Daewoo Solar 225LC-V, Shop Manual

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S0708320
Page 10 Main Pump (With Regulator)
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OVERLOAD PROTECTION
Overload protection occurs automatically, in response to increased pressure on the piston (621) and
compensator rod (623). Whenever the discharge pressure of Pump 1 and Pump 2 (P1 and P2) are
increased beyond a certain point, the higher pressure acts on the piston and compensator rod (621 and
623), pushing both toward the right, until hydraulic pressure and the return force of the inner and outer
springs balance out. The feed-back lever assembly pivots around Point "D" and the spool (652) is pushed
toward the right, decreasing pump discharge to prevent engine overloading.
When discharge output of both pumps (P1 and P2) decreases, the compensator rod (623) is released,
moving the feedback lever assembly in response to the pressure of the inner and outer return springs. The
regulator "Cl" port is connected to the tank port. Discharge flow recovery results in an increase of
discharge flow.
REGULATOR ADJUSTMENT
Maximum and minimum discharge flow,
horsepower control characteristics and
discharge control characteristics can all be
modified by changing the position of adjustment
screws built into the pump housing (Figure 1)
and the end plate of the regulator valve (Figure
8).
Maximum and minimum discharge flow can be
modified by loosening lock nuts (808, Figure 1).
To decrease maximum discharge flow (by
approximately 5.6 lpm [0.025 gpm]), tighten
adjusting screw (954) by 1/4 turn. Figure 10
shows the effect of this adjustment on the output
characteristics of the pump.
To increase minimum discharge flow (also by
5.6 lpm [0.025 gpm]), tighten adjusting screw
(953) by 1/4 turn. Figure 11 shows the effect of
this adjustment on the output characteristics of
the pump.
NOTE: Other characteristics of
operation should not be
affected, when adjustments to
maximum or minimum
discharge flow are made, but
very large changes to the
adjustment position of either
adjustment screw could cause
changes in the maximum
discharge pressure, and require
a corresponding adjustment of
the main relief valve pressure
setting.
Q
P
HDA3008L
Figure 10
Q
P
HDA3009L
Figure 11