Safe, clean, economical, sustainable, pleasant and connected– these are the attributes of the car of the future. The drive train, light weight design, driver assistance systems and digitization are decisive. Given IFA’s prominence in the premium segment, IFA collaborates with the leading OEM in these endeavors. For example, IFA works on disconnect systems for propeller shafts to avoid the friction of the idly rotating shaft. This requires better corrosion protection measures, as the shaft cannot centrifuge splash water off the shaft in the vast majority of driving conditions. IFA reinforces propeller shafts and drive shafts for use in hybrid vehicles, which generate especially high values of torque. By using special alloy steel and thin-wall tubes, the weight increase can be compensated. IFA also develops low noise half shafts of battery-powered electric vehicles. As a last example, IFA develops telescopable shafts which protect the well-being of the passengers in case of a vehicle crash.
Electrical drives are an opportunity for IFA. Firstly, there are hybridized drives, meaning vehicles where an internal combustion engine is combined with an electrical motor. Such drives feature very high peak values of peak torque. For these IFA designs shafts and joints which are stronger and quieter as designs required thus far. Drive shafts are also instrumental in the recuperation of brake energy. This feature is a preeminent advantage of the hybridized drive train. Secondly, there are electric vehicles which are powered solely by a battery.
Eliminating drive shafts by installing the electric engine in the wheel is no option. Electrical motors are heavy. To guarantee driving comfort, wheels on the other hand must be as light as possible to minimize the undampened mass of the vehicle. Wheels must be designed to be able to pass curbs and railways at high speed with loss of air pressure and destructive deformation of the wheel, without harming the drive train. This is impossible without decoupling drive train and wheel with a drive shaft.
IFA respects the competition and is open for any input which may improve IFA’s products. Hence, IFA systematically compares the performance of her own products with that of the competitors. To this end, IFA operates a dedicated benchmark center with full-time experts, who select, procure, disassemble and test competitor products. The results are documented and explained in detail to IFA’s design teams. The willingness of the latter to incorporate other engineers’ ideas is key. The IFA board of management is personally involved to foster such openness.
Computer simulations lower engineering time and cost. The fit of the shaft in the vehicle can be simulated with a (digital mock-up, DMU). Physical cause-effect chains can be quantitatively proven. Improvement measures for design and production process can be initiated early in the production process. IFA performs a large number of simulations with a variety of the world’s most advanced computation tools, before a shaft may enter mass production.
Friction welding is the key process to connect joints and tubes to form drive shafts. An innovation of this process is self-centering friction welding, where the geometries of the weld partners ensure their coaxially after welding. The process parameters, the required geometries and a simulation of the evolution of the weld geometry during the process were developed in cooperation with researchers from Otto-von-Guericke-University in Magdeburg.
Drive shafts are fine tuned in the final stages of launching a new vehicles in order to eliminate remaining problems in the interaction of engine and chassis. IFA therefore complements the results from bench tests with those gathered during shaft operation in actual vehicles. Shafts are mounted in vehicles, which are equipped with sensors, microphones and cameras, to facilitate on-board surveillance of the shaft’s operation. Thus IFA can support the car maker while gathering valuable insights how to improve the shaft.