A high-pressure piston pump for a fuel system of an internal combustion engine,
includes a housing, a piston, which defines a working chamber, and drive shaft
having at least one crank section and supported in the housing by means of at least
one shaft bearing. A piston bearing supports the piston at least indirectly against
the crank section of the drive shaft. At least one of the bearings between parts
that move in relation to one another is a hydrostatic bearing connected to the
working chamber by means of a fluid connection. To increase efficiency, the fluid
connection between the working chamber and the hydrostatic bearing is provided
with a device operable to intermittently interrupt the fluid connection.
