A method for measuring the angular clearance of a double-row deep groove ball bearing and a method for fitting the bearing

Abstract

The present invention relates to the field of bearing processing, and specifically discloses a diagonal clearance measurement method and a sleeve assembly method for a double-row deep groove ball bearing. The diagonal clearance measurement method includes at least the following steps: selecting a bearing inner ring, a bearing outer ring and a specific number of rolling elements, installing the rolling elements between the bearing inner ring and the bearing outer ring, and limiting them by a retaining frame; the rolling elements are in an underfilled state at this time; measuring the radial clearance of the bearing, recorded as Gr; and calculating the diagonal clearance of the bearing through a formula. The above-mentioned diagonal clearance measurement method can achieve reliable test operations by measuring the radial clearance of the bearing in an underfilled state and indirectly calculating the diagonal clearance, providing a basis for subsequent assembly operations.

Description

Technical Field

[0001] The invention relates to the field of bearing processing, and in particular to a diagonal clearance measuring method and a sleeve fitting method of a double-row deep groove ball bearing. Background Art

[0002] Double row full complement deep groove ball bearing is a type of bearing that is filled with two rows of steel balls, has no cage, and has a ball filling angle of nearly 360°. In order to achieve full filling of the bearing, a ball filling gap is provided for each groove on the inner and outer rings of the bearing. When the ball filling gaps on the inner and outer rings are aligned, the steel balls can be fully filled through the ball filling gaps. Compared with conventional double row angular contact ball bearings, full complement double row deep groove ball bearings are more suitable for heavy load conditions of low speed swing or rotation.

[0003] The angular clearance of the bearing is an important technical indicator of a double-row full-complement deep groove ball bearing, which is used to characterize the angular stiffness and displacement accuracy performance of the bearing. The angular clearance of the double-row full-complement deep groove ball bearing can be directly measured when the rolling elements are fully loaded. The technical specification of this type of bearing stipulates the measurement method of the angular clearance of the double-row full-complement deep groove ball bearing: Place the bearing horizontally, fix the outer ring of the bearing, pass a stress-free shaft through the inner ring, and keep the two sides equidistant. Place a measuring gauge 100mm on one side of the shaft, and slowly apply a load F of 10N perpendicular to the axis at 100mm on the other side of the shaft. Record the value measured by the gauge at this time, apply F in the reverse direction, and record the value measured by the gauge again. The difference between the two gauge readings is the angular clearance of the bearing.

[0004] The above-mentioned diagonal clearance measurement method has a disadvantage. Since the bearing is double-row and fully loaded, a direct measurement method is used. If the diagonal clearance is unqualified, the bearing cannot be disassembled and replaced, and can only be directly scrapped, resulting in a high scrap rate. If the diagonal clearance of the bearing is tested when it is not fully loaded, the bearing's load capacity will be reduced and the angular stiffness will be reduced because the steel balls are not fully loaded. The measured result will be significantly different from the actual value, and the measurement accuracy will be poor.

[0005] Therefore, the purpose of this application is to provide a measurement method that is easy to operate and has reliable results for a specific bearing type, namely, double-row full complement deep groove ball bearings. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a method for measuring the diagonal clearance of a double-row deep groove ball bearing and a method for assembling the bearings. By measuring the radial clearance of the bearings in a partially filled state and indirectly calculating the diagonal clearance, reliable test operations can be performed, providing a basis for subsequent assembly operations.

[0007] In order to solve the above technical problems, the present invention provides a technical solution as follows: a method for measuring the angular clearance of a double-row deep groove ball bearing, comprising at least the following steps:

[0008] S1. Assembly: Select the inner ring of the bearing, the outer ring of the bearing and a specific number of rolling elements, install the rolling elements between the inner ring of the bearing and the outer ring of the bearing, and limit them by the cage; at this time, the rolling elements are in a state of not being fully loaded;

[0009] S2. Radial clearance measurement: measure the radial clearance of the bearing, recorded as Gr;

[0010] S3. Result post-processing: Calculate the bearing angular clearance according to the following formula:

[0011] ;

[0012] Where:

[0013] ;

[0014] ;

[0015] ;

[0016] ;

[0017] ;

[0018] ;

[0019] ;

[0020] ;

[0021] Gd: bearing angular clearance; L: distance between measuring point and bearing center;

[0022] Dwp: bearing center diameter; Dw: rolling element diameter;

[0023] ai: distance between two grooves of the inner ring of the bearing; Ri: radius of curvature of the groove of the inner ring of the bearing;

[0024] ae: distance between two grooves of the bearing outer ring; Re: radius of curvature of the bearing outer ring groove;

[0025] Gr: Bearing radial clearance.

