Aeroflight precision bearing assembly pre-tightening force measuring device and method

Abstract

The application relates to an aviation precise bearing assembly pre-tightening force measuring device and method, and belongs to the technical field of optical machine adjustment and setting. The device comprises a fixed base, an adapter disc, a pressure conducting element, a pressure cylinder, a pressure sensor, a pressure ring tool and a torque wrench. The upper bearing is coaxially sleeved on a bearing mounting position of a rotary inner shaft. The bearing inner pressure ring is threadedly connected with the rotary inner shaft and is pressed on the upper bearing inner ring. The rotary inner shaft is coaxially fixed on the fixed base through the adapter disc. The pressure sensor is installed on the fixed base. The pressure conducting element is installed on the pressure sensor. The pressure cylinder is used for transferring the pressure applied to the upper bearing inner ring by the pressure ring tool through the bearing inner pressure ring to the pressure conducting element, and then to the pressure sensor, and the pressure digital display table is used for displaying the pressure. The application realizes bearing pre-tightening force measurement and corresponding tightening torque determination of each set of products, ensures that the bearing assembly pre-tightening forces of each product shaft in the shaft system of the same product are consistent, and improves the stability of product quality.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of optical mechanical adjustment, and particularly relates to an aviation precision bearing assembly pre-tightening force measuring device and method, which is used for accurate measurement of aviation precision paired angular contact bearing assembly pre-tightening force, guarantees the consistency of product bearing pre-tightening force, and further ensures the stability of product quality. BACKGROUND

[0002] In an aviation optical mechanical product, in order to obtain a large enough exploration field, a far enough detection distance and a high enough exploration precision, a precision rotary shaft system is often used, and the rotary precision and the rotary friction torque of the shaft system have very high requirements. The rotary precision and the rotary friction torque of the shaft system are directly affected by bearing assembly pre-tightening force. The pre-tightening force adjustment of the aviation precision paired angular contact bearing assembly generally adopts a pre-tightening mode of a pressing ring matched with a screw thread, such as setting an external screw thread on a rotary inner shaft and matching the external screw thread with an internal screw thread in a bearing inner pressing ring, and indirectly adjusting the bearing pre-tightening force by adjusting the tightening torque applied to the pressing ring. In the actual product assembly process, in order to guarantee the consistency of the bearing pre-tightening force, a torque wrench is used to apply the same tightening torque to the bearing installed on each product, so as to expect to ensure that the bearing pre-tightening force is the same. However, due to the differences in sizes and surface qualities of different parts, even if the same tightening torque is used, the rotary precision and the rotary friction torque of the shaft system of different products still show significant differences.

[0003] In order to improve the stability of product quality, it is necessary to guarantee the consistency of the bearing assembly pre-tightening force installed on the shaft system of the same product. When the bearing pre-tightening torque is controlled by the torque wrench, it is obviously impossible to guarantee that the pre-tightening force of the bearing of the shaft system of the same product is the same, and therefore, it is necessary to measure the tightening torque corresponding to the required pre-tightening force of the bearing on each product. SUMMARY

[0004] Technical problems to be solved:

[0005] In order to avoid the shortcomings of the prior art, the application provides an aviation precision bearing assembly pre-tightening force measuring device and a measuring method. When the bearing inner pressing ring is used to pre-tighten the upper bearing inner ring installed on the rotary inner shaft, the device can measure the pre-tightening force of the bearing installed on each product under different tightening torque pre-tightening, and further obtain the tightening torque of the bearing when the required pre-tightening force is reached, so as to effectively guarantee the stability of the assembly quality of the shaft system of the same product.

