Roller Chain - Tsubaki

Roller ChainInstallation & Maintenance8.3 Pin RelatedProblemsBreakage of pin.Possible CausesExcessively large shock loads.Subject to a repetitive load greater thanthe fatigue limit of the pin.Corrosion.SolutionReduce shock loads by making the start-up, stopping, andother actions smoother.Remove the large repetitive load or increase the size ornumber of chains.Install a casing to protect the chain. Periodically clean andlubricate the chains.Drive Chain(1) Static fracture.The type of fracture found when subjectingthe chain to the breakage test. Occurswhen chain is subjected to a load greaterthan its breakage strength.(2) Fatigue fracture.Occurs when the pin isrepetitively subjected to loadsgreater than its fatigue limit. Recheckthe size of the peak loadand formulate a countermeasure.(3) Shock-induced bending fracture.The pin is subjected to a large shock load andbreaks. The side with the initiating point receivestensile load, and the fracture progresses fromthis point. A pin is especially susceptible tobecoming weak with regard to bending when thesurface of the pin has corroded.Pin rotates or begins tostick out.Wear or rust occursonly at the connectingpin in a liftingapplication or similaroperation.Excessive load or improper lubrication.Operating a chain at high load withoutproper lubrication can create frictionbetween the pin and bushing, causingthe pin to rotate. In this condition, thepin may come out, leading to chainbreakage.Improper initial lubrication at installation.Replace with new chain. Improve the lubrication or loadingconditions.Replace with new chain immediately. Do not weld or reusethe pins. If the pin head or link plate surface is worn, checkthe installation.Replace the connecting link. If pin wear is excessive, alsoreplace the chain. Properly install the connecting section fordevices such as end brackets used for lifting applications,etc.A-121