Device and method for measuring axial guide angle of bearing inner ring
By designing a fast measuring device for the axial guide angle of the bearing inner ring, the combination of a dial gauge and a measuring head solves the problem of low measurement efficiency in the prior art, and efficient batch measurement of the axial guide angle of the bearing inner ring is achieved, which significantly improves product quality and installation pass rate.
Patent Information
- Application Number
- CN202411764652.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-04
- Publication Date
- 2025-03-28
AI Technical Summary
The prior art has low measurement efficiency in batch measurement of axial guide angle of the bearing inner ring, which cannot meet the needs of large-scale measurement, and the traditional method has a long measurement time, about 3 to 5 minutes.
An axial guide angle measuring device for the inner ring of the bearing including a dial meter, a meter seat, a measuring head and a paddle is designed. The axial guide angle of the bearing inner ring is within the allowable tolerance range by the needle reading of the dial meter, and the measurement time is greatly shortened to about 0.2 minutes.
It improves the operability and measurement efficiency of batch measurement of axial guide angle of the bearing inner ring, and effectively improves the product quality and installation pass rate of the bearing.
Smart Images
Figure CN119714025A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a measuring tool and a measuring method for bearing production, and in particular to an axial guide angle measuring device and a measuring method for a bearing inner ring. Background Art
[0002] The axial guide angle of the inner ring of the bearing is generally 15°, and the allowable tolerance range is 15°±2°. The axial guide angle plays a relatively important role in the installation of the bearing. Its function is to guide the inner ring of the bearing to enter the installation position smoothly, avoid the misalignment and tilt of the bearing during the installation process, and can also reduce the stress concentration during the bearing assembly and extend the service life of the bearing.
[0003] If the axial guide angle of the inner ring of the bearing exceeds the allowable tolerance range, it may cause problems such as improper bearing assembly, tilting and stress concentration, resulting in poor bearing installation. Therefore, it is particularly important to measure the axial guide angle of the inner ring of the bearing before leaving the factory. For the axial guide angle of the inner ring of the bearing, most existing bearing manufacturers use the method of extracting small samples for measurement and use a profiler to measure the axial guide angle. Although the measurement accuracy is high, the measurement time is long. The measurement time required for a single bearing inner ring is about 3 to 5 minutes. The measurement efficiency is low and cannot meet the needs of large-scale measurement. Summary of the invention
[0004] The technical problem to be solved by the present invention is to provide a convenient and quick-to-use axial guide angle measuring device and method for the inner ring of a bearing, which can greatly improve the operability and measurement efficiency of batch measurement of the axial guide angle of the inner ring of the bearing. It only takes about 0.2 minutes to measure the axial guide angle of the inner ring of a single bearing. Compared with traditional methods, the measurement efficiency is greatly improved, which can effectively improve the product quality of the bearing and the qualified rate of the installation of the bearing.
[0005] The technical solution adopted by the present invention to solve the above technical problems is: an axial guide angle measuring device for the inner ring of a bearing, comprising a micrometer, a base, a measuring head and a paddle, wherein the micrometer is upright mounted on the base, the paddle is connected to the measuring rod of the micrometer, the paddle is used to drive the measuring rod to move up and down, the measuring head is fixed to the bottom end of the measuring rod, and two arched sliding blocks are elastically connected to the bottom of the measuring head, each of the sliding blocks can slide laterally, the outer diameter of each sliding block is adapted to the inner diameter of the inner ring of the bearing, and the radial surface of each sliding block is The surface is a measuring reference surface, and the measuring reference surface is inclined from top to bottom toward the radial inner side of the sliding block, and the angle between the measuring reference surface and the vertical direction is 15°±10′. A limit block for positioning the inner ring of the bearing is arranged directly below the measuring head. When measuring the axial guide angle of the inner ring of the bearing, the inner ring of the bearing is placed on the limit block, and the paddle is operated to move the measuring rod down until the measuring reference surfaces on the two sliding blocks are in full contact with the chamfered surface of the inner ring of the bearing. At this time, it is judged whether the axial guide angle of the inner ring of the bearing is within the allowable tolerance range according to the reading of the needle of the micrometer.