[0006] The technical scheme of the present application is: an aviation precision bearing assembly pre-tightening force measuring device, comprising a fixed base 9, an adapter disc 7, a pressure conducting element 8, a pressure cylinder 13, a pressure sensor 10, a pressure ring tool 14 and a torque wrench 15, the fixed base 9 is located at the bottom of the measuring device, the upper surface is coaxial with the center and provided with a ring-shaped boss, and a plurality of radial notches are uniformly distributed in the circumferential direction of the ring-shaped boss; the pressure sensor 10 is installed at the center of the fixed base 9; the adapter disc 7 is coaxially installed on the ring-shaped boss, the upper surface thereof is coaxially connected with the bottom surface of the rotary inner shaft 1; the upper bearing 5 is installed on the bearing installation position of the rotary inner shaft 1, the bearing inner pressure ring 3 is threadedly connected with the rotary inner shaft 1 and pressed on the bearing inner ring of the upper bearing 5; the pressure conducting element 8 is a claw-shaped support disc, the bottom thereof is installed on the pressure sensor 10, and the claw part extends out of the notch of the ring-shaped boss; the pressure cylinder 13 is coaxially installed on the upper part of the pressure conducting element 8, the upper surface of the pressure cylinder 13 is in contact with the lower surface of the bearing outer ring of the upper bearing 5; the pressure ring tool 14 is a circular barrel-shaped structure with an open bottom, the bottom is matched and clamped with the bearing inner pressure ring 3, and a torque wrench fixing groove is arranged at the center of the top; the torque wrench 15 is matched with the torque wrench fixing groove and used for applying torque; the torque applied by the torque wrench 15 is transmitted to the bearing inner pressure ring 3 through the pressure ring tool 14, the bearing inner pressure ring 3 applies pressure to the inner ring of the upper bearing 5, the pressure is further transmitted to the bearing outer ring through the ball, and finally applied to the pressure cylinder 13 and transmitted to the pressure sensor 10 through the pressure conducting element 8.

[0007] Further technical scheme of the present application is: the pressure sensor 10 is connected with a pressure digital display 12, which is used for displaying the pressure value measured by the pressure sensor in real time.

[0008] Further technical scheme of the present application is: the adapter disc 7 is a flange structure with coaxial ring-shaped steps on the upper and lower surfaces, the lower surface step is coaxially matched with the ring-shaped boss of the fixed base 9, and the upper surface step is coaxially matched with the inner diameter and bottom surface of the rotary inner shaft 1, and the rotary inner shaft 1, the adapter disc 7 and the fixed base 9 are coaxially connected through screws 11.

[0009] Further technical scheme of the present application is: the pressure conducting element 8 is a three-claw structure with an included angle of 120°, the upper surfaces of the three claws are in the same plane, and the edges of the three claws are coaxially provided with circular arc steps, which are used for ensuring that the pressure cylinder 13 and the pressure conducting element 8 are coaxial and radially limited; the bottom center of the pressure conducting element 8 is provided with a mounting groove, and the top of the pressure sensor 10 is fixed in the mounting groove through the screw 11.

[0010] Further technical scheme of the present application is: the pressure cylinder 13 is a cylinder, and the upper and lower end faces have parallelism and flatness requirements, and the pressure cylinder 13 transmits the pre-tightening force of the bearing in the assembled state to the pressure conducting element 8.

[0011] The further technical scheme of the present application is that a first groove is arranged at the center of the upper surface of the fixed base 9, and the pressure sensor 10 is installed in the first groove.

[0012] The further technical scheme of the present application is that the number of notches on the annular boss of the fixed base 9 corresponds to the number of claws of the pressure conductor 8, and the fixed base 9 is fixed on the workbench by the screw 11.

[0013] The further technical scheme of the present application is that a group of bosses are uniformly distributed on the annular end surface of the bottom of the pressing ring tool 14, and are matched and clamped with a group of second grooves uniformly distributed on the inner pressing ring 3 of the bearing.

[0014] The further technical scheme of the present application is that the torque wrench 15 is a commercial adjustable torque wrench, the pressure sensor 10 is a commercial precision pressure sensor, and the pressure digital display meter 12 is a commercial pressure digital display meter, and the pressure digital display meter 12 is used in cooperation with the pressure sensor 10.

