Method for testing pre-tightening force of angular contact ball bearing and accessory

Abstract

The application provides a kind of angular contact ball bearing pre-tightening force test method and accessory, wherein the test method includes: measuring the thickness of inner spacer ring and the thickness of outer spacer ring respectively, then calculating the thickness difference C of inner spacer ring and outer spacer ring;Measure the first height difference A1 of the inner ring and the outer ring of the first angular contact ball bearing, measure the second height difference A2 of the inner ring and the outer ring of the second angular contact ball bearing;Under the action of designed pre-tightening force, measure the first displacement B1 of the inner ring of the first angular contact ball bearing relative to the outer ring, measure the second displacement B2 of the inner ring of the second angular contact ball bearing relative to the outer ring;Calculate whether the thickness difference C, the first height difference A1, the second height difference A2, the first displacement B1 and the second displacement B2 satisfy B1+B2=A1+A2+C, and then know whether angular contact ball bearing assembly meets the requirements.The application is simple to test, easy to operate, and has high test precision.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of bearings, and in particular to a method and accessories for testing the preload force of an angular contact ball bearing. Background Art

[0002] The spatial high-precision tracking turntable belongs to a high-precision bearing support system. The angular contact ball bearing preload is a key design parameter of the rotating mechanism shaft system of the spatial high-precision tracking turntable. Its size plays a decisive role in the stiffness, rotation accuracy, friction, contact stress and other indicators of the rotating mechanism shaft system, thereby affecting the dynamic characteristics, driving ability, speed stability and life of the entire tracking turntable.

[0003] Due to the particularity of aerospace products and the fact that multiple reciprocating disassembly and assembly of the shaft system is not allowed during the assembly stage, during the design stage of the high-precision space tracking turntable, designers will calculate the precise angular contact ball bearing preload based on actual working conditions such as operating speed, working load, and operating environment, and put forward precise requirements for the angular contact ball bearing preload index.

[0004] In order to ensure the high reliability and development progress of aerospace products, it is necessary to retest the preload of purchased angular contact ball bearings in order to detect products that do not meet design requirements as early as possible. At present, the angular contact ball bearings used in engineering projects are all unpaired bearings. Before use, a simple estimate of the preload of the angular contact ball bearings must be made based on the accuracy of the rotating mechanism shaft system and friction. There are two estimation methods: one is the empirical method, and the other is to calculate the preload or axial deformation of the angular contact ball bearing based on the axial load. Both estimation methods require repeated disassembly and assembly of bearings or related components such as sleeves to adjust the clearance during the test of the preload of the angular contact ball bearings. This has low work efficiency, high labor intensity, complex operation links, and certain limitations. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method and accessories for testing the preload force of an angular contact ball bearing, which are simple to test, easy to operate and have high test accuracy.

[0006] To solve the above technical problems, in a first aspect, the present invention provides a method for testing the preload force of an angular contact ball bearing, which is applied to an angular contact ball bearing assembly, wherein the angular contact ball bearing assembly includes a first angular contact ball bearing, a second angular contact ball bearing, an inner spacer, and an outer spacer. The method comprises: measuring the thickness of the inner spacer and the thickness of the outer spacer, respectively, and then calculating the thickness difference C between the inner spacer and the outer spacer; measuring a first height difference A1 between the inner ring and the outer ring of the first angular contact ball bearing, and measuring a second height difference A2 between the inner ring and the outer ring of the second angular contact ball bearing; measuring a first displacement B1 generated by the inner ring of the first angular contact ball bearing relative to the outer ring under the action of a designed preload force, and measuring a second displacement B2 generated by the inner ring of the second angular contact ball bearing relative to the outer ring under the action of the designed preload force; and calculating whether the thickness difference C, the first height difference A1, the second height difference A2, the first displacement B1, and the second displacement B2 satisfy B1+B2=A1+A2+C, thereby determining whether the angular contact ball bearing assembly meets the requirements.

[0007] Optionally, a micrometer or a height gauge is used to measure the thickness difference C, the first height difference A1, the second height difference A2, the first displacement B1 and / or the second displacement B2.

[0008] Optionally, when measuring the thickness difference C, the first height difference A1, the second height difference A2, the first displacement B1 and / or the second displacement B2, a final measurement value is obtained by performing multiple measurements and calculating an average value.

