 8 This embodiment provides a clearance detection device for large-size angular contact ball bearings. The detection device includes an annular pad 5, two magnetic dial indicators 6, six support plate structures 4, and multiple positioning pins. The six support plate structures 4 are equidistantly arranged on the upper surface of the annular pad 5 in the circumferential direction. The bearing to be tested is arranged on the upper surface of the six support plate structures 4, and the bearing to be tested, the annular pad 5, and the six support plate structures 4 are detachably connected by multiple positioning pins. The two magnetic dial indicators 6 are set on the upper surface of the bearing to be tested, and the two magnetic dial indicators 6 are magnetically attracted and fixed to the outer ring of the bearing to be tested.

[0045] Specific Implementation Method Two: Combining Figures 1 to 8 This embodiment differs from specific embodiment one in that the upper surface of the annular pad 5 is equidistantly machined with multiple No. 1 positioning through holes 51 along the circumferential direction. Other components and connection methods are the same as in specific embodiment one.

[0046] Specific implementation method three: Combining Figures 1 to 8 This embodiment differs from specific embodiment two in that the support plate structure 4 includes a support plate 41 and two adjusting bolts 42. The support plate 41 includes a mounting plate and an adjusting plate. The thickness of the mounting plate is greater than the thickness of the adjusting plate. The adjusting plate is disposed at one end of the mounting plate and is integrally formed with the mounting plate. The bottom surface of the mounting plate and the bottom surface of the adjusting plate are coplanar. The upper surface of the mounting plate is machined with two second-order positioning through holes 43, and each second-order positioning through hole 43 corresponds to and cooperates with the first-order positioning through hole 51. The upper surface of the adjusting plate is machined with two threaded through holes 44. Each adjusting bolt 42 is inserted into one threaded through hole 44 and is threadedly connected to the threaded through hole 44. The screwing part of each adjusting bolt 42 is located at the bottom of the adjusting plate. Other components and connection methods are the same as in specific embodiment two.

[0047] Specific implementation method four: Combination Figures 1 to 8 This embodiment describes a detection method implemented using a clearance detection device for large-size angular contact ball bearings. The method is achieved through the following steps:

[0048] Step 1: Install the bearing to be tested onto the bearing clearance detection device;

[0049] Step 2: Measure the radial clearance of the bearing under test;

[0050] Step 3: Measure the axial clearance of the bearing under test;

[0051] Step 4: Remove the tested bearing from the bearing clearance detection device and repeat the above process to perform clearance detection on a batch of bearings to be tested.

[0052] The working principle of this application is based on the clearance detection principle and the raceway structure of a four-point angular contact ball bearing. The bearing is placed in a horizontal state with the end face as the reference. The inner ring is a regular annular structure with its center of mass at the center of the circle. After free descent, it does not deflect relative to the outer ring and does not deform along its radial direction.

[0053] Specific Implementation Method Five: Combining Figures 1 to 8 This embodiment differs from Specific Embodiment Four in that, in step one, mounting the bearing to be tested on the bearing clearance detection device is specifically achieved through the following steps:

[0054] Step 11: Multiple No. 3 positioning through holes 31 are machined at equal intervals along the circumference on the upper surface of the outer ring 3 of the bearing to be tested. Each No. 3 positioning through hole 31 is matched with a No. 2 positioning through hole 43 and a No. 1 positioning through hole 51.

[0055] Step 1 and 2: Place the bearing to be tested, which has multiple No. 3 positioning through holes 31, on the six support plate structures 4, and ensure that the outer ring 3 of the bearing to be tested is in contact with the mounting plate in the support plate 41, and the inner ring 2 of the bearing to be tested is located above the adjustment plate in the support plate 41.

[0056] Step 13: Pass each of the multiple positioning pins through a No. 3 positioning through hole 31, a No. 2 positioning through hole 43, and a No. 1 positioning through hole 51 from top to bottom. Use the multiple positioning pins to install the bearing outer ring 3, support plate 41, and annular pad 5 of the bearing to be tested together.