[0006] The axial guide angle measuring device of the bearing inner ring of the present invention is convenient and quick to use, and is convenient for operators to measure and use at any time, so as to realize batch measurement of the axial guide angle of the bearing inner ring, thereby efficiently screening out qualified bearing inner rings whose axial guide angle accuracy is consistent with the allowable tolerance range, and eliminating unqualified products. The measuring device can greatly improve the operability and measurement efficiency of batch measurement of the axial guide angle of the bearing inner ring, and effectively improve the product quality of the bearing and the qualified installation rate of the bearing. Compared with the long measurement time of 3 to 5 minutes required for the traditional profilometer to measure the axial guide angle of a single bearing inner ring, the device of the present invention only takes about 0.2 minutes to measure the axial guide angle of a single bearing inner ring, which greatly improves the measurement efficiency compared with the traditional method.
[0007] Preferably, two slideways are horizontally arranged in the measuring head, the lower side of each slideway is connected to a connecting groove, the upper part of each sliding block is vertically connected to a ball stud, each ball stud is inserted into a connecting groove, the ball head of each ball stud can be slidably arranged in one of the slideways, and a spring is installed in each of the slideways, the outer end of each spring is connected to a ball head, and the inner end of each spring is connected to the measuring head. The sliding connection between the sliding block and the measuring head is realized by the ball stud and the spring and other structures, and the structure is simple and reliable. During the batch measurement process, when the axial guide angle of the inner ring of the bearing to be measured changes, the sliding block can adaptively adjust its lateral sliding displacement under the elastic force of the spring to meet the measurement needs of different bearing inner rings with deviations in the axial guide angle. After the measurement of the inner ring of the previous bearing is completed, the measuring rod is lifted, and the sliding block can automatically move to the initial position before the measurement towards the radial outer side under the elastic force of the spring to prepare for the measurement of the next inner ring of the bearing.
[0008] As a further preferred embodiment, a limiting boss is integrally provided at the center of the bottom of the measuring head, and the limiting boss is located radially inward of the two sliding blocks. The limiting boss is used to limit the displacement of the two sliding blocks when they move toward each other, so as to prevent damage to the parts due to excessive displacement of the two sliding blocks when moving toward each other in an accidental situation.
[0009] As a further preferred embodiment, the position-limiting boss is hemispherical, and the radial inner surface of each sliding block is provided with an inclined surface adapted to the position-limiting boss. When each sliding block contacts and slides with the position-limiting boss, the inclined surface serves as the contact surface between the sliding block and the position-limiting boss, and plays a certain guiding and position-limiting role in the sliding of the sliding block, so that the movement of the sliding block can be more stable.
[0010] As a further preference, a cover plate is provided on the outer side of each slideway, and the cover plate is fixed to the outer side wall of the measuring head. Each slideway is filled with grease to reduce the sliding resistance of the sliding block. At the same time, the cover plate can prevent the ball head from falling out of the slideway, thereby ensuring the normal use of the measuring device.
[0011] Preferably, the bottom of the table seat is integrally provided with a bottom plate, the limit block is fixed on the bottom plate by interference fit, the upper part of the limit block is integrally provided with a positioning boss, the outer diameter of the positioning boss is adapted to the inner diameter of the inner ring of the bearing, and the center line of the positioning boss is on the same vertical line as the center line of the measuring head. The function of the positioning boss is to realize the rapid positioning of the inner ring of the bearing and further improve the measurement efficiency.
[0012] As a further preference, a handle is integrally provided on the side of the table base to facilitate the transportation and placement of the device.
[0013] Preferably, a support rod is fixed to one side of the dial gauge case, the middle portion of the paddle is hinged to the support rod, and the front end of the paddle is connected to the measuring rod of the dial gauge.
[0014] The measuring method of the axial guide angle measuring device of the bearing inner ring comprises the following steps:
[0015] (1) Produce a standard bearing inner ring with an axial guide angle of 15°±10′, and produce a defective bearing inner ring part 1 with an axial guide angle of 13°±10′ and a defective bearing inner ring part 2 with an axial guide angle of 17°±10′;
[0016] (2) Press the paddle downward, lift the measuring rod, place the standard part on the limit block, and then pull the paddle upward to allow the measuring rod to drive the measuring head downward. When the measuring reference surfaces on the two sliding blocks are in full contact with the chamfered surfaces of the standard part, the measuring head is limited and stops moving downward. At this time, return the needle of the micrometer to zero, and the standard value of the axial guide angle is set.
