Aviation spindle tester for applying impact load and continuous centrifugal load and centrifugal loading method for engine bearing testing under simulated blade shedding conditions

Abstract

An aviation main shaft tester for applying impact loads and continuous centrifugal loads and a centrifugal loading method for testing engine bearings in a simulated blade-off state relate to the technical field of impact testing. The present invention solves the problem that existing aviation main shaft bearing test devices can only apply stable loads and cannot apply impact loads and centrifugal loads at the same time. One end of the main shaft of the present invention is connected to the main shaft motor drive shaft through a flexible coupling, and the main shaft is rotatably connected to the base through a test bearing and a test bearing. The centrifugal loading unit is located on the side of the test bearing close to the main shaft motor. A permanent magnet is installed on the upper end of the straight rod, and the coil group is arranged corresponding to the permanent magnet. The lower end of the straight rod is connected to the thrust block. The inclined surfaces on both sides of the thrust block are in contact with two centrifugal blocks respectively, and the two centrifugal blocks are connected to the main shaft respectively through two compression springs. The present invention is used to realize the reliability evaluation of the engine main shaft bearing under the simulated rotor blade-off state to withstand instantaneous impact loads and continuous centrifugal loads.

Description

Technical Field

[0001] The present invention relates to the technical field of impact testing, in particular to an aviation main shaft tester for applying impact load and continuous centrifugal load, and a centrifugal loading method for testing an engine bearing in a simulated blade-off state. Background Art

[0002] As a high-speed rotating moving part, the rotor blades of an aircraft engine are in a complex vibration environment of high temperature, high pressure and high intensity throughout their entire life cycle. The long-term alternating load makes the stress concentration position of the rotor blades prone to deformation and fracture. The impact of larger foreign objects can also induce blade fracture. It is one of the components with the highest failure rate in aircraft engine use and testing (according to statistics, in aircraft engines, blade failures can account for more than 40% of the total failures). Bearings are key components connecting the engine main shaft and rotor blades. Damage or detachment of rotor blades places higher requirements on the performance of bearings. In fact, the falling of rotor blades will first impose a very large instantaneous impact load on the radial direction of the main shaft bearing. After the blades fall off, it will cause serious damage to the dynamic balance of the rotor, which is manifested as a continuous centrifugal load on the main shaft bearing of the engine. During the high-speed operation of the engine main shaft, long-term uneven load will cause the rolling elements inside the bearing to wear more severely and between the inner and outer rings of the bearing. Wear increases friction, and damage or cracks appear at the contact between the rolling elements and the inner and outer rings. Under the action of continuous centrifugal load, the cracks expand. At the same time, wear causes the internal temperature of the bearing to continue to rise, and the lubricant fails, which seriously affects the performance and service life of the engine main shaft bearing, resulting in reduced equipment operating efficiency, increased maintenance costs, and even affecting the overall service life of the engine. Therefore, it is urgent to establish a reliability evaluation system for engine main shaft bearings subjected to transient impact loads and sustained centrifugal loads under simulated rotor blade loss conditions. Simulation tests should be designed for bearings operating under these conditions, simulating the operating conditions of main shaft bearings under engine blade loss conditions. This should identify feasible load testing methods and devices, providing test conditions and standards for current and future development of new aircraft engine main shaft bearings. This evaluation system is primarily based on test methods. The transient impact loads and sustained centrifugal loads applied to the test bearings during the test are important indicators of the quality of the test process, and the loads applied during the assessment test should be consistent with actual conditions. Currently, domestic aircraft main shaft bearing test equipment can only apply steady loads; there is no bearing test equipment capable of simultaneously applying impact and centrifugal loads. To provide basic data and experimental verification for aircraft bearing model development, it is urgent to develop performance evaluation methods and test equipment that can simulate aircraft engine main shaft bearings under blade loss conditions. Summary of the Invention

[0003] The purpose of the present invention is to solve the problem that the existing aviation main shaft bearing test device can only apply stable loads and cannot apply impact loads and centrifugal loads at the same time, and further provide an aviation main shaft tester that applies impact loads and continuous centrifugal loads and a centrifugal loading method for engine bearing tests under simulated blade shedding conditions.