[0026] The angular clearance measurement method of the present application can ensure the reliability of the bearing angular clearance measurement accuracy by measuring the radial clearance of the bearing in a not fully filled state and indirectly calculating the bearing angular clearance. When the measured bearing angular clearance cannot meet the design requirements, since the bearing is not fully filled during measurement, the bearing can be disassembled and assembled with spare parts of other specifications, thereby reducing the scrap rate of products and spare parts and reducing production costs.

[0027] Preferably, in step S1, the ball loading angle of the rolling body is not greater than 186°.

[0028] Preferably, in step S2, the inner ring of the bearing is fixed, and two loads in opposite directions are applied to the outer ring of the bearing in sequence to push the outer ring of the bearing to move in two corresponding directions to the extreme positions, and the relative displacement of the outer ring of the bearing between the two extreme positions is measured, which is the bearing radial clearance Gr.

[0029] Preferably, in step S3, ai=ae, L=100mm.

[0030] A method for assembling a double-row deep groove ball bearing comprises at least the following steps:

[0031] S01. Determine the threshold value: determine the acceptable range of the bearing angular clearance, with the lower limit value recorded as Gdmin and the upper limit value recorded as Gdmax; obtain the acceptable range of the bearing radial clearance according to the formula in step S3, with the lower limit value recorded as Grmin and the upper limit value recorded as Grmax;

[0032] S02. Parts measurement: measure the bottom diameter di of the bearing inner ring, the bottom diameter De of the bearing outer ring and the diameter Dw of the rolling element, and classify the bearing inner ring, bearing outer ring and rolling element according to the measurement results;

[0033] S03. Preliminary selection: Based on the calculation formula: Gr=De-di-2Dw and the qualified range of the bearing radial clearance, the bearing inner ring, bearing outer ring and rolling element assembly scheme that meet the qualified range of the bearing radial clearance are preliminarily selected;

[0034] S04. Test: For each group of initially selected bearing inner rings, bearing outer rings and rolling elements, the angular clearance measurement method described above is used to obtain a test angular clearance, which is recorded as Gd1;

[0035] S05. Fitting: Compare the tested angular clearance with the acceptable range of the bearing angular clearance.

[0036] If Gd1<Gdmin, it indicates that the angular clearance of the bearing is too small and the assembly fails; the current bearing is disassembled, and the assembly scheme is adjusted by reducing the rolling element diameter, increasing the bottom diameter of the bearing outer ring groove, or reducing the bottom diameter of the bearing inner ring groove, and steps S04 and S05 are repeated;

[0037] If Gdmin≤Gd1≤Gdmax, it means the bearing angular clearance meets the design requirements and the bearing is assembled.

[0038] If Gdmax<Gd1, it indicates that the angular clearance of the bearing is too large and the assembly fails; the current bearing is disassembled, and the assembly scheme is adjusted by at least one of increasing the rolling element diameter, reducing the bottom diameter of the bearing outer ring groove, and increasing the bottom diameter of the bearing inner ring groove, and steps S04 and S05 are repeated.

[0039] Preferably, in step S01, the lower limit value of the bearing angular clearance Gdmin=0.

[0040] Preferably, in step S03, when initially selecting a combination scheme of the bearing inner ring, the bearing outer ring and the rolling elements, each bearing inner ring is used as a reference to combine the rolling elements and the bearing outer ring of the corresponding category.

[0041] Preferably, in step S05, when the assembly fails, the following steps are used to adjust the assembly scheme:

[0042] S051. Based on the current bearing inner ring bottom diameter and bearing outer ring bottom diameter, adjust the assembly plan by adjusting the rolling element diameter category; when all the rolling element categories to be selected cannot meet the fitting requirements, based on the current bearing inner ring bottom diameter and rolling element diameter, adjust the assembly plan by adjusting the bearing outer ring groove bottom diameter category.

