The structural transformation towards electromobility poses enormous challenges for automotive suppliers, because new materials and production technologies are necessary. The occurrence of critical material defects is prevented by non-destructive material testing, for example by Computed Tomography (CT). VisiConsult, as a provider of innovative X-ray solutions, has already been able to install several full automated in-line CT systems at leading automotive supplier. One typical inspection is necessary for short circuit rings.
VisiConsult’s cooperation partner in the field of electromobility is breuckmann eMobility GmbH, a subsidiary of Breuckmann GmbH & Co. KG, that offers casted rotors for electric motors. Within the rotor a laminated core is positioned between the short circuit rings which are connected to each other by aluminium. While casting the short circuit rings the biggest challenge is that the aluminium needs to be sufficient fluid when arrive at the end side of the laminated core. If this is not attained, pores come up and depending on size they are tolerable or lead to discard of the rotors. While small pores are harmless discontinuities in the material, large pores reduce the strength of the short circuit ring. In order for it to be sorted out accordingly, an inspection by Computed -Tomography and Automatic Defect Recognition (ADR) is indispensable.
VisiConsult has been able to integrate many CT solutions into inline productions, so their customers benefit of a 100% inspection without any waste of time. Directly after the casting the rotors can be moved to inspection because the conveyer drives through a cooling tunnel. Due to this constant temperature condition during inspection are achieved. Subsequently, a robot positions two rotors in the X-ray cabin, in which two X-ray tubes are located.
As a result, one X-ray cone can detect in its centre two shorting rings that lie side by side. That way four short circuit rings are scanned at once. VisiConsult manufacturer of special machines for X-ray was able to install the complete test cell as a black box. The operator doesn’t need any knowledge in X-ray or the process.
With loading and unloading, the inline solution is currently available in a cycle time of 42 seconds per rotor. In addition to the time advantage, the double x-ray source equipment also serves a more accurate scan and ensures greater system availability through redundancy.
According to the customer’s request, the subsequent analysis can be carried out according to the P202 standard by VW or other car manufacturers. With this system it is possible to perform 3D analyses, which means that it can be inspected 100% non-destructively.
If a pore size goes beyond that of a discontinuity, it is classified as a material defect and categorizes a component as not OK (n.i.O.), which leads to the sorting out of it.
Lennart Schulenburg, Commercial Director at VisiConsult, explains: “In addition to the evaluation results, our systems also provide extensive information about upstream processes, such as casting. With this information, our customer’s QM can be further optimized and monitored in real time. This functionality is part of our Industry 4.0 strategy and provides tremendous value. ”