Rex Linkbelt Roller Chain Catalog - Norfolkbearings.com

Drive EngineeringDrive InstallationAccurate alignment, proper chain tension, good lubrication, and periodicinspection are required to obtain maximum chain and sprocket life.To assist you in safely installation chain and sprockets, careful attention should begiven to the following instructions.Caution: Shut off all power to the equipment so that it cannot be startedaccidentally during these installation steps. Failure to do so can result in seriouspersonal injury.33635Shaft alignment • Mount the sprockets on their respective shafts. As illustratedin Photo 33635, align the shafts horizontally with a machinist’s level, and adjustthe shafts for parallel alignment with a vernier, caliper, or feeler bar. The distancebetween shafts on both sides of the sprockets must be equal. When shafts havebeen accurately aligned, the motor, bearings, etc., should be bolted securely inplace so that alignment will be maintained during operation.Sprocket alignment • Sprockets must be in axial alignment for correct chain andsprocket tooth engagement. Apply a straight edge, or heavy cord to the machinedsprocket surfaces as shown in Photo 33636. When a shaft is subject to end flat,the sprocket should be aligned for the normal running position. Tighten set screwsin sprocket hubs to guard against lateral movement and to hold key in position.Aligning shaftsCChain installation • Inspect chain to make sure it is free from dirt or grit before itis installed. Fit the chain around both sprockets bringing the free ends together onone sprocket as shown in Photo 33637. Insert connecting link and secure in place.33636Note: Due to their flexibility, chains can be somewhat difficult to handle. Wheninstalling the chain, pick it up by the end links to avoid the possibility of pinchingfingers or hands. Failure to do so may result in personal injury.Aligning sprocketsChain tension • Adjust drive centers for proper chain tension, as outlined below.Normally, horizontal and inclined drives should be installed with an initial sag equalto approximately 2% of sprocket centers.Vertical center drives, and those subject to shock loading, reversal of rotation,or dynamic braking, should be operated with both spans of chain almost taught.Periodic inspection of such drives should be made to avoid operation withexcessive slack and to maintain proper chain tension.To determine the amount of sag, pull one side of the chain taught allowing all theexcess chain to accumulate in the opposite span. As illustrated in Photo 33638,place a straight edge over the slack span and, pulling the chain down at the center,measure the amount of sag. If necessary, adjust drive centers for proper sag thatwill result in correct chain tension.Shaftcenters,inchesSag,InchesSag in inches based on 2% of sprocket centers20 30 40 50 60 70 80 90 100 125 150.50 .63 .88 1.00 1.25 1.50 1.63 1.88 2.00 2.50 3.00Inserting connecting link33637Caution: To avoid serious personal injury, the drive should be enclosed in acasing or safety guard. Consult Rexnord Industrial Chain for casing installationprocedures. If the drive is not enclosed, clear the area of tools and otherinstallation equipment before reconnecting the power.33638Determining chain sagC-47