In terms of the problem that the unreasonable axial clearance worsens the working environment of the bearing, shortens the bearing life and affects the stable operation of the turbine pump ball bearing-rotor system, the axial clearance is introduced into the geometric analysis of the bearing components according to the mathematical relationship between the axial clearance and the contact angle; based on the Hertz contact theorem and the interaction between the components, the dynamic characteristics calculation model of the turbine pump ball bearing regarding the axial clearance is established. The variable reduction is carried out depending on the deformation geometric relationship between the components, thus simplifying the establishment process of the analytical formal stiffness matrix, and reducing the complexity of iterative calculation. With a certain type of turbine pump ball bearings taken as an example, the effects of axial clearance on contact load, stiffness and spin-roll ratio under different load conditions arc calculated and analyzed. The calculation results show that when the axial clearance increases, the contact load between the ball and the inner and outer raceways will decrease, the axial stiffness will increase, the radial stiffness will decrease, the spin-roll ratios of all balls will increase, and the difference between the spin-roll ratios of balls will also increase; the larger the radial force applied on the bearing is or the higher the rotational speed is, and the larger the axial clearance is, the more obviously the bearing stiffness and the spin-roll ratio will change with the change of external load. The maximum deviation of the established model and the typical dynamic examples is less than 2. 02%, and the overall deviation is low, which proves the effectiveness and stability of the established model in the calculation of bearing dynamic parameters. It also shows that the simplified measures taken in the numerical solution and the establishment of iterative matrixes are feasible. © 2023 Xi'an Jiaotong University. All rights reserved.
