This study presents the identification method of design parameters for single-action cylindrical spool-type restrictors of hydrostatic bearing. These parameters include restriction parameter, spool displacement parameter, and spring preload. The flow rates, inlet pressures, and outlet pressures are measured to be utilized for parameter identification of single-action cylindrical spool-type restrictors by using experimental equipment. This equipment-like an open-type planar hydrostatic bearing supports a worktable for changing recess pressure by changing apply load. Then, design parameters can be identified from the measurements of the inlet pressure, the recess pressure, average temperature, and the flow rate for each restrictor by using minimizing total error square between measured and identified quantities of flow rates. An identification method with experiments for single-action cylindrical spool-type restrictors of hydrostatic bearing is presented and designed. Also, the influences of design parameters on flow rate of single-action cylindrical spool-type restrictors are studied by experiments. The experimental equipment used in this study is our design, which can be used for all types of restrictors and hydrostatic bearings. This identification method for design parameters of the single-action cylindrical spool-type restrictors is reliable, valid, and accurate. The identification of design parameters is necessary for design change and calibration of single-action cylindrical spool-type.

This paper investigates how to evaluate the damping ratio in practical measurement for hydrostatic bearing which possesses overdamped damping. The traditional methods such as decayed response, band width of resonant peak, transient response of step excitation and hysteresis circle cannot be utilized for get over overdamped behavior. Because the fundamental mode of worktable supported by hydrostatic bearing is overdamped, high modes must be blended into or influenced by this mode. This paper uses the dimensionless frequency responses with damping ratio as parameter of single DOF mass-damper-spring model to generate a scale to evaluate the damping ratio of the fundamental mode from the experimental measurement of impact response. Using this scaling method, this paper has investigated the influences the operation and design parameters of pressure compensations in hydrostatic bearing on the damping performance.

The resonant peaks can be suppressed by damping, those effects is dependent on damping ratio of system. In this paper, we propose a scaling method to evaluate the damping ratio of hydrostatic bearings for the data from model test. This method fits specifically for the overdamping of all hydrostatic bearing. This is direct and the easiest method to obtain the damping characteristics of oil film for the lowest band before the first resonant peak. The frequency responses of acceleration per force for a single-degree-of-freedom mass-spring-damper model is used to generate the evaluation scales for the damping ratios of the modal test results of worktable mounting on hydrostatic bearing. The case study for experimental results of the impact response are evaluated for damping ratio of the hydrostatic film by these method. Furthermore, using this scaling method, the influences of three types of compensations on the damping ratio of a hydrostatic bearing are compared. The results reveal that the constant flow has the largest damping ratio, and the capillary restrictor has the smallest one.