Unlike existing hybrid concepts that blend hydraulics with electrics, Davi's new all-electric steel plate rolling machine uses no hydraulic components whatsoever. PHOTO courtesy Davi.
As the first of its kind, a new all-electric steel plate rolling machine is expected to revolutionize the industry with new levels of speed, precision, efficiency, and productivity, according to its maker.
Unlike existing hybrid concepts that blend hydraulics with electrics, this system uses no hydraulic components whatsoever. This adaptation of electric power to all phases of rolling machine operation also greatly improves ease of maintenance and energy efficiency, while making for a more quiet, compact machine that ensures hassle-free installation.
The new all-electric machine platform, called e-POWER, is from plate and angle rolling equipment manufacturer Davi Inc. In terms of electric plate rolls in the rolling market future, e-POWER is a direct result of the company’s dedicated research and development department’s capability to design new products that push the boundaries of performance.
While a hydraulic roll machine bends plates at speeds of about 20 feet per minute, the all-electric e-POWER processes material at 32 feet per minute, or 60 percent faster. Such processing speed significantly increases output, shortens turnaround times and improves productivity, all while maintaining high part quality.
A distinguishing benefit of an electric rolling machine is the ability to move multiple axes simultaneously. To maintain sufficient fluid pressure and flow, axis movement on a hydraulically driven machine is limited to two axes at a time. On an electric machine, separate motors are directly splined to the machine rollers and electrically controlled actuators can move up to nine axes concurrently. Maximum speed and torque are available immediately no matter how many axes are in motion, without waiting for separate pairs of axes to complete their jobs. Transitions between axis movements are smooth and facilitate creation of complex bends.
Production time savings result when some movements in a process can be accomplished while other actions are happening. In separate steps, a hydraulic rolling machine squares the material in the rollers, backs the material up then raises the side rolls for a prebend operation. An electric machine, with its capability to move multiple axes simultaneously, brings the pinch roll up after squaring the material while at the same time it performs the prebending. Cycle times are thus 40% faster than with a hydraulic machine, Davi states.
When it comes to energy efficiency, an all-electric roll machine consumes power only when it is actively moving machine components. When there is no movement, power consumption is only necessary to support the image on the machine’s computer control screen. Hydraulic machines, on the other hand, require continuous power to maintain fluid pressure even when no movement is occurring.
In another power-saving feature, Davi’s all-electric plate machines have a start-and-stop feature similar to that on contemporary automobiles, utilizing energy only when required. Plate rolling processes routinely include idle times for part loading and other operations, and the e-POWER energy use on-demand supports energy conservation and contributes to sustainability and environmental responsibility. As a result, power cost savings can range from 25 percent to 35 percent.
In comparison, all-electric rolling machines consume about 50% less power than hydraulic machines and approximately 30% less than hybrid electric/hydraulic units. Because electric machines can roll material 40% faster than hydraulic machines, total operating cost can decrease by 60% compared to full hydraulic machines.
For increased accuracy, electric activation enables precision control of machine components. Standard positioning accuracy for a hydraulic machine is about 0.1″ while electric machines consistently provide accuracy of 0.05″. It should be noted that thickness and accuracy of the plate being processed affects overall accuracy. If the accuracy of the plate itself varies widely, the accuracy of the bending process diminishes. Additionally, plate rolling accuracy facilitates blending of multiple part radiuses, and can benefit downstream operations such as robot welding that require precise joint matching between components.
High-volume job shops, high-precisions applications and OEM manufacturers are prime candidates for these unique all-electric Davi systems. PHOTO courtesy Davi.
Electric rolling machines apply to all applications. However, in some instances, a hydraulic machine could be a more convenient solution. A small shop that does a high mix of low-volume jobs may not require the advanced speed and accuracy of an electric machine and would prefer not to invest in that level of technology. However, high-volume job shops, high-precisions applications and OEM manufacturers are prime candidates for these unique all-electric system.
For instance, the simplicity of an electric power delivery system minimizes maintenance requirements. Hydraulic hose swelling and fluid leakage affect a machine’s movement speed and accuracy. An all-electric machine has no fluid hoses or connections to leak or clog, thus reliability increases to greatly reduce the need for service interventions and machine downtime. Without the pumps, hoses, valves and connectors of a hydraulic system, an electric system has significantly longer routine service intervals.
Plus, the plug-and-play nature of the electric actuators that move machine components also simplifies service requirements. Shop staff can simply replace a faulty actuator without the need for machine disassembly and downtime. In many cases a facility’s electrician can perform the switch without requiring a visit by factory service personnel.
With floorspace at a premium, manufacturers seek to minimize their machine footprints while maintaining their functionality and productivity. The elimination of the hydraulic controller and other equipment needed to maintain hydraulic pressure helps conserve valuable floor space, improves employee access to the machines and makes material handling and manipulation of completed parts easier. The more compact footprint of the e-POWER also facilitates shop floor planning and makes machine installation and integration more straightforward and less time consuming.
Besides being larger in size, hydraulic plate rolling machines generate significant amounts of noise. Conversely, electric plate rolls are essentially silent in operation, both in standby and operational mode, reducing noise pollution in the shop and improving employees’ work environment.
For further ease of use, the e-POWER’s control lets operators program the machine and automate rolling parameters that include speed, pressure and bending angles. The programs direct machine movements to occur smoothly and simultaneously to maximize efficiency and output. Customizing programs makes it possible to expedite specific jobs.
In an increasing number of industrial applications, the convenience, availability and flexibility of electric power is superseding traditional energy sources such as fossil fuels as well as operating processes including hydraulics. Worldwide efforts toward sustainability are drawing attention to these alternatives and industrial contributions such as the new electric plate rolling machines from Davi constitute a positive move towards progress and profitability.
