As part of the project, the technical feasibility of the approach and the benefits of the targeted technology are to be examined in more detail. The aim is to use the theoretical advantages such as to prove better thermal connection and higher volumetric power density by setting up demonstrators. For this purpose, manufacturing technologies are to be developed in order to automatically manufacture coil bobbins from aluminium foils and to make electrical contact in a process-reliable manner. Furthermore, the overall technical-economic benefit for use in series is to be evaluated.
Figure: Magnetic linear actuator; Source: FAPS, FAU; Coburg University of Applied Sciences
Linear actuators are used in almost all technical and non-technical areas. In industrial production, for example, they are used to sort components as ejectors on conveyor belts. However, particularly powerful and responsive linear actuators are also required for positioning, lifting, applying pressure, etc. Should these also be used in limited installation space, such as for shifting gears in automatic transmissions, actuators are usually used, which are based on the principle of the force effect of static magnetic fields (Lorentz force).
As part of the project presented, methods are to be developed with which the power loss that occurs during operation can be better dissipated. In the first step, the enamelled copper wire is to be replaced by an anodized aluminium foil. In the second step, the thermal connection of the winding body to the housing is improved with the aid of a thermally conductive insulation film. As a result, the force applied to the product can be increased or the size can be reduced, while at the same time reducing production costs. Improved dissipation of the power loss makes it possible to load the winding body with a higher current and thus to increase the force effect. If the force is to be retained, the higher current can reduce the number of turns and thus the material and installation space. Compared to enamelled copper wire, a winding body made of aluminium foil has the potential for significantly better heat dissipation, so that higher currents can be used here. However, with the same installation space, the losses that occur increase due to the poorer electrical conductivity. In addition to the technical advantages, the winding body made of aluminium foil also has economic advantages. The raw material price of aluminium is around a factor of 3.5 below that of copper foil. In addition, the weight of the actuator can also be significantly reduced through the use of aluminum.
Benefits and economic importance for SMEs
The participating SMEs are enabled to develop innovative technologies for the electromagnetic energy converter market and to broaden their product and service portfolio. The current situation of the medium-sized automotive supplier industry represents a challenge especially for smaller companies that have to cope with the change towards a higher degree of vehicle electrification. The processes developed in the project offer SMEs great potential for use in other types of electromagnetic transducers, such as electric motors or inductors, which, in the context of electric mobility, can compensate for falling sales figures for traditional combustion engine technologies.