A CDLR conveyor drives every roller through a chain rather than a belt or o-ring, which is why it carries loaded pallets, drums, and steel containers that would stall a belt-driven line. The chain drive also tolerates conditions that kill other conveyor: dirty, oily, and hot loads. HOJ engineers CDLR into pallet conveyor systems built around the loads you actually run.

How the Drive Works

On a roll-to-roll CDLR, each roller is coupled to the next with roller chain, typically No. 40, 50, or 60 depending on roller centers, so torque passes down the bed roller by roller. The center drive can be placed in any section of the conveyor length. Rollers run on sealed, pre-lubricated ball bearings through a sealed worm gear C-face speed reducer, and formed steel upper and lower chain guards totally enclose the drive chains.

That construction is the tradeoff. You get positive drive and traction under heavy loads, and you accept a chain drive that needs guarding, lubrication, and tension checks.

Standard and Heavy-Duty CDLR Specifications

Note how capacity is stated: pounds per linear foot, tied to support spacing. Doubling support centers from 5 ft to 10 ft cuts rated capacity by roughly two thirds on the standard model, so floor support layout is part of the load calculation, not an install detail.

Zero-Pressure Accumulation on CDLR

Zoned CDLR accumulates pallets without contact. The Hytrol 25-CREZD handles 1,000 lb per linear foot with a maximum unit load of 3,000 lb, using 60 in accumulation zones as standard. Zone control runs on EZLogic, which combines photo-electronic sensing with discrete electronic logic rather than a PLC or pneumatic logic components.

Accumulating pallets without back pressure matters at stretch wrappers, palletizers, and shipping lanes, where a queue pressing forward damages loads and jams the release. On case handling lines, the equivalent function comes from zero-pressure accumulation conveyor.

When CDLR Is the Wrong Choice

CDLR handles general heavy loads in dirty environments, but pallet conveyor systems usually mix types by load condition. Drag chain conveyors carry pallets with formed feet, irregular bottoms, or extreme heat up to 6,000 lb. Plastic belt and mat-top conveyors support unstable or footed loads that rollers cannot. Turntables and right-angle transfers change direction without changing orientation.

The deciding factor is the bottom of the load. A stringer pallet in good condition rides rollers fine. A thermoformed plastic pallet, a damaged stringer, or a slip sheet does not.

Sizing Rules That Apply

Roller centers follow the load, not the catalog. The shortest load must sit on at least three rollers at all times, roller diameter and gauge are selected by dividing the heaviest unit weight across the rollers beneath it with margin, and width is product width plus clearance with guardrails where loads can skew, as covered on roller conveyor systems.

For pallet work specifically, capacity planning starts with pallet design, weight, and condition, then throughput, accumulation needs, and integration points such as palletizers, AS/RS, stretch wrappers, and dock doors.

Guarding and Maintenance on a Chain Drive

OSHA requires that all sprocket wheels and chains be enclosed unless they are more than seven feet above the floor or platform, and where a drive extends over other machines or working areas, protection against falling parts is required. Factory chain guards meet that on the equipment as shipped, which means the compliance risk lands on guards removed for service and not reinstalled.

Chain tension, sprocket wear, and bearing condition are the recurring service items, and clearing a jam inside a guard is servicing under the lockout standard.

CDLR Systems Through HOJ

HOJ designs pallet conveyor around your pallets, loads, and throughput targets, monitors and maintains the drives, rollers, and sensors that fail most often, and keeps parts in stock with 70+ vehicles in the field. Consulting, engineering, equipment, install, and service sit with one accountable team.