[0043] Preferably, in step S02, di, De and Dw are all graded with 2 μm as one level; in step S051, when the fitting fails, the assembly scheme is adjusted in a step-by-step manner.

[0044] Preferably, in step S051, when all the bottom diameter categories of the selected bearing outer rings cannot meet the fitting requirements, the fitting is determined to have failed, and the current bearing inner ring processing is unqualified or the bottom diameter measurement of the current bearing inner ring is unqualified, and the current bearing inner ring is scrapped. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the structure of a double-row deep groove ball bearing in a non-deflected state;

[0046] Figure 2 It is a half-section view of a double-row deep groove ball bearing in an undeflected state;

[0047] Figure 3 It is a structural schematic diagram of a double row deep groove ball bearing in a deflected state;

[0048] Figure 4 It is a half-section view of the double-row deep groove ball bearing in deflection state;

[0049] Figure 5 for Figure 4 A partial enlarged view of the M in the middle;

[0050] Figure 6It is a schematic diagram of the change of the center position of the inner ring groove of the double-row deep groove ball bearing under the deflection state;

[0051] Figure 7 It is a schematic diagram of the change in the center position of the outer ring groove of the double-row deep groove ball bearing when the bearing is deflected. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0053] Example

[0054] A method for measuring the angular clearance of a double-row deep groove ball bearing comprises at least the following steps:

[0055] S1. Assembly: Select the inner ring, outer ring and a specific number of rolling elements, install the rolling elements between the inner ring and outer ring, and limit them by the cage. At this time, the rolling elements are not fully filled. Specifically, in order to ensure that the bearing is not fully filled, the ball loading angle of the rolling elements is not greater than 186°.

[0056] S2. Radial clearance measurement: Measure the radial clearance of the bearing, recorded as Gr.

[0057] Specifically, the measurement steps of the bearing radial clearance include: fixing the inner ring of the bearing, applying two loads in opposite directions to the outer ring of the bearing in turn, pushing the outer ring of the bearing to move in two corresponding directions to the limit positions, and measuring the relative displacement of the outer ring of the bearing between the two limit positions, which is the bearing radial clearance Gr.

[0058] S3. Result post-processing: Calculate the bearing angular clearance according to the following formula:

[0059] ;

[0060] Where:

[0061] ;

[0062] ;

[0063] ;

[0064] ;

[0065] ;

[0066] ;

[0067] ;

[0068] ;

[0069] Gd: bearing angular clearance; L: distance between measuring point and bearing center;

[0070] Dwp: bearing center diameter; Dw: rolling element diameter;

[0071] ai: distance between two grooves of the inner ring of the bearing; Ri: radius of curvature of the groove of the inner ring of the bearing;

[0072] ae: distance between two grooves of the bearing outer ring; Re: radius of curvature of the bearing outer ring groove;

[0073] Gr: Bearing radial clearance.

[0074] As a specific implementation method, in the above formula, ai=ae, L=100mm.

[0075] The angular clearance measurement method of the present application can ensure the reliability of the bearing angular clearance measurement accuracy by measuring the radial clearance of the bearing in a not fully filled state and indirectly calculating the bearing angular clearance. When the measured bearing angular clearance cannot meet the design requirements, since the bearing is not fully filled during measurement, the bearing can be disassembled and assembled with spare parts of other specifications, thereby reducing the scrap rate of products and spare parts and reducing production costs.

[0076] The following is a detailed introduction to the derivation of the bearing angular clearance calculation formula in step S3:

[0077] like Figure 1 and Figure 2 The figure shows the structure of a double row deep groove ball bearing without deflection. Figure 2 As shown, the following is a description of each parameter:

[0078] Dwp: bearing center diameter; Dw: rolling element diameter;

[0079] ai: distance between two grooves of the inner ring of the bearing; Ri: radius of curvature of the groove of the inner ring of the bearing;

[0080] ae: distance between two grooves of the bearing outer ring; Re: radius of curvature of the bearing outer ring groove;

[0081] Gr: radial clearance of the bearing; di: bottom diameter of the inner ring groove of the bearing;

[0082] De: bottom diameter of the bearing outer ring groove.

