In addition to the shear damping base design, Slocum [1992] and Weldon [Hallum 1994] developed a self-compensating hydrostatic bearing design for use on their Model 1632 cylindrical grinder (Figure 15.16).
A gear pump (1) provides vibration-free fluid delivery to the self-compensating pads (2). The fluid enters the pad through ports at the edge of each and flows to collector grooves at the center that act as a feedback source for the bearing pads (3). There are two travel paths for the fluid (4): one from the lower self-compensating pad to the upper bearing pad and a similar one from the upper self — compensating pad to the lower bearing pad. As a load is applied over a compensation pad, the pad restricts fluid to the opposing bearing pad and, hence, directs additional fluid to the bearing pad opposing the load. The beauty of this system is that it is insensitive to manufacturing errors in the bearing gap and insensitive to dirt because there are no small-diameter passages. Typical port size is 3 mm. It even permits the use of low-viscosity water-based coolants as the fluid medium.
(1)
(3)
(4)
This type of slideway, supplied by New Way Machine Components Inc., has also been incorporated in machine design by Torrington’s Advance Machinery Center [Sotiropoulos 1998].