Excavator Pump Parts Kayaba Piston Shoe PSVD2-27E PSVD2-26E Set of 10 pcs Excavator Parts

Excavator Pump Parts Kayaba Piston Shoe PSVD2-27E PSVD2-26E Set of 10 pcs Excavator Parts

Thrust Transmission and Angle Self-Adaptation
Pistons perform reciprocating linear movement inside cylinder blocks; the swash plate remains fixed in inclined orientation. With spherical hinge coupling, the piston shoe swings flexibly along with swash plate tilt and transfers piston axial thrust uniformly to the swash plate. In the absence of piston shoes, piston ball heads contact the swash plate in point mode, causing rapid crushing and serious wear.

Shift from Point Contact to Surface Contact for Stress Reduction
Piston ball heads are spherical, and piston shoes are designed with wide flat bottom surfaces.
Ball head ↔ Piston shoe: movable spherical articulated joint
Piston shoe base ↔ Swash plate: sliding surface contact
Wider contact surface cuts unit pressure to fulfil long-time operating demands of high-pressure pumps.

Hydrostatic Oil Film Lubrication (Critical Function)
A micro throttling orifice is positioned at the piston shoe’s centre. High-pressure oil passes through piston internal channel, ball head and orifice into bottom recess and generates a 10～30 μm thin high-pressure oil film between two mating surfaces.
Key values:
✅ Replace dry metallic friction with fluid friction
✅ Avoid scuff damage and overheating burnout on piston shoe and swash plate
✅ Carry off heat generated in friction process
Surplus oil flows into pump housing and acts as internal leakage return oil.

Keep Firm Contact Supported by Retainer Plate
The set plate presses the rear of piston shoes to maintain permanent attachment to swash plate. As cylinder block rotates one complete circle, every piston completes one suction and one delivery stroke; piston shoes slide continuously on swash plate surface.

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