Felss Rotor shaft for Hybrid vehicles

The Felss Rotor shaft is produced by a newly developed production method that combines rotary swaging , axial forming and heat treatment intelligently together. With this method, the hybrid shaft can be realized hollow and with a much simpler plug-in spline.


Rotor shaft

Lighter
Lighter
Weight-optimized use of material through intelligent material distribution.

New technologies in automobile manufacturing, such as for hybrid engines, involve new challenges for machine construction designers. Their overall geometry is very complex in most cases. In order to produce a transmission shaft with such accuracy and efficiency in large quantities, the forming and tube specialists of the Felss Group are developing suitable solutions during testing and in close consultation with automotive customers - starting from production planning up to the construction of the component itself.


Lighter, more economical and more dimensionally stable for hybrid cars

The Felss hybride shaft is made out of a tube, which leads to an enormous material and weight saving.
The Felss hybride shaft is made out of a tube, which leads to an enormous material and weight saving.

Felss Rotaform Deutschland is one of the component manufacturers within the Felss Group and is a specialist in rotary swaging, axial forming and other forming processes. Erhard Sepp, former Sales Manager at Felss Rotaform, recalls the original design plans of a customer in the automobile sector. According to these plans, a stub shaft spline was to be pressed onto a massive tube blank. The specialists at Felss Rotaform however were skeptical about the process reliability and process efficiency. “The spline was to cover the whole surface of the massive component. We had never tried anything like this before. It was very difficult to guarantee dimensional stability on a scale like this”, explains Sepp.


Rotor shaft experts: Felss Rotaform

Eckhard Morlock: “Altogether, the development phase of the “new” hybrid shaft at Felss Rotaform and Felss only took about five months. For similar workpieces, it often takes twice as long.”
Eckhard Morlock: “Altogether, the development phase of the “new” hybrid shaft at Felss Rotaform and Felss only took about five months. For similar workpieces, it often takes twice as long.”

Felss Rotaform and Felss designers, together with the customer’s engineers, then developed a modified transmission shaft that can be produced from a tube, thereby facilitating a far more efficient and material-saving production process. The stub shaft spline on the outside has been replaced with a lamellar surface for the force transmission. Together with a small external spline, this geometry is applied during different rotary swaging and axial forming processes. Other production steps such as rotating, tempering and grinding are integrated into the overall process. We are responsible for the whole production and guarantee the highly accurate and efficient manufacturing of the rotor shaft”, says Eckhard Morlock, Technical Felss Rotaform Manager. Altogether, the development phase of the Felss rotor shaft only took about five months. Similar projects in the area of machine construction often take twice that long.


Reduced component weight

Fels Hollow rotor shaft
Felss Hollow rotor shaft

Manufacturing the rotor shaft from tubing using the rotary swaging process is not just highly accurate and quick. The weight of the component is also significantly reduced. This is key factor when it comes to electric vehicles, as for every kilo that is shed, the range of the vehicles is increased in spite of the relatively heavy batteries. The newly developed production process that intelligently links rotary swaging, axial forming and metal cutting processes, offers very good chances in the future for Felss Rotaform. “We are currently in the process of manufacturing a different drive shaft, in very small quantities, for a new electric car for a German car manufacturer – these production figures may of course rise if the hybrid technology in automobile manufacture proves to be extremely successful”, confirms Morlock.


Felss, your design partner

Make & Buy: Mechanical engineering and component manufacturing all in one hand.
Make & Buy: Mechanical engineering and component manufacturing all in one hand.

When it comes to complex workpieces, the machine manufacturer Felss sees itself as a development partner who is already “onboard” even at the construction and design stage of the workpieces. Winfried Richter, former Managing Director of Felss, can justify this philosophy based on this project: “The component is not just a complex shape. It must also be capable of withstanding the torques of the engine and must therefore have the appropriate wall thickness. When designing a piece like this, many constructors would never have imagined that a shape like this could be created from just one piece of tubing. Many would probably even try to hollow out the inside – an unnecessary waste of material. We’re taking a different route from the start with our customers.”


Wolgang Haggenmüller, Business Development and Andreas Härter, Prozess Development
Wolgang Haggenmüller, Business Development and Andreas Härter, Prozess Development.