Machining of electric motors, stator housing, battery trays

Press release: May 2021

Electric motor machining with just one tool

New CERATIZIT tool solution ensures process-secure, efficient finishing of the stator bore and bearing seats

The extreme pace of development and dynamics in electric mobility require innovative tooling solutions. Addressing this is CERATIZIT’s four-blade, controllable tool system for high-precision and efficient batch production of electric motor housings that ensures high process security and stability.

High tool functionality and performance are important elements in the production-ready machining processes demanded in automotive manufacturing. This includes easy handling of tools and minimal adjustment with maximum precision. These requirements apply equally in electric motor production. The housing machining, especially the stator bore, presents a particular challenge, due to the. These components are mostly thin-walled with the stator bore being relatively large. Ideally, this feature is produced in a single operation, along with the cover fitting (usually to a tolerance of H6) and bearing seat. The surface quality is also important and poses a challenge, as a roughness of Rz =6.3 µm or better needs to be achieved as a general rule.

CERATIZIT has developed a completely new system based on a slide tool with four blades that operate on the same diameter that delivers efficient production of electric motors. It makes use of a mechanical drawbar system for control via the NC control system, meaning the diameter and length of the bore can be programmed freely by the user.

CERATIZIT has developed a completely new system based on a slide tool with four blades that operate on the same diameter that delivers efficient production of electric motors. It makes use of a mechanical drawbar system for control via the NC control system, meaning the diameter and length of the bore can be programmed freely by the user.

The functional core element of the system is the drawbar, which is ground with high precision and precisely adjusted to the associated base body. Maximum precision is also required for the four slides, with each one ground individually into a slide chamber and drawbar to achieve minimal backlash. The slides have lateral oil grooves and high precision teeth. The tools are made from aluminium for weight reduction.

Advantages of the CERATIZIT tool system for e-motor machining
  • Production of different bore diameters with just one tool
  • Optimum concentricity between the rotor and housing (after assembly)
  • Four effective blades enable a high feed rate, which contributes to extremely high cost effectiveness.
  • Machining in one "shot" guarantees optimum concentricity of the bearing and stator bore.
  • The stable tool design ensures precise geometric and positional tolerance of the bores.
  • Ability to control the system means it can be used extremely flexibly – changes to contour and diameter can be controlled via the NC program
  • Low weight and tilting moment