Design Of Three-dimensional Force Sensor Based On Measurement Of Axial Force And Radial Force Of Water Pump

The axial force and radial force of the pump are the main factors affecting its safe operation,which determines the overall performance of the pump.The real-time monitoring of the force of the pump shaft can provide an important basis for the design of the pump.In this paper,a three-dimensional force sensor was designed for the purpose of uncoupled measurement of axial force and radial force without changing the structural stability of the pump body.Firstly,the measurement methods of axial force and radial force were determined according to the internal working conditions of the water pump,the elastomer structure in line with the measurement method was proposed,the characteristics of different elastic elements were analyzed,the elastic elements of the sensor were designed,and the working principle of the sensor was determined;Secondly,the performance of the sensor elastomer structure was analyzed by finite element method,including the static analysis of static force and the dynamic analysis of dynamic force.The dynamic analysis mainly includes the harmonic response analysis and transient dynamic analysis based on modal analysis,so as to reflect the frequency domain characteristics and time domain characteristics of the sensor,and was used to verify the accuracy of virtual dynamic simulation based on the sensor.The size of the sensor elastomer structure was optimized.Taking high sensitivity,good dynamic characteristics and safe strength as the optimization index,the response surface optimization of the elastomer structure was carried out,the relationship between the size variables of the elastomer and the optimization index was analyzed,the constraints were added to the optimization index,and finally the optimal size was obtained.According to the optimized elastomer structure,the whole sensor was designed and manufactured.The sticking position of the strain gauge was determined by the path mapping method,and the measuring circuit of the sensor and the whole sensor measuring system were designed.The calibration experiment platform was designed,and the force calibration in different directions was realized through the change of the experimental platform.The sensor elastomer structure designed in this paper can greatly simplify the calibration process and realize operation decoupling.The least square method was used to fit the one-dimensional force data in three directions,complete the static calibration of the sensor,calculate the linearity and analyze the linearity error.