CONTROL GP-MACHINE 1648255 - Caterpillar

Illustration 2 g00461598
Spring Assembly (4) Barrel (9) Spring (17) Cup (18) ShimSpring (9) and shims (18) are held in place on the swashplate (8) by the cup (17). Spring force holds the face of the barrel (4) against the port plate (7) and the head (15) .The length of the stroke of pistons (10) is changed when the swashplate (8) is rotated about the axis.Main Relief Valve
The main relief valve is a cartridge type valve. The main relief valve provides two functions for the vibratory circuit.
The main relief valve limits the pressure.
The main relief valve acts as a makeup valve for the main loop circuit.The maximum pressure of each loop line of the closed circuit is limited by the main relief valves to 37990 689 kPa (5510 100 psi). The pressure is above the low pressure side of the main loop circuit.Main Relief Function
Illustration 3 g00459561
Relief valve cross section (1) Main relief valve (2) Locking cap (3) Conical spring (4) Collar (5) Spindle (6) Spring (7) Collar (A) Oil passageOil from the vibratory pump flows through the main relief valve (1) at the oil passage (A). High pressure oil enters passage (A) and the oil acts on the collars (4) and (7). The force of spring (6) keeps the valve closed until the oil pressure in the high pressure side of the main loop circuit reaches relief pressure. After the relief pressure is reached, the pressure moves the spindle (5) downward while the pressure compresses the spring (6). The relief oil flows from the high pressure side to the low pressure side of the main loop. The oil flows through the gap between the spindle (5) and the collar (7). The arrows show this flow in illustration 3. High pressure oil enters the low pressure side of the main loop circuit until the force of the spring (6) seats the spindle (5) and the collar (7) .Make Up Function
Illustration 4 g00782331
Relief valve cross section (1) Main relief valve (2) Locking cap (3) Conical spring (4) Collar (5) Spindle (6) Spring (7) Collar (A) Oil passageOil from the vibratory pump flows through the main relief valve (1) at the passages (A). The force of the spring (3) and the oil pressure in passage (A) keep the collar (7) closed. Charge pressure acts on the bottom of collar (7) and the spindle (5). When the oil pressure in passage (A) drops below the charge pressure, collar (7) and the spindle (5) move upward compressing the spring (3) .The charge oil flows through the gap. The closed loop circuit will be replenished with the makeup oil. The arrows show this flow in illustration 4. Charge oil continues to replenish the low pressure side of the circuit with the make up oil until the pressure in passage (A) becomes greater than the charge pressure.Pump Control
Illustration 5 g00460011
Control valve (1) Springs (2) Solenoid (3) Valve spool (4) SolenoidThe control valve is attached to the vibratory pump. The valve is a three-position solenoid. The valve is