A simulation test bench for analyzing the vibration characteristics of coaxial counter-rotating propeller fan structures

Abstract

The present invention discloses a simulation test bench for analyzing the vibration characteristics of a coaxial counter-rotating propeller fan structure, including an inner rotor drive motor, an outer rotor drive motor, a motor bracket, a synchronous belt and pulley, an inner and outer rotor, an inner and outer rotor test weight plate, a front propeller, a rear propeller, a tensioning wheel, a front and rear bearing bracket, a base, and a bracket adjustment block; the dual-rotor counter-rotating propeller fan engine has the advantages of low fuel consumption and high propulsion efficiency, and is the development direction of engines for strategic transport aircraft and long-range bombers. Through the coordinated cooperation of different mechanical parts, the coaxial corotation of the inner and outer dual rotors, the coaxial counterrotation, the forward and reverse rotation of the inner shaft alone, and the forward and reverse rotation of the outer shaft alone can be achieved. The maximum operating speed of the inner and outer dual rotors under low load can reach 3700RPM, which has covered the full speed operating range of the actual propeller fan engine. Based on the present invention, the fault diagnosis analysis of the dual rotor structure of related aircraft engines, the equipment health operation and maintenance method and the vibration active control strategy research can be widely carried out.

Description

Technical Field

[0001] The present invention provides a simulation test bench device for analyzing the vibration characteristics of a propeller-fan coaxial counter-rotating structure, which specifically belongs to the field of research on the vibration transmission law and dynamic characteristics of a coaxial counter-rotating dual-rotor structure, and mainly conducts research on vibration transmission and coupling decoupling analysis for coaxial counter-rotating / corotating and single-axis forward and reverse rotor systems. The present invention designs a dual-rotor measurement and control test bench that can simulate a certain type of propeller-fan engine, and is used for dynamic simulation of the coupled vibration law of dual propellers, vibration signal identification, and dynamic balancing test verification. Background Art

[0002] The propfan engine is a high-subsonic, long-range, high-thrust-to-weight ratio high-thrust engine between turboprop and turbofan engines. It has the outstanding advantages of fuel saving and high propulsion efficiency. It consumes 20-30% less fuel than jet transport aircraft of the same level, while the flight speed is still 800 kilometers per hour, close to jet transport aircraft. It is the development direction of engines for future strategic transport aircraft and long-range bombers. In addition, the blade structure of the propfan engine is mainly double-row counter-rotating. The outstanding problem at present is that the vibration and noise are relatively large. The conventional dynamic balancing method is aimed at the single-rotor single-row propeller structure. European and American countries have started to carry out research on propfan engines since the 1970s, mainly focusing on improving the bypass ratio, increasing the blade speed, and reducing weight. It is urgent to carry out simultaneous research on strategies and methods to reduce the vibration and noise of the coaxial counter-rotating double rotor structure of the propfan engine.

[0003] The propfan engine is the heart of military aircraft. The vibration problem of my country's military aviation engines is very prominent. The causal relationship of its failure is intricate and complicated, which is a bottleneck that plagues the production, use, design and development of a new generation of engines. Tracking foreign technical data, it is found that foreign airlines such as Rolls-Royce, Airbus, and Boeing began to study propfan engines in the 1980s. From 2011 to 2016, Rolls-Royce had 8 patents related to propfan engines, 7 related patents from 2014 to 2016 for Airbus, and 3 related patents from 2014 to 2017 for Boeing. The United States has published a patent for automatic balancing of propfan engines since 2015 and has carried out relevant research. At present, the automatic balancing technology of aviation propellers has been installed and applied abroad. The single propeller automatic balancing system was officially installed on the C130 transport aircraft in the United States in 2014. It can reduce the rotor vibration of the engine blade end by more than 90%, and has formed a technical data report of a certain scale, carried out research on foreign technical progress and applications, and fully grasped the application status of automatic balancing technology, which provides a theoretical basis for the automatic balancing technology of propellers in my country's aviation field.