[0017] (3) Press the paddle downward, lift the measuring rod, remove the standard part, place the defective part 1 on the limit block, and then pull the paddle upward to make the measuring rod drive the measuring head to move downward. When the measuring reference surfaces on the two sliding blocks are in full contact with the chamfered surface of the defective part 1, the measuring head is limited and stops moving downward. The position of the needle at this time is marked as position 1 on the dial of the micrometer.
[0018] (4) Press the paddle downward, lift the measuring rod, remove the defective part 1, place the defective part 2 on the limit block, and then pull the paddle upward to allow the measuring rod to drive the measuring head downward. When the measuring reference surfaces on the two sliding blocks are in full contact with the chamfered surface of the defective part 2, the measuring head is limited and stops moving downward. The position of the needle at this time is marked as position 2 on the dial of the micrometer. Press the paddle downward again, lift the measuring rod, and remove the defective part 2. The reading between position 1 and position 2 on the dial of the micrometer is the allowable tolerance range.
[0019] (5) Place the inner ring of the bearing whose axial guide angle needs to be measured on the limit block, then pull up the paddle to allow the measuring rod to drive the measuring head downward. When the measuring reference surfaces on the two sliding blocks are in full contact with the chamfered surface of the inner ring of the bearing, the measuring head is limited and stops moving downward. Based on the reading of the needle of the micrometer at this time, determine whether the axial guide angle of the inner ring of the bearing is within the allowable tolerance range.
[0020] Compared with the prior art, the present invention has the following advantages: the axial guide angle measuring device and method of the bearing inner ring of the present invention are convenient and quick to use, and are convenient for operators to measure and use at any time, so as to realize batch measurement of the axial guide angle of the bearing inner ring. The measuring device and the measuring method of the present invention can greatly improve the operability and measurement efficiency of batch measurement of the axial guide angle of the bearing inner ring, and effectively improve the product quality of the bearing and the qualified installation rate of the bearing. Compared with the long measurement time of 3 to 5 minutes required by the traditional profiler to measure the axial guide angle of the inner ring of a single bearing, the device of the present invention only takes about 0.2 minutes to measure the axial guide angle of the inner ring of a single bearing, which greatly improves the measurement efficiency compared with the traditional method. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 A front view of the measuring device in the embodiment when measuring a standard part;
[0022] Figure 2 A front view of the measuring device in the embodiment when the axial guide angle of the bearing inner ring to be measured is greater than 15°±10′;
[0023] Figure 3 for Figure 2 The enlarged view of the local section at A in the middle;
[0024] Figure 4 After removing the ball stud Figure 3 Middle B view;
[0025] Figure 5 A front view of the measuring device in the embodiment when the axial guide angle of the bearing inner ring to be measured is less than 15°±10′;
[0026] Figure 6 for Figure 5 Enlarged view of point C in the middle;
[0027] The specific reference numerals in the figure are as follows:
[0028] 1-micrometer, 11-measuring rod, 12-needle, 2-base, 21-handle, 22-base plate, 3-measuring head, 31-slide, 32-connecting groove, 33-spring, 34-cover plate, 35-limiting boss, 4-paddle, 5-support rod, 6-sliding block, 61-measuring reference surface, 62-ball stud, 63-ball head, 64-inclined surface, 7-limiting block, 71-locating boss, 81-standard parts, 82-bearing inner ring with axial guide angle greater than 15°, 83-bearing inner ring with axial guide angle less than 15°. DETAILED DESCRIPTION
[0029] The present invention is further described in detail below in conjunction with the embodiments of the drawings. All components or structures not limited in the present invention adopt conventional technical means in the mechanical field.
[0030] Embodiment 1: A device for measuring the axial guide angle of a bearing inner ring, such as Figure 1 to Figure 5 As shown, the dial gauge 1 includes a dial base 2, a measuring head 3 and a paddle 4. The dial gauge 1 is upright mounted on the dial base 2. A support rod 5 is fixed to one side of the dial gauge 1 case. The middle of the paddle 4 is hinged to the support rod 5. The front end of the paddle 4 is connected to the measuring rod 11 of the dial gauge 1. The paddle 4 is used to drive the measuring rod 11 to move up and down. The measuring head 3 is fixed to the bottom end of the measuring rod 11 through a threaded connection. Two arched sliding blocks 6 are elastically connected to the bottom of the measuring head 3. Each sliding block 6 can slide laterally. The outer diameter of each sliding block 6 is adapted to the inner diameter of the inner ring of the bearing. The radial surface of each sliding block 6 The surface is the measuring reference surface 61, which is inclined from top to bottom toward the radial inner side of the sliding block 6, and the angle between the measuring reference surface 61 and the vertical direction is 15°±10′. A limit block 7 for positioning the inner ring of the bearing is provided directly below the measuring head 3. When measuring the axial guide angle of the inner ring of the bearing, the inner ring of the bearing is placed on the limit block 7, and the paddle 4 is operated to move the measuring rod 11 downward until the measuring reference surface 61 on the two sliding blocks 6 is in full contact with the chamfered surface of the inner ring of the bearing. At this time, the axial guide angle of the inner ring of the bearing is judged according to the reading of the needle 12 of the micrometer 1.
