🔍 Key Concepts

• Radial piston hydraulic pump construction: which parts rotate, which stay fixed • How eccentricity (off-center position) between the rotating cylinder block and the reaction ring changes piston stroke and displacement • Why changing flow direction in this type of pump is usually done by reversing the geometry, not by throttling or changing pintle size

💭 Think About

• Looking at the figure, which component appears to be connected to the drive shaft and must stay centered for smooth rotation? • Which component could practically be shifted off-center to make the pistons stroke more or less as they rotate around? • If you move that adjustable component to the opposite side of center, how would that reverse which side of the pintle valve sees discharge vs suction?

✅ Before You Answer

• Identify which part is fixed to the shaft (cylinder block vs reaction ring) in a typical variable-displacement radial piston pump • Decide which part can realistically be moved off-center during operation to vary piston stroke without changing speed or throttling • Confirm that the same adjustment method can change both flow quantity and direction, not just one or the other