[0009] Optionally, the steps of measuring the first height difference A1 between the inner ring and the outer ring of the first angular contact ball bearing and measuring the second height difference A2 between the inner ring and the outer ring of the second angular contact ball bearing include: placing the first angular contact ball bearing with its opening downward on a support to support its inner ring, and placing the support on a flat plate; placing a lever micrometer on the flat plate so that the needle of the lever micrometer is aligned and in contact with the outer ring of the first angular contact ball bearing, and clearing the lever micrometer; pushing the lever micrometer so that the needle of the lever micrometer is aligned and in contact with the inner ring of the first angular contact ball bearing, and the current reading of the lever micrometer is the first height difference A1 between the inner ring and the outer ring of the first angular contact ball bearing at the measuring point.

[0010] Optionally, the steps of measuring the first height difference A1 between the inner ring and the outer ring of the first angular contact ball bearing and measuring the second height difference A2 between the inner ring and the outer ring of the second angular contact ball bearing further include: placing the second angular contact ball bearing with its opening downward on a support to support its inner ring, and placing the support on a flat plate; placing a lever micrometer on the flat plate so that the needle of the lever micrometer is aligned and in contact with the outer ring of the second angular contact ball bearing, and clearing the lever micrometer; pushing the lever micrometer so that the needle of the lever micrometer is aligned and in contact with the inner ring of the second angular contact ball bearing, and the current reading of the lever micrometer is the second height difference A2 between the inner ring and the outer ring of the second angular contact ball bearing at the measuring point.

[0011] Optionally, the steps of measuring the first displacement B1 of the inner ring of the first angular contact ball bearing relative to the outer ring under the action of the designed preload, and measuring the second displacement B2 of the inner ring of the second angular contact ball bearing relative to the outer ring under the action of the designed preload, include: placing the first angular contact ball bearing with the opening facing upward on a tooling; aligning the needle of the lever micrometer to contact the inner ring of the first angular contact ball bearing, marking the position where the needle of the lever micrometer is aligned with the contact, and then clearing the lever micrometer; placing at least one counterweight on the end face of the inner ring of the first angular contact ball bearing, recording the reading of the lever micrometer, and stopping loading until the loaded counterweight is greater than the designed preload; when the total mass of each counterweight is equal to the designed preload, the reading of the lever micrometer is the first displacement B1.

[0012] Optionally, the steps of measuring the first displacement B1 of the inner ring of the first angular contact ball bearing relative to the outer ring under the action of the designed preload, and measuring the second displacement B2 of the inner ring of the second angular contact ball bearing relative to the outer ring under the action of the designed preload, further include: placing the second angular contact ball bearing with the opening facing upward on the tooling; aligning the needle of the lever micrometer to contact the inner ring of the second angular contact ball bearing, marking the position where the needle of the lever micrometer is aligned with the contact, and then clearing the lever micrometer; placing at least one counterweight on the end face of the inner ring of the second angular contact ball bearing, recording the reading of the lever micrometer, and stopping loading until the loaded counterweight is greater than the designed preload. When the total mass of each counterweight is equal to the designed preload, the reading of the lever micrometer is the second displacement B2.

[0013] Optionally, the mass of a single counterweight is smaller than the allowable error value of the design value of the measured angular contact ball bearing preload, and the total mass of all the counterweights is greater than 10% of the design value of the measured angular contact ball bearing preload.

[0014] Optionally, it also includes: measuring the actual preload force of the angular contact ball bearing assembly, measuring the first displacement B1 of the inner ring of the first angular contact ball bearing relative to the outer ring under the actual preload force, and measuring the second displacement B2 of the inner ring of the second angular contact ball bearing relative to the outer ring under the designed preload force.

[0015] Optionally, measuring the actual preload force of the angular contact ball bearing assembly includes: assembling the angular contact ball bearing shaft assembly according to the actual installation method and placing it on the tooling, and gradually loading counterweights onto the inner ring of the first angular contact ball bearing in the angular contact ball bearing shaft assembly. When the load increases to the resistance, the total weight of all loaded counterweights is the actual preload force of the angular contact ball bearing assembly.

[0016] In a second aspect, the present invention provides an angular contact ball bearing preload test accessory, comprising: a first main body, the first main body being a hollow cylindrical structure, the upper end face of the first main body having a placement portion, the placement portion being a stepped surface for supporting the outer ring of the angular contact ball bearing to be tested, and a plurality of test holes being provided on the side wall of the first main body.

[0017] In a third aspect, the present invention provides an angular contact ball bearing preload test accessory, comprising: a second main body, the upper end of the second main body having a first table surface, a second table surface and a third table surface in sequence from the outside to the inside, and the height of the first table surface is smaller than the height of the second table surface, and the height of the second table surface is smaller than the height of the third table surface.