[0004] Since the early 1990s, research on machine tool vibration has begun in China, but there has been no report on industrial application. In 2015, domestic research institutions began to conduct preliminary research on control algorithms and actuators for dynamic balancing technology for single-row propellers, and achieved certain beneficial results in the laboratory stage, verifying the automatic balancing effect. There are no research reports on the automatic balancing technology of aviation propellers from other institutions in China, and there is a lack of research on the design of test devices for the coaxial counter-rotating dual-rotor structure of propellers. The existing single-rotor simulation test bench for turboprop aircraft cannot match the vibration transmission law research and dynamic characteristics analysis required by the current dual-rotor structure. In addition, other domestic research institutions have also carried out preliminary research on propeller fan engines for long-range transport / bomber aircraft, built relevant simulation test benches and carried out dynamic analysis to explore the vibration mechanism of propeller fan engines. The development trend of research on the dynamics and vibration characteristics of aviation propellers has already transitioned from single rotors to dual rotors.

[0005] The present invention proposes a simulation test bench device for analyzing the vibration characteristics of the coaxial counter-rotating structure of a propeller fan. Benchmarking a certain type of existing propeller fan engine entity, analyzing and studying its internal structural characteristics, power transmission mode and material characteristics, carrying out targeted mechanical structure design work, to the greatest extent possible to achieve similarity with the real machine structure, material consistency, and power characteristics matching, to provide hardware support and guarantee for subsequent related vibration characteristics test tests. The main body of this test bench is assembled from two servo motors, an inner rotor, an outer rotor, front and rear bearing brackets, synchronous belts and pulleys, a test weight plate, a simulated propeller and other parts. Combined with the independently developed dual-rotor motor drive control program and vibration detection system, it can realize the real-time extraction of vibration values ​​at typical positions of the simulation test bench under multiple working conditions (dual rotors coaxially rotating, dual rotors coaxially counter-rotating, single rotor inner shaft forward and reverse rotation, single rotor outer shaft forward and reverse rotation), explore the vibration coupling law of the dual-rotor system, and the specific test method and test process can reproduce and eliminate the contingency of the test to ensure the accuracy, reliability and consistency of the results.

[0006] In 2013, patent CN103308313A disclosed a basic motion aircraft engine dual-rotor system model test bench. The basic components of this patented technology mainly include a turntable base, synchronously rotatable transmission shafts A and B, and a basic turntable. Infrared optical sensors and eddy current sensors are provided on the inner and outer rotors to detect the vibration signals of the system. Compared with this patent, the difference is that the inner and outer shaft transmission mode of this patent is independently controllable and can be adjusted separately according to different test contents. In addition, the vibration measurement points of this patented technology are freely arranged, and the installation position of the vibration measurement points can be selected according to actual needs, and the vibration detection position is relatively flexible.

[0007] In 2015, patent CN204705483U disclosed an experimental platform for studying the dynamic characteristics of dual rotors of aircraft engines. The main structure of the device in this patented technology includes inner and outer rotors, a fixture, a pulley, two motors, a bearing seat, a base and a protective cover. It can reflect the true dynamic situation of the high and low pressure dual rotor system of the aircraft engine under maneuvering flight conditions, and the overall structure is relatively simple. Compared with this patent, the difference is that the internal and external motor drive of this patented technology is controlled by the host computer program, which can realize the customized output of the dual rotor speed, and the control method is more active and advanced.

[0008] In 2018, patent CN109406152A disclosed an experimental platform for the dynamic characteristics of aero-engine counter-rotating twin rotors. This patented technology can realize the experimental study of the dynamic characteristics of counter-rotating twin rotors and casing dynamic characteristics under coupling boundary conditions such as elastic support, squeeze film damper, and sealed airflow excitation. The device consists of a counter-rotating twin rotor test bench body, a high-pressure air system, a lubricating oil system, and a measurement and control system. The counter-rotating twin rotor test bench body is the core part of the experimental platform. Compared with this patent, the difference is that: this patented technology does not include a structural damping part and an elastic support, and both the inner and outer rotors are rigidly supported rotors and the operating speed is below the critical speed. The overall mechanical structure of this device is relatively compact and has strong operating stability. Furthermore, the outer rotor is transmitted power and torque by the second drive motor through a synchronous belt and a pulley. Compared with the transmission of two motors and two sets of couplings, the device has a richer power source and has stronger flexibility in the study of special problems.