[0004] The technical solution of the present invention is:

[0005] An aviation spindle tester for applying impact load and continuous centrifugal load, comprising a spindle motor 1, a flexible coupling 2, a test bearing 1, a base 6, a test bearing 7, a spindle 9 and a centrifugal loading unit 10. The spindle 9 is arranged horizontally above the tester base, one end of the spindle 9 is connected to the drive shaft of the spindle motor 1 through the flexible coupling 2, the spindle motor 1 is mounted on the tester base, the spindle 9 is rotatably connected to the base 6 through the test bearing 1 and the test bearing 7, and the centrifugal loading unit 10 is located at The test bearing 7 is close to the side of the spindle motor 1. The centrifugal loading unit 10 includes a permanent magnet 101, a straight rod 106, a thrust block 105, two centrifugal blocks 102, two compression springs 103 and a coil group 109. The spindle 9 is provided with a straight rod mounting hole arranged radially. The straight rod 106 is coaxially slidably inserted into the straight rod mounting hole. The upper end of the straight rod 106 is mounted with a permanent magnet 101. The permanent magnet 101 is an arc-shaped permanent magnet. The base 6 is provided with a coil group 109 with an iron core. The coil group 109 is installed on the base 6, and the coil group 109 is arranged corresponding to the permanent magnet 101. A thrust block motion cavity is provided below the straight rod mounting hole. The thrust block 105 is slidably arranged in the thrust block motion cavity. The upper end of the thrust block 105 is connected to the lower end of the straight rod 106. The left and right end faces of the thrust block 105 are symmetrically arranged inclined surfaces. Two symmetrically arranged centrifugal block motion cavities are respectively provided on the left and right sides of the thrust block motion cavity. The two centrifugal block motion cavities are both connected to the thrust block motion cavity. The two centrifugal blocks 102 are respectively arranged in the two centrifugal block motion cavities. The inner sides of the two centrifugal blocks 102 are both machined with inclined surfaces matching the thrust blocks 105. The middle parts of the outer sides of the two centrifugal block motion cavities are both machined with two symmetrically arranged compression spring mounting holes. The two compression springs 103 are respectively coaxially mounted in the two compression spring mounting holes. One end of the compression spring 103 contacts the bottom surface of the compression spring mounting hole, and the other end of the compression spring 103 contacts the outer side surface of the centrifugal block 102.

[0006] Furthermore, the centrifugal loading unit 10 also includes a guide sleeve 107 and an oil deflector 108. A guide sleeve mounting hole coaxially arranged with the straight rod mounting hole is opened on the side of the main shaft 9. The guide sleeve 107 is inserted into the guide sleeve mounting hole. A coaxially arranged oil deflector 108 is provided on the upper part of the guide sleeve 107. The oil deflector 108 is connected to the main shaft 9 through multiple connecting elements.

[0007] Furthermore, the centrifugal loading unit 10 also includes two sealing rings. Two sealing ring mounting grooves are provided on the inner side surface of the guide sleeve 107 in sequence from top to bottom along the axial direction. The two sealing rings are respectively installed in the two sealing ring mounting grooves. The guide sleeve 107 is slidably mounted on the straight rod 106. The guide sleeve 107 is slidably sealed and connected to the straight rod 106 through the two sealing rings.

[0008] Furthermore, the centrifugal loading unit 10 also includes a force sensor 104. A force sensor installation groove is provided in the middle of the lower surface of the thrust block movement cavity, and the force sensor 104 is installed in the force sensor installation groove.

[0009] Furthermore, the centrifugal loading unit 10 further includes a DC power supply and a controller. The coil assembly 109 is connected to the DC power supply via a wire, the DC power supply is connected to the controller via a wire, and the controller is connected to the coil assembly 109 via a wire.

[0010] Furthermore, the upper and lower surfaces of the centrifugal block 102 are both arc surfaces, the centers of the upper and lower surfaces of the centrifugal block 102 coincide with the center of the main shaft 9, the upper and lower surfaces of the centrifugal block motion cavity are both arc surfaces, and the center of the centrifugal block motion cavity coincides with the center of the main shaft 9, a right-angle limit protrusion is provided on the upper inner side of the centrifugal block motion cavity, and a limit groove matching the right-angle limit protrusion is provided on the upper inner side of the centrifugal block 102.

[0011] Furthermore, the aviation spindle tester also includes a radial loading unit 4 and two test bearings 2 5. The two test bearings 2 5 are located in the spindle 9 shaft section between the test bearing 1 and the test bearing 7. The radial loading unit 4 is arranged inside the base 6, and the radial loading unit 4 is connected to the two test bearings 2 5.

[0012] Furthermore, the aviation spindle tester also includes an axial loading unit 8 and a hydraulic system 3. The axial loading unit 8 is located on the side of the test bearing 7 away from the spindle motor 1. The piston rod of the hydraulic cylinder at the end of the axial loading unit 8 contacts the outer ring of the test bearing 7 through the sleeve. The hydraulic system 3 is connected to the radial loading unit 4 and the axial loading unit 8 through hydraulic oil pipes respectively.

[0013] Furthermore, the end of the straight rod 106 is a threaded section, and the straight rod 106 and the thrust block 105 are threadedly connected.