[0057] The other components and operating methods are the same as those in Specific Implementation Method Four.

[0058] Specific Implementation Method Six: Combination Figures 1 to 8 This embodiment differs from specific embodiment five in that the radial clearance measurement of the bearing under test in step two is specifically achieved through the following steps:

[0059] Step 21: Manually grip the bearing to be tested at the corresponding position of a support plate structure 4 until there is no axial relative displacement between the inner ring 2 and the outer ring 3 of the bearing to be tested. At this time, the inner ring 2 of the bearing rises. At the same time, adjust the adjusting bolt 42 closest to the gripping position so that the top surface of the adjusting bolt 42 contacts the bottom surface of the inner ring 2 of the bearing.

[0060] Step 22: Repeat the process of Step 21, and hold the inner ring 2 and outer ring 3 of the bearing to be tested at the corresponding positions of the six support plate structures 4 in turn, and ensure that the top of each adjusting bolt 42 in the six support plate structures 4 is in contact with the lower surface of the inner ring 2 of the bearing.

[0061] Step 23: After each adjusting bolt 42 is adjusted into place in step 22, use a height gauge to check the vertical distance between the upper end face of the bearing inner ring 2 and the upper end face of the bearing outer ring 3 at the corresponding positions of the six support plate structures 4. Ensure that the height of the bearing inner ring 2 and the bearing outer ring 3 are consistent at the corresponding positions of the six support plate structures 4. The standard for checking is that the vertical position of the upper end face of the inner ring does not change when the bearing inner ring 2 and the bearing outer ring 3 are manually tightened again.

[0062] Step 24: Fix the two magnetic dial gauges 6 in the testing device onto the outer ring 3 of the bearing, and set the measuring contacts of the two magnetic dial gauges 6 at both ends of an inner diameter line in the outer ring 3 of the bearing.

[0063] Step 25: Alternately grip the inner ring 2 of the bearing at the measuring contact point to form a four-point contact with the steel ball 1 and the outer ring 3 of the bearing, and read the values ​​a and b of the two instruments. Then the radial clearance value of the bearing Gr = a + b / 2.

[0064] The other components and operating methods are the same as those in Specific Implementation Method 5.

[0065] Specific implementation method seven: Combining Figures 1 to 8 This embodiment differs from specific embodiment six in that the radial clearance measurement of the bearing under test in step two is specifically achieved through the following steps:

[0066] The axial clearance measurement of the bearing under test in step three is specifically achieved through the following steps:

[0067] Step 31: Manually adjust each adjusting bolt 42 so that the top of each adjusting bolt 42 separates from the bottom of the inner ring 2 of the bearing;

[0068] Step 32: Manually rotate the inner ring 2 of the bearing until it comes to a stop relative to the outer ring 3 of the bearing;

[0069] Step 33: After the bearing inner ring 2 stops, use a magnetic dial indicator 6 to measure the vertical height H1 to H6 of the upper end face of the bearing inner ring 2 relative to the upper end face of the bearing outer ring 3 at the corresponding positions of the six support plate structures 4, and record the values.

[0070] Steps 3 and 4: Adjust each adjusting bolt 42 in turn to make the inner ring 2 of the bearing move vertically upward and reach the limit position;

[0071] Step 35: After the inner ring 2 of the bearing reaches its limit position, use a magnetic dial indicator 6 to measure the vertical height H1′~H6′ of the upper end face of the inner ring 2 of the bearing relative to the upper end face of the outer ring 3 of the bearing at the corresponding positions of the six support plate structures 4, and record the values. Then the axial clearance value of the bearing is Ga=[H1′-H1+H2′-H2+H3′-H3+H4′-H4+H5′-H5+H6′-H6] / 6.

[0072] The other components and operating methods are the same as those in Specific Implementation Method Six.

