Excavator Pump Parts A7VO107 Retainer Plate Rexroth R902024999 High-quality Replacement Parts

Excavator Pump Parts A7VO107 Retainer Plate Rexroth R902024999  High-quality Replacement Parts

Core Functions

Forcing piston retraction (suction stroke) The swash plate pushes the pistons inward to complete the oil‑discharge process. When rotating to the suction half‑cycle, the internal chamber pressure is low and there is no force to pull the pistons out. The Set‑Plate holds all Piston Shoes and forcibly pulls the pistons out of the cylinder block, increasing the volume of cylinder bores to achieve oil suction.

Restraining and positioning all piston shoes The necks of piston shoes pass through the holes of the retainer plate, keeping the nine piston shoes at correct circumferential positions and preventing the shoes from offsetting or tilting. The set plate revolves synchronously as the cylinder block rotates, ensuring consistent posture for all piston shoes.

Transmitting spring preload to keep piston shoes pressed against the Swash‑Plate Thrust from the central spring → Ball Guide → Set‑Plate → all piston shoes. This continuously presses the piston shoes against the working surface of the swash plate and prevents separation of shoes from the swash plate. Once separation occurs, the pump will immediately lose pressure and suffer severe damage.

Withstanding centrifugal force under high‑speed rotation It counteracts the centrifugal ejection force generated by rotating piston shoes to stop the shoes from flying outward. It maintains the hydrostatic oil film between piston shoes and swash plate and reduces wear.

Typical Failures After Damage

Worn and enlarged plate holes, warping deformation: piston shoe wobble and eccentric wear

Broken hole edges: piston shoe dislodgement, damage to swash plate and cylinder block

Abnormal pump noise, insufficient pressure, low flow rate, poor oil suction, high pump temperature and excessive internal leakage

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