Life tests on elastomeric lip seals for pneumatic cylinders

Abstract

Keywords IN TRO D UC TI0 NA test method and a testing machine for evaluating the wear of lip seals for pneumatic cylinders are presented. The method and the machine have been evaluated with tests on different types of seals for cylinders with a 50 mm bore. Three levels of lubrication condition were examined: dry, with a film of grease, and with an optimum amount of grease. Differences were noted both between these conditions of lubrication, and between types of seal. 0 Leaf Coppin 1997

Experimental Method for Investigating Air Leakage in Rodless Cylinders

“…The bench is shown in Figure 3. Cylinder under test (1) is secured to horizontal base (2). Slide (3) can be blocked along its stroke by means of a system consisting of bracket (4), which is positively connected to the slide, shaft (5), and upright (6), which is positively connected to base (2).…”

“…Cylinder under test (1) is secured to horizontal base (2). Slide (3) can be blocked along its stroke by means of a system consisting of bracket (4), which is positively connected to the slide, shaft (5), and upright (6), which is positively connected to base (2). Load cell (7) measures the force at the axis of shaft (5), thus making it possible to calculate moment M applied to the slide-piston assembly.…”

“…The tension on band ( 8) is adjusted by means of the loading system installed between the band and angle bracket (9) positively connected to base (2). The end of the band is held in clamp (10), while the force is adjusted by means of screw (11) and measured by load cell (12).…”

“…Many investigations have thus analyzed the tribological parameters of the seal-barrel interface and the most influential operating conditions, viz., grease and lubrication conditions, seal/counterpart material, seal cross-sectional geometry, and surface finish. Belforte et al 1,2,3 developed a method for evaluating pneumatic actuator service life and performance, with particular reference to piston and rod seals. Tests demonstrated the importance of lubrication conditions and of seal geometry and materials, while an extensive failure analysis and classification of damage modes made it possible to establish preventative maintenance procedures.…”

Pneumatics in Italy

“…Here again, the approach used benefits from a wide range of methods, including numerical techniques (FEM) to evaluate the stress field [6], photoelastic techniques [7], and extensive experimental activities [8]. By way of example, Figure 14 shows the deformed and undeformed geometry of a lip seal in operating conditions with a fluid pressure of 6 bar.…”