A Tier 1 supplier is tasked with producing an internal ring gear for a planetary stage in an electric axle, ready for assembly. In an electric transmission, this component acts as the fixed internal “counter gear” in which the planet gears roll. It therefore has a direct impact on how efficiently torque is transferred from the electric motor to the wheels and how smoothly the drivetrain operates in the vehicle.

Especially in electric vehicles, where secondary noises are more noticeable, gear quality has a direct influence on noise behavior and therefore on perceived driving comfort. At the same time, the component must withstand high alternating loads over the long term, for example during acceleration and recuperation.

On the PITTLER pSkive, the internal ring gear is machined so that it leaves the machine ready for assembly in a single setup. First, the internal gear is produced by gear skiving. The tooth edges are then deburred directly in the same setup, ensuring that no burrs interfere with subsequent assembly and that no particles enter the transmission area. The relevant reference surfaces are then finish-turned, allowing the internal ring gear to be precisely positioned and clamped in the transmission housing.

Because gear skiving, turning, and PRÄWEMA VarioChamfer deburring are carried out without reclamping, the positional relationship between the internal gear and the reference surfaces remains stable and reproducible. This is a decisive factor in ensuring repeatable quality from the very first series-production part.

The result is an internal ring gear that comes out of the machine “finished”: with a clean internal gear, deburred edges, and precise reference surfaces that are perfectly aligned with one another. For the customer, this means fewer process steps and less handling between multiple machines, reducing non-productive times and throughput time. At the same time, process reliability increases because typical reclamping errors are eliminated and less rework or scrap is generated.

Ultimately, this also pays off in the vehicle: the planetary stage runs more smoothly, noise is minimized, and efficiency remains high. Exactly the combination modern electric drives require.

In this case, the task is to produce a stepped planet gear for an electric vehicle. Unlike the internal ring gear, the planet gear is the “working” gear of the planetary stage. It transmits forces within the planetary gear set and has a significant impact on efficiency, noise, and service life. Especially due to the constant load changes during acceleration and recuperation, high quality is essential.

Production is demanding because a stepped planet gear typically has two different gear sections. Conventionally, such gears are produced by hobbing, which, depending on the circumstances, can take 3 to 8 times longer than PITTLER Skiving.

This is precisely where the pSkive DUO configuration comes into its own. With two driven skiving spindles, two skiving cutters can be mounted at the same time and used without retooling. This can be done either as a roughing/finishing strategy or with two different tools for the two gear sections.

In practice, the component is clamped only once. The first gear section is machined with the appropriate skiving cutter. The machine then swivels to the second skiving cutter without a tool change in order to machine the second gear section. This not only makes the process faster, but also significantly more stable, as retooling effort, additional interfaces, and potential sources of error are eliminated.

Because there is no reclamping during the process, the timing between the two gear sections is significantly more precise. The result is a clear, reproducible process: two gears on the same component in a single process.

For the customer, this means higher productivity through reduced changeover times and greater process reliability through lower quality variation. In the vehicle, the result is a smoother-running planetary stage and more efficient power transmission over the entire service life.