Research On Transmission And Fatigue Test Machine For Multi-layer Perforated Steel Strip

The multi-layer perforated steel belt has the advantages of no slip,constant transmission ratio,low lubrication requirements and no elongation after wear,and is especially suitable for agricultural machinery working in more complicated environments.However,the research on the operation and fatigue performance test device of this new type of structural transmission belt has not been reported yet.Therefore,in order to obtain the transmission and fatigue performance of this new type of structural belt,according to the force and power range of common agricultural machinery,for the user of the multi-layer perforated steel belt transmission system,a diameter and rotation speed for different pulleys are designed.Power,a test device that simulates the transmission and fatigue performance of a multi-layer steel strip under actual operating conditions.The main research contents and results are as follows:1.Based on the stress and transmission characteristics of the multi-layer perforated steel strip and gear teeth,the technical requirements that need to be met when designing the test device are analyzed,and the design scheme of the test device is finally determined.2.According to the transmission mode between the reel and the drum in the small combine harvester,combined with the transmission parameters required for actually harvesting the crop,the motor corresponding to the power is selected as the energy output of the test device.According to the test loading power,the load of each drive shaft is analyzed.It is found that the maximum torque value of the drive shaft is 48.10 N m and the working speed is 975r/min.It provides a reference for the design and manufacture of prototype components and the selection of sensors.3.A test device consisting of two parts,mechanical and control,was designed.The mechanical part has a power output of 5.5 kW,the driving wheel speed is up to 2800 r/min,the load torque range is 0~50 N m,the main driven wheel center distance range is adjustable from 150 to 1550 mm,and the test belt length is 2000 mm.When the device is working,the actual speed and load conditions of the steel belt transmission system during operation can be simulated by changing the belt diameter and the tooth type,different steel belt layers,hole type,size and other parameters.Under the normal working transmission performance,and the test under high speed conditions,to obtain the fatigue properties of the steel strip.4.Using the SolidWorks software to carry out three-dimensional modeling of the testdevice and stress analysis on the high-speed shaft.The analysis results show that the shaft end deflection of the high-speed shaft is 0.04 mm under the maximum torque,and the maximum stress generated by the shaft is in contact with the shaft and the key.The value of the part is 98.1 MPa,which is less than the fatigue limit stress of 218 MPa of the high-speed shaft 45 steel material,indicating that the design of the high-speed shaft fully meets the requirements of the test device.The vibration mode simulation analysis of the test equipment frame and the high speed shaft was carried out by using the finite element analysis software ANSYS.During the test,although the range of rotation speed required for the pulley was wide,the test time of the test belt and the pulley engagement performance was short,and the apparatus was insufficient for resonance.The first-order natural frequency of the high-speed shaft is 4501.7 Hz,and the maximum speed provided by the motor during the fatigue test,that is,the maximum speed of the high-speed shaft is only46.7 r/s,which is not enough to cause resonance.5.Designed the software and hardware system of the control part.Aiming at the high temperature generated by the steel belt during high-speed operation,a water spray cooling device controlled by a single-chip microcomputer was designed,and the electromagnetic relay was used to control the spraying amount of the boosting water pump.The booster pump is powered on every 2 minutes under the control of the stepper motor.Each time it is turned on for 5 seconds,the amount of water sprayed each time is 415 mL.The control program is written in C language,and the tension controller controls the current to control the magnetic powder amount of the magnetic powder clutch,thereby achieving a fast response and a stepless loading load mode.The resistance strain gauge was used and a program was designed to measure the preload of the steel strip,and the torque sensor acquisition program and the computer front panel were designed.The virtual instrument software LabVIEW was used to design the front and rear panels of the upper computer.The practicality of the human-computer interaction system was verified by experiments.6.Through the actual performance test of the multi-perforated steel strip,observe the vibration of the steel strip,the phenomenon of stripping and other abnormal working phenomena,and make a comparative test on the transmission performance of the flat belt.Fatigue performance test According to the temperature rise of different positions of steel strips and different cycle times,the energy released per unit area of ??the contact zone of the steel strip under steady state(about 12cal)is calculated.It can be concluded that the equivalent temperature of the thermal fatigue of the strip is The fatigue performance of the upper limit temperature(not the average temperature).The toothed meshing state was goodunder high speed conditions during the whole test,which proved the rationality of the design of the pulley and the perforation.