[0014] The present invention also provides a centrifugal loading method for testing an engine bearing under a simulated blade-off state based on the aviation main shaft tester that applies an impact load and a continuous centrifugal load. The centrifugal loading method is achieved by the following steps:

[0015] Step 1: Apply torque to the spindle 9:

[0016] The spindle motor 1 is powered on and starts, and the spindle motor 1 drives the spindle 9 to run to the target speed through the flexible coupling 2;

[0017] Step 2: Apply radial load and axial load to the test bearing 7;

[0018] According to the load spectrum of the actual working conditions of the aircraft engine main shaft bearing, radial load and axial load are applied to the two accompanying test bearings 5 ​​and the test bearing 7 respectively through the radial loading unit 4 and the axial loading unit 8 through the oil circuit control of the hydraulic system 3. The load is transmitted to the test bearing 7 through the parts on the shaft, and the applied load is recorded by the force sensor 104.

[0019] Step 3: Apply impact load to the test bearing 7:

[0020] When the impact load is applied, a command is sent to the controller, the DC power supply starts to be energized, and the coil group 109 generates a magnetic field after being energized. The direction of the magnetic field is opposite to the upper and lower polarities of the permanent magnet 101, which generates a force on the permanent magnet 101. When the high-speed running main shaft 9 drives the permanent magnet 101 to run in the vertical plane into the magnetic field, the magnetic field applies an impact load to the main shaft 9. After the load is transferred to the parts on the shaft, the impact load is applied to the test bearing 7.

[0021] Step 4: Apply a continuous centrifugal load to the test bearing 7:

[0022] After the magnetic field applies an impact load to the permanent magnet 101, the load pushes the thrust block 105 through the straight rod 106. The thrust block 105 is displaced beyond the distance of the limit groove through the inclined surface. Since the main shaft 9 is in a high-speed rotation state, the centrifugal block 102 moves to a new limit state under the action of the centrifugal load. The center of mass position of the centrifugal block 102 changes, the original dynamic balance state of the main shaft 9 is destroyed, and the overall rotational inertia of the shaft changes, that is, a centrifugal load is applied to the test bearing 7. Before the main shaft 9 stops running, the centrifugal block 102 will remain in the new limit state, which appears to be a continuous centrifugal load applied to the test bearing 7, so as to simulate the impact load of the test bearing 7 when the rotor blade falls off.

[0023] Compared with the prior art, the present invention has the following effects:

[0024] 1. The present invention applies a non-contact impact load to the test bearing while the spindle is rotating at high speed driven by the spindle motor drive shaft. This replaces the existing device for applying impact loads that uses direct physical contact and proposes a method for applying non-contact impact loads to the test bearing with controllable times and loads.

[0025] 2. The present invention realizes closed-loop control of non-contact impact loads. Through mechanical components such as straight rods, thrust blocks and force sensors, it achieves effective transmission of load paths, which is beneficial to subsequent load transformation.

[0026] 3. The centrifugal block and the spindle are connected by compression springs of the same type and initial compression amount, which have the functions of overload protection and buffering and vibration reduction. When the spindle rotates at high speed, the impact, vibration and noise generated by direct contact between the centrifugal block and the spindle are avoided.

[0027] 4. The present invention uses a control system in the centrifugal loading unit to control the magnetic force of the magnetic field generated by the coil group by monitoring the current in the circuit and the displacement sensor to monitor the displacement from the circuit to the main shaft, so as to apply corresponding magnetic force to the main shaft permanent magnet according to demand.

[0028] 5. The centrifugal loading method of the present invention for simulating engine bearing testing under blade-off conditions fills the current domestic gap in the lack of a method for simulating the centrifugal load on engine bearings under rotor blade damage conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the structure of the aviation spindle tester for applying impact load and continuous centrifugal load according to the present invention;

[0030] Figure 2 1 is a schematic structural diagram of a centrifugal loading unit 10 in an aviation spindle tester for applying impact load and continuous centrifugal load according to the present invention.

[0031] In the figure: 1. Spindle motor; 2. Flexible coupling; 3. Hydraulic system; 4. Radial loading unit; 5. Test bearing 2; 6. Base; 7. Test bearing; 8. Axial loading unit; 9. Spindle; 10. Centrifugal loading unit; 101. Permanent magnet; 102. Centrifugal block; 103. Compression spring; 104. Force sensor; 105. Thrust block; 106. Straight rod; 107. Guide sleeve; 108. Oil retaining ring; 109. Coil assembly. DETAILED DESCRIPTION

