TSE DPT60, Owner'S Manual

Page: 268 / 459

39
Series 90 Inspections and Adjustments
90000357
Rotate Neutral Adjusting
Screw
90000358
Tighten Neutral Adjusting
Screw Lock Nut
Variable Displacement Pump with Non-Linear Manual
Displacement Control
90000829
Non-Linear Manual Displacement Control
(MDC)
A centering spring, located on the control input shaft,
locates the control shaft in its “neutral” position. A bias
spring on the control spool maintains a force on the spool
and the control linkage to eliminate looseness (“free-
play”) in the linkage.
The “neutral” adjustment is the only adjustment that can
be made on the nonlinear manual displacement control.
All other functions are preset at the factory.
This adjustment must be made on a test stand or on the
vehicle/machine with the prime mover operating.
1. Install two 50 bar (or 1000 psi) gauges in each of the
displacement control cylinder gauge ports (M4 and
M5). Disconnect the external control linkage from the
control handle and make certain the control shaft is
in its “neutral” position. Start the prime mover and
operate at normal speed.
2. Loosen the lock nut on the neutral adjusting screw
with a 13 mm hex wrench.
3. Using a 4 mm internal hex wrench, rotate the neutral
adjusting screw clockwise until the pressure increases
on one of the pressure gauges. Note the angular
position of the wrench.
4. Rotate the adjusting screw counterclockwise until the
pressure increases by an equal amount on the other
gauge. Note the angular position of the wrench.
5. Rotate the adjusting screw clockwise half the dis-
tance between the locations noted above. The gauges
should read the same pressure (case pressure),
indicating that the control is in its “neutral” position.
6. Hold the adjusting screw stationary and tighten the
lock nut to 13.5 Nm (10 lbf•ft).
Do not overtorque
the nut.
7. Once the neutral position is set, stop the prime
mover, remove the gauges, and install the gauge
port plugs. Reconnect the external control linkage.
WARNING
The following procedure may require the vehicle/
machine to be disabled (wheels raised off the ground,
work function disconnected, etc.) while performing
the procedure in order to prevent injury to the
technician and bystanders. Take necessary safety
precautions before moving the vehicle/machine.
S000 007E