[0009] Other related patents include: Patent No. CN105571867A, an aircraft engine vibration control test platform; Patent No. CN112629840A, an aircraft engine rotor-support-casing tester and its test method; Patent No. CN113109054A, a turboshaft engine whole machine dynamics dual-rotor test bench; Patent No. CN207336013U, dual-rotor system coupling misalignment simulation device, etc. Through the research and analysis of the existing patent technology data in the field of counter-rotating dual-rotor test platforms, different dual-rotor counter-rotating test benches have their own advantages and innovations. It can be found from the disclosed patent technologies that the main mechanical structure components of the test bench in the field of counter-rotating dual rotors are similar. Most of them are two motors driving the inner and outer main shafts, and some necessary components are matched to finally realize the counter-rotation and co-rotation of the two rotors. The difference lies in the different details of the design. The vibration characteristics analysis and control test bench for the dual-rotor structure of a propeller-fan engine, which is designed, proposed, processed and assembled by the present invention, has not only a main body with similar structure, but also independently developed a drive motor control program and an interactive interface with the host computer software, which can realize the free control and steering setting of the inner and outer shaft motor speeds, and the active control has a high degree of automation. More preferably, the mechanical structure design provides a clear design idea and technical reserve for the entire process from the perspective of solving practical engineering problems, shortens the device development cycle, reduces manufacturing costs, and fills a series of technical gaps in the ground simulation test bench for aviation engine vibration exceeding standard faults, such as source diagnosis and law exploration. Summary of the invention

[0010] The purpose of the present invention is to propose a simulation test bench for analyzing the vibration characteristics of a coaxial counter-rotating propeller-fan structure, which is used to carry out targeted diagnostic analysis and experimental research on the dynamic characteristics of a dual-rotor structure and the source tracing of vibration faults.

[0011] The technical solution adopted by the present invention is a simulation test bench device for analyzing the vibration characteristics of the coaxial counter-rotating structure of a propeller fan, which mainly includes an inner rotor drive motor, an outer rotor drive motor, a motor bracket, a synchronous belt and pulley, an inner and outer rotor, an inner and outer rotor test weight plate, a front propeller, a rear propeller, a tensioning wheel, a front and rear bearing bracket, a base, a bracket adjustment block and other components. First, place the test bench base, bolt the front and rear bearing brackets to the base, and install the inner and outer rotors through the bearings. Secondly, install the motor bracket on the rear bearing bracket and the inner rotor drive motor at the same time, install the synchronous belt and pulley on the outer rotor shaft end and connect them to the outer rotor drive motor at the same time, and tighten the tensioning wheel to the synchronous belt to avoid power transmission loss. Finally, install the rear propeller and the outer rotor test weight plate on the outer rotor, and install the front propeller and the inner rotor test weight plate on the inner rotor, and the test bench connection is completed. A programmable controller (PLC) is used as the power output control module of the inner and outer rotor drive motors. The controller is connected to the servo motor driver of the inner and outer rotor drive motors. The speed and direction control of the inner and outer rotor drive motors are realized on the computer side through the host computer program interface, which creates convenient conditions for carrying out related vibration characteristic tests.

