Angular contact ball bearing pre-tightening force testing method and fitting

Abstract

The invention provides an angular contact ball bearing pre-tightening force testing method and an accessory, and the testing method comprises the steps: respectively measuring the thickness of an inner space ring and the thickness of an outer space ring, and then calculating the thickness difference C between the inner space ring and the outer space ring; measuring a first height difference A1 between an inner ring and an outer ring of the first angular contact ball bearing, and measuring a second height difference A2 between an inner ring and an 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 the designed pre-tightening 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 pre-tightening force; and calculating whether the thickness difference C, the first height difference A1, the second height difference A2, the first displacement B1 and the first displacement B1 meet B1 + B2 = A1 + A2 + C or not so as to know whether the angular contact ball bearing assembly meets the requirement or not. The method is simple in test, convenient to operate and high in test precision.

Description

Technical Field

[0001] The invention mainly relates to the technical field of bearings, and in particular to a preload force testing method and accessories for 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 the key design parameter of the rotating mechanism axis 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 axis 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 space high-precision tracking turntable, designers will calculate the precise angular contact ball bearing preload based on actual working conditions such as operating speed, working load, and use 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 the purchased angular contact ball bearings so as to find products that do not meet the design requirements as early as possible. At present, the angular contact ball bearings used in engineering are all unpaired bearings. Before use, a simple estimate of the preload of the angular contact ball bearings is required based on the accuracy of the shaft system of the rotating mechanism and the friction force. 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. In the process of testing the preload of the angular contact ball bearing, these two estimation methods require repeated disassembly and assembly of related parts such as bearings or sleeves for clearance adjustment, which 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 testing accuracy.

[0006] To solve the above technical problems, in a first aspect, the present invention 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, a second angular contact ball bearing, an inner spacer and an outer spacer, and 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 of the inner ring of the first angular contact ball bearing 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 relative to the outer ring under the action of a 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 first displacement B1 satisfy B. 1 +B 2 =A 1 +A 2 +C, and then know 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 first 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 first displacement B1, 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 also 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 its 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 to 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 when the loaded counterweight is greater than the designed preload; when the total mass of each of the counterweights 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 its opening facing upward on a 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 to 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 when the loaded counterweight is greater than the designed preload; when the total mass of each of the counterweights 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 block is smaller than the allowable error value of the design value of the measured angular contact ball bearing preload force, and the total mass of all the counterweight blocks is greater than 10% of the design value of the measured angular contact ball bearing preload force.

[0014] Optionally, it also includes: measuring the actual preload force of the angular contact ball bearing assembly, measuring a 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 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.

[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 a 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 the 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 is a hollow cylindrical structure, the upper end face of the first main body has a placement portion, the placement portion is a step surface for supporting the outer ring of the angular contact ball bearing to be tested, and a plurality of test holes are 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 between the inner ring and the outer ring of the first angular contact ball bearing is measured, and the second height difference A2 between the inner ring and the outer ring of the second angular contact ball bearing is measured; and 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; 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; and finally, 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. 1 +B 2 =A 1 +A 2 +C, and then know whether the angular contact ball bearing assembly meets the requirements. It 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 included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present application. In the accompanying drawings:

[0020] Figure 1 is a schematic diagram of the installation of an angular contact ball shaft assembly in one embodiment of the present invention;

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

[0024] Figure 5 It is a structural schematic 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 figure:

[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-plate;

[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] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0037] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present 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, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0038] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0039] Flowcharts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, various steps may be processed in reverse order or simultaneously. At the same time, 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 shaft assembly and support 60 used 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 a support 60. The preload method adopted by the first angular contact bearing 10 and the second angular contact ball bearing 20 is positioning preload, and the inner spacer 30 and the outer spacer 40 are arranged between the first angular contact ball bearing 10 and the second angular contact ball bearing 20. The upper end surface of the support 60 has a circular ring protrusion, which is used to support 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 ring 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 raceways of the first angular contact ball bearing 10, causing the steel balls and the raceways to generate an interaction force, i.e., a preload, until the gap α is reduced to 0, i.e., after the inner spacer ring 30 and the inner ring of the first angular contact ball bearing 10 are in contact with each other, the force F continues to increase, causing the inner ring of the first angular contact ball bearing 10 and the inner spacer ring 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 ring 30, the preload force of the angular contact ball shaft assembly tends to be stable.

[0042] From the principle of generating the preload of the angular contact ball shaft assembly, it can be seen that the initial gap between the inner ring of the first angular contact ball bearing 10 and the inner spacer 30 determines the preload of the angular contact ball shaft assembly. The initial gap includes 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 thickness difference C between the inner spacer 30 and the outer spacer 40. The size of the initial gap 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 action of the designed preload, that is, B 1 +B 2 =A 1 +A 2 +C. It should be noted that the actual calculation may not be completely accurate to B 1 +B 2 =A 1 +A 2 +C, there is a certain error, but as long as the error is within the acceptable range, it is considered to meet B 1 +B 2 =A 1 +A 2 +C.

