Analysis of the operation of a hydrostatic bearing in transition modes

Abstract

The design of reliable rotor supports for modern high-speed machines is associated with the solution of many complex problems, both theoretical and experimental. Experimental studies play an important role in the system of scientific research and allow improvement and refine mathematical models and the application of numerical methods for their implementation. Experimental studies are usually selective and therefore require careful preparation. The task was set to investigate the characteristics of a hydrostatic bearing in the starting and braking modes. A program of experimental studies of the behavior of a shaft on hydrostatic bearings for the most difficult operating conditions has been developed. The advantages of hydrostatic bearings are given compared with other types of plain bearings, as well as compared with rolling bearings. The effectiveness of hydrostatic bearings is shown, compared with other types of bearings, for modern high-speed machines, in which there is an increase in vibration overloads and vibration displacements. Hydrostatic bearings have proven themselves in all operating modes, including transient ones. A description of the experimental setup for the study of transient modes of operation of the shaft on hydrostatic bearings is given. Studies of the transient modes of operation of the shaft on hydrostatic bearings were conducted at various values of the pressure of the working fluid supply, residual unbalance, as well as various values of the diameter of the hydrostatic bearing. To identify the movement of the rotor on hydrostatic bearings, the values of the amplitudes of oscillations during stationary (steady) movement of the rotor are also presented. It is shown that the comparison of the oscillation amplitudes of the rotor on hydrostatic bearings with a diameter of 0.06 m for the cases of non-stationary and stationary modes of its operation during the acceleration of the amplitude of oscillations in the entire range of rotational speeds is slightly lower (by about 15…20 %) than in the case of a stationary mode of operation of the rotor. When the rotor slows down, the amplitude of the rotor oscillations at high speeds is somewhat larger (by about 7…9 %), and at low speeds it is less by 8…10 % than in the case of a stationary rotor operation. The small influence of the non-stationary nature of the rotor movement on the dynamic characteristics can be explained by its large mass.