Zenith C-30HDG manual Roller Chain Application, Working Loads, Installation and Drive Alignment

C-30HDG PUMP — MAINTENANCE (PUMP)

Roller Chain Application

A properly selected, installed and maintained drive chain (Figure 27) is an extremely versatile means of power transmission. It is possible, however, to greatly reduce a chain’s life and even induce failure if the chain is abused through improper installation, operating or maintenance procedures. In certain applications, failure can lead to personal injury or property damage.

Figure 27. Drive Chain

Recommendations and comments on how to get the most from your roller chain drive are given in this section.The drive chain used in the MAYCO C-30HDNI pump is manufactured by the

"DIAMOND CHAIN COMPANYTM"

Working Loads

UTS-Ultimate Tensile Strength-is the one time pull required to break the chain. For single strand chain, the load (pull) applied to the chain in service should never exceed 1/6th of the UTS for the chain being used except as noted below.

It is possible to exceed the allowable working loads for a limited number of cycles, but you should contact Diamond Chain Company before this is considered. A roller chain should never be loaded above 50% of UTS for even one cycle.To do so will damage the chain structure and reduce its capacity.

The UTS or one time breaking load of multiple strand chain is the UTS of a single strand chain times the number of strands; i.e., two strand chain is twice as strong as single.

When allowable working loads are considered, however, the capacity of each strand in a multiple strand chain is only 65% of the single strand rating; thus, three-strand chain would rate not three times single but only 1.95 times.This is because the chain load cannot be exactly distributed across all three strands of the three-strand chain.

Installation and Drive Alignment

Chain and sprockets (Figure 28) must be installed correctly. Sprockets must be properly aligned and sprocket shafts must be parallel so the drive will run in a plane perpendicular to them. Axial alignment should be checked with a straight edge which will extend across the finished sides of the sprockets.They should be true-running with minimum wobble and eccentricity.The higher the drive speed, the more important these details become.

Figure 28. Shaft and Drive Sprocket Alignment

The chain should be installed so the slack span is properly tensioned.To check chain tension (Figure 29), turn one sprocket to tighten the upper span of the chain while holding the other sprocket fixed.The lack span should have 4-6% of span length in the mid-span movement for horizontal drives and 2-3% for vertical drives.

Figure 29. Drive Chain Tension

A roller chain’s capacity can be significantly reduced if it is twisted or bent sideways in the direction of the pin axis.Exercise particular care in alignment of hoist or other applications where loads are suspended near personnel.

MAYCO C-30HDG PUMP — OPERATION AND PARTS MANUAL — REV. #6 (04/02/12) — PAGE 45