| The plastic gear system must not only meet the requirements of the power transmission,but also must meet the low noise design.Plastic gears at this stage are generally based on the design standards of metal gears,and the overall design of the gear system must be continuously optimized to achieve high.quality operation of the plastic gear system.As an emerging industry,plastic gears currently have little research literature on the noise of plastic gear boxes.Therefore,in.depth study of the transmission noise of plastic gearbox will help to provide reference and reference for its optimized design.This paper discusses and analyzes the transmission of the gear system from the aspects of gear pair dynamics transmission analysis,coincidence degree theoretical analysis,modal analysis and harmonious response analysis.It uses a combination of experiment and simulation to gain an in.depth understanding of the plastic worm helical gear transmission system and the fourth stage.The noise generating mechanism and cause of the plastic transmission gear system,and put forward a reasonable noise reduction plan,through the experiment to know the actual noise reduction range.The main contents are as follows:(1)First of all,the worm helical gear and the four-stage cylindrical gear system were dynamically analyzed in the ADAMS software,and it was obtained that the meshing force of each gear pair showed a periodic change of unequal amplitude,and the gear shaft acted on the gear box.The force is also declining step by step.It not only presents the meshing state of the cylindrical gear,but also verifies the conclusion of the worm helical gear pair meshing transmission equation,indicating that the worm helical gear pair meshing is a point-contact curve motion in space without double meshing,which belongs to "local conjugate" Mesh.(2)The gearbox modal analysis and gear pair harmonic response analysis of the worm helical gear system were carried out.The sixth natural frequency of the gearbox was 7053.3Hz,which was the closest to the peak operating frequency of the gear pair,7500 Hz.Its mode contribution factor to noise is small,and the gear system is made of plastic parts with good damping characteristics,so the influence of resonance noise can be ignored.(3)For the noise problem of the worm helical gear box,find out its noise source by single factor elimination method,according to the principle of the coincidence degree of the worm helical gear pair.It is concluded that when the helical gear increases by 0.3 negative displacement,the gear pair coincidence is the most ideal,and the noise test experiment provesthat the operation of the gear system obviously becomes stable and the vibration noise becomes smaller.(4)For the four-level transmission plastic gear box with noise problems,through modal simulation and transmission noise test,it is found that the noise source is mainly the running noise of the motor and the first-level gear pair and the sound radiation resonance of the gear box shell.Then according to the modal analysis results and the principle of structural optimization,the head and tail of the gear box base with large natural vibration amplitude are optimized,and three effective structural noise reduction optimization schemes are proposed.Noise reduction effect. |
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