[0032] Specific implementation method 1: Combination Figure 1 and Figure 2The present embodiment is described. The present embodiment is an aviation spindle tester for applying impact load and continuous centrifugal load. It includes a spindle motor 1, a flexible coupling 2, a test bearing 1, a base 6, a test bearing 7, a spindle 9 and a centrifugal loading unit 10. The spindle 9 is arranged horizontally above the tester base. One end of the spindle 9 is connected to the drive shaft of the spindle motor 1 through the flexible coupling 2. The spindle motor 1 is installed on the tester base. The spindle 9 is rotatably connected to the base 6 through the test bearing 1 and the test bearing 7. The centrifugal loading unit 10 is located on the side of the test bearing 7 close to the spindle motor 1. The centrifugal loading unit 10 includes a permanent magnet 101, a straight rod 106, a thrust block 105, two centrifugal blocks 102, two compression springs 103 and a coil group 109. The spindle 9 is provided with a straight rod mounting hole arranged radially. The straight rod 106 is coaxially slidably inserted into the straight rod mounting hole. The upper end of the straight rod 106 is installed with a permanent magnet 101. The permanent magnet 101 is an arc-shaped permanent magnet. The base 6 is provided with a Coil group 109, coil group 109 is installed on base 6, coil group 109 is arranged corresponding to permanent magnet 101, a thrust block motion cavity is provided below the straight rod mounting hole, thrust block 105 is slidably arranged in the thrust block motion cavity, the upper end of thrust block 105 is connected to the lower end of straight rod 106, the left and right end faces of thrust block 105 are symmetrically arranged inclined surfaces, and two symmetrically arranged centrifugal block motion cavities are respectively provided on the left and right sides of the thrust block motion cavity, and the two centrifugal block motion cavities are both connected to the thrust block motion cavity. The two centrifugal blocks 102 are respectively provided in the two centrifugal block motion cavities, and the inner sides of the two centrifugal blocks 102 are both machined with inclined surfaces matching the thrust blocks 105. The middle parts of the outer sides of the two centrifugal block motion cavities are both machined with two symmetrically arranged compression spring mounting holes, and the two compression springs 103 are respectively coaxially mounted in the two compression spring mounting holes, one end of the compression spring 103 contacts the bottom surface of the compression spring mounting hole, and the other end of the compression spring 103 contacts the outer side surface of the centrifugal block 102.

[0033] In this embodiment, the mass, material, and shape of the centrifugal mass 102 can be reasonably selected based on factors such as the applied load requirements, actual operating conditions, and installation space. The centrifugal load on the test bearing 7 during continuous operation can be calculated based on parameters such as the mass of the centrifugal mass 102, the speed of the spindle 9, and the offset distance of the center of mass of the centrifugal mass 102. The contact angle and contact position of the wedge-shaped inclined surface between the thrust block 105 and the centrifugal mass 102 can be reasonably designed based on the descending height of the thrust block 105, the width of the limiting groove of the centrifugal mass 102, and actual operating conditions, to ensure that the thrust block 105 pushes the centrifugal mass 102 during load transfer so that its maximum displacement along the vertical direction of the wedge-shaped inclined surface exceeds the width of the limiting groove. According to Ampere's law F=BIL, the number of turns of the coil assembly 109, the magnitude of the DC current flowing through the coil, and the direction of the current within the coil assembly 109 can be changed according to the magnitude of the applied load and the requirements of the load loading process under different operating conditions. Based on the current signal of the force sensor 104, the controller compares the current magnitude and the distance between the coil assembly 109 and the spindle 9 with a predetermined value to monitor the load transfer in real time.

[0034] In this embodiment, the centrifugal loading unit 10 is located in the main shaft section close to the test bearing 7, the coil group 109 is fixed to the base 6 around the iron core, and is connected to the power supply and the controller. When the bearing is operating normally, the power supply is in the disconnected state, the permanent magnet 101 is fixed to the straight rod 106, and the threaded section at the end of the straight rod 106 is connected to the thrust block 105. The thrust block 105 and the centrifugal block 102 are in contact through a wedge-shaped inclined surface at a certain angle. The centrifugal block 102 is connected to the inside of the main shaft 9 through a compression spring 103, and a limit groove is used for lateral limitation. The straight rod 106 is guided by a guide sleeve 107 when the main shaft 9 is radially displaced to ensure that the load is transmitted in the direction of the axis, and is fixed to the main shaft 9 by an oil retaining ring 108.

[0035] Specific implementation method 2: Combination Figure 1 and Figure 2 To describe this embodiment, the centrifugal loading unit 10 of this embodiment further includes a guide sleeve 107 and an oil deflector 108. A guide sleeve mounting hole coaxially arranged with the straight rod mounting hole is provided on the side of the main shaft 9. The guide sleeve 107 is inserted into the guide sleeve mounting hole. A coaxially arranged oil deflector 108 is provided on the upper portion of the guide sleeve 107. The oil deflector 108 is connected to the main shaft 9 through a plurality of connecting elements. With this arrangement, the straight rod 106 plays the role of transmitting load and supporting, and the guide sleeve 107 is fixed to the main shaft 9 by the oil deflector 108, which plays the role of preventing external dust and oil stains. Other components and connection relationships are the same as those of the first specific embodiment.

[0036] In this embodiment, the rotation axis of the straight rod 106 needs to intersect with the axis of the main shaft 9 after extension. The guide sleeve 107 and the straight rod 106 are clearance-fitted and distributed along the circumference of the straight rod 106 to guide the instantaneous load to be transmitted toward the axial direction.

