Servo cables for high mechanical loads in solar off-road vehicle

Bend-resistant chainflex® servo cables were required for extreme thermal conditions.

Solar vehicles have been developed at Bochum University of Applied Sciences for over 20 years. One completely independent project is the SolarBuggy, which was originally created at the end of 2012 through the donation of a commercially available buggy. The current "Froggee" model was designed to cross the Australian desert in spring 2018 and set a new world record in the process. On board: chainflex® servo cables, which are ideally suited for thermal and mechanical loads on site.

Profile

What was needed: chainflex® -servo cable
Requirements: The cables must be able to withstand high thermal loads as well as mechanical loads during movement and vibrations, have a low weight and be able to be used in the smallest installation spaces with a minimum bend radius.
Industry: Automotive industry
Success for the customer: The chainflex® cables combine low weight with high load capacity and maximum mechanical durability. They can cope with bend radii of up to 7.5xd in the buggy, so that they can also be used in particularly small installation spaces.

Problem

Since the beginning of 2016, 16 students from Bochum University of Applied Sciences have been working on their current project to independently develop and build a solar-powered off-road vehicle. The team's aim was to design and develop their SolarBuggy entirely on their own in such a way that it could easily cope with the toughest conditions for off-road vehicles, sand and dunes. To achieve this, students from the departments of electrical engineering, mechanical engineering and mechatronics worked together in working groups. The aim of the project was to cross the Simpson Desert in Australia as quickly as possible with the developed vehicle in spring 2018, charged with solar energy and self-sufficient, thereby breaking the current world record of four days, 21 hours and 23 minutes. For the buggy, this meant a distance of 360 kilometres along the "French Line" from Purni Bore to Birdsville. To achieve this, 2.5 m2 of solar cells are mounted on the roof of the vehicle. With this in mind, all the components in the SolarBuggy have to be able to withstand the high stresses caused by the movement and vibrations that occur while remaining lightweight.

Solution

This also applies in particular to the chainflex® cables for connecting the motor controllers to the electric motors, for driving the vehicle and for the internal wiring of the contactors. A low weight and diameter as well as maximum mechanical durability are the strengths of the cables. The servo cables in the SolarBuggy have a special conductor structure that ensures a high current carrying capacity and withstands the mechanical load during movement and vibration so that there are no interruptions to the power supply. The cables are shielded, enable direct and alternating voltage and have a high electromagnetic resistance to external influences. They are very robust and are ideal for thermal loads in Australia. We offer chainflex® servo cables with or without inner jacket. Depending on the type, they are flame-retardant, coolant and oil-resistant and flexible at low temperatures. Tested under real conditions in our in-house laboratory, they ensure maximum service life and guaranteed reliability.
In the case of the SolarBuggy, the selected servo cable CF270.UL.350.01.D can withstand bend radii of up to 7.5xd for the smallest installation spaces. Thanks to their PUR-outer jacket, they are oil-resistant, halogen- and silicone-free and flame-retardant.

Overview of chainflex cables

"Alternative products rarely met all the requirements at the same time - in addition to the conductor cross section, the colour of the insulation, the shielding and the price were also important to us."

Kay Bollerhof, Team SolarBuggy