About one third of the energy consumption of the rubber injection moulding machines is caused by the drive. The Maplan drive unit Cool Drive II, which is based on constant-volume pumps with a servo motor drive, allows adjustment of pump activity and hence the power required for the actual speed. The drive can thus save energy of as much as a sensational 70% because of the process-based cycle breaks of hydraulic consumption. Furthermore, there is a significantly lower energy input into the hydraulic oil, therefore changing oil is less often and oil coolant is not needed. This leads to a reduction of water consumption, and hence a further reduction of the total energy demands.
A beneficial side effect is noise reduction. Amidst movements of operation, the smooth running of the pump reduces noise level by up to 10 dB. During hydraulic cycle breaks, pressure generation produces largely no noise. This leads to an overall reduction of noise level by up to 50%. Another customer value of Cool Drive II has to do with the higher dynamic of servo technology which brings about an increase in machine performance by 10% and thus a further significant reduction in unit costs.
In the production of rubber moulded items, approximately 30% of the total energy consumption is used by the drives. However, despite the comparatively low proportion of energy costs in the total product manufacturing costs, the drives can still achieve significant savings using intelligent systems.
Due to the cost pressure imposed on the manufacturing industry, the potential of conservation in the future is gaining even greater significance.
Currently, the drive used is primarily generated by means of an asynchronous motor combined with electrically/hydraulically controlled pumps, which causes power loss in the form of heat. Above all, no-load running or flushing processes reduces drastically the overall efficiency of the drive system which depends on the machine cycle. Depending on each system, this burden of the drive results in a corresponding reactive power requirement.
In contrast, electric propulsion concepts in which electric power is converted by means of mechanical components directly into translational motions achieve higher efficiency and running speed.