[0037] Specific implementation method three: Combination Figure 1 and Figure 2 This embodiment describes the centrifugal loading unit 10, which further includes two sealing rings. Two sealing ring mounting grooves are defined axially from top to bottom on the inner side of the guide sleeve 107. The two sealing rings are mounted in the grooves, respectively. The guide sleeve 107 is slidably mounted on the straight rod 106, and the guide sleeve 107 is slidably and sealingly connected to the straight rod 106 via the two sealing rings. Other components and connections are the same as those in the first or second embodiment.

[0038] Specific implementation method four: Combination Figure 1 and Figure 2 To explain this embodiment, the centrifugal loading unit 10 also includes a force sensor 104. A force sensor mounting slot is defined in the middle of the lower surface of the thrust block's motion cavity, and force sensor 104 is mounted within this slot. This arrangement allows force sensor 104 to record the radial and axial loads applied by the radial loading unit 4 and the axial loading unit 8. The remaining components and connections are identical to those in the first, second, or third embodiments.

[0039] Specific implementation method five: Combination Figure 1 and Figure 2 To describe this embodiment, the centrifugal loading unit 10 of this embodiment further includes a DC power supply and a controller. The coil assembly 109 is connected to the DC power supply via a wire, the DC power supply is connected to the controller via a wire, and the controller is connected to the coil assembly 109 via a wire. Other components and connections are the same as those of the first, second, third, or fourth embodiments.

[0040] Specific implementation method six: combination Figure 1 and Figure 2 This embodiment is described. The upper and lower surfaces of the centrifugal block 102 of this embodiment are both arcuate surfaces. The centers of the upper and lower surfaces of the centrifugal block 102 coincide with the center of the main shaft 9. The upper and lower surfaces of the centrifugal block movement cavity are both arcuate surfaces. The center of the centrifugal block movement cavity coincides with the center of the main shaft 9. A right-angled stop protrusion is provided on the upper inner portion of the centrifugal block movement cavity. A stop groove matching the right-angled stop protrusion is provided on the upper inner portion of the centrifugal block 102. Other components and connection relationships are the same as those of the first, second, third, fourth, or fifth embodiments.

[0041] Specific implementation method seven: combination Figure 1 and Figure 2To describe this embodiment, the aviation spindle tester also includes a radial loading unit 4 and two test bearings 5. The two test bearings 5 ​​are located on the spindle 9 between the test bearing 1 and the test bearing 7. The radial loading unit 4 is disposed within the base 6 and connected to the two test bearings 5. With this configuration, the hydraulic cylinder in the radial loading unit 4 applies a radial load to the test bearings 5 ​​via the spherical bearing and radial loading element. This load is then transferred to the test bearing 7 via components on the shaft, and a force sensor 104 records the applied load. Other components and connections are the same as those in Specific Embodiments 1, 2, 3, 4, 5, or 6.

[0042] In this embodiment, the test bearing 1, the tested bearing 7 and the two test bearings 2 5 are all fixed by shaft parts such as sleeves, oil baffles, shaft end baffles, bases 6 and seals.

[0043] Among them, the radial loading unit 4 adopts products sold on the market. The radial loading unit 4 includes three main parts, namely a hydraulic cylinder, a pump and a control system. The hydraulic cylinder adopts a hydraulic cylinder of model CX-SD40×35 produced by Dongguan Miaocheng Automation Co., Ltd., and the pump, control system and test bench adopt a pump, control system and test bench of model SP190 produced by France BCSA Bearing Company.

[0044] Specific implementation method eight: combination Figure 1 and Figure 2 To describe this embodiment, the aviation spindle tester of this embodiment further includes an axial loading unit 8 and a hydraulic system 3. The axial loading unit 8 is located on the side of the test bearing 7 away from the spindle motor 1. The axial loading unit 8 executes the end hydraulic cylinder piston rod to contact the outer ring of the test bearing 7 through the sleeve. The hydraulic system 3 is connected to the radial loading unit 4 and the axial loading unit 8 through hydraulic oil pipes. With this arrangement, the axial loading unit 8 executes the end hydraulic cylinder piston rod to apply a load to the outer ring of the test bearing 7 through the sleeve. The radial loading unit 4 and the axial loading unit 8 are controlled by the hydraulic system 3 for oil circuit control, and load is applied to the test bearing 7 according to the actual operating conditions of the aircraft engine bearing. Other components and connection relationships are the same as those of specific embodiments one, two, three, four, five, six or seven.

[0045] Among them, the axial loading unit 8 adopts products sold on the market. The axial loading unit 8 includes three main parts, namely a hydraulic cylinder, a pump and a control system. The hydraulic cylinder adopts a hydraulic cylinder of model CX-SD40×35 produced by Dongguan Miaocheng Automation Co., Ltd., and the pump, control system and test bench adopt a pump, control system and test bench of model SP190 produced by France BCSA Bearing Company.