[0031] In Example 1, two slideways 31 are horizontally arranged in the measuring head 3, and the lower side of each slideway 31 is communicated with a connecting groove 32, and a ball stud 62 is vertically connected to the upper part of each sliding block 6, and each ball stud 62 is penetrated in a connecting groove 32, and the ball head 63 of each ball stud 62 is slidably arranged in a slideway 31, and a spring 33 is installed in each slideway 31, and the outer end of each spring 33 is connected with a ball head 63, and the inner end of each spring 33 is connected with the measuring head 3; a cover plate 34 is arranged on the outer side of each slideway 31, and the cover plate 34 is fixed to the outer wall of the measuring head 3 by bolts, and each slideway 31 is filled with grease; a hemispherical limiting boss 35 is integrally arranged at the center of the bottom of the measuring head 3, and the limiting boss 35 is located on the radial inner side of the two sliding blocks 6, and the radial inner surface of each sliding block 6 is provided with an inclined surface 64 adapted to the limiting boss 35.
[0032] In Example 1, a handle 21 is integrally provided on the side of the dial base 2, a base plate 22 is integrally provided on the bottom of the dial base 2, a limit block 7 is fixed on the base plate 22 by interference fit, a positioning boss 71 is integrally provided on the upper part of the limit block 7, the outer diameter of the positioning boss 71 is adapted to the inner diameter of the inner ring of the bearing, and the center line of the positioning boss 71 is on the same vertical line as the center line of the measuring head 3.
[0033] Embodiment 2: A method for measuring the axial guide angle of the bearing inner ring of the embodiment 1 comprises the following steps:
[0034] (1) A standard bearing inner ring part 81 with an axial guide angle of 15°±10′ is manufactured, and a defective bearing inner ring part 1 with an axial guide angle of 13°±10′ and a defective bearing inner ring part 2 with an axial guide angle of 17°±10′ are manufactured. The axial guide angles of the standard part 81, the defective part 1 and the defective part 2 are measured using a profilometer. The standard part 81, the defective part 1 and the defective part 2 can be used for a long time and only need to be calibrated regularly;
[0035] (2) Press down the paddle 4, lift the measuring rod 11, place the standard part 81 on the stop block 7, and then pull up the paddle 4, so that the measuring rod 11 drives the measuring head 3 to move downward. When the measuring reference surfaces 61 on the two sliding blocks 6 are in full contact with the chamfered surface of the standard part 81, the measuring head 3 is limited and stops moving downward. At this time, the needle 12 of the micrometer 1 is reset to zero. Figure 1 As shown, the setting of the standard value of the axial guide angle is completed;
[0036] (3) Press down the paddle 4, lift the measuring rod 11, remove the standard part 81, place the defective part 1 on the limit block 7, and then pull up the paddle 4, so that the measuring rod 11 drives the measuring head 3 to move downward. When the measuring reference surfaces 61 on the two sliding blocks 6 are in full contact with the chamfered surface of the defective part 1, the measuring head 3 is limited and stops moving downward. The position of the needle 12 at this time is marked as position 1 on the dial of the micrometer 1;
[0037] (4) Press down the paddle 4, lift the measuring rod 11, remove the defective part 1, place the defective part 2 on the limit block 7, and then pull up the paddle 4 so that the measuring rod 11 drives the measuring head 3 to move downward. When the measuring reference surface 61 on the two sliding blocks 6 is in full contact with the chamfered surface of the defective part 2, the measuring head 3 is limited and stops moving downward. The position of the needle 12 at this time is marked as position 2 on the dial of the micrometer 1. The position of the needle 12 at this time is marked on the dial of the micrometer 1, and then press down the paddle 4, lift the measuring rod 11, and remove the defective part 2. The reading between position 1 and position 2 on the dial of the micrometer 1 is the allowable tolerance range.