[0015] The further technical scheme of the present application is a method for measuring the pre-tightening force of an aviation precision bearing assembly, and the steps are as follows:

[0016] Step one, install the pressure sensor 10 in the first groove of the fixed base 9 by the screw 11, and then fix the fixed base 9 on the workbench surface by the screw 11;

[0017] Step two, connect the pressure sensor 10 with the pressure digital display meter 12, connect the power supply, and the pressure digital display meter 12 displays the pressure value;

[0018] Step three, assemble the bottom installation groove of the pressure conductor 8 with the pressure sensor 10, and fix them by the screw 11;

[0019] Step four, assemble the bottom surface of the rotary inner shaft 1 with the upper surface step of the adapter disc 7, and fix them by the screw 11; assemble the lower surface step of the adapter disc 7 with the inner ring of the annular boss of the fixed base 9, and fix them by the screw 11;

[0020] Step five, place the pressing cylinder 13 on the pressure conductor 8, and cooperate with the circular arc step at the edge of the pressure conductor 8 to ensure that the pressing cylinder 13 is coaxial with the pressure conductor 8;

[0021] Step six, assemble the upper side bearing 5 in a back-to-back manner on the rotary inner shaft 1, and the lower surface of the bearing outer ring of the upper side bearing 5 is in contact with the upper surface of the pressing cylinder 13, and the change of the value displayed by the pressure sensor 10 is used as the criterion;

[0022] Step seven, coaxially assemble the inner pressing ring 3 of the bearing on the rotary inner shaft 1, gradually tighten the inner pressing ring 3 of the bearing by using the pressing ring tool 14, so that the gap between the inner pressing ring 3 of the bearing and the upper side bearing 5 is almost zero, and the value of the pressure digital display meter 12 is reset to zero.

[0023] Step eight, install the torque wrench 15 to the compression ring tool 14, use the predetermined tightening torque to apply torque, stop applying torque when the torque wrench 15 slips; observe the pressure digital display 12, record the pressure value after the value is stable; the recorded pressure value is the axial pretightening force of the bearing applied by the set torque; the axial pretightening force of the bearing is expressed as: bearing axial pretightening force = bearing inner compression ring axial pressure - friction force between the inner wall of the bearing inner ring and the outer wall of the rotary inner shaft;

[0024] Step nine, adjust the tightening torque, record the corresponding tightening torque after the bearing pretightening force meeting the use requirement is obtained; the tightening torque can ensure the consistency of the bearing pretightening force in each product of the same product shafting during formal assembly.

[0025] Beneficial effects

[0026] The beneficial effects of the present application are that the aviation precision bearing assembly pretightening force measuring device and method of the present application coaxially sleeves the upper bearing on the bearing mounting position of the rotary inner shaft, threadedly connects the bearing inner compression ring with the rotary inner shaft and compresses the bearing inner compression ring on the bearing inner ring of the upper bearing, coaxially fixes the rotary inner shaft on the fixed base through the adapter disc, installs the pressure sensor on the fixed base, installs the pressure conducting element on the pressure sensor, transmits the pressure applied to the upper bearing inner ring by the bearing inner compression ring through the compression ring tool to the pressure conducting element by the pressure cylinder, further transmits the pressure to the pressure sensor, and displays the pressure on the pressure digital display, realizes the bearing pretightening force measurement of each set of products and the corresponding tightening torque determination, and ensures the stability of the assembly quality of the same product shafting.

[0027] The present application ensures the coaxial installation of the rotary inner shaft and the fixed base through the coaxial annular steps arranged on the upper and lower surfaces of the rotary inner shaft, and ensures the stability and accuracy of the measurement.

[0028] The present application realizes the effective transmission of the pressure by extending the claw part of the pressure conducting element from the slot of the annular boss of the fixed base and coaxially installing the pressure cylinder on the pressure conducting element, that is, the pressure applied to the upper bearing inner ring is transmitted to the upper bearing outer ring through the ball, and then applied to the pressure cylinder, and then transmitted to the pressure sensor through the pressure conducting element, and displayed on the pressure digital display.

[0029] The method of the application uses the measuring device, first applies a preset torque through the torque wrench, and observes the indication of the pressure digital display meter, at this time, the indication of the pressure digital display meter is the axial pre-tightening force applied to the bearing by the set torque, if the pre-tightening force is not the required pre-tightening force, the torque of the torque wrench can be adjusted by loosening the inner pressure ring of the bearing, until the pressure digital display meter displays the required pre-tightening force, that is, the tightening torque required to achieve the pre-tightening force is obtained, and then the tightening torque is used to complete the real assembly.