[0046] In this embodiment, the radial loading unit 4 and the axial loading unit 8 act to apply the radial and axial loads that the main shaft bearing is subjected to when the aircraft engine is operating normally to the test bearing 7, and the control system applies the load to the test bearing 7 according to the load spectrum under the actual operation of the engine.

[0047] Specific implementation method nine: Combination Figure 1 and Figure 2 In this embodiment, the end of the straight rod 106 is threaded, and the straight rod 106 is threadedly connected to the thrust block 105. This arrangement facilitates load transfer. The remaining components and connections are identical to those in Embodiments 1, 2, 3, 4, 5, 6, 7, or 8.

[0048] Specific implementation method ten: Combination Figure 1 and Figure 2 This embodiment further provides a centrifugal loading method for testing an engine bearing under a simulated blade-off state based on the aviation main shaft tester that applies impact load and continuous centrifugal load. The centrifugal loading method is implemented by the following steps:

[0049] Step 1: Apply torque to the spindle 9:

[0050] The spindle motor 1 is powered on, and the spindle motor 1 drives the shaft to rotate, driving the flexible coupling 2 and the spindle 9 to rotate until the spindle 9 reaches the target speed;

[0051] Step 2: Apply radial load and axial load to the test bearing 7;

[0052] According to the load spectrum of the actual working conditions of the aircraft engine main shaft bearing, radial loads and axial loads are applied to the two test bearings 5 ​​and the test bearing 7 respectively through the radial loading unit 4 and the axial loading unit 8 through the oil circuit control of the hydraulic system 3 (the radial loading unit 4 executes the end hydraulic cylinder to apply radial load to the test bearing 5 through the spherical bearing and the radial loading member, and the axial loading unit 8 executes the end hydraulic cylinder to act on the sleeve to apply axial load to the outer ring of the test bearing 7). The load is transmitted to the test bearing 7 through the parts on the shaft, and the applied load is recorded by the force sensor 104. Therefore, the test bearing 7 first operates under normal load conditions, and the applied load is consistent with the actual load.

[0053] Step 3: Apply impact load to the test bearing 7:

[0054] When the impact load is applied, a command is sent to the controller, the DC power supply starts to be energized, and the coil group 109 generates a magnetic field after being energized. The direction of the magnetic field is opposite to the upper and lower polarities of the permanent magnet 101, which generates a force on the permanent magnet 101. When the high-speed running main shaft 9 drives the permanent magnet 101 to run in the vertical plane into the magnetic field, the magnetic field applies an impact load to the main shaft 9. After the load is transferred to the parts on the shaft, the impact load is applied to the test bearing 7.

[0055] Step 4: Apply a continuous centrifugal load to the test bearing 7:

[0056] After the magnetic field applies an impact load to the permanent magnet 101, the load pushes the thrust block 105 through the straight rod 106. The thrust block 105 is displaced beyond the distance of the limit groove by the inclined surface. Since the main shaft 9 is in a high-speed rotation state, the centrifugal block 102 moves to a new limit state under the action of the centrifugal load, the center of mass position of the centrifugal block 102 changes, the original dynamic balance state of the main shaft 9 is destroyed, and the overall rotational inertia of the shaft changes, that is, a centrifugal load is applied to the test bearing 7. Before the main shaft 9 stops running, the centrifugal block 102 will remain in the new limit state, and the test bearing 7 is subjected to a continuous centrifugal load, thereby simulating the test bearing 7 being subjected to an impact load in the state of rotor blade shedding, followed by a test condition of continuous centrifugal load application, which is helpful for subsequent bearing performance assessment and evaluation. With such an arrangement, the other components and connection relationships are the same as those of the first, second, third, fourth, fifth, sixth, seventh, eighth, or ninth embodiment.

