Stenso - Hovedkatalog 2019

Calculations Designing and sizing of guide ring for dynamic applications is dependent to a lar- ge extent on the radial force and the associated deformation of the slide material, guide ring cut part and the service temperature. The value of dynamic comp- ressive strength is to be considered taking the above factors into account. In prac- tice, it is advantageous to include a factor of safety. Where: B = min. width of slide ring [mm] min F = max. radial load [N] R = permissible dynamic compression . zul. dyn strength [N/mm²] S = safety factor D = nominal diameter [mm] n B min [mm] > .F S R . D zul. dyn. n Rod diameter D = 63 mm n Max. radial load F = 4 kN R dyn. compress. strength = 15N/mm² zul. dyn Safety factor S = 2 B min 8,5 > . 4000 2 . 15 63 Example: In accordance with above calculations, a choice can be made as 1 Guide strip for groove width of 9.7 mm (part N°. FB 63/68x9,7/X-5640) 2 Guide strip for groove width of 5.6 mm (part N°. FB 63/68x5,6/X5640) To achieve as much of a guide surface in length as possible, incorporation of two guide ring is to recommended. ~ Guide strip The guide strip has a rectangular cross section and is provided with a chamfer on all edges. Thus, non-permissible edge pressures in the groove corners are avoided. The chamfer also serves to simplify assembly.Guide strips are produced in various cross-sections as cut-out pieces. They are also available as cuttings (elongated lengths), suitable to every piston and rod diameter. The gap (m) is to be specially taken into account to ensure safe function and undisturbed operation of the seal. As a rule, the ends are provided with bevel cut.Astraight cut or Z- cut are also possible. Material Data Compound Temperature [°C] Max. compress. resist. dynamic PTFE Guide strips have proven their superi- ority for use on pistons and piston rods for hydraulic and pneumatic cylinders. Particularly in the case of hydraulic cylinders under variable loads, very small or large stroke speeds and fluctuating temperatures, these guide strips are preferentially used (e.g. mobile hydraulics,machine tool and presses manufac- turing, agricultural machinery, vehicle and trucks industry etc.). Good mechanical characteristics of the guide ring and the materials coupled with their ability to absorb dirt particles present in the pressure medium and good frictional behaviour guaran- tee long service life even in tough and deman- ding service conditons. AF-5640 AF-2426 30 15 90 10 150 7 30 8 90 6 150 4 192 FB Guide Strip Materials Overview: AF-5640: PTFE with Bronze/additive: high abrasion resistance and inherent stability, very good shear characteristics, good chemical resistance, used in intermediate to high stress hydraulics application. AF-2426: PTFE with Carbon: good abrasion resistance and inherent stability, good chemical resistance, used in water and water-oil emulsions with intermediate stress. Also designed for dry runs.