[0030] The application is aimed at the shaft system of the angular contact aviation precision bearing assembled in a pair of back-to-back mode, when the inner pressure ring of the bearing is used to pre-tighten the inner ring of the bearing mounted on the rotary inner shaft, the device can measure the pre-tightening force of the bearing in each product of the same product shaft system under different tightening torque pre-tightening, and then obtain the tightening torque of the bearing when the pre-tightening force reaches the required pre-tightening force, so as to effectively ensure the stability of the assembly quality of the same product shaft system in actual installation.

[0031] The application has simple structure and convenient operation, and ensures that the pre-tightening force of each product bearing in the same product shaft system is consistent, and the stability of the product quality is improved. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is a schematic diagram for actual installation of the pair of angular contact bearings;

[0033] Figure 2 It is a schematic diagram of the aviation precision bearing assembly pre-tightening force measuring device of the application;

[0034] Figure 3 It is a schematic diagram of the pressure conducting element;

[0035] Figure 4 It is a real object diagram of the application;

[0036] BRIEF DESCRIPTION OF DRAWINGS 1. Rotary inner shaft 2. Rotary outer shaft 3. Bearing inner pressure ring 4. Bearing outer pressure ring 5. Upper bearing 6. Lower bearing 7. Adapter disc 8. Pressure conducting element 9. Fixed base 10. Pressure sensor 11. Screw 12. Pressure digital display meter 13. Pressure cylinder 14. Pressure ring tooling 15. Torque wrench. DETAILED DESCRIPTION

[0037] The embodiments described below with reference to the drawings are exemplary and are intended to explain the application, and cannot be understood as a limitation of the application.

[0038] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0039] Referring to Figures 1-4 The present application is an aviation precision bearing assembly pre-tightening force measuring device, comprising a fixed base 9, an adapter disc 7, a pressure conducting element 8, a pressure cylinder 13, a pressure sensor 10, a pressure ring tool 14 and a torque wrench 15. The fixed base 9 is located at the bottom of the measuring device, and a first groove is provided on the upper surface and at the center position. A screw hole is provided in the first groove for installing the pressure sensor 10. A ring-shaped boss is coaxially provided on the upper surface and at the center position. Three radial notches are uniformly distributed around the ring-shaped boss. A stepped surface is provided on the outer edge of the fixed base 9, and a set of threaded holes are uniformly distributed on the stepped surface for installing the fixed base 9 on the workbench by screws. The pressure sensor 10 is installed in the first groove by screws. The pressure sensor 10 is connected with a pressure digital display 12 for real-time display of the pressure value measured by the pressure sensor 10.

[0040] The adapter disc 7 is coaxially installed on the ring-shaped boss of the fixed base 9. The adapter disc 7 has a flange structure with coaxial ring-shaped steps on the upper and lower surfaces. The lower surface step is coaxially matched with the ring-shaped boss of the fixed base 9, and the upper surface step is coaxially matched with the inner diameter and bottom surface of the rotary inner shaft 1. The rotary inner shaft 1, the adapter disc 7 and the fixed base 9 are coaxially connected by screws 11. The upper side bearing 5 is pressed onto the bearing installation position of the rotary inner shaft 1. The bearing inner ring 3 is threadedly connected with the rotary inner shaft 1 and pressed onto the bearing inner ring of the upper side bearing 5.

[0041] The pressure conducting element 8 is a claw-shaped support disc with three claws at an included angle of 120°. The upper surfaces of the three claws are in the same plane and meet the flatness requirement. The edges of the three claws are coaxially provided with a circular arc step at the center. The circular arc step requires high precision to ensure the coaxiality and radial positioning of the pressure cylinder 13 and the pressure conducting element 8. An installation groove is provided at the center position of the bottom of the pressure conducting element 8. A screw hole is provided in the installation groove. The top of the pressure sensor 10 is fixed in the installation groove by screws 11. The claw part of the pressure conducting element 8 extends out of the notch of the ring-shaped boss of the fixed base 9.

