Sauer Danfoss 40 Series - Control Options; External Control Handle Requirements

41
520L0635 • Rev EH • June 2009
Series 40 Axial Piston Pumps
Technical Information
Control options
The Direct Displacement Control (DDC) can be located on either side of a Series 40
- M25, M35, or M44 pump. It pro vides a simple, positive method of control. Movement
of the control shaft causes a propor tional swashplate movement, thus varying the
pump’s displacement from full displacement in one direction to full displacement in the
opposite direction.
Some applications (generally vehicle propel) re quire a provision for non-linear control
input to reduce control sensitivity near neutral. Damping or fric tional forces may be
necessary to produce desir able control feel.
Neutral position is not factory set, nor is there any internal neutral return mechanism. The
application must include provisions for all control linkage and neutral return fuctionality.
With no external forces applied to the swash plate trunnion, internal hydraulic forces may
not return the swashplate to the neutral position under all conditions of operation.
The DDC is available on variable pumps and tandem pumps.
External control handle requirements
Maximum allowable trunnion torque is 79.1 N•m [700 in•lbf] for M25, M35, and M44.
Minimum torque necessary to hold the swash plate at a zero angle for neutral is 2.3 N•m
[20 in•lbf]. Maximum trunnion angle is 15° for M25 and 16° for M35 and M44.
DIRECT DISPLACEMENT
CONTROL (DDC) M25,
M35/44 VARIABLE
PUMPS
DDC on Left Side of M35 Pump
100%
100%
CW
Trunnion rotation
CCW
Trunnion rotation
Pump
displacement
Pump
displacement
T101 306E
Pump Displacement vs Swashplate Rotation
Max torque Nm [in·lbf] 79.1 [700]
Min torque Nm [in·lbf] 2.3 [20]
Max angle M25: 15° M35/44: 16°
Input shaft rotation CW CCW
Trunnion location Right Left Right Left
Trunnion rotation CW CCW CW CCW CW CCW CW CCW
PV or front PV
Port A Flow Out In In Out In Out Out In
Fort B Flow In Out Out In Out In In Out
Rear PT
Port C (A) Fow In Out Out In Out In In Out
Port D (B) Flow Out In In Out In Out Out In
Trunnion
106 258
DDC input specs
Pump flow direction