[0038] (5) Place the bearing inner ring whose axial guide angle needs to be measured on the limit block 7, then pull up the paddle 4, so that the measuring rod 11 drives the measuring head 3 to move downward. When the measuring reference surface 61 on the two sliding blocks 6 is in full contact with the chamfered surface of the bearing inner ring, the measuring head 3 is limited and stops moving downward. According to the reading of the needle 12 of the micrometer 1 at this time, it is judged whether the axial guide angle of the bearing inner ring is within the allowable tolerance range. Specifically, when the axial guide angle of the bearing inner ring 82 to be measured is greater than 15°±10′, due to the two sliding blocks 6, the measuring reference surface 61 on the two sliding blocks 6 is in full contact with the chamfered surface of the bearing inner ring. The angle between the measuring reference surface 61 and the vertical direction is smaller than the axial guide angle of the bearing inner ring 82 to be measured. After the measuring head 3 moves downward, there is a radial gap between the measuring reference surfaces 61 on the two sliding blocks 6 and the chamfered surface of the bearing inner ring 82. The two sliding blocks 6 move toward their respective radial outer sides. When the measuring head 3 moves downward to the right position, the measuring head 3 stops moving downward. The measuring reference surfaces 61 on the two sliding blocks 6 are in full contact with the chamfered surface of the bearing inner ring 82. The needle 12 of the micrometer 1 rotates to the right for a certain stroke. At this time, the state diagram of the measuring device is as shown in the figure. Figure 2 As shown, it is determined whether the reading of the needle 12 of the micrometer 1 is within the allowable tolerance range at this time, so as to screen out qualified bearing inner rings whose axial guide angle accuracy is consistent with the allowable tolerance range, and eliminate unqualified products; similarly, when the axial guide angle of the bearing inner ring 83 to be measured is less than 15°±10′, after the measuring head 3 moves down, since the angle between the measuring reference surface 61 on the two sliding blocks 6 and the vertical direction is greater than the axial guide angle of the bearing inner ring 83 to be measured, when the measuring head 3 moves down to the point where the measuring reference surface 61 on the two sliding blocks 6 contacts the chamfered surface of the bearing inner ring 83, the two sliding blocks 6 are respectively pushed inward and move toward their respective radial inner sides. When the measuring head 3 moves down to the position, the measuring head 3 stops moving down, and the needle 12 of the micrometer 1 rotates to the left by a certain stroke. At this time, the state diagram of the measuring device is as shown in Figure 5 As shown, it is determined whether the reading of the needle 12 of the micrometer 1 is within the allowable tolerance range at this time, so as to screen out qualified bearing inner rings whose axial guide angle accuracy is consistent with the allowable tolerance range and eliminate unqualified products.
[0039] Taking the batch measurement of the axial guide angles of 400 bearing inner rings as an example, it takes a total of 33 hours to measure the axial guide angles of 400 bearing inner rings using a traditional profilometer, and it takes an average of 4.95 minutes to measure the axial guide angle of a single bearing inner ring. However, using the measuring device and the measuring method of the present invention, it only takes 80 minutes to complete the full inspection of 400 bearing inner rings, and it only takes an average of 0.2 minutes to measure the axial guide angle of a single bearing inner ring, which greatly improves the measurement efficiency.
Claims
1. A device for measuring the axial guide angle of a bearing inner ring, characterized in that: The invention comprises a micrometer, a base, a measuring head and a paddle, wherein the micrometer is upright mounted on the base, the paddle is connected to the measuring rod of the micrometer, the paddle is used to drive the measuring rod to move up and down, the measuring head is fixed to the bottom end of the measuring rod, the bottom of the measuring head is elastically connected with two arched sliding blocks, each of the sliding blocks can slide laterally, the outer diameter of each sliding block is matched with the inner diameter of the inner ring of the bearing, the radial outer surface of each sliding block is a measuring reference surface, and the measuring reference surface is from top to bottom. The measuring head is arranged radially inwardly downwardly toward the radial inner side of the sliding block, and the angle between the measuring reference plane and the vertical direction is 15°±10′. A limit block for positioning the inner ring of the bearing is arranged directly below the measuring head. When measuring the axial guide angle of the inner ring of the bearing, the inner ring of the bearing is placed on the limit block, and the paddle is operated to move the measuring rod downward until the measuring reference surfaces on the two sliding blocks are in full contact with the chamfered surface of the inner ring of the bearing. At this time, the reading of the needle of the micrometer is used to determine whether the axial guide angle of the inner ring of the bearing is within the allowable tolerance range.