[0012] The inner and outer shaft double rotor power output mode design. The present invention adopts the control mode of pulse plus direction of two servo motors to realize the transmission of power torque. The rotation of the inner rotor transmits power through the diaphragm coupling connecting the power shaft at the output end of the inner rotor driving motor and the inner rotor shaft end. The inner rotor driving motor is installed on the U-shaped motor bracket. At the same time, the entire U-shaped motor frame is pre-tightened and installed on the rear bearing bracket. The inner shaft bearing position passes through the deep groove ball bearing in the U-shaped motor frame and is connected to the diaphragm coupling. At this time, the power transmission chain of the entire inner shaft is installed. The transmission drive mode of the outer shaft is a connection scheme of synchronous belt plus synchronous pulley. The synchronous pulley is installed at the shaft end of the outer shaft, and the matching synchronous pulley is installed at the end of the outer rotor driving motor. Finally, the synchronous belt and the tensioning wheel device are installed. The motor rotates through the precise power transmission of the synchronous pulley and the synchronous belt, and the output torque acts on the outer rotor, and finally the free forward and reverse rotation of the outer rotor is realized. The design of the tensioning wheel reduces the gap of the synchronous belt during operation, greatly reduces the working flutter of the synchronous belt, improves the stability of the synchronous belt, and avoids the driving motor from stopping due to overload alarm.

[0013] The support adjustment block structure. Figure 218, 19, and 20 are the front row bearing bracket adjustment block, the rear row bearing bracket adjustment block, and the outer rotor drive motor bracket adjustment block, all of which are made of ordinary carbon steel. The three core load-bearing components of this test bench are the front and rear row bearing brackets and the outer rotor drive motor bracket. The installation accuracy of these three components determines whether the entire test bench operates smoothly and normally. The bracket adjustment block is first installed on the test bench base by bolts to fix the body, and then the adjustment screw is installed. The screw is screwed into the threaded hole on the side end face of the adjustment block until it supports the bottom end face of each bracket. Finally, the adjustment screw is tightened according to the actual assembly situation to achieve the purpose of adjusting the left and right parallel position of the bracket. Keep each bracket at the same height and level to ensure the installation coaxiality of the inner and outer rotors, and avoid the accuracy of the test results affected by the large double frequency caused by misalignment during the test process.

[0014] The inner and outer rotors are supported by an intermediate bearing. In order to meet the independent rotation requirements of the inner and outer dual rotor structure of the test bench, an innovative dual intermediate bearing support scheme is adopted to ensure that the inner and outer rings of the bearings can rotate independently. The specific installation method is: the inner rings of the two intermediate bearings (deep groove ball rolling bearings, cylindrical roller bearings) are respectively mounted on the end faces of the inner shaft bearings, and the tightening hexagonal bolts are screwed in to position the inner rings of the bearings. At this time, the inner shaft rotor is mounted together with the two intermediate bearings inside the outer shaft rotor, and the outer rings of the two intermediate bearings are simultaneously embedded in the bearing mounting end faces of the outer shaft. Finally, the intermediate bearing end cover of the outer shaft is installed to position the outer ring of the bearing, and the dual rotor structure is installed. Through the intervention of the support stiffness of the two intermediate bearings and the torque input of the drive motor, the four power output modes of coaxial counter-rotation, coaxial co-rotation, single-axis forward and reverse rotation of the outer rotor, and single-axis forward and reverse rotation of the inner rotor can be realized through the program control of the upper computer.

[0015] The inner and outer rotor test weight plate structure. Figure 2 As shown in Figures 9 and 13, they are the outer shaft test weight plate and the inner shaft test weight plate, respectively. The outer shaft test weight plate is connected to the outer shaft with bolts, and the inner shaft test weight plate is connected to the inner shaft with a tightening sleeve. Both plates are made of super-hard aluminum and are treated with a blackened surface chemical treatment. This structure is mainly used to add counterweight screws. A circle of threaded holes is machined on the periphery of the test weight plate to install the test weight screws to produce eccentric mass, thereby causing the dual-rotor system to produce fundamental frequency vibration due to mass imbalance. By installing screw counterweights of different masses on different test weight plates, the vibration response generated by each measuring point system of the test bench is different. This structure is used to explore the dynamic characteristics and complex coupled vibration transmission laws of the dual-rotor test bench, and carry out experimental verification.

