Supplying fluids different in pressure from one end of a revolving shaft
without providing a diagonal hole in the revolving shaft for supply holes
for feeding hydraulic fluid and lubricating oil. The time for
manufacturing and the cost of providing a hydraulic fluid feeder to the
revolving shaft is reduced. A hydraulic fluid feeder includes a central
hole provided on the centerline of the revolving shaft. Hollow tubes
having a smaller outside diameter than the inside diameter of the central
hole are concentrically inserted into the central hole and the central
hole is partitioned. Either of the passages formed by partitioning
functions as a hydraulic fluid supply passage for the hydraulic equipment
and the other functions as a hydraulic fluid supply passage for another
piece of hydraulic equipment or a lubricating oil supply passage for a
bearing provided on the revolving shaft.