Excavator Pump Parts A10VS071 VALVE PLATE 243-4501 REXROTH (A10VSO71) Excavator Spare Parts Porting & Commutation: During cylinder block rotation, every plunger chamber cycles between high‑pressure and low‑pressure oil passages to carry out suction and discharge, functioning without a standalone directional valve. Sealing & Partitioning: An oil film friction interface forms together with the cylinder block end surface to isolate high/low pressure zones and restrict internal