Abstract: Sliding bearing is the key component of electronic water pump which directly affects the stability of the impeller rotor system.In order to establish a connection between the design and manufacturing factors with the vibration and noise performance of the pump assembly and reduce the vibration and noise effectively,finite element analysis and experimental research were conducted based on a low-power cantilever external rotor electronic water pump to explore the influence of sliding bearing parameters on the vibration and noise characteristics of the electronic water pump. The results showed that the magnitude of the water film stiffness of the sliding bearing affected the existence of the relative swing mode between the pump rotor and the core shaft. Compared with CF/PPS composite material bearing,graphite bearing electronic water pump effectively reduced the various harmonic components in the vibration spectrum and eliminated the frequency modulation sound of blades. Excessive eccentricity of the shaft neck could easily trigger the pump rotor-core shaft relative swing mode under low-speed conditions,leading to structural resonance and noise.Reducing the clearance of the bearing could greatly reduce the frequency vibration of the water pump blades under high-speed conditions,and suppress the structural noise of the rotor-core shaft relative swing mode.

Key words: sliding bearing, electronic water pump, vibration and noise