This post is written by Gregg Goodner, President of Hytrol Conveyor Co., Inc., headquartered in Jonesboro, Arkansas.

Just a few years ago, the material handling industry thought 24-volt conveyors had to be driven via a small, high RPM motor with gearing assembly, all fitted within the tube of a drive roller; thus, the term motor driven roller (MDR). In recent years, however, a new technology has come along offering a much different solution. This new technology utilizes a 24-volt motor mounted external to the roller rather than inside the roller.

Externally mounted 24-volt motors vs. MDR

Externally mounted 24-volt drive motors bring many advantages over motors mounted inside the tube, as in the case of MDR. First of all, they are designed to operate more efficiently. How, you ask? Although 24-volt DC conveyor technology has always been known for its low power consumption, the externally mounted drive motor was designed to operate without the use of gears and the motor windings were designed with lower resistance.

Both equate to a higher efficiency operation and lower noise when operating. Another benefit of the external motor design is that it sports a design life of more than 125,000 hours--six times the life expectancy of an MDR. This is a huge benefit considering the fact that customers are expecting greater reliability while operating their equipment more hours per year. This robustness comes as a result of several design improvements including fewer moving parts (no gears equals less heat generated) and lower motor RPM to accomplish the desired conveyor speed.

Another important advantage of this innovative technology is the common motor design. This means the same motor can be used across all conveyor widths and speeds, greatly reducing the hassle in supporting a complete conveyor system. This is not the case with MDR. With the MDR motor being inside the roller, it requires a unique drive roller for each conveyor width. This means excessive spare parts must be stocked in order to adequately support the system.

Additional advantages of 24-volt, external drive conveyors:

• No Air Requirement - If air isn't already needed to operate other equipment in your facility, then the use of externally driven conveyor eliminates the need and cost of having compressed air systems in your facility.

• Decentralized 24-volt DC Drive System - Simple to install, greater intelligence, and no large centralized drive systems to maintain; externally mounted motors also allow one to change out motors without shutting down the line.

• Flexible System Configuration - This allows for more creativity in the design of your system because there are no space limitations due to large drive systems. The plug-and-play, electrical design allows for simple modifications for future demands.

• Variable Speed Adjustment - Flexible conveyor speeds that are easily changed with control cards or from a centralized point increase throughput options. Greater speed range and ability to control carton gap in areas where needed; reversible if needed.

24-Volt Meets Zero Pressure

Hytrol Conveyor Co., Inc. introduced our version of 24-volt DC conveyor technology--E24™--in the fall of 2007. Customers using E24™ also benefit from the fact that it can be combined with our patented EZLogic® zero pressure accumulation system.

Offering an advanced energy efficient solution, it actually shuts down power in accumulated zones and allows zones to "sleep" when cartons are not flowing, which means you're only paying to power the zones conveying product. The intelligence gain from combining these two technologies not only contributes to lowering your energy consumption, but also contributes to an overall lower operational cost -- truly a "green" solution.

Author: Gregg Goodner