[0016] The inner and outer rotor drive servo motor control system innovatively adopts a programmable controller (PLC) as the core control component to control the start and stop, speed and rotation direction of the dual-rotor structure, independently develops the upper and lower computer control programs, and designs the human-computer interaction software UI interface to realize real-time data communication between the upper computer and the lower computer PLC. Compared with the traditional servo motor driver to control the motor movement, this method of control is simpler, more convenient, and easier to operate, and can meet a variety of test conditions and operating parameters. In addition, for high-speed tests, the inner and outer rotor drive motors can be controlled at a location far away from the test bench, which significantly improves the safety of the test process. Figure 5 The software functions mainly include: independent enabling setting of internal and external axes, operation stop, time interval speed increase control (step speed), dual-axis co-rotation and counter-rotation control, and dual-axis step speed setting.

[0017] Compared with the prior art, the design of a simulation test bench for analyzing the vibration characteristics of a propeller-fan coaxial counter-rotating structure of the present invention has the following beneficial effects:

[0018] 1. The self-designed dual-rotor shaft power transmission scheme and the output mode of coupling plus synchronous pulley not only meet the basic functional requirements of dual-rotor rotation but also save installation space to a great extent, making the structure of the simulated propfan engine dual-rotor test bench more compact and improving transmission efficiency and transmission accuracy. In addition, the assembly process is more concise and efficient, and the overall reliability is higher.

[0019] 2. The design of double intermediate bearings can meet the independent and free rotation of the inner and outer rotors, such as Figure 3 As shown in Figures 28 and 29, the counter-rotating structure of an actual propfan engine is simulated to the maximum extent. The outer rotor is mounted on the outside of the inner rotor through the support stiffness provided by the intermediate bearing, and its axial displacement freedom is limited by the precise positioning of the inner and outer rings of the bearing, making the matching method more stable and reliable.

[0020] 3. Design of the bracket adjustment block and the inner and outer shaft test weight plate. The bracket adjustment block can be installed to adjust the coaxiality of the rotor test bench, solve the problem of axis misalignment during the installation process, greatly shorten the assembly time, and improve the installation efficiency; the innovative design of the inner and outer shaft test weight plate can flexibly and conveniently add artificial counterweights during the test process, change the mass distribution of the entire dual-rotor system and generate vibration response, which is convenient for conducting dynamic vibration characteristic test research under complex working conditions.

[0021] 4. Inner and outer rotor servo motor drive control system. The lower computer programmable controller PLC equipped with independent program development is used as the control center, and the control method is more effective and stable. At the same time, the upper computer (PC computer) human-computer interaction software interface is developed to achieve real-time communication and data transmission between the upper and lower computers, so that the speed and rotation direction of the coaxial dual rotors can be accurately set and controlled. In addition, the upper computer's motor drive remote control greatly improves the safety of the test. The operator can control the test speed away from the test bench and avoid close contact with the high-speed rotating tester, which greatly guarantees the safety of personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a three-dimensional design drawing of a simulated propeller fan dual-rotor test bench;

[0023] Figure 2 It is a diagram illustrating the structure of the components of the simulated dual-rotor test bench;

[0024] Figure 3 It is a two-dimensional design and processing drawing of a dual-rotor simulation test bench;

[0025] Figure 4 It is the three-dimensional structure three-view drawing of the dual-rotor simulation test bench;

[0026] Figure 5 It is a schematic diagram of simulating the vibration test of the actual double-rotor structure.

[0027] Figure number notes: Figure 2 1-test bench protective cover, 2-inner rotor drive motor, 3-outer rotor drive motor, 4-test bench base, 5-U-type motor frame, 6-diaphragm coupling, 7-deep groove ball bearing, 8-inner rotor shaft, 9-outer rotor test weight plate, 10-outer rotor simulated propeller, 11-outer rotor shaft, 12-outer rotor bearing end cover, 13-inner rotor test weight plate, 14-inner rotor simulated propeller, 15-expansion sleeve, 16-front bearing bracket, 17-deep groove ball bearing, 18-front bearing bracket adjustment block, 19-rear bearing bracket adjustment block, 20-outer rotor motor bracket adjustment block, 21-elastic retaining ring, 22-outer rotor motor bracket, 23-rear bearing bracket, 24-motor end pulley, 25-synchronous belt, 26-synchronous belt tensioning wheel, 27-outer rotor pulley; Figure 3 28-deep groove ball intermediate bearing, 29-cylindrical roller intermediate bearing. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings.