[0043] It can be seen from the above formula that by measuring the thickness difference C between the inner spacer ring 30 and the outer spacer ring 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 design preload, and the displacement B2 of the inner ring of the second angular contact ball bearing 20 relative to the outer ring, it can be checked whether the preload force of the angular contact ball shaft assembly meets the design requirements.

[0044] Therefore, the present 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, and 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 a 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 first displacement B1 satisfy B. 1 +B 2 =A 1 +A 2 +C, and then know 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 height difference C, the first height difference A1, the second height difference A2, the first displacement B1 and / or the first displacement B2.

[0046] The micrometer consists of a fixed sleeve and a rotatable micrometer screw, on which a spiral line is engraved. For each turn, the distance moved by the screw is fixed, usually 0.5 mm or 1 mm. When using a micrometer, it is necessary to calibrate the zero point first, then measure the size of the workpiece, read the scale on the fixed sleeve and the scale on the micrometer screw to obtain accurate measurement results. The altimeter is mainly based on laser ranging technology, that is, a laser beam is emitted to the target object, and the time of the laser echo is measured to calculate the distance. The altimeter generates a laser beam through a built-in laser generator, which irradiates the target object and is received by the receiver after being reflected by the target. After receiving the laser, the receiver will send a signal back to the radar system, and calculate the position of the target point in the time from the emission of the laser to the reception of the signal, thereby measuring the vertical distance between the target object and the altimeter. In this embodiment, the use of a micrometer or an altimeter can meet the test requirements of the angular contact ball bearing assembly.

[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 first displacement B2, a final measurement value is obtained by measuring multiple times and calculating an average value.

[0048] In experiments or measurements, errors may be caused by a variety of random factors, and the effects of these factors may be different in different measurements. When multiple measurements are taken and the average is calculated, these random errors tend to appear in different ways in different measurements, thereby offsetting each other in the averaging process, making the average closer to the true value. Exemplarily, when measuring the thickness difference C, in order to ensure the measurement accuracy, four evenly distributed positions are taken in the circumference of the inner spacer 30 to measure the thickness of the inner spacer 30, and the average of the four measurements is taken as the thickness value of the inner spacer 30; similarly, four evenly distributed positions are taken in the circumference of the outer spacer 40 to measure the thickness 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 one 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 dial 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; pushing the lever micrometer so that the dial 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 step of measuring the second height difference A2 between the inner ring and the outer ring of the second angular contact ball bearing 20 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 plate 50; placing the lever micrometer on the 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 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, including: placing the first angular contact ball bearing 10 with its 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 to 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 when the loaded counterweight is greater than the designed preload, and when the total mass of each counterweight 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, and the step also includes: placing the second angular contact ball bearing 20 with its 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 to 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 when the loaded counterweight is greater than the designed preload, and 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 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 second tooling 80, and gradually loading counterweights 90 onto the inner ring of the first angular contact ball bearing 10 in the angular contact ball bearing shaft assembly. When the load increases to the point where the resistance increases, the total weight of all the loaded counterweights 90 is the actual preload force 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 placement portion 703, the placement portion 703 is a step 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 top 801, a second table top 802 and a third table top 803 from the outside to the inside, and the height of the first table top 801 is less than the height of the second table top 802, and the height of the second table top 802 is less than the height of the third table top 803.

[0058] The above test method is further described 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 a height gauge to measure the thickness of the inner spacer 30 and the outer spacer 40 respectively, and then calculate their thickness difference, that is, the thickness difference C; in order to ensure the measurement accuracy, four evenly distributed positions are taken in the circumference of the inner spacer 30 to measure the thickness of the inner spacer 30, and the average value of the four measurements is taken as the thickness value of the inner spacer 30. Similarly, four evenly distributed positions are taken in the circumference of the outer spacer 40 to measure the thickness of the outer spacer 40, and the average value of the four measurements is taken as the thickness value of the outer spacer 40.

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

[0062] 1) Place the first angular contact ball bearing 10 with its opening downward on the support 60 to support its inner ring, and then place the support 60 on the flat plate 50 (i.e., the level 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 to zero; 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] To ensure measurement accuracy, four evenly distributed measurement points can be selected 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, 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 herein.

