Precision measurement and adaptive solutions for high-quality stator production in powertrains
Batteries or fuel cells provide the energy. The drive train ensures that the wheels move. The drive train can be subdivided into the electric motor, consisting of stator and rotor, and the power electronics. Especially in the production of stators, our products are used in numerous manufacturing steps.
For example, the thicknesses of the lacquer layers of the copper wires are measured inline and directly after decoiling. The detection of varnish residues after paint stripping and before laser welding is also crucial for high laser welding quality. This is because if paint residues are still present, they melt during laser welding and can lead to the formation of pores. The required bonding cross sections could then no longer be guaranteed.
But laser welding also calls for innovative solutions. The pins to be welded sometimes have different heights, the individual pins can also be twisted in the plane and there can be gaps between the pins. Pins can be cut differently, and reflections from the clamping device also do their part. To meet these challenges, we have adapted our products to adaptively adjust the laser welding process at any time and quickly: for the highest quality in stator production.
Solutions for your manufacturing steps in powertrain
Measuring the coating thickness of copper hairpins, detecting cracks in hairpin lacquer, monitoring the laser-stripping of hairpins, and detecting lacquer residues after stripping hairpins are critical inspection tasks for the production of stators and hairpins. The high electrical properties of hairpins are a key factor to be taken into consideration when selecting the measurement technology.
It is also important to check if the enamel coating is thick enough to avoid short circuits, ensure damage-free enamel coatings with no pinholes or blisters, detect any blow-outs, measure the shape of weld joints, and check for any coating residues on hairpins.
For each of these specific tasks Precitec has exactly the right solution:
- Our CHRocodile CLS 2Pro line sensor is ideally suited to detecting any pinholes and blisters at a high inspection speed. It covers wide areas in a single measurement (up to 20 mm line length) and can recognize even the tiniest errors.
- Our Flying Spot Scanner 310 detects residues over the entire wire width and precisely measures the thickness of enamel – down to 2 µm. It delivers fast measurements at speeds of up to 70 kHz.
- Our CHRocodile 2K and CHRocodile 2 IT are ideal for efficient punctual measurement of the thickness of a wide variety of coatings on all four surfaces around the wire. Both devices use point probes to deliver precise, high-speed measurements of enamel thickness – down to thicknesses of 2 µm, at up to 70 kHz measurement rate.
For electromobile drive technology, series production of electric traction motors is to be made possible flexibly and in large quantities. This requires high-precision, process-stable manufacturing systems.
In the production of so-called hairpins, hairpin-like copper wires are inserted into grooves, twisted and laser welded. Monitoring the copper welding process results in reproducible and high-quality welded joints with good conductivity. A high tethering cross-section, minimal spatter formation, and reduction of void formation are achieved.
The ScanMaster offers an attractive scanner welding solution. It combines high-precision distance measurement to the workpiece (z-position), auto-focus (z-correction), perfect illumination and thus the use of a fast algorithm for position detection (x-y-position) as well as process monitoring.
Further fields of application in e-mobility
Fuel cell
A fuel cell consists of numerous bipolar plates that have to be welded gas-tight. In most cases, the welding speeds are very high - as are the quality requirements for the weld seam. In addition, the geometric parameters of the bipolar plates must be precisely maintained to ensure high fuel cell performance. We measure these with our 3D measurement technology sensors.