[0029] Example 1: Taking the coaxial co-rotation and coaxial counter-rotation vibration test of the propeller fan engine dual-rotor test bench as an example, the mechanical structure installation and coordination relationship of the dual-rotor test bench, the speed and steering control form of the inner and outer dual-rotor, and the specific functions of the inner and outer dual-rotor drive motor control software are specifically described. Figure 2 The mechanical components of the test bench shown in the figure are assembled into the main body of the dual-rotor test bench. The four bearings are installed in place. The synchronous pulley and the main shaft are connected by a flat key to transmit torsional stiffness and torque. Check whether the expansion sleeve connection between the front propeller and the inner rotor is tight and reliable. Check whether the two ends of the diaphragm coupling are tightly connected to the output end of the inner shaft motor and the power end of the inner rotor. Finally, check whether all threaded fasteners of the dual-rotor simulation test bench are pre-tightened and not loose. At this point, the mechanical hardware structure of the test bench is installed in place. In addition, it is necessary to check that the power lines and signal control lines of the drive motors of the inner and outer rotors are installed correctly, the servo motor driver is powered on, the programmable controller (PLC) is powered on, the host control computer is powered on and the control software is opened, and the serial communication line is connected to the PLC to establish a data transmission channel. The installation of the actual object and the drive motor control software interface are as follows Figure 5 As shown, enter the test target speed in the inner and outer shaft speed text boxes, set the rotation direction of the inner and outer shafts (forward / reverse), click Dual Axis Enable, and the inner and outer shafts will be automatically locked. Click Dual Axis Run again, and the inner and outer shafts will slowly accelerate at the same time according to the given speed and direction until they reach the set value and stabilize. Finally, click Dual Axis Stop, and the dual rotor drive motor brake unit intervenes to reduce the speed. Regarding the dynamic vibration characteristic test, use the following Figure 5 The eddy current displacement sensor shown is placed horizontally on the surface of the inner and outer shafts. By adding screw counterweights to the inner and outer shaft test weight plates to produce eccentric mass and thus an unbalanced vibration response, the coupling and transmission laws of the complex vibration of a certain type of propfan engine simulating a dual-rotor structure are explored.

[0030] Example 2: Taking the simulation of the single-axis forward and reverse vibration test of the dual-rotor test bench of a propeller fan engine as an example, the installation and coordination relationship of the mechanical structure of the whole machine, the rotor speed and steering control form, and the independent action mode of the inner and outer rotor drive motor control software are specifically explained. The installation and debugging of the dual-rotor simulation test bench hardware and software are the same as in Example 1, so it will not be repeated. In the upper computer control interface, only the target speed and direction of the inner or outer shaft are given. By setting the enable, run and stop of a rotor separately, the independent control of the inner rotor or outer rotor can be achieved, which is of great significance for exploring the vibration response and dynamic characteristics of a single rotor. In addition, the starting speed, final speed, interval time, and interval speed can be set to meet the test requirements of the rotor step speed. The dual-rotor speed control is relatively flexible and changeable as a whole, and the test process has strong adaptability to different working conditions.

