Research On Key Technology Of Low Noise Gear Pumps

The use of external gear pumps is affected by the shortcomings of excessive noise and cannot be used in occasions with high requirements for vibration and noise.Therefore,there is an urgent need to reduce the noise emitted by external gear pumps.The main content of this subject is to study the noise reduction of involute gear pumps,and analyze the unbalanced radial force as a structural noise source.A calculation formula for the instantaneous radial force based on the involute gear meshing characteristics and profile characteristics is proposed.Build a mathematical model,and then use mathematical models to analyze methods of reducing radial force.Finally,analyze the frequency domain distribution of radial force and the vibration shape of the gear shaft,and obtain a method to reduce the vibration.The specific research content is as follows:(1)Collect materials related to gear pump noise,clarify the current development trend of gear pumps,and conduct mathematical analysis on one of the key problems that cause gear pump structure noise,that is,radial unbalance force,in order to provide guidance on reducing the noise of gear pumps.(2)Analyze the unbalanced radial force of the gear pump,and derive the calculation formula of the instantaneous radial force on the driving gear and the driven gear based on the gear tooth profile and gear meshing characteristics,in preparation for the establishment of the mathematical model.(3)Establish a parameterized mathematical model of the gear instantaneous radial force,and use the mathematical model and finite element simulation to simulate the operation process of the gear pump.Compare the instantaneous radial force calculated twice.The relative error is about 5%,which proves the correctness of the mathematical model.(4)The influence of changing the size of the pressure cavity on the maximum radial force is discussed and the conclusion is drawn that expanding the range of the pressure cavity or transition zone can effectively reduce the maximum radial force of the gear pump.(5)The discrete Fourier transform algorithm is added to the mathematical model,and the influence of changing the size of the pressure cavity on the frequency domain characteristics of the radial force is discussed,and the conclusion is that the radial force of the gear pump is changed by changing the parameters of the pressure cavity of the gear pump.When it drops to the minimum value,fine-tuning the parameters of the high and low pressure cavity can greatly reduce the meshing frequency component of the radial force of the gear pump under the condition of increasing the radial force in a small range,so that the amplitude of the gear shaft is greatly reduced to achieve The purpose of reducing the structure noise of the gear pump.