Control Neutral Adjustment - Danfoss T90 Series Service Manual

Service Manual
Series T90 Axial Piston Pumps
Adjustments

Control Neutral Adjustment

34 | © Danfoss | March 2020
Frame size Lock nut wrench size and torque
055 13 mm 24 N•m [18 lbf•ft]
075 13 mm 24 N•m [18 lbf•ft]
100 13 mm 24 N•m [18 lbf•ft]
All functions of the Hugh Current Electric Displacement Control (HCEDC) are preset at the factory. Adjust
the pump to neutral with the pump running on a test stand or on the vehicle/machine with the prime
mover operating. If adjustment fails to give satisfactory results, you may need to replace the control or
Minor repair
coils. See for details.
W
Warning
Unintended movement of the machine or mechanism may cause injury to the technician or bystanders.
To protect against unintended movement, secure the machine or disable/disconnect the mechanism
while servicing.
1. Install a 50 bar [1000 psi] gauge in each of the two servo gauge ports (M4 and M5). Disconnect the
external control input (electrical connections) from the control. Start the prime mover and operate at
normal speed.
2. Use a 4mm internal hex wrench to hold the neutral adjusting screw (M015) stationary while loosening
the locknut (M060) with a 13mm wrench.
3. Observe pressure gauges. If necessary, turn adjusting screw (M015) to reduce any pressure
differential.
Adjustment of the HCEDC is very sensitive. Be sure to hold the hex wrench steady while loosening the
locknut. Total adjustment is less than 120 degrees.
Control adjustment
Servo pressure gauge port M
0 - 50 bar [0 - 1000 psi]
/16 in
19 N•m [14 lbf•ft]
4. Rotate the neutral adjusting screw (M015) clockwise until the pressure increases on the gauge. Note
the angular position of the wrench. Then rotate the neutral adjusting screw counter clockwise until
Adjusting
screw size
4 mm
4 mm
4 mm
Adjusting screw
4 mm
Approximate displacement change
per revolution of adjusting screw
4.2 cm³/rev [0.26 in³/rev]
5.1 cm³/rev [0.31 in³/rev]
6.2 cm³/rev [0.38 in³/rev]
Locknut
13 mm
12 N•m [9 lbf•ft]
Servo pressure gauge port M5
0 - 50 bar [0 - 1000 psi]
/16 in
19 N•m [14 lbf•ft]
P106 343E
AX216086485386en-000101