[0042] The pressure cylinder 13 is a cylinder, and the upper and lower end faces have parallelism and flatness requirements; the pressure cylinder 13 is coaxially installed on the three claws of the pressure guide 8, the outer diameter bottom of the pressure cylinder 13 is in contact with the arc stepped surface of the pressure guide 8, the upper surface of the pressure cylinder 13 is in contact with the lower surface of the outer ring of the upper bearing 5, and the pressure cylinder 13 transmits the pre-tightening force of the bearing in the assembled state to the pressure guide 8.

[0043] The pressure ring tool 14 is a circular barrel structure with an open bottom, and a set of convex bosses are uniformly distributed on the annular end face of the bottom and are in clamping and matching connection with a set of second grooves uniformly distributed on the bearing inner pressure ring 3; a torque wrench fixing groove is arranged at the center position of the top; the torque wrench 15 is matched with the torque wrench fixing groove; and the pressure ring tool 14 is used for accurately transmitting the torque applied by the torque wrench 15 to the bearing inner pressure ring 3.

[0044] The torque wrench 15 in the application is a commercial adjustable torque wrench, which can apply different torques to the pressure ring tool 14; the pressure sensor 10 is a commercial precision pressure sensor, which is used for accurately measuring the pressure transmitted by the pressure guide 8; the pressure digital display meter 12 is a commercial pressure digital display meter, and the pressure digital display meter 12 is used in cooperation with the pressure sensor 10; the torque applied by the torque wrench 15 to the bearing inner pressure ring 3 through the pressure ring tool 14, the bearing inner pressure ring 3 applies pressure to the inner ring of the upper bearing 5, and then the pressure is transmitted to the outer ring of the bearing through the ball, and finally the pressure is applied to the pressure cylinder 13 and transmitted to the pressure sensor 10 through the pressure guide 8.

[0045] The method for measuring the pre-tightening force of the aviation precision bearing assembly by the device is as follows:

[0046] Step one, install the pressure sensor 10 in the first groove of the fixed base 9 through the screw 11, and then fix the fixed base 9 on the workbench top through the screw 11;

[0047] Step two, connect the pressure sensor 10 with the pressure digital display meter 12, connect the power supply, and the pressure digital display meter 12 displays the pressure value;

[0048] Step three, assemble the bottom installation groove of the pressure guide 8 with the pressure sensor 10, and fix them through the screw 11;

[0049] Step four, assemble the bottom surface of the rotary inner shaft 1 with the upper surface step of the adapter disc 7, and fix them through the screw 11; assemble the lower surface step of the adapter disc 7 with the annular boss inner ring of the fixed base 9, and fix them through the screw 11;

[0050] Step five, place the pressure cylinder 13 on the pressure guide 8, and match it with the arc stepped surface at the edge of the pressure guide 8, so as to ensure that the pressure cylinder 13 is coaxial with the pressure guide 8;

[0051] Step six, the upper bearing 5 needs to be assembled in pairs in a back-to-back manner, and the lower surface of the bearing outer ring of the upper bearing 5 is in contact with the upper surface of the pressure cylinder 13, so that the value of the pressure sensor 10 appears to change;

[0052] Step seven, the bearing inner pressure ring 3 is coaxially sleeved on the rotating inner shaft 1, the bearing inner pressure ring 3 is gradually tightened by using the pressure ring tool 14, so that the gap between the bearing inner pressure ring 3 and the upper bearing 5 is almost zero, and the value of the pressure digital display table 12 is cleared.

[0053] Step eight, the torque wrench 15 is installed on the pressure ring tool 14, a predetermined tightening torque is applied, and the torque is stopped as soon as the torque wrench 15 slips; the pressure value is recorded after the value of the pressure digital display table 12 is stable; the recorded pressure value is the axial pretightening force applied to the bearing by the set torque; the axial pretightening force of the bearing is expressed as: bearing axial pretightening force = bearing inner pressure ring axial pressure - friction between the inner wall of the bearing inner ring and the outer wall of the rotating inner shaft.