[0073] Specific implementation method eight: Combination Figures 1 to 8 This embodiment differs from specific embodiment seven in that, in step four, removing the bearing from the bearing clearance detection device is specifically achieved through the following steps:

[0074] Step 41: Manually tighten each adjusting bolt 42 to separate each adjusting bolt 42 from the support plate 41 it is attached to;

[0075] Step 42: Remove the two magnetic dial indicators 6 from the top of the outer ring 3 of the bearing;

[0076] Step 43: Sequentially remove the positioning pins in a set of support plate structures 4 that are arranged opposite each other in the six support plate structures 4;

[0077] Step 44: After all the locating pins have been removed, remove the rear bearing from the six support plate structure 4.

[0078] The other components and operating methods are the same as those in Specific Implementation Method Seven.

[0079] The present invention has been disclosed above with preferred embodiments, but it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed structure and technical content to create equivalent embodiments without departing from the scope of the present invention. However, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for detecting the clearance of a large-size angular contact ball bearing, the method being implemented by means of a device for detecting the clearance of a large-size angular contact ball bearing, the detection device comprising an annular pad (5), two magnetic dial gauges (6), six support plate structures (4) arranged equidistantly in the circumferential direction on the upper surface of the annular pad (5), and a plurality of positioning pins, the bearing to be measured being arranged on the upper surfaces of the six support plate structures (4), and the bearing to be measured, the annular pad (5) and the six support plate structures (4) being detachably connected by means of the plurality of positioning pins, the two magnetic dial gauges (6) being arranged on the upper surface of the bearing to be measured, and the two magnetic dial gauges (6) being magnetically attracted to the outer ring of the bearing to be measured; a plurality of first positioning through holes (51) are equidistantly machined in the circumferential direction on the upper surface of the annular pad (5); the support plate structure (4) comprises a support plate (41) and two adjusting bolts (42), the support plate (41) comprises a mounting plate body and an adjusting plate body, the thickness of the mounting plate body being greater than the thickness of the adjusting plate body, the adjusting plate body being arranged on one end of the mounting plate body and being integrally formed with the mounting plate body, the bottom surface of the mounting plate body being coplanarly arranged with the bottom surface of the adjusting plate body, the upper surface of the mounting plate body being machined with two second positioning through holes (43), each second positioning through hole (43) being correspondingly arranged with a first positioning through hole (51), the upper surface of the adjusting plate body being machined with two threaded through holes (44), each adjusting bolt (42) being inserted into one threaded through hole (44) and being threadedly connected with the threaded through hole (44), and the screwing part of each adjusting bolt (42) being arranged below the adjusting plate body; characterized in that the method is implemented by the following steps: Step one: installing the bearing to be measured on the bearing clearance detection device; Step two: measuring the radial clearance of the bearing to be measured; the step two is implemented by the following steps: Step two one: manually holding the bearing to be measured at the corresponding position of one support plate structure (4) until there is no axial relative displacement between the inner ring (2) and the outer ring (3) of the bearing to be measured, at which time the inner ring (2) rises, and the adjusting bolt (42) closest to the holding position is adjusted so that the top surface of the adjusting bolt (42) is in contact with the bottom surface of the inner ring (2); Step two two: repeating the process of step two one to hold the inner ring (2) and the outer ring (3) of the bearing to be measured at the corresponding positions of the six support plate structures (4), and ensuring that the top of each adjusting bolt (42) in the six support plate structures (4) is in contact with the lower surface of the inner ring (2). Step two three: after each adjusting bolt (42) is adjusted in place in step two two, the vertical distance between the upper end surface of the bearing inner ring (2) and the upper end surface of the bearing outer ring (3) corresponding to the six support plate structures (4) is detected by using the height gauge, so as to ensure that the height of the bearing inner ring (2) corresponding to the six support plate structures (4) is consistent with the height of the bearing outer ring (3); when the detection is carried out, the standard is that the vertical position of the upper end surface of the bearing inner ring (2) does not change when the bearing inner ring (2) and the bearing outer ring (3) are manually held again; Step two four: the two magnetic dial gauges (6) in the detection device are fixed on the bearing outer ring (3), and the measurement contacts of the two magnetic dial gauges (6) are respectively arranged at the two ends of the inner diameter of the bearing outer ring (3); Step two five: the bearing inner ring (2) at the measurement contact is alternately held tightly to form four-point contact with the steel ball (1) and the bearing outer ring (3), and the values a and b of the two instruments are read, and then the bearing radial clearance value Gr=(a+b) / 2; Step three: axial clearance measurement is carried out on the bearing to be measured; Step four: the measured bearing is disassembled from the bearing clearance detection device, and the working process of steps one to three is repeated to realize clearance detection on a batch of bearings to be measured.

