For the visualisation of Traction‑X, a demonstrator was developed in a bachelor thesis.
This was manufactured with the help of additive manufacturing. To make the visualisation even more realistic, the demonstrator was driven by a DC-motor and a stepper-motor.
Many people are familiar with the statement: You can print anything! Theoretically, this is true, but it is not practical and does not make sense. It is also important to combine the many different processes.
Standard aluminium profiles for the frame and plastic parts from three printing processes were chosen as components.
Besides the FLM (Fused Layer Modelling) process, the SLS (selective laser sintering) and LS (laser sintering) processes were also used. When it comes to materials, it is also important to see which material makes the most sense. Components with a simple shape and low demands on strength and accuracy were printed from PETG (Polyethylene terephthalate glycol) filament using the FLM process. These are the black components on the demonstrator.
The rim parts were produced from PA 12 (polyamide 12) by laser sintering, then painted in silver.
The plain bearing, the ring gear and the motor pinion were also produced by laser sintering. As high wear resistance and good sliding behaviour are required, the material Iglidur I3 from the company Igus (https://www.igus.de/product/719?artNr=I3-PL-10000) was used here.
The drive shaft is the supporting part of the demonstrator. It connects the wheel to the frame. In order to avoid damage due to unexpected stresses caused by transport or improper contact with the demonstrator, for example, this was made of AlSi10Mg.
A Raspberry Pi is used to control the two motors.
The DC motor drives the outer rim, i.e. the tyre, via two gear stages.
The special feature here is that the gear stage located in the rim has double helical gearing.
Why this choice?
A helical gear has a smoother running behaviour and less noise compared to a degree gear, but axial forces are generated.
Therefore, either a helical or axial ball bearing must be installed to counteract the axial forces or, alternatively, a double helical gearing can be used, which does not generate any axial forces.
A stepper motor was used to simulate compression and rebound.
The damper unit consists of two units.
The upper damper unit consists of the upper damper connection, the stepper motor and the trapezoidal spindle. The lower damper unit consists of the lower damper connection and the trapezoidal nut.
The trapezoidal spindle and the trapezoidal nut convert the rotational movement of the stepper motor into an axial movement.