🔍 Key Concepts

• Pressure vs. return (outlet) side of a radial piston hydraulic motor • How the pintle valve ports connect to each piston as the cylinder block rotates • Relationship between direction of rotation and which piston is on the power (pressure) stroke

💭 Think About

• Look at the shaded passage connected to the fluid inlet. Which piston is directly in line with that high‑pressure passage? • Based on the direction of rotation shown by the arrow, which pistons are about to be pushed outward by incoming pressure, and which one is being pushed back in toward the outlet? • How does the position of each piston head against the reaction ring tell you whether it is on a pressure stroke or a return stroke?

✅ Before You Answer

• Identify clearly which side of the pintle valve is the fluid inlet (high pressure) and which is the fluid outlet (low pressure/return). • Trace the inlet passage from the pintle valve to see which piston bore it lines up with exactly at this instant. • Confirm the indicated rotation direction and ensure the piston you choose would, in that rotation, be driven against the reaction ring by pressure rather than moving inward toward the outlet.