TL;DR
A processing plant needed to replace a worn and corroded conveyor drive assembly — split bearing, shaft, sprocket, collar, and spacer — with no manufacturer drawing available. The path forward was to measure the assembly in the field, recover the chain specification, and spec each component individually rather than duplicate the whole drive.
The Problem
The existing drive assembly showed significant wear and corrosion, and it had to be replaced. The manufacturer could not readily supply a replacement, and no drawing of the assembly was on hand. Every component — bearing, shaft, sprocket, split collar, and spacer — had to be identified and sourced independently.
The Technical Challenge
A drive assembly is only as good as its least-specified part. In this case the hardest item was the sprocket, because it depends on the chain:
- The chain is an older design and may not be supplied by a mainstream chain manufacturer.
- Without a chain drawing, the sprocket cannot be specified from the manufacturer's catalog.
- If the chain manufacturer will not provide a drawing, the sprocket must be specified from first principles: roller outside diameter, pitch, and roller width.
The bearings, shaft, collar, and spacer are more standard, but each still has to match the existing mounting interface and the operating environment.
How RBC Solved It
- Measure the assembly in the field. Shaft size and floor-to-shaft-center, bolt-to-bolt mounting, and base width for the bearing; shaft OD and length; sprocket tooth count, OD, width, hub diameter and thickness, keyway, tooth thickness, and pitch diameter; chain number; split collar and spacer dimensions.
- Recover the chain specification. Request the chain supplier and a drawing from the plant's purchasing department. If no drawing is available, obtain the roller OD, pitch, and roller width — enough to match the chain to an existing standard.
- Spec the sprocket. Once the chain is identified, match the dimensions to an existing chain and source a sprocket for it — including a cast sprocket with a chilled rim for hard teeth where the environment warrants it.
- Evaluate split versus solid construction. Based on conveyor location and access, split sprockets may be the practical choice for installation.
- Source the bearing and collars. Work the mounted-bearing and split-collar options that fit the measured interface, including split cast collars.
Where the original manufacturer's engineering records still exist, they are the fastest source of a chain or sprocket drawing — plants often retain drawings for everything they run. That is the first call to make.
The Result
- Every component of the drive assembly identified and sourced from field measurements.
- No dependency on a discontinued original assembly.
- A sprocket specified to the actual chain, with construction chosen for the environment.
Key Value Delivered
| Area | What RBC Provided |
|---|---|
| Field engineering | Measured the assembly and built a component specification |
| Chain identification | Recovered or reconstructed the chain specification |
| Sprocket sourcing | Matched chain dimensions and specified construction |
| Bearing and collar | Sourced mounted bearing and split-collar components |
| Single point of contact | One distributor across the whole drive train |
When You Have No Drawing
- Measure everything that interfaces with something else — mounting, bores, keyways, center distances.
- Identify the chain before the sprocket; the sprocket cannot be specified without it.
- Ask the plant for retained drawings — they often exist.
- Consider upgrades (material, bearing style, split construction) while you are re-specifying anyway.
Rebuilding a conveyor drive with no drawing? RBC Industrial measures, specs, and sources complete power-transmission assemblies. Call (915) 845-8188 or request a quote at rbc-industrial.com.