Rethinking mobility. Taking on responsibility.

Students and trainees create a "kneebike"

At Rheinmetall we are concerned with a wide variety of developments in the fields of mobility and security. For many people cycling means mobility. If they are no longer able to do this, e.g. due to pain, this often results in severe limitations. A "kneebike" could be a suitable solution for them.

The "kneebike" is a bicycle with a kneeling chair as a seat. The advantage of this kneeling chair is a sitting position that places particularly little strain on the back and thus relieves the spine. However, the driver can no longer pedal in this position.

How does an e-bike become ergonomic?

A committed group of apprentices and students is addressing this question from the cross-location Design Thinking Workshop of various Rheinmetall Automotive companies. Their plan is to install an electric wheel hub motor on the rear axle to drive the vehicle.

Thorsten Kühnel (Chief Digital Officer, Rheinmetall Automotive AG, Neckarsulm) and Randy Foster (Technical Training Manager Hardparts Division, KD Gleitlager GmbH, St. Leon-Rot) supported the project so that it could quickly enter the prototype phase.

Telephone conferences are held at regular intervals for communication between the teams to ensure the success of the prototype.

A "kneebike" goes on a journey

Following the delivery of the components, the project is now being implemented in practice at the sites. In order to make the best possible use of the respective competences, each project participant contributes according to his or her educational, experience or study background.

Station 1: Frame construction in St. Leon-Rot

The frame construction in St. Leon-Rot at KS Gleitlager GmbH represents the start of the project. First of all, a frame made of square profiles is created there. The construction is the responsibility of mechanical engineering students Marco Hornung from KS HUAYU AluTech GmbH in Neckarsulm and Yannik Krüger from KS Gleitlager GmbH in St. Leon-Rot. In close cooperation with the electronics team headed by Glenn Töws and Laurin Jacobs from the Pierburg GmbH plant in Neuss, the frame is designed in such a way that all electronic components consisting of battery pack, control unit and wheel hub motor can be accommodated without any problems later on.

Think ahead. Keep thinking. Planning is everything.

Several trainees around André Nöckel manufacture the frame in the training workshop, including welding of the square profiles, drilling, turning and milling of further structural parts.

Construction of the frame - plan view

Construction of the frame - plan view

Two profiles are arranged parallel to each other and form the basic structure. The profiles are connected at four points. These points are used to hold the front fork including wheel and handlebars, the battery pack with control unit, the seat post and the rear wheel axle.

Position adjustment - side view

Position adjustment - side view

The front axle, consisting of wheel, brakes, fork and handlebars, comes from a purchased bike and is welded to the self-built frame by means of an adapter piece. In order to fix the battery pack and the control unit in a subsequent step, an additional plate is riveted under the profiles. One of the two square profiles must also be designed to be removable, otherwise the wheel hub motor could not be installed in Neuss.

The positions of the leg rests and the saddle height need to be adjustable, similar to a conventional bicycle. Efficient solutions have also been developed for this. The leg rests themselves consist of wooden boards, which are fixed with a layer of foam and fabric.

After completion of the first project station, the frame will be transported to the Neuss and Hartha sites, where the electronic components will be installed and first test drives will be carried out.

Station 2: Electronics in Neuss and Hartha

In close cooperation with the electronics team in Neuss, led by Glenn Töws and Laurin Jacobs, a dual student of mechatronics, the frame was designed so that later on all electronic components could be integrated into the system. The project teams held telephone conferences at regular intervals for communication.

"The Corona crisis has of course thrown everything into confusion. We actually wanted to present the finished prototype in summer," says Ian Traffehn. The 26-year-old mechanical engineering student took over as project manager at the beginning of the year and organised the cooperation, kept minutes and maintained schedules. "In Neuss, we printed the battery holder via 3D, programmed the motor controller and welded the battery packs together. Finally, the electronic components with the wheel hub motor have to be installed and the first test drives have to take place," says Traffehn. Together with Glen Töws, he now wants to complete the project. At the same time, they are completing their studies.

What particularly motivated them all this time: "We were taken seriously by the decision-makers and were allowed to implement our own project independently from start to finish," says Glenn Töws. "The exchange between locations was also great. Everybody could get involved. This meant that everyone was very well integrated," adds Ian Traffehn.

"You should never underestimate the new generation," says training manager Randy Foster. "The team broke new ground independently. And, we gave them the necessary freedom. The result is impressive."

We are eagerly awaiting the last development station of the kneebike.

Station 3: Documentation in Papenburg and Berlin

Soon you will find out more about the final steps and the completion of our kneebike prototype.

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