[0057] How it works

[0058] Combine Figure 1 and Figure 2The operating principle of the aviation spindle tester for applying impact and continuous centrifugal loads described herein is explained as follows: The thrust block 105 contacts the centrifugal block 102 via a wedge-shaped slope. The centrifugal block 102 is connected to the spindle 9 via a compression spring 103. The springs on both sides have identical parameters and initial lengths. The upper and lower polarities of the permanent magnet 101 are opposite to the magnetic field generated by the coil assembly 109 when energized. When the centrifugal loading unit 10 is triggered, the DC power supply in the circuit is energized, and the coil assembly 109 with an iron core is charged to generate a magnetic field. The polarity of the permanent magnet is opposite to the direction of the generated magnetic field, which produces a magnetic repulsion force on the permanent magnet 101. Due to the high speed of the main shaft 9 and the short force application time, the load is immediately applied to the test bearing 7 after the load is transferred. The load is transmitted along the path of the permanent magnet 101, the straight rod 106, and the thrust block 105. The force sensor 104 records the displacement of the thrust block 105 to determine whether the centrifugal block 102 has left the limit slot. The sensor signal is compared with a predetermined value in the controller. If the predetermined value is not reached, the controller increases the magnetic field force by adjusting the current in the circuit or the distance between the coil assembly 109 and the main shaft to achieve load transfer. The thrust block 105 contacts the centrifugal block 102 with a wedge-shaped inclined surface, pushing it away in the direction perpendicular to the wedge-shaped inclined surface. A compression spring 103 is installed between the centrifugal block 102 and the main shaft 9 to provide overload protection and vibration absorption and buffering. Since the main shaft 9 is in a high-speed rotation state, the centrifugal block 102 is always subjected to a large centrifugal force. When the maximum displacement of the centrifugal block 102 reaches the length of the limit groove, the centrifugal block 102 moves radially to a new limit state under the action of the large centrifugal force. The center of mass position changes, causing the original dynamic balance state of the main shaft 9 to change, that is, a centrifugal load is applied to the test bearing 7. Before the high-speed rotation of the main shaft 9 stops, the centrifugal block 102 is in a new limit state, applying a continuous centrifugal load to the test bearing 7. In the above process, the test bearing 7 works under normal working conditions, and the applied load is consistent with the actual situation. The centrifugal loading unit 10 is started, and an impact load is applied to the test bearing 7. The load is transmitted through a mechanical device and converted into a continuous centrifugal load. Therefore, a test loading method for engine bearings to withstand impact and centrifugal loads is proposed, which is conducive to the subsequent simulation performance test and assessment of the test bearing 7.

[0059] After the main shaft 9 stops rotating, the aviation main shaft tester can be reset by adjusting the guide sleeve 107 and the compression spring 103.

[0060] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An aviation spindle tester for applying impact load and continuous centrifugal load, characterized by: The tester comprises a spindle motor (1), a flexible coupling (2), a test bearing (1), a base (6), a test bearing (7), a spindle (9) and a centrifugal loading unit (10). The spindle (9) is arranged horizontally above the tester base. One end of the spindle (9) is connected to the drive shaft of the spindle motor (1) through the flexible coupling (2). The spindle motor (1) is mounted on the tester base. The spindle (9) is rotatably connected to the base (6) through the test bearing (1) and the test bearing (7). The centrifugal loading unit (10) is located near the test bearing (7) near the spindle. On one side of the motor (1), the centrifugal loading unit (10) includes a permanent magnet (101), a straight rod (106), a thrust block (105), two centrifugal blocks (102), two compression springs (103) and a coil group (109). A straight rod mounting hole arranged radially is provided inside the main shaft (9). The straight rod (106) is coaxially slidably inserted into the straight rod mounting hole. A permanent magnet (101) is installed on the upper end of the straight rod (106). The permanent magnet (101) is an arc-shaped permanent magnet. A coil group (109) with an iron core is provided inside the base (6). 09), the coil group (109) is installed on the base (6), the coil group (109) is arranged corresponding to the permanent magnet (101), a thrust block movement cavity is provided below the straight rod installation hole, the thrust block (105) is slidably provided in the thrust block movement cavity, the upper end of the thrust block (105) is connected to the lower end of the straight rod (106), the left and right end faces of the thrust block (105) are symmetrically arranged inclined surfaces, and two symmetrically arranged centrifugal block movement cavities are provided on the left and right sides of the thrust block movement cavity, and the two centrifugal block movement cavities are both connected to the thrust block movement cavity. The cavities are connected, and two centrifugal blocks (102) are respectively arranged in the two centrifugal block movement cavities. The inner sides of the two centrifugal blocks (102) are both processed with inclined surfaces that match the thrust blocks (105). The middle parts of the outer sides of the two centrifugal block movement cavities are both processed with two symmetrically arranged compression spring mounting holes. The two compression springs (103) are respectively coaxially mounted in the two compression spring mounting holes. One end of the compression spring (103) contacts the bottom surface of the compression spring mounting hole, and the other end of the compression spring (103) contacts the outer side surface of the centrifugal block (102).

2. The aviation spindle tester for applying impact load and continuous centrifugal load according to claim 1, characterized in that: The centrifugal loading unit (10) further comprises a guide sleeve (107) and an oil deflector ring (108). A guide sleeve mounting hole coaxially arranged with the straight rod mounting hole is provided on the side of the main shaft (9). The guide sleeve (107) is inserted into the guide sleeve mounting hole. A coaxially arranged oil deflector ring (108) is provided on the upper portion of the guide sleeve (107). The oil deflector ring (108) is connected to the main shaft (9) via a plurality of connecting elements.

3. The aviation spindle tester for applying impact load and continuous centrifugal load according to claim 2, characterized in that: The centrifugal loading unit (10) further comprises two sealing rings. The inner side surface of the guide sleeve (107) is provided with two sealing ring mounting grooves in sequence from top to bottom along the axial direction. The two sealing rings are respectively mounted in the two sealing ring mounting grooves. The guide sleeve (107) is slidably mounted on the straight rod (106). The guide sleeve (107) is slidably sealedly connected to the straight rod (106) via the two sealing rings.