[0083] Before the inner ring and outer ring are deflected, the center O of the rolling element is located at the center diameter of the bearing, point E is the center of curvature of the inner ring groove, point F is the center of curvature of the outer ring groove, and point P is the center point of the bearing. After the bearing is assembled, the radial activity space of the rolling element between the inner ring and the outer ring of the bearing is the radial clearance Gr of the bearing. Assume that after the assembly is completed, the inner ring, outer ring and rolling element of the bearing are symmetrically arranged relative to the axis, such as Figure 2 As shown in the figure, the distance between the inner ring groove, outer ring groove and rolling element is 0.25 times the radial clearance of the bearing.

[0084] like Figure 3-Figure 5 The figure shows the structure of a double-row deep groove ball bearing in a deflected state. When the inner ring and outer ring of the bearing are deflected, assuming that the position of the rolling element remains unchanged, the inner ring and outer ring of the bearing rotate relative to the rolling element around the center point P of the bearing. In the deflected state, the gap between the inner ring and outer ring grooves of the bearing and the rolling element is eliminated, and the center of curvature E of the inner ring groove of the bearing moves along circle O1 to point U. At this time, the deflection angle of the inner ring of the bearing is α; the center of curvature F of the outer ring groove of the bearing moves along circle O2 to point V, and the deflection angle of the outer ring of the bearing is β. Assuming that the distance between the measuring point and the center point P of the bearing is L, the diagonal clearance of the inner ring of the bearing is expressed as α*L, and the diagonal clearance of the outer ring of the bearing is expressed as β*L, then the overall diagonal clearance of the bearing is:

[0085] .

[0086] 1) Analyze the inner ring of the bearing alone, Figure 6 Schematic diagram of the position change of the bearing inner ring deflection.

[0087] In ΔEOP, ∠EPO is ∠1, and ∠1 is calculated as:

[0088] ;

[0089] In ΔUOP, ∠UPO is recorded as ∠2, and ∠2 is calculated as:

[0090] ;

[0091] Where:

[0092] The distance between the center E of the inner raceway curvature radius before deflection and the center O of the steel ball is OE. The OE to be calculated is:

[0093] ;

[0094] The center of the inner raceway curvature radius is E, which is U after deflection. The distance from the inner race deflection center P is EP and UP. EP and UP are obtained as follows:

[0095] ;

[0096] Substituting into the OE relationship, we get:

[0097] ;

[0098] The distance between the center U of the inner raceway's radius of curvature after deflection and the center O of the steel ball is OU. The calculated OU is:

[0099] ;

[0100] In double row deep groove ball bearings, ae=ai, the distance between the center of the ball and P is OP, and OP is obtained:

[0101]

[0102] In summary, we have

[0103]

[0104]

[0105] make

[0106] ;

[0107] ;

[0108] ;

[0109] Then there is

[0110]

[0111] 2) Analyze the outer ring of the bearing alone, Figure 7 Schematic diagram of the position change of the bearing outer ring deflection.

[0112] In ΔVOP, ∠OPV is ∠4, and ∠4 is calculated as:

[0113] ;

[0114] In ΔFOP, let ∠OPF be ∠3, and calculate ∠3:

[0115] ;

[0116] Where:

[0117] The distance between the center F of the outer raceway curvature radius before deflection and the center O of the steel ball is OF. Find OF:

[0118] ;

[0119] The center of the outer ring channel curvature radius is F, and after deflection it is V. The distance from the outer ring deflection center P is VP and FP. VP and FP are obtained as follows:

[0120] ;

[0121] Substituting into the OF relation, we get:

[0122] ;

[0123] After the outer raceway is deflected, the distance between the center V of the curvature radius and the center O of the steel ball is OV. The OV to be calculated is:

[0124] ;

[0125] Then we have:

[0126]

[0127]

[0128] make

[0129] ;

[0130] ;

[0131] ;

[0132] Then there is

[0133] ;

[0134] 3) The diagonal clearance Gd of double-row full-fill deep groove ball is:

[0135] .

[0136] It should be noted that in measurement practice, the parameters of bearing radial clearance Gr, bearing inner ring groove bottom diameter di, rolling element diameter Dw and bearing outer ring groove bottom diameter De are usually obtained through actual turning, and other parameters can be directly used for calculation by referring to the design parameters.

