Control Response
H1 controls are available with optional control passage orifices to assist in matching the rate of
swashplate response to the application requirements (e.g. in the event of electrical failure). The time
required for the pump output flow to change from zero to full flow (acceleration) or full flow to zero
(deceleration) is a net function of spool porting, orifices, and charge pressure. A swashplate response
table is available for each frame indicating available swashplate response times. Testing should be
conducted to verify the proper orifice selection for the desired response.
H1 pumps are limited in mechanical orificing combinations. Mechanical servo orifices are to be used only
for fail-safe return to neutral in the event of an electrical failure.
Typical response times at the following conditions:
∆p
250 bar [3626 psi]
Viscosity and temperature
30 mm²/s [141 SUS] and 50 °C [122 °F]
Charge pressure
20 bar [290 psi]
Speed
1800 min
-1
(rpm)
EDC Response Time
Stroking direction
0.8 mm [0.03 in] orifice
1.3 mm [0.05 in] orifice
No orifice
Neutral to full flow
4.4 s
1.95 s
1.0 s
Full flow to neutral
2.9 s
1.3 s
0.8 s
Technical Information
H1 Axial Piston Single Pumps, Size 115/130
Control Options
©
Danfoss | May 2017
11063346 | BC00000198en-US0801 | 19