[0054] Step nine, adjust the tightening torque, and record the corresponding tightening torque after the bearing pretightening force meeting the use requirements is obtained; the tightening torque can ensure that the bearing pretightening force of each product in the shafting of the same product is consistent during formal assembly.

[0055] The method sets the torque value of the torque wrench 15, transmits the torque to the bearing inner pressure ring 3 by rotating the torque wrench 15 and the pressure ring tool 14, applies pressure to the bearing inner ring of the upper bearing 5 by the bearing inner pressure ring 3, transmits the pressure to the bearing outer ring of the upper bearing 5 by the ball, finally applies the pressure to the pressure cylinder 13, and transmits the pressure to the pressure sensor 10 through the pressure conducting element 8, and displays the corresponding pressure value on the pressure digital display table 12. The pressure value is the axial pretightening force applied to the bearing by the set torque. When the pretightening force is not in the required range, the bearing inner pressure ring 3 is loosened, the torque of the torque wrench 15 is adjusted again, and the corresponding tightening torque is recorded when the pressure digital display table 12 displays the required pretightening force range. The tightening torque is the tightening torque for bearing pretightening in the real assembly of the product. After the measurement is completed, the rotating inner shaft 1, the bearing inner pressure ring 3 and the upper bearing 5 are removed and placed back in the real assembly environment, and the final measured tightening torque corresponding to the required pretightening force is used for bearing pretightening, so as to ensure that the pretightening force of each set of product bearings is consistent.

[0056] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and cannot be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments without departing from the principles and purposes of the present application within the scope of the present application.

Claims

1. A device for measuring the preload force of a precision aerospace bearing assembly, characterized in that: The device includes a fixed base (9), a connecting plate (7), a pressure transmitting component (8), a pressure cylinder (13), a pressure sensor (10), a pressure ring fixture (14), and a torque wrench (15). The fixed base (9) is located at the bottom of the measuring device, and its upper surface is coaxially provided with an annular boss. Multiple radial slots are evenly distributed around the annular boss. The pressure sensor (10) is installed at the center of the fixed base (9). The connecting plate (7) is coaxially installed on the annular boss, and its upper surface is coaxially connected to the bottom surface of the rotating inner shaft (1). The upper bearing (5) is installed on the bearing mounting position of the rotating inner shaft (1), and the inner pressure ring (3) of the bearing is threadedly connected to the rotating inner shaft (1) and presses on the inner ring of the upper bearing (5). The pressure transmitting component (8) is a claw-shaped support plate, and its bottom is installed on the pressure sensor. On the device (10), the claw extends from the groove of the annular boss; the pressure cylinder (13) is coaxially mounted on the upper part of the pressure guide (8), and the upper surface of the pressure cylinder (13) contacts the lower surface of the outer ring of the upper bearing (5); the pressure ring fixture (14) is a circular barrel structure with an open bottom, and the bottom is engaged with the inner pressure ring (3) of the bearing, and a torque wrench fixing groove is provided at the center of the top; the torque wrench (15) is engaged with the torque wrench fixing groove and is used to apply torque; the torque applied by the torque wrench (15) is transmitted to the inner pressure ring (3) of the bearing through the pressure ring fixture (14), the inner pressure ring (3) of the bearing applies pressure to the inner ring of the upper bearing (5), and then transmits it to the outer ring of the bearing through the ball, and finally applies it to the pressure cylinder (13), and transmits it to the pressure sensor (10) through the pressure transmission component (8); The pressure transmitting component (8) is a three-claw structure with an included angle of 120° between each other. The upper surfaces of the three claws are in the same plane. The edges of the three claws are coaxial with the center and have arc steps to ensure that the pressure cylinder (13) is coaxial with the pressure transmitting component (8) and radially limited. The bottom center of the pressure transmitting component (8) has a mounting groove, and the top of the pressure sensor (10) is fixed in the mounting groove by screws (11).

2. The preload measuring device for aerospace precision bearing assembly according to claim 1, characterized in that: The pressure sensor (10) is connected to a pressure digital display (12) for real-time display of the pressure value measured by the pressure sensor (10).

