Measurement of pressure fluctuations and rotor movements in a volumetric pump

V diplomski nalogi smo obravnavali delovanje volumetričnih oziroma TMC črpalk. Z namenom razložiti razmere na izstopu iz črpalke smo primerjali črpalko brez modificiranega zoba, s črpalkami z različno modificiranimi zobmi. Z merjenjem karakteristike in fluktuacij tlaka na izstopu smo razložili delovanje črpalk, ki imajo nemodificiran, delno modificiran in močno modificiran en zob črpalnega rotorja. Karakteristike črpalk smo izmerili za različne vrtilne frekvence in modifikacije črpalnega rotorja. Fluktuacije tlaka na izstopu iz črpalke smo povezali z modifikacijami ozobja in ugotovili, kako notranje puščanje vpliva na fluktuacije tlaka. Fluktuacije tlaka se v času iznihavajo neodvisno od vrtilne frekvence rotorja in so posledica lastnosti merilnega mesta na izstopu iz črpalke. Z merjenjem napetosti na Hallovem zaznavalu smo izmerili aksialne pomike rotorja elektromotorja. Ugotovili smo, da je pri visokih delovnih tlakih črpalke rotor elektromotorja pomaknjen nižje proti črpalnemu rotorju kot pri nizkih delovnih tlakih. Izvedli smo tudi umeritev Hallovega zaznavala.This thesis discusses the operation of volumetric TMC pumps. To explain the flow properties on the pump output, we compared the pump with unmodified runner, with pumps with differently modified runner. With measurements of charateristic curves and pressure fluctuations on the pump outlet, we explained the operation of pumps with unmodified, partly modified and fully modified single vane of the pump runner. Characteristic curves were measured for different rotating frequencies and modifications of the pump runner. We related the pressure fluctuations on the pump outlet to the modifications of the pump runner vane and found out how the internal leakage influences the pressure fluctuations. Pressure fluctuations were independent of rotating frequency of the runner and were generated as a consequence of properties of the flow at the pump outlet. By measuring the voltage of the Hall sensor we measured the axial movements of the motor rotor. We found out, that the motor rotor was shifted towards the pump runner in the case of high operating pressure. Calibration of Hall sensor was also performed