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■Operation interval and PV value In the operation of the bearing, there are continuos and intermittent operations. In general, an intermittent operation with some intervals creates favorable condition for the better results because suspension of operation cools down the temperature of the friction surface. However, this frequent start and stop increases wear by inadequate lubrication. It causes galling or seizure at the time of start. A self-lubricating bearing supplies lubricating oil or forms solid lubrication film onto the frictional surface and prevents drop in the bearing performance even in such an inadequate lubrication operation. The diagram shows influence of intermittent motion and continious motion on PV characteristic in the radial journal rotational motion and oscillating motion of Oiles 500SP. Self-lubricating bearing has higher limit PV value as the stopping interval is increased. ■Selection of mating materials Bearing performance is influenced by the material, hardness, surface roughness and surface treatment of the mating shaft. In order to select appropriate mating material, please refer to the below. ■Foreign particle tolerance (resistance) Although contamination by foreign particles do not affect the performance of self-lubricating bearings compared to the ball bearings, it may deteriorate performance of the bearing. Following measures are recommended: ●Surface hardening treatment such as induction hardening, as well as carburizing should be implemented onto the mating shaft. ●At the both ends of the bearing, install dust seal and fill with grease. ●Periodic greasing prevents contamination of foreign particle and helps discharging of the foreign matters. Influence of operation mode on PV value. 0 0 4.9 9.8 14.7 19.6 24.5 30 60 90 120150180210 Cycle〔cpm.〕 Contact pressurec N/mm2 500 hour continious operation 2 sec. operation and 5 sec. interval 1 sec. operation and 6 sec. interval 1 sec. operation and 12 sec. interval Up to 24.5{250} 24.5{250} to 49.0{500} 49.0{500} to 98.0{1,000} Up to 49.0{500} 49.0{500} to 98.0{1,000} Bearing Contact pressure Hardness N/mm2 {kgf/cm2} Surface roughness Ra(Ry) Material Less than 1.6a(6,3s) Less than 0.8a(3.2s) For the plastic bearing OILS 480, use mating material of more than HRC 45 hardness. HB150 or over HB250 or over HRC50 or over HB120 or over HRC45 or over Carbon steel for machine structure alloy steel (S45C、SNC415、SCM435) Corrosion resistant steel.(SUS304、SUS316) Surface hardening treatment such as induction hardening and carburizing should be implemented for carbonsteel for machine and alloy steel. In addition to surface hardening treatment as above, additional surface treatment such as nitriding treatment and hard chrome plating should be implementd. Carbon steel for machine structure alloy steel (S45C、SNC415、SCM435) Corrosion resistant steel.(SUS304、SUS316) Surface treatment such as induction hardening, quenching by carburizing and hard chrome plating should beimplemented for carbonsteel for machine and alloy steel. Metallic Bearings Plastic and Multi-layer Bearings 338 Selection Guide Product Information Plastic Bearing Multi-layer Bearing Metallic Bearing Air Bearings Technical Slide Shifter Information Corporate Profi le Technical Information