[0018] Compared with the prior art, the present invention has the following advantages: first, the thickness of the inner spacer and the thickness of the outer spacer are measured respectively, and the thickness difference C between the inner spacer and the outer spacer is calculated; then, the first height difference A1 of the inner ring and the outer ring of the first angular contact ball bearing is measured, and the second height difference A2 of the inner ring and the outer ring of the second angular contact ball bearing is measured; then, under the action of the designed preload force, the first displacement B1 of the inner ring of the first angular contact ball bearing relative to the outer ring is measured; and under the action of the designed preload force, the second displacement B2 of the inner ring of the second angular contact ball bearing relative to the outer ring is measured; finally, whether the thickness difference C, the first height difference A1, the second height difference A2, the first displacement B1 and the second displacement B2 satisfy B1+B2=A1+A2+C is calculated, thereby determining whether the angular contact ball bearing assembly meets the requirements. The present invention has the advantages of simple testing, convenient operation, and high testing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are included to provide a further understanding of the present application. They are incorporated into and constitute a part of this application. The accompanying drawings illustrate embodiments of the present application and, together with this specification, serve to explain the principles of the present application. In the accompanying drawings:

[0020] Figure 11 is a schematic diagram of the installation of an angular contact ball shaft assembly according to an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of a height difference test in a method for testing the preload force of an angular contact ball bearing according to an embodiment of the present invention;

[0022] Figure 3 It is a schematic diagram of displacement testing in a method for testing the preload force of an angular contact ball bearing according to an embodiment of the present invention.

[0023] Figure 4 This is a schematic diagram of a combined test method for testing the preload force of an angular contact ball bearing according to an embodiment of the present invention;

[0024] Figure 5 This is a schematic structural diagram of an angular contact ball bearing preload force test accessory according to an embodiment of the present invention;

[0025] Figure 6 It is a structural schematic diagram of another angular contact ball bearing preload force test accessory according to an embodiment of the present invention.

[0026] In the picture:

[0027] 10-first angular contact ball bearing, 101-first outer ring, 102-first inner ring;

[0028] 20-second angular contact ball bearing, 201-second outer ring, 202-second inner ring;

[0029] 30-inner spacer;

[0030] 40-outer spacer;

[0031] 50-tablet;

[0032] 60-support;

[0033] 70-first tooling, 701-first main body, 702-test hole, 703-piece placement part;

[0034] 80-second tooling, 801-first table, 802-second table, 803-third table, 804-second body;

[0035] 90-Counterweight. DETAILED DESCRIPTION

[0036] To more clearly illustrate the technical solutions of the embodiments of this application, the following is a brief introduction to the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0037] In the description of this application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of this application; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0038] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is solely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. Furthermore, while the terms used in this application are selected from commonly known and commonly used terms, some terms mentioned in this specification may have been selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant sections of this description. Furthermore, this application should be understood not only by the actual terms used, but also by the meaning implied by each term.

[0039] Flowcharts are used in this application to illustrate the operations performed by systems according to embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the various steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0040] refer to Figure 1 As shown, Figure 1 The angular contact ball bearing assembly and support 60 for back-to-back use include a first angular contact bearing 10, an inner spacer 30, an outer spacer 40, a second angular contact ball bearing 20, and the support 60. The first and second angular contact ball bearings 10 and 20 are preloaded using a positioning preload mechanism, with the inner spacer 30 and outer spacer 40 positioned between the first and second angular contact ball bearings 10 and 20. The upper end surface of the support 60 has a circular protrusion that supports the inner ring of the second angular contact ball bearing 20.

[0041] In the initial state, there is a certain gap α between the inner spacer 30 and the inner ring of the first angular contact ball bearing 10. At this time, when force F is applied to the inner ring of the first angular contact ball bearing 10, the gap α will continue to decrease with the increase of force F. The force F acts entirely between the steel balls and the raceway of the first angular contact ball bearing 10, causing the steel balls and the raceway to generate an interaction force, that is, a preload force, until the gap α is reduced to 0, that is, after the inner spacer 30 and the inner ring of the first angular contact ball bearing 10 contact each other, the force F continues to increase, which will cause the inner ring of the first angular contact ball bearing 10 and the inner spacer 30 to elastically deform, and the preload force of the angular contact ball shaft assembly increases very little. Therefore, it can be considered that after the inner ring of the first angular contact ball bearing 10 presses the inner spacer 30, the preload force of the angular contact ball shaft assembly tends to be stable.

