BOLT HEX SOCKE 1C4230 - Caterpillar

High Pressure Stall
Hydraulic Pump
(1) Input shaft. (2) Pump controller. (3) Spring. (4) Plug. (5) Pressure compensator spool. (6) Passage. (7) Passage. (8) Flow compensator spool. (9) Spring. (10) Ball check. (11) Passage. (12) Passage. (13) Bias spring. (14) Swashplate. (15) Actuator piston. (16) Passage. (17) Passage. (18) Piston. (19) Cylinder barrel. (20) Port plate.When the hydraulic system stalls under load or when the cylinders reach the end of the stroke, system pressure increases. The signal oil pressure in spring (9) cavity becomes equal to the pump output pressure. The combined force of spring (9) tension and signal oil pressure causes spool (8) to shift right.Pump output pressure in passage (7) flows past spool (8) up to pressure compensator spool (5). When system pressure reaches 20 700 350 kPa (3000 50 psi), the oil acting against the pressure compensator spool overcomes the tension of spring (3) causes the pressure compensator spool to move left.When spool (5) moves left it opens passage (6) to passage (7). Pump output oil can now flow through passage (7), past spool (5) into passage (6). Then the oil unseats ball check (10) and flows into passage (17).This oil acts against the actuator piston and overcomes the tension of bias spring (13) and causes the actuator piston to move to the left. As the actuator piston moves left it causes swashplate (14) to move toward minimum angle or destroke. This decreases pump flow and pressure. Pump output decreases while system pressure is limited to 20 700 350 kPa (3000 50 psi).Ball valve (10) prevents damage to the pump during stall conditions. Ball valve (10) allows system pressure oil to bypass the margin spool and flow to actuator piston (15).Metering Pump (Steering)
Metering Pump (Steering)
(1) Signal line. (2) Metering pump (steering).Metering pump (2) is located under the operator station floor plates at the base of the steering column. Signal line (1) is routed from the metering pump back to the steering pump controller.
Metering Pump
(1) Cylinder relief valve. (2) Anti-Cavitation valve. (3) Outlet to tank. (4) Left cylinder port. (5) Right cylinder port. (6) Inlet from pump. (7) Passage. (8) Passage from Gerotor. (9) Drive. (10) Gerotor. (11) Check valve. (12) Springs. (13) Shaft spool. (14) Pin. (15) Sleeve. (16) Passage to Gerotor.The metering pump has two main sections; control section A and pump section B. These two sections work together to send oil to the steering cylinders.The direction and speed of a turn are controlled by the metering pump. As the steering wheel is turned faster, there is an increase in the flow of oil to the steering cylinder. This increased flow causes the cylinder to move farther and faster, which turns the machine faster.When the steering wheel is not being turned, control section A is in the NEUTRAL position. The metering pump is a closed center valve, so there is no alignment between the passages in the spool and orifices in the sleeve in this position. Only a small amount of oil