Claims

1. A simulation test bench for analyzing the vibration characteristics of a propeller-fan coaxial counter-rotating structure, characterized in that: It includes an inner rotor drive motor, an outer rotor drive motor, a motor bracket, a synchronous belt and pulley, an inner and outer rotor, an inner and outer rotor test weight disk, a front row propeller, a rear row propeller, a tensioning wheel, a front and rear bearing bracket, a base, and a bracket adjustment block; the front and rear bearing brackets are bolted and installed on the base, and the inner and outer rotors are installed through the bearings; the motor bracket is installed on the rear bearing bracket and the inner rotor drive motor is installed at the same time, the outer rotor shaft end is installed with a synchronous belt and a pulley and is connected to the outer rotor drive motor at the same time, and the tensioning wheel is tightened against the synchronous belt to avoid power transmission loss; the rear row propeller and the outer rotor test weight disk are installed on the outer rotor, and the front row propeller and the inner rotor test weight disk are installed on the inner rotor, and the test bench connection is completed; a programmable controller PLC is used as a power output control module for the inner and outer rotor drive motor, and the programmable controller PLC is connected to the inner and outer rotor drive motor The servo motor driver is connected, and the speed and direction control of the inner and outer rotor drive motors on the computer side is realized through the upper computer program interface; the power output of the inner and outer rotors adopts the pulse plus direction control mode of two servo motors to realize the transmission of power torque, and the rotation of the inner rotor is transmitted through the diaphragm coupling connecting the power shaft at the output end of the inner rotor drive motor and the inner rotor shaft end. The inner rotor drive motor is installed on the U-shaped motor bracket, and the entire U-shaped motor frame is installed on the rear bearing bracket by bolt pre-tightening, and the inner shaft bearing position passes through the deep groove ball bearing in the U-shaped motor frame and is connected to the diaphragm coupling; the power transmission chain of the entire inner shaft is installed; the transmission drive mode of the outer shaft is a connection of a synchronous belt and a synchronous pulley, a synchronous pulley is installed at the shaft end of the outer shaft, a matching synchronous pulley is installed at the end of the outer rotor drive motor, and a synchronous belt and a tensioning wheel device are installed; The motor rotates through the precise power transmission of the synchronous pulley and the synchronous belt, and the output torque acts on the outer rotor, which can rotate freely forward and backward; the bracket adjustment block structure includes the front bearing bracket adjustment block, the rear bearing bracket adjustment block and the outer rotor drive motor bracket adjustment block, and the material is made of ordinary carbon steel; the three core load-bearing components of the test bench are the front and rear bearing brackets and the outer rotor drive motor bracket; the bracket adjustment block is installed on the base of the test bench by bolts to realize the fixed installation adjustment screw of the body, and the screw is screwed into the threaded hole on the side end face of the adjustment block until it supports the bottom end face of each bracket. The adjustment screw is loosened or tightened according to the actual assembly situation to achieve the purpose of adjusting the left and right parallel position of the bracket; the inner and outer rotors adopt the support structure of the intermediate bearing; the two intermediate bearing inner rings are respectively mounted on the end face of the inner shaft bearing, and the tightening hexagonal bolts are screwed in at the same time to realize the positioning of the bearing inner ring; the inner shaft rotor together with the two intermediate bearings The intermediate bearings are installed together inside the outer shaft rotor, and the outer rings of the two intermediate bearings are embedded in the bearing mounting end surface of the outer shaft at the same time. The intermediate bearing end cover of the outer shaft is installed to realize the positioning of the outer ring of the bearing, and the dual rotor structure is installed; through the intervention of the support stiffness of the two intermediate bearings and the torque input of the external drive motor, the four power output modes of the dual rotors, namely, coaxial counter-rotation, coaxial co-rotation, single-axis forward and reverse rotation of the outer rotor, and single-axis forward and reverse rotation of the inner rotor, are realized through the program control of the upper computer; the inner and outer rotor test weight disk structures are respectively an outer shaft test weight disk and an inner shaft test weight disk, the outer shaft test weight disk is connected to the outer shaft by bolts, and the inner shaft test weight disk is connected to the inner shaft by a tightening sleeve, and the double disks are made of super-hard aluminum and are treated by blackening the surface chemically; a circle of threaded holes is processed on the periphery of the test weight disk to install the test weight screws to produce eccentric mass, so that the dual rotor system produces fundamental frequency vibration due to mass imbalance; screw counterweights of different masses are installed on different test weight disks; The inner and outer rotor drive servo motor control system uses a programmable controller PLC as the core control component for the start and stop, speed and rotation direction control of the dual rotor structure, independently develops the upper and lower computer control programs and designs the human-computer interaction software UI interface to achieve real-time data communication between the upper computer and the lower computer PLC; The human-computer interaction software UI interface includes: independent enabling setting of internal and external axes, operation stop, time interval speed increase control, dual-axis co-rotation and counter-rotation control, and dual-axis step speed setting.

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