[0042] The principle of generating preload in an angular contact ball bearing assembly reveals that the initial clearance between the inner ring of the first angular contact ball bearing 10 and the inner spacer 30 determines the preload. This initial clearance comprises the (initial) height difference A1 between the inner and outer rings of the first angular contact ball bearing 10, the (initial) height difference A2 between the inner and outer rings of the second angular contact ball bearing 20, and the thickness difference C between the inner and outer spacer 30 and 40. The initial clearance is equal to the sum of the displacement B1 of the inner ring of the first angular contact ball bearing 10 relative to the outer ring and the displacement B2 of the inner ring of the second angular contact ball bearing 20 relative to the outer ring under the design preload, i.e., B1 + B2 = A1 + A2 + C. It should be noted that in actual calculations, the equation B1 + B2 = A1 + A2 + C may not be completely accurate, and there may be some error. However, as long as the error is within an acceptable range, it is considered to meet the equation B1 + B2 = A1 + A2 + C.

[0043] It can be seen from the above formula that by measuring the thickness difference C between the inner spacer 30 and the outer spacer 40, the initial height difference A1 between the inner ring and the outer ring of the first angular contact ball bearing 10, the initial height difference A2 between the inner ring and the outer ring of the second angular contact ball bearing 20, and the displacement B1 of the inner ring of the first angular contact ball bearing 10 relative to the outer ring under the action of the designed preload, and the displacement B2 of the inner ring of the second angular contact ball bearing 20 relative to the outer ring, it is possible to check whether the preload force of the angular contact ball shaft assembly meets the design requirements.

[0044] Therefore, this embodiment provides an angular contact ball bearing preload test method, which is applied to an angular contact ball bearing assembly, wherein the angular contact ball bearing assembly includes a first angular contact ball bearing 10, a second angular contact ball bearing 20, an inner spacer 30, and an outer spacer 40. The method includes: measuring the thickness of the inner spacer 30 and the thickness of the outer spacer 40, respectively, and then calculating the thickness difference C between the inner spacer 30 and the outer spacer 40; measuring a first height difference A1 between the inner ring and the outer ring of the first angular contact ball bearing 10, and measuring a second height difference A2 between the inner ring and the outer ring of the second angular contact ball bearing 20; measuring a first displacement B1 of the inner ring of the first angular contact ball bearing 10 relative to the outer ring under the action of a designed preload, and measuring a second displacement B2 of the inner ring of the second angular contact ball bearing 20 relative to the outer ring under the action of the designed preload; and calculating whether the thickness difference C, the first height difference A1, the second height difference A2, the first displacement B1, and the second displacement B2 satisfy B1+B2=A1+A2+C, thereby determining whether the angular contact ball bearing assembly meets the requirements.

[0045] In one example, a micrometer or a height gauge is used to measure the degree difference C, the first height difference A1 , the second height difference A2 , the first displacement B1 and / or the second displacement B2 .

[0046] A micrometer consists of a fixed sleeve and a rotatable micrometer screw with a spiral line engraved on it. With each rotation, the screw moves a fixed distance, usually 0.5 mm or 1 mm. When using a micrometer, it is necessary to first calibrate the zero point, then measure the size of the workpiece, and read the scales on the fixed sleeve and the micrometer screw to obtain accurate measurement results. Altimeters are mainly based on laser ranging technology, which involves emitting a laser beam at the target object and measuring the time it takes for the laser to return to the target to calculate the distance. The altimeter uses a built-in laser generator to generate a laser beam, which is then irradiated onto the target object and reflected by the target before being received by a receiver. After receiving the laser, the receiver sends a signal back to the radar system and calculates the position of the target point from the time the laser is emitted to the time the signal is received, thereby measuring the vertical distance between the target object and the altimeter. In this embodiment, either a micrometer or an altimeter can meet the testing requirements of angular contact ball bearing assemblies.

[0047] In one example, when measuring the thickness difference C, the first height difference A1, the second height difference A2, the first displacement B1 and / or the second displacement B2, a final measurement value is obtained by taking multiple measurements and calculating an average value.

[0048] In experiments or measurements, errors may be caused by a variety of random factors, and the impact of these factors may be different in different measurements. When multiple measurements are taken and averaged, these random errors often appear in different ways in different measurements, thus offsetting each other in the averaging process, making the average value closer to the true value. For example, when measuring the thickness difference C, to ensure measurement accuracy, the thickness of the inner spacer 30 is measured at four evenly distributed locations along the circumference of the inner spacer 30, and the average of the four measurements is taken as the thickness value of the inner spacer 30; similarly, the thickness of the outer spacer 40 is measured at four evenly distributed locations along the circumference of the outer spacer 40, and the average of the four measurements is taken as the thickness value of the outer spacer 40.

