Aviation main shaft tester for applying impact load and continuous centrifugal load and centrifugal loading method for simulating engine bearing test in blade falling state

Abstract

The invention discloses an aviation main shaft tester for applying an impact load and a continuous centrifugal load and a centrifugal loading method for simulating an engine bearing test in a blade falling state, and relates to the technical field of impact tests. The problems that an existing aviation main shaft bearing testing device can only apply stable loads and cannot apply impact loads and centrifugal loads at the same time are solved. One end of a spindle is connected with a spindle motor driving shaft through a flexible coupler, the spindle is rotationally connected with a base through a first accompanying test bearing and a tested bearing, a centrifugal loading unit is located on the side, close to the spindle motor, of the tested bearing, a permanent magnet is installed at the upper end of a straight rod, a coil assembly and the permanent magnet are arranged correspondingly, and the lower end of the straight rod is connected with a thrust block. The slopes on the two sides of the thrust block make contact with the two centrifugal blocks correspondingly, and the two centrifugal blocks are connected with the main shaft through the two compression springs correspondingly. The method is used for evaluating the reliability of the engine main shaft bearing which bears the instantaneous impact load and the continuous centrifugal load in the simulated rotor blade falling state.

Description

Technical Field

[0001] The invention relates to the technical field of impact testing, and 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 aircraft engines are in a complex vibration environment of high temperature, high pressure and high intensity throughout their life cycle. Long-term alternating loads make the stress concentration positions of the rotor blades prone to deformation and fracture. Impacts from larger foreign objects can also induce blade fracture. It is one of the components with the highest failure rate in aircraft engine use and experiments (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 the rotor blades places higher requirements on the performance of the 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 under the condition of simulated rotor blade shedding, design simulation tests for bearings working in this state, simulate the working conditions of main shaft bearings under the condition of missing engine blades, determine feasible load test loading methods and loading devices, and provide test conditions and test standards for the new aircraft engine main shaft bearings currently and subsequently developed. This evaluation system is mainly carried out through test methods. During the test, the instantaneous impact load and continuous centrifugal load applied to the test bearings are important indicators of the quality of the test process. The load applied during the assessment test should be consistent with the actual load. At present, the domestic aviation main shaft bearing test device can only apply stable loads, and there is no bearing test device that can apply impact loads and centrifugal loads at the same time. In order to provide basic data and test verification for the development of aviation bearing models, it is urgent to develop a performance assessment method and test device that can simulate the performance of aircraft engine main shaft bearings under the condition of blade shedding. 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 but cannot apply impact loads and centrifugal loads at the same time, and further to provide an aviation main shaft tester that applies impact loads and continuous centrifugal loads and a centrifugal loading method for testing engine bearings 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, wherein 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 tested 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 in the straight rod mounting hole. The upper end of the straight rod 106 is installed with a permanent magnet 101, and 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, and 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, and 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, and 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, 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.

[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. 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 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 also 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 5. The two test bearings 5 ​​are located in the spindle 9 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 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 a 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 implemented by the following steps:

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

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

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

[0018] 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 through the oil circuit control of the hydraulic system 3, and 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 at the same time;

[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, 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 tested 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 displacement of the thrust block 105 exceeds 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 be in a new limit state, which manifests as 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 realizes the application of non-contact impact load to the tested bearing when the spindle is driven by the spindle motor driving shaft to rotate at high speed, replacing the existing device for applying impact load by using physical direct contact, and proposes a method for applying non-contact impact load to the tested bearing with controllable times and load;

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

[0026] 3. The centrifugal block and the inside of the main shaft are connected by compression springs of the same type and initial compression amount, which have the functions of overload protection and buffering vibration reduction, and avoid the impact, vibration and noise caused by direct contact between the centrifugal block and the main shaft when the main shaft rotates at high speed;

[0027] 4. The present invention uses a control system in the centrifugal loading unit to control 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 for simulating engine bearing test under blade shedding state of the present invention fills the gap of the current domestic lack of centrifugal load loading method for simulating engine bearing under rotor blade damage state. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a 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 It is a structural schematic 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 group. 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, which 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 tested 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 in the straight rod mounting hole. The upper end of the straight rod 106 is installed with a permanent magnet 101, and 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, 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, left and right end faces of 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, 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 thrust blocks 105, two symmetrically arranged compression spring mounting holes are machined in the middle of the outer sides of the two centrifugal block motion cavities, 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 block 102 can be reasonably selected according to factors such as the applied load requirements, actual working conditions and installation space. The centrifugal load on the test bearing 7 under continuous operation can be calculated according to parameters such as the mass of the centrifugal block 102, the speed of the main shaft 9, and the center of mass offset distance of the centrifugal block 102; the contact angle and contact position of the wedge-shaped inclined surface between the thrust block 105 and the centrifugal block 102 can be reasonably designed according to the descending height of the thrust block 105, the width of the limiting groove of the centrifugal block 102 and the actual working conditions, so as to ensure that the thrust block 105 pushes the centrifugal block 102 in the process of transferring the load, so that its maximum displacement in 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 group 109, the magnitude of the DC current flowing through the coil and the current direction inside the coil group 109 can be changed according to the requirements of the applied load size and the load loading process under different working conditions; according to the current signal of the force sensor 104, the controller compares the current size and the distance between the coil group 109 and the main shaft 9 with the predetermined value, and the load transfer situation can be monitored in real time.

