Mechanical Neutral Adjustment - Danfoss H1P 045 Service Manual

Service Manual
H1P 045/053/060/068 Axial Piston Single Pumps
Adjustments

Mechanical Neutral Adjustment

© Danfoss | June 2020
Mechanical neutral is set with the pump running at 1800 min
pump in each direction. The procedure is the same for each side of each pump for both the front and rear
sections.
You can do this with a small movement of the eccentric screw on EDC controls, however non-feedback
controls (NFPE/FNR) lack this mechanism. To stroke a pump with non-feedback control, you must provide
a 100 Hz PWM signal to the control solenoids. If you perform this adjustment with the pump installed in a
vehicle or machine, safely elevate the wheels or disconnect the mechanism to allow safe operation
during adjustment.
This procedure details setting neutral for the entire pump, one side at a time. Alternate M4/M5 and
MA/MB to zero out forward and reverse directions of the front unit, then move the gauges to M4/M5 of
the rear unit and MC/MD (system gauge ports for the rear unit). Refer to the drawing on the next page to
identify all ports. The front and rear sections are basically mirror images of each other. The control
solenoids C1 and C2 are marked on each control.
While performing this adjustment, you monitor the following pressures:
•
Servo pressure at M4 and M5
•
System pressure at MA and MB
•
Pressure differential between M4 and M5 (optional)
•
Pressure differential between A and B (optional)
Unintended Machine Movement
Unintended movement of the machine or mechanism may cause injury to the technician or bystanders.
Secure the machine or disable/disconnect the mechanism while servicing to protect against unintended
movement.
-1
(rpm). To set neutral, you must stroke the
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