[0049] refer to Figure 2 As shown, in an example, the steps of measuring the first height difference A1 between the inner ring (i.e., the first inner ring 102) and the outer ring (i.e., the first outer ring 101) of the first angular contact ball bearing 10, and measuring the second height difference A2 between the inner ring (i.e., the second inner ring 202) and the outer ring (i.e., the second outer ring 201) of the second angular contact ball bearing 20 include: placing the first angular contact ball bearing 10 with its opening downward on the support 60 to support its inner ring, and placing the support 60 on the flat plate 50; placing the lever micrometer on the flat plate 50, so that the needle of the lever micrometer is aligned and in contact with the outer ring of the first angular contact ball bearing 10, and clearing the lever micrometer to zero; pushing the lever micrometer so that the needle of the lever micrometer is aligned and in contact with the inner ring of the first angular contact ball bearing 10, and the current reading of the lever micrometer is the first height difference A1 between the inner ring and the outer ring of the first angular contact ball bearing 10 at the measuring point.

[0050] Based on the same test method as the above-mentioned first height difference A1, the first height difference A1 between the inner ring and the outer ring of the first angular contact ball bearing 10 is measured, and the second height difference A2 between the inner ring and the outer ring of the second angular contact ball bearing 20 is measured, which also includes: placing the second angular contact ball bearing 20 with its opening downward on the support 60 to support its inner ring, and placing the support 60 on the flat plate 50; placing the lever micrometer on the flat plate 50, so that the needle of the lever micrometer is aligned and in contact with the outer ring of the second angular contact ball bearing 20, and clearing the lever micrometer; pushing the lever micrometer so that the needle of the lever micrometer is aligned and in contact with the inner ring of the second angular contact ball bearing 20, and the current reading of the lever micrometer is the second height difference A2 between the inner ring and the outer ring of the second angular contact ball bearing 20 at the measuring point.

[0051] refer to Figure 3As shown, in an example, the steps of measuring the first displacement B1 of the inner ring of the first angular contact ball bearing 10 relative to the outer ring under the action of the designed preload and measuring the second displacement B2 of the inner ring of the second angular contact ball bearing 20 relative to the outer ring under the action of the designed preload include: placing the first angular contact ball bearing 10 with the opening facing upward on the corresponding tooling; aligning the needle of the lever micrometer to contact the inner ring of the first angular contact ball bearing 10, marking the position where the needle of the lever micrometer is aligned with the contact, and then clearing the lever micrometer; placing at least one counterweight 90 on the end face of the inner ring of the first angular contact ball bearing 10, recording the reading of the lever micrometer, and stopping loading until the loaded counterweight is greater than the designed preload. When the total mass of the counterweights 90 is equal to the designed preload, the reading of the lever micrometer is the first displacement B1.

[0052] Based on the same test method as the first displacement B1, the first displacement B1 of the inner ring of the first angular contact ball bearing 10 relative to the outer ring is measured under the action of the designed preload, and the second displacement B2 of the inner ring of the second angular contact ball bearing 20 relative to the outer ring is measured under the action of the designed preload, which also includes: placing the second angular contact ball bearing 20 with the opening facing upward on the corresponding tooling; aligning the needle of the lever micrometer to contact the inner ring of the second angular contact ball bearing 20, marking the position where the needle of the lever micrometer is aligned with the contact, and then clearing the lever micrometer; placing at least one counterweight 90 on the end face of the inner ring of the second angular contact ball bearing 20, recording the reading of the lever micrometer, and stopping loading until the loaded counterweight is greater than the designed preload. When the total mass of each counterweight 90 is equal to the designed preload, the reading of the lever micrometer is the second displacement B2.

[0053] In one example, the mass of a single balancing weight 90 is less than the allowable error value of the measured angular contact ball bearing preload design value, and the total mass of all balancing weights 90 is greater than 10% of the measured angular contact ball bearing preload design value.

[0054] Furthermore, the testing method of this embodiment also includes: measuring the actual preload force of the angular contact ball bearing assembly, measuring the first displacement B1 of the inner ring of the first angular contact ball bearing 10 relative to the outer ring under the actual preload force, and measuring the second displacement B2 of the inner ring of the second angular contact ball bearing 20 relative to the outer ring under the designed preload force.

[0055] Exemplarily, measuring the actual preload of the angular contact ball bearing assembly includes: assembling the angular contact ball bearing shaft assembly according to the actual installation method and placing it on the second tooling 80, and gradually loading the inner ring of the first angular contact ball bearing 10 in the angular contact ball bearing shaft assembly with counterweights 90. When the load increases to the resistance, the total weight of all loaded counterweights 90 is the actual preload of the angular contact ball bearing assembly.