4. The aviation spindle tester for applying impact load and continuous centrifugal load according to claim 3, characterized in that: The centrifugal loading unit (10) also includes a force sensor (104). A force sensor installation groove is provided in the middle of the lower surface of the thrust block movement cavity, and the force sensor (104) is installed in the force sensor installation groove.

5. The aviation spindle tester for applying impact load and continuous centrifugal load according to claim 4, characterized in that: The centrifugal loading unit (10) further comprises a DC power supply and a controller. The coil assembly (109) is connected to the DC power supply via a wire, the DC power supply is connected to the controller via a wire, and the controller is connected to the coil assembly (109) via a wire.

6. The aviation spindle tester for applying impact load and continuous centrifugal load according to claim 1 or 5, characterized in that: The upper and lower surfaces of the centrifugal block (102) are both arc surfaces, the centers of the upper and lower surfaces of the centrifugal block (102) coincide with the center of the main shaft (9), the upper and lower surfaces of the centrifugal block movement cavity are both arc surfaces, and the center of the centrifugal block movement cavity coincides with the center of the main shaft (9), a right-angled limiting protrusion is provided on the upper inner side of the centrifugal block movement cavity, and a limiting groove matching the right-angled limiting protrusion is provided on the upper inner side of the centrifugal block (102).

7. The aviation spindle tester for applying impact load and continuous centrifugal load according to claim 6, characterized in that: The aviation main shaft tester further comprises a radial loading unit (4) and two accompanying test bearings (5), wherein the two accompanying test bearings (5) are located on the main shaft (9) shaft section between the accompanying test bearing (1) and the tested bearing (7), and the radial loading unit (4) is arranged inside the base (6), and the radial loading unit (4) is connected to the two accompanying test bearings (5).

8. The aviation spindle tester for applying impact load and continuous centrifugal load according to claim 7, characterized in that: The aviation spindle tester further comprises an axial loading unit (8) and a hydraulic system (3). The axial loading unit (8) is located on the side of the test bearing (7) away from the spindle motor (1). The piston rod of the hydraulic cylinder at the end of the axial loading unit (8) contacts the outer ring of the test bearing (7) through a sleeve. The hydraulic system (3) is connected to the radial loading unit (4) and the axial loading unit (8) respectively through hydraulic oil pipes.

9. The aviation spindle tester for applying impact load and continuous centrifugal load according to claim 1 or 8 is characterized in that the end of the straight rod (106) is a threaded section, and the straight rod (106) and the thrust block (105) are connected by threads.

10. A centrifugal loading method for testing engine bearings in a simulated blade-off state based on the aviation main shaft tester that applies impact loads and continuous centrifugal loads as claimed in claim 9, characterized in that: The centrifugal loading method is achieved by the following steps: Step 1: Apply torque to the main shaft (9): The spindle motor (1) is powered on and started, and the spindle motor (1) drives the spindle (9) to run to the target speed via the flexible coupling (2); Step 2: applying radial load and axial load to the test bearing (7); According to the load spectrum of the actual working condition of the main shaft bearing of the aircraft engine, radial load and axial load are applied to the two accompanying test bearings (5) and the test bearing (7) respectively through the radial loading unit (4) and the axial loading unit (8), and the oil circuit control of the hydraulic system (3), the load is transmitted to the test bearing (7) through the parts on the shaft, and the applied load is recorded by the force sensor (104); Step 3: Apply impact load to the test bearing (7): When an impact load is applied, a command is sent to the controller, the DC power supply starts to be energized, and the coil group (109) generates a magnetic field after being energized. The direction of the magnetic field is opposite to the upper and lower polarities of the permanent magnet (101), and a force is generated on the permanent magnet (101). When the high-speed running main shaft (9) drives the permanent magnet (101) to run in a vertical plane to the magnetic field, the magnetic field applies an impact load to the main shaft (9). After the load is transferred to the parts on the shaft, the impact load is applied to the test bearing (7); Step 4: Apply a continuous centrifugal load to the test bearing (7): After the magnetic field applies an impact load to the permanent magnet (101), the load pushes the thrust block (105) through the straight rod (106). The thrust block (105) is displaced by the inclined surface to exceed the distance of the limit groove. Since the main shaft (9) is in a high-speed rotation state, the centrifugal block (102) moves to a new limit state under the action of the centrifugal load, the center of mass position of the centrifugal block (102) changes, the original dynamic balance state of the main shaft (9) is destroyed, and the rotational inertia of the entire shaft changes, that is, a centrifugal load is applied to the test bearing (7). Before the main shaft (9) stops running, the centrifugal block (102) will always be in the new limit state, and the test bearing (7) is subjected to a continuous centrifugal load, so as to simulate the test bearing (7) being subjected to an impact load when the rotor blade falls off.

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