2. A method of detecting play for a large size angular contact ball bearing according to claim 1, characterized in that: In step one, the bearing to be measured is mounted on the bearing clearance detection device by the following steps: Step one one: a plurality of third positioning through holes (31) are processed on the upper surface of the bearing outer ring (3) in the bearing to be measured in a circumferential equidistant manner, and each third positioning through hole (31) is arranged in cooperation with a second positioning through hole (43) and a first positioning through hole (51); Step one two: the bearing to be measured with a plurality of third positioning through holes (31) is placed on the six support plate structures (4), and the bearing outer ring (3) of the bearing to be measured is ensured to be in contact with the mounting plate body in the support plate (41), and the bearing inner ring (2) of the bearing to be measured is located above the adjusting plate body in the support plate (41); Step one three: each positioning pin column in the plurality of positioning pin columns is sequentially inserted through a third positioning through hole (31), a second positioning through hole (43) and a first positioning through hole (51) from top to bottom, and the bearing outer ring (3) of the bearing to be measured, the support plate (41) and the annular pad (5) are mounted together through the plurality of positioning pin columns.

3. A method of detecting the play of a large-size angular contact ball bearing according to claim 2, characterized in that: In step three, the axial clearance of the bearing to be measured is measured by the following steps: Step three one: each adjusting bolt (42) is manually adjusted so that the top of each adjusting bolt (42) is separated from the bottom of the bearing inner ring (2); Step three two: the bearing inner ring (2) is manually rotated to be freely stopped relative to the bearing outer ring (3); Step three three: after the bearing inner ring (2) is stopped, the vertical heights H1-H6 of the upper end surface of the bearing inner ring (2) corresponding to the six support plate structures (4) relative to the upper end surface of the bearing outer ring (3) are measured by using the magnetic dial gauge (6), and the values are recorded; Step three four: each adjusting bolt (42) is adjusted in sequence, so that the bearing inner ring (2) moves vertically upward and reaches the limit position; Step three five: after the bearing inner ring (2) reaches the limit position upward, the vertical height H1'-H6' of the corresponding position of the six support plate structures (4) on the upper end surface of the bearing inner ring (2) relative to the upper end surface of the bearing outer ring (3) is measured by using the magnetic dial gauge (6), and the value is recorded, then the bearing axial clearance value Ga=[(H1'-H1)+(H2'-H2)+(H3'-H3)+(H4'-H4)+(H5'-H5)+(H6'-H6)] / 6.

4. A method of detecting the play of a large-size angular contact ball bearing according to claim 3, characterized in that: The step four is specifically realized by the following steps: Step four one: manually screw each adjusting bolt (42) to separate each adjusting bolt (42) from the support plate (41) where it is located; Step four two: remove the two magnetic dial gauges (6) from the top of the bearing outer ring (3); Step four three: sequentially remove the positioning pin columns in a set of the six support plate structures (4) which are oppositely arranged; Step four four: after all the positioning pin columns are removed, the measured bearing is removed from the six support plate structures (4).

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