2. The device for measuring the axial guide angle of the inner ring of a bearing according to claim 1, characterized in that: Two slideways are horizontally arranged in the measuring head, the lower side of each slideway is communicated with a connecting groove, the upper part of each sliding block is vertically connected with a ball stud, each ball stud is passed through one of the connecting grooves, the ball head of each ball stud can be slidably arranged in one of the slideways, a spring is installed in each of the slideways, the outer end of each spring is connected to a ball head, and the inner end of each spring is connected to the measuring head.
3. The device for measuring the axial guide angle of the inner ring of a bearing according to claim 2, characterized in that: A limiting boss is integrally arranged at the center of the bottom of the measuring head, and the limiting boss is located radially inward of the two sliding blocks.
4. The device for measuring the axial guide angle of the inner ring of a bearing according to claim 3, characterized in that: The limiting boss is hemispherical, and the radial inner surface of each sliding block is provided with an inclined surface matched with the limiting boss.
5. The device for measuring the axial guide angle of the inner ring of a bearing according to claim 2, characterized in that: A cover plate is arranged on the outer side of each slideway, and the cover plate is fixed to the outer side wall of the measuring head. Each slideway is filled with grease.
6. The device for measuring the axial guide angle of the inner ring of a bearing according to claim 1, characterized in that: The bottom of the table base is integrally provided with a base plate, the limit block is fixed on the base plate by interference fit, the upper part of the limit block is integrally provided with a positioning boss, the outer diameter of the positioning boss is matched with the inner diameter of the inner ring of the bearing, and the center line of the positioning boss is on the same vertical line as the center line of the measuring head.
7. The device for measuring the axial guide angle of the inner ring of a bearing according to claim 6, characterized in that: A handle is integrally arranged on the side of the table base.
8. The device for measuring the axial guide angle of the inner ring of a bearing according to claim 1, characterized in that: A support rod is fixed to one side of the dial gauge case, the middle part of the paddle is hinged to the support rod, and the front end of the paddle is connected to the measuring rod of the dial gauge.
9. The measuring method of the axial guide angle measuring device of the bearing inner ring according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) Produce a standard bearing inner ring with an axial guide angle of 15°±10′, and produce a defective bearing inner ring part 1 with an axial guide angle of 13°±10′ and a defective bearing inner ring part 2 with an axial guide angle of 17°±10′; (2) Press the paddle downward, lift the measuring rod, place the standard part on the limit block, and then pull the paddle upward to allow the measuring rod to drive the measuring head downward. When the measuring reference surfaces on the two sliding blocks are in full contact with the chamfered surfaces of the standard part, the measuring head is limited and stops moving downward. At this time, return the needle of the micrometer to zero, and the standard value of the axial guide angle is set. (3) Press the paddle downward, lift the measuring rod, remove the standard part, place the defective part 1 on the limit block, and then pull the paddle upward to make the measuring rod drive the measuring head to move downward. When the measuring reference surfaces on the two sliding blocks are in full contact with the chamfered surface of the defective part 1, the measuring head is limited and stops moving downward. The position of the needle at this time is marked as position 1 on the dial of the micrometer. (4) Press the paddle downward, lift the measuring rod, remove the defective part 1, place the defective part 2 on the limit block, and then pull the paddle upward to allow the measuring rod to drive the measuring head downward. When the measuring reference surfaces on the two sliding blocks are in full contact with the chamfered surface of the defective part 2, the measuring head is limited and stops moving downward. The position of the needle at this time is marked as position 2 on the dial of the micrometer. Press the paddle downward again, lift the measuring rod, and remove the defective part 2. The reading between position 1 and position 2 on the dial of the micrometer is the allowable tolerance range. (5) Place the inner ring of the bearing whose axial guide angle needs to be measured on the limit block, then pull up the paddle to allow the measuring rod to drive the measuring head downward. When the measuring reference surfaces on the two sliding blocks are in full contact with the chamfered surface of the inner ring of the bearing, the measuring head is limited and stops moving downward. Based on the reading of the needle of the micrometer at this time, determine whether the axial guide angle of the inner ring of the bearing is within the allowable tolerance range.