Komatsu PC500LC-10R Shop Manual page 213

10 STRUCTURE AND FUNCTION
When servo piston is balanced
Suppose that the pressure receiving area on the large diameter piston side is (A1), that on the small diameter
piston side is (A0), and the pressure being transmitted to the large diameter piston side is (PEN).
1.
When main pump pressure (PP) of LS valve is balanced with the combined force of LS pressure (PLS) and
spring (4) and (A0) x (PP) = (A1) x (PEN), servo piston (12) stops at that position.
2.
The pump swash plate is held in an intermediate position. "It stops at the position where the opening of the
spool (6) from port (D) to port (E) and that from port (C) to port (D) are approximately equal."
3.
The relationship between the pressure receiving areas at both ends of servo piston (12) is (A0):(A1) = 3:5.
Under the balanced state, the ratio of the pressures applied to both ends is (PP): (PEN)C 5 : 3.
4.
The force of spring (4) is adjusted so that the balanced and stopped position of spool (6) is determined
when (PP) - (PLS) = 2.65 MPa 27 kg/cm
5.
When (PSIG) ["output pressure of LS-EPC valve, 0 to 2.9 MPa 30 kg/cm
anced position changes in the range of (PP) - (PLS) = 2.65 MPa {27 kg/cm
proportion to pressure (PSIG).
MAIN PUMP PC VALVE
PC
Abbreviation for Pressure Compensation
PC500LC-10R
COMPONENT PARTS OF HYDRAULIC SYSTEM
2
at the standard center.
AEP19356
2
"] is applied to port (G), the bal-
2
} to 1.18 MPa {12 kg/cm
2
} in
10-119