Upright SB60 Service & Parts Manual page 41

Test the actuator for proper operation and leakage prior
to securing the endcap with set screws. Mark the
relative position of endcap and housing and check the
marks periodically during the tests below to ensure that
the endcap does not back out. Apply pressure to the
actuator ports and check breakaway. The breakaway
should be about 200 PSI. Alternately apply pressure to
port on the opposite side of the piston and check for
axial movement. The axial movement should not
exceed .020". If the axial movement is excessive re-
tighten the end cap. Apply 3000 PSI pressure to one
port until piston bottoms out and the actuator rotation
stops. Remove non-pressurized hydraulic line and
check for internal and external leakage. Repeat leakage
test on opposite actuator port.
Install set screws (105) and stake to insure they will not
back out during actuator operation.
Bars indicate starting
positions of piston and
shaft. Arrows indicate
direction they will
rotate. The housing
with integral ring
gear remains
stationary.
Figure 3-26
SB60 Work Platform
Maintenance
As fluid pressure is applied,
the piston is displaced
axially while the helical
gearing causes the piston
and shaft to rotate simulta-
neously. The double helix
design compounds rotation:
shaft rotation is about twice
that of the piston.
Hydraulic Line Attachment
The hydraulic lines from the control valve to the actuator
should be as short as possible. If the lines hold more oil
than the actuator displaces, the oil is cycled back and
forth, and not allowed to flow to tank for filtering and
cooling, resulting in accelerated actuator wear.
Figure 3-27
Section
3.19
3-27