[0056] refer to Figure 5 As shown, an embodiment of the present invention further provides an angular contact ball bearing preload force test accessory, namely a first tool 70, which includes: a first body 701, the first body 701 is a hollow cylindrical structure, the upper end surface of the first body 701 has a mounting portion 703, the mounting portion 703 is a stepped surface for supporting the outer ring of the angular contact ball bearing to be tested, and a plurality of test holes 702 are provided on the side wall of the first body 701.

[0057] refer to Figure 6 As shown, an embodiment of the present invention further provides an angular contact ball bearing preload test accessory, namely a second tooling 80, which includes: a second main body 804, the upper end of the second main body 804 has a first table 801, a second table 802 and a third table 803 from the outside to the inside, and the height of the first table 801 is smaller than the height of the second table 802, and the height of the second table 802 is smaller than the height of the third table 803.

[0058] The above test method is further illustrated below through a specific application. It can be seen from the measurement principle of the present invention that the measurement of the preload force of the angular contact ball bearing shaft system requires the measurement of A1, A2, B1, B2, and C in the above formula.

[0059] 1. Measurement of the thickness difference C between the inner spacer 30 and the outer spacer 40 .

[0060] First, use a micrometer or altimeter to measure the thickness of the inner spacer 30 and outer spacer 40, and then calculate their thickness difference, which is the thickness difference C. To ensure measurement accuracy, measure the thickness of the inner spacer 30 at four evenly distributed locations around the circumference of the inner spacer 30, and take the average of the four measurements as the thickness value of the inner spacer 30. Similarly, measure the thickness of the outer spacer 40 at four evenly distributed locations around the circumference of the outer spacer 40, and take the average of the four measurements as the thickness value of the outer spacer 40.

[0061] 2. Measurement of the height difference between the inner and outer rings of angular contact ball bearings.

[0062] 1) Place the first angular contact ball bearing 10 with its opening facing downward on the support 60 to support its inner ring, and then place the support 60 on the flat plate 50 (i.e., a grade 0 flat plate); 2) After the first angular contact ball bearing 10 is placed, place the lever micrometer on the flat plate 50, align the dial needle of the lever micrometer with the outer ring of the first angular contact ball bearing 10, and then reset the lever micrometer; 3) Push the lever micrometer so that the dial needle of the lever micrometer aligns with the inner ring of the first angular contact ball bearing 10. At this time, the reading of the lever micrometer is the height difference between the inner ring and the outer ring of the first angular contact ball bearing 10 at the current measuring point.

[0063] In order to ensure measurement accuracy, four evenly distributed measurement points can be taken around the circumference of the first angular contact ball bearing 10 to measure the height difference between the inner ring and the outer ring of the first angular contact ball bearing 10 respectively, and the average value of the four measurements is taken as the final height difference A1 between the inner ring and the outer ring of the first angular contact ball bearing 10.

[0064] The method for measuring the initial height difference A2 between the inner ring and the outer ring of the second angular contact ball bearing 20 may be the same as the method for measuring the height difference A1 , and will not be described in detail here.

[0065] 3. Measure the displacement of the inner ring of the angular contact ball bearing relative to the outer ring under the action of the designed preload force of the angular contact ball bearing shaft system.

[0066] 1) Fabricate the first fixture 70. The first fixture 70 is hollow and cylindrical, with a stepped surface (mounting portion 703) on the upper end that is higher on the outside and lower on the inside. Several test holes 702 are defined on the sidewall. In this embodiment, there are four test holes 702, evenly spaced along the same circumference. The stepped surface supports the outer ring of the angular contact ball bearing being tested and provides a clearance fit with the sidewall of the outer ring. The aperture of the test hole 702 should be such that the lever micrometer can pass through the test hole and align with the inner ring of the angular contact ball bearing to be tested; 2) Place the first angular contact ball bearing 10 (the angular contact ball bearing to be tested) with the opening facing upward on the tooling of step 1); 3) Align the needles of four lever micrometers with four positions on the inner ring of the first angular contact ball bearing 10 through the four test holes 702 respectively, and mark the position where the needle of each lever micrometer is aligned with the contact (to ensure the consistency of subsequent repeated test data), and then reset all lever micrometers; 4) Place multiple counterweights 90 one by one on the end face of the inner ring of the first angular contact ball bearing 10, and record the readings of the four lever micrometers during this process. Stop loading until the loaded counterweight is greater than the design preload. When the total mass of the counterweight 90 is equal to the design preload, the average of the four lever micrometer readings is the displacement B1 of the inner ring of the first angular contact ball bearing 10 relative to the outer ring under the action of the design preload.