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

[0066] 1) Make a first tool 70, which is in the shape of a hollow cylinder, and the upper end surface is a stepped surface (piece placement portion 703) with a high outer surface and a low inner surface, and a plurality of test holes 702 are opened on the side wall. In this embodiment, there are four test holes 702, which are evenly distributed along the same circumference. The stepped surface is used to support the outer ring of the angular contact ball bearing to be tested, and has a clearance fit with the side wall of the outer ring of the angular contact ball bearing to be tested. 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 its opening facing upward on the tooling of step 1); 3) Through the four test holes 702, align the needles of the four lever micrometers with four positions on the inner ring of the first angular contact ball bearing 10, respectively, and mark the position where the needle of each lever micrometer aligns with the contact (to ensure the consistency of the subsequent repeated test data), and then reset all the lever micrometers; 4) Place multiple counterweights 90 one by one on the inner ring end face of the first angular contact ball bearing 10, and record the readings of the four lever micrometers in this process, until the loading is stopped when the loaded counterweight is greater than the designed preload. When the total mass of the counterweight 90 is equal to the designed preload, the average value 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 designed 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 counterweights 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.

[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 shaft preload design meets the requirements and can be used in the product. Otherwise, it is a defective product and no subsequent 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 fixture 80 is cylindrical as a whole, and its upper end is a table, which is recorded as the first table 801, the second table 802 and the third table 803 from the outside to the inside. 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) After the angular contact ball bearing shaft system is assembled according to the actual installation method, it is placed on the second fixture 80, and the counterweight block 90 is 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 tangent direction of the outer circle of the counterweight block 90 by hand. When the total mass of the loaded counterweight block 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 ring 30 and the outer spacer ring 40 should be corrected with reference to the average displacement value. After correction, the test should be repeated until the actual preload force measured meets the design requirements.

[0072] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0073] In some embodiments, numbers describing the number of components and attributes are used. 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 specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification 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 setting of such numerical values ​​is 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 may 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 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, characterized in that: include: Respectively measuring the thickness of the inner spacer and the thickness of the outer spacer, 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; Under the action of the designed preload force, a 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, a second displacement B2 of the inner ring of the second angular contact ball bearing relative to the outer ring is measured; The thickness difference C, the first height difference A1, the second height difference A2, the first displacement B1 and whether the first displacement B1 satisfies B1+B2=A1+A2+C are calculated, thereby determining whether the angular contact ball bearing assembly meets the requirements.

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

3. The angular contact ball bearing preload test method according to claim 1, characterized in that: When measuring the thickness difference C, the first height difference A1, the second height difference A2, the first displacement B1 and / or the first 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, 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 include: Place the first angular contact ball bearing opening downward on a support to support its inner ring, and place the support on a flat plate; Placing a lever micrometer on the flat plate, aligning the needle of the lever micrometer with the outer ring of the first angular contact ball bearing, and clearing the lever micrometer to zero; The lever micrometer is pushed 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 method for testing the preload force of an angular contact ball bearing 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: placing the second angular contact ball bearing 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, aligning the needle of the lever micrometer with the outer ring of the second angular contact ball bearing, and clearing the lever micrometer to zero; The lever micrometer is pushed 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 angular contact ball bearing preload test method according to claim 1, characterized in that: 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 include: placing the first angular contact ball bearing with the opening facing upward on the tooling; Align the needle of the lever micrometer to contact the inner ring of the first angular contact ball bearing, mark the position where the needle of the lever micrometer is aligned and in contact, and then reset the lever micrometer to zero; Place at least one counterweight block 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 block is greater than the designed preload. When the total mass of all the counterweight blocks 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, characterized in that: 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: placing the second angular contact ball bearing with the opening facing upward on the tooling; Align the needle of the lever micrometer to contact the inner ring of the second angular contact ball bearing, mark the position where the needle of the lever micrometer is aligned and in contact, and then reset the lever micrometer 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, characterized in that: The mass of a single counterweight block is smaller than the allowable error value of the design value of the measured angular contact ball bearing preload force, and the total mass of all the counterweight blocks is greater than 10% of the design value of the measured angular contact ball bearing preload force.

9. The method for testing the preload force of an angular contact ball bearing according to claim 1, characterized in that: It also includes: measuring the actual preload force of the angular contact ball bearing assembly, measuring a 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 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.

10. The method for testing the preload force of an angular contact ball bearing according to claim 9, characterized in that: Measuring the actual preload force of the angular contact ball bearing assembly includes: After the angular contact ball bearing shaft assembly is assembled according to the actual installation method, it is placed on the tooling, and counterweights are loaded 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 the loaded counterweights is the actual preload force of the angular contact ball bearing assembly.

11. An angular contact ball bearing preload test accessory, characterized in that: include: The first body is a hollow cylindrical structure, the upper end surface of the first body has a mounting portion, the mounting portion is a step surface for supporting the outer ring of the angular contact ball bearing to be measured, and a plurality of test holes are arranged on the side wall of the first body.

12. An angular contact ball bearing preload test accessory, characterized in that: include: The second body has a first table top, a second table top and a third table top at its upper end from outside to inside, and the height of the first table top is smaller than the height of the second table top, and the height of the second table top is smaller than the height of the third table top.

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