CABLE AS-BATTERY 1113760 - Caterpillar

Illustration 1 g00977614
(1) Left steering cylinder (2) Right steering cylinder (3) Servo cylinder (4) Check and relief valve for the steering cylinders (5) Steering control valve (6) Centering spring (7) Strainer (8) Flow control valve (9) Pressure reducing valve (10) Control spool (11) Orifice (12) Pilot relief valve (13) Hydraulic filter (14) Flow switch (15) Check valve (16) Check valve (17) Secondary steering pump (18) Steering pump (19) Supplemental steering circuit (20) Hydraulic tank (21) Check valve for the steering metering pump (22) Steering metering pumpIf the engine has stalled or steering pump (18) has failed, the secondary steering attachment can operate the steering cylinders.Secondary steering pump (17) is turned by the ring gear of the differential when the wheels turn. When the ring gear turns the secondary steering pump, oil flows into the steering hydraulic system. The oil output from secondary steering pump (17) adds to the oil output from steering pump (18) when the machine is moving forward.Check valve (15) for steering pump (18) and check valve (16) for secondary steering pump (17) are also part of the secondary steering attachment. The oil from the secondary steering pump always flows through check valve (16) when the machine is moving forward. Check valve (15) prevents oil from the secondary steering pump from flowing into steering pump (18) if there is a failure in either the steering pump or the engine.Secondary steering pump (17) is a two-section pump. When the pressure at steering pump (18) falls below 414 kPa (60 psi), the output from both secondary steering pump sections goes through the check valve and through hydraulic filter (13) into steering control valve (4). When the pressure at steering pump (18) is above 1240 kPa (180 psi) the output from the large pump section of the secondary steering pump goes back to the inlet of steering pump (18). Only the output from the small pump section goes through check valve (16) and through the filter to steering control valve (4) .The amount of oil from secondary steering pump (17) is relative to the RPM of the wheels. When the RPM of the wheels decreases, the output of oil from secondary steering pump (17) decreases. This causes steering cylinders (1) and (2) to move slowly. If the speed of the wheels decrease, the machine turns slowly.