[0034] In this embodiment, the centrifugal loading unit 10 is located at 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 a disconnected state. The permanent magnet 101 is fixedly connected 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 with 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. When the straight rod 106 is radially displaced in the main shaft 9, a guide sleeve 107 is used for guidance to ensure that the load is transmitted in the axial direction, and the straight rod 106 is fixedly connected to the main shaft 9 by an oil retaining ring 108.

[0035] Specific implementation method 2: Combination Figure 1 and Figure 2 To explain this embodiment, the centrifugal loading unit 10 of this embodiment further includes a guide sleeve 107 and an oil retaining 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 retaining ring 108 is provided on the upper part of the guide sleeve 107. The oil retaining ring 108 is connected to the main shaft 9 through a plurality of connecting elements. With such a configuration, the straight rod 106 plays the role of transmitting load and supporting, and the guide sleeve 107. The oil retaining ring 108 is fixed to the main shaft 9, and the oil retaining ring 108 plays the role of preventing external dust and oil. 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, and 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 To explain this embodiment, the centrifugal loading unit 10 of this embodiment further includes two sealing rings, and the inner side surface of the guide sleeve 107 is provided with two sealing ring installation grooves in sequence from top to bottom along the axial direction, and the two sealing rings are respectively installed in the two sealing ring installation grooves, and the guide sleeve 107 is slidably sleeved on the straight rod 106, and the guide sleeve 107 is slidably sealed and connected to the straight rod 106 through the two sealing rings. Other components and connection relationships are the same as those of the first or second specific embodiments.

[0038] Specific implementation method four: Combination Figure 1 and Figure 2 To explain this embodiment, the centrifugal loading unit 10 of this embodiment further includes a force sensor 104. A force sensor mounting groove is provided in the middle of the lower surface of the thrust block motion cavity, and the force sensor 104 is mounted in the force sensor mounting groove. In this arrangement, the force sensor 104 is used to record the radial load and axial load applied by the radial loading unit 4 and the axial loading unit 8. Other components and connection relationships are the same as those of the first, second or third embodiments.

[0039] Specific implementation method five: Combination Figure 1 and Figure 2 To explain 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 connection relationships 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 arc surfaces, the center of the upper and lower surfaces of the centrifugal block 102 coincides with the center of the main shaft 9, the upper and lower surfaces of the centrifugal block movement cavity are 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. 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 explain this embodiment, the aviation main shaft tester of this embodiment also includes a radial loading unit 4 and two test bearings 2 5. The two test bearings 2 5 are located in the shaft section of the main shaft 9 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. With such an arrangement, the hydraulic cylinder in the radial loading unit 4 applies a radial load to the test bearing 5 through the spherical bearing and the radial loading member, and transmits the load to the test bearing 7 through the parts on the shaft, and the force sensor 104 records the applied load. Other components and connection relationships are the same as those of the specific embodiments one, two, three, four, five or six.

[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 already 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 French BCSA Bearing Company.

[0044] Specific implementation method eight: Combination Figure 1 and Figure 2 To explain this embodiment, the aviation spindle tester of this embodiment 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 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 control the oil circuit through the hydraulic system 3, and apply a load 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 already 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 CX-SD40×35 hydraulic cylinder produced by Dongguan Miaocheng Automation Co., Ltd., and the pump, control system and test bench adopt a SP190 pump, control system and test bench produced by French BCSA Bearing Company.

[0046] In this embodiment, the radial loading unit 4 and the axial loading unit 8 are used 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 To explain this embodiment, the end of the straight rod 106 of this embodiment is a threaded section, and the straight rod 106 is threadedly connected to the thrust block 105. This arrangement plays a role in transferring loads. Other components and connection relationships are the same as those of the specific embodiments one, two, three, four, five, six, seven or eight.

