General news
KeDrive – Cost-optimized, multi-axis drive solutions _2009-03-25
Multi-axial, electrical drives are used extensively, whether for robot applications, electric injection molding machines or machine tools. Up to now, in practice these tasks were dealt with by a number of parallel, single-axis modules or multi-axial systems. However, as the following example of an electrically-powered injection molding machine demonstrates, the intelligent combination of both system concepts by means of KeDrive (see Fig. 1) can cut the total costs of the drive solution by some 20 per cent. This shall be exemplified by an electric injection molding machine.
For injection, mold moving, plastication, ejection and nozzle movement, a typical injection molding machine has five axes with differing power requirements.
An initial approach is to operate the machine with five individual axis modules, each of which consists of a rectifier for the feeding of the DC voltage link and an inverter for the control of the motor (see Fig. 2). Modules from the KeDrive D4 series can be used for this purpose and this drive train is predestined for single-axis application up to high power levels. Converters, capable of delivering up to 210A, integrate the supply element for the feeding of the DC voltage link and the inverter for motor control into a single device.
However, the KeDrive D6 drive system, which is tailor-made for multi-axial solutions, is far better suited for employment in injection molding machines. It consists of a power supply device and modular, inverter axis modules, designed for current of up to 350A, which ensure maximum application dynamism.
When utilizing the KeDrive D6, one can take advantage of the fact that during applications such as injection molding, not all the drives need to be used simultaneously. As the injection axis has the largest power input requirement, supply is dimensioned to its demands. The drives for mold movement and plastication both require 70 per cent of this maximum power level, while ejection and pressing need 25 per cent.
A drive system comprised of KeDrive D6 components feeds a central power supply unit via the common DC voltage link of the five inverter axis modules. For additional optimization, the last two single axes can be replaced by a double-axis module for the ejection and pressing axes, which have the lowest power requirement (see Fig. 3).
The intelligent combination of the KeDrive D4 and D6 solutions also provides a further cost reduction, for when the D6 supply module is replaced by a D4 converter, the injection axis, which is the most powerful, can already be driven. The other D6 inverter modules are supplied via the joint, DC voltage link. As a result, the drive system is reduced by a further device. The optimum system configuration is shown in Fig. 4.
Other applications, in which an axis with a markedly higher power requirement is combined with weaker axes, offer similar potential for economies.
An initial approach is to operate the machine with five individual axis modules, each of which consists of a rectifier for the feeding of the DC voltage link and an inverter for the control of the motor (see Fig. 2). Modules from the KeDrive D4 series can be used for this purpose and this drive train is predestined for single-axis application up to high power levels. Converters, capable of delivering up to 210A, integrate the supply element for the feeding of the DC voltage link and the inverter for motor control into a single device.
However, the KeDrive D6 drive system, which is tailor-made for multi-axial solutions, is far better suited for employment in injection molding machines. It consists of a power supply device and modular, inverter axis modules, designed for current of up to 350A, which ensure maximum application dynamism.
When utilizing the KeDrive D6, one can take advantage of the fact that during applications such as injection molding, not all the drives need to be used simultaneously. As the injection axis has the largest power input requirement, supply is dimensioned to its demands. The drives for mold movement and plastication both require 70 per cent of this maximum power level, while ejection and pressing need 25 per cent.
A drive system comprised of KeDrive D6 components feeds a central power supply unit via the common DC voltage link of the five inverter axis modules. For additional optimization, the last two single axes can be replaced by a double-axis module for the ejection and pressing axes, which have the lowest power requirement (see Fig. 3).
The intelligent combination of the KeDrive D4 and D6 solutions also provides a further cost reduction, for when the D6 supply module is replaced by a D4 converter, the injection axis, which is the most powerful, can already be driven. The other D6 inverter modules are supplied via the joint, DC voltage link. As a result, the drive system is reduced by a further device. The optimum system configuration is shown in Fig. 4.
Other applications, in which an axis with a markedly higher power requirement is combined with weaker axes, offer similar potential for economies.
