Rex Linkbelt Roller Chain Catalog - Norfolkbearings.com

Drive EngineeringLubricationGenerally, chains should be lubricatedto achieve and maintain high operatingefficiency and provide long service life.Factors such as operating conditions,chain size, type of service, and method oflubrication influence the life of chain. Manylow-speed drives perform successfullywith little lubrication, but where operatingconditions permit, longer chain life will resultfrom adequate lubrication.The primary purpose of chain lubrication is toprovide a clean film of oil at all load-carryingpoints where relative motion occurs. Toeffectively lubricate the chain joints, oil mustbe delivered to the spaces indicated in Figure7913. The oil should be directed to the insideof the lower span of chain so that it will notbe thrown off by centrifugal force before itpenetrates the chain joint.INSIDE THE ROLLERFactory ROLLER prelubricationCHAINFig. 7913Laboratory tests and actual experience showthat chain joint ROLLER friction CHAIN is greatest during therun-in period, the span of time between drivestart-up and the point at which the lubricationsystem begins to function effectively. Tominimize joint friction during this criticalperiod of operation, Rexnord roller chains arefactory prelubricated.Laboratory tests show that prelubricationreduces joint wear during the critical run-inperiod by approximately 50%. The result islonger operating life for the chain.Subsequent maintenance of a clean oilfilm between all bearing surfaces is equallyimportant for high operating efficiency.Selection of the lubricantDrives operating at room temperaturesshould be lubricated with an S.A.E. 30mineral oil. For operation at high or lowtemperature extremes, oils with higher orlower viscosity numbers should be used,such as those listed below.Temperature of atmospheresurrounding drive,degrees FahrenheitS.A.E.viscositynumber–20 to 402040 to 10030100 to 12040120 to 14050BETWEEN THE SIDEINSIDE THE ROLLERBARS TO THE PINPetroleum oils should not be used to lubricateBETWEEN THE drive SIDE chains operating in temperaturesINSIDE THE ROLLER BARS TO THE PIN above 300°F (149° Celsius). Under certainoperating conditions, chains operating inBETWEEN THE high SIDE temperature atmospheres can beBARS TO THE effectively PIN lubricated with colloidal graphiteFig. 7913ROLLER CHAINFig. 7913dispersed in a suitable volatile carrier. Thesesolutions penetrate the chain joints and, uponevaporation of the carrier, leave a thin depositof graphite on the chain joint surfaces.This type of lubricant may be applied bydrip-feed or wick-feed oil cups. Consult alubricant manufacturer for recommendationswhen chains are required to operate attemperatures between 300°F and 700°F(149° and 371°C).Suggested methodsof lubricationSeveral methods for lubricating chain driveshave been developed, each fitting a particularrange of operating conditions. Horsepower,chain speed, and the relative position ofshafts are primary considerations. Thevarious methods suggested and their rangeof application are described below.Manual or drip lubrication may be usedfor open running drives (those enclosed by asafety guard) which operate in a non-abrasiveatmosphere. These methods should beconfined to low horsepower drives operatingat low chain speeds. The lubricant may beapplied to the clearances between sidebarswith a brush, oil can, or drip-cup oiler.Drip-cups are usually mounted on a pipewith drilled holes spaced to distribute oilbetween the sidebars in the lower span ofchain. About 4 to 10 drops per minute aresufficient to lubricate very slow speed drives,while a minimum of 20 drops per minute isrecommended for higher speeds.The relative position of shafts is not a factorwhen these methods of lubrication are used.Bath lubrication is the simplest automaticmethod of lubricating encased chain drivesand is highly satisfactory for low or moderatespeeds.OIL LEVELOIL LEVELFig. 6579OIL LEVELThe chain dips into an oil reservoir to a depthof about one-half inch, forcing the lubricantinto the chain joints. Only a short length ofchain should run through the oil, preferablyonly that portion on the bottom of the lowersprocket.The relative shaft positions illustrated beloware recommended when oil bath lubricationis used:OIL LEVELFig. 5243Fig. 6579Fig. 6579COIL LEVELFig. 5245Fig. 5243OIL LEVEL OIL LEVELFig. 5243Fig. 5245Fig. 5245OIL LEVELOIL LEVELC-45