The Effect of the Method of Compensation on Hydrostatic Bearing Stiffness

Abstract

Capillary, orifice, and flow control valve compensation of hydrostatic thrust bearings is investigated theoretically with regard to the effect of these three methods of compensation on the stiffness of the lubricant film. Equations are derived which permit rapid determination of bearing stiffness at any given load and film thickness. When a hydrostatic bearing is made to operate at any given film thickness and load, it is found that at this load and film thickness no adjustment of the compensating element or supply pressure will alter the fact that ψvalve > ψorifice > ψcapillary where ψ equals the absolute value of stiffness. Furthermore, with fixed supply pressure and compensation, this stiffness relationship will remain the same for all practical values of load above and below the initial film thickness-load point.

Influences of Lubricant Viscosity Ratio on Static Characteristics of Hydrostatic Thrust Bearing

“…However, according to Eqs. (9), (14) and (19) for the relationship between static stiffness K and r P , the stiffness is proportional to 1 …”

“…Malanoski and Loeb [1] studied hydrostatic bearings using capillary, orifice or flow control valve as the pressure compensation elements. They investigated the influences of these three compensated types on the film stiffness of hydrostatic bearings, and found the stiffness using flow control valve will be the greatest, followed by using orifice, then using capillary.…”

Identification of Characteristic Parameters for Hydrostatic Bearings

“…Raimondi and Boyd [1], Malanoski and Loeb [2], and Rippel [3,4] investigated the static characteristics and optimization of design parameters on hydrostatic bearing using three types of constant restrictors. Kang et al [5][6][7][8] investigated the static characteristics of open-type and closed-type planar bearings compensated by the constant compensations and variable restrictors to give that the bearing characteristics is determined by bearing design and the match of bearing and compensation.…”

Finite element method analysis of hydrostatic thrust pad bearings operating with electrically conducting lubricant

“…Lubricants used in the aforementioned studies [1][2][3][4][5][6] were assumed to be classical Newtonian fluid i.e. having linear relationship between shear stress and strain rate.…”