[0067] Preferably, the mass of each counterweight 90 should be less than the allowable error value of the design value of the preload force of the angular contact ball bearing to be measured, the total mass of all counterweights 90 should be greater than 10% of the design value of the preload force of the angular contact ball bearing to be measured, and the counterweight 90 and the inner circle of the first angular contact ball bearing 10 should have matching stoppers, and there should also be matching stoppers between the counterweights 90 and the counterweights 90 to ensure that the force acts on the axis of the first angular contact ball bearing 10 to avoid the influence of offset loading on the measurement results.

[0068] The method for measuring the displacement B2 of the inner ring of the second angular contact ball bearing 20 relative to the outer ring under the designed preload is the same as the method for measuring the displacement B1 described above.

[0069] 4. When A1, A2, B1, B2, and C obtained from the above measurements meet the requirements of the above formula, it can be said that the shafting preload design meets the requirements and can be used in the product. Otherwise, it is an unqualified product and no further measurement is required.

[0070] 5. To avoid measurement errors and ensure data reliability, it is necessary to perform combined measurement of the angular contact ball shaft assembly. Figure 4 The combined measurement method is as follows: 1) making a second tool 80. The second tooling 80 is cylindrical as a whole, and its upper end is a table, which are recorded from the outside to the inside as the first table 801, the second table 802 and the third table 803. The height of the first table 801 is less than the height of the second table 802, and the height of the second table 802 is less than the height of the third table 803; 2) The angular contact ball bearing shaft system is assembled according to the actual installation method and placed on the second tooling 80, and the counterweight blocks 90 are loaded step by step on the inner ring of the first angular contact ball bearing 10 in the angular contact ball bearing shaft assembly. After each loading, the currently loaded counterweight block 90 is gently pushed along the tangential direction of the outer circle of the counterweight block 90 by hand. When the total mass of the loaded counterweight blocks 90 does not reach the designed preload, there is a gap between the inner ring of the first angular contact ball bearing 10 and the inner spacer 30, and the counterweight block 90 can be easily rotated at this time; when the load is loaded to the point where the hand obviously feels the increase in resistance, the total weight of all the loaded counterweight blocks 90 is the actual preload of this angular contact ball shaft assembly.

[0071] If the actual preload force measured in step 2) does not meet the design requirements, the difference between the actual preload force and the design preload force should be calculated, and the thickness difference C between the inner spacer 30 and the outer spacer 40 should be corrected with reference to the average displacement value. After correction, re-measurement should be carried out until the actual preload force measured meets the design requirements.

[0072] The basic concepts have been described above. It will be apparent to those skilled in the art that the above disclosures are merely illustrative and do not constitute limitations on this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and amendments to this application. Such modifications, improvements, and amendments are suggested in this application and remain within the spirit and scope of the exemplary embodiments of this application.

[0073] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0074] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions can be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the scope of the essential spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A method for testing the preload of an angular contact ball bearing, applied to an angular contact ball bearing assembly, wherein the angular contact ball bearing assembly comprises a first angular contact ball bearing, a second angular contact ball bearing, an inner spacer, and an outer spacer, wherein: include: Measuring the thickness of the inner spacer and the thickness of the outer spacer respectively, and then calculating the thickness difference C between the inner spacer and the outer spacer; measuring a first height difference A1 between the inner ring and the outer ring of the first angular contact ball bearing, and measuring a second height difference A2 between the inner ring and the outer ring of the second angular contact ball bearing; measuring a first displacement B1 of the inner ring of the first angular contact ball bearing relative to the outer ring under the action of the designed preload force, and measuring a second displacement B2 of the inner ring of the second angular contact ball bearing relative to the outer ring under the action of the designed preload force; Calculate whether the thickness difference C, the first height difference A1, the second height difference A2, the first displacement B1 and the second displacement B2 satisfy B1+B2=A1+A2+C, and thus determine whether the angular contact ball bearing assembly meets the requirements.

2. The angular contact ball bearing preload test method according to claim 1, wherein: The thickness difference C, the first height difference A1, the second height difference A2, the first displacement B1 and / or the second displacement B2 are measured using a micrometer or a height gauge.

3. The angular contact ball bearing preload test method according to claim 1, wherein: When measuring the thickness difference C, the first height difference A1, the second height difference A2, the first displacement B1 and / or the second displacement B2, a final measurement value is obtained by measuring multiple times and calculating an average value.