[0048] Specific implementation method ten: Combination Figure 1 and Figure 2 This embodiment is described. This embodiment also provides a centrifugal loading method for testing an engine bearing under a simulated blade shedding 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 runs to the target speed;

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

[0052] 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 tested 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 accompanying 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 tested bearing 7), and the load is transmitted to the tested bearing 7 through the parts on the shaft, and the applied load is recorded by the force sensor 104 at the same time; therefore, the tested 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, 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 tested 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 displacement of the thrust block 105 exceeds 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, and the centrifugal block 102 changes its center of mass position, the original dynamic balance state of the main shaft 9 is destroyed, and the rotational inertia of the shaft as a whole 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 a new limit state, and the test bearing 7 is shown as applying a continuous centrifugal load, so as to simulate the test bearing 7 being subjected to an impact load in the state of the rotor blade falling off, and then the test condition of applying a continuous centrifugal load is helpful for the subsequent assessment and evaluation of the bearing performance. In this way,. 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] Combination Figure 1 and Figure 2The working principle of the aviation spindle tester for applying impact load and continuous centrifugal load described in the present invention is described as follows: the thrust block 105 contacts the centrifugal block 102 through the wedge-shaped inclined surface, and the centrifugal block 102 is connected to the spindle 9 through the compression spring 103. The parameters of the springs on both sides are consistent and the initial length is consistent. The upper and lower polarities of the permanent magnet 101 are opposite to the direction of the magnetic field generated by the coil group 109 after power is turned on. When the centrifugal loading unit 10 is triggered, the DC power supply in the circuit is energized, and the coil group 109 with the iron core is charged to generate a magnetic field. The polarity of the permanent magnet is opposite to the direction of the magnetic field, and a magnetic repulsion force is generated on the permanent magnet 101. Since the main shaft 9 rotates at a high speed and the force action time is short, an impact load is applied to the test bearing 7 after the load is transferred. The load is transferred 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 leaves the limit groove. The sensor signal is compared with the predetermined value in the controller. If the predetermined value is not reached, the controller increases the magnetic field force by adjusting the current size in the circuit or the distance between the coil group 109 and the main shaft to achieve load transfer. The thrust block 105 contacts the centrifugal block 102 by the wedge-shaped inclined surface, and pushes it away in the vertical direction of the wedge-shaped inclined surface. A compression spring 103 is provided between the centrifugal block 102 and the main shaft 9 to play the role of overload protection and vibration absorption and vibration reduction. 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 a 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, and a continuous centrifugal load is applied 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 guide sleeve 107 and the compression spring 103 can be adjusted to achieve the reset of the aviation main shaft tester.

[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 the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. 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 embodiments of the present invention.

Claims

1. An aviation spindle tester for applying impact load and continuous centrifugal load, characterized in that: It 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) and close to the spindle. On one side of the motor (1), the centrifugal loading unit (10) comprises 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 arranged 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 respectively 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 side surfaces of the two centrifugal blocks (102) are both processed with inclined surfaces matching the thrust blocks (105). The middle parts of the outer side surfaces 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 (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 part of the guide sleeve (107); and the oil deflector (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 installation grooves in sequence from top to bottom along the axial direction. The two sealing rings are respectively installed in the two sealing ring installation grooves. The guide sleeve (107) is slidably sleeved 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, 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 also includes a radial loading unit (4) and two test bearings (5); the two test bearings (5) are located on the shaft section of the main shaft (9) between the test bearing (1) and the tested 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 (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 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 a sleeve. The hydraulic system (3) is connected to the radial loading unit (4) and the axial loading unit (8) 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 threadedly connected.

10. A centrifugal loading method for testing engine bearings in a simulated blade-off state based on the aviation main shaft tester applying impact load and continuous centrifugal load according to claim 9, characterized in that: The centrifugal loading method is achieved by the following steps: Step 1: Apply torque to the spindle (9): The spindle motor (1) is powered on and started, and the drive shaft of the spindle motor (1) drives the spindle (9) to run to a target speed through the flexible coupling (2); Step 2: applying radial load and axial load to the test bearing (7); A radial load unit (4) and an axial load unit (8) are used to apply radial load and axial load to two companion test bearings (5) and a test bearing (7) respectively according to the load spectrum under the actual working condition of the main shaft bearing of the aircraft engine through the oil circuit control of the hydraulic system (3), and 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 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), and a force is generated on the permanent magnet (101). When the high-speed running main shaft (9) drives the permanent magnet (101) to move in a vertical plane to the magnetic field, the magnetic field applies an impact load to the main shaft (9), and the load is applied to the test bearing (7) after being transmitted to the parts on the shaft; 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 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 centrifugal block (102) changes its center of mass position, 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 blades fall off.

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