Successful conversion by reducing downtime
The Volkswagen plant in Kassel, Germany uses this technology for mechanical processing of transmission housings and in its foundry. To optimize housing production, the company focused on minimizing failures caused by defective control valves and associated production interruptions. Filters the closed loop system regularly clogged with swarf and required cleaning, causing extended periods of downtime for the entire production line.
After eliminating control valves and switching to Allweiler EMTEC-series of frequency-controlled screw pumps, uptime increased significantly. Energy savings vary, but at times can reach up to 68 percent.
The line's electronic controller needs less than a second to adjust motor speed to the pressure required by each individual tool. If a higher volume is required, speed is readjusted automatically. The new system is a package that includes the pump, frequency converter, and control logic and is optimized for use in machine tools, transfer centers, and transfer lines.
From the operator's perspective, the new system's fast reaction time is a major benefit. The optimal operating point is achieved from a starting stop in just 500 ms. The pumps require less maintenance than those of the old system, and have a longer service life because they are not operated continuously at their highest speed. The speed controller adjusts for normal wear without loss of pumping performance as it automatically increases speed, allowing for maintenance to be coordinated with the production process.
In most cases, smaller motors with significantly lower rated power are used. The pump operates only when the tool is in operation, protecting the filter preceding the pump. Downtime due to maintenance has been reduced by more than 90% — from 100 minutes per month to just six minutes which allows Volkswagen to produce an additional 200 transmission housings per month.