3. The preload measuring device for aerospace precision bearing assembly according to claim 1, characterized in that: The adapter plate (7) is a flange structure with coaxial annular steps on the upper and lower surfaces. The lower surface step is coaxially engaged with the annular boss of the fixed base (9), and the upper surface step is coaxially engaged with the inner diameter and bottom surface of the rotating inner shaft (1). The rotating inner shaft (1), the adapter plate (7) and the fixed base (9) are coaxially connected by screws (11).

4. The aerospace precision bearing assembly preload measuring device according to claim 1, characterized in that: The pressure cylinder (13) is a cylindrical cylinder with parallelism and flatness requirements on its upper and lower end faces. The pressure cylinder (13) transmits the preload of the bearing in the assembled state to the pressure transmission component (8).

5. The preload measuring device for aerospace precision bearing assembly according to claim 1, characterized in that: The fixed base (9) has a first groove at the center of its upper surface, and the pressure sensor (10) is installed in the first groove.

6. The preload measuring device for aerospace precision bearing assembly according to claim 1, characterized in that: The number of slots on the annular boss of the fixed base (9) corresponds one-to-one with the number of claws of the pressure transmission component (8). The fixed base (9) is fixed to the workbench by screws (11).

7. The preload measuring device for aerospace precision bearing assembly according to claim 1, characterized in that: A set of bosses are evenly distributed on the annular end face of the bottom of the pressure ring fixture (14), which engage with a set of second grooves evenly distributed on the inner pressure ring (3) of the bearing.

8. The preload measuring device for aerospace precision bearing assembly according to claim 2, characterized in that: The torque wrench (15) is a commercial adjustable torque wrench, the pressure sensor (10) is a commercial precision pressure sensor, and the pressure display (12) is a commercial pressure display. The pressure display (12) is used in conjunction with the pressure sensor (10).

9. A measurement method using the measuring device of claim 1, comprising the following steps: Step 1: Install the pressure sensor (10) in the first groove of the fixed base (9) with screws (11), and then fix the fixed base (9) on the workbench with screws (11); Step 2: Connect the pressure sensor (10) to the pressure digital display (12), turn on the power, and the pressure digital display (12) will display the pressure value; Step 3: Assemble the bottom mounting groove of the pressure transmission component (8) with the pressure sensor (10) and fix it with screws (11); Step 4: Assemble the bottom surface of the inner rotating shaft (1) with the upper surface step of the adapter plate (7) and fix it with screws (11); Assemble the lower surface step of the adapter plate (7) with the inner ring of the annular boss of the fixed base (9) and fix it with screws (11); Step 5: Place the pressure cylinder (13) on the pressure transmitting component (8) and match the arc step on the edge of the pressure transmitting component (8) to ensure that the pressure cylinder (13) and the pressure transmitting component (8) are coaxial; Step 6: Assemble the upper bearings (5) that need to be assembled back-to-back onto the rotating inner shaft (1). The lower surface of the outer ring of the upper bearing (5) contacts the upper surface of the pressure cylinder (13) until the value displayed by the pressure sensor (10) just changes. Step 7: Coaxially mount the bearing inner pressure ring (3) onto the rotating inner shaft (1), and gradually tighten the bearing inner pressure ring (3) using the pressure ring fixture (14) until the gap between the bearing inner pressure ring (3) and the upper bearing (5) is almost zero; clear the value of the pressure display (12) to zero. Step 8: Install the torque wrench (15) onto the pressure ring fixture (14), apply torque using the predetermined tightening torque, and stop applying torque immediately when the torque wrench (15) slips; observe the reading on the pressure display (12), and record the pressure value after the value stabilizes; the recorded pressure value is the axial preload applied to the bearing by the set torque; the axial preload of the bearing is expressed as: axial preload of the bearing = axial pressure of the bearing inner pressure ring - friction between the inner side wall of the bearing inner ring and the outer side wall of the rotating inner shaft; Step 9: Adjust the tightening torque. After obtaining the bearing preload that meets the usage requirements, record the corresponding tightening torque. During formal assembly, using this tightening torque will ensure that the bearing preload is consistent in each product of the same product shaft system.

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