BRACKET AS 3844301 - Caterpillar

Illustration 1 g02690898
Valve group
(1) Line to the oil cooler inlet
(2) Line from the oil cooler outlet
(3) Return line to the hydraulic tank
Illustration 2 g02690917
(1) Line to the oil cooler inlet
(2) Line from the oil cooler outlet
(3) Return line to the hydraulic tank
(4) Bypass check valve
(5) Slow return check valve
(6) Return passage from the main control valve The return oil flow through slow return check valve (5) is divided into two flow paths. A portion of the oil flows through inlet line (1) to the hydraulic oil cooler. The oil flow from the hydraulic oil cooler flows to outlet line (2) and through return line (3) to the return filter in the hydraulic tank. The remainder of the return oil flows through bypass check valve (4).When the temperature of the return oil in inlet line (1) is very low, the viscosity of the oil is high. The flow resistance of the return oil in inlet line (1) is high. Thus, the pressure of the return oil is high.As a result of the high pressure of the return oil, bypass check valve (4) opens. Most of the return oil flows through bypass check valve (4) and return line (3) to the return filter in the hydraulic tank. The remainder of the oil flows through inlet line (1) to the hydraulic oil cooler. Since a small amount of the return oil flows to the oil cooler, the temperature of the oil increases. As the oil temperature increases, the return oil pressure decreases. Bypass check valve (4) begins to close. A greater portion of the return oil flows to the hydraulic oil cooler. Bypass check valve (4) maintains the hydraulic oil at the optimum operating temperature.