MTS Series 248 Actuators - Manual (Page 19)

Hydrostatic Bearing Capillaries
Series 248 Actuator Product Information Introduction 19
Hydrostatic Bearing Capillaries
Capillaries providing hydraulic fluid to the hydrostatic bearing pads are found in
both the upper and lower end caps. The pressurized hydraulic fluid to the
capillaries is supplied by a separate (pilot pressure) line. Hydraulic flow through
the capillaries to the hydrostatic bearing pads can be checked without major
disassembly. It is necessary to check for excessive friction (which typically
shows up as a large differential pressure across the piston being required to move
the piston rod).
Static Support Assembly
A static support configuration supports a heavy component or fixture on the
actuator piston rod without using hydraulic pressure to offset the weight.
The static support assembly contains a nitrogen pressure vessel which is charged
with dry nitrogen. This pressurized nitrogen is ported to the static support
pedestal tube, where it pushes upward on the piston rod to support a heavy
component or fixture.
Static Support Assembly
Static
Support
Pedestal
Nitrogen
Pressure
Vessel