[0137] A method for assembling a double-row deep groove ball bearing comprises at least the following steps:

[0138] S01. Determine the threshold value: determine the acceptable range of the bearing angular clearance, with the lower limit value recorded as Gdmin and the upper limit value recorded as Gdmax; according to the formula in step S3, obtain the acceptable range of the bearing radial clearance, with the lower limit value recorded as Grmin and the upper limit value recorded as Grmax. It should be noted that in some bearing standards, the lower limit value of the bearing angular clearance is not limited, that is, under specific standard requirements, the lower limit value of the bearing angular clearance Gdmin=0.

[0139] S02. Parts measurement: Measure the bottom diameter di of the inner ring of the bearing, the bottom diameter De of the outer ring of the bearing and the diameter Dw of the rolling element, and classify the inner ring of the bearing, the outer ring of the bearing and the rolling element according to the measurement results. Specifically, di, De and Dw are graded in 2μm steps, and each level is a category.

[0140] S03. Preliminary selection: Based on the calculation formula: Gr=De-di-2Dw, and the qualified range of the bearing radial clearance, preliminarily select the bearing inner ring, bearing outer ring and rolling element combination that meet the qualified range of the bearing radial clearance.

[0141] Specifically, when initially selecting a combination scheme of a bearing inner ring, a bearing outer ring and a rolling element, each bearing inner ring is used as a reference to combine rolling elements and bearing outer rings of corresponding categories.

[0142] S04. Test: For each initially selected set of bearing inner rings, bearing outer rings and rolling elements, the angular clearance measurement method described above is used to obtain a test angular clearance, recorded as Gd1.

[0143] S05. Fitting: Compare the tested angular clearance with the acceptable range of the bearing angular clearance.

[0144] If Gd1<Gdmin, it indicates that the angular clearance of the bearing is too small and the assembly fails; the current bearing is disassembled, and the assembly scheme is adjusted by reducing the rolling element diameter, increasing the bottom diameter of the bearing outer ring groove, or reducing the bottom diameter of the bearing inner ring groove, and steps S04 and S05 are repeated;

[0145] If Gdmin≤Gd1≤Gdmax, it means the bearing angular clearance meets the design requirements and the bearing is assembled.

[0146] If Gdmax<Gd1, it indicates that the angular clearance of the bearing is too large and the assembly fails; the current bearing is disassembled, and the assembly scheme is adjusted by at least one of increasing the rolling element diameter, reducing the bottom diameter of the bearing outer ring groove, and increasing the bottom diameter of the bearing inner ring groove, and steps S04 and S05 are repeated.

[0147] Furthermore, in step S05, when the assembly fails, the following steps are used to adjust the assembly scheme:

[0148] S051. Adjust the assembly scheme by adjusting the rolling element diameter category based on the current bearing inner ring bottom diameter and bearing outer ring bottom diameter. When all the rolling element categories to be selected cannot meet the fitting requirements, adjust the assembly scheme by adjusting the bearing outer ring groove bottom diameter category based on the current bearing inner ring bottom diameter and rolling element diameter.

[0149] Specifically, when the assembly fails, the assembly plan is adjusted in a step-by-step manner.

[0150] Specifically, when all the bottom diameter categories of the selected bearing outer rings cannot meet the fitting requirements, the fitting is determined to have failed, and the current bearing inner ring processing is unqualified or the bottom diameter measurement of the current bearing inner ring is unqualified, and the current bearing inner ring is scrapped.

[0151] In short, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for measuring the angular clearance of a double-row deep groove ball bearing, characterized in that: At least the following steps are included: S1. Assembly: Select the inner ring, outer ring and a specific number of rolling elements, install the rolling elements between the inner ring and outer ring, and limit them with the cage; at this time, the rolling elements are not fully loaded; S2. Radial clearance measurement: measure the radial clearance of the bearing, recorded as Gr; S3. Result post-processing: Calculate the bearing angular clearance according to the following formula: ； Where: ； ； ； ； ； ； ； ； Gd: bearing angular clearance; L: distance between measuring point and bearing center; Dwp: bearing center diameter; Dw: rolling element diameter; ai: distance between two grooves of the inner ring of the bearing; Ri: radius of curvature of the groove of the inner ring of the bearing; ae: distance between two grooves of the bearing outer ring; Re: radius of curvature of the groove of the bearing outer ring; Gr: Bearing radial clearance.

