Functional Description - Sauer Danfoss 51 Series Service Manual

Bent Axis Variable Displacement Motors

Functional Description

51000003
Fig. 10-2 - Loop
Flushing
Components
6
51000004
Fig. 10-3 - Loop
Flushing Defeat
Components
Loop Flushing
Series 51 motors used in closed circuit applications
incorporate an integral loop flushing valve as stan-
dard equipment. Installations that require additional
fluid to be removed from the main hydraulic circuit
because of fluid cooling requirements, or circuits
requiring the removal of excessive contamination
from the high pressure circuit, can benefit from loop
flushing. Series 51 motors used in open circuit appli-
cations may have the optional loop flushing defeat
components installed.
Series 51 motors equipped with an integral loop
flushing valve also include a charge pressure relief
valve. The setting of the motor charge relief valve
affects the function of the flushing circuit. Higher
motor charge relief settings reduce the loop flushing
flow and increase the flow over the pump charge
pressure relief valve when the circuit is operating.
Lower motor charge relief settings increase the loop
flushing flow and may increase the motor case pres-
sure when the circuit is operating.
An appropriate combination of pump and motor charge
pressure settings should be maintained to insure the
proper function of the loop flushing circuit. Correct
charge pressure must be maintained under all condi-
tions of operation to maintain pump control perfor-
mance in closed loop systems.
NOTE: An optional orifice may be installed between
the motor charge relief and the motor case to
limit the maximum flushing oil flow.
Series 51
10 - 2