4. The angular contact ball bearing preload test method according to claim 1, wherein: The steps of measuring a first height difference A1 between the inner ring and the outer ring of the first angular contact ball bearing and measuring a second height difference A2 between the inner ring and the outer ring of the second angular contact ball bearing include: Place the first angular contact ball bearing with its opening downward on a support to support its inner ring, and place the support on a flat plate; Placing a lever dial indicator on the flat plate, aligning the dial needle of the lever dial indicator with the outer ring of the first angular contact ball bearing, and resetting the lever dial indicator to zero; Push the lever micrometer so that the needle of the lever micrometer is aligned and in contact with the inner ring of the first angular contact ball bearing. The current reading of the lever micrometer is the first height difference A1 between the inner ring and the outer ring of the first angular contact ball bearing at the measuring point.

5. The angular contact ball bearing preload test method according to claim 4, characterized in that: The steps of measuring a first height difference A1 between the inner ring and the outer ring of the first angular contact ball bearing and measuring a second height difference A2 between the inner ring and the outer ring of the second angular contact ball bearing further include: Place the second angular contact ball bearing with its opening downward on a support to support its inner ring, and place the support on a flat plate; Placing a lever dial indicator on the flat plate, aligning the dial needle of the lever dial indicator with the outer ring of the second angular contact ball bearing, and clearing the lever dial indicator to zero; Push the lever micrometer so that the needle of the lever micrometer is aligned and in contact with the inner ring of the second angular contact ball bearing. The current reading of the lever micrometer is the second height difference A2 between the inner ring and the outer ring of the second angular contact ball bearing at the measuring point.

6. The method for testing the preload force of an angular contact ball bearing according to claim 1, wherein: The steps of measuring a first displacement B1 of the inner ring of the first angular contact ball bearing relative to the outer ring under the action of the designed preload force, and measuring a second displacement B2 of the inner ring of the second angular contact ball bearing relative to the outer ring under the action of the designed preload force, include: Place the first angular contact ball bearing on the fixture with the opening facing upward; Aligning the needle of the lever dial indicator with the inner ring of the first angular contact ball bearing, marking the position where the needle of the lever dial indicator is aligned and in contact, and then clearing the lever dial indicator to zero; Place at least one counterweight on the inner ring end face of the first angular contact ball bearing, record the reading of the lever micrometer, and stop loading until the loaded counterweight is greater than the designed preload. When the total mass of all the counterweights is equal to the designed preload, the reading of the lever micrometer is the first displacement B1.

7. The method for testing the preload force of an angular contact ball bearing according to claim 6, wherein: The steps of measuring a first displacement B1 of the inner ring of the first angular contact ball bearing relative to the outer ring under the designed preload force, and measuring a second displacement B2 of the inner ring of the second angular contact ball bearing relative to the outer ring under the designed preload force, further include: Place the second angular contact ball bearing on the fixture with the opening facing upward; Aligning the needle of the lever dial indicator with the inner ring of the second angular contact ball bearing, marking the position where the needle of the lever dial indicator is aligned and in contact, and then clearing the lever dial indicator to zero; Place at least one counterweight on the inner ring end face of the second angular contact ball bearing, record the reading of the lever micrometer, and stop loading until the loaded counterweight is greater than the designed preload. When the total mass of all the counterweights is equal to the designed preload, the reading of the lever micrometer is the second displacement B2.

8. The method for testing the preload force of an angular contact ball bearing according to claim 6 or 7, wherein: The mass of a single counterweight is smaller than the allowable error value of the design value of the measured angular contact ball bearing preload, and the total mass of all the counterweights is greater than 10% of the design value of the measured angular contact ball bearing preload.

9. The method for testing the preload force of an angular contact ball bearing according to claim 1, wherein: It also includes: measuring the actual preload force of the angular contact ball bearing assembly, measuring the first displacement B1 of the inner ring of the first angular contact ball bearing relative to the outer ring under the actual preload force, and measuring the second displacement B2 of the inner ring of the second angular contact ball bearing relative to the outer ring under the designed preload force.

10. The method for testing the preload force of an angular contact ball bearing according to claim 9, wherein: Measuring the actual preload force of the angular contact ball bearing assembly includes: After assembling the angular contact ball bearing shaft assembly according to the actual installation method, place it on the tooling, and load counterweights step by step onto the inner ring of the first angular contact ball bearing in the angular contact ball bearing shaft assembly. When the load increases to the resistance, the total weight of all loaded counterweights is the actual preload force of the angular contact ball bearing assembly.

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