Abstract: The air gap of the integrated highspeed electric pump body is usually filled with power propulsion medium. When the rotor is running at high speed, the linear velocity on the rotor surface will stir the air gap fluid to rotate at high speed, causing turbulence in the small and narrow air gap, which affects the lubrication of the builtin bearings and rotor cooling of the motor body. This article took the fluid movement in the annular air gap of the highspeed electric pump motor with a rated speed of 40000 r/min as the background, and conducted numerical simulation research on the fluid flow pattern of Taylor Coulter flow in the air gap. Through numerical simulation analysis, it is found that as the rotor speed increases, the pressure difference between the inlet and outlet of the air gap increases, and as the air gap width increases, the pressure difference between the inlet and outlet of the air gap decreases. The data calculated in this article provides a theoretical reference for maintaining the inlet fluid parameters required for internal bearing lubrication and rotor cooling.

Key words: high speed shielded motor；air gap；Taylor Coulter flow；simulation analysis