STRUCTURE AND FUNCTION HYDRAULIC PUMP 2. Control of discharge amount If swash plate angle α becomes larger, the difference between volumes E and F becomes larger and discharge amount Q increases. Swash plate angle α is changed by control piston (5). Control piston (5) moves in a reciprocal movement ( ) according to the signal pressure from pilot line (PPC and AS valves). This straight line movement is transmitted through slider (6) to rocker cam (4), which is supported by the cylindrical surface to cradle, slides in a rotating movement in direction ( ). On this pump, maximum swash plate angle is ± 15.8°.. Screw A restricts to the maximum stroke of control piston (i.e.
maximum displacement of each pump). When screw A is tightened, maximum displacement decreases, and when screw A is loosened, maximum displacement in- crease. This screw should be adjusted when the machine doesn’t travel straight or machine maximum speed is little bit wrong. Screw B is the fine adjuster of neutral position of control piston (5). That adjust prevent machine from creep. B A A 5 6 4 RKS02170 10-19 SK818-5 SK820-5 turbo 3 4 RKS00280 RKS00360 5 6 4 3