An Empirical Study on the Wear of Reciprocating Hydraulic Rod Seals Using 15 Different Oils

Abstract

Hydraulic oils differ in their chemical composition and viscosity substantially. Their influence on the wear of rod seals is neither fully understood nor can be predicted precisely. The primary objective of this study was to evaluate the influence of various oils and their wetting properties on the wear of rod seals. In an empirical study, the wear of 30 commercially available polyurethane U-cups was investigated with 15 different oils using a recently built test rig. The wear of rod seals increased with lower viscosity and higher polarity of the oil. Both oil properties are combined in a new parameter which helps to assess the lubricity of oil and the wear of rod seals.

Regenerative Thermoplastic Polyurethane for Hydraulic Rod Seals – Time-Accelerated Testing

“…The leakage and the wear of seal rings were measured in accordance to previous work (e.g. [2]). According to [3], the surface condition of the hydraulic rods is decisive for the wear of the seal rings.…”

“…The test conditions were chosen in accordance with [2]: The test duration was 400000 double strokes (approximately 534 hours), resulting in a cumulated sliding distance of 400 km for each set-up with a 0.5 m single stroke. The operating conditions were constant during the test time.…”