Concept Development of anElectromechanical Cylinder : With a Cascade Gear Unit

Abstract: A new invention has been developed by CorPower Ocean; a mechanical rack and pinion solution called a cascade gearbox. The primary function of the gearbox is transforming a linear motion into a rotational motion. The novelty is its unique properties; it is capable of combining heavy loads and high velocities, and at a high efficiency. CorPower Ocean is aiming at finding applications where the gearbox’s unique properties can be of use. If the gearbox is combined with a motor it forms an electromechanical actuator. Therefore, an investigation of applications using actuators has been targeted. More specifically, the master thesis assignment was to examine in which applications the transition of a cascade electromechanical actuator was technically viable. Research questions that derived was to answer if an implementation of an cascade electromechanical cylinder is technically feasible and if it implicates improved results regarding environmental related goals. The methodology executed to finalize the project included several stages. The first stage was the background study which consisted of reviewing trends and gathering technical data for case studies of targeted applications. The targeted applications were heavy lifting equipment and injection molding machines. With the help of CorPower software, gearbox dimensioning examples were drafted and could be evaluated from a size and weight perspective. To further evaluate potential applications, interviews were conducted with targeted equipment manufacturers. The selection of applications was completed by evaluating the interview responses and the drafted gearbox examples. Chosen applications were ultimately a nine tonnes forklift and an empty container handler, mainly due to good customer response, integration ability and potential of performance enhancement. An optimisation was performed to achieve a concept solution that satisfied customer needs such as low cost and a slim design. In order review the business cases in each application, energy savings and performance cases were conducted, benchmarking against the hydraulic solution. In the ECH case, the energy saved was 54% and the productivity increased with 9.6%. In the forklift case, the energy saved was 52% and the productivity increased with 1%. Both of applications have great potential of a transition from hydraulic cylinders to electromechanical cylinders in terms of implementation and technical feasibility. The final concept solutions exceeded the hydraulics in performance, retaining a slim and acceptable size and design. Furthermore, this sector of heavy lifting equipment had high potential for electrification which can contribute to reduced emissions and fuel savings. Keywords: electromechanical cylinders, concept development, cascade gearbox