2. The method for measuring angular clearance according to claim 1, characterized in that: In step S1, the ball filling angle of the rolling body is not greater than 186°.

3. The method for measuring angular clearance according to claim 1, characterized in that: In step S2, the inner ring of the bearing is fixed, and two loads in opposite directions are applied to the outer ring of the bearing in turn, pushing the outer ring of the bearing to move in the corresponding two directions to the limit positions, and measuring the relative displacement of the outer ring of the bearing between the two limit positions, which is the bearing radial clearance Gr.

4. The method for measuring angular clearance according to claim 1, characterized in that: In step S3, ai=ae, L=100mm.

5. A method for assembling a double row deep groove ball bearing, characterized in that: At least the following steps are included: S01. Threshold determination: determine the acceptable range of the bearing angular clearance, with the lower limit value being denoted as Gdmin and the upper limit value being denoted as Gdmax; obtain the acceptable range of the bearing radial clearance according to the formula in step S3 of claim 1, with the lower limit value being denoted as Grmin and the upper limit value being denoted as Grmax; S02. Parts measurement: measure the bottom diameter di of the bearing inner ring, the bottom diameter De of the bearing outer ring and the diameter Dw of the rolling element, and classify the bearing inner ring, bearing outer ring and rolling element according to the measurement results; S03. Preliminary selection: Based on the calculation formula: Gr=De-di-2Dw and the qualified range of the bearing radial clearance, the bearing inner ring, bearing outer ring and rolling element assembly scheme that meet the qualified range of the bearing radial clearance are preliminarily selected; S04. Test: for each group of initially selected bearing inner rings, bearing outer rings and rolling elements, a test angular clearance is obtained by using the angular clearance measurement method described in any one of claims 1 to 4, denoted as Gd1; S05. Fitting: Compare the tested angular clearance with the acceptable range of the bearing angular clearance. If Gd1<Gdmin, it indicates that the angular clearance of the bearing is too small and the assembly fails; the current bearing is disassembled, and the assembly scheme is adjusted by reducing the rolling element diameter, increasing the bottom diameter of the bearing outer ring groove, or reducing the bottom diameter of the bearing inner ring groove, and steps S04 and S05 are repeated; If Gdmin≤Gd1≤Gdmax, it means the bearing angular clearance meets the design requirements and the bearing is assembled. If Gdmax<Gd1, it indicates that the angular clearance of the bearing is too large and the assembly fails; the current bearing is disassembled, and the assembly scheme is adjusted by at least one of increasing the rolling element diameter, reducing the bottom diameter of the bearing outer ring groove, and increasing the bottom diameter of the bearing inner ring groove, and steps S04 and S05 are repeated.

6. The method for assembling a sleeve according to claim 5, characterized in that: In step S01 , the lower limit value of the bearing angular clearance Gdmin=0.

7. The method for assembling a sleeve according to claim 5, characterized in that: In step S03, when initially selecting a combination scheme of a bearing inner ring, a bearing outer ring and rolling elements, each bearing inner ring is used as a reference to combine rolling elements and bearing outer rings of corresponding categories.

8. The method for assembling a sleeve according to any one of claims 5 to 7, characterized in that: In step S05, when the assembly fails, the following steps are used to adjust the assembly scheme: S051. Based on the current bearing inner ring bottom diameter and bearing outer ring bottom diameter, adjust the assembly plan by adjusting the rolling element diameter category; when all the rolling element categories to be selected cannot meet the fitting requirements, based on the current bearing inner ring bottom diameter and rolling element diameter, adjust the assembly plan by adjusting the bearing outer ring groove bottom diameter category.

9. The method for assembling a sleeve according to claim 8, characterized in that: In step S02, di, De and Dw are all graded with 2 μm as one level; in step S051, when the fitting fails, the assembly scheme is adjusted in a step-by-step manner.

10. The method for assembling a sleeve according to claim 8, characterized in that: In step S051, when all the bottom diameter categories of the selected bearing outer rings cannot meet the fitting requirements, it is determined that the fitting has failed, and the current bearing inner ring processing is unqualified or the bottom diameter measurement of the current bearing inner ring is unqualified, and the current bearing inner ring is scrapped.

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