STRUCTURE AND FUNCTION HYDRAULIC PUMP SHUTTLE VALVE RKS00200 1 2 3 1. Valve 2. Plug 3. Cover FUNCTION The shuttle valves are installed in covers of pump swash plate control pistons. They select lower pres- sure either travel PPC pressure or AS valve pressure, and output to pump swash plate control pressure. D B A C F 2 F 1 1 E RKS00210 OPERATION Port C is connected to port A (Travel PPC pressure inlet port). And hydraulic force F1 by travel PPC pressure ac- tuates the valve (1). And port D is connected to port B (AS pressure inlet port). Hydraulic force F2 by AS valve pressure actuates the valve (1).
By the hydraulic force F1 and F2 , the shuttle valve selects lower pressure either PPC pressure or AS valve pressure. It outputs lower pressure of them from port E to control pump swash